/* ===================== Reset & Base ===================== */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
    'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  background: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.5;
  transition: background 0.3s, color 0.3s;
}
a { color: inherit; text-decoration: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; color: inherit; }

:root {
  --bg-body: #f8fafc;
  --bg-sidebar: #ffffff;
  --bg-card: #ffffff;
  --bg-hover: #f1f5f9;
  --bg-active: #eef2ff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --border-color: #e2e8f0;
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.08);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
}

body.dark {
  --bg-body: #0f172a;
  --bg-sidebar: #1e293b;
  --bg-card: #1e293b;
  --bg-hover: #334155;
  --bg-active: #1e3a5f;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border-color: #334155;
  --primary: #818cf8;
  --primary-hover: #a5b4fc;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.25);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.3);
}

/* ===================== Layout ===================== */
html, body {
  height: 100%;
  margin: 0;
}
body {
  overflow-x: hidden;
}
.sidebar {
  position: fixed;
  left: 0; top: 0;
  width: 280px;
  height: 100vh;
  height: 100dvh;
  max-height: -webkit-fill-available;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  z-index: 100;
  overflow: hidden;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
}

.sidebar-scroll {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
}

.sidebar-header {
  padding: 24px 20px 16px;
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
}
.logo-icon {
  width: 36px; height: 36px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #6366f1, #a855f7);
  border-radius: 10px;
  font-size: 20px;
  color: white;
}
.logo-sub {
  margin-top: 6px;
  font-size: 12px;
  color: var(--text-muted);
  padding-left: 46px;
}

.sidebar-search {
  padding: 14px 16px;
  flex-shrink: 0;
  border-bottom: 1px solid var(--border-color);
}
.search-bar {
  display: flex;
  align-items: center;
  background: var(--bg-body);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 0 12px;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.search-bar:focus-within {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.15);
}
.search-bar .icon {
  color: var(--text-muted);
  font-size: 14px;
  margin-right: 8px;
}
.search-bar input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  padding: 10px 0;
  font-size: 13px;
  color: var(--text-primary);
}
.search-clear {
  width: 22px; height: 22px;
  border-radius: 50%;
  display: none;
  align-items: center;
  justify-content: center;
  background: var(--text-muted);
  color: white;
  font-size: 14px;
  line-height: 1;
}
.search-clear:hover { background: var(--text-secondary); }

.sidebar-section {
  padding: 8px 12px;
}
.sidebar-section + .sidebar-section {
  border-top: 1px solid var(--border-color);
  padding-top: 12px;
  margin-top: 4px;
}

.sidebar-label {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  padding: 8px 8px 6px;
}

.side-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.side-nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 9px 10px;
  border-radius: 8px;
  font-size: 13.5px;
  color: var(--text-secondary);
  text-align: left;
  transition: all 0.15s;
}
.side-nav-item:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}
.side-nav-item.active {
  background: var(--bg-active);
  color: var(--primary);
  font-weight: 600;
}
.s-icon {
  width: 28px; height: 28px;
  border-radius: 7px;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px;
  flex-shrink: 0;
}
.s-name { flex: 1; }
.s-cnt {
  font-size: 11px;
  color: var(--text-muted);
  background: var(--bg-body);
  padding: 2px 7px;
  border-radius: 10px;
  font-weight: 500;
}
.side-nav-item.active .s-cnt {
  background: rgba(99,102,241,0.15);
  color: var(--primary);
}

/* Category tags in sidebar */
.cat-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 4px 8px 12px;
}
.cat-btn {
  padding: 5px 11px;
  font-size: 11.5px;
  border-radius: 14px;
  background: var(--bg-body);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  transition: all 0.15s;
  white-space: nowrap;
}
.cat-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}
.cat-btn.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.sidebar-footer {
  padding: 14px 16px;
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex-shrink: 0;
  background: var(--bg-sidebar);
}
.footer-stats {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 11px;
  color: var(--text-muted);
}
.footer-stats strong { color: var(--text-secondary); }
.theme-toggle-side {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px;
  border-radius: 8px;
  font-size: 12px;
  color: var(--text-secondary);
  background: var(--bg-body);
  border: 1px solid var(--border-color);
  transition: all 0.15s;
}
.theme-toggle-side:hover {
  border-color: var(--primary);
  color: var(--primary);
}

