html, body {
  height: 100%;
  font-family: monospace;
  margin: 0;
  padding: 0;
}

.container {
  width: 100%;
  height: 100%;
  display: -webkit-box;
  display: flex;
  -webkit-box-pack: center;
          justify-content: center;
  -webkit-box-align: center;
          align-items: center;
}

.source {
  position: fixed;
  right: 2rem;
  bottom: 2rem;
}
.source a {
  color: #fff;
  text-decoration: none;
}
.source a span {
  opacity: 0.32;
}

.phone {
  display: -webkit-box;
  display: flex;
  width: 25em;
  height: 25em;
  background-color: #f3f3f3;
  border-radius: 32px;
  overflow: hidden;
}

.phone-footer {
  display: -webkit-box;
  display: flex;
  -webkit-box-pack: center;
          justify-content: center;
  -webkit-box-align: center;
          align-items: center;
  width: 100%;
  height: 6em;
  padding-left: 2em;
  padding-right: 2em;
  background-color: #fff;
  margin-top: auto;
}

.nav {
  display: -webkit-box;
  display: flex;
  width: 100%;
  -webkit-box-pack: justify;
          justify-content: space-between;
}
.nav-item {
  position: relative;
  display: -webkit-box;
  display: flex;
  padding: 8px;
  border-radius: 16px;
}
.nav-item:nth-child(1) {
  background-color: #e8e2f6;
}
.nav-item:nth-child(1) label {
  background-color: #5b37b7;
}
.nav-item:nth-child(1) span {
  color: #5b37b7;
}
.nav-item:nth-child(1) span:before {
  background-color: #5b37b7;
}
.nav-item:nth-child(2) {
  background-color: #f6e3f1;
}
.nav-item:nth-child(2) label {
  background-color: #b73892;
}
.nav-item:nth-child(2) span {
  color: #b73892;
}
.nav-item:nth-child(2) span:before {
  background-color: #b73892;
}
.nav-item:nth-child(3) {
  background-color: #fff3d9;
}
.nav-item:nth-child(3) label {
  background-color: #eda600;
}
.nav-item:nth-child(3) span {
  color: #eda600;
}
.nav-item:nth-child(3) span:before {
  background-color: #eda600;
}
.nav-item:nth-child(4) {
  background-color: #afedf7;
}
.nav-item:nth-child(4) label {
  background-color: #1194aa;
}
.nav-item:nth-child(4) span {
  color: #1194aa;
}
.nav-item:nth-child(4) span:before {
  background-color: #1194aa;
}
.nav-item * {
  cursor: pointer;
}
.nav-item label {
  position: relative;
  display: inline-block;
  width: 1em;
  height: 1em;
  background-color: inherit;
  border-radius: 50%;
}
.nav-item label:before {
  content: "";
  position: absolute;
  top: -100%;
  left: -100%;
  width: 300%;
  height: 300%;
  background-color: transparent;
}
.nav-item span {
  font-size: 0.875em;
  margin-left: 0;
  max-width: 0;
  overflow: hidden;
  -webkit-transition-property: max-width, margin-left;
  transition-property: max-width, margin-left;
  -webkit-transition-duration: 0.32s;
          transition-duration: 0.32s;
  -webkit-transition-timing-function: ease;
          transition-timing-function: ease;
}
.nav-item span:before {
  content: "";
  opacity: 0;
  position: fixed;
  z-index: -1;
  top: 50%;
  margin-top: -100rem;
  left: 50%;
  margin-left: -100rem;
  width: 200rem;
  height: 200rem;
  -webkit-transform-origin: center;
          transform-origin: center;
  -webkit-transform: scale(0.1);
          transform: scale(0.1);
  border-radius: 50%;
  -webkit-transition-property: opacity, -webkit-transform;
  transition-property: opacity, -webkit-transform;
  transition-property: opacity, transform;
  transition-property: opacity, transform, -webkit-transform;
  -webkit-transition-duration: 0.32s;
          transition-duration: 0.32s;
  -webkit-transition-timing-function: ease;
          transition-timing-function: ease;
}
.nav-item input {
  position: absolute;
  top: 0;
  left: 0;
  visibility: hidden;
}
.nav-item input:checked + span {
  max-width: 100vw;
  margin-left: 4px;
}
.nav-item input:checked + span:before {
  opacity: 1;
  -webkit-transform: scale(1);
          transform: scale(1);
}