:root {
  color-scheme: dark;
  --bg: #0f172a;
  --panel: #111827;
  --panel-soft: #1f2937;
  --panel-hover: #243244;
  --border: #334155;
  --text: #e5e7eb;
  --text-soft: #94a3b8;
  --primary: #2d6cdf;
  --success: #16a34a;
  --shadow: 0 16px 40px rgba(15, 23, 42, 0.35);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

button,
input,
video,
iframe {
  font: inherit;
}

.hidden {
  display: none !important;
}

.app-shell {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  padding: 20px 16px;
  border-right: 1px solid var(--border);
  background: rgba(15, 23, 42, 0.92);
  position: sticky;
  top: 0;
  height: 100vh;
}

.brand h1 {
  margin: 0;
  font-size: 26px;
}

.brand p {
  margin: 8px 0 0;
  color: var(--text-soft);
  font-size: 14px;
}

.menu-list {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

.menu-button {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--panel);
  color: var(--text);
  text-align: left;
  cursor: pointer;
  transition: 0.2s ease;
}

.menu-button:hover {
  background: var(--panel-hover);
}

.menu-button.active {
  border-color: rgba(45, 108, 223, 0.6);
  background: rgba(45, 108, 223, 0.16);
  box-shadow: inset 0 0 0 1px rgba(45, 108, 223, 0.22);
}

.content {
  display: grid;
  gap: 20px;
  padding: 20px;
}

.player-panel,
.channel-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 20px;
  box-shadow: var(--shadow);
}

.player-panel {
  padding: 20px;
}

.player-toolbar,
.channel-toolbar {
  display: flex;
  gap: 16px;
  justify-content: space-between;
  align-items: center;
}

.player-toolbar h2,
.channel-heading h2 {
  margin: 0;
  font-size: 24px;
}

.player-toolbar p,
.channel-heading p {
  margin: 8px 0 0;
  color: var(--text-soft);
  font-size: 14px;
}

.badge {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.16);
  color: var(--text-soft);
  white-space: nowrap;
}

.badge.playing {
  background: rgba(22, 163, 74, 0.18);
  color: #86efac;
}

.badge.web {
  background: rgba(45, 108, 223, 0.18);
  color: #93c5fd;
}

.player-stage {
  position: relative;
  margin-top: 18px;
  overflow: hidden;
  border-radius: 18px;
  border: 1px solid var(--border);
  background: #020617;
  min-height: 420px;
}

.video-player,
.frame-player {
  width: 100%;
  height: min(68vh, 720px);
  border: 0;
  background: #000;
}

.empty-state {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 24px;
  color: var(--text-soft);
  text-align: center;
}

.channel-panel {
  padding: 20px;
}

.search-box {
  display: grid;
  gap: 8px;
  color: var(--text-soft);
  font-size: 14px;
}

.search-box input {
  width: min(320px, 70vw);
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--panel-soft);
  color: var(--text);
  outline: none;
}

.search-box input:focus {
  border-color: var(--primary);
}

.channel-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.channel-card {
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: var(--panel-soft);
  color: var(--text);
  text-align: left;
  cursor: pointer;
  transition: 0.2s ease;
}

.channel-card:hover {
  transform: translateY(-1px);
  background: var(--panel-hover);
}

.channel-card.active {
  border-color: rgba(45, 108, 223, 0.7);
  background: rgba(45, 108, 223, 0.18);
}

.channel-card .channel-name {
  display: block;
  font-weight: 600;
  line-height: 1.45;
}

.channel-card .channel-meta {
  display: block;
  margin-top: 8px;
  color: var(--text-soft);
  font-size: 13px;
}

.status-tip {
  display: grid;
  place-items: center;
  min-height: 180px;
  border: 1px dashed var(--border);
  border-radius: 16px;
  color: var(--text-soft);
}

@media (max-width: 960px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--border);
  }

  .menu-list {
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  }

  .player-toolbar,
  .channel-toolbar {
    flex-direction: column;
    align-items: flex-start;
  }

  .search-box input {
    width: min(100%, 420px);
  }

  .video-player,
  .frame-player {
    height: 56vw;
    min-height: 260px;
    max-height: 70vh;
  }
}