In HTML output, for lists that have an -indent argument, just use

a uniform indentation in CSS adapted to the viewport width and
ignore the value of the argument taken from mdoc(7).  While
author-specified widths somewhat work as a micro-optimization in
terminal and typeset output, they are nothing but harmful in HTML
style= attributes because they break responsive design, whereas
using a reasonable default indent almost never results in ugly
output.  Admittedly, the author-specified width might occasionally
look even better, but only slightly so, and only for some viewport
sizes.
Based on guidance provided by John Gardner.

1 files changed, 2 insertions, 2 deletions

diff --git a/mandoc.css b/mandoc.css
index 916ca0b9..34fcc899 100644
--- a/mandoc.css
+++ b/mandoc.css
@@ -68,7 +68,7 @@ div.manual-text {
 /* Displays and lists. */
 
 .Bd { }
-.D1 {		margin-left: 3.8em; }
+.Bd-indent {	margin-left: 3.8em; }
 
 ul.Bl-bullet {	list-style-type: disc;
 		padding-left: 1em; }
@@ -239,7 +239,7 @@ a.In { }
 div.manual-text {
 		margin-left: 0.5em; }
 .Sh, .Ss {	margin-left: 0em; }
-.D1 {		margin-left: 2em; }
+.Bd-indent {	margin-left: 2em; }
 dl.Bl-hang > dd {
 		margin-left: 2em; }
 dl.Bl-tag {	margin-left: 2em; }