@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&family=Work+Sans:wght@300;400;500;600;700&display=swap');

:root {
  --primary: #2563EB;
  --primary-hover: #1D4ED8;
  --primary-light: #DBEAFE;
  --bg: #F8FAFC;
  --bg-card: #FFFFFF;
  --text: #1E293B;
  --text-muted: #64748B;
  --border: #E2E8F0;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -2px rgba(0,0,0,0.04);
  --radius: 12px;
  --radius-sm: 8px;
  --font-heading: 'Outfit', sans-serif;
  --font-body: 'Work Sans', sans-serif;
}

[data-theme="dark"] {
  --primary: #3B82F6;
  --primary-hover: #2563EB;
  --primary-light: #1E3A5F;
  --bg: #0F172A;
  --bg-card: #1E293B;
  --text: #F1F5F9;
  --text-muted: #94A3B8;
  --border: #334155;
  --shadow: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.3);
}

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

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background 0.3s, color 0.3s;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.3;
}

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  gap: 24px;
  transition: background 0.3s, border-color 0.3s;
}

.logo {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
}

.logo svg { width: 28px; height: 28px; }

.search-box {
  flex: 1;
  max-width: 480px;
  position: relative;
}

.search-box input {
  width: 100%;
  padding: 10px 16px 10px 40px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 0.9rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-box input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.search-box svg {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  color: var(--text-muted);
}

.theme-toggle {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text);
  transition: background 0.2s, border-color 0.2s;
  flex-shrink: 0;
}

.theme-toggle:hover { border-color: var(--primary); }
.theme-toggle svg { width: 20px; height: 20px; }

/* Hero */
.hero {
  text-align: center;
  padding: 64px 24px 48px;
  max-width: 800px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-muted);
}

/* Category Tabs */
.category-tabs {
  display: flex;
  gap: 8px;
  padding: 0 24px;
  max-width: 1200px;
  margin: 0 auto 32px;
  flex-wrap: wrap;
  justify-content: center;
}

.category-tab {
  padding: 8px 20px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-card);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

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

/* Tools Grid */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px;
  padding: 0 24px;
  max-width: 1200px;
  margin: 0 auto 64px;
}

.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-decoration: none;
  color: var(--text);
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: all 0.2s;
  box-shadow: var(--shadow);
}

.tool-card:hover {
  text-decoration: none;
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.tool-card .tool-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  flex-shrink: 0;
}

.tool-card .tool-icon svg { width: 16px; height: 16px; }

.tool-card { padding: 16px; gap: 8px; }

.tool-card h3 {
  font-size: 0.875rem;
  font-weight: 600;
  margin: 0;
}

.tool-card p {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.45;
  margin: 0;
}

.tool-card .tool-category {
  font-size: 0.65rem;
  color: var(--primary);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: auto;
}

/* Category Colors */
.tool-icon.dev { background: #DBEAFE; color: #2563EB; }
.tool-icon.design { background: #F3E8FF; color: #9333EA; }
.tool-icon.text { background: #DCFCE7; color: #16A34A; }
.tool-icon.convert { background: #FEF3C7; color: #D97706; }
.tool-icon.gen { background: #FFE4E6; color: #E11D48; }
.tool-icon.image { background: #CFFAFE; color: #0891B2; }
.tool-icon.net { background: #E0F2FE; color: #0284C7; }
.tool-icon.data { background: #F0FDF4; color: #15803D; }
.tool-icon.geo { background: #EDE9FE; color: #7C3AED; }
.tool-icon.enc { background: #FEE2E2; color: #DC2626; }
.tool-icon.math { background: #FEF9C3; color: #CA8A04; }

