:root {
  color-scheme: light;
  --ink: #10263d;
  --muted: #607182;
  --line: #c9d6de;
  --panel: #f5f8fa;
  --paper: #ffffff;
  --teal: #008b8b;
  --blue: #006fb8;
  --accent: #f2c230;
}

* {
  box-sizing: border-box;
}

html {
  background: #eaf0f4;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: "Avenir Next", Avenir, "Segoe UI", sans-serif;
  background:
    linear-gradient(90deg, rgba(0, 111, 184, 0.08) 1px, transparent 1px),
    linear-gradient(rgba(0, 139, 139, 0.07) 1px, transparent 1px),
    linear-gradient(180deg, #fbfcfd 0%, #e8f0f5 100%);
  background-size: 32px 32px, 32px 32px, auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 5;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 18px;
  align-items: center;
  padding: 18px clamp(16px, 4vw, 44px);
  border-bottom: 1px solid rgba(16, 38, 61, 0.14);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(18px);
}

.mark {
  width: 18px;
  height: 52px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--teal), var(--blue) 68%, var(--accent) 68%);
}

.module {
  margin: 0 0 4px;
  color: var(--teal);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(1.22rem, 2.2vw, 2rem);
  line-height: 1.04;
}

.subtitle {
  margin: 5px 0 0;
  max-width: 740px;
  color: var(--muted);
  font-size: clamp(0.82rem, 1.35vw, 0.98rem);
  line-height: 1.35;
}

.actions {
  display: flex;
  gap: 10px;
  align-items: center;
}

.button {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  padding: 0 15px;
  border: 1px solid rgba(16, 38, 61, 0.22);
  border-radius: 6px;
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 800;
  text-decoration: none;
  background: var(--paper);
  box-shadow: 0 1px 0 rgba(16, 38, 61, 0.08);
}

.button.primary {
  border-color: var(--teal);
  color: #ffffff;
  background: linear-gradient(135deg, var(--teal), var(--blue));
}

.button:focus-visible,
.poster-shell a:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

main {
  padding: clamp(14px, 3vw, 36px);
}

.poster-shell {
  width: min(100%, 1120px);
  margin: 0 auto;
  border: 1px solid rgba(16, 38, 61, 0.16);
  border-radius: 8px;
  overflow: hidden;
  background: var(--paper);
  box-shadow: 0 20px 70px rgba(16, 38, 61, 0.16);
}

.poster-shell a {
  display: block;
}

.poster-shell img {
  display: block;
  width: 100%;
  height: auto;
}

@media (max-width: 760px) {
  .site-header {
    position: static;
    grid-template-columns: auto minmax(0, 1fr);
  }

  .actions {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .button {
    padding: 0 10px;
  }
}