<div id="css-hightooth-bg"><div id="css-hightooth-actual"></div></div>

#css-hightooth-bg {
    background: radial-gradient(circle, #ac1d1c, #eca);
    height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    max-width: 500px;
}
#css-hightooth-actual {
    height: 90px;
    width: 30px;
    background: linear-gradient(to bottom right, white, white 50%, transparent 50%, transparent), linear-gradient(to top, transparent 30px, black 30px, white);
    background-size: 30px 30px, 100% 100%;
    background-repeat: repeat-x, no-repeat;
    background-position: left bottom, bottom;
}