diff --git a/doc/conf.py b/doc/conf.py
index 1bcf5d559e..a721508deb 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -79,7 +79,8 @@
     'sphinxsetup': """%
 VerbatimColor={RGB}{242,242,242},%
 VerbatimBorderColor={RGB}{32,32,32},%
-verbatimradius=3pt%
+pre_border-radius=3pt,%
+pre_box-decoration-break=slice,%
 """,
 }
 latex_show_urls = 'footnote'
diff --git a/doc/latex.rst b/doc/latex.rst
index 4d16445040..c46ab6e29b 100644
--- a/doc/latex.rst
+++ b/doc/latex.rst
@@ -8,21 +8,26 @@ LaTeX customization
 
    \begingroup
    \sphinxsetup{%
-         verbatimborder=2pt,
-         verbatimsep=5pt,
-         verbatimradius=5pt,
-         VerbatimColor={named}{OldLace},
-         VerbatimBorderColor={named}{Gold},
-         TitleColor={named}{DarkGoldenrod},
-         hintBorderColor={named}{LightCoral},
-         attentionborder=3pt,
-         attentionBorderColor={named}{Crimson},
-         attentionBgColor={named}{FloralWhite},
-         noteborder=2pt,
-         noteBorderColor={named}{Olive},
-         cautionborder=3pt,
-         cautionBorderColor={named}{Cyan},
-         cautionBgColor={named}{LightCyan}}
+      TitleColor={named}{DarkGoldenrod},
+      pre_border-width=2pt,
+      pre_padding=5pt,
+      pre_border-radius=5pt,
+      pre_background-TeXcolor={named}{OldLace},
+      pre_border-TeXcolor={named}{Gold},
+      div.warning_border-width=3pt,
+      div.warning_padding=6pt,
+      div.warning_padding-right=18pt,
+      div.warning_padding-bottom=18pt,
+      div.warning_border-TeXcolor={named}{DarkCyan},
+      div.warning_background-TeXcolor={named}{LightCyan},
+      div.warning_box-shadow=-12pt -12pt inset,
+      div.warning_box-shadow-TeXcolor={named}{Cyan},
+      attentionborder=3pt,
+      attentionBorderColor={named}{Crimson},
+      attentionBgColor={named}{FloralWhite},
+      noteborder=2pt,
+      noteBorderColor={named}{Olive},
+      hintBorderColor={named}{LightCoral}}
    \relax
 
 Unlike :ref:`the HTML builders <html-themes>`, the ``latex`` builder does not
@@ -65,7 +70,10 @@ The ``latex_elements`` configuration setting
 
 A dictionary that contains LaTeX snippets overriding those Sphinx usually puts
 into the generated ``.tex`` files.  Its ``'sphinxsetup'`` key is described
-:ref:`separately <latexsphinxsetup>`.
+:ref:`separately <latexsphinxsetup>`.  It allows also local configurations
+inserted in generated files, via :rst:dir:`raw` directives.  For example, in
+the PDF documentation this chapter is styled especially, as will be described
+later.
 
 Keys that you may want to override include:
 
@@ -575,35 +583,48 @@ The colors used in the above are provided by the ``svgnames`` option of the
    }
 
 It is possible to insert further uses of the ``\sphinxsetup`` LaTeX macro
-directly into the body of the document, via the help of the :rst:dir:`raw`
+directly into the body of the document, via the help of the ``raw``
 directive. This chapter is styled in the PDF output using the following at the
-start of the chapter::
+start of the chapter (which uses keys described later in :ref:`additionalcss`)::
 
   .. raw:: latex
 
      \begingroup
      \sphinxsetup{%
-           % These were used as defaults for the whole sphinx.pdf
-           % VerbatimColor={RGB}{242,242,242},%
-           % VerbatimBorderColor={RGB}{32,32,32},%
-           % verbatimradius=3pt,%
-           % New definitions for this chapter code-blocks only:
-           VerbatimColor={named}{OldLace},
-           VerbatimBorderColor={named}{Gold},
-           verbatimradius=5pt,
-           verbatimsep=5pt,
-           verbatimborder=2pt,
-           % Other configuration for this chapter only:
-           TitleColor={named}{DarkGoldenrod},
-           hintBorderColor={named}{LightCoral},
-           attentionborder=3pt,
-           attentionBorderColor={named}{Crimson},
-           attentionBgColor={named}{FloralWhite},
-           noteborder=2pt,
-           noteBorderColor={named}{Olive},
-           cautionborder=3pt,
-           cautionBorderColor={named}{Cyan},
-           cautionBgColor={named}{LightCyan}}
+         TitleColor={named}{DarkGoldenrod},
+         % pre_border-width is 5.1.0 alias for verbatimborder
+         pre_border-width=2pt,
+         % pre_padding is 5.1.0 alias for verbatimsep
+         pre_padding=5pt,
+         % rounded boxes are new at 5.1.0
+         pre_border-radius=5pt,
+         % TeXcolor means syntax must be as for LaTeX \definecolor
+         pre_background-TeXcolor={named}{OldLace},
+         pre_border-TeXcolor={named}{Gold},
+         %
+         % 5.1.0 alias for warningborder
+         div.warning_border-width=3pt,
+         div.warning_padding=6pt,
+         div.warning_padding-right=18pt,
+         div.warning_padding-bottom=18pt,
+         div.warning_border-TeXcolor={named}{DarkCyan},
+         div.warning_background-TeXcolor={named}{LightCyan},
+         div.warning_box-shadow=-12pt -12pt inset,
+         div.warning_box-shadow-TeXcolor={named}{Cyan},
+         %
+         % 5.1.0 new name would be div.attention_border-width
+         attentionborder=3pt,
+         % same as div.attention_border-TeXcolor
+         attentionBorderColor={named}{Crimson},
+         % same as div.attention_background-TeXcolor
+         attentionBgColor={named}{FloralWhite},
+         %
+         % no CSS-like names yet at 5.1.0 for note-type admonitions
+         noteborder=2pt,
+         noteBorderColor={named}{Olive},
+         hintBorderColor={named}{LightCoral}%
+     }
+
 
 And this is placed at the end of the chapter source to end the scope of
 the configuration::
@@ -852,32 +873,6 @@ Do not use quotes to enclose values, whether numerical or strings.
 
     Default: ``\fboxrule``
 
-``verbatimradius``
-    The radius of the rounded corners of the frame around :rst:dir:`code-block`\ s.
-
-    Default: ``0pt``
-
-    .. versionadded:: 5.1.0
-
-       If non-zero, it will trigger the loading of LaTeX package pict2e_.
-
-       .. caution::
-
-          The interface will remain experimental during the 5.x cycle: the
-          feature itself will remain, but the interface may evolve to include
-          other display elements such as admonitions.  For the latter it is
-          actually already possible for LaTeX-expert Sphinx users to use
-          functionalities of LaTeX packages such as tcolorbox_, via
-          redefinitions of the ``sphinxheavybox`` and ``sphinxlightbox``
-          `Environments`_.  This would be more difficult for code-blocks, and
-          this key achieves it.  The pict2e_ interface to some basic PDF
-          graphics operations is much more light-weight than the pgf_
-          framework used by tcolorbox_.
-
-    .. _pict2e: https://ctan.org/pkg/pict2e
-    .. _tcolorbox: https://ctan.org/pkg/tcolorbox
-    .. _pgf: https://ctan.org/pkg/pgf
-
 ``shadowsep``
     The separation between contents and frame for :dudir:`contents` and
     :dudir:`topic` boxes.
@@ -894,20 +889,6 @@ Do not use quotes to enclose values, whether numerical or strings.
 
     Default: ``\fboxrule``
 
-``shadowBorderColor``
-    The color of the frame around :dudir:`topic` boxes.
-
-    Default: ``{rgb}{0,0,0}`` (black)
-
-    .. versionadded:: 5.1.0
-
-``shadowShadowColor``
-    The color of the lateral "shadow" to the right and bottom.
-
-    Default: ``{rgb}{0,0,0}`` (black)
-
-    .. versionadded:: 5.1.0
-
 |notebdcolors|
     The colour for the two horizontal rules used by Sphinx in LaTeX for styling
     a :dudir:`note` type admonition.
@@ -981,6 +962,236 @@ Do not use quotes to enclose values, whether numerical or strings.
                               ``attentionborder``, ``dangerborder``,
                               ``errorborder``
 
+.. _additionalcss:
+
+Additional  CSS-like ``'sphinxsetup'`` keys
+-------------------------------------------
+
+.. versionadded:: 5.1.0
+
+
+At ``5.1.0`` the LaTeX styling possibilities have been significantly enhanced.
+Code-blocks, topic directives, and the five warning-type directives each now
+possess:
+
+- four border-widths parameters,
+- four padding parameters,
+- four radius parameters (only circular arcs) for the corners,
+- optional shadow, with x-offset and y-offset being possibly negative,
+  and the shadow possibly inset,
+- colors for background, border and shadow.
+
+All those options have been named in a CSS-like way.  Indeed, in future it is
+envisioned to allow these settings to be specified either in an external file,
+or in a string variable which would be parsed to extract from CSS the
+selectors and properties which are understood.
+
+Currently though this is added via a bunch of new ``'sphinxsetup'`` keys
+whose names will be given now.
+
+.. important:: Low-level LaTeX errors causing a build failure can happen if
+   the input syntax is not respected.  In particular properties for colours,
+   whose names end with ``TeXcolor``, must be input as for the other colour
+   related options previously described, i.e. for example::
+
+     ...<other options>
+     div.warning_border-TeXcolor={rgb}{1,0,0},%
+     ...<other options>
+
+   A colon will not be accepted in place of the equal sign which is
+   expected by the LaTeX syntax.
+   Do not insert spaces in the input.  With the exception of the
+   ``box-shadow`` all dimensional parameters expect a unique dimension
+   not a space separated list of dimensions.
+
+Options for code-blocks:
+
+- | ``pre_border-top-width``,
+  | ``pre_border-right-width``,
+  | ``pre_border-bottom-width``,
+  | ``pre_border-left-width``,
+  | ``pre_border-width``, beware that this is a *single* dimension.  Its
+    default, and the ones of the separate widths is the setting of
+    ``\fboxrule`` in the preamble, i.e. normally ``0.4pt``.
+- ``pre_box-decoration-break`` can be set to ``clone`` or ``slice``, default
+  is ``clone`` for backwards compatibility.
+- | ``pre_padding-top``,
+  | ``pre_padding-right``,
+  | ``pre_padding-bottom``,
+  | ``pre_padding-left``,
+  | ``pre_padding``, again this is a single dimension.  Its default is the
+    setting of ``\fboxsep`` i.e. normally ``3pt``.
+- | ``pre_border-top-left-radius``,
+  | ``pre_border-top-right-radius``,
+  | ``pre_border-bottom-right-radius``,
+  | ``pre_border-bottom-left-radius``,
+  | ``pre_border-radius``, are all single dimensions (rounded corners are
+    circular arcs only), which default to ``0pt``.
+- ``pre_box-shadow`` is special in so far as it may be the ``none`` keyword,
+  or a single dimension
+  which will be assigned to both x-offset and y-offset, or two dimensions, or
+  two dimensions followed by the word ``inset``.  The x-offset and y-offset
+  may be negative.  The defaults is ``none``.
+- | ``pre_border-TeXcolor``,
+  | ``pre_background-TeXcolor``,
+  | ``pre_box-shadow-TeXcolor``.
+
+  They must all be of the format as accepted by LaTeX ``\definecolor``.  They
+  default to ``{rgb}{0,0,0}``, ``{rgb}{1,1,1}`` and ``{rgb}{0,0,0}``
+  respectively.
+
+If one of the radius parameters is positive, the separate border widths will
+be ignored and only the value set by ``pre_border-width`` will be used.  Also,
+if a shadow is present and is inset, the box will be rendered with straight
+corners.
+
+.. note::
+
+   Rounded boxes are done using the pict2e_ interface to some basic PDF
+   graphics operations.  If this LaTeX package can not be found the build will
+   proceed and render all boxes with straight corners.
+
+.. _pict2e: https://ctan.org/pkg/pict2e
+
+
+Options for topic boxes:
+
+- | ``div.topic_border-top-width``,
+  | ``div.topic_border-right-width``,
+  | ``div.topic_border-bottom-width``,
+  | ``div.topic_border-left-width``,
+  | ``div.topic_border-width``, beware that this is a *single* dimension.  Its
+    default, and the ones of the separate widths is the setting of
+    ``\fboxrule`` in the preamble, i.e. normally ``0.4pt``.
+- ``div.topic_box-decoration-break`` is currently ignored.
+- | ``div.topic_padding-top``,
+  | ``div.topic_padding-right``,
+  | ``div.topic_padding-bottom``,
+  | ``div.topic_padding-left``,
+  | ``div.topic_padding``,
+    again this is a single dimension.  Its default is ``5pt``.
+- | ``div.topic_border-top-left-radius``,
+  | ``div.topic_border-top-right-radius``,
+  | ``div.topic_border-bottom-right-radius``,
+  | ``div.topic_border-bottom-left-radius``,
+  | ``div.topic_border-radius``.
+
+  They all are single dimensions which default to ``0pt``.
+- ``div.topic_box-shadow`` defaults to ``4pt 4pt``.
+- | ``div.topic_border-TeXcolor``,
+  | ``div.topic_background-TeXcolor``,
+  | ``div.topic_box-shadow-TeXcolor``.
+
+  They  must all be of the format as accepted by
+  LaTeX ``\definecolor``.  They default to ``{rgb}{0,0,0}``, ``{rgb}{1,1,1}``
+  and ``{rgb}{0,0,0}`` respectively.
+
+Options for ``warning`` (and similarly for  ``caution``, ``attention``,
+``danger``, ``error``) directive:
+
+- | ``div.warning_border-top-width``,
+  | ``div.warning_border-right-width``,
+  | ``div.warning_border-bottom-width``,
+  | ``div.warning_border-left-width``,
+  | ``div.warning_border-width``,
+    beware that this is a *single* dimension.  Its
+    default, and the ones of the separate widths is ``1pt``.
+- ``div.warning_box-decoration-break`` is currently ignored.
+- | ``div.warning_padding-top``,
+  | ``div.warning_padding-right``,
+  | ``div.warning_padding-bottom``,
+  | ``div.warning_padding-left``,
+  | ``div.warning_padding``, again this is a single dimension.
+
+  .. important:: Prior to ``5.1.0`` there was no separate customizability of
+     padding for warning-type boxes in PDF via LaTeX output.  The sum of
+     padding and border-width (as set by ``warningborder``, now also named
+     ``div.warning_border-width``) was kept to a certain constant value (and
+     this limited the border-width to small values else the border could
+     overlap the text contents).  This behaviour is kept as default.  Using
+     the ``div.warning_padding`` key will cancel for all four paddings the
+     legacy behaviour, but using only one of the four padding keys leaves the
+     three other paddings behave as formerly.
+- | ``div.warning_border-top-left-radius``,
+  | ``div.warning_border-top-right-radius``,
+  | ``div.warning_border-bottom-right-radius``,
+  | ``div.warning_border-bottom-left-radius``,
+  | ``div.warning_border-radius``.
+
+  They are all single dimensions which default to ``0pt``.
+- ``div.warning_box-shadow`` defaults to ``none``.
+- | ``div.warning_border-TeXcolor``,
+  | ``div.warning_background-TeXcolor``,
+  | ``div.warning_box-shadow-TeXcolor``.
+
+  They  must all be of the format as accepted by
+  LaTeX ``\definecolor``.  They default to ``{rgb}{0,0,0}``, ``{rgb}{1,1,1}``
+  and ``{rgb}{0,0,0}`` respectively.
+
+In the above replace ``warning`` by one of ``caution``, ``attention``,
+``danger``, ``error`` to style the respective directives.
+
+The following legacy behaviour of the PDF layout is currently not
+customizable:
+
+- for code-blocks, padding and border-width and shadow (if one adds one) will
+  go into the margin; the code lines remain at the same place independently of
+  the values of the padding and border-width, except for being shifted
+  vertically of course to not overwrite other text.
+
+- for topic boxes and warning-type notices only the shadows will go into page
+  margin, the borders are kept within the text area.
+
+- ``contents`` and ``topic`` directive are styled the same way.
+
+.. note::
+
+   The ``note``-style admonition directives admit no such customization
+   interface at this stage.
+
+Here is a random example (not especially recommended!):
+
+.. code-block::
+
+   latex_elements = {
+       'sphinxsetup': """%
+   pre_background-TeXcolor={RGB}{242,242,242},% alias of VerbatimColor
+   pre_border-TeXcolor={RGB}{32,32,32},%
+   pre_box-decoration-break=slice,
+   % pre_border-top-width=5pt,% will be ignored due to non-zero radii
+   % pre_border-right-width=10pt,
+   % pre_border-bottom-width=15pt,
+   % pre_border-left-width=20pt,
+   pre_border-width=3pt,% sets equally the four border-widths,
+   %                      needed for rounded corners
+   pre_border-top-left-radius=20pt,
+   pre_border-top-right-radius=0pt,
+   pre_border-bottom-right-radius=20pt,
+   pre_border-bottom-left-radius=0pt,
+   pre_box-shadow=10pt 10pt,
+   pre_box-shadow-TeXcolor={RGB}{192,192,192},
+   %
+   div.topic_border-TeXcolor={RGB}{102,102,102},%
+   div.topic_box-shadow-TeXcolor={RGB}{187,187,187},%
+   div.topic_background-TeXcolor={RGB}{238,238,255},%
+   div.topic_border-bottom-right-radius=10pt,%
+   div.topic_border-top-right-radius=10pt,%
+   div.topic_border-width=2pt,%
+   div.topic_box-shadow=10pt 10pt,%
+   %
+   div.danger_border-width=10pt,%
+   div.danger_padding=6pt,% (see Important notice above)
+   div.danger_background-TeXcolor={rgb}{0.6,.8,0.8},%
+   div.danger_border-TeXcolor={RGB}{64,64,64},%
+   div.danger_box-shadow=-7pt 7pt,%
+   div.danger_box-shadow-TeXcolor={RGB}{192,192,192},%
+   div.danger_border-bottom-left-radius=15pt%
+   """,
+   }
+
+In future, it is hoped to add further CSS properties such as ``font`` or
+``color``.
+
 
