/* ===================================
   LLM Hub - Design System v2
   Inspired by GitHub Primer + OpenRouter
   =================================== */

/* === CSS Variables - GitHub Primer Inspired === */
:root {
  /* GitHub Dark Default Colors */
  --color-canvas-default: #0d1117;
  --color-canvas-subtle: #161b22;
  --color-canvas-inset: #010409;
  --color-canvas-overlay: #1c2128;

  /* Foreground */
  --color-fg-default: #e6edf3;
  --color-fg-muted: #8b949e;
  --color-fg-subtle: #6e7681;

  /* Border */
  --color-border-default: #30363d;
  --color-border-muted: #21262d;
  --color-border-subtle: rgba(240, 246, 252, 0.1);

  /* Accent - OpenRouter Teal/Cyan Fusion */
  --color-accent-fg: #58a6ff;
  --color-accent-emphasis: #1f6feb;
  --color-accent-muted: rgba(56, 139, 253, 0.4);
  --color-accent-subtle: rgba(56, 139, 253, 0.15);

  /* OpenRouter Cyan Accent */
  --color-cyan-fg: #39d0d8;
  --color-cyan-emphasis: #22a6b3;
  --color-cyan-subtle: rgba(57, 208, 216, 0.15);

  /* Success/Done */
  --color-success-fg: #3fb950;
  --color-success-emphasis: #238636;
  --color-success-subtle: rgba(46, 160, 67, 0.15);

  /* Warning */
  --color-attention-fg: #d29922;
  --color-attention-emphasis: #9e6a03;
  --color-attention-subtle: rgba(187, 128, 9, 0.15);

  /* Danger */
  --color-danger-fg: #f85149;
  --color-danger-emphasis: #da3633;
  --color-danger-subtle: rgba(248, 81, 73, 0.15);

  /* Gradients */
  --gradient-hero: linear-gradient(180deg, rgba(56, 139, 253, 0.15) 0%, transparent 30%);
  --gradient-accent: linear-gradient(135deg, #58a6ff 0%, #39d0d8 100%);
  --gradient-cyan: linear-gradient(135deg, #22a6b3 0%, #39d0d8 100%);

  /* Typography - GitHub Style */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", Helvetica, Arial, sans-serif;
  --font-family-mono: ui-monospace, SFMono-Regular, SF Mono, Menlo, Consolas, Liberation Mono, monospace;

  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-lg: 20px;
  --font-size-xl: 24px;
  --font-size-2xl: 32px;
  --font-size-3xl: 40px;
  --font-size-4xl: 48px;

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing - 4px grid */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 16px;
  --space-4: 24px;
  --space-5: 32px;
  --space-6: 40px;
  --space-7: 48px;
  --space-8: 64px;
  --space-9: 80px;
  --space-10: 96px;

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 0 rgba(27, 31, 36, 0.04);
  --shadow-md: 0 3px 6px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.25);
  --shadow-xl: 0 12px 48px rgba(0, 0, 0, 0.3);

  /* Transitions */
  --duration-fast: 80ms;
  --duration-normal: 150ms;
  --duration-slow: 250ms;
  --easing-default: cubic-bezier(0.3, 0, 0.5, 1);
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-normal);
  color: var(--color-fg-default);
  background-color: var(--color-canvas-default);
  min-height: 100vh;
}

a {
  color: var(--color-accent-fg);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* === Container === */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.container-lg {
  max-width: 1400px;
}

/* === Header - GitHub Style === */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-canvas-default);
  border-bottom: 1px solid var(--color-border-default);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: var(--space-4);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-fg-default);
  text-decoration: none;
}

.logo:hover {
  text-decoration: none;
  color: var(--color-fg-default);
}

.logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--gradient-cyan);
  border-radius: var(--radius-sm);
  font-size: 18px;
}

.nav {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.nav-link {
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-fg-default);
  border-radius: var(--radius-sm);
  transition: background-color var(--duration-fast) var(--easing-default);
}

