:root {
  color-scheme: dark;
  --bg: #0b0d10;
  --panel: #12161d;
  --panel-2: #181f29;
  --text: #e9edf3;
  --text-soft: #9ea7b5;
  --brand: #4d8dff;
  --border: #263040;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Inter", system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color: var(--text);
  background: radial-gradient(circle at 10% -10%, #1d2d46 0%, var(--bg) 35%);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 22px;
  background: rgba(11, 13, 16, 0.88);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.brand {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.2px;
}

.search {
  flex: 1;
}

.search input {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--panel);
  color: var(--text);
  padding: 11px 14px;
  font-size: 0.95rem;
}

.search input::placeholder {
  color: var(--text-soft);
}

.upload-btn {
  border: 0;
  border-radius: 10px;
  background: var(--brand);
  color: #fff;
  padding: 10px 16px;
  font-weight: 600;
  cursor: pointer;
}

.layout {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 20px;
  max-width: 1300px;
  margin: 0 auto;
  padding: 20px;
}

.sidebar {
  position: sticky;
  top: 78px;
  height: fit-content;
  background: rgba(18, 22, 29, 0.8);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 10px;
}

.nav-item {
  display: block;
  color: var(--text-soft);
  text-decoration: none;
  padding: 10px 12px;
  border-radius: 10px;
  font-size: 0.94rem;
}

.nav-item:hover,
.nav-item.active {
  color: var(--text);
  background: var(--panel-2);
}

.content {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.hero-card {
  background: linear-gradient(145deg, rgba(26, 33, 46, 0.9), rgba(18, 22, 29, 0.8));
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 16px;
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(280px, 1fr);
  gap: 18px;
}

.hero-video {
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border-radius: 12px;
  border: 1px solid var(--border);
}

.hero-video iframe {
  width: 100%;
  height: 100%;
  border: 0;
}

.hero-info {
  display: flex;
  flex-direction: column;
  gap: 10px;
  justify-content: center;
}

.tag {
  width: fit-content;
  font-size: 0.78rem;
  color: #c7ddff;
  border: 1px solid #5d82bf;
  border-radius: 999px;
  padding: 5px 10px;
}

.hero-info h1 {
  margin: 0;
  font-size: 1.5rem;
}

.hero-info p {
  margin: 0;
  line-height: 1.6;
  color: var(--text-soft);
}

.video-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.video-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.video-card:hover {
  transform: translateY(-2px);
  border-color: #3f5374;
}

.thumb-wrap {
  position: relative;
  aspect-ratio: 16 / 9;
  background: #1d2532;
}

.thumb {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.duration {
  position: absolute;
  right: 8px;
  bottom: 8px;
  font-size: 0.76rem;
  color: #fff;
  background: rgba(0, 0, 0, 0.72);
  border-radius: 6px;
  padding: 3px 6px;
}

.video-title {
  margin: 10px 12px 6px;
  font-size: 1rem;
}

.video-meta {
  margin: 0 12px 12px;
  color: var(--text-soft);
  font-size: 0.86rem;
}

@media (max-width: 980px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    display: flex;
    gap: 8px;
    overflow-x: auto;
  }

  .nav-item {
    white-space: nowrap;
  }

  .hero-card {
    grid-template-columns: 1fr;
  }

  .video-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .topbar {
    padding: 12px;
  }

  .upload-btn {
    display: none;
  }

  .layout {
    padding: 12px;
  }

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