/* ============================================
   China Trending Viewer - Cyberpunk Style
   ============================================ */

:root {
  /* Color Palette - Cyberpunk Dark */
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-tertiary: #1a1a25;
  --bg-card: #15151f;

  --accent-cyan: #00f0ff;
  --accent-pink: #ff00aa;
  --accent-yellow: #ffd700;
  --accent-silver: #c0c0c0;
  --accent-bronze: #cd7f32;

  --text-primary: #ffffff;
  --text-secondary: #8888aa;
  --text-muted: #555566;

  --border-glow: rgba(0, 240, 255, 0.3);
  --border-subtle: rgba(255, 255, 255, 0.08);

  /* Background Pattern */
  --bg-gradient-1: radial-gradient(ellipse at 20% 20%, rgba(0, 240, 255, 0.08) 0%, transparent 50%);
  --bg-gradient-2: radial-gradient(ellipse at 80% 80%, rgba(255, 0, 170, 0.06) 0%, transparent 50%);

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;

  /* Typography */
  --font-display: 'Orbitron', sans-serif;
  --font-body: 'Noto Sans SC', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s ease;
}

/* Light Theme */
[data-theme="light"] {
  --bg-primary: #f5f7fa;
  --bg-secondary: #ffffff;
  --bg-tertiary: #e8ecf1;
  --bg-card: #ffffff;

  --accent-cyan: #0099ff;
  --accent-pink: #e91e63;

  --text-primary: #1a1a2e;
  --text-secondary: #5a5a7a;
  --text-muted: #8a8aaa;

  --border-glow: rgba(0, 153, 255, 0.3);
  --border-subtle: rgba(0, 0, 0, 0.08);

  --bg-gradient-1: radial-gradient(ellipse at 20% 20%, rgba(0, 153, 255, 0.08) 0%, transparent 50%);
  --bg-gradient-2: radial-gradient(ellipse at 80% 80%, rgba(233, 30, 99, 0.06) 0%, transparent 50%);
}

/* Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Background Pattern */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    var(--bg-gradient-1),
    var(--bg-gradient-2),
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 50px,
      rgba(0, 240, 255, 0.02) 50px,
      rgba(0, 240, 255, 0.02) 51px
    ),
    repeating-linear-gradient(
      90deg,
      transparent,
      transparent 50px,
      rgba(0, 240, 255, 0.02) 50px,
      rgba(0, 240, 255, 0.02) 51px
    );
  pointer-events: none;
  z-index: -1;
}

/* App Container */
.app {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-md);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ============================================
   Header
   ============================================ */

.header {
  padding: var(--space-lg) 0;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.logo-icon {
  width: 48px;
  height: 48px;
  animation: pulse-glow 3s ease-in-out infinite;
}

@keyframes pulse-glow {
  0%, 100% { filter: drop-shadow(0 0 4px var(--accent-cyan)); }
  50% { filter: drop-shadow(0 0 12px var(--accent-cyan)); }
}

.title {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-pink));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: 0 0 30px rgba(0, 240, 255, 0.5);
}

.refresh-btn {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  border: 1px solid var(--border-glow);
  background: var(--bg-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-normal);
}

.refresh-btn:hover {
  background: var(--bg-tertiary);
  border-color: var(--accent-cyan);
  box-shadow: 0 0 20px rgba(0, 240, 255, 0.3);
}

.refresh-icon {
  width: 24px;
  height: 24px;
  fill: var(--accent-cyan);
}

.refresh-btn.loading .refresh-icon {
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* Theme Toggle Button */
.header-actions {
  display: flex;
  gap: var(--space-sm);
}

.theme-btn {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  border: 1px solid var(--border-glow);
  background: var(--bg-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-normal);
}

.theme-btn:hover {
  background: var(--bg-tertiary);
  border-color: var(--accent-cyan);
  box-shadow: 0 0 20px rgba(0, 240, 255, 0.3);
}

.theme-icon {
  width: 24px;
  height: 24px;
  fill: var(--accent-cyan);
}

.theme-btn .sun-icon { display: none; }
.theme-btn .moon-icon { display: block; }

[data-theme="light"] .theme-btn .sun-icon { display: block; }
[data-theme="light"] .theme-btn .moon-icon { display: none; }

/* ============================================
   Platform Tabs
   ============================================ */

.platform-tabs {
  display: flex;
  gap: var(--space-sm);
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--border-subtle);
  overflow-x: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--accent-cyan) var(--bg-secondary);
}

.platform-tabs::-webkit-scrollbar {
  height: 4px;
}

.platform-tabs::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

.platform-tabs::-webkit-scrollbar-thumb {
  background: var(--accent-cyan);
  border-radius: 2px;
}

.tab {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  border-radius: 8px;
  transition: var(--transition-normal);
  white-space: nowrap;
  position: relative;
}

.tab::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--accent-cyan);
  transition: var(--transition-normal);
}

.tab:hover {
  color: var(--text-primary);
  background: var(--bg-tertiary);
}

.tab.active {
  color: var(--accent-cyan);
  background: rgba(0, 240, 255, 0.1);
}

.tab.active::after {
  width: 80%;
}

.platform-icon {
  width: 20px;
  height: 20px;
}

/* ============================================
   Main Content
   ============================================ */

