body {
  margin: 0;
  background: #333;
  overflow: hidden;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

#phone {
  width: 320px;
  height: 480px;
  background: white;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.25), 0 0 2px rgba(0, 0, 0, 0.2) inset;
  position: relative;
  overflow: hidden;
  background: #8db6ff;
  -webkit-user-select: none;
  user-select: none;
  box-shadow: 0 0 1px inset rgba(0, 0, 0, 0.5);
  border-radius: 2px;
}

/** When the screen is small, go full-screen */
@media (max-width: 600px) {
  #phone {
    width: 100vw;
    height: 100vh;
    box-shadow: none;
    border-radius: 0;
  }
}

.ball {
  border-radius: 1000px;
  background: #f44336;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.33);
  height: 64px;
  width: 64px;
  color: white;
  position: relative;
  will-change: transform;
  transform: translateZ(0);
}

.ball i {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  text-align: center;
  line-height: 64px !important;
  font-size: 38px !important;
}

.icons {
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
}
.icons .ball {
  margin: 16px 12px;
}

#main {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
}

#cover {
  position: absolute;
  top: calc(100% - (64px + 16px + 16px));
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.5);
  box-shadow: 0 0 4px rgba(0, 0, 0, 0.125);
  cursor: n-resize;
  will-change: transform;
  transform: translateZ(0);
}