* {
  margin: 0;
  padding: 0;
  font-family: Roboto, "Helvetica Neue", Arial, sans-serif;
  font-weight: 900;
}
.container {
  position: relative;
  display: flex;
  height: 100vh;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  i {
    margin-top: 10px;
    color: #333;
  }
  span {
    width: 100%;
    height: 100%;
    background: #efefef;
    position: absolute;
    z-index: -1;
    transition: all 0.5s ease;
  }
  div {
    position: relative;
    width: auto;
    background: #1d1e21;
    color: #555;
    padding: 20px 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 46px;
    cursor: pointer;
    margin: 0 4px;
    border-radius: 25px;
    box-shadow: 0px 0px 5px rgba(0, 0, 0, 0.5);
    transition: all 0.5s ease;
  }
}

input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 100%;
  width: 100%;
  z-index: 100;
  &:checked {
    ~ {
      div {
        box-shadow: 0px 0px 5px rgba(255, 255, 255, 0.5);
        color: yellow;
        text-shadow: 0 0 15px yellow, 0 0 25px yellow;
        animation: glow 5s linear infinite;
      }
      span {
        background: #333;
      }
    }
  }
}

@keyframes glow {
  0% {
    filter: hue-rotate(0deg);
  }
  100% {
    filter: hue-rotate(360deg);
  }
}