/* ==========================================================================
   Design System & Custom Properties
   ========================================================================== */
:root {
  --font-family: 'Plus Jakarta Sans', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  
  /* Color Palette - Dark default */
  --bg-primary: #0a0d14;
  --bg-secondary: #101623;
  --bg-card: rgba(21, 29, 45, 0.7);
  --bg-card-hover: rgba(30, 42, 65, 0.85);
  
  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(99, 102, 241, 0.4);
  
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --accent-primary: #6366f1;
  --accent-primary-hover: #4f46e5;
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
  
  --tag-learning: #38bdf8;
  --tag-tools: #a855f7;
  --tag-productivity: #34d399;
  --tag-design: #f472b6;
  --tag-reference: #fbbf24;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 12px 30px rgba(0, 0, 0, 0.45);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.85);
  --bg-card-hover: rgba(255, 255, 255, 1);
  
  --border-color: rgba(0, 0, 0, 0.08);
  --border-hover: rgba(99, 102, 241, 0.5);
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-dim: #94a3b8;
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 14px 30px rgba(0, 0, 0, 0.08);
}

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

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color 0.3s ease, color 0.3s ease;
  background-image: radial-gradient(circle at 50% 0%, rgba(99, 102, 241, 0.08) 0%, transparent 60%);
  background-repeat: no-repeat;
}

.container {
  width: 100%;
  max-width: 1180px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: backdrop-filter;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background-color: rgba(10, 13, 20, 0.75);
  border-bottom: 1px solid var(--border-color);
  transition: background-color 0.3s ease;
}

[data-theme="light"] .site-header {
  background-color: rgba(248, 250, 252, 0.85);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.25rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--accent-gradient);
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 1.1rem;
}

.logo-text strong {
  color: var(--accent-primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: inherit;
  font-size: 0.925rem;
  font-weight: 600;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-full);
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
}

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

.btn-primary:hover {
  background: var(--accent-primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
}

.btn-outline {
  background: transparent;
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

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

.btn-icon {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.1rem;
  transition: var(--transition);
}

.btn-icon:hover {
  border-color: var(--accent-primary);
  transform: rotate(15deg);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  padding: 4.5rem 0 3rem;
  text-align: center;
}

.hero-content {
  max-width: 820px;
}

.hero-badge {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-primary);
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.25);
  padding: 0.35rem 1rem;
  border-radius: var(--radius-full);
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.25rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
  background: linear-gradient(180deg, var(--text-main) 60%, var(--text-muted) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 660px;
  margin: 0 auto 2.5rem;
}

/* ==========================================================================
   Search & Filters
   ========================================================================== */
.search-box-wrapper {
  max-width: 620px;
  margin: 0 auto 2rem;
}

.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  padding: 0.5rem 1.25rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.search-box:focus-within {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.2);
}

.search-icon {
  font-size: 1.1rem;
  margin-right: 0.75rem;
  opacity: 0.7;
}

.search-box input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  font-family: inherit;
  font-size: 1rem;
  color: var(--text-main);
}

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

.search-counter {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-weight: 500;
}

.filter-pills {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.6rem;
}

.pill {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 0.5rem 1.1rem;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: var(--transition);
}

.pill:hover {
  color: var(--text-main);
  border-color: var(--text-dim);
}

.pill.active {
  background: var(--accent-primary);
  color: #ffffff;
  border-color: var(--accent-primary);
  box-shadow: 0 2px 10px rgba(99, 102, 241, 0.35);
}

/* ==========================================================================
   Main Content & Cards Grid
   ========================================================================== */
.main-content {
  padding-bottom: 4rem;
  flex: 1;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.section-title {
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.results-badge {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.resource-card {
  background: var(--bg-card);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.6rem;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  position: relative;
}

.resource-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  box-shadow: var(--shadow-lg);
}

.card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.card-tag {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
}

.tag-learning {
  background: rgba(56, 189, 248, 0.12);
  color: var(--tag-learning);
}

.tag-tools {
  background: rgba(168, 85, 247, 0.12);
  color: var(--tag-tools);
}

.tag-productivity {
  background: rgba(52, 211, 153, 0.12);
  color: var(--tag-productivity);
}

.tag-design {
  background: rgba(244, 114, 182, 0.12);
  color: var(--tag-design);
}

.tag-reference {
  background: rgba(251, 191, 36, 0.12);
  color: var(--tag-reference);
}

.copy-btn {
  background: transparent;
  border: none;
  font-size: 0.95rem;
  cursor: pointer;
  opacity: 0.45;
  transition: var(--transition);
  padding: 0.2rem;
  border-radius: 4px;
}

.copy-btn:hover {
  opacity: 1;
  transform: scale(1.15);
}

.card-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
  letter-spacing: -0.01em;
}

.card-desc {
  font-size: 0.925rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 1.5rem;
  flex: 1;
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

.card-domain {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-family: monospace;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent-primary);
  text-decoration: none;
  transition: var(--transition);
}

.card-link span {
  transition: transform 0.2s ease;
}

.card-link:hover {
  color: #fff;
}

[data-theme="light"] .card-link:hover {
  color: var(--accent-primary-hover);
}

.card-link:hover span {
  transform: translate(2px, -2px);
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 4rem 1rem;
}

.empty-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  opacity: 0.6;
}

.empty-state h3 {
  font-size: 1.35rem;
  margin-bottom: 0.5rem;
}

.empty-state p {
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

/* ==========================================================================
   Suggest Section Banner
   ========================================================================= */
.suggest-section {
  padding-bottom: 4rem;
}

.suggest-card {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15) 0%, rgba(168, 85, 247, 0.08) 100%);
  border: 1px solid rgba(99, 102, 241, 0.25);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.suggest-text h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
}

.suggest-text p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
  padding: 2.5rem 0;
  font-size: 0.9rem;
  color: var(--text-dim);
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

/* ==========================================================================
   Toast Notification
   ========================================================================== */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: #1e293b;
  color: #fff;
  padding: 0.8rem 1.4rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  pointer-events: none;
  transform: translateY(15px);
  transition: opacity 0.3s ease, transform 0.3s ease;
  z-index: 1000;
}

.toast.show {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

/* ==========================================================================
   Responsive Adjustments
   ========================================================================== */
@media (max-width: 640px) {
  .hero-section {
    padding: 3rem 0 2rem;
  }
  
  .cards-grid {
    grid-template-columns: 1fr;
  }
  
  .suggest-card {
    flex-direction: column;
    text-align: center;
    align-items: center;
  }
  
  .footer-content {
    flex-direction: column;
    text-align: center;
  }
}