body { margin: 0; }
canvas { width: 100vw; height: 100vh; }
* {
    border: 0;
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
:root {
    --hue: 223;
    --bg: #1b1b1b; /* Updated background color */
    --fg: hsl(var(--hue),90%,10%);
    --primary: hsl(var(--hue),90%,60%);
    --secondary: hsl(283,90%,60%);
    --trans-dur: 0.3s;
    --bezier: cubic-bezier(0.65,0,0.35,1);
    font-size: calc(14px + (30 - 14) * (100vw - 280px) / (3840 - 280));
}
body {
    background-color: var(--bg);
    color: var(--fg);
    display: flex;
    font: 1em/1.5 sans-serif;
    height: 100vh;
    transition:
        background-color var(--trans-dur),
        color var(--trans-dur);
}
.pl {
    --dur: 5s;
    --size: 8em;
    --bar-width: calc(var(--size) * 0.25);
    aspect-ratio: 1 / 1;
    display: flex;
    justify-content: space-between;
    margin: auto;
    width: var(--size);
}
.pl__bar {
    background-color: var(--primary);
    position: relative;
    width: var(--bar-width);
    height: 100%;
    transform-style: preserve-3d;
    animation:
        bar-color var(--dur) step-end infinite,
        bar-spin var(--dur) var(--bezier) infinite;
}
.pl__bar:before,
.pl__bar:after {
    animation-timing-function: step-end;
    background-color: var(--fg);
    content: "";
    display: block;
    position: absolute;
    top: 50%;
    left: 0;
    width: var(--bar-width);
    height: var(--bar-width);
    transition: background-color var(--trans-dur);
}
.pl__bar:before {
    animation-name: bar-end-1;
    transform: translateY(-50%) rotateX(90deg) translateZ(calc(var(--size) / 2 + 1px));
}
.pl__bar:after {
    animation-name: bar-end-2;
    border-radius: 50%;
    bottom: 0;
    transform: translateY(-50%) rotateX(-90deg) translateZ(calc(var(--size) / 2 + 1px));
}
.pl__bar:nth-child(2),
.pl__bar:nth-child(3) {
    animation-delay: calc(var(--dur) * -0.96);
}
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #1b1b1b; /* Updated background color */
        --fg: hsl(var(--hue),90%,90%);
    }
}
@keyframes bar-color {
    from,
    75%,
    to {
        background-color: var(--primary);
    }
    25%,
    50% {
        background-color: var(--secondary);
    }
}
@keyframes bar-spin {
    from {
        transform: rotateX(0);
    }
    25% {
        transform: rotateX(-0.25turn);
    }
    50% {
        transform: rotateX(-0.5turn);
    }
    75% {
        transform: rotateX(-0.75turn);
    }
    to {
        transform: rotateX(-1turn);    
    }
}
@keyframes bar-end-1 {
    from,
    25%,
    to {
        background-color: var(--fg);
        border-radius: 0;
    }
    50% {
        background-color: var(--secondary);
        border-radius: 50%;
    }
    75% {
        background-color: var(--primary);
        border-radius: 50%;
    }
}
@keyframes bar-end-2 {
    from,
    to {
        background-color: var(--primary);
        border-radius: 0;
    }
    25% {
        background-color: var(--secondary);
        border-radius: 0;
    }
    50%,
    75% {
        background-color: var(--fg);
        border-radius: 50%;
    }
}