:root{
  --btn-size: clamp(42px, 12vw, 60px);
  --btn-hover-width: clamp(110px, 40vw, 160px);
  --btn-hover-radius: calc(var(--btn-size) / 2);
  --btn-gap: clamp(10px, 3vw, 20px);
  --icon-size: clamp(20px, 5.5vw, 28px);
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: nowrap;
  gap: var(--btn-gap);
  min-height: 100dvh;
 
  background-color: #f5f5f5;
  font-family: 'Arial', sans-serif;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

body > div {
  display: none;
}

.button {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--btn-size);
  height: var(--btn-size);
  border-radius: 50%;
  background-color: white;
  color: gray;
  cursor: pointer;
  overflow: hidden;
  text-decoration: none;
  transition: width 0.5s ease, border-radius 0.5s ease;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  flex: 0 0 auto;
}

.button .material-icons {
  font-size: var(--icon-size);
  transition: transform 0.5s ease, opacity 0.3s ease;
}

.button .button-text {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  opacity: 0;
  font-weight: bold;
  white-space: nowrap;
  transition: opacity 0.3s ease, transform 0.5s ease;
}

.button:hover {
  width: var(--btn-hover-width);
  border-radius: var(--btn-hover-radius);
}

.button:hover .material-icons {
  transform: translateY(-50px) scale(0.5);
  opacity: 0;
}

.button:hover .button-text {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.AI {
  background: rgb(242, 13, 109);
  color: white;
}