:root {
  --background: #ffffff;
  --surface: #ffffff;
  --text: #20242a;
  --muted: #66707a;
  --border: #dfe3e8;
  --accent: #245b8a;
  --accent-dark: #173d5e;
  --soft: #f5f7f9;
  --radius: 8px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  background: var(--background);
  color: var(--text);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.55;
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

.link-bar {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 18px 0;
  display: grid;
  gap: 14px;
}

.link-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
}

.group-label {
  color: var(--text);
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
}

.link-group a {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  color: var(--accent-dark);
  font-size: .9rem;
  text-decoration: none;
}

.link-group a:hover,
.link-group a:focus-visible {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.icon {
  display: inline-grid;
  place-items: center;
  width: 20px;
  height: 20px;
  border-radius: 4px;
  font-size: .76rem;
  font-weight: 700;
  line-height: 1;
}

.web {
  border: 1px solid #aeb8c2;
  color: #53606c;
}

.facebook {
  background: #1877f2;
  color: #ffffff;
  font-family: Arial, sans-serif;
}

.matriochka {
  border: 1px solid #8c98a3;
  color: #39434c;
  background: #f3f5f6;
}

main {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.intro {
  max-width: 820px;
  margin: 0 auto;
  padding: 72px 0 46px;
  text-align: center;
}

h1 {
  margin: 0;
  color: #171a1e;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2.1rem, 5vw, 4.2rem);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -.025em;
}

.intro p {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 1.05rem;
}

.videos {
  padding: 0 0 80px;
  display: grid;
  gap: 34px;
}

.video-card {
  width: min(100%, 780px);
  margin: 0 auto;
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}

.video-card h2 {
  margin: 0 0 14px;
  color: #30363c;
  font-size: .95rem;
  font-weight: 700;
  letter-spacing: .03em;
  text-transform: uppercase;
}

video {
  display: block;
  width: 100%;
  max-height: 440px;
  border: 1px solid #cfd5db;
  border-radius: 4px;
  background: #000000;
}

.source-link {
  display: inline-block;
  margin-top: 14px;
  color: var(--accent-dark);
  font-size: .9rem;
  overflow-wrap: anywhere;
  text-underline-offset: 3px;
}

.source-link:hover,
.source-link:focus-visible {
  color: var(--accent);
}

.file-note {
  margin: 14px 0 0;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--soft);
  color: #505a64;
  font-size: .88rem;
}

code { overflow-wrap: anywhere; }

footer {
  padding: 28px 16px 36px;
  border-top: 1px solid var(--border);
  color: #4d5660;
  text-align: center;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.05rem;
}

footer p { margin: 0; }
footer span { padding: 0 .4em; }

@media (min-width: 920px) {
  .link-bar {
    grid-template-columns: 1fr auto;
    align-items: start;
  }

  .social-group { justify-content: flex-end; }
}

@media (max-width: 560px) {
  .link-bar,
  main {
    width: min(100% - 20px, 1120px);
  }

  .group-label {
    width: 100%;
    margin-top: 4px;
  }

  .intro { padding: 52px 0 36px; }
  .videos { gap: 22px; padding-bottom: 56px; }
  .video-card { padding: 12px; }
  video { max-height: 62vh; }
}