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

:root {
    --hue: 223;
    --bg: hsl(var(--hue), 90%, 95%);
    --fg: hsl(var(--hue), 90%, 5%);
    --trans-dur: 0.3s;
    font-size: calc(16px + (24 - 16) * (100vw - 320px) / (1280 - 320));
}

body {
    color: var(--fg);
    font: 1em/1.5 sans-serif;
    height: 100vh;
    display: grid;
    place-items: center;
    transition: background-color var(--trans-dur);
    background: linear-gradient(to right, #000000, #3533cd);
    cursor: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="30" height="30" viewBox="0 0 24 24"><path fill="%2300F9FF" stroke="%2300F9FF" stroke-width="2" d="M5.5 3.21V20.8c0 .45.54.67.85.35l4.86-4.86a.5.5 0 0 1 .35-.15h6.87a.5.5 0 0 0 .35-.85L6.35 2.85a.5.5 0 0 0-.85.35Z"></path></svg>')16 16, auto; /* 16 16 centers the cursor */
}

.preloader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to right, #000000, #3533cd);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 1s ease; /* Transition effect */
    opacity: 1;
}

.preloader.fade-out {
    opacity: 0; /* Fade out effect */
}

main {
    padding: 1.5em 0;
}

.ip {
    width: 16em;
    height: 8em;
}

.ip__track {
    stroke: hsl(var(--hue), 90%, 90%);
    transition: stroke var(--trans-dur);
}

.ip__worm1,
.ip__worm2 {
    animation: worm1 2s linear infinite;
}

.ip__worm2 {
    animation-name: worm2;
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
    :root {
        --bg: hsl(var(--hue), 90%, 5%);
        --fg: hsl(var(--hue), 90%, 95%);
    }

    .ip__track {
        stroke: hsl(var(--hue), 90%, 15%);
    }
}

/* Animation */
@keyframes worm1 {
    from {
        stroke-dashoffset: 0;
    }
    50% {
        animation-timing-function: steps(1);
        stroke-dashoffset: -358;
    }
    50.01% {
        animation-timing-function: linear;
        stroke-dashoffset: 358;
    }
    to {
        stroke-dashoffset: 0;
    }
}

@keyframes worm2 {
    from {
        stroke-dashoffset: 358;
    }
    50% {
        stroke-dashoffset: 0;
    }
    to {
        stroke-dashoffset: -358;
    }
}