[data-theme="dark"] .tool-icon.dev { background: rgba(37,99,235,0.15); color: #60A5FA; }
[data-theme="dark"] .tool-icon.design { background: rgba(147,51,234,0.15); color: #C084FC; }
[data-theme="dark"] .tool-icon.text { background: rgba(22,163,74,0.15); color: #4ADE80; }
[data-theme="dark"] .tool-icon.convert { background: rgba(217,119,6,0.15); color: #FBBF24; }
[data-theme="dark"] .tool-icon.gen { background: rgba(225,29,72,0.15); color: #FB7185; }
[data-theme="dark"] .tool-icon.image { background: rgba(8,145,178,0.15); color: #22D3EE; }
[data-theme="dark"] .tool-icon.net { background: rgba(2,132,199,0.15); color: #38BDF8; }
[data-theme="dark"] .tool-icon.data { background: rgba(21,128,61,0.15); color: #4ADE80; }
[data-theme="dark"] .tool-icon.geo { background: rgba(124,58,237,0.15); color: #A78BFA; }
[data-theme="dark"] .tool-icon.enc { background: rgba(220,38,38,0.15); color: #F87171; }
[data-theme="dark"] .tool-icon.math { background: rgba(202,138,4,0.15); color: #FACC15; }

/* Tool Badge */
.tool-card { position: relative; }
.tool-badge {
  position: absolute;
  top: 8px;
  right: 8px;
  font-size: 0.6rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  background: linear-gradient(135deg, #F97316, #EF4444);
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}
.tool-badge.badge-new {
  background: linear-gradient(135deg, #2563EB, #7C3AED);
}

/* Favorite Button */
.fav-btn {
  position: absolute;
  top: 8px;
  left: 8px;
  width: 20px;
  height: 20px;
  border: none;
  background: none;
  cursor: pointer;
  color: var(--text-muted);
  opacity: 0.4;
  transition: all 0.2s;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2;
}
.fav-btn svg { width: 14px; height: 14px; }
.fav-btn:hover { opacity: 1; color: #F59E0B; }
.fav-btn.active { opacity: 1; color: #F59E0B; }

/* Smart Sections (Favorites & Recent) */
.smart-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 8px;
}
.smart-section h4 {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.smart-section h4 svg { width: 14px; height: 14px; }
.smart-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
}

/* Security Badge */
.security-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.3);
  color: #22C55E;
  font-size: 0.75rem;
  font-weight: 500;
  margin-top: 8px;
}
.security-badge svg { width: 14px; height: 14px; }
[data-theme="dark"] .security-badge { background: rgba(34, 197, 94, 0.1); border-color: rgba(34, 197, 94, 0.3); color: #4ADE80; }

/* Tool Chain */
.tool-chain { margin-top: 16px; position: relative; }
.chain-btn { font-size: 0.8rem !important; padding: 6px 14px !important; }
.chain-menu {
  position: absolute;
  bottom: 100%;
  left: 0;
  margin-bottom: 4px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  padding: 4px;
  z-index: 50;
  min-width: 180px;
}
.chain-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 6px;
  cursor: pointer;
  color: var(--text);
  font-size: 0.85rem;
  text-decoration: none;
  transition: background 0.15s;
}
.chain-item:hover { background: var(--primary-light); color: var(--primary); text-decoration: none; }
.chain-item svg { width: 16px; height: 16px; flex-shrink: 0; }

/* Feedback Widget */
.feedback-widget {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 900;
}
.feedback-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  transition: transform 0.2s;
}
.feedback-btn:hover { transform: scale(1.1); }
.feedback-btn svg { width: 22px; height: 22px; }
.feedback-modal {
  position: fixed;
  bottom: 74px;
  right: 20px;
  width: 320px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 20px;
  z-index: 901;
  display: none;
}
.feedback-modal.show { display: block; }
.feedback-modal h4 { margin-bottom: 8px; font-size: 1rem; }
.feedback-modal p { font-size: 0.8rem; color: var(--text-muted); margin-bottom: 12px; }
.feedback-modal textarea { min-height: 80px; margin-bottom: 12px; }

/* Search shortcut hint */
.search-box::after {
  content: 'Ctrl K';
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.65rem;
  color: var(--text-muted);
  background: var(--border);
  padding: 2px 6px;
  border-radius: 4px;
  opacity: 0.6;
  pointer-events: none;
}
@media (max-width: 640px) {
  .search-box::after { display: none; }
}

