<h1>:hover</h1>
<nav class="blocks">
  <a href="#" class="block" style="--bg: var(--gradient-1);">
    <div class="block__item"></div>
  </a>
  <a href="#" class="block" style="--bg: var(--gradient-2);">
    <div class="block__item"></div>
  </a>
  <a href="#" class="block" style="--bg: var(--gradient-3);">
    <div class="block__item"></div>
  </a>
  <a href="#" class="block" style="--bg: var(--gradient-4);">
    <div class="block__item"></div>
  </a>
  <a href="#" class="block" style="--bg: var(--gradient-5);">
    <div class="block__item"></div>
  </a>
  <a href="#" class="block" style="--bg: var(--gradient-6);">
    <div class="block__item"></div>
  </a>
  <a href="#" class="block" style="--bg: var(--gradient-7);">
    <div class="block__item"></div>
  </a>
  <a href="#" class="block" style="--bg: var(--gradient-8);">
    <div class="block__item"></div>
  </a>
  <a href="#" class="block" style="--bg: var(--gradient-9);">
    <div class="block__item"></div>
  </a>
</nav>

:root {
  --lerp-0: 1;
  --lerp-1: 0.5625;
  --lerp-2: 0.25;
  --lerp-3: 0.0625;
  --lerp-4: 0;
}

*,
*:after,
*:before {
  box-sizing: border-box;
}

h1 {
  position: fixed;
  bottom: var(--size-4);
  right: var(--size-4);
  margin: 0;
  color: var(--gray-0);
}

body {
  display: grid;
  place-items: center;
  min-height: 100vh;
  font-family:  'Google Sans', sans-serif, system-ui;
  background: var(--gradient-1);
}

:root {
  --lerp-0: 1;
  --lerp-1: 0.5625;
  --lerp-2: 0.25;
  --lerp-3: 0.0625;
  --lerp-4: 0;
}

.blocks {
  display: flex;
  list-style-type: none;
  padding: var(--size-2);
  border-radius: var(--radius-3);
  gap: var(--size-4);
  background: hsl(0 0% 100% / 0.5);
  align-items: center;
  justify-content: center;
  align-content: center;
  backdrop-filter: blur(10px);
}

.blocks:hover {
  --show: 1;
}

.block {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  align-content: center;
  transition: flex 0.2s;
  flex: calc(0.2 + (var(--lerp, 0) * 1.5));
  position: relative;
}

.block:after {
  content: '';
  width: 5%;
  aspect-ratio: 1;
  background: var(--text-1);
  position: absolute;
  bottom: 10%;
  left: 50%;
  border-radius: var(--radius-3);
  transform: translate(-50%, -50%);
  z-index: -1;
}

.block:before {
  content: '';
  position: absolute;
  width: calc(100% + var(--size-4));
  bottom: 0;
  aspect-ratio: 1 / 2;
  left: 50%;
  transition: transform 0.2s;
  transform-origin: 50% 100%;
  transform: translateX(-50%) scaleY(var(--show, 0));
  z-index: -1;
}

.block .block__item {
  transition: outline 0.2s;
  outline: transparent var(--size-1) solid;
}

:is(.block:hover, .block:focus-visible) .block__item {
  outline: var(--surface-1) var(--size-1) solid;
}

.block {
  outline: none;
}

.block__item {
  width: 100%;
  aspect-ratio: 1;
  border-radius: var(--radius-3);
  background: var(--bg), var(--surface-1);
  display: inline-block;
  transition: transform 0.2s;
  transform-origin: 50% 100%;
  position: relative;
  transform: translateY(calc(var(--lerp) * -75%));
}

.block__item:after {
  content: '';
  position: absolute;
  height: 100%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  aspect-ratio: 1;
  border-left: var(--size-2) solid white;
  border-top: var(--size-2) solid white;
  border-radius: var(--radius-3);
  mask: linear-gradient(135deg, black, transparent 50%);
}

@media(prefers-color-scheme: dark) {
  body {
    background: var(--gradient-23);
  }
  .blocks {
    background: hsl(0 0% 0% / 0.5);
  }
}


:is(.block:hover, .block:focus-visible) {
  --lerp: var(--lerp-0);
  z-index: 5;
}
.block:has( + :is(.block:hover, .block:focus-visible)),
:is(.block:hover, .block:focus-visible) + .block {
  --lerp: var(--lerp-1);
  z-index: 4;
}
.block:has( + .block + :is(.block:hover, .block:focus-visible)),
:is(.block:hover, .block:focus-visible) + .block + .block {
  --lerp: var(--lerp-2);
  z-index: 3;
}
.block:has( + .block + .block + :is(.block:hover, .block:focus-visible)),
:is(.block:hover, .block:focus-visible) + .block + .block + .block {
  --lerp: var(--lerp-3);
  z-index: 2;
}
.block:has( + .block + .block + .block + :is(.block:hover, .block:focus-visible)),
:is(.block:hover, .block:focus-visible) + .block + .block + .block + .block {
  --lerp: var(--lerp-4);
  z-index: 1;
}


body:has(a[style="--bg: var(--gradient-1);"]:focus) {
  background: var(--gradient-1);
}
body:has(a[style="--bg: var(--gradient-2);"]:focus) {
  background: var(--gradient-2);
}
body:has(a[style="--bg: var(--gradient-3);"]:focus) {
  background: var(--gradient-3);
}
body:has(a[style="--bg: var(--gradient-4);"]:focus) {
  background: var(--gradient-4);
}
body:has(a[style="--bg: var(--gradient-5);"]:focus) {
  background: var(--gradient-5);
}
body:has(a[style="--bg: var(--gradient-6);"]:focus) {
  background: var(--gradient-6);
}
body:has(a[style="--bg: var(--gradient-7);"]:focus) {
  background: var(--gradient-7);
}
body:has(a[style="--bg: var(--gradient-8);"]:focus) {
  background: var(--gradient-8);
}
body:has(a[style="--bg: var(--gradient-9);"]:focus) {
  background: var(--gradient-9);
}

// 404

/**
* Custom props generated from: https://codepen.io/jh3y/pen/ExEJMoR
*/