.header {
  position: relative;
  background: #00bcd4;
  height: 49px;
  padding-left: 10px;
  color: #fff;
  font-weight: bold;
  line-height: 49px;
  font-size: 30px;
}

.header .button {
  width: 28px;
  height: 28px;
  padding: 0;
  background-image: linear-gradient(transparent 9px, #fff 9px, #fff 11px, transparent 11px), linear-gradient(90deg, transparent 9px, #fff 9px, #fff 11px, transparent 11px);
  background-repeat: no-repeat;
  background-color: #5a5a5a52;
  background-clip: content-box;
  border-radius: 50%;
    border: 4px solid #5a5a5a52;
  vertical-align: middle;
  font-size: 0;
  color: transparent;
}