 LaTeX macros and environments
 -----------------------------
diff --git a/sphinx/texinputs/sphinx.sty b/sphinx/texinputs/sphinx.sty
index 9b0b54c562..b1105515ba 100644
--- a/sphinx/texinputs/sphinx.sty
+++ b/sphinx/texinputs/sphinx.sty
@@ -47,6 +47,11 @@
 }{
     \RequirePackage{color}
 }
+% the \colorlet of xcolor (if at all loaded) is overkill for our use case
+\newcommand{\sphinxcolorlet}[2]
+    {\expandafter\let\csname\@backslashchar color@#1\expandafter\endcsname
+                     \csname\@backslashchar color@#2\endcsname }
+
 
 % Handle options via "kvoptions" (later loaded by hyperref anyhow)
 \RequirePackage{kvoptions}
@@ -72,36 +77,19 @@
 \AtBeginDocument{\define@key{sphinx}{bookmarksdepth}{\hypersetup{bookmarksdepth=#1}}}
 % \DeclareBoolOption[false]{usespart}% not used
 % dimensions, we declare the \dimen registers here.
-\newdimen\sphinxverbatimsep
+\newdimen\sphinxverbatimsep    % <-- TO BE REMOVED NOT USED ANYMORE AT 5.1.0
 \newdimen\sphinxverbatimborder
-\newdimen\sphinxverbatimradius
-\newdimen\sphinxshadowsep
-\newdimen\sphinxshadowsize
-\newdimen\sphinxshadowrule
+%
 % \DeclareStringOption is not convenient for the handling of these dimensions
 % because we want to assign the values to the corresponding registers. Even if
 % we added the code to the key handler it would be too late for the initial
 % set-up and we would need to do initial assignments explicitly. We end up
 % using \define@key directly.
 % verbatim
-\sphinxverbatimsep=\fboxsep
+\sphinxverbatimsep=\fboxsep    % <-- TO BE REMOVED NOT USED ANYMORE AT 5.1.0
   \define@key{sphinx}{verbatimsep}{\sphinxverbatimsep\dimexpr #1\relax}
 \sphinxverbatimborder=\fboxrule
   \define@key{sphinx}{verbatimborder}{\sphinxverbatimborder\dimexpr #1\relax}
-\sphinxverbatimradius=0pt
-  \define@key{sphinx}{verbatimradius}{%
-     \sphinxverbatimradius\dimexpr #1\relax
-     \ifdim\sphinxverbatimradius=\z@\else\RequirePackage{sphinxpackageboxes}\fi
-     }
-\AtBeginDocument{\define@key{sphinx}{verbatimradius}{\sphinxverbatimradius\dimexpr #1\relax}}
-% topic boxes
-\sphinxshadowsep =5pt
-  \define@key{sphinx}{shadowsep}{\sphinxshadowsep\dimexpr #1\relax}
-\sphinxshadowsize=4pt
-  \define@key{sphinx}{shadowsize}{\sphinxshadowsize\dimexpr #1\relax}
-\sphinxshadowrule=\fboxrule
-  \define@key{sphinx}{shadowrule}{\sphinxshadowrule\dimexpr #1\relax}
-% verbatim
 \DeclareBoolOption[true]{verbatimwithframe}
 \DeclareBoolOption[true]{verbatimwrapslines}
 \DeclareBoolOption[false]{verbatimforcewraps}
@@ -119,6 +107,17 @@
 \DeclareStringOption % must use braces to hide the brackets
   [{\makebox[2\fontcharwd\font`\x][r]{\textcolor{red}{\tiny$\m@th\hookrightarrow$}}}]%
   {verbatimcontinued}
+% topic boxes
+% alternative names and definitions in 5.1.0 section below
+\newdimen\sphinxshadowsep  % <-- TO BE REMOVED NOT USED ANYMORE AT 5.1.0
+\newdimen\sphinxshadowsize % <-- TO BE REMOVED NOT USED ANYMORE AT 5.1.0
+\newdimen\sphinxshadowrule
+\sphinxshadowsep=5pt
+  \define@key{sphinx}{shadowsep}{\sphinxshadowsep\dimexpr #1\relax}%
+\sphinxshadowsize=4pt
+  \define@key{sphinx}{shadowsize}{\sphinxshadowsize\dimexpr #1\relax}
+\sphinxshadowrule=\fboxrule % catches current value (probably 0.4pt)
+  \define@key{sphinx}{shadowrule}{\sphinxshadowrule\dimexpr #1\relax}
 % notices/admonitions
 % the dimensions for notices/admonitions are kept as macros and assigned to
 % \spx@notice@border at time of use, hence \DeclareStringOption is ok for this
@@ -161,9 +160,6 @@
 }%
 % Default color chosen to be as in minted.sty LaTeX package!
 \sphinxDeclareSphinxColorOption{VerbatimHighlightColor}{{rgb}{0.878,1,1}}
-% topic and contents boxes
-\sphinxDeclareSphinxColorOption{shadowBorderColor}{{rgb}{0,0,0}}
-\sphinxDeclareSphinxColorOption{shadowShadowColor}{{rgb}{0,0,0}}
 % admonition boxes, "light" style
 \sphinxDeclareSphinxColorOption{noteBorderColor}{{rgb}{0,0,0}}
 \sphinxDeclareSphinxColorOption{hintBorderColor}{{rgb}{0,0,0}}
@@ -180,6 +176,416 @@
 \sphinxDeclareSphinxColorOption{attentionBgColor}{{rgb}{1,1,1}}
 \sphinxDeclareSphinxColorOption{dangerBgColor}{{rgb}{1,1,1}}
 \sphinxDeclareSphinxColorOption{errorBgColor}{{rgb}{1,1,1}}
+%%%%%%%%
+%
+% Additions at 5.1.0
+%
+% In future, an alternative user interface will perhaps be provided via
+% CSS-like input in a configuration variable latex_css, and Sphinx
+% will then parse it into the \sphinxsetup options described it. 
+%
+% In the meantime we adopt already some CSS-like names.  However,
+% attention to not use these options as genuine CSS properties, only
+% very limited syntax is supported.
+%
+\def\spxstring@none{none}
+\def\spxstring@clone{clone}
+% Future: should below all the macros holding dimensions be defined via some
+% \edef and \dimexpr rather?
+%
+% Deliberately the code avoids creating (except by \let) new \dimen variables
+% besides the legacy ones already defined.
+%
+% code-blocks
+\let\spxdimen@pre@border\sphinxverbatimborder
+\define@key{sphinx}{pre_border-top-width}{\def\spx@pre@border@top{#1}}
+\define@key{sphinx}{pre_border-right-width}{\def\spx@pre@border@right{#1}}
+\define@key{sphinx}{pre_border-bottom-width}{\def\spx@pre@border@bottom{#1}}
+\define@key{sphinx}{pre_border-left-width}{\def\spx@pre@border@left{#1}}
+% currently accepts only one dimension specification
+\define@key{sphinx}{pre_border-width}{%
+   \spxdimen@pre@border\dimexpr #1\relax
+   \def\spx@pre@border@top  {\spxdimen@pre@border}%
+   \let\spx@pre@border@right \spx@pre@border@top
+   \let\spx@pre@border@bottom\spx@pre@border@top
+   \let\spx@pre@border@left  \spx@pre@border@top
+}
+\def\spx@pre@border@top  {\spxdimen@pre@border}%
+\let\spx@pre@border@right \spx@pre@border@top
+\let\spx@pre@border@bottom\spx@pre@border@top
+\let\spx@pre@border@left  \spx@pre@border@top
+\expandafter\let\expandafter\KV@sphinx@verbatimborder
+                            \csname KV@sphinx@pre_border-width\endcsname
+\newif\ifspx@pre@border@open % defaults to false (at least for 5.x series)
+\define@key{sphinx}{pre_box-decoration-break}%
+           {\begingroup\edef\spx@tempa{#1}\expandafter\endgroup
+            \ifx\spx@tempa\spxstring@clone
+                 \spx@pre@border@openfalse
+            \else\spx@pre@border@opentrue\fi}
+%
+% MEMO: \sphinxverbatimsep not used anywhere anymore in the code, to be removed
+\define@key{sphinx}{pre_padding-top}{\def\spx@pre@padding@top{#1}}
+\define@key{sphinx}{pre_padding-right}{\def\spx@pre@padding@right{#1}}
+\define@key{sphinx}{pre_padding-bottom}{\def\spx@pre@padding@bottom{#1}}
+\define@key{sphinx}{pre_padding-left}{\def\spx@pre@padding@left{#1}}
+\define@key{sphinx}{pre_padding}{%
+   \def\spx@pre@padding@top   {#1}% use some pre \dimexpr expansion?
+   \let\spx@pre@padding@right \spx@pre@padding@top
+   \let\spx@pre@padding@bottom\spx@pre@padding@top
+   \let\spx@pre@padding@left  \spx@pre@padding@top
+}
+\edef\spx@pre@padding@top {\number\fboxsep sp}% \sphinxverbatimsep to be removed
+\let\spx@pre@padding@right \spx@pre@padding@top
+\let\spx@pre@padding@bottom\spx@pre@padding@top
+\let\spx@pre@padding@left  \spx@pre@padding@top
+\expandafter\let\expandafter\KV@sphinx@verbatimsep
+                            \csname KV@sphinx@pre_padding\endcsname
+%
+% We do not define a new \dimen (in 5.x pre-5.1.0 dev branch there
+% was a \sphinxverbatimradius when rounded boxes were first introduced,
+% but we removed it).
+\define@key{sphinx}{pre_border-top-left-radius}{\def\spx@pre@radius@topleft{#1}}
+\define@key{sphinx}{pre_border-top-right-radius}{\edef\spx@pre@radius@topright{#1}}
+\define@key{sphinx}{pre_border-bottom-right-radius}{\def\spx@pre@radius@bottomright{#1}}
+\define@key{sphinx}{pre_border-bottom-left-radius}{\def\spx@pre@radius@bottomleft{#1}}
+\define@key{sphinx}{pre_border-radius}{%
+   \def\spx@pre@radius@topleft    {#1}%
+   \let\spx@pre@radius@topright   \spx@pre@radius@topleft
+   \let\spx@pre@radius@bottomright\spx@pre@radius@topleft
+   \let\spx@pre@radius@bottomleft \spx@pre@radius@topleft
+}
+% MEMO: keep in mind in using these macros in code elsewhere that they can
+% thus be dimen registers or simply dimensional specs such as 3pt
+\let\spx@pre@radius@topleft    \z@
+\let\spx@pre@radius@topright   \z@
+\let\spx@pre@radius@bottomright\z@
+\let\spx@pre@radius@bottomleft \z@
+\AtBeginDocument{\if1\ifdim\spx@pre@radius@topleft>\z@0\fi
+                     \ifdim\spx@pre@radius@topright>\z@0\fi
+                     \ifdim\spx@pre@radius@bottomright>\z@0\fi
+                     \ifdim\spx@pre@radius@bottomleft>\z@0\fi
+                    1\else\spx@RequirePackage@PictIIe\fi}
+%
+\newif\ifspx@pre@withshadow
+\newif\ifspx@pre@insetshadow
+% Attention only "none" or "<xoffset> <yoffset> [optional inset]", no color
+\define@key{sphinx}{pre_box-shadow}{\spx@pre@box@shadow@setter #1 {} {} \@nnil}%
+% TODO add parsing to fetch color... but this requires a TeX layer to convert
+% color spec in CSS format to color/xcolor format
+\def\spx@pre@box@shadow@setter #1 #2 #3 #4\@nnil{%
+  \begingroup\edef\spx@tempa{#1}\expandafter\endgroup
+  \ifx\spx@tempa\spxstring@none
+      \spx@pre@withshadowfalse
+  \else
+    \spx@pre@withshadowtrue
+    \edef\spx@pre@shadow@xoffset{\number\dimexpr#1\relax sp}%
+    \edef\spx@pre@shadow@yoffset{\number\dimexpr#2+\z@\relax sp}%
+    \if\relax\detokenize{#3}\relax
+      \spx@pre@insetshadowfalse
+    \else
+      \spx@pre@insetshadowtrue
+    \fi
+  \fi     
+}%
+\spx@pre@box@shadow@setter none {} {} \@nnil
+%
+\newif\ifspx@pre@withbordercolor
+\define@key{sphinx}{pre_border-TeXcolor}{%
+    \spx@pre@withbordercolortrue
+    \definecolor{VerbatimBorderColor}#1% legacy colour name with no sphinx prefix
+}
+\expandafter\let\expandafter\KV@sphinx@VerbatimBorderColor
+                            \csname KV@sphinx@pre_border-TeXcolor\endcsname
+\newif\ifspx@pre@withbackgroundcolor
+\define@key{sphinx}{pre_background-TeXcolor}{%
+    \spx@pre@withbackgroundcolortrue
+    \definecolor{VerbatimColor}#1% legacy colour name with no sphinx prefix
+}
+\expandafter\let\expandafter\KV@sphinx@VerbatimColor
+                            \csname KV@sphinx@pre_background-TeXcolor\endcsname
+\newif\ifspx@pre@withshadowcolor
+\define@key{sphinx}{pre_box-shadow-TeXcolor}{%
+    \spx@pre@withshadowcolortrue
+    \definecolor{sphinxVerbatimShadowColor}#1%
+}
+\definecolor{sphinxVerbatimShadowColor}{rgb}{0,0,0}
+% topics
+\let\spxdimen@topic@border\sphinxshadowrule
+\define@key{sphinx}{div.topic_border-top-width}{\def\spx@topic@border@top{#1}}
+\define@key{sphinx}{div.topic_border-right-width}{\def\spx@topic@border@right{#1}}
+\define@key{sphinx}{div.topic_border-bottom-width}{\def\spx@topic@border@bottom{#1}}
+\define@key{sphinx}{div.topic_border-left-width}{\def\spx@topic@border@left{#1}}
+% attention currently accepts only one dimension specification
+\define@key{sphinx}{div.topic_border-width}{%
+   \spxdimen@topic@border\dimexpr #1\relax
+   \def\spx@topic@border@top  {\spxdimen@topic@border}%
+   \let\spx@topic@border@right \spx@topic@border@top
+   \let\spx@topic@border@bottom\spx@topic@border@top
