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

body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: #333;
}

.buttons {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  min-width: 140px;
  gap: 20px;
}

.buttons label {
  position: relative;
  width: 60px;
  height: 60px;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
}

.buttons label input {
  appearance: none;
}

.buttons label span {
  position: absolute;
  width: 100%;
  height: 100%;
  background: linear-gradient(#555353, #363535, #303030);
  border: 2px solid #222;
  border-radius: 6px;
  box-shadow: inset 0 5px 1px rgba(0, 0, 0, 0.35), 0 5px 5px rgba(0, 0, 0, 0.5),
    0 15px 25px rgba(0, 0, 0, 0.35);
}

.buttons label span:checked ~ span {
  box-shadow: inset 0 2px 2px rgba(0, 0, 0, 0.35),
    inset 0 5px 5px rgba(0, 0, 0, 0.5), inset 0 15px 25px rgba(0, 0, 0, 0.35);
}

.buttons label span::before {
  content: "";
  position: absolute;
  inset: 5px 3px;
  border-top: 1px solid #ccc;
  filter: blur(2px);
}

.buttons label i {
  position: relative;
  z-index: 10;
  font-size: 1.5em;
  color: #111;
}

.buttons label input:checked ~ i {
  color: #fff;
  text-shadow: 0 0 5px #219cf3, 0 0 8px #219cf3;
}