* {
    border: 0;
    box-sizing: border-box;
    margin: 0;
    padding: 0;

}

:root {
    --hue: 223;
    --bg: hsl(var(--hue), 10%, 90%);
    --fg: hsl(var(--hue), 10%, 10%);
    font-size: calc(16px + (24 - 16) * (100vw - 320px) / (1280 - 320));
}

body {
    background: var(--bg);
    color: var(--fg);
    font: 1em/1.5 sans-serif;
    height: 100vh;
    display: grid;
    place-items: center;
}

.pl {
    display: block;
    width: 6.25em;
    height: 6.25em;
}

.pl__ring,
.pl__ball {
    animation: ring 2s ease-out infinite;
}

.pl__ball {
    animation-name: ball;
}

/* Dark theme  */
@media (prefers-color-scheme: dark) {
    :root {
        --bg: hsl(var(--hue), 10%, 10%);
        --fg: hsl(var(--hue), 10%, 90%);
    }
}

/* Animation */
@keyframes ring {
    from {
        stroke-dasharray: 0 257 0 0 1 0 0 258;
    }

    25% {
        stroke-dasharray: 0 0 0 0 257 0 258 0;
    }

    50%,
    to {
        stroke-dasharray: 0 0 0 0 0 515 0 0;
    }
}

@keyframes ball {

    from,
    50% {
        animation-timing-function: ease-in;
        stroke-dashoffset: 1;
    }

    64% {
        animation-timing-function: ease-in;
        stroke-dashoffset: -109;
    }

    78% {
        animation-timing-function: ease-in;
        stroke-dashoffset: -145;
    }

    92% {
        animation-timing-function: ease-in;
        stroke-dashoffset: -157;
    }

    57%,
    71%,
    85%,
    99%,
    to {
        animation-timing-function: ease-out;
        stroke-dashoffset: -163;
    }
}