+   \let\spx@topic@border@left  \spx@topic@border@top
+}
+\let\spx@topic@border@top   \spxdimen@topic@border
+\let\spx@topic@border@right \spx@topic@border@top
+\let\spx@topic@border@bottom\spx@topic@border@top
+\let\spx@topic@border@left  \spx@topic@border@top
+\expandafter\let\expandafter\KV@sphinx@shadowrule
+                            \csname KV@sphinx@topic_border-width\endcsname
+\newif\ifspx@topic@border@open % defaults to false (legacy)
+\define@key{sphinx}{div.topic_box-decoration-break}%
+           {\begingroup\edef\spx@tempa{#1}\expandafter\endgroup
+            \ifx\spx@tempa\spxstring@clone
+                 \spx@topic@border@openfalse
+            \else\spx@topic@border@opentrue\fi}%
+%
+% MEMO: \sphinxshadowsep not used anywhere anymore in code base and to be removed
+\define@key{sphinx}{topic_padding-top}{\def\spx@topic@padding@top{#1}}
+\define@key{sphinx}{topic_padding-right}{\def\spx@topic@padding@right{#1}}
+\define@key{sphinx}{topic_padding-bottom}{\def\spx@topic@padding@bottom{#1}}
+\define@key{sphinx}{topic_padding-left}{\def\spx@topic@padding@left{#1}}
+\define@key{sphinx}{topic_padding}{%
+   \def\spx@topic@padding@top   {#1}%
+   \let\spx@topic@padding@right \spx@topic@padding@top
+   \let\spx@topic@padding@bottom\spx@topic@padding@top
+   \let\spx@topic@padding@left  \spx@topic@padding@top
+}
+\def\spx@topic@padding@top   {5pt}% no usage anymore of \sphinxshadowsep dimen register
+\let\spx@topic@padding@right \spx@topic@padding@top
+\let\spx@topic@padding@bottom\spx@topic@padding@top
+\let\spx@topic@padding@left  \spx@topic@padding@top
+\expandafter\let\expandafter\KV@sphinx@shadowsep
+                            \csname KV@sphinx@topic_padding\endcsname
+%
+\define@key{sphinx}{div.topic_border-top-left-radius}{\def\spx@topic@radius@topleft{#1}}
+\define@key{sphinx}{div.topic_border-top-right-radius}{\def\spx@topic@radius@topright{#1}}
+\define@key{sphinx}{div.topic_border-bottom-right-radius}{\def\spx@topic@radius@bottomright{#1}}
+\define@key{sphinx}{div.topic_border-bottom-left-radius}{\def\spx@topic@radius@bottomleft{#1}}
+\define@key{sphinx}{div.topic_border-radius}{%
+   \def\spx@topic@radius@topleft    {#1}%
+   \let\spx@topic@radius@topright   \spx@topic@radius@topleft
+   \let\spx@topic@radius@bottomright\spx@topic@radius@topleft
+   \let\spx@topic@radius@bottomleft \spx@topic@radius@topleft
+}
+\let\spx@topic@radius@topleft    \z@
+\let\spx@topic@radius@topright   \z@
+\let\spx@topic@radius@bottomright\z@
+\let\spx@topic@radius@bottomleft \z@
+\AtBeginDocument{\if1\ifdim\spx@topic@radius@topleft>\z@0\fi
+                     \ifdim\spx@topic@radius@topright>\z@0\fi
+                     \ifdim\spx@topic@radius@bottomright>\z@0\fi
+                     \ifdim\spx@topic@radius@bottomleft>\z@0\fi
+                    1\else\spx@RequirePackage@PictIIe\fi}
+%
+\newif\ifspx@topic@withshadow
+\newif\ifspx@topic@insetshadow
+% Attention only "none" or "<xoffset> <yoffset> [optional inset]", no color
+\define@key{sphinx}{div.topic_box-shadow}{\spx@topic@box@shadow@setter #1 {} {} \@nnil}%
+\def\spx@topic@box@shadow@setter #1 #2 #3 #4\@nnil{%
+  \begingroup\edef\spx@tempa{#1}\expandafter\endgroup
+  \ifx\spx@tempa\spxstring@none
+      \spx@topic@withshadowfalse
+  \else
+    \spx@topic@withshadowtrue
+    \edef\spx@topic@shadow@xoffset{\number\dimexpr#1\relax sp}%
+    \edef\spx@topic@shadow@yoffset{\number\dimexpr#2+\z@\relax sp}%
+    \if\relax\detokenize{#3}\relax
+      \spx@topic@insetshadowfalse
+    \else
+      \spx@topic@insetshadowtrue
+    \fi
+  \fi     
+}%
+\spx@topic@box@shadow@setter 4pt 4pt {} \@nnil
+% Suport for legacy shadowsize, the \sphinxshadowsize \dimen register
+% is not used anymore and should not even be allocated in future
+\define@key{sphinx}{shadowsize}{%
+  \edef\spx@topic@shadow@xoffset{\number\dimexpr#1\relax sp}%
+  \let\spx@topic@shadow@yoffset\spx@topic@shadow@xoffset
+  \ifdim\spx@topic@shadow@xoffset=\z@
+      \spx@topic@box@withshadowtrue
+  \else
+      \spx@topic@box@withshadowfalse
+      \spx@topic@box@shadow@insetfalse
+  \fi
+}%
+\definecolor{sphinxTopicBorderColor}{rgb}{0,0,0}
+\definecolor{sphinxTopicBackgroundColor}{rgb}{1,1,1}
+\definecolor{sphinxTopicShadowColor}{rgb}{0,0,0}
+\newif\ifspx@topic@withbordercolor
+\define@key{sphinx}{div.topic_border-TeXcolor}{%
+    \spx@topic@withbordercolortrue
+    \definecolor{sphinxTopicBorderColor}#1%
+}
+\newif\ifspx@topic@withbackgroundcolor
+\define@key{sphinx}{div.topic_background-TeXcolor}{%
+    \spx@topic@withbackgroundcolortrue
+    \definecolor{sphinxTopicBackgroundColor}#1%
+}
+\newif\ifspx@topic@withshadowcolor
+\define@key{sphinx}{div.topic_box-shadow-TeXcolor}{%
+    \spx@topic@withshadowcolortrue
+    \definecolor{sphinxTopicShadowColor}#1%
+}
+% warning, caution, attention, danger, error
+\def\spx@tempa#1{%
+  \expandafter\spx@tempb
+% MEMO: the diverging naming of first one is conditioned at this time by the fact 
+% that sphinxnotice environment must work both for these admonitions and the
+% note, tip etc... ones
+  \csname spx@opt@#1border\expandafter\endcsname
+  \csname spx@#1@border@top\expandafter\endcsname
+  \csname spx@#1@border@right\expandafter\endcsname
+  \csname spx@#1@border@bottom\expandafter\endcsname
+  \csname spx@#1@border@left\expandafter\endcsname
+  \csname ifspx@#1@border@open\expandafter\endcsname
+  \csname spx@#1@border@opentrue\expandafter\endcsname
+  \csname spx@#1@border@openfalse\endcsname
+  {#1}%
+}%
+\def\spx@tempb #1#2#3#4#5#6#7#8#9{%
+  \define@key{sphinx}{div.#9_border-top-width}{\def#2{##1}}%
+  \define@key{sphinx}{div.#9_border-right-width}{\def#3{##1}}%
+  \define@key{sphinx}{div.#9_border-bottom-width}{\def#4{##1}}%
+  \define@key{sphinx}{div.#9_border-left-width}{\def#5{##1}}%
+  \define@key{sphinx}{div.#9_border-width}{\def#1{##1}\def#2{#1}\let#3#2\let#4#2\let#5#2}%
+  \def#1{1pt}\let#2#1\let#3#2\let#4#2\let#5#2%
+  \newif#6%
+  \define@key{sphinx}{div.#9_box-decoration-break}%
+           {\begingroup\edef\spx@tempa{##1}\expandafter\endgroup
+            \ifx\spx@tempa\spxstring@clone#8\else#7\fi}%
+  \expandafter\let\csname KV@sphinx@#9border\expandafter\endcsname
+                  \csname KV@sphinx@div.#9_border-width\endcsname
+}
+\spx@tempa{warning}
+\spx@tempa{caution}
+\spx@tempa{attention}
+\spx@tempa{danger}
+\spx@tempa{error}
+
+\def\spx@tempa#1{%
+  \expandafter\spx@tempb
+  \csname spx@#1@padding\expandafter\endcsname
+  \csname spx@#1@padding@top\expandafter\endcsname
+  \csname spx@#1@padding@right\expandafter\endcsname
+  \csname spx@#1@padding@bottom\expandafter\endcsname
+  \csname spx@#1@padding@left\expandafter\endcsname
+% MEMO: this is to keep same behaviour as prior to 5.1.0 for which
+% no key to set padding adjusted and border+padding was kept constant
+  \csname spx@opt@#1border\endcsname
+  {#1}%
+}%
+\def\spx@tempb #1#2#3#4#5#6#7{%
+  \define@key{sphinx}{div.#7_padding-top}{\def#2{##1}}%
+  \define@key{sphinx}{div.#7_padding-right}{\def#3{##1}}%
+  \define@key{sphinx}{div.#7_padding-bottom}{\def#4{##1}}%
+  \define@key{sphinx}{div.#7_padding-left}{\def#5{##1}}%
+  \define@key{sphinx}{div.#7_padding}{\def#1{##1}\def#2{#1}\let#3#2\let#4#2\let#5#2}%
+% MEMO: prior to 5.1.0 padding was not separately customizable
+% This keeps exactly the strange behaviour as prior to 5.1.0
+% which used to be hard-coded in the sphinxheavybox environment
+  \def#1{\dimexpr.6\baselineskip-#6\relax}%
+  \let#2#1\let#3#2\let#4#2\let#5#2%
+}
+\spx@tempa{warning}
+\spx@tempa{caution}
+\spx@tempa{attention}
+\spx@tempa{danger}
+\spx@tempa{error}
+
+\def\spx@tempa#1{%
+  \expandafter\spx@tempb
+  \csname spx@#1@radius@topleft\expandafter\endcsname
+  \csname spx@#1@radius@topright\expandafter\endcsname
+  \csname spx@#1@radius@bottomright\expandafter\endcsname
+  \csname spx@#1@radius@bottomleft\endcsname
+  {#1}%
+}%
+\def\spx@tempb #1#2#3#4#5{%
+  \define@key{sphinx}{div.#5_border-top-left-radius}{\def#1{##1}}%
+  \define@key{sphinx}{div.#5_border-top-right-radius}{\def#2{##1}}%
+  \define@key{sphinx}{div.#5_border-bottom-right-radius}{\def#3{##1}}%
+  \define@key{sphinx}{div.#5_border-bottom-left-radius}{\def#4{##1}}%
+  \define@key{sphinx}{div.#5_border-radius}{\def#1{##1}\let#2#1\let#3#1\let#4#1}%
+  \let#1\z@\let#2#1\let#3#2\let#4#2%
+  \AtBeginDocument{\if1\ifdim#1>\z@0\fi
+    \ifdim#2>\z@0\fi
+    \ifdim#3>\z@0\fi
+    \ifdim#4>\z@0\fi
+    1\else\spx@RequirePackage@PictIIe\fi}%
+}
+\spx@tempa{warning}
+\spx@tempa{caution}
+\spx@tempa{attention}
+\spx@tempa{danger}
+\spx@tempa{error}
+
+\def\spx@tempa#1{%
+  \expandafter\spx@tempb
+  \csname ifspx@#1@withshadow\expandafter\endcsname
+  \csname ifspx@#1@insetshadow\expandafter\endcsname
+  \csname ifspx@#1@withshadowcolor\expandafter\endcsname
+  \csname ifspx@#1@withbordercolor\expandafter\endcsname
+  \csname ifspx@#1@withbackgroundcolor\endcsname
+}%
+\def\spx@tempb#1#2#3#4#5{\newif#1\newif#2\newif#3\newif#4\newif#5}%
+\spx@tempa{warning}
+\spx@tempa{caution}
+\spx@tempa{attention}
+\spx@tempa{danger}
+\spx@tempa{error}
+
+\def\spx@tempa#1{%
+  \expandafter\spx@tempb
+  \csname spx@#1@withshadowtrue\expandafter\endcsname
+  \csname spx@#1@withshadowfalse\expandafter\endcsname
+  \csname spx@#1@insetshadowtrue\expandafter\endcsname
+  \csname spx@#1@insetshadowfalse\expandafter\endcsname
+  \csname spx@#1@box@shadow@setter\expandafter\endcsname
+  \csname spx@#1@box@shadow@xoffset\expandafter\endcsname
+  \csname spx@#1@box@shadow@yoffset\endcsname
+  {#1}%
+}%
+\def\spx@tempb#1#2#3#4#5#6#7#8{%
+  \define@key{sphinx}{div.#8_box-shadow}{#5##1 {} {} \@nnil}%
+  \def#5##1 ##2 ##3 ##4\@nnil{%
+  \begingroup\edef\spx@tempa{##1}\expandafter\endgroup
+  \ifx\spx@tempa\spxstring@none
+        #2%
+  \else #1\edef#6{\number\dimexpr##1\relax sp}%
+          \edef#7{\number\dimexpr##2+\z@\relax sp}%
+    \if\relax\detokenize{##3}\relax#4\else#3\fi
+  \fi     
+  }#5none {} {} \@nnil
+}
+\spx@tempa{warning}
+\spx@tempa{caution}
+\spx@tempa{attention}
+\spx@tempa{danger}
+\spx@tempa{error}
+
+\def\spx@tempa#1{%
+  \expandafter\spx@tempb
+  \csname spx@#1@withbordercolortrue\expandafter\endcsname
+  \csname spx@#1@withbackgroundcolortrue\expandafter\endcsname
+  \csname spx@#1@withshadowcolortrue\endcsname
+  {#1}%
+}
+\def\spx@tempb#1#2#3#4{%
+  \definecolor{sphinx#4BorderColor}{rgb}{0,0,0}%
+  \definecolor{sphinx#4BgColor}{rgb}{1,1,1}%
+  \definecolor{sphinx#4ShadowColor}{rgb}{0,0,0}%
+  \define@key{sphinx}{div.#4_border-TeXcolor}{#1\definecolor{sphinx#4BorderColor}##1}%
+  \define@key{sphinx}{div.#4_background-TeXcolor}{#2\definecolor{sphinx#4BgColor}##1}%
+  \define@key{sphinx}{div.#4_box-shadow-TeXcolor}{#3\definecolor{sphinx#4ShadowColor}##1}%
+  \expandafter\let\csname KV@sphinx@#4BorderColor\expandafter\endcsname
+                  \csname KV@sphinx@div.#4_border-TeXcolor\endcsname
+  \expandafter\let\csname KV@sphinx@#4BgColor\expandafter\endcsname
+                  \csname KV@sphinx@div.#4_background-TeXcolor\endcsname
+}
+\spx@tempa{warning}
+\spx@tempa{caution}
+\spx@tempa{attention}
+\spx@tempa{danger}
+\spx@tempa{error}
+
 
