body, html {
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

h1.timer {
  font-size: 10em;
  text-align: center;
  margin: 0;
  padding: 0;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: #fff;
  text-shadow: 0px 4px 1px rgba(0, 0, 0, 0.3);
  display: none;
}

.visible {
  display: block !important;
}

button {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: none;
}

.background {
  transition: all .3s;
  filter: blur(0);
  position: absolute;
  z-index: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

.background div {
  display: block;
  position: absolute;
  width: calc(100% + 30px);
  height: calc(100% + 30px);
  transition: all .3s;
  margin: -15px;
  background: url('/assets/img/pedro-lastra-5g8dJvtYRYA-unsplash.jpg') no-repeat center center;
  background-size: cover;
}

.blurred-container {
  opacity: 1;
}

.blurred-container div {
  filter: blur(8px);
}