:root {
  --ink: #172126;
  --muted: #667178;
  --line: #dce1e3;
  --page: #f7f8f8;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--page);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.5;
}

.shell {
  width: min(1400px, calc(100% - 48px));
  margin-inline: auto;
}

header {
  padding-block: 64px;
  color: white;
  background: #102d35;
}

h1 {
  max-width: 1150px;
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.5rem);
  line-height: 1.1;
  letter-spacing: -0.03em;
}

.authors {
  margin: 24px 0 0;
  color: #d3dcdf;
  font-size: 1.05rem;
}

.authors a {
  color: inherit;
  text-underline-offset: 3px;
}

.repo-link {
  display: inline-block;
  margin-top: 18px;
  color: white;
  font-weight: 700;
  text-underline-offset: 4px;
}

.speed-note {
  margin: 10px 0 0;
  color: rgba(211, 220, 223, 0.68);
  font-size: 0.76rem;
}

main {
  padding-block: 48px 80px;
}

section + section {
  margin-top: 72px;
}

h2 {
  margin: 0 0 24px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 36px 28px;
}

article {
  min-width: 0;
}

.video-grid article:last-child:nth-child(odd) {
  grid-column: 1 / -1;
  width: calc((100% - 28px) / 2);
  justify-self: center;
}

h3 {
  margin: 0 0 10px;
  font-size: 1.15rem;
}

.video-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: #000000;
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(14, 34, 40, 0.12);
}

.video-frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

@media (max-width: 760px) {
  .shell {
    width: min(100% - 28px, 1400px);
  }

  header {
    padding-block: 44px;
  }

  .authors {
    font-size: 0.95rem;
  }

  main {
    padding-block: 36px 60px;
  }

  .video-grid {
    grid-template-columns: 1fr;
  }

  .video-grid article:last-child:nth-child(odd) {
    grid-column: auto;
    width: 100%;
  }

}