.nav-link:hover {
  background-color: var(--color-canvas-subtle);
  text-decoration: none;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: transparent;
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-sm);
  color: var(--color-fg-muted);
  cursor: pointer;
  transition: all var(--duration-fast) var(--easing-default);
}

.theme-toggle:hover {
  background-color: var(--color-canvas-subtle);
  border-color: var(--color-border-default);
  color: var(--color-fg-default);
}

/* === Hero Section === */
.hero {
  position: relative;
  padding: var(--space-10) 0 var(--space-8);
  text-align: center;
  background: var(--gradient-hero);
  border-bottom: 1px solid var(--color-border-muted);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  margin-bottom: var(--space-4);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  color: var(--color-cyan-fg);
  background-color: var(--color-cyan-subtle);
  border: 1px solid rgba(57, 208, 216, 0.3);
  border-radius: var(--radius-full);
}

.hero-title {
  max-width: 900px;
  margin: 0 auto var(--space-4);
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  letter-spacing: -0.02em;
}

.gradient-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  max-width: 640px;
  margin: 0 auto var(--space-5);
  font-size: var(--font-size-lg);
  color: var(--color-fg-muted);
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: var(--space-7);
  margin-bottom: var(--space-5);
}

.stat {
  text-align: center;
}

.stat-value {
  display: block;
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-fg-default);
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-fg-muted);
}

.hero-cta {
  display: flex;
  justify-content: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}

/* === Buttons - GitHub Style === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 5px 16px;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  line-height: 20px;
  white-space: nowrap;
  vertical-align: middle;
  cursor: pointer;
  user-select: none;
  border: 1px solid;
  border-radius: var(--radius-sm);
  transition: all var(--duration-fast) var(--easing-default);
  text-decoration: none;
}

.btn:hover {
  text-decoration: none;
}

.btn-primary {
  color: #ffffff;
  background-color: var(--color-success-emphasis);
  border-color: rgba(240, 246, 252, 0.1);
}

.btn-primary:hover {
  background-color: #2ea043;
}

.btn-secondary {
  color: var(--color-fg-default);
  background-color: var(--color-canvas-subtle);
  border-color: var(--color-border-default);
}

.btn-secondary:hover {
  background-color: var(--color-canvas-overlay);
  border-color: var(--color-border-default);
}

.btn-accent {
  color: #ffffff;
  background: var(--gradient-cyan);
  border-color: transparent;
}

.btn-accent:hover {
  opacity: 0.9;
}

.btn-sm {
  padding: 3px 12px;
  font-size: var(--font-size-xs);
}

.btn-lg {
  padding: 10px 24px;
  font-size: var(--font-size-base);
}

/* === Sections === */
.section {
  padding: var(--space-8) 0;
}

.section-alt {
  background-color: var(--color-canvas-subtle);
}

.section-header {
  margin-bottom: var(--space-5);
  text-align: center;
}

.section-badge {
  display: inline-block;
  padding: var(--space-1) var(--space-2);
  margin-bottom: var(--space-2);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-accent-fg);
  background-color: var(--color-accent-subtle);
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.section-title {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--space-2);
}

.section-subtitle {
  font-size: var(--font-size-base);
  color: var(--color-fg-muted);
}

/* === Ranking Cards - GitHub Card Style === */
.ranking-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-3);
}

.ranking-card {
  position: relative;
  padding: var(--space-4);
  background-color: var(--color-canvas-subtle);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-md);
  transition: border-color var(--duration-fast) var(--easing-default);
}

.ranking-card:hover {
  border-color: var(--color-border-default);
  background-color: var(--color-canvas-overlay);
}

.ranking-card.rank-1 {
  border-color: var(--color-attention-fg);
  background: linear-gradient(135deg, rgba(210, 153, 34, 0.1) 0%, transparent 50%);
}

.ranking-card.rank-2 {
  border-color: var(--color-fg-muted);
}

.ranking-card.rank-3 {
  border-color: #cd7f32;
}

.rank-badge {
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  padding: 2px 8px;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-canvas-default);
  background: var(--gradient-cyan);
  border-radius: var(--radius-full);
}

