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

:root {
  --primary: #4f7df9;
  --primary-dark: #3a63d4;
  --primary-light: #e8efff;
  --primary-gradient: linear-gradient(135deg, #4f7df9, #7b5cf6);
  --bg: #f0f2f5;
  --card-bg: #ffffff;
  --text: #1a1a2e;
  --text-secondary: #6b7280;
  --text-muted: #9ca3af;
  --border: #e5e7eb;
  --border-light: #f3f4f6;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.1);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 16px;
  --sidebar-w: 260px;
  --header-h: 64px;
  --transition: 0.2s ease;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.6;
  min-height: 100vh;
}

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

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 24px;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--primary-gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
  box-shadow: 0 2px 8px rgba(79, 125, 249, 0.3);
}

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

.header-search {
  flex: 1;
  max-width: 480px;
  margin: 0 24px;
  position: relative;
}

.header-search input {
  width: 100%;
  height: 40px;
  padding: 0 16px 0 40px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--bg);
  font-size: 14px;
  color: var(--text);
  outline: none;
  transition: all var(--transition);
}

.header-search input:focus {
  border-color: var(--primary);
  background: #fff;
  box-shadow: 0 0 0 3px rgba(79, 125, 249, 0.1);
}

.header-search .search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 16px;
}

.search-results {
  position: absolute;
  top: 48px;
  left: 0;
  right: 0;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  max-height: 320px;
  overflow-y: auto;
  display: none;
  z-index: 200;
}

.search-results.active { display: block; }

.search-result-item {
  padding: 10px 16px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 1px solid var(--border-light);
  transition: background var(--transition);
}

.search-result-item:hover { background: var(--primary-light); }
.search-result-item:last-child { border-bottom: none; }
.search-result-item .sr-icon { font-size: 18px; }
.search-result-item .sr-name { font-weight: 500; }
.search-result-item .sr-cat { font-size: 12px; color: var(--text-muted); margin-left: auto; }

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
}

.header-link {
  font-size: 14px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: color var(--transition);
}
.header-link:hover { color: var(--primary); }

/* ===== Layout ===== */
.layout {
  display: flex;
  padding-top: var(--header-h);
  min-height: 100vh;
}

/* ===== Sidebar ===== */
.sidebar {
  width: var(--sidebar-w);
  position: fixed;
  top: var(--header-h);
  left: 0;
  bottom: 0;
  background: var(--card-bg);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  z-index: 50;
  padding: 16px 0;
}

.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.sidebar-category {
  margin-bottom: 8px;
}

.sidebar-category-title {
  padding: 8px 20px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.sidebar-item {
  padding: 9px 20px 9px 44px;
  font-size: 14px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
  position: relative;
}

.sidebar-item:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.sidebar-item.active {
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 600;
}

.sidebar-item.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--primary);
}

.sidebar-item .si-icon {
  position: absolute;
  left: 20px;
  font-size: 16px;
  width: 18px;
  text-align: center;
}

/* ===== Main Content ===== */
.main {
  flex: 1;
  margin-left: var(--sidebar-w);
  padding: 24px 32px;
  min-width: 0;
}

/* ===== Tool Workspace ===== */
.tool-header {
  margin-bottom: 20px;
}

.tool-header h1 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.tool-header h1 .tool-emoji { font-size: 22px; }

.tool-header .tool-desc {
  color: var(--text-secondary);
  font-size: 14px;
}

.tool-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
}

.tool-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
  align-items: center;
}

.tool-toolbar-group {
  display: flex;
  gap: 6px;
  align-items: center;
  flex-wrap: wrap;
}

.tool-toolbar-divider {
  width: 1px;
  height: 24px;
  background: var(--border);
  margin: 0 4px;
}

/* ===== Buttons ===== */
.btn {
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--card-bg);
  color: var(--text);
  font-size: 13px;
  cursor: pointer;
  transition: all var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
}

.btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.btn-primary:hover {
  background: var(--primary-dark);
  color: #fff;
}

.btn-danger {
  color: var(--danger);
  border-color: var(--border);
}

.btn-danger:hover {
  background: #fef2f2;
  border-color: var(--danger);
  color: var(--danger);
}