 \DeclareDefaultOption{\@unknownoptionerror}
 \ProcessKeyvalOptions*
@@ -278,12 +684,10 @@
 
 %% FRAMED ENVIRONMENTS
 %
+\RequirePackage{sphinxpackageboxes}
 \input{sphinxlatexadmonitions.sty}
 \input{sphinxlatexliterals.sty}
 \input{sphinxlatexshadowbox.sty}
-\ifdim\sphinxverbatimradius=\z@\else
-  \RequirePackage{sphinxpackageboxes}
-\fi
 
 
 %% CONTAINERS
diff --git a/sphinx/texinputs/sphinxlatexadmonitions.sty b/sphinx/texinputs/sphinxlatexadmonitions.sty
index b261ad7f67..052de9bb0b 100644
--- a/sphinx/texinputs/sphinxlatexadmonitions.sty
+++ b/sphinx/texinputs/sphinxlatexadmonitions.sty
@@ -16,6 +16,7 @@
 %   settings, cf sphinx docs (latex customization).
 %
 % Requires:
+\RequirePackage{sphinxpackageboxes}
 \RequirePackage{framed}% used by sphinxheavybox
 %
 % Dependencies (they do not need to be defined at time of loading):
@@ -65,24 +66,116 @@
 \definecolor{sphinxtipBgColor}{rgb}{1,1,1}
 
 % Others get more distinction
+\def\spx@admonitions@boxes@fcolorbox@setup{%
+  \spx@boxes@border@top   \@nameuse{spx@\spx@noticetype @border@top}%
+  \spx@boxes@border@right \@nameuse{spx@\spx@noticetype @border@right}%
+  \spx@boxes@border@bottom\@nameuse{spx@\spx@noticetype @border@bottom}%
+  \spx@boxes@border@left  \@nameuse{spx@\spx@noticetype @border@left}%
+  \spx@boxes@border       \spx@notice@border
+%
+  \spx@boxes@padding@top   \@nameuse{spx@\spx@noticetype @padding@top}%
+  \spx@boxes@padding@right \@nameuse{spx@\spx@noticetype @padding@right}%
+  \spx@boxes@padding@bottom\@nameuse{spx@\spx@noticetype @padding@bottom}%
+  \spx@boxes@padding@left  \@nameuse{spx@\spx@noticetype @padding@left}%
+%
+  \spx@boxes@radius@topleft     \@nameuse{spx@\spx@noticetype @radius@topleft}%
+  \spx@boxes@radius@topright    \@nameuse{spx@\spx@noticetype @radius@topright}%
+  \spx@boxes@radius@bottomright \@nameuse{spx@\spx@noticetype @radius@bottomright}%
+  \spx@boxes@radius@bottomleft  \@nameuse{spx@\spx@noticetype @radius@bottomleft}%
+  \relax
+  \iftrue\@nameuse{ifspx@\spx@noticetype @withshadow}%
+     \spx@boxes@withshadowtrue
+     \spx@boxes@shadow@xoffset \@nameuse{spx@\spx@noticetype @box@shadow@xoffset}%
+     \spx@boxes@shadow@yoffset \@nameuse{spx@\spx@noticetype @box@shadow@yoffset}\relax
+  \else
+     \spx@boxes@withshadowfalse
+  \fi\@nameuse{fi}%
+  \iftrue\@nameuse{ifspx@\spx@noticetype @insetshadow}%
+     \spx@boxes@insetshadowtrue
+  \else
+     \spx@boxes@insetshadowfalse
+  \fi\@nameuse{fi}%
+  \iftrue\@nameuse{ifspx@\spx@noticetype @withshadowcolor}%
+    \spx@boxes@withshadowcolortrue
+  \else
+    \spx@boxes@withshadowcolorfalse
+  \fi\@nameuse{fi}%
+  %
+  \iftrue\@nameuse{ifspx@\spx@noticetype @withbackgroundcolor}%
+    \spx@boxes@withbackgroundcolortrue
+  \else
+    \spx@boxes@withbackgroundcolorfalse
+  \fi\@nameuse{fi}%
+  \sphinxcolorlet{spx@boxes@backgroundcolor}{spx@notice@bgcolor}%
+  %
+  \iftrue\@nameuse{ifspx@\spx@noticetype @withbordercolor}%
+    \spx@boxes@withbordercolortrue
+  \else
+    \spx@boxes@withbordercolorfalse
+  \fi\@nameuse{fi}%
+  \sphinxcolorlet{spx@boxes@bordercolor}{spx@notice@bordercolor}%
+  %
+  \iftrue\@nameuse{ifspx@\spx@noticetype @withshadowcolor}%
+    \spx@boxes@withshadowcolortrue
+  \else
+    \spx@boxes@withshadowcolorfalse
+  \fi\@nameuse{fi}%
+  \sphinxcolorlet{spx@boxes@shadowcolor}{sphinx\spx@noticetype ShadowColor}%
+}
 % Code adapted from framed.sty's "snugshade" environment.
 % Nesting works (inner frames do not allow page breaks).
 \newenvironment{sphinxheavybox}{\par
-   \setlength{\FrameRule}{\spx@notice@border}%
-   \setlength{\FrameSep}{\dimexpr.6\baselineskip-\FrameRule\relax}
+   \spx@admonitions@boxes@fcolorbox@setup
+   % Those are used by sphinxVerbatim if the \ifspx@inframed boolean is true
+   \setlength{\FrameRule}{0.5\dimexpr\spx@boxes@border@top+\spx@boxes@border@bottom\relax}%
+   % MEMO: prior to 5.1.0 \FrameSep was determined as 0.6\baselineskip -
+   % \FrameRule, and there was no possibility for user to adjust padding.
+   % Then \fcolorbox was used with \fboxrule set to \FrameRule and \fboxsep
+   % set to \FrameSep.
+   % The 5.1.0 default calculation of padding parameters maintains PDF output
+   % identical to legacy behaviour, as long as padding is not set by user.
+   \setlength{\FrameSep}{0.5\dimexpr\spx@boxes@padding@top+\spx@boxes@padding@bottom\relax}%
    \advance\spx@image@maxheight
-   -\dimexpr2\FrameRule
-           +2\FrameSep
+   -\dimexpr\spx@boxes@border@top+\spx@boxes@border@bottom
+           +\spx@boxes@padding@top+\spx@boxes@padding@bottom
            +\baselineskip\relax % will happen again if nested, needed indeed!
+   % MEMO: the next comment is before boxing was extended to allow padding and
+   % multiple border-widths, not to mention shadows...
    % configure framed.sty's parameters to obtain same vertical spacing
    % as for "light" boxes. We need for this to manually insert parskip glue and
    % revert a skip done by framed before the frame.
     \ltx@ifundefined{OuterFrameSep}{}{\OuterFrameSep\z@skip}%
     \vspace{\FrameHeightAdjust}
    % copied/adapted from framed.sty's snugshade
+   % but now using in place of \fcolorbox the Sphinx sophisticated own
    \def\FrameCommand##1{\hskip\@totalleftmargin
-       \fboxsep\FrameSep \fboxrule\FrameRule
-       \fcolorbox{spx@notice@bordercolor}{spx@notice@bgcolor}{##1}%
+  \ifspx@boxes@withshadow
+   \ifspx@boxes@insetshadow\else
+    \ifdim\spx@boxes@shadow@xoffset<\z@\hskip\spx@boxes@shadow@xoffset\relax
+    \fi
+   \fi
+  \fi
+        \if1% use rounded boxes only if needed and possible
+          \ifdim\spx@boxes@radius@topleft    >\z@0\fi
+          \ifdim\spx@boxes@radius@topright   >\z@0\fi
+          \ifdim\spx@boxes@radius@bottomright>\z@0\fi
+          \ifdim\spx@boxes@radius@bottomleft >\z@0\fi
+          1\spx@boxes@fcolorbox{##1}%
+        \else
+          \@ifpackageloaded{pict2e}%
+             {\ifspx@boxes@insetshadow
+                \spx@boxes@fcolorbox{##1}%
+              \else
+                \spx@boxes@fcolorbox@rounded{##1}%
+              \fi}%
+             {\spx@boxes@fcolorbox{##1}}%
+        \fi
+  \ifspx@boxes@withshadow
+   \ifspx@boxes@insetshadow\else
+    \ifdim\spx@boxes@shadow@xoffset>\z@\hskip-\spx@boxes@shadow@xoffset\relax
+    \fi
+   \fi
+  \fi
        \hskip-\linewidth \hskip-\@totalleftmargin \hskip\columnwidth}%
    \savenotes
    % use a minipage if we are already inside a framed environment
@@ -129,11 +222,6 @@
   {\begin{sphinxheavybox}\sphinxstrong{#1} }{\end{sphinxheavybox}}
 % or just use package options
 
-% the \colorlet of xcolor (if at all loaded) is overkill for our use case
-\newcommand{\sphinxcolorlet}[2]
-    {\expandafter\let\csname\@backslashchar color@#1\expandafter\endcsname
-                     \csname\@backslashchar color@#2\endcsname }
-
 % the main dispatch for all types of notices
 \newenvironment{sphinxadmonition}[2]{% #1=type, #2=heading
   % can't use #1 directly in definition of end part
diff --git a/sphinx/texinputs/sphinxlatexliterals.sty b/sphinx/texinputs/sphinxlatexliterals.sty
index b4eb391740..35fc9ca9fb 100644
--- a/sphinx/texinputs/sphinxlatexliterals.sty
+++ b/sphinx/texinputs/sphinxlatexliterals.sty
@@ -32,6 +32,8 @@
 % - alltt
 % - upquote
 % - needspace
+% - sphinxpackageboxes
+\RequirePackage{sphinxpackageboxes}
 
 % also in sphinxlatexadmonitions.sty:
 % This is a workaround to a "feature" of French lists, when literal block
@@ -60,9 +62,6 @@
 % Skip to next page if not enough space at bottom
 \RequirePackage{needspace}
 
