html,
body {
  height: 100%;
  margin: 0;
  font-family: 'Noto Sans', sans-serif;
  font-size: 16px;
  overflow: hidden;
}

body {
  display: flex;
  flex-direction: column;
}

a {
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

header {
  width: 100%;
  padding: 0.5rem;
  background-color: #bbd8fc;
}

nav {
  ul {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: stretch;
    margin: 0;
    padding: 0;
    gap: 0.5rem;
    list-style: none;
    text-align: center;
  }

  li {
    margin: 0;
    display: flex;
  }

  a {
    border-radius: 0.5rem;
    background: #0f4c9f;
    padding: 0.5rem;
    transition: background-color 200ms, color 200ms;
  }
  a,
  a:visited {
    color: white;
  }
  a:hover {
    background: #0b3a7b;
    text-decoration: none;
  }
  a.selected {
    background: red;
  }
}

main {
  overflow-y: auto;
}

section {
  height: 100%;
  justify-content: center;
  font-size: 1.25rem;
  margin: auto;
  display: flex;
}

.content {
  padding: 1rem;
  width: 100%;
  overflow: hidden;

  @media (min-width: 640px) {
    & {
      width: 640px;
      font-size: 1.5rem;
    }
  }

  @media (min-width: 1024px) {
    & {
      width: 1024px;
      font-size: 1.75rem;
    }
  }
}

section:nth-of-type(1) {
  background-image: url('images/wave1.svg');
}
section:nth-of-type(2) {
  background-image: url('images/wave2.svg'), url('images/wave1.svg');
}
section:nth-of-type(3) {
  background-image: url('images/wave3.svg'), url('images/wave2.svg'), url('images/wave1.svg');
}
section:nth-of-type(4) {
  background-image: url('images/wave4.svg'), url('images/wave3.svg'), url('images/wave2.svg'), url('images/wave1.svg');
}
section:nth-of-type(5) {
  background-image: url('images/wave5.svg'), url('images/wave4.svg'), url('images/wave3.svg'), url('images/wave2.svg'),
    url('images/wave1.svg');
}
section:nth-of-type(6) {
  background-image: url('images/wave6.svg'), url('images/wave5.svg'), url('images/wave4.svg'), url('images/wave3.svg'),
    url('images/wave2.svg'), url('images/wave1.svg');
}
section:nth-of-type(7) {
  background-image: url('images/wave7.svg'), url('images/wave6.svg'), url('images/wave5.svg'), url('images/wave4.svg'),
    url('images/wave3.svg'), url('images/wave2.svg'), url('images/wave1.svg');
}
section:nth-of-type(8) {
  background-image: url('images/wave8.svg'), url('images/wave7.svg'), url('images/wave6.svg'), url('images/wave5.svg'),
    url('images/wave4.svg'), url('images/wave3.svg'), url('images/wave2.svg'), url('images/wave1.svg');
}

.start-work {
  display: block;
  width: max-content;
  margin: 3rem auto;
  padding: 0.5rem 1.5rem;
  border-radius: 0.5rem;
  background: #ff8512;
  transition: background-color 200ms, color 200ms;
}
.start-work,
.start-work:visited {
  color: #000;
}
.start-work:hover {
  background: #f07705;
  color: #000;
  text-decoration: none;
}

.roadmap-timeline {
  display: flex;
  align-items: stretch;
  text-align: center;
  margin-bottom: 1rem;
  background: linear-gradient(to right, rgba(0 0 0 / 0.1) 0%, #0f4c9f 20%, #0f4c9f 80%, rgba(0 0 0 / 0.1) 100%);
  background-size: 100% 4px;
  background-position: 0 9px;
  background-repeat: no-repeat;
  mask-image: linear-gradient(
    to right,
    rgba(0 0 0 / 0.2) 0%,
    rgba(0 0 0 / 1) 30%,
    rgba(0 0 0 / 1) 70%,
    rgba(0 0 0 / 0.2) 100%
  );
  user-select: none;

  label {
    flex: 1;
    position: relative;
    font-size: 0.75em;
    cursor: pointer;
    padding-top: 1.5rem;
  }
  label:before {
    content: '';
    position: absolute;
    display: block;
    width: 16px;
    height: 16px;
    top: 3px;
    left: calc(50% - 8px);
    border-radius: 50%;
    background: #0f4c9f;
    transition: all 100ms;
  }
  label:hover:before,
  label.selected:hover:before {
    background: #f07705;
  }
  label.selected:before {
    background: #ff8512;
    outline: 3px solid #0f4c9f;
  }
}

.roadmap-item {
  display: grid;
  grid-template-columns: 5em 1fr;
  transform-origin: top;
  transform: scaleY(0);
  height: 0;
  opacity: 0.4;
  overflow: hidden;
  pointer-events: none;
  transition: all 500ms;
  interpolate-size: allow-keywords;

  input {
    display: none;
  }

  h3,
  p {
    margin: 0.5rem 0;
  }

  h3 {
    font-size: inherit;
    font-weight: inherit;
  }
}

.roadmap-item:has(+ .roadmap-item input:checked),
.roadmap-item:has(input:checked),
.roadmap-item:has(input:checked) + .roadmap-item {
  transform: scaleY(1);
  height: auto;
}

.roadmap-item:has(input:checked) {
  opacity: 1;
}

.roadmap-item:has(~ .roadmap-item input:checked) {
  mask-image: linear-gradient(to top, rgba(0 0 0 / 1) 0%, rgba(0 0 0 / 0) 100%);
}

.roadmap-item:has(input:checked) ~ .roadmap-item {
  mask-image: linear-gradient(to bottom, rgba(0 0 0 / 1) 0%, rgba(0 0 0 / 0) 100%);
}