github 80 char line.css

.diff-line.line {
    position: relative;
}
.diff-line:not(.gc).line::before {
    -webkit-user-select:none;
    pointer-events:none;
    left: 10px;
    color: transparent;
    content: "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
    border-right: 1px dotted rgba(0, 0, 0, 0.5);
    height: 1.3em;
    position: absolute;
    top: 0;
}