:root {
  --bg: #f7f7f9;
  --surface: #ffffff;
  --text: #14141a;
  --text-muted: #5c5c66;
  --border: #e2e2e8;
  --accent: #cc0000;
  --accent-hover: #a50000;
  --focus: #4a90d9;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f0f12;
    --surface: #1a1a1f;
    --text: #f0f0f2;
    --text-muted: #a0a0aa;
    --border: #2c2c33;
    --accent: #ff4d4d;
    --accent-hover: #ff7373;
    --focus: #6fb1f0;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  position: sticky;
  top: 0;
  z-index: 10;
}

.logo {
  margin: 0;
  font-size: 1.5rem;
  letter-spacing: -0.02em;
}

.logo::before {
  content: "▶ ";
  color: var(--accent);
}

.auth-area {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.btn {
  font: inherit;
  border-radius: 999px;
  padding: 0.5rem 1.1rem;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.btn:hover {
  border-color: var(--accent);
}

.btn:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.btn-ghost {
  background: transparent;
}

.btn-toggle.active {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.search-input {
  flex: 1 1 260px;
  font: inherit;
  padding: 0.5rem 0.9rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
}

.search-input:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.sort-controls {
  display: flex;
  gap: 0.4rem;
  align-items: center;
  flex-wrap: wrap;
}

.sort-label {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-right: 0.2rem;
}

.last-updated {
  color: var(--text-muted);
  font-size: 0.8rem;
  margin-left: 0.3rem;
}

.btn[disabled] {
  opacity: 0.6;
  cursor: default;
}

.content {
  flex: 1;
  padding: 1.5rem;
  max-width: 1100px;
  width: 100%;
  margin: 0 auto;
}

.status-message {
  color: var(--text-muted);
  text-align: center;
  margin-top: 3rem;
  font-size: 1.05rem;
}

.channel-group {
  margin-bottom: 2rem;
}

.channel-name {
  display: inline-block;
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
  margin-bottom: 0.6rem;
}

.channel-name:hover {
  color: var(--accent);
  text-decoration: underline;
}

.video-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}

.video-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.video-thumb-link {
  display: block;
  aspect-ratio: 16 / 9;
  background: #000;
}

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

.video-info {
  padding: 0.7rem 0.9rem 0.9rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.video-title {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
  text-decoration: none;
  line-height: 1.3;
}

.video-title:hover {
  color: var(--accent);
  text-decoration: underline;
}

.video-time {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.video-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.site-footer {
  text-align: center;
  padding: 1.2rem;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.9rem;
}

.site-footer a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}

.site-footer a:hover {
  text-decoration: underline;
}