-\newbox\spx@verb@tempboxa
-\newbox\spx@verb@tempboxb
-
 % Based on use of "fancyvrb.sty"'s Verbatim.
 % - with framing allowing page breaks ("framed.sty")
 % - with breaking of long lines (exploits Pygments mark-up),
@@ -109,8 +108,7 @@
 %         "color push" or "color pop"
 % About the produced output:
 %  - it obeys current indentation,
-%  - frame of width \sphinxverbatimborder is \sphinxverbatimsep -arated
-%    from the contents,
+%  - frame with 4 padding parameters and 4 border-width parameters
 %  - the contents use the full available text width, limited by indentation,
 %  - #1 = will be typeset above frame, in a non detachable way,
 %  - #2 = will be typeset below frame, in a non detachable way,
@@ -119,14 +117,27 @@
 % #3 are the contents, and in the context of usage of fancyvrb+framed,
 % it will arrive here already transformed into horizontal boxes,
 % interline penalties and glues.
+%
 \long\def\spx@verb@FrameCommand #1#2#3{%
   % These \hskips are for fancyvrb.sty measuring and will make the
   % framing "adapt" to an indented context.
-  \ifspx@opt@verbatimwithframe\else\sphinxverbatimborder\z@\fi
+  \ifspx@opt@verbatimwithframe\else\spxdimen@pre@border\z@\fi
   \hskip\@totalleftmargin
-  \hskip-\sphinxverbatimsep\hskip-\sphinxverbatimborder
+  \hskip-\spx@pre@border@left\hskip-\spx@pre@padding@left\relax
+  \ifspx@pre@withshadow
+   \ifspx@pre@insetshadow\else
+    \ifdim\spx@pre@shadow@xoffset<\z@\hskip\spx@pre@shadow@xoffset\relax
+    \fi
+   \fi
+  \fi
   \spx@verb@fcolorbox {#1}{#2}{#3}%
-  \hskip-\sphinxverbatimsep\hskip-\sphinxverbatimborder
+  \hskip-\spx@pre@padding@right\hskip-\spx@pre@border@right\relax
+  \ifspx@pre@withshadow
+   \ifspx@pre@insetshadow\else
+    \ifdim\spx@pre@shadow@xoffset>\z@\hskip-\spx@pre@shadow@xoffset\relax
+    \fi
+   \fi
+  \fi
   \hskip-\linewidth \hskip-\@totalleftmargin \hskip\columnwidth
 }%
 \long\def\spx@verb@fcolorbox #1#2#3{%
@@ -138,82 +149,148 @@
   % problematic features regarding color in a context like here where #3
   % may contain an unbalanced "color push".
 %
-  % MEMO: Some PDF viewers have (or had) issues when the external frame is
-  % drawn first, then the background color is added.  So we will draw first
-  % the background color (and let it extend to the frame area) then, hence
-  % on top of it the frame.  And we draw the contents latest.
-%
-  % TODO: add top right bottom left padding possibilities.
-  % Prepare a box with the contents and reserved space for framing.
-  \setbox\z@\hbox{\kern\dimexpr\sphinxverbatimborder+\sphinxverbatimsep\relax
-                  {#3}\kern\dimexpr\sphinxverbatimborder+\sphinxverbatimsep\relax}%
-    \ht\z@ \dimexpr\ht\z@+\sphinxverbatimsep+\sphinxverbatimborder\relax
-    \dp\z@ \dimexpr\dp\z@+\sphinxverbatimsep+\sphinxverbatimborder\relax
-  % Prepare colored background
-  \setbox\tw@\hbox{{\color{VerbatimColor}\vrule\@width\wd\z@\@height\ht\z@\@depth\dp\z@}}%
-  \vbox{#1% continuation hint attached above frame
-            % draw frame border _latest_ to avoid pdf viewer issue
-            % be careful not to cause "color push + contents + color pop"
-        % there will be a small "\lineskip" space here from TeX
-        % the colored background
-        \copy\tw@
-        % stroke the frame
-        \kern-\dimexpr\ht\tw@+\dp\tw@\relax
-        {\color{VerbatimBorderColor}% frame color
-         \hrule\@height\sphinxverbatimborder % width computed by TeX
-         \setbox\tw@\hb@xt@\wd\z@
-              {% the vrule height will be auto computed later by TeX
-               \vrule\@width\sphinxverbatimborder
-               \hss
-               \vrule\@width\sphinxverbatimborder
-              }%
-         \ht\tw@\dimexpr\ht\z@-\sphinxverbatimborder\relax
-         \dp\tw@\dimexpr\dp\z@-\sphinxverbatimborder\relax
-         \box\tw@
-         \hrule\@height\sphinxverbatimborder
-        }% color pop here
-        % now the contents
-        \kern-\dimexpr\ht\tw@+\dp\tw@\relax
-        \box\z@
-        % Former code had a \hrule here so we need to suppress interline glue
-        % to keep exact same output now that it is a \hbox above
+  \setbox\z@\hbox{#3}%
+  \edef\spx@verb@fcolorbox@width@sp
+      {\number\dimexpr\wd\z@+\spx@pre@border@left
+                            +\spx@pre@padding@left
+                            +\spx@pre@padding@right
+                            +\spx@pre@border@right\relax sp}%
+  \vbox{#1% continuation hint attached above frame, uses \spx@verb@fcolorbox@width@sp
+        % the boxes@fcolorbox constructs an \hbox with bbox containing the border
+        \if1% use rounded boxes only if needed and possible
+          \ifdim\spx@pre@radius@topleft    >\z@0\fi
+          \ifdim\spx@pre@radius@topright   >\z@0\fi
+          \ifdim\spx@pre@radius@bottomright>\z@0\fi
+          \ifdim\spx@pre@radius@bottomleft >\z@0\fi
+          1\spx@boxes@fcolorbox{\box\z@}%
+        \else
+          \@ifpackageloaded{pict2e}%
+             {\ifspx@pre@insetshadow
+                \spx@boxes@fcolorbox{\box\z@}%
+              \else
+                \spx@boxes@fcolorbox@rounded{\box\z@}%
+              \fi}%
+             {\spx@boxes@fcolorbox{\box\z@}}%
+        \fi
+        % This \nointerlineskip to maintain legacy spacing when a \hrule was
+        % formerly last prior item in vertical list.  TODO: remove this at 6.0.0 ?
         \nointerlineskip
-        % TODO: add some \lineskip glue here, this is all in a \vbox so can't split
-        #2% continuation hint attached below frame
+        #2% continuation hint attached below frame, uses \spx@verb@fcolorbox@width@sp
        }% end of \vbox
 }%
-\def\spx@fcolorbox@put@c#1{% hide width from framed.sty measuring
-    \moveright.5\wd\tw@\hb@xt@\z@{\hss#1\hss}%
+\def\spx@verb@fcolorbox@put@c#1{% hide width from framed.sty measuring
+    \moveright.5\dimexpr\spx@verb@fcolorbox@width@sp\hb@xt@\z@{\hss#1\hss}%
 }%
-\def\spx@fcolorbox@put@r#1{% right align with contents, width hidden
-    \moveright\dimexpr\wd\tw@-\sphinxverbatimsep-\sphinxverbatimborder\hb@xt@\z@{\hss#1}%
+\def\spx@verb@fcolorbox@put@r#1{% right align with contents, width hidden
+    \moveright\dimexpr\spx@verb@fcolorbox@width@sp-%
+                      \spx@pre@padding@right-%
+                      \spx@pre@border@right\hb@xt@\z@{\hss#1}%
 }%
-\def\spx@fcolorbox@put@l#1{% left align with contents, width hidden
-    \moveright\dimexpr\sphinxverbatimborder+\sphinxverbatimsep\hb@xt@\z@{#1\hss}%
+\def\spx@verb@fcolorbox@put@l#1{% left align with contents, width hidden
+    \moveright\dimexpr\spx@pre@border@left+%
+                      \spx@pre@padding@left\hb@xt@\z@{#1\hss}%
 }%
 %
-\def\sphinxVerbatim@Continued
-   {\csname spx@fcolorbox@put@\spx@opt@verbatimcontinuedalign\endcsname
-    {{\normalcolor\sphinxstylecodecontinued\literalblockcontinuedname}}}%
-\def\sphinxVerbatim@Continues
-   {\csname spx@fcolorbox@put@\spx@opt@verbatimcontinuesalign\endcsname
-    {{\normalcolor\sphinxstylecodecontinues\literalblockcontinuesname}}}%
-\def\sphinxVerbatim@Title
-   {\spx@fcolorbox@put@c{\unhcopy\sphinxVerbatim@TitleBox}}%
+\def\sphinxVerbatim@Continued{%
+    \csname spx@verb@fcolorbox@put@\spx@opt@verbatimcontinuedalign\endcsname
+    {{\normalcolor\sphinxstylecodecontinued\literalblockcontinuedname}}%
+}%
+\def\sphinxVerbatim@Continues{%
+    \csname spx@verb@fcolorbox@put@\spx@opt@verbatimcontinuesalign\endcsname
+    {{\normalcolor\sphinxstylecodecontinues\literalblockcontinuesname}}%
+}%
+\def\sphinxVerbatim@Title{%
+    \spx@verb@fcolorbox@put@c{\unhcopy\sphinxVerbatim@TitleBox}%
+}%
 \let\sphinxVerbatim@Before\@empty
 \let\sphinxVerbatim@After\@empty
 % Defaults are redefined in document preamble according to language
 \newcommand*\literalblockcontinuedname{continued from previous page}%
 \newcommand*\literalblockcontinuesname{continues on next page}%
 %
-\def\sphinxVerbatim@FrameCommand
-   {\spx@verb@FrameCommand\sphinxVerbatim@Before\sphinxVerbatim@After}%
-\def\sphinxVerbatim@FirstFrameCommand
-   {\spx@verb@FrameCommand\sphinxVerbatim@Before\sphinxVerbatim@Continues}%
-\def\sphinxVerbatim@MidFrameCommand
-   {\spx@verb@FrameCommand\sphinxVerbatim@Continued\sphinxVerbatim@Continues}%
-\def\sphinxVerbatim@LastFrameCommand
-   {\spx@verb@FrameCommand\sphinxVerbatim@Continued\sphinxVerbatim@After}%
+\def\sphinxVerbatim@FrameCommand{%
+    \spx@verb@FrameCommand\sphinxVerbatim@Before\sphinxVerbatim@After
+}%
+\def\sphinxVerbatim@FirstFrameCommand{%
+    \ifspx@pre@border@open
+      \let\spx@boxes@fcolorbox@setuphook\spx@verb@boxes@fcolorbox@setuphook@openbottom
+    \fi
+    \spx@verb@FrameCommand\sphinxVerbatim@Before\sphinxVerbatim@Continues
+}%
+\def\sphinxVerbatim@MidFrameCommand{%
+    \ifspx@pre@border@open
+      \let\spx@boxes@fcolorbox@setuphook\spx@verb@boxes@fcolorbox@setuphook@openboth
+    \fi
+    \spx@verb@FrameCommand\sphinxVerbatim@Continued\sphinxVerbatim@Continues
+}%
+\def\sphinxVerbatim@LastFrameCommand{%
+    \ifspx@pre@border@open
+      \let\spx@boxes@fcolorbox@setuphook\spx@verb@boxes@fcolorbox@setuphook@opentop
+    \fi
+    \spx@verb@FrameCommand\sphinxVerbatim@Continued\sphinxVerbatim@After
+}%
+%
+\def\spx@verb@boxes@fcolorbox@setup{%
+%
+  \spx@boxes@border@top   \spx@pre@border@top
+  \spx@boxes@border@right \spx@pre@border@right
+  \spx@boxes@border@bottom\spx@pre@border@bottom
+  \spx@boxes@border@left  \spx@pre@border@left
+  \spx@boxes@border       \spxdimen@pre@border
+%
+  \spx@boxes@padding@top   \spx@pre@padding@top
+  \spx@boxes@padding@right \spx@pre@padding@right
+  \spx@boxes@padding@bottom\spx@pre@padding@bottom
+  \spx@boxes@padding@left  \spx@pre@padding@left
+%
+  \spx@boxes@radius@topleft     \spx@pre@radius@topleft
+  \spx@boxes@radius@topright    \spx@pre@radius@topright
+  \spx@boxes@radius@bottomright \spx@pre@radius@bottomright
+  \spx@boxes@radius@bottomleft  \spx@pre@radius@bottomleft
+%
+%
+  \ifspx@pre@withshadow
+     \spx@boxes@withshadowtrue
+     \spx@boxes@shadow@xoffset \spx@pre@shadow@xoffset
+     \spx@boxes@shadow@yoffset \spx@pre@shadow@yoffset\relax
+  \else
+     \spx@boxes@withshadowfalse
+  \fi
+  \ifspx@pre@insetshadow\spx@boxes@insetshadowtrue\else
+                        \spx@boxes@insetshadowfalse\fi
+  \ifspx@pre@withshadowcolor\spx@boxes@withshadowcolortrue\else
+                            \spx@boxes@withshadowcolorfalse\fi
+  %
+  \ifspx@pre@withbackgroundcolor\spx@boxes@withbackgroundcolortrue\else
+                                \spx@boxes@withbackgroundcolorfalse\fi
+  \sphinxcolorlet{spx@boxes@backgroundcolor}{VerbatimColor}%
+  %
+  \ifspx@pre@withbordercolor\spx@boxes@withbordercolortrue\else
+                            \spx@boxes@withbordercolorfalse\fi
+  \sphinxcolorlet{spx@boxes@bordercolor}{VerbatimBorderColor}%
+  %
+  \ifspx@pre@withshadowcolor\spx@boxes@withshadowcolortrue\else
+                            \spx@boxes@withshadowcolorfalse\fi
+  \sphinxcolorlet{spx@boxes@shadowcolor}{sphinxVerbatimShadowColor}%
+}%
+\def\spx@verb@boxes@fcolorbox@setuphook@openbottom{%
+    \spx@boxes@border@bottom     \z@
+    \spx@boxes@radius@bottomright\z@
+    \spx@boxes@radius@bottomleft \z@
+}%
+\def\spx@verb@boxes@fcolorbox@setuphook@opentop{%
+    \spx@boxes@border@top     \z@
+    \spx@boxes@radius@topright\z@
+    \spx@boxes@radius@topleft \z@
+}%
+\def\spx@verb@boxes@fcolorbox@setuphook@openboth{%
+    \spx@boxes@border@top     \z@
+    \spx@boxes@border@bottom  \z@
+    \spx@boxes@radius@topright\z@
+    \spx@boxes@radius@topleft \z@
+    \spx@boxes@radius@bottomright\z@
+    \spx@boxes@radius@bottomleft \z@
+}%
 