/* Tool count */
.tool-count-text {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 24px;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.site-footer a { color: var(--text-muted); margin: 0 8px; }
.site-footer a:hover { color: var(--primary); }

/* Tool Page Layout */
.tool-page { min-height: 100vh; display: flex; flex-direction: column; }
.tool-content { flex: 1; padding: 32px 24px; max-width: 1200px; width: 100%; margin: 0 auto; }

.tool-content h2, .tool-content h3 { color: var(--text); margin-bottom: 12px; }
.tool-content h2 { font-size: 1.4rem; }
.tool-content h3 { font-size: 1.1rem; }
.tool-content p { color: var(--text-muted); font-size: 0.9rem; line-height: 1.6; }
.tool-content label { display: block; font-size: 0.85rem; font-weight: 500; color: var(--text-muted); margin-bottom: 6px; }
.tool-content input[type="text"],
.tool-content input[type="number"],
.tool-content input[type="email"],
.tool-content input[type="url"],
.tool-content input[type="password"],
.tool-content input[type="date"],
.tool-content input[type="time"],
.tool-content input[type="datetime-local"],
.tool-content input[type="color"],
.tool-content input[type="search"] {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  background: var(--bg-card);
  color: var(--text);
  transition: border-color 0.2s, box-shadow 0.2s;
}
.tool-content input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}
.tool-content textarea {
  width: 100%;
  min-height: 120px;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.9rem;
  font-family: monospace;
  line-height: 1.5;
  background: var(--bg-card);
  color: var(--text);
  resize: vertical;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.tool-content textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}
.tool-content select {
  padding: 10px 32px 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  background: var(--bg-card) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2394A3B8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E") no-repeat right 12px center;
  background-size: 12px;
  color: var(--text);
  cursor: pointer;
  appearance: none;
  transition: border-color 0.2s;
}
.tool-content select:focus {
  outline: none;
  border-color: var(--primary);
}
.tool-content table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}
.tool-content th, .tool-content td {
  padding: 10px 12px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.tool-content th {
  font-weight: 600;
  color: var(--text-muted);
  background: var(--bg);
}
.tool-content tr:hover td {
  background: rgba(37, 99, 235, 0.04);
}
[data-theme="dark"] .tool-content tr:hover td {
  background: rgba(59, 130, 246, 0.08);
}

.tab-btn {
  padding: 8px 20px;
  border: none;
  background: none;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: color 0.2s, border-color 0.2s;
}
.tab-btn:hover { color: var(--text); }
.tab-btn.active { color: var(--primary); border-bottom-color: var(--primary); }
.tab-content { display: none; }
.tab-content.active { display: block; }

[data-theme="dark"] .tool-content input,
[data-theme="dark"] .tool-content textarea,
[data-theme="dark"] .tool-content select {
  background: #1E293B;
  border-color: #334155;
}
[data-theme="dark"] .tool-content input:focus,
[data-theme="dark"] .tool-content textarea:focus {
  border-color: #3B82F6;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}
[data-theme="dark"] .tool-content th {
  background: #0F172A;
}


.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 24px;
  text-decoration: none;
}

.back-link:hover { color: var(--primary); text-decoration: none; }
.back-link svg { width: 16px; height: 16px; }

.tool-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 32px;
}

.tool-header .tool-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius);
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  flex-shrink: 0;
}

.tool-header .tool-icon svg { width: 28px; height: 28px; }
.tool-header h1 { font-size: 1.75rem; }
.tool-header p { color: var(--text-muted); font-size: 0.95rem; }

/* Tool Panel */
.tool-panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
}

/* Two Column Layout */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

@media (max-width: 768px) {
  .two-col { grid-template-columns: 1fr; }
}

/* Form Elements */
textarea, input[type="text"], input[type="number"], select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 0.9rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

textarea {
  min-height: 200px;
  resize: vertical;
  font-family: 'Courier New', monospace;
  line-height: 1.5;
}

textarea:focus, input:focus, select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 6px;
  color: var(--text);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