/* ===================== Main Content ===================== */
.main-content {
  margin-left: 280px;
  min-height: 100vh;
  padding: 28px 32px;
  max-width: 100%;
}

.content-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 20px;
  gap: 20px;
  flex-wrap: wrap;
}
.content-header h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.3px;
}
.page-subtitle {
  margin-top: 4px;
  font-size: 13.5px;
  color: var(--text-secondary);
}
.count-badge {
  padding: 6px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  font-size: 12.5px;
  color: var(--text-secondary);
  font-weight: 500;
  white-space: nowrap;
}

/* Category tabs in main area */
.cat-tabs-section {
  margin-bottom: 20px;
  overflow-x: auto;
  padding-bottom: 4px;
}
.cat-tabs {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

/* ===================== Tools Grid ===================== */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 14px;
  margin-bottom: 32px;
}

.tool-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px 16px 16px;
  transition: all 0.2s ease;
  cursor: pointer;
  animation: fadeIn 0.3s ease-out backwards;
  display: block;
}
.tool-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}
.tool-icon {
  width: 44px; height: 44px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 12px;
}
.tool-name {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 5px;
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  min-height: 38px;
}
.tool-desc {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  min-height: 34px;
}
.fav-btn {
  position: absolute;
  top: 10px; right: 10px;
  width: 26px; height: 26px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  color: var(--text-muted);
  opacity: 0;
  transition: all 0.15s;
  background: var(--bg-body);
}
.tool-card:hover .fav-btn { opacity: 1; }
.fav-btn:hover { color: #f59e0b; transform: scale(1.1); }
.fav-btn.faved { opacity: 1; color: #f59e0b; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===================== Loading ===================== */
.loading-grid {
  grid-column: 1 / -1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 20px;
  gap: 14px;
}
.loading-spinner {
  width: 36px; height: 36px;
  border: 3px solid var(--border-color);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
.loading-text {
  font-size: 13px;
  color: var(--text-secondary);
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ===================== Empty State ===================== */
.empty-state {
  grid-column: 1 / -1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 60px 20px;
  text-align: center;
}
.empty-icon { font-size: 48px; margin-bottom: 14px; opacity: 0.6; }
.empty-state > div:nth-child(2) {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 4px;
}
.empty-hint {
  font-size: 12.5px;
  color: var(--text-muted);
}

/* ===================== Section Title ===================== */
.section-title {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 20px 0 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}
.section-title .line {
  flex: 1;
  height: 1px;
  background: var(--border-color);
}

/* ===================== Stats Dashboard ===================== */
.stats-dashboard {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 10px;
  margin-bottom: 20px;
}
.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px;
  text-align: center;
  transition: all 0.2s;
}
.stat-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}
.stat-num {
  font-size: 22px;
  font-weight: 700;
  color: var(--primary);
}
.stat-label {
  font-size: 11.5px;
  color: var(--text-muted);
  margin-top: 2px;
}

/* ===================== Jump Top ===================== */
.jump-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 42px; height: 42px;
  border-radius: 50%;
  background: var(--primary);
  color: white;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  pointer-events: none;
  transition: all 0.25s;
  z-index: 50;
}
.jump-top:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* ===================== Footer ===================== */
.main-footer {
  text-align: center;
  padding: 30px 0 10px;
  color: var(--text-muted);
  font-size: 12px;
  border-top: 1px solid var(--border-color);
  margin-top: 20px;
}

body.sidebar-open {
  overflow: hidden;
  position: fixed;
  width: 100%;
  height: 100%;
}