 % For linebreaks inside Verbatim environment from package fancyvrb.
 \newbox\sphinxcontinuationbox
@@ -348,7 +425,7 @@
 % \newcommand\sphinxVerbatimFormatLine[1]{\FV@ObeyTabs{\strut #1}}%
 \newcommand\sphinxVerbatimFormatLine[1]{\strut#1}%
 % MEMO: if verbatimwrapslines is set to true (default) the #1 above is
-% simply \box\spx@verb@tempboxb, from the next two macros.
+% simply \box\spx@tempboxb, from the next two macros.
 % The next two macros are a deep hack of fancyvrb.sty core line processing in
 % order to wrap too long lines, either at spaces and natural break-points,
 % (soft wrap) or optionally at any character (hard wrap).  This requires deep
@@ -367,10 +444,10 @@
 \def\spx@verb@@ProcessLines{%
    \unskip
    \unpenalty
-   \setbox\spx@verb@tempboxb\lastbox
-\ifvoid\spx@verb@tempboxb\else
+   \setbox\spx@tempboxb\lastbox
+\ifvoid\spx@tempboxb\else
    {\spx@verb@@ProcessLines}%
-   \FV@ProcessLine{\box\spx@verb@tempboxb}%
+   \FV@ProcessLine{\box\spx@tempboxb}%
    \global\let\FV@ProcessLine\FV@ProcessLine
    \global\setbox\@tempboxa=\box\@tempboxa
    \aftergroup\spx@verb@@InhibitLineNumber
@@ -401,7 +478,7 @@
      \fi
 % MEMO: \everypar{} was issued earlier (and due to \@setminipage
 % would have been only \@minipagefalse\everypar{} otherwise).
-     \setbox\spx@verb@tempboxa=\vtop{\hsize\linewidth
+     \setbox\spx@tempboxa=\vtop{\hsize\linewidth
           \raggedright\hyphenpenalty\z@\exhyphenpenalty\z@
           \doublehyphendemerits\z@\finalhyphendemerits\z@
 % MEMO: fancyvrb has options obeytabs and tabsize.  Anyhow tab characters
@@ -417,14 +494,14 @@
 % are executed but not the ones at its end.
           \par
           }%
-     \setbox\spx@verb@tempboxa=\vtop{\unvbox\spx@verb@tempboxa
-          \setbox\spx@verb@tempboxb\lastbox
+     \setbox\spx@tempboxa=\vtop{\unvbox\spx@tempboxa
+          \setbox\spx@tempboxb\lastbox
           {\spx@verb@@ProcessLines}%
-          \FV@ProcessLine{\box\spx@verb@tempboxb}%
+          \FV@ProcessLine{\box\spx@tempboxb}%
           \global\let\FV@ProcessLine\FV@ProcessLine
           \global\setbox\@tempboxa=\box\@tempboxa
           }%
-  \unvbox\spx@verb@tempboxa
+  \unvbox\spx@tempboxa
 }%
 %
 % The normal line wrapping allows breaks at spaces and ascii non
@@ -493,7 +570,7 @@
 \long\def\spx@verb@DecideIfWillDoForceWrap{%
     \global\let\spx@verb@maxwidth\z@
     \global\let\spx@verb@minwidth\linewidth
-    \setbox\spx@verb@tempboxa
+    \setbox\spx@tempboxa
     \vtop{\raggedright\hyphenpenalty\z@\exhyphenpenalty\z@
           \doublehyphendemerits\z@\finalhyphendemerits\z@
           \spx@everypar{}\noindent\strut\FV@Line\strut\spx@par
@@ -514,27 +591,27 @@
 % but minwidth must not take into account the last line
 \def\spx@verb@getwidths {%
     \unskip\unpenalty
-    \setbox\spx@verb@tempboxb\lastbox
-    \ifvoid\spx@verb@tempboxb
+    \setbox\spx@tempboxb\lastbox
+    \ifvoid\spx@tempboxb
     \else
-       \setbox\spx@verb@tempboxb\hbox{\unhbox\spx@verb@tempboxb}%
-       \ifdim\spx@verb@maxwidth<\wd\spx@verb@tempboxb
-          \xdef\spx@verb@maxwidth{\number\wd\spx@verb@tempboxb sp}%
+       \setbox\spx@tempboxb\hbox{\unhbox\spx@tempboxb}%
+       \ifdim\spx@verb@maxwidth<\wd\spx@tempboxb
+          \xdef\spx@verb@maxwidth{\number\wd\spx@tempboxb sp}%
        \fi
        \expandafter\spx@verb@getwidths@loop
     \fi
 }%
 \def\spx@verb@getwidths@loop {%
     \unskip\unpenalty
-    \setbox\spx@verb@tempboxb\lastbox
-    \ifvoid\spx@verb@tempboxb
+    \setbox\spx@tempboxb\lastbox
+    \ifvoid\spx@tempboxb
     \else
-       \setbox\spx@verb@tempboxb\hbox{\unhbox\spx@verb@tempboxb}%
-       \ifdim\spx@verb@maxwidth<\wd\spx@verb@tempboxb
-          \xdef\spx@verb@maxwidth{\number\wd\spx@verb@tempboxb sp}%
+       \setbox\spx@tempboxb\hbox{\unhbox\spx@tempboxb}%
+       \ifdim\spx@verb@maxwidth<\wd\spx@tempboxb
+          \xdef\spx@verb@maxwidth{\number\wd\spx@tempboxb sp}%
        \fi
-       \ifdim\spx@verb@minwidth>\wd\spx@verb@tempboxb
-          \xdef\spx@verb@minwidth{\number\wd\spx@verb@tempboxb sp}%
+       \ifdim\spx@verb@minwidth>\wd\spx@tempboxb
+          \xdef\spx@verb@minwidth{\number\wd\spx@tempboxb sp}%
        \fi
        \expandafter\spx@verb@getwidths@loop
     \fi
@@ -656,14 +733,20 @@
             \kern\dimexpr-\dp\strutbox+\sphinxbelowcaptionspace
                  % if no frame (code-blocks inside table cells), remove
                  % the "verbatimsep" whitespace from the top (better visually)
-                 \ifspx@opt@verbatimwithframe\else-\sphinxverbatimsep\fi
+                 \ifspx@opt@verbatimwithframe\else
+                    % but we must now check if there is a background color
+                    \ifspx@pre@withbackgroundcolor\else-\spx@pre@padding@top\fi
+                \fi
                  % caption package adds \abovecaptionskip vspace, remove it
                  \spx@ifcaptionpackage{-\abovecaptionskip}{}\relax}%
      \else
        \vskip\sphinxverbatimsmallskipamount
        \def\sphinxVerbatim@After
           {\nointerlineskip\kern\dimexpr\dp\strutbox
-            \ifspx@opt@verbatimwithframe\else-\sphinxverbatimsep\fi
+            \ifspx@opt@verbatimwithframe\else
+                    % but we must now check if there is a background color
+                    \ifspx@pre@withbackgroundcolor\else-\spx@pre@padding@bottom\fi
+            \fi
             \spx@ifcaptionpackage{-\abovecaptionskip}{}\relax
            \sphinxVerbatim@Title}%
      \fi
@@ -680,14 +763,21 @@
   \fi
   \global\let\sphinxLiteralBlockLabel\empty
   \global\let\sphinxVerbatimTitle\empty
+  % the "FrameCommand"'s will check status of verbatimwithframe option
+  % to decide if to stroke the borders ; ultimately they are also
+  % responsible to attach the "Title".
   \let\FrameCommand     \sphinxVerbatim@FrameCommand
+  % those will also check status of the pre_box-decoration-break option
   \let\FirstFrameCommand\sphinxVerbatim@FirstFrameCommand
   \let\MidFrameCommand  \sphinxVerbatim@MidFrameCommand
   \let\LastFrameCommand \sphinxVerbatim@LastFrameCommand
+  %
   \ifspx@opt@verbatimhintsturnover\else
       \let\sphinxVerbatim@Continued\@empty
       \let\sphinxVerbatim@Continues\@empty
   \fi
+  % initialization for \spx@boxes@fcolorbox from sphinxpackageboxes.sty
+  \spx@verb@boxes@fcolorbox@setup
   \ifspx@opt@verbatimwrapslines
     % deep hack into fancyvrb's internal processing of input lines
     \let\FV@@PreProcessLine\spx@verb@@PreProcessLine
@@ -748,18 +838,31 @@
      \color@begingroup % protect against color leaks (upstream framed.sty bug)
      % will fetch its optional arguments if any
      \OriginalVerbatim
-}
+}%
 {%
   \endOriginalVerbatim
   \color@endgroup % matches the \color@begingroup
   \ifspx@inframed
    \egroup % finish \sphinxVerbatim@ContentsBox vbox
    \nobreak % update page totals
-   \ifdim\dimexpr\ht\sphinxVerbatim@ContentsBox+
+%%%%
+% MEMO (2022/07/09, while preparing 5.1.0 LaTeX CSS-style sphinxsetup options)
+% This test will systematically cause to abandon framing if the code-block
+% is near bottom of a warning-type notice which TeX has not yet decided whether
+% it fits on current page and which is near bottom of page.  Indeed the
+% \pagetotal will already be very near \pagegoal. This is probably a not
+% intended behaviour, and perhaps the whole thing should be removed?  Indeed
+% the result is surprising then because the notice will be split, code-block
+% will be on page 2 and will have no background-color, no border.
+   \ifdim\dimexpr
+         \ht\sphinxVerbatim@ContentsBox+
          \dp\sphinxVerbatim@ContentsBox+
          \ht\sphinxVerbatim@TitleBox+
          \dp\sphinxVerbatim@TitleBox+
-         2\sphinxverbatimsep+\ifspx@opt@verbatimwithframe 2\sphinxverbatimborder+\fi
+         \spx@pre@padding@top+
+         \spx@pre@padding@bottom+
+         \ifspx@opt@verbatimwithframe \spx@pre@border@top+
+                                      \spx@pre@border@bottom+\fi
          % try to account for external frame parameters
          % MEMO: this is because the sphinxheavybox (for warning admonitions)
          %       environment sets \FrameSep and \FrameRule
diff --git a/sphinx/texinputs/sphinxlatexshadowbox.sty b/sphinx/texinputs/sphinxlatexshadowbox.sty
index 4a013ef65b..d9a35eb56c 100644
--- a/sphinx/texinputs/sphinxlatexshadowbox.sty
+++ b/sphinx/texinputs/sphinxlatexshadowbox.sty
@@ -16,74 +16,83 @@
 %
 % Requires:
 \RequirePackage{framed}
+\RequirePackage{sphinxpackageboxes}
 
-% Let's draw the contents first, then the frame and the shadow last,
-% to avoid problems with some pdf viewers.
-\long\def\spx@ShadowFBox#1{%
-  \leavevmode\begingroup
-  % First we prepare a box with the contents and some reserved space for the
-  % frame and inner separation; with more parameters we could allow various
-  % border widths for top, bottom, left, right, but here all are equal.
-  \setbox\@tempboxa
-   \hbox{\kern\sphinxshadowrule
-         \vbox{\kern\sphinxshadowrule
-               \kern\sphinxshadowsep
-               \hbox{\kern\sphinxshadowsep #1\kern\sphinxshadowsep}%
-               \kern\sphinxshadowsep
-               \kern\sphinxshadowrule}%
-         \kern\sphinxshadowrule}%
-  % Now we rebox, adding the colored frame for which space was reserved.
-  \setbox\@tempboxa
-   \hbox{\unhcopy\@tempboxa % not \unhbox to be able to refer to \ht, \wd later
-         \kern-\wd\@tempboxa
-         {\color{sphinxshadowBorderColor}% color push here
-          \vrule\@width\sphinxshadowrule% TeX auto-computes the height
-          \vbox{\hrule\@height\sphinxshadowrule% TeX auto-computes the width
-                \kern\dimexpr\ht\@tempboxa-\sphinxshadowrule\relax
-                % This empty \hbox is here to give width used by \hrule
-                % As \dp\@tempboxa is zero, the \hbox location is at the
-                % bottom of frame.
-                \hbox{\kern\dimexpr\wd\@tempboxa-2\sphinxshadowrule\relax}%
-                \kern\dimexpr\dp\@tempboxa-\sphinxshadowrule\relax
-                \hrule\@height\sphinxshadowrule% TeX auto-computes the width
-                }%
-          \vrule\@width\sphinxshadowrule% TeX auto-computes the height
-         }% color pop will happen here
-        }%
-  % Now we add the shadow.
+\def\spx@shadowbox@boxes@fcolorbox@setup{%
+%
+  \spx@boxes@border@top   \spx@topic@border@top
+  \spx@boxes@border@right \spx@topic@border@right
+  \spx@boxes@border@bottom\spx@topic@border@bottom
+  \spx@boxes@border@left  \spx@topic@border@left
+  \spx@boxes@border       \spxdimen@topic@border
+%
+  \spx@boxes@padding@top   \spx@topic@padding@top
+  \spx@boxes@padding@right \spx@topic@padding@right
+  \spx@boxes@padding@bottom\spx@topic@padding@bottom
+  \spx@boxes@padding@left  \spx@topic@padding@left
+%
+  \spx@boxes@radius@topleft     \spx@topic@radius@topleft
+  \spx@boxes@radius@topright    \spx@topic@radius@topright
+  \spx@boxes@radius@bottomright \spx@topic@radius@bottomright
+  \spx@boxes@radius@bottomleft  \spx@topic@radius@bottomleft\relax
+%
+  \ifspx@topic@withshadow
+     \spx@boxes@withshadowtrue
+     \spx@boxes@shadow@xoffset \spx@topic@shadow@xoffset
+     \spx@boxes@shadow@yoffset \spx@topic@shadow@yoffset\relax
+  \else
+     \spx@boxes@withshadowfalse
+  \fi
+  \ifspx@topic@insetshadow\spx@boxes@insetshadowtrue\else
+                          \spx@boxes@insetshadowfalse\fi
+  \ifspx@topic@withshadowcolor\spx@boxes@withshadowcolortrue\else
+                              \spx@boxes@withshadowcolorfalse\fi
+  %
+  \ifspx@topic@withbackgroundcolor\spx@boxes@withbackgroundcolortrue\else
+                                  \spx@boxes@withbackgroundcolorfalse\fi
+  \sphinxcolorlet{spx@boxes@backgroundcolor}{sphinxTopicBackgroundColor}%
   %
-  % Formerly, shadow was drawn partly on top of frame, but this was before
-  % both frame and shadow acquired colors.  The width of the part of the
-  % shadow on the right is hidden, so it will stick into the right page
-  % margin.
+  \ifspx@topic@withbordercolor\spx@boxes@withbordercolortrue\else
+                                  \spx@boxes@withbordercolorfalse\fi
+  \sphinxcolorlet{spx@boxes@bordercolor}{sphinxTopicBorderColor}%
   %
-  % The frame borders are included into this final \hbox, which is sent back
-  % to \MakeFramed/\endMakeFramed measurements and then finally to page
-  % shipout.  As \advance\hsize-\width appears in \MakeFramed, where \width is
-  % the computed extra width added by the framing plus inner separation (so
-  % actually 2\sphinxshadowrule+2\sphinxshadowsep), this all means that
-  % horizontally the frame will be perfectly adjusted to the *total* text
-  % width limits (i.e. independent of current list nesting; but anyhow
-  % Docutils does not allow nesting of topic within topics or body elements).
-  \hbox{\vbox{\offinterlineskip
-              \hbox{\copy\@tempboxa % not \box as we need \wd and \ht next
-                    % add shadow on right side
-                    \lower\sphinxshadowsize
-                          \hbox{{\color{sphinxshadowShadowColor}%
-                                 \vrule\@height\ht\@tempboxa \@width\sphinxshadowsize}}%
-                    }%
-              \kern-\sphinxshadowsize % shift back vertically to bottom of frame
-              % and add shadow at bottom
-              \moveright\sphinxshadowsize
-                    \vbox{{\color{sphinxshadowShadowColor}%
-                           \hrule\@width\wd\@tempboxa \@height\sphinxshadowsize}}%
-              }%
-        % move left by the size of right shadow so shadow adds no width, and
-        % will stick into right margin
-        % (we did not conceal of course from TeX the depth)
-        \kern-\sphinxshadowsize
-       }%
-  \endgroup
+  \ifspx@topic@withshadowcolor\spx@boxes@withshadowcolortrue\else
+                                  \spx@boxes@withshadowcolorfalse\fi
+  \sphinxcolorlet{spx@boxes@shadowcolor}{sphinxTopicShadowColor}%
+}%
+
+% At 5.1.0 the code formerly here has been refactored and incorporated
+% into more powerful \spx@boxes@fcolorbox from sphinxpackageboxes.sty
+\long\def\spx@ShadowFBox#1{%
+  \leavevmode
+  \setbox\z@\hbox{#1}%
+  \ifspx@topic@withshadow
+   \ifspx@topic@insetshadow\else
+    \ifdim\spx@topic@shadow@xoffset<\z@\hskip\spx@topic@shadow@xoffset\relax
+    \fi
+   \fi
+  \fi
+        \if1% use rounded boxes only if needed and possible
+          \ifdim\spx@topic@radius@topleft    >\z@0\fi
+          \ifdim\spx@topic@radius@topright   >\z@0\fi
+          \ifdim\spx@topic@radius@bottomright>\z@0\fi
+          \ifdim\spx@topic@radius@bottomleft >\z@0\fi
+          1\spx@boxes@fcolorbox{\box\z@}%
+        \else
+          \@ifpackageloaded{pict2e}%
+             {\ifspx@topic@insetshadow
+                \spx@boxes@fcolorbox{\box\z@}%
+              \else
+                \spx@boxes@fcolorbox@rounded{\box\z@}%
+              \fi}%
+             {\spx@boxes@fcolorbox{\box\z@}}%
+        \fi
+  \ifspx@topic@withshadow
+   \ifspx@topic@insetshadow\else
+    \ifdim\spx@topic@shadow@xoffset>\z@\hskip\spx@topic@shadow@xoffset\relax
+    \fi
+   \fi
+  \fi
 }
 