.btn:hover { border-color: var(--primary); color: var(--primary); text-decoration: none; }

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

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

.btn svg { width: 16px; height: 16px; }

.btn-group {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 16px;
}

/* Output Area */
.output-area {
  position: relative;
  min-height: 200px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  overflow-x: auto;
}

.output-area pre {
  font-family: 'Courier New', monospace;
  font-size: 0.875rem;
  white-space: pre-wrap;
  word-break: break-all;
  color: var(--text);
}

.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-muted);
  transition: all 0.2s;
}

.copy-btn:hover { border-color: var(--primary); color: var(--primary); }
.copy-btn svg { width: 16px; height: 16px; }

/* Stat Cards */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 16px;
  margin-top: 20px;
}

.stat-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 20px;
  text-align: center;
}

.stat-card .stat-value {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
}

.stat-card .stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Checkbox */
.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.checkbox-item {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.checkbox-item input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
  cursor: pointer;
}

/* Range Slider */
input[type="range"] {
  width: 100%;
  accent-color: var(--primary);
  cursor: pointer;
}

/* Color Preview */
.color-preview {
  width: 100%;
  height: 80px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  margin-bottom: 16px;
}

/* Password Strength */
.strength-bar {
  height: 6px;
  border-radius: 3px;
  background: var(--border);
  overflow: hidden;
  margin-top: 12px;
}

.strength-bar .strength-fill {
  height: 100%;
  border-radius: 3px;
  transition: width 0.3s, background 0.3s;
}

.strength-label {
  font-size: 0.8rem;
  font-weight: 500;
  margin-top: 6px;
}

/* Result Display */
.result-box {
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  word-break: break-all;
  margin-top: 8px;
}

.result-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.result-row .result-label {
  font-weight: 500;
  min-width: 60px;
  font-size: 0.875rem;
}

.result-row .result-value {
  flex: 1;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  color: var(--primary);
}

.result-row .copy-btn-inline {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  padding: 4px;
  border-radius: 4px;
  transition: color 0.2s;
}

.result-row .copy-btn-inline:hover { color: var(--primary); }
.result-row .copy-btn-inline svg { width: 16px; height: 16px; }

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text);
  color: var(--bg);
  padding: 10px 24px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  z-index: 1000;
  opacity: 0;
  transition: transform 0.3s, opacity 0.3s;
  pointer-events: none;
}

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

/* Responsive */
@media (max-width: 640px) {
  .site-header { padding: 0 16px; gap: 12px; }
  .search-box { max-width: none; }
  .hero { padding: 40px 16px 32px; }
  .hero h1 { font-size: 2rem; }
  .hero p { font-size: 1rem; }
  .tools-grid { padding: 0 16px; }
  .tool-content { padding: 16px; }
  .tool-panel { padding: 16px; }
  .category-tabs { padding: 0 16px; }
  .btn-group { flex-direction: column; }
  .btn { width: 100%; }
}

/* Utility */
.text-center { text-align: center; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }
.flex { display: flex; }
.items-center { align-items: center; }
.gap-8 { gap: 8px; }
.gap-12 { gap: 12px; }
.gap-16 { gap: 16px; }
.flex-wrap { flex-wrap: wrap; }
.hidden { display: none; }

/* QR Canvas */
#qr-canvas { display: block; margin: 0 auto; }

/* Select Group */
.select-group {
  display: flex;
  gap: 12px;
  align-items: end;
  flex-wrap: wrap;
}