.btn-success {
  color: var(--success);
  border-color: var(--border);
}

.btn-success:hover {
  background: #ecfdf5;
  border-color: var(--success);
  color: var(--success);
}

.btn-sm {
  padding: 5px 10px;
  font-size: 12px;
}

.btn-icon {
  padding: 8px;
  width: 34px;
  height: 34px;
  justify-content: center;
}

/* ===== Textarea ===== */
.textarea-wrapper {
  position: relative;
}

textarea {
  width: 100%;
  min-height: 180px;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: "SF Mono", "Fira Code", "Consolas", "Microsoft YaHei", monospace;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text);
  background: #fafafa;
  outline: none;
  resize: vertical;
  transition: all var(--transition);
}

textarea:focus {
  border-color: var(--primary);
  background: #fff;
  box-shadow: 0 0 0 3px rgba(79, 125, 249, 0.1);
}

textarea.output {
  background: #f8f9fa;
  color: #333;
}

.textarea-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.textarea-label .char-count {
  font-weight: 400;
  font-size: 12px;
  color: var(--text-muted);
}

/* ===== Two Column Layout ===== */
.dual-pane {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.dual-pane .pane {
  display: flex;
  flex-direction: column;
}

.action-bar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  margin: 12px 0;
}

/* ===== Info Box ===== */
.info-box {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 13px;
  color: #1e40af;
  margin-bottom: 16px;
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.info-box.warning {
  background: #fffbeb;
  border-color: #fde68a;
  color: #92400e;
}

.info-box.success {
  background: #ecfdf5;
  border-color: #a7f3d0;
  color: #065f46;
}

/* ===== Stats Grid ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.stat-card {
  background: var(--bg);
  border-radius: var(--radius-sm);
  padding: 16px;
  text-align: center;
  border: 1px solid var(--border-light);
}

.stat-card .stat-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.2;
}

.stat-card .stat-label {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ===== Checkbox & Radio ===== */
.checkbox-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.checkbox-item {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  font-size: 14px;
  color: var(--text-secondary);
}

.checkbox-item input {
  width: 16px;
  height: 16px;
  accent-color: var(--primary);
  cursor: pointer;
}

.radio-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.radio-item {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  font-size: 14px;
  color: var(--text-secondary);
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  transition: all var(--transition);
}

.radio-item:hover { border-color: var(--primary); color: var(--primary); }

.radio-item input { accent-color: var(--primary); }

.radio-item.active {
  background: var(--primary-light);
  border-color: var(--primary);
  color: var(--primary);
}

/* ===== Select ===== */
select {
  padding: 7px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--card-bg);
  font-size: 13px;
  color: var(--text);
  cursor: pointer;
  outline: none;
  transition: all var(--transition);
}

select:focus { border-color: var(--primary); }

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text);
  color: #fff;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 14px;
  z-index: 9999;
  opacity: 0;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-lg);
  pointer-events: none;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* ===== Footer ===== */
.footer {
  margin-left: var(--sidebar-w);
  padding: 24px 32px;
  border-top: 1px solid var(--border);
  background: var(--card-bg);
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
}

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

/* ===== Home / Landing ===== */
.home-hero {
  text-align: center;
  padding: 40px 20px 20px;
  margin-bottom: 28px;
}

.home-hero h1 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 12px;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

.home-search {
  max-width: 560px;
  margin: 24px auto 0;
  position: relative;
}

.home-search input {
  width: 100%;
  height: 52px;
  padding: 0 20px 0 52px;
  border: 2px solid var(--border);
  border-radius: 26px;
  font-size: 16px;
  outline: none;
  background: var(--card-bg);
  box-shadow: var(--shadow);
  transition: all var(--transition);
}

.home-search input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(79, 125, 249, 0.1);
}

.home-search .search-icon {
  position: absolute;
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  color: var(--text-muted);
}

.tool-categories {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.tool-category {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  transition: all var(--transition);
}

.tool-category:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.tool-category-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-light);
}

.tool-category-header .tc-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
}

.tool-category-header .tc-title {
  font-size: 16px;
  font-weight: 700;
}

.tool-category-header .tc-count {
  font-size: 12px;
  color: var(--text-muted);
  margin-left: auto;
}

.tool-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.tool-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border-radius: 8px;
  font-size: 13px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
}

