:root {
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --primary-light: rgba(99, 102, 241, 0.1);
  --danger: #ef4444;
  --danger-hover: #dc2626;
  --success: #22c55e;
  --warning: #f59e0b;

  --bg: #f8fafc;
  --bg-card: #ffffff;
  --bg-input: #f1f5f9;
  --bg-hover: #e2e8f0;

  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;

  --border: #e2e8f0;
  --border-light: #f1f5f9;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
  --shadow-card: 0 1px 3px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.06);

  --radius-sm: 6px;
  --radius: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;

  --header-height: 64px;
  --max-width: 1200px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg: #0f172a;
  --bg-card: #1e293b;
  --bg-input: #334155;
  --bg-hover: #475569;

  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --border: #334155;
  --border-light: #1e293b;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 10px 15px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 20px 25px rgba(0, 0, 0, 0.5);
  --shadow-card: 0 1px 3px rgba(0,0,0,0.2), 0 4px 12px rgba(0,0,0,0.15);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: background var(--transition), border-color var(--transition);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  flex-shrink: 0;
}

.logo-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius);
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  overflow-x: auto;
  flex: 1;
  scrollbar-width: none;
}

.header-nav::-webkit-scrollbar { display: none; }

.header-nav-item {
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--text-secondary);
  white-space: nowrap;
  transition: all var(--transition);
}

.header-nav-item:hover,
.header-nav-item.active {
  color: var(--primary);
  background: var(--primary-light);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-input);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  transition: all var(--transition);
}

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

.lang-switcher {
  position: relative;
}

.lang-toggle {
  height: 36px;
  padding: 0 10px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-input);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 13px;
  transition: all var(--transition);
  white-space: nowrap;
}

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

.lang-dropdown {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(0,0,0,0.12);
  min-width: 120px;
  z-index: 1000;
  display: none;
  overflow: hidden;
}

.lang-dropdown.show {
  display: block;
}

.lang-option {
  display: block;
  width: 100%;
  padding: 8px 14px;
  border: none;
  background: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 13px;
  text-align: left;
  transition: all var(--transition);
}

.lang-option:hover {
  background: var(--bg-hover);
  color: var(--primary);
}

.lang-option.active {
  color: var(--primary);
  font-weight: 600;
}

.main {
  padding-top: var(--header-height);
  min-height: calc(100vh - 200px);
}

.hero {
  padding: 48px 0 32px;
  text-align: center;
}

.hero-title {
  font-size: 32px;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.hero-title span {
  background: linear-gradient(135deg, var(--primary), #a855f7);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 24px;
}

.search-box {
  max-width: 520px;
  margin: 0 auto;
  position: relative;
}

.search-box input {
  width: 100%;
  padding: 12px 16px 12px 44px;
  border-radius: var(--radius-lg);
  border: 2px solid var(--border);
  background: var(--bg-card);
  color: var(--text-primary);
  font-size: 15px;
  outline: none;
  transition: all var(--transition);
}

.search-box input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

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

.search-box i {
  font-size: 16px;
}

.search-btn {
  position: absolute;
  left: 0;
  top: 0;
  width: 44px;
  height: 100%;
  border: none;
  background: none;
  cursor: pointer;
  color: var(--text-muted);
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition);
  z-index: 1;
}

.search-btn:hover {
  color: var(--primary);
}

.category-tabs-wrapper {
  position: sticky;
  top: var(--header-height);
  background: var(--bg);
  z-index: 100;
  border-bottom: 1px solid var(--border);
  transition: background var(--transition), border-color var(--transition);
}

.category-tabs {
  display: flex;
  gap: 6px;
  padding: 12px 0;
  overflow-x: auto;
  scrollbar-width: none;
}

.category-tabs::-webkit-scrollbar { display: none; }

.category-tab {
  padding: 7px 16px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-card);
  border: 1px solid var(--border);
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
}

.category-tab:hover {
  color: var(--primary);
  border-color: var(--primary);
}

.category-tab.active {
  color: #fff;
  background: var(--primary);
  border-color: var(--primary);
}

.category-tab i {
  font-size: 12px;
}

.tool-section-title-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
  padding-top: 8px;
}

.tool-section-title-bar h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.tool-section-title-bar h2 i {
  color: var(--primary);
  font-size: 18px;
}

.tool-section-title-bar .tool-count {
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 400;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
  margin-bottom: 40px;
}

.tool-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  transition: all var(--transition);
}

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

.tool-card-icon {
  width: 42px;
  height: 42px;
  border-radius: var(--radius);
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.tool-card-info {
  flex: 1;
  min-width: 0;
}

.tool-card-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tool-card-desc {
  font-size: 12px;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 40px 0 20px;
  margin-top: 40px;
  transition: background var(--transition), border-color var(--transition);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 32px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
}

.footer-desc {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.7;
}

.footer-col h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 8px;
}

.footer-col ul li a {
  font-size: 13px;
  color: var(--text-muted);
  transition: color var(--transition);
}

.footer-col ul li a:hover {
  color: var(--primary);
}

.footer-bottom {
  padding-top: 20px;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer-bottom p {
  font-size: 12px;
  color: var(--text-muted);
}

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

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

.toast-container {
  position: fixed;
  top: 80px;
  right: 20px;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  padding: 12px 20px;
  border-radius: var(--radius);
  font-size: 14px;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 8px;
  animation: toastIn 0.3s ease;
  box-shadow: var(--shadow-lg);
}

.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }
.toast.info { background: var(--primary); }

.toast-out { animation: toastOut 0.3s ease forwards; }

@keyframes toastIn {
  from { opacity: 0; transform: translateX(40px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes toastOut {
  from { opacity: 1; transform: translateX(0); }
  to { opacity: 0; transform: translateX(40px); }
}

.no-results {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-muted);
}

.no-results i {
  font-size: 48px;
  margin-bottom: 16px;
  display: block;
}

.no-results p {
  font-size: 16px;
}

@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .header-nav { display: none; }
  .hero-title { font-size: 24px; }
  .hero-desc { font-size: 14px; }
  .hero { padding: 32px 0 20px; }
  .tool-grid {
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 12px;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 480px) {
  .tool-grid {
    grid-template-columns: 1fr;
  }
  .tool-card {
    padding: 12px 14px;
  }
}