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

:root {
    --hue: 223;
    --off-hue: 3;
    --on-hue1: 123;
    --on-hue2: 168;
    --fg: hsl(var(--hue), 10%, 90%);
    --primary: hsl(var(--hue), 90%, 50%);
    --trans-dur: 0.6s;
    --trans-timing: cubic-bezier(0.65, 0, 0.35, 1);
}

/*body,*/
input {
    font: 1em/1.5 sans-serif;
}

.container {
    background-image: linear-gradient(45deg, hsl(var(--hue), 10%, 20%), hsl(var(--hue), 10%, 10%));
    color: var(--fg);
    display: flex;
    height: 400px;
    font-size: calc(40px + (60 - 40) * (100vw - 320px) / (2560 - 320));
    transition:
        background-color var(--trans-dur),
        color var(--trans-dur);
}

.switch,
.switch__input {
    -webkit-tap-highlight-color: #0000;
}

.switch {
    display: block;
    margin: auto;
    position: relative;
    width: 5em;
    height: 3em;
}

.switch__base-outer,
.switch__base-inner {
    display: block;
    position: absolute;
}

.switch__base-outer {
    border-radius: 1.25em;
    box-shadow:
        -0.125em -0.125em 0.25em hsl(var(--hue), 10%, 30%),
        0.125em 0.125em 0.125em hsl(var(--hue), 10%, 30%) inset,
        0.125em 0.125em 0.25em hsl(0, 0%, 0%),
        -0.125em -0.125em 0.125em hsl(var(--hue), 10%, 5%) inset;
    top: 0.125em;
    left: 0.125em;
    width: 4.75em;
    height: 2.75em;
}

.switch__base-inner {
    border-radius: 1.125em;
    box-shadow:
        -0.25em -0.25em 0.25em hsl(var(--hue), 10%, 30%) inset,
        0.0625em 0.0625em 0.125em hsla(var(--hue), 10%, 30%),
        0.125em 0.25em 0.25em hsl(var(--hue), 10%, 5%) inset,
        -0.0625em -0.0625em 0.125em hsla(var(--hue), 10%, 5%);
    top: 0.375em;
    left: 0.375em;
    width: 4.25em;
    height: 2.25em;
}

.switch__base-neon {
    display: block;
    overflow: visible;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: auto;
}

.switch__base-neon path {
    stroke-dasharray: 0 104.26 0;
    transition: stroke-dasharray var(--trans-dur) var(--trans-timing);
}

.switch__input {
    outline: transparent;
    position: relative;
    width: 100%;
    height: 100%;
    -webkit-appearance: none;
    appearance: none;
}

.switch__input:before {
    border-radius: 0.125em;
    box-shadow: 0 0 0 0.125em hsla(var(--hue), 90%, 50%, 0);
    content: "";
    display: block;
    position: absolute;
    inset: -0.125em;
    transition: box-shadow 0.15s linear;
}

.switch__input:focus-visible:before {
    box-shadow: 0 0 0 0.125em var(--primary);
}

.switch__knob,
.switch__knob-container {
    border-radius: 1em;
    display: block;
    position: absolute;
}

.switch__knob {
    background-color: hsl(var(--hue), 10%, 15%);
    background-image:
        radial-gradient(88% 88% at 50% 50%, hsl(var(--hue), 10%, 20%) 47%, hsla(var(--hue), 10%, 20%, 0) 50%),
        radial-gradient(88% 88% at 47% 47%, hsl(var(--hue), 10%, 85%) 45%, hsla(var(--hue), 10%, 85%, 0) 50%),
        radial-gradient(65% 70% at 40% 60%, hsl(var(--hue), 10%, 20%) 46%, hsla(var(--hue), 10%, 20%, 0) 50%);
    box-shadow:
        -0.0625em -0.0625em 0.0625em hsl(var(--hue), 10%, 15%) inset,
        -0.125em -0.125em 0.0625em hsl(var(--hue), 10%, 5%) inset,
        0.75em 0.25em 0.125em hsla(0, 0%, 0%, 0.8);
    width: 2em;
    height: 2em;
    transition: transform var(--trans-dur) var(--trans-timing);
}

.switch__knob-container {
    overflow: hidden;
    top: 0.5em;
    left: 0.5em;
    width: 4em;
    height: 2em;
}

.switch__knob-neon {
    display: block;
    width: 2em;
    height: auto;
}

.switch__knob-neon circle {
    opacity: 0;
    stroke-dasharray: 0 90.32 0 54.19;
    transition:
        opacity var(--trans-dur) steps(1, end),
        stroke-dasharray var(--trans-dur) var(--trans-timing);
}

.switch__knob-shadow {
    border-radius: 50%;
    box-shadow: 0.125em 0.125em 0.125em hsla(0, 0%, 0%, 0.9);
    display: block;
    position: absolute;
    top: 0.5em;
    left: 0.5em;
    width: 2em;
    height: 2em;
    transition: transform var(--trans-dur) var(--trans-timing);
}

.switch__led {
    background-color: hsl(var(--off-hue), 90%, 70%);
    border-radius: 50%;
    box-shadow:
        0 -0.0625em 0.0625em hsl(var(--off-hue), 90%, 40%) inset,
        0 0 0.125em hsla(var(--off-hue), 90%, 70%, 0.3),
        0 0 0.125em hsla(var(--off-hue), 90%, 70%, 0.3),
        0.125em 0.125em 0.125em hsla(0, 0%, 0%, 0.5);
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    width: 0.25em;
    height: 0.25em;
    transition:
        background-color var(--trans-dur) var(--trans-timing),
        box-shadow var(--trans-dur) var(--trans-timing);
}

.switch__text {
    overflow: hidden;
    position: absolute;
    width: 1px;
    height: 1px;
}

.switch__input:checked ~ .switch__led {
    background-color: hsl(var(--on-hue1), 90%, 70%);
    box-shadow:
        0 -0.0625em 0.0625em hsl(var(--on-hue1), 90%, 40%) inset,
        0 -0.125em 0.125em hsla(var(--on-hue1), 90%, 70%, 0.3),
        0 0.125em 0.125em hsla(var(--on-hue1), 90%, 70%, 0.3),
        0.125em 0.125em 0.125em hsla(0, 0%, 0%, 0.5);
}

.switch__input:checked ~ .switch__base-neon path {
    stroke-dasharray: 52.13 0 52.13;
}

.switch__input:checked ~ .switch__knob-shadow,
.switch__input:checked ~ .switch__knob-container .switch__knob {
    transform: translateX(100%);
}

.switch__input:checked ~ .switch__knob-container .switch__knob-neon circle {
    opacity: 1;
    stroke-dasharray: 45.16 0 45.16 54.19;
    transition-timing-function: steps(1, start), var(--trans-timing);
}