.tool-link:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.tool-link .tl-icon { font-size: 16px; }

/* ===== FAQ ===== */
.faq-section {
  margin-top: 40px;
}

.faq-section h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 16px;
  text-align: center;
}

.faq-item {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 12px;
  box-shadow: var(--shadow-sm);
}

.faq-item h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.faq-item p {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.8;
}

/* ===== Diff View ===== */
.diff-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  min-height: 200px;
}

.diff-pane {
  padding: 12px;
  font-family: monospace;
  font-size: 13px;
  overflow-x: auto;
  max-height: 400px;
  overflow-y: auto;
}

.diff-pane:first-child {
  border-right: 1px solid var(--border);
}

.diff-pane-title {
  padding: 8px 12px;
  background: var(--bg);
  font-weight: 600;
  font-size: 13px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
}

.diff-line {
  padding: 1px 8px;
  white-space: pre;
  min-height: 22px;
}

.diff-line.added { background: #dcfce7; color: #166534; }
.diff-line.removed { background: #fee2e2; color: #991b1b; }
.diff-line.unchanged { color: var(--text-muted); }

.diff-line-num {
  display: inline-block;
  width: 36px;
  color: var(--text-muted);
  font-size: 11px;
  user-select: none;
}

/* ===== Responsive ===== */
.sidebar-toggle {
  display: none;
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 48px;
  height: 48px;
  background: var(--primary);
  border-radius: 50%;
  color: #fff;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  cursor: pointer;
  z-index: 60;
  box-shadow: var(--shadow-lg);
}

@media (max-width: 900px) {
  .sidebar {
    transform: translateX(-100%);
    transition: transform 0.3s ease;
  }
  .sidebar.open { transform: translateX(0); }
  .main, .footer { margin-left: 0; }
  .dual-pane { grid-template-columns: 1fr; }
  .header-search { max-width: 200px; margin: 0 12px; }
  .home-hero h1 { font-size: 24px; }
  .home-hero p { font-size: 14px; }
  .tool-categories { grid-template-columns: 1fr; }
  .main { padding: 16px; }
  .sidebar-toggle { display: flex; }
}

@media (max-width: 600px) {
  .header-search { display: none; }
  .header { padding: 0 12px; }
  .tool-grid { grid-template-columns: 1fr; }
  .diff-container { grid-template-columns: 1fr; }
  .diff-pane:first-child { border-right: none; border-bottom: 1px solid var(--border); }
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #94a3b8; }

/* ===== Loading Spinner ===== */
.spinner {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ===== Empty State ===== */
.empty-state {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-muted);
}

.empty-state .es-icon {
  font-size: 48px;
  margin-bottom: 12px;
}

/* ===== Badge ===== */
.badge {
  display: inline-block;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 600;
  border-radius: 10px;
  background: var(--primary-light);
  color: var(--primary);
}

.badge.hot { background: #fef3c7; color: #92400e; }
.badge.new { background: #dcfce7; color: #166534; }

/* ===== 多页面：链接样式重置 ===== */
a.sidebar-item, a.tool-link, a.search-result-item {
  text-decoration: none;
  color: inherit;
}

a.sidebar-item:hover, a.tool-link:hover {
  color: var(--primary, #4f7df9);
}

/* ===== 面包屑 ===== */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-muted, #999);
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.breadcrumb a {
  color: var(--text-secondary, #666);
  text-decoration: none;
}
.breadcrumb a:hover {
  color: var(--primary, #4f7df9);
}
.breadcrumb .sep {
  color: var(--border-dark, #ccc);
}
.breadcrumb .current {
  color: var(--text-primary, #333);
  font-weight: 500;
}

/* ===== 工具页头部 ===== */
.tool-page-header {
  margin-bottom: 20px;
}
.tool-page-header h1 {
  font-size: 24px;
  margin: 0 0 8px 0;
}
.tool-page-header .tool-desc {
  color: var(--text-secondary, #666);
  font-size: 14px;
  margin: 0;
}

/* ===== 相关工具 ===== */
.related-tools {
  margin-top: 32px;
  padding-top: 20px;
  border-top: 1px solid var(--border-light, #eee);
}
.related-title {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-primary, #333);
}