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

:root {
  --color-bg: #0f1117;
  --color-surface: #1a1d27;
  --color-surface-hover: #232736;
  --color-border: #2a2e3d;
  --color-primary: #6c63ff;
  --color-primary-hover: #5a52e0;
  --color-text: #e4e4e7;
  --color-text-muted: #9ca3af;
  --color-accent-green: #34d399;
  --color-accent-blue: #60a5fa;
  --color-accent-orange: #fb923c;
  --radius: 10px;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
}

body {
  font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--color-primary-hover);
}

/* Layout */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 16px 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.site-logo {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.5px;
}

.site-logo span {
  color: var(--color-primary);
}

.site-nav {
  display: flex;
  gap: 24px;
}

.site-nav a {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--color-text);
}

/* Hero */
.hero {
  text-align: center;
  padding: 80px 0 60px;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 800;
  letter-spacing: -1px;
  margin-bottom: 16px;
}

.hero h1 span {
  color: var(--color-primary);
}

.hero p {
  color: var(--color-text-muted);
  font-size: 1.15rem;
  max-width: 560px;
  margin: 0 auto;
}

.hero-search-hint {
  margin-top: 20px !important;
  font-size: 0.88rem !important;
  opacity: 0.5;
  cursor: pointer;
}

.hero-search-hint kbd {
  display: inline-block;
  padding: 2px 8px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 0.8rem;
  font-family: inherit;
  color: var(--color-text-muted);
}

/* Category Cards */
.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
  padding-bottom: 80px;
}

.category-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.category-card:hover {
  transform: translateY(-3px);
  border-color: var(--color-primary);
  box-shadow: var(--shadow);
}

.category-card .card-icon {
  font-size: 2rem;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: rgba(108, 99, 255, 0.1);
}

.category-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
}

.category-card p {
  color: var(--color-text-muted);
  font-size: 0.92rem;
  flex-grow: 1;
}

.category-card .card-link {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.category-card .card-link::after {
  content: '\2192';
  transition: transform 0.2s;
}

.category-card:hover .card-link::after {
  transform: translateX(4px);
}

/* Category Page */
.category-header {
  padding: 60px 0 40px;
}

.category-header h1 {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.category-header p {
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

.breadcrumb {
  display: flex;
  gap: 8px;
  align-items: center;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.breadcrumb a {
  color: var(--color-text-muted);
}

.breadcrumb a:hover {
  color: var(--color-text);
}

.breadcrumb .sep {
  opacity: 0.4;
}

/* Tool Cards */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  padding-bottom: 80px;
}

.tool-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform 0.2s, border-color 0.2s;
}

.tool-card:hover {
  transform: translateY(-2px);
  border-color: var(--color-primary);
}

.tool-card h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.tool-card p {
  color: var(--color-text-muted);
  font-size: 0.88rem;
}

/* Tool Page */
.tool-container {
  padding: 40px 0 80px;
}

.tool-container h1 {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 24px;
}

/* Footer */
.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 24px 0;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

/* Utility */
.badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-green {
  background: rgba(52, 211, 153, 0.12);
  color: var(--color-accent-green);
}

.badge-blue {
  background: rgba(96, 165, 250, 0.12);
  color: var(--color-accent-blue);
}

.badge-orange {
  background: rgba(251, 146, 60, 0.12);
  color: var(--color-accent-orange);
}

.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--color-text-muted);
}

.empty-state p {
  font-size: 1rem;
}

/* Tool Page Sections */
.tool-box {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  margin-top: 24px;
}

.tool-box h2 {
  font-size: 1.2rem;
  margin-bottom: 16px;
}

.tool-box input[type="text"],
.tool-box input[type="number"],
.tool-box textarea,
.tool-box select {
  width: 100%;
  padding: 10px 14px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  color: var(--color-text);
  font-size: 0.95rem;
  margin-bottom: 12px;
}

.tool-box input:focus,
.tool-box textarea:focus,
.tool-box select:focus {
  outline: none;
  border-color: var(--color-primary);
}

.tool-box button {
  padding: 10px 20px;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}

.tool-box button:hover {
  background: var(--color-primary-hover);
}

main.container section {
  margin-top: 32px;
}

main.container section h2 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 10px;
}

main.container section h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-top: 16px;
  margin-bottom: 6px;
}

main.container section p,
main.container section ol,
main.container section ul {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

main.container section ol,
main.container section ul {
  padding-left: 20px;
}

main.container section ol li,
main.container section ul li {
  margin-bottom: 6px;
}

.related-tools {
  padding-bottom: 40px;
}

.related-tools a {
  display: block;
  margin: 8px 0;
  color: var(--color-primary);
  font-size: 0.95rem;
}

.related-tools a:hover {
  color: var(--color-primary-hover);
}

/* Search Toggle Button */
.search-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: 6px 10px;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: border-color 0.2s, color 0.2s;
}

.search-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-text);
}

.search-shortcut {
  font-size: 0.65rem;
  padding: 2px 5px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 3px;
  color: var(--color-text-muted);
  font-family: inherit;
  line-height: 1;
  margin-left: 2px;
}

/* Search Overlay */
.search-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  padding: 80px 20px 20px;
  align-items: flex-start;
  justify-content: center;
}

.search-overlay.open {
  display: flex;
}

.search-modal {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  width: 100%;
  max-width: 560px;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
  overflow: hidden;
}

.search-input-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--color-border);
}

.search-icon {
  flex-shrink: 0;
  color: var(--color-text-muted);
}

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

.search-input::placeholder {
  color: var(--color-text-muted);
  opacity: 0.5;
}

.search-kbd {
  font-size: 0.7rem;
  padding: 3px 7px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  color: var(--color-text-muted);
  font-family: inherit;
  line-height: 1;
}

.search-results {
  max-height: 400px;
  overflow-y: auto;
  padding: 6px 0;
}

.search-group-label {
  padding: 10px 18px 4px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--color-text-muted);
  opacity: 0.6;
}

.search-result-item a {
  display: block;
  padding: 10px 18px;
  text-decoration: none;
  transition: background 0.1s;
}

.search-result-item a:hover,
.search-result-item.selected a {
  background: var(--color-surface-hover);
}

.search-result-name {
  display: inline;
  font-weight: 600;
  color: var(--color-text);
  font-size: 0.95rem;
}

.search-result-cat {
  display: inline;
  margin-left: 8px;
  font-size: 0.75rem;
  padding: 2px 8px;
  background: rgba(108, 99, 255, 0.1);
  border-radius: 10px;
  color: var(--color-primary);
  vertical-align: middle;
}

.search-result-desc {
  display: block;
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-top: 2px;
  line-height: 1.4;
}

.search-empty {
  padding: 24px 18px;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 640px) {
  .hero h1 {
    font-size: 2rem;
  }

  .categories-grid,
  .tools-grid {
    grid-template-columns: 1fr;
  }

  .site-nav {
    gap: 10px;
    font-size: 0.8rem;
  }

  .search-shortcut {
    display: none;
  }

  .search-overlay {
    padding: 40px 12px 12px;
  }

  .search-modal {
    max-width: 100%;
  }

  .search-results {
    max-height: 60vh;
  }
}