@import url('https://fonts.googleapis.com/css2?family=Vazirmatn:wght@400;500;600;700;800&display=swap');

:root {
  color-scheme: light;
  --navy: #123b5d;
  --blue: #176b87;
  --teal: #159a91;
  --ink: #193247;
  --muted: #718392;
  --line: #e3ebef;
  --surface: #ffffff;
  --background: #f2f7f9;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Vazirmatn", Tahoma, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% 5%, rgba(21,154,145,.10), transparent 28rem),
    linear-gradient(135deg, #f4f8fa, #edf4f7);
}

.page {
  width: min(920px, calc(100% - 32px));
  margin: 48px auto 28px;
}

.header {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 26px 30px;
  color: white;
  border-radius: 22px;
  background: linear-gradient(120deg, #123b5d, #176b87);
  box-shadow: 0 16px 38px rgba(18,59,93,.16);
}

.brand-mark {
  display: grid;
  place-items: center;
  flex: 0 0 62px;
  height: 62px;
  border: 1px solid rgba(255,255,255,.35);
  border-radius: 18px;
  background: rgba(255,255,255,.13);
  font-size: 25px;
}

.eyebrow {
  margin: 0 0 3px;
  color: #b9e7e4;
  font-size: 13px;
}

h1 {
  margin: 0;
  font-size: clamp(23px, 4vw, 31px);
  font-weight: 800;
}

.subtitle {
  margin: 5px 0 0;
  color: rgba(255,255,255,.78);
  font-size: 14px;
}

.content {
  margin-top: 24px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: 0 12px 34px rgba(29,67,88,.06);
}

.content > h2 {
  margin: 0;
  font-size: 20px;
}

.description {
  margin: 7px 0 20px;
  color: var(--muted);
  font-size: 14px;
}

.video-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 24px;
}

.video-button {
  min-height: 48px;
  border: 1px solid #dce7ec;
  border-radius: 12px;
  color: var(--navy);
  background: #f7fafb;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  transition: .18s ease;
}

.video-button:hover {
  border-color: var(--teal);
  transform: translateY(-1px);
}

.video-button.active {
  border-color: transparent;
  color: white;
  background: linear-gradient(110deg, var(--blue), var(--teal));
  box-shadow: 0 7px 16px rgba(21,154,145,.2);
}

.player-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 17px;
  background: #fbfdfe;
}

.player-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 17px 20px;
}

.now-playing {
  color: var(--teal);
  font-size: 12px;
  font-weight: 700;
}

.player-heading h2 {
  margin: 2px 0 0;
  font-size: 18px;
}

.video-number {
  padding: 6px 10px;
  border-radius: 8px;
  color: var(--blue);
  background: #eaf4f6;
  direction: ltr;
  font-size: 12px;
  font-weight: 700;
}

.video-frame {
  position: relative;
  background: #07131d;
  aspect-ratio: 16 / 9;
}

video {
  display: block;
  width: 100%;
  height: 100%;
  max-height: 560px;
  aspect-ratio: 16 / 9;
  background: #07131d;
}

.error-message {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 24px;
  color: white;
  background: #142b3b;
  text-align: center;
  line-height: 1.9;
}

.error-message[hidden] { display: none; }

.error-message a {
  color: #9ce9df;
  font-weight: 700;
}

.hint {
  margin: 0;
  padding: 13px 18px 16px;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.9;
}

.footer {
  padding: 18px 8px;
  color: #81919b;
  text-align: center;
  font-size: 12px;
}

@media (max-width: 600px) {
  .page { width: min(100% - 20px, 920px); margin-top: 18px; }
  .header { padding: 20px; border-radius: 17px; }
  .brand-mark { flex-basis: 52px; height: 52px; border-radius: 15px; }
  .content { margin-top: 14px; padding: 19px 14px; border-radius: 17px; }
  .video-tabs { gap: 7px; }
  .video-button { min-height: 45px; }
  .player-heading { padding: 14px; }
}