:root {
  color-scheme: light;
  --ink: #161719;
  --muted: #62666d;
  --paper: #f4f4f2;
  --panel: #ffffff;
  --line: #d8d7d1;
  --accent: #ec5f36;
  --accent-dark: #ab381e;
  --green: #1a8b6e;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
}

body {
  margin: 0;
  min-height: 100%;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.82), rgba(244, 244, 242, 0.96)),
    var(--paper);
  color: var(--ink);
  font-family: "Sora", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.video-page {
  min-height: 100svh;
  display: grid;
  grid-template-rows: auto 1fr;
  padding: clamp(18px, 4vw, 48px);
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  width: min(980px, 100%);
  max-width: calc(100vw - 36px);
  margin: 0 auto;
  color: var(--muted);
  font-size: clamp(0.78rem, 1.8vw, 0.94rem);
  font-weight: 700;
  text-transform: uppercase;
}

.brand-mark {
  display: block;
  width: clamp(156px, 24vw, 240px);
  height: auto;
}

.player-wrap {
  width: min(980px, 100%);
  max-width: calc(100vw - 36px);
  margin: 0 auto;
  display: grid;
  align-content: center;
  gap: clamp(18px, 3vw, 28px);
  padding: clamp(22px, 5vh, 48px) 0;
}

.video-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(236, 95, 54, 0.16), transparent 36%),
    #202226;
  box-shadow: 0 24px 56px rgba(22, 23, 25, 0.16);
}

video {
  display: block;
  width: 100%;
  height: 100%;
  background: #202226;
}

#streamPlayer {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  background: #202226;
}

.video-placeholder {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  gap: 12px;
  padding: clamp(20px, 5vw, 44px);
  color: #fff;
  text-align: center;
  background:
    linear-gradient(135deg, rgba(26, 139, 110, 0.32), transparent 42%),
    #202226;
}

.video-placeholder p {
  max-width: 560px;
  margin: 0 auto;
  color: rgba(255, 255, 255, 0.78);
  font-size: clamp(0.95rem, 2vw, 1.1rem);
  line-height: 1.55;
}

.eyebrow {
  margin: 0;
  color: var(--green);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(1.45rem, 3vw, 2.5rem);
  line-height: 1.08;
  font-weight: 800;
  text-align: center;
}

.back-link {
  justify-self: center;
  color: var(--green);
  font-size: 0.82rem;
  font-weight: 800;
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.lesson-nav {
  display: grid;
  gap: 12px;
  margin-top: clamp(4px, 1vw, 10px);
}

.lesson-nav-title {
  margin: 0;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-align: center;
  text-transform: uppercase;
}

.lesson-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.lesson-link {
  min-width: 0;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  align-items: center;
  padding: 13px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  color: var(--ink);
  text-decoration: none;
}

.lesson-link:hover,
.lesson-link:focus-visible {
  border-color: rgba(26, 139, 110, 0.52);
  outline: none;
}

.lesson-link.active {
  border-color: rgba(26, 139, 110, 0.74);
  background: rgba(26, 139, 110, 0.1);
}

.lesson-number {
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 6px;
  background: var(--ink);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 800;
}

.lesson-link.active .lesson-number {
  background: var(--green);
}

.lesson-title {
  overflow: hidden;
  color: currentColor;
  font-size: 0.9rem;
  font-weight: 800;
  line-height: 1.2;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.qr-page {
  min-height: 100svh;
  padding: clamp(18px, 4vw, 48px);
}

.qr-wrap {
  width: min(1120px, 100%);
  margin: 0 auto;
  display: grid;
  gap: 28px;
}

.qr-hero {
  display: grid;
  gap: 12px;
  padding-top: clamp(20px, 6vw, 52px);
}

.qr-hero h1 {
  max-width: 760px;
  text-align: left;
}

.qr-hero p {
  max-width: 720px;
  margin: 0;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.6;
}

.qr-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.qr-card {
  min-width: 0;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  align-items: center;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.qr-code {
  width: 112px;
  height: 112px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f4f4f2;
  overflow: hidden;
}

.qr-code img {
  display: block;
  width: 100%;
  height: 100%;
}

.qr-meta {
  min-width: 0;
  display: grid;
  gap: 7px;
}

.qr-meta h2 {
  margin: 0;
  color: var(--ink);
  font-size: 1rem;
  line-height: 1.15;
}

.qr-meta p,
.qr-meta code {
  margin: 0;
  color: var(--muted);
  font-size: 0.76rem;
  line-height: 1.45;
}

.qr-meta code {
  display: block;
  overflow-wrap: anywhere;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.qr-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 4px;
}

.button-link {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 8px 12px;
  border-radius: 6px;
  background: var(--ink);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-decoration: none;
  text-transform: uppercase;
}

.button-link.secondary {
  background: rgba(26, 139, 110, 0.12);
  color: var(--green);
}

@media (max-width: 640px) {
  .video-page {
    padding: 18px;
  }

  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .player-wrap {
    align-content: start;
    padding-top: 44px;
  }

  .lesson-grid,
  .qr-grid,
  .qr-card {
    grid-template-columns: 1fr;
  }

  .qr-code {
    width: 100%;
    height: auto;
    aspect-ratio: 1;
    max-width: 180px;
  }

}