// https://baijiahao.baidu.com/s?id=1765922285436428843&wfr=spider&for=pc

.box {
    --w: 120px;
    --n: 20; /* control the number of dashes */
    --d: 8deg; /* control the distance between dashes */
    --t: 5px; /* control the thickness of border*/
    --c: red; /* control the coloration */

    width: var(--w);
    height: var(--w);
    aspect-ratio: 1;
    display: inline-grid;
    place-content: center;
    font-size: 40px;
    font-family: sans-serif;
    font-weight: bold;
    position: relative;
}
.box::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 50%;
    padding: var(--t);
    background: var(--c);
    -webkit-mask: linear-gradient(#0000 0 0) content-box,
        repeating-conic-gradient(
            from calc(var(--d) / 2),
            #000 0 calc(360deg / var(--n) - var(--d)),
            #0000 0 calc(360deg / var(--n))
        );
    -webkit-mask-composite: source-in;
    mask: linear-gradient(#0000 0 0) content-box,
        repeating-conic-gradient(
            from calc(var(--d) / 2),
            #000 0 calc(360deg / var(--n) - var(--d)),
            #0000 0 calc(360deg / var(--n))
        );
    mask-composite: intersect;
}