Heading with triangle arrows (from https://parkji.co.uk/2011/08/04/enhancing-heading-styles-using-after.html)

heading-arrows.css

h1 {
    background: #000000;
    color: #FFFFFF;
    font-size: 20px;
    font-weight: bold;
    padding: 5px;
    position: relative;
}
h1:after {
    border-color: #000000 transparent transparent;
    border-style: solid;
    border-width: 10px;
    content: " ";
    position: absolute;
    bottom: -20px;
    left: 10px;
}