html,
body {
  height: 100%;
}

body {
  background: black;
}

* {
  touch-action: none;
}

.container {
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

.countdown {
  display: block;
  width: 66vmin;
  height: 66vmin;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: "Oswald", sans-serif;
  font-weight: 400;
  font-size: 25vmin;
  border-radius: 50%;
  overflow: hidden;
  cursor: pointer;
  transition: width, height, border-radius, font-size;
  transition-duration: 0.2s;
}
.countdown--ended {
  -webkit-animation: buzz 0.5s;
          animation: buzz 0.5s;
}
.countdown:active {
  transform: scale(1.02);
}
@-webkit-keyframes buzz {
  0% {
    transform: rotate(0);
  }
  10%, 30%, 50%, 70%, 90% {
    transform: rotate(6deg);
  }
  20%, 40%, 60%, 80% {
    transform: rotate(-6deg);
  }
  100% {
    transform: rotate(0);
  }
}
@keyframes buzz {
  0% {
    transform: rotate(0);
  }
  10%, 30%, 50%, 70%, 90% {
    transform: rotate(6deg);
  }
  20%, 40%, 60%, 80% {
    transform: rotate(-6deg);
  }
  100% {
    transform: rotate(0);
  }
}
.countdown--wide {
  width: 100%;
  height: 100%;
  font-size: 50vmin;
  border-radius: 0;
}
.countdown__fill {
  display: block;
  width: 100%;
  height: 100%;
  position: absolute;
  left: 0;
  bottom: 0;
  background: #FF5722;
  opacity: 1;
}
.countdown__digit {
  width: 100%;
  color: #FF5722;
  text-align: center;
  mix-blend-mode: difference;
  pointer-events: none;
  -webkit-user-select: none;
     -moz-user-select: none;
      -ms-user-select: none;
          user-select: none;
}
.countdown__buttons {
  position: absolute;
  right: 50px;
  top: 50%;
  height: 200px;
  margin-top: -100px;
  color: white;
  z-index: 1;
}
.countdown__button {
  height: 50%;
}

.full-button {
  position: absolute;
  right: 10px;
  bottom: 10px;
  padding: 1em 0.5em 0.5em 2em;
  font-family: "Oswald", sans-serif;
  text-transform: uppercase;
  color: white;
  cursor: pointer;
}