CSS
Rely on constant values like px
when defining should-be-constant or calculated elements.
Flex
vs Grid
Flexbox is for spreading elements out into one direction (and they might wrap onto the next line).
Grid is for positioning elements into a specific grid, so two dimensions (X and Y).
Position relative
or absolute
allows you to force an element to change its position regardless of the flow of components around it.
Suppress visited link color change:
a, a:visited, a:hover, a:active { color: inherit; }
Adjust Border Radius (how curved are the border corners):
borderRadius: "10px"
details
summary
default pointer/* firefox */ details > summary:first-of-type { list-style-type: none; } /* chrome */ ::-webkit-details-marker { display:none; }