.main {
  flex: 1;
  padding: var(--space-lg) 0;
}

.trending-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

@media (max-width: 1023px) {
  .trending-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 767px) {
  .trending-list {
    grid-template-columns: 1fr;
  }

  .title {
    font-size: 1.5rem;
  }

  .app {
    padding: var(--space-sm);
  }

  .header-content {
    flex-wrap: wrap;
  }

  .logo {
    flex: 1;
  }

  .header-actions {
    display: flex;
    gap: var(--space-xs);
  }

  .refresh-btn,
  .theme-btn {
    width: 40px;
    height: 40px;
  }

  .platform-tabs {
    padding: var(--space-sm) 0;
    gap: var(--space-xs);
  }

  .tab {
    padding: var(--space-xs) var(--space-sm);
    font-size: 0.85rem;
  }

  .platform-icon {
    width: 16px;
    height: 16px;
  }

  .trending-card {
    padding: var(--space-sm);
  }

  .card-title {
    font-size: 0.9rem;
  }

  .card-meta {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-xs);
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .footer-content > * {
    width: 100%;
  }
}

/* ============================================
   Trending Card
   ============================================ */

.trending-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: var(--space-md);
  position: relative;
  overflow: hidden;
  transition: var(--transition-normal);
}

.trending-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--accent-cyan);
  opacity: 0.5;
  transition: var(--transition-normal);
}

.trending-card:hover {
  transform: translateY(-2px);
  border-color: var(--border-glow);
  box-shadow:
    0 4px 20px rgba(0, 0, 0, 0.3),
    0 0 20px rgba(0, 240, 255, 0.1);
}

.trending-card:hover::before {
  opacity: 1;
  box-shadow: 0 0 10px var(--accent-cyan);
}

/* Rank Badge */
.rank-badge {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  width: 28px;
  height: 28px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
}

.rank-badge.rank-1 {
  background: linear-gradient(135deg, var(--accent-yellow), #ffaa00);
  color: #000;
  box-shadow: 0 0 10px rgba(255, 215, 0, 0.5);
}

.rank-badge.rank-2 {
  background: linear-gradient(135deg, var(--accent-silver), #a0a0a0);
  color: #000;
  box-shadow: 0 0 10px rgba(192, 192, 192, 0.5);
}

.rank-badge.rank-3 {
  background: linear-gradient(135deg, var(--accent-bronze), #a05a20);
  color: #fff;
  box-shadow: 0 0 10px rgba(205, 127, 50, 0.5);
}

.rank-badge.rank-other {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
}

/* Card Content */
.card-content {
  padding-right: 30px;
}

.card-title {
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.5;
  margin-bottom: var(--space-sm);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-title a {
  color: var(--text-primary);
  text-decoration: none;
  transition: var(--transition-fast);
}

.card-title a:hover {
  color: var(--accent-cyan);
}

.card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

.card-hot {
  font-family: var(--font-mono);
  color: var(--accent-pink);
  font-weight: 600;
}

.card-hot::before {
  content: '🔥';
  margin-right: 4px;
}

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

/* Loading State */
.loading {
  grid-column: 1 / -1;
  text-align: center;
  padding: var(--space-xl);
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border-subtle);
  border-top-color: var(--accent-cyan);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto var(--space-md);
}

.loading-text {
  color: var(--text-secondary);
}

/* Empty State */
.empty-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: var(--space-xl);
  color: var(--text-secondary);
}

/* Error State */
.error-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: var(--space-xl);
  color: var(--text-secondary);
}

.error-icon {
  width: 48px;
  height: 48px;
  fill: var(--accent-pink);
  margin-bottom: var(--space-md);
}

.error-message {
  color: var(--accent-pink);
  margin-bottom: var(--space-sm);
}

.retry-btn {
  margin-top: var(--space-md);
  padding: var(--space-sm) var(--space-lg);
  background: var(--accent-cyan);
  color: #000;
  border: none;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
}

.retry-btn:hover {
  opacity: 0.9;
  transform: scale(1.02);
}

/* ============================================
   Footer
   ============================================ */

.footer {
  padding: var(--space-lg) 0;
  border-top: 1px solid var(--border-subtle);
  margin-top: auto;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
  font-size: 0.85rem;
  color: var(--text-muted);
}

.data-source {
  flex: 1;
  min-width: 200px;
}

.last-update {
  color: var(--text-secondary);
}

.github-link {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  color: var(--text-secondary);
  text-decoration: none;
  transition: var(--transition-fast);
}

.github-link:hover {
  color: var(--accent-cyan);
}

.github-icon {
  width: 20px;
  height: 20px;
}

/* ============================================
   Animations
   ============================================ */

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.trending-card {
  animation: fade-in 0.3s ease forwards;
}

.trending-card:nth-child(1) { animation-delay: 0.05s; }
.trending-card:nth-child(2) { animation-delay: 0.1s; }
.trending-card:nth-child(3) { animation-delay: 0.15s; }
.trending-card:nth-child(4) { animation-delay: 0.2s; }
.trending-card:nth-child(5) { animation-delay: 0.25s; }
.trending-card:nth-child(6) { animation-delay: 0.3s; }
.trending-card:nth-child(7) { animation-delay: 0.35s; }
.trending-card:nth-child(8) { animation-delay: 0.4s; }
.trending-card:nth-child(9) { animation-delay: 0.45s; }
.trending-card:nth-child(10) { animation-delay: 0.5s; }