 % Use framed.sty \MakeFramed/\endMakeFramed to allow page breaks for topic
@@ -105,11 +114,13 @@
 %   more sophisticated way on usage of \MakeFramed/\endMakeFramed, and
 %   adjusting to current text indentation.
 \newenvironment{sphinxShadowBox}
-  {\def\FrameCommand {\spx@ShadowFBox }%
+  {%
+   \spx@shadowbox@boxes@fcolorbox@setup
+   \def\FrameCommand {\spx@ShadowFBox }%
    \advance\spx@image@maxheight
-   -\dimexpr2\sphinxshadowrule
-           +2\sphinxshadowsep
-           +\sphinxshadowsize
+   -\dimexpr\spx@topic@border@top+\spx@topic@border@bottom
+           +\spx@topic@padding@top+\spx@topic@padding@bottom
+           +\ifdim\spx@topic@shadow@yoffset<\z@-\fi\spx@topic@shadow@yoffset
            +\baselineskip\relax
    % configure framed.sty not to add extra vertical spacing
    \ltx@ifundefined{OuterFrameSep}{}{\OuterFrameSep\z@skip}%
diff --git a/sphinx/texinputs/sphinxpackageboxes.sty b/sphinx/texinputs/sphinxpackageboxes.sty
index f07b9b64c8..befddf6c1f 100644
--- a/sphinx/texinputs/sphinxpackageboxes.sty
+++ b/sphinx/texinputs/sphinxpackageboxes.sty
@@ -2,21 +2,60 @@
 %
 % change this info string if making any custom modification
 \ProvidesPackage{sphinxpackageboxes}[2022/07/04 v5.1.0 advanced colored boxes]
+% Optionally executes \RequirePackage for:
+%
+% - pict2e.  Ideally we would need a recent version of this package which
+%   allows dimensional arguments to its \moveto, \lineto, etc...  but we add
+%   ourselves some wrappers equivalent to its v0.4a 2020/08/16 version.
 
-% Currently, this file only provides a replacement to the \spx@verb@fcolorbox
-% of sphinxlatexliterals.sty which will draw boxes with a frame having
-% rounded corners, and a background color.
+% Provides box registers \spx@tempboxa, \spx@tempboxb usable in other places
+\newbox\spx@tempboxa
+\newbox\spx@tempboxb
+
+% Internal dimens, conditionals, and color parameters involved
+% in \spx@boxes@fcolorbox@setup which is to be set by callers
+\newif\ifspx@boxes@withshadow         
+\newif\ifspx@boxes@insetshadow         
+\newif\ifspx@boxes@withbackgroundcolor
+\newif\ifspx@boxes@withshadowcolor    
+\newif\ifspx@boxes@withbordercolor    
 %
-% It needs \sphinxverbatimsep, \sphinxverbatimborder and a new parameter
-% \sphinxverbatimradius
+\newdimen\spx@boxes@border
+\newdimen\spx@boxes@border@top
+\newdimen\spx@boxes@border@right
+\newdimen\spx@boxes@border@bottom
+\newdimen\spx@boxes@border@left
 %
-% Executes \RequirePackage for:
+\newdimen\spx@boxes@padding@top
+\newdimen\spx@boxes@padding@right
+\newdimen\spx@boxes@padding@bottom
+\newdimen\spx@boxes@padding@left
 %
-% - pict2e.  Ideally we would need a recent version of this package which
-%   allows dimensional arguments to its \moveto, \lineto, etc...
-%   but we add ourselves some wrapper to facilitate the usage.
+\newdimen\spx@boxes@shadow@xoffset
+\newdimen\spx@boxes@shadow@yoffset
+%
+\newdimen\spx@boxes@radius@topleft % only circular arcs, x-radius same as y-radius
+\newdimen\spx@boxes@radius@topright
+\newdimen\spx@boxes@radius@bottomright
+\newdimen\spx@boxes@radius@bottomleft
+%
+% These colours have to be defined in the "init" codes
+% spx@boxes@bordercolor
+% spx@boxes@backgroundcolor
+% spx@boxes@shadowcolor
 
+%%%%%%%%%%%%%%%%
+% MACROS
+%
+% - \spx@boxes@fcolorbox (4 padding parameters, 4 border widths, 2 shadow widths,
+%   and three colors: background, border and shadow; same as in CSS styling)
+%
+% - \spx@boxes@fcolorbox@insetshadow (same as in CSS styling)
+%
+% - \spx@boxes@fcolorbox@rounded (used for code-blocks): rounded corners using
+%   the picture mode and pict2e package for access to PDF graphics
 
+% This interface is WIP
 % MEMO: we have also successfully tested usage of tcolorbox's \tcbox but
 % decided to use pict2e.sty for the following reasons:
 % 1- an order of magnitude faster for what we want to do,
@@ -26,91 +65,373 @@
 %    (and the additional coding as contributed here).
 
 % In this first installment, the caption and continuation hints of code-blocks
-% are done exactly as formerly; only difference is in the rounded corrners.
+% when using \spx@boxes@fcolorbox@rounded
+% are done exactly as formerly; only difference is in the rounded corners.
 % The space occupied is same, if nothing else is changed.
 
+\def\spx@RequirePackage@PictIIe{%
 \IfFileExists{pict2e.sty}
    {\RequirePackage{pict2e}}
    {\PackageWarningNoLine{sphinx}{%
        The package pict2e is required for rounded boxes.\MessageBreak
        It does not seem to be available on your system.\MessageBreak
-       The verbatimradius setting will thus be ignored}%
+       Options for setting radii will thus be ignored}%
     \AtEndDocument{\PackageWarningNoLine{sphinx}{%
        I issued a warning which may have gotten lost in the\MessageBreak
        gigantic console output: pict2e.sty was not found,\MessageBreak
-       and verbatimradius has been ignored}}\endinput}
-
-% First we define some wrapper to be able to use arguments being (only)
-% dimensions or dimensional expressions.  The \unitlength will always be 1pt.
-\def\spx@moveto(#1,#2)%
-   {\moveto(\strip@pt\dimexpr#1,\strip@pt\dimexpr#2)}
-\def\spx@lineto(#1,#2)%
-   {\lineto(\strip@pt\dimexpr#1,\strip@pt\dimexpr#2)}
-% attention we use here [2] always; and there are two more mandatory
-% arguments, angles, we don't need to worry about them here.
-\def\spx@circlearc#1#2#3{\circlearc[2]%
-    {\strip@pt\dimexpr#1}{\strip@pt\dimexpr#2}{\strip@pt\dimexpr#3}%
+       and radii setting options have been ignored}}%
+   \def\spx@boxes@fcolorbox@rounded{\spx@boxes@fcolorbox}%
+   }%
+}%
+
+
+%//// \spx@boxes@fcolorbox
+% This box will have the same baseline as its argument (which is typeset in
+% horizontal mode).  It takes into account four border widths parameters, four
+% padding parameters, two shadow widths (each possibly negative), and three
+% colors: background, border and shadow.  Its boundary box takes into account
+% all of shadow, border and padding.
+%
+% The customization of the various parameters are under responsability of
+% caller.  At some point of code development the parameters were set
+% by expansion of an \spx@boxes@fcolorbox@setup macro inside
+% \spx@boxes@fcolorbox.  Now this is only a hook, because the initialization
+% will be done by caller rather.
+\let\spx@boxes@fcolorbox@setuphook\@empty
+% The same applies to \spx@boxes@fcolorbox@rounded, also with (same name)
+% \spx@boxes@fcolorbox@setup left to caller configuration.
+%
+% The parameters are interpreted as they would as CSS properties.
+% For the shadow inset variant see separate \spx@boxes@fcolorbox@insetshadow
+\long\def\spx@boxes@fcolorbox#1{%
+  \hbox\bgroup
+  \spx@boxes@fcolorbox@setuphook
+  \setbox\spx@tempboxa
+   \hbox{\kern\dimexpr\spx@boxes@border@left+\spx@boxes@padding@left\relax
+         {#1}%
+         \kern\dimexpr\spx@boxes@padding@right+\spx@boxes@border@right\relax}%
+  \ht\spx@tempboxa
+     \dimexpr\ht\spx@tempboxa+\spx@boxes@border@top+\spx@boxes@padding@top\relax
+  \dp\spx@tempboxa
+     \dimexpr\dp\spx@tempboxa+\spx@boxes@padding@bottom+\spx@boxes@border@bottom\relax
+  \ifspx@boxes@insetshadow
+     \expandafter\spx@boxes@fcolorbox@insetshadow
+  \else
+     \expandafter\spx@boxes@fcolorbox@externalshadow
+  \fi
 }
 