.select-group > div { flex: 1; min-width: 120px; }

/* ===== v5 Additions ===== */

/* PWA Install Banner */
.pwa-banner {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 -4px 12px rgba(0,0,0,0.08);
  z-index: 900;
  transform: translateY(100%);
  transition: transform 0.3s;
}
.pwa-banner.show { transform: translateY(0); }
.pwa-banner .pwa-info { display: flex; align-items: center; gap: 12px; }
.pwa-banner .pwa-info svg { width: 28px; height: 28px; color: var(--primary); }
.pwa-banner .pwa-text { font-size: 0.85rem; }
.pwa-banner .pwa-text strong { display: block; font-size: 0.95rem; }
.pwa-banner .pwa-text span { color: var(--text-muted); }
.pwa-banner .pwa-actions { display: flex; gap: 8px; }
.pwa-banner .btn-install {
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 8px 20px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 500;
}
.pwa-banner .btn-dismiss {
  background: transparent;
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Tool Chain Menu Enhancement */
.chain-menu {
  position: absolute;
  bottom: 100%;
  right: 0;
  margin-bottom: 4px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  padding: 4px;
  min-width: 180px;
  z-index: 100;
}
.chain-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text);
  text-decoration: none;
  transition: background 0.15s;
}
.chain-item:hover { background: var(--primary-light); color: var(--primary); }
.chain-item svg { width: 14px; height: 14px; }

/* Usage Stats Bar */
.stats-bar {
  display: flex;
  gap: 16px;
  padding: 8px 0;
  font-size: 0.75rem;
  color: var(--text-muted);
}
.stats-bar .stat-item {
  display: flex;
  align-items: center;
  gap: 4px;
}
.stats-bar .stat-item svg { width: 12px; height: 12px; }

/* Keyboard Hint */
kbd {
  background: var(--border);
  color: var(--text);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-family: var(--font-body);
  border: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(0,0,0,0.05);
}

/* JSON Diff Colors */
.diff-added { background: rgba(34,197,94,0.12); color: #16A34A; }
.diff-removed { background: rgba(239,68,68,0.12); color: #DC2626; }
.diff-changed { background: rgba(251,191,36,0.12); color: #D97706; }
.diff-line { padding: 2px 8px; font-family: monospace; font-size: 0.85rem; border-radius: 4px; margin: 1px 0; }

/* Bar Chart (for stats tools) */
.bar-chart { display: flex; flex-direction: column; gap: 4px; }
.bar-chart .bar-row { display: flex; align-items: center; gap: 8px; font-size: 0.8rem; }
.bar-chart .bar-label { min-width: 80px; text-align: right; color: var(--text-muted); }
.bar-chart .bar-track { flex: 1; height: 20px; background: var(--border); border-radius: 4px; overflow: hidden; }
.bar-chart .bar-fill { height: 100%; background: var(--primary); border-radius: 4px; transition: width 0.3s; }
.bar-chart .bar-value { min-width: 40px; font-weight: 600; }

/* Tag Input */
.tag-input {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 6px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  min-height: 38px;
}
.tag-input .tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--primary-light);
  color: var(--primary);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.8rem;
}
.tag-input .tag .tag-remove { cursor: pointer; opacity: 0.6; }
.tag-input .tag .tag-remove:hover { opacity: 1; }
.tag-input input { border: none; outline: none; flex: 1; min-width: 80px; background: transparent; color: var(--text); }

/* Color Swatch Grid */
.swatch-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(60px, 1fr)); gap: 8px; }
.swatch-grid .swatch { aspect-ratio: 1; border-radius: 8px; cursor: pointer; position: relative; overflow: hidden; }
.swatch-grid .swatch .swatch-hex { position: absolute; bottom: 0; left: 0; right: 0; background: rgba(0,0,0,0.6); color: #fff; font-size: 0.65rem; text-align: center; padding: 2px; }

/* Toggle Switch */
.toggle-switch { position: relative; display: inline-block; width: 40px; height: 22px; }
.toggle-switch input { opacity: 0; width: 0; height: 0; }
.toggle-switch .slider { position: absolute; cursor: pointer; inset: 0; background: var(--border); border-radius: 22px; transition: 0.3s; }
.toggle-switch .slider:before { content: ''; position: absolute; height: 16px; width: 16px; left: 3px; bottom: 3px; background: #fff; border-radius: 50%; transition: 0.3s; }
.toggle-switch input:checked + .slider { background: var(--primary); }
.toggle-switch input:checked + .slider:before { transform: translateX(18px); }

/* Responsive Tuning */
@media (max-width: 640px) {
  .smart-grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); }
  .pwa-banner .pwa-text span { display: none; }
}