.ranking-provider {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-1);
}

.ranking-model {
  font-size: var(--font-size-sm);
  font-family: var(--font-family-mono);
  color: var(--color-cyan-fg);
  margin-bottom: var(--space-3);
}

.ranking-reason {
  font-size: var(--font-size-sm);
  color: var(--color-fg-muted);
  line-height: var(--line-height-relaxed);
}

.ranking-action {
  margin-top: var(--space-4);
}

/* === Filters - GitHub Form Style === */
.filters {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: var(--space-3);
  padding: var(--space-4);
  margin-bottom: var(--space-4);
  background-color: var(--color-canvas-subtle);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-md);
}

.filter-group {
  flex: 1;
  min-width: 160px;
}

.filter-label {
  display: block;
  margin-bottom: var(--space-1);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  color: var(--color-fg-muted);
}

.filter-select {
  width: 100%;
  padding: 5px 12px;
  font-size: var(--font-size-sm);
  line-height: 20px;
  color: var(--color-fg-default);
  background-color: var(--color-canvas-default);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-sm);
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%238b949e'%3E%3Cpath d='M4.427 7.427l3.396 3.396a.25.25 0 00.354 0l3.396-3.396A.25.25 0 0011.396 7H4.604a.25.25 0 00-.177.427z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  padding-right: 32px;
  cursor: pointer;
}

.filter-select:focus {
  outline: none;
  border-color: var(--color-accent-fg);
  box-shadow: 0 0 0 3px var(--color-accent-muted);
}

.results-info {
  margin-bottom: var(--space-3);
  font-size: var(--font-size-sm);
  color: var(--color-fg-muted);
}

/* === Data Table - GitHub Table Style === */
.table-container {
  overflow-x: auto;
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-md);
  background-color: var(--color-canvas-subtle);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--font-size-sm);
}

.data-table th {
  padding: var(--space-3);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-fg-muted);
  text-align: left;
  background-color: var(--color-canvas-subtle);
  border-bottom: 1px solid var(--color-border-default);
  white-space: nowrap;
}

.data-table td {
  padding: var(--space-3);
  border-bottom: 1px solid var(--color-border-muted);
  vertical-align: middle;
}

.data-table tbody tr:hover {
  background-color: var(--color-canvas-overlay);
}

.data-table tbody tr:last-child td {
  border-bottom: none;
}

.price-unit {
  font-weight: var(--font-weight-normal);
  color: var(--color-fg-subtle);
}

.provider-name {
  font-weight: var(--font-weight-semibold);
}

.model-name {
  font-family: var(--font-family-mono);
  color: var(--color-cyan-fg);
}

.context-size {
  font-family: var(--font-family-mono);
  color: var(--color-fg-muted);
}

.price {
  font-family: var(--font-family-mono);
  font-weight: var(--font-weight-medium);
}

.price.free {
  color: var(--color-success-fg);
  font-weight: var(--font-weight-semibold);
}

/* === Badges === */
.free-tier-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-full);
  white-space: nowrap;
}

.free-tier-badge.available {
  color: var(--color-success-fg);
  background-color: var(--color-success-subtle);
}

.free-tier-badge.credits {
  color: var(--color-attention-fg);
  background-color: var(--color-attention-subtle);
}

.free-tier-badge.unavailable {
  color: var(--color-fg-muted);
  background-color: var(--color-canvas-overlay);
}

.capability-tag {
  display: inline-block;
  padding: 0 6px;
  margin: 1px;
  font-size: 10px;
  font-weight: var(--font-weight-medium);
  color: var(--color-fg-muted);
  background-color: var(--color-canvas-overlay);
  border-radius: var(--radius-full);
}

.speed-indicator {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: var(--font-size-xs);
}

.speed-indicator.ultra-fast {
  color: var(--color-success-fg);
}

.speed-indicator.fast {
  color: var(--color-cyan-fg);
}

.speed-indicator.medium {
  color: var(--color-attention-fg);
}

/* === Providers Grid === */
.providers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-3);
}

