https://en.wikipedia.org/wiki/Cascading_Style_Sheets
===Primary CSS unit===
1. Font sizing with rem (root em) http://snook.ca/archives/html_and_css/font-size-with-rem
2. https://mindtheshift.wordpress.com/2015/04/02/r-i-p-rem-viva-css-reference-pixel/
===Colors===
1. https://developer.mozilla.org/de/docs/Web/CSS/Farben
===Use of pseudo classes===
Examples
%%.article aside li:first-child {
border-top: 0 none;
margin-top: 0;
padding-top: 0;
}
.article aside li {
border-top: 1px solid #eee;
line-height: 16px;
margin-top: 0;
padding: 6px 0 6px 80px;
position: relative;
}%%
===force line break===
%%overflow-wrap: break-word;%%
%% table {
table-layout: fixed;
width: 100%;
}
table td {
overflow-wrap: break-word;
} %%