*,*:before,*:after {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: 'Montserrat', sans-serif;
  font-size: 18px; /* 1rem = 18px */
  line-height: 1.15;
  -ms-text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: #000;
  color: #FFFFFF;
  margin: 0;
  padding: 1rem;
  transition: background-color .5s ease, color .5s ease;
}

article, aside, main, footer {
  display: block;
}

a {
  background-color: transparent;
  color: inherit;
  cursor: pointer;;
  position: relative;
  text-decoration: none;
}

a:active,
a:hover {
  outline-width: 0;
}

a::after {
  position: absolute;
  top: 85%;
  left: 50%;
  color: transparent;
  content: '•';
  font-size: .8rem;
  transform: translateX(-50%);
  transition: color 0.3s;
}

a:hover::after {
  color: inherit;
}

header a.title {
  font-weight: bold;
}

header aside#previous-wrapper {
  font-size: .9rem;
}

header a#previous-color {
  font-size: 1rem;
}

header aside#previous-wrapper {
  float: right;;
}

header a#previous-color {
  display: inline-block;
  min-width: 5rem;
  text-align: center;
}

main, aside#intro {
  position: fixed;
  left: 50%;
  opacity: 1;
  text-align: center;
  top: 50%;
  transform: translate(-50%, -50%);
}

aside#intro p {
  font-size: 1.2rem;
}

.hidden {
  opacity: 0 !important;
}

main h1 {
  cursor: pointer;
  font-size: 2.5rem;
  font-weight: lighter;
  letter-spacing: .1rem;
  margin: 1rem 0;
  position: relative;
  transition: opacity 0.5s ease;
}

main h1::after {
  bottom: -1.2rem;
  content: attr(data-tooltip);
  font-size: .6rem;
  left: 0;
  opacity: 0;
  position: absolute;
  transition: opacity 0.5s ease;
  width: 100%;
}

main:hover h1::after {
  opacity: .6;
}

main h1.changed::after {
  opacity: 0 !important;
}

main h2 {
  cursor: pointer;
  font-size: 1rem;
  font-weight: lighter;
  letter-spacing: .1rem;
  margin-top: 2rem;
}

footer {
  bottom: 0;
  left: 0;
  position: absolute;
  text-align: center;
  width: 100%;
}

footer p.credits {
  font-size: 0.6rem;
  margin-bottom: .5rem;
  width: 100%;
}

/* Media queries, mobile only */
@media only screen and (max-device-width : 736px) {
  html {
    font-size: 16px;
  }

  main h1::after {
    opacity: .5 !important;
  }
}