-% TODO: add top right bottom left padding possibilities.
-\long\def\spx@verb@fcolorbox #1#2#3{%
-  % Prepare a box with the contents and reserved space for framing.
-  \setbox\tw@\hbox{\kern\dimexpr\sphinxverbatimborder+\sphinxverbatimsep\relax
-                  {#3}\kern\dimexpr\sphinxverbatimborder+\sphinxverbatimsep\relax}%
-    \ht\tw@ \dimexpr\ht\tw@+\sphinxverbatimsep+\sphinxverbatimborder\relax
-    \dp\tw@ \dimexpr\dp\tw@+\sphinxverbatimsep+\sphinxverbatimborder\relax
+\def\spx@boxes@fcolorbox@externalshadow{%
+  % reserve space to shadow if on left
+  \ifspx@boxes@withshadow
+    \ifdim\spx@boxes@shadow@xoffset<\z@\kern-\spx@boxes@shadow@xoffset\fi
+  \fi
+  % BACKGROUND
+  % draw background and move back to reference point
+  \ifspx@boxes@withbackgroundcolor
+   {\color{spx@boxes@backgroundcolor}%
+    \vrule\@height\ht\spx@tempboxa
+          \@depth\dp\spx@tempboxa
+          \@width\wd\spx@tempboxa
+    \kern-\wd\spx@tempboxa
+    }%
+  \fi
+  % BOX SHADOW
+  % draw shadow and move back to reference point
+  \ifspx@boxes@withshadow
   \vbox{%
-% Prepare a macro for path to be inserted in a picture environment for stroke
-% and fill; the path will be redefined for each of fill or stroke.  This macro
-% does nothing yet.
-\def\spx@dopath{%
-  \spx@moveto(\sphinxverbatimradius,\z@)% \z@ not 0 as our \spx@moveto is quite dumb
-  \spx@lineto(\wd\tw@-\sphinxverbatimborder-\sphinxverbatimradius,\z@)%
-  \spx@circlearc{\wd\tw@-\sphinxverbatimborder-\sphinxverbatimradius}%
-                {\sphinxverbatimradius}%
-                {\sphinxverbatimradius}{-90}{0}%
-  \spx@lineto(\wd\tw@-\sphinxverbatimborder,\ht\tw@+\dp\tw@-\sphinxverbatimborder-\sphinxverbatimradius)%
-  \spx@circlearc{\wd\tw@-\sphinxverbatimborder-\sphinxverbatimradius}
-                {\ht\tw@+\dp\tw@-\sphinxverbatimborder-\sphinxverbatimradius}%
-                {\sphinxverbatimradius}{0}{90}%
-  \spx@lineto(\sphinxverbatimradius,\ht\tw@+\dp\tw@-\sphinxverbatimborder)%
-  \spx@circlearc{\sphinxverbatimradius}%
-                {\ht\tw@+\dp\tw@-\sphinxverbatimborder-\sphinxverbatimradius}%
-                {\sphinxverbatimradius}{90}{180}%
-  \spx@lineto(\z@,\sphinxverbatimradius)%
-  \spx@circlearc{\sphinxverbatimradius}{\sphinxverbatimradius}{\sphinxverbatimradius}{180}{270}%
-}% end of definition of \spx@dopath
+    \moveright\spx@boxes@shadow@xoffset
+    \hbox{\lower\spx@boxes@shadow@yoffset
+          \vbox{\ifspx@boxes@withshadowcolor\color{spx@boxes@shadowcolor}\fi
+                \ifdim\spx@boxes@shadow@yoffset<\z@
+                  \hrule\@height-\spx@boxes@shadow@yoffset
+                  \kern\spx@boxes@shadow@yoffset
+                \fi
+                \setbox\spx@tempboxb\hb@xt@\wd\spx@tempboxa{%
+                 \ifdim\spx@boxes@shadow@xoffset<\z@\vrule\@width-\spx@boxes@shadow@xoffset\fi
+                 \hss
+                 \ifdim\spx@boxes@shadow@xoffset>\z@\vrule\@width\spx@boxes@shadow@xoffset\fi
+                 }%
+                \ht\spx@tempboxb\ht\spx@tempboxa
+                \dp\spx@tempboxb\dp\spx@tempboxa
+                \box\spx@tempboxb
+                \ifdim\spx@boxes@shadow@yoffset>\z@
+                  \kern-\spx@boxes@shadow@yoffset
+                  \hrule\@height\spx@boxes@shadow@yoffset
+                \fi
+                \kern-\dp\spx@tempboxa
+               }% end of \vbox, attention it will have zero depth if yoffset>0
+          \kern-\wd\spx@tempboxa
+          \ifdim\spx@boxes@shadow@xoffset>\z@
+            \kern-\spx@boxes@shadow@xoffset
+          \fi
+         }% end of \hbox, attention its depth is only yoffset if yoffset>0
+       }% end of \vbox
+  \fi % end of shadow drawing, and we are back to horizontal reference point
+  % BOX BORDER
+  \vbox{\ifspx@boxes@withbordercolor\color{spx@boxes@bordercolor}\fi
+        \hrule\@height\spx@boxes@border@top
+           \kern-\spx@boxes@border@top
+        \setbox\spx@tempboxb\hb@xt@\wd\spx@tempboxa
+                  {\vrule\@width\spx@boxes@border@left
+                   \hss\vrule\@width\spx@boxes@border@right
+                  }%
+            \ht\spx@tempboxb\ht\spx@tempboxa
+            \dp\spx@tempboxb\dp\spx@tempboxa
+        \box\spx@tempboxb
+        \kern-\spx@boxes@border@bottom
+        \hrule\@height\spx@boxes@border@bottom
+        \kern-\dp\spx@tempboxa
+       }% attention this box has zero depth due to \hrule at bottom
+  % step back to horizontal reference point
+  \kern-\wd\spx@tempboxa
+  % end of border drawing
+  % CONTENTS
+  % adjust the total depth to include the bottom shadow
+  \ifspx@boxes@withshadow
+    \ifdim\spx@boxes@shadow@yoffset>\z@
+      \dp\spx@tempboxa\dimexpr\dp\spx@tempboxa+\spx@boxes@shadow@yoffset\relax
+    \fi
+  \fi
+  \box\spx@tempboxa
+  % include lateral shadow in total width
+  \ifspx@boxes@withshadow
+    \ifdim\spx@boxes@shadow@xoffset>\z@\kern\spx@boxes@shadow@xoffset\fi
+  \fi
+  \egroup
+}
+
+%//// \spx@boxes@fcolorbox@insetshadow
+% The parameters are interpreted as in CSS styling.
+\def\spx@boxes@fcolorbox@insetshadow{%
+  % BACKGROUND
+  % draw background and move back to reference point
+  \ifspx@boxes@withbackgroundcolor
+   {\color{spx@boxes@backgroundcolor}%
+    \vrule\@height\ht\spx@tempboxa
+          \@depth\dp\spx@tempboxa
+          \@width\wd\spx@tempboxa
+    \kern-\wd\spx@tempboxa
+    }%
+  \fi
+  % BOX SHADOW
+  % draw shadow and move back to reference point
+  \ifspx@boxes@withshadow
+    \hbox{\vbox{\ifspx@boxes@withshadowcolor\color{spx@boxes@shadowcolor}\fi
+% NOTA BENE
+% We deliberately draw shadow partially under an area later covered by frame
+% with the idea to avoid anti-aliasing problems but in fact this may be a bad
+% idea with border is thin
+% Would need some testing and possibly refactoring
+                \ifdim\spx@boxes@shadow@yoffset>\z@
+                  \hrule\@height\dimexpr\spx@boxes@border@top+\spx@boxes@shadow@yoffset\relax
+                  \kern-\spx@boxes@shadow@yoffset
+                  \kern-\spx@boxes@border@top
+                \fi
+                \setbox\spx@tempboxb\hb@xt@\wd\spx@tempboxa{%
+                 \ifdim\spx@boxes@shadow@xoffset>\z@
+                  \vrule\@width\dimexpr\spx@boxes@border@left+\spx@boxes@shadow@xoffset\relax\fi
+                 \hss
+                 \ifdim\spx@boxes@shadow@xoffset<\z@
+                  \vrule\@width\dimexpr-\spx@boxes@shadow@xoffset+\spx@boxes@border@right\relax\fi
+                 }%
+                \ht\spx@tempboxb\ht\spx@tempboxa
+                \dp\spx@tempboxb\dp\spx@tempboxa
+                \box\spx@tempboxb
+                \ifdim\spx@boxes@shadow@yoffset<\z@
+                  \kern\spx@boxes@shadow@yoffset
+                  \kern-\spx@boxes@border@bottom
+                  \hrule\@height\dimexpr-\spx@boxes@shadow@yoffset+\spx@boxes@border@bottom\relax
+                \fi
+                \kern-\dp\spx@tempboxa
+               }% end of \vbox, attention it will have zero depth if yoffset<0
+          \kern-\wd\spx@tempboxa
+         }% end of \hbox, attention its depth is only |yoffset| if yoffset<0
+  \fi % end of inset shadow drawing, and we are back to horizontal reference point
+  % BOX BORDER
+  \vbox{\ifspx@boxes@withbordercolor\color{spx@boxes@bordercolor}\fi
+        \hrule\@height\spx@boxes@border@top
+           \kern-\spx@boxes@border@top
+        \setbox\spx@tempboxb\hb@xt@\wd\spx@tempboxa
+                  {\vrule\@width\spx@boxes@border@left
+                   \hss\vrule\@width\spx@boxes@border@right
+                  }%
+            \ht\spx@tempboxb\ht\spx@tempboxa
+            \dp\spx@tempboxb\dp\spx@tempboxa
+        \box\spx@tempboxb
+        \kern-\spx@boxes@border@bottom
+        \hrule\@height\spx@boxes@border@bottom
+        \kern-\dp\spx@tempboxa
+       }% attention this box has zero depth due to \hrule at bottom
+  % step back to horizontal reference point
+  \kern-\wd\spx@tempboxa
+  % end of border drawing
+  % CONTENTS
+  \box\spx@tempboxa
+  \egroup
+}
+
+
+%%%%%%%%
+% \spx@boxes@fcolorbox@rounded
 %
-        #1% continuation hint attached above frame
-        % there will be a small "\lineskip" space here from TeX
-        % draw frame border _latest_ to avoid pdf viewer issue
-        % be careful not to cause "color push + contents + color pop"
-% MEMO: when pict2e doth a path stroke, the path is in the middle of the line
-% width, i.e. the line extends by half its width to the exterior of the filled
-% path.  This explains some 0.5 things below.
-        \hbox{\setlength{\unitlength}{1pt}% attention to space token here
-% work around for "old" LaTeX (we could use the "picture" package, this
-% would add another dependency)
-              \begin{picture}%
-      (\strip@pt\wd\tw@,\strip@pt\dimexpr\ht\tw@+\dp\tw@)%
-      (\strip@pt\dimexpr-.5\sphinxverbatimborder,\strip@pt\dimexpr-.5\sphinxverbatimborder)%
-              \color{VerbatimColor}% color for background
-              \spx@dopath\fillpath
-              \color{VerbatimBorderColor}% color for border
-\ifspx@opt@verbatimwithframe % even with \sphinxverbatimborder set to 0pt, the
-                             % stroke will produce a visible contour, so we
-                             % must explicitly exclude doing it.
-              \linethickness{\sphinxverbatimborder}%
-              \spx@dopath\strokepath
+% Various radii but only one border-width parameter.
+% Shadow too.
+
+% wrappers for pict2e usage if old
+% Better not to copy over 2020 pict2e definitions in case
+% something internal changes
+% However our wrappers will work ONLY with dimensional inputs
+% (and not 0, only \z@...)
+% No need to pre-expand the arguments
+% Braces in case the expression uses parentheses
+\def\spx@moveto(#1,#2){\moveto({\strip@pt\dimexpr#1\relax},{\strip@pt\dimexpr#2\relax})}
+\def\spx@lineto(#1,#2){\lineto({\strip@pt\dimexpr#1\relax},{\strip@pt\dimexpr#2\relax})}
+% attention here the [N] becomes mandatory
+\def\spx@circlearc[#1]#2#3#4%#5#6
+   {\circlearc[#1]{\strip@pt\dimexpr#2\relax}%
+                  {\strip@pt\dimexpr#3\relax}%
+                  {\strip@pt\dimexpr#4\relax}}
+
+% This macro will when executed in a picture environment prepare a path which
+% is both used for filling backround color and stroking border
+% The coordinate origin in the LaTeX picture environment will be at half the
+% border width (d/2, d/2), d = constant border width
+\def\spx@boxes@borderpath{%
+  \spx@moveto(\spx@boxes@radius@bottomleft,\z@)% \z@ not 0 as our \spx@moveto is quite dumb
+  \spx@lineto(\wd\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@bottomright,\z@)%
+  \spx@circlearc[2]{\wd\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@bottomright}%
+                {\spx@boxes@radius@bottomright}%
+                {\spx@boxes@radius@bottomright}{-90}{0}%
+  \spx@lineto(\wd\spx@tempboxa-\spx@boxes@border,%
+              \ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@topright)%
+  \spx@circlearc[2]{\wd\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@topright}
+                {\ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@topright}%
+                {\spx@boxes@radius@topright}{0}{90}%
+  \spx@lineto(\spx@boxes@radius@topleft,\ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border)%
+  \spx@circlearc[2]{\spx@boxes@radius@topleft}%
+                {\ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@topleft}%
+                {\spx@boxes@radius@topleft}{90}{180}%
+  \spx@lineto(\z@,\spx@boxes@radius@bottomleft)%
+  \spx@circlearc[2]{\spx@boxes@radius@bottomleft}%
+                   {\spx@boxes@radius@bottomleft}%
+                   {\spx@boxes@radius@bottomleft}{180}{270}%
+}% end of definition of \spx@boxes@borderpath
+\def\spx@boxes@borderpath@opentop{%
+  \spx@moveto(\z@,\ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border)%
+  \spx@lineto(\z@,\spx@boxes@radius@bottomleft)%
+  \spx@circlearc[2]{\spx@boxes@radius@bottomleft}%
+                   {\spx@boxes@radius@bottomleft}%
+                   {\spx@boxes@radius@bottomleft}{180}{270}%
+  \spx@lineto(\wd\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@bottomright,\z@)%
+  \spx@circlearc[2]{\wd\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@bottomright}%
+                {\spx@boxes@radius@bottomright}%
+                {\spx@boxes@radius@bottomright}{-90}{0}%
+  \spx@lineto(\wd\spx@tempboxa-\spx@boxes@border,%
+              \ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border)%
+}% end of definition of \spx@boxes@borderpath@opentop
+\def\spx@boxes@borderpath@openbottom{%
+  \spx@moveto(\wd\spx@tempboxa-\spx@boxes@border,\z@)%
+  \spx@lineto(\wd\spx@tempboxa-\spx@boxes@border,%
+              \ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@topright)%
+  \spx@circlearc[2]{\wd\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@topright}
+                {\ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@topright}%
+                {\spx@boxes@radius@topright}{0}{90}%
+  \spx@lineto(\spx@boxes@radius@topleft,\ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border)%
+  \spx@circlearc[2]{\spx@boxes@radius@topleft}%
+                {\ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border-\spx@boxes@radius@topleft}%
+                {\spx@boxes@radius@topleft}{90}{180}%
+  \spx@lineto(\z@,\z@)%
+}% end of definition of \spx@boxes@borderpath@openbottom
+\def\spx@boxes@borderpath@openboth{%
+  \spx@moveto(\wd\spx@tempboxa-\spx@boxes@border,\z@)%
+  \spx@lineto(\wd\spx@tempboxa-\spx@boxes@border,%
+              \ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border)%
+  \spx@moveto(\z@,\ht\spx@tempboxa+\dp\spx@tempboxa-\spx@boxes@border)%
+  \spx@lineto(\z@,\z@)%
+}% end of definition of \spx@boxes@borderpath@openboth
+
+\long\def\spx@boxes@fcolorbox@rounded #1{%
+  \hbox{%
+   \spx@boxes@fcolorbox@setuphook
+   % reserve space to shadow if on left
+   \ifspx@boxes@withshadow
+     \ifdim\spx@boxes@shadow@xoffset<\z@\kern-\spx@boxes@shadow@xoffset\fi
+   \fi
+   \vbox{%
+     % adjust vertical bbox
+     \ifspx@boxes@withshadow
+       \ifdim\spx@boxes@shadow@yoffset<\z@
+           \kern-\spx@boxes@shadow@yoffset
+       \fi
+     \fi
+     \setlength{\unitlength}{1pt}%
+     \setbox\spx@tempboxa
+     \hbox{\kern\dimexpr\spx@boxes@border+\spx@boxes@padding@left\relax
+           {#1}%
+           \kern\dimexpr\spx@boxes@padding@right+\spx@boxes@border\relax}%
+     \ht\spx@tempboxa
+     \dimexpr\ht\spx@tempboxa+\spx@boxes@border+\spx@boxes@padding@top\relax
+     \dp\spx@tempboxa
+     \dimexpr\dp\spx@tempboxa+\spx@boxes@padding@bottom+\spx@boxes@border\relax
+     \hbox{%
+   \begin{picture}%
+      % \strip@pt\dimexpr fot work around "old" LaTeX picture limitation
+      % (we could use the "picture" package, this would add another dependency)
+      (\strip@pt\wd\spx@tempboxa,\strip@pt\dimexpr\ht\spx@tempboxa+\dp\spx@tempboxa)%
+      (\strip@pt\dimexpr-.5\spx@boxes@border,\strip@pt\dimexpr-.5\spx@boxes@border)%
+\ifspx@boxes@withshadow
+              \color{spx@boxes@shadowcolor}%
+              \put(\dimexpr\ifdim\spx@boxes@shadow@xoffset<\z@-\fi
+                           0.5\spx@boxes@border+\spx@boxes@shadow@xoffset,%
+                   \dimexpr\ifdim\spx@boxes@shadow@yoffset<\z@\else-\fi
+                           0.5\spx@boxes@border-\spx@boxes@shadow@yoffset)
+                   {\spx@boxes@borderpath\fillpath}%
+              {\ifspx@boxes@withbackgroundcolor\else
+                   \color{white}% or rather try to use page color?
+                   \spx@boxes@borderpath\fillpath
+              \fi}%
 \fi
-              \end{picture}}%
-        % now the contents
-        \kern-\dimexpr\ht\tw@+\dp\tw@\relax
-        \copy\tw@ % attention that #2 will need \wd\tw@
-        \nointerlineskip
-        % TODO: add some \lineskip glue here, this is all in a \vbox so can't split
-        #2% continuation hint attached below frame
-       }% end of \vbox
+{\ifspx@boxes@withbackgroundcolor
+              \color{spx@boxes@backgroundcolor}%
+              \spx@boxes@borderpath\fillpath
+\fi}%
+\ifdim\spx@boxes@border>\z@
+% even with \spx@boxes@border set to 0pt as done if verbatimwithframe=false
+% stroke will produce a visible contour, so we exclude doing it in that case
+    \ifspx@boxes@withbordercolor
+              \color{spx@boxes@bordercolor}%
+    \fi
+              \linethickness{\spx@boxes@border}%
+              \ifdim\spx@boxes@border@top=\z@
+                    \ifdim\spx@boxes@border@bottom=\z@
+                          \spx@boxes@borderpath@openboth
+                    \else \spx@boxes@borderpath@opentop
+                    \fi
+              \else
+              \ifdim\spx@boxes@border@bottom=\z@
+                    \spx@boxes@borderpath@openbottom
+              \else\spx@boxes@borderpath\strokepath
+              \fi\fi
+              \strokepath
+\fi
+   \end{picture}}% end of picture \hbox in \vbox
+   % back-up vertically for outputting the contents
+   \kern-\dimexpr\ht\spx@tempboxa+\dp\spx@tempboxa\relax
+     % adjust vertical bbox
+     \ifspx@boxes@withshadow
+       \ifdim\spx@boxes@shadow@yoffset>\z@
+           \dp\spx@tempboxa\dimexpr\dp\spx@tempboxa+\spx@boxes@shadow@yoffset\relax
+       \fi
+     \fi
+   \box\spx@tempboxa
+   }% end of \vbox
+  % include lateral shadow in total width
+  \ifspx@boxes@withshadow
+    \ifdim\spx@boxes@shadow@xoffset>\z@\kern\spx@boxes@shadow@xoffset\fi
+  \fi
+  }% end of \hbox
 }%
 
+
 \endinput