.provider-card {
  padding: var(--space-4);
  background-color: var(--color-canvas-subtle);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-md);
  transition: all var(--duration-fast) var(--easing-default);
}

.provider-card:hover {
  border-color: var(--color-accent-fg);
}

.provider-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-2);
}

.provider-name-large {
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
}

.provider-free-badge {
  padding: 2px 8px;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  color: var(--color-success-fg);
  background-color: var(--color-success-subtle);
  border-radius: var(--radius-full);
}

.provider-description {
  font-size: var(--font-size-sm);
  color: var(--color-fg-muted);
  margin-bottom: var(--space-2);
  line-height: var(--line-height-relaxed);
}

.provider-models-count {
  font-size: var(--font-size-xs);
  color: var(--color-fg-subtle);
  margin-bottom: var(--space-4);
}

.provider-actions {
  display: flex;
  gap: var(--space-2);
}

/* === CTA Section === */
.section-cta {
  text-align: center;
  background: linear-gradient(180deg, var(--color-canvas-subtle) 0%, var(--color-canvas-default) 100%);
  border-top: 1px solid var(--color-border-muted);
}

.cta-content {
  max-width: 560px;
  margin: 0 auto;
}

.cta-title {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--space-2);
}

.cta-text {
  color: var(--color-fg-muted);
  margin-bottom: var(--space-4);
}

.cta-form {
  display: flex;
  gap: var(--space-2);
  max-width: 400px;
  margin: 0 auto;
}

.cta-input {
  flex: 1;
  padding: 5px 12px;
  font-size: var(--font-size-sm);
  color: var(--color-fg-default);
  background-color: var(--color-canvas-default);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-sm);
}

.cta-input:focus {
  outline: none;
  border-color: var(--color-accent-fg);
  box-shadow: 0 0 0 3px var(--color-accent-muted);
}

.cta-input::placeholder {
  color: var(--color-fg-subtle);
}

/* === Footer === */
.footer {
  padding: var(--space-6) 0;
  border-top: 1px solid var(--color-border-muted);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--space-2);
}

.footer-text {
  font-size: var(--font-size-xs);
  color: var(--color-fg-muted);
}

.footer-disclaimer {
  font-size: var(--font-size-xs);
  color: var(--color-fg-subtle);
}

/* === Responsive === */
@media (max-width: 768px) {
  .hero {
    padding: var(--space-8) 0 var(--space-6);
  }

  .hero-title {
    font-size: var(--font-size-2xl);
  }

  .hero-stats {
    gap: var(--space-5);
  }

  .stat-value {
    font-size: var(--font-size-xl);
  }

  .nav {
    display: none;
  }

  .filters {
    flex-direction: column;
  }

  .filter-group {
    width: 100%;
  }

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

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

  .cta-form {
    flex-direction: column;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }
}

/* === Animations === */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(8px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.ranking-card,
.provider-card {
  animation: fadeInUp 0.3s ease-out forwards;
  opacity: 0;
}

.ranking-card:nth-child(1) {
  animation-delay: 0.05s;
}

.ranking-card:nth-child(2) {
  animation-delay: 0.1s;
}

.ranking-card:nth-child(3) {
  animation-delay: 0.15s;
}

.ranking-card:nth-child(4) {
  animation-delay: 0.2s;
}

.ranking-card:nth-child(5) {
  animation-delay: 0.25s;
}

.ranking-card:nth-child(6) {
  animation-delay: 0.3s;
}

.provider-card:nth-child(1) {
  animation-delay: 0.05s;
}

.provider-card:nth-child(2) {
  animation-delay: 0.08s;
}

.provider-card:nth-child(3) {
  animation-delay: 0.11s;
}

.provider-card:nth-child(4) {
  animation-delay: 0.14s;
}

.provider-card:nth-child(5) {
  animation-delay: 0.17s;
}

.provider-card:nth-child(6) {
  animation-delay: 0.2s;
}