Creepy Button | Learning Axis

HTML

CSS

* {
  border: 0;
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
:root {
  --hue: 223deg;
  --gray1: hsl(var(--hue) 10% 90%);
  --gray9: hsl(var(--hue) 10% 15%);
  --black: hsl(0 0% 0%);
  --primary3: hsl(var(--hue) 90% 75%);
  --primary5: hsl(var(--hue) 90% 55%);
  --primary6: hsl(var(--hue) 90% 45%);
  --trans-dur: 0.3s;
  font-size: clamp(1.25rem, 1rem + 1.25vw, 2.5rem);
}
body {
  font: 1em / 1.5 "Londrina Solid", sans-serif;
  transition: background-color var(--trans-dur), color var(--trans-dur);
  background-color: var(--gray1);
  color: var(--gray9);
  display: grid;
  place-items: center;
  height: 100vh;
}
.creepy-btn {
  background-color: var(--black);
  border-radius: 1.25em;
  color: var(--gray1);
  cursor: pointer;
  letter-spacing: 1px;
  min-width: 9em;
  transition: outline 0.1s linear;
  -webkit-tap-highlight-color: transparent;
  position: relative;
  font-size: 1rem;
}
.creepy-btn__cover {
  background-color: var(--primary5);
  border-radius: inherit;
  display: block;
  padding: 0.5em 1em;
  inset: 0;
  position: relative;
  z-index: 999;
  transform-origin: 1.25em 50%;
  transition: background-color var(--trans-dur), transform var(--trans-dur) cubic-bezier(0.65,0,0.35,1);
}
.creepy-btn:hover .creepy-btn__cover {
  background-color: var(--primary6);
}
.creepy-btn:focus-visible {
  outline: 0.1875em solid var(--primary3);
}
.creepy-btn:focus-visible .creepy-btn__cover,
.creepy-btn:hover .creepy-btn__cover {
  transform: rotate(-17deg);
  transition-timing-function: cubic-bezier(0.65,0,0.35,1.65);
}
.creepy-btn:active .creepy-btn__cover {
  transform: rotate(0);
  transition-timing-function: cubic-bezier(0.65,0,0.35,1);
}
.creepy-btn__eyes {
  position: absolute;
  right: 1em;
  bottom: 0.5em;
  display: flex;
  align-items: center;
  gap: 0.375em;
  height: 0.75em;
  z-index: 2;
}
.creepy-btn__eye {
  width: 0.75em;
  height: 0.75em;
  background-color: var(--gray1);
  border-radius: 50%;
  overflow: hidden;
  position: relative;
  animation: eye-blink 3s infinite;
}
.creepy-btn__pupil {
  width: 0.375em;
  aspect-ratio: 1;
  background-color: var(--black);
  border-radius: inherit;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  transition: transform 0.05s;
}
@keyframes eye-blink {
  0%, 92%, 100% { height: 0.75em; }
  96% { height: 0; }
}