/* ===================== Mobile Top Bar ===================== */
.mobile-topbar {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 52px;
  background: var(--bg-sidebar);
  border-bottom: 1px solid var(--border-color);
  padding: 0 14px;
  align-items: center;
  justify-content: space-between;
  z-index: 101;
}
.menu-btn {
  font-size: 20px;
  padding: 8px;
  color: var(--text-primary);
}
.mobile-logo {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
}
.theme-btn-mobile {
  font-size: 18px;
  padding: 8px;
}
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 99;
}
.sidebar-overlay.show { display: block; }

/* ===================== Responsive ===================== */
@media (max-width: 768px) {
  .mobile-topbar { display: flex; }
  
  .sidebar {
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    padding-top: 52px;
    box-shadow: 4px 0 20px rgba(0,0,0,0.15);
  }
  .sidebar.open { 
    transform: translateX(0); 
  }
  .sidebar-overlay {
    transition: opacity 0.3s;
  }
  .sidebar-overlay.show {
    display: block;
    opacity: 1;
  }
  
  .main-content {
    margin-left: 0;
    padding: 72px 14px 24px;
  }
  
  .content-header {
    margin-bottom: 14px;
    gap: 10px;
  }
  .content-header h2 { font-size: 19px; }
  .page-subtitle { font-size: 12.5px; }
  .count-badge { padding: 5px 10px; font-size: 11.5px; }
  
  /* 分类标签横向滚动，不换行 */
  .cat-tabs-section {
    margin-bottom: 14px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 6px;
    margin-left: -14px;
    margin-right: -14px;
    padding-left: 14px;
    padding-right: 14px;
  }
  .cat-tabs {
    flex-wrap: nowrap;
    gap: 8px;
  }
  .cat-tabs .cat-btn {
    flex-shrink: 0;
    white-space: nowrap;
    font-size: 12.5px;
    padding: 7px 14px;
  }
  
  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }
  .tool-card { 
    padding: 14px 12px 12px; 
  }
  .tool-icon { width: 36px; height: 36px; font-size: 18px; margin-bottom: 8px; border-radius: 8px; }
  .tool-name { font-size: 12.5px; min-height: 32px; line-height: 1.3; }
  .tool-desc { font-size: 10.5px; min-height: 26px; line-height: 1.35; }
  .fav-btn { opacity: 1; width: 24px; height: 24px; top: 8px; right: 8px; }
  
  /* 侧边栏内分类标签 */
  .cat-tags {
    gap: 5px;
    padding: 4px 4px 12px;
  }
  .cat-tags .cat-btn {
    font-size: 11px;
    padding: 4px 9px;
  }
  
  /* 回到顶部 */
  .jump-top {
    right: 16px;
    bottom: 20px;
    width: 38px;
    height: 38px;
    font-size: 16px;
  }
  
  /* 底部 */
  .main-footer {
    padding: 20px 0 10px;
    font-size: 11px;
  }
  
  /* Stats dashboard */
  .stats-dashboard {
    gap: 8px;
    margin-bottom: 14px;
  }
  .stat-card { padding: 10px; }
  .stat-num { font-size: 18px; }
  .stat-label { font-size: 10.5px; }
  
  /* sidebar scroll 优化 */
  .sidebar-scroll {
    -webkit-overflow-scrolling: touch;
  }
}

@media (max-width: 480px) {
  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
  }
  .tool-card {
    padding: 12px 10px 10px;
  }
  .main-content {
    padding: 68px 10px 20px;
  }
  .content-header h2 { font-size: 18px; }
}

@media (max-width: 360px) {
  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
  }
  .tool-card {
    padding: 10px 8px 8px;
  }
  .tool-name { font-size: 12px; min-height: 30px; }
  .tool-desc { display: none; }
}

/* ===================== Scrollbar ===================== */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }