Introduce PostCSS for auto-prefixing, extract vendors in chunk.
.diff-viewer-wrapper {margin-top: 5px;}
.diff-panel {border: 1px solid gray; width: 300px; heigth: 250px;}
del { text-decoration: none; color: #b30000; background: #fadad7;}
ins { background: #eaf2c2; color: #406619; text-decoration: none; }