/* ============================================
   ONEYFY - Main Stylesheet
   ============================================ */

/* Google Fonts — must be first rule before any CSS declarations */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* 1. CSS Reset & Normalize */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
}

input, button, textarea, select {
  font: inherit;
}

p, h1, h2, h3, h4, h5, h6 {
  overflow-wrap: break-word;
}

ul, ol {
  list-style: none;
}

a {
  text-decoration: none;
  color: inherit;
}

/* 2. CSS Custom Properties */
:root {
  /* Light mode colors */
  --bg-primary: #f8fafc;
  --bg-secondary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-input: #ffffff;
  --color-primary: #6366f1;
  --color-primary-hover: #4f46e5;
  --color-primary-light: #e0e7ff;
  --color-secondary: #8b5cf6;
  --color-secondary-light: #ede9fe;
  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.08), 0 4px 6px rgba(0,0,0,0.04);
  --shadow-hover: 0 20px 25px rgba(0,0,0,0.1), 0 8px 10px rgba(0,0,0,0.06);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --transition: 0.2s ease;
  --transition-slow: 0.3s ease;

  /* Gradients */
  --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --gradient-card: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;

  /* Aliases — short names used across tool pages */
  --card-bg: var(--bg-card);
  --bg: var(--bg-input);
  --border: var(--border-color);
  --primary: var(--color-primary);
}

/* Dark mode */
html.dark {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --bg-input: #273349;
  --color-primary: #818cf8;
  --color-primary-hover: #6366f1;
  --color-primary-light: #1e1b4b;
  --color-secondary: #a78bfa;
  --color-secondary-light: #2e1065;
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --border-color: #334155;
  --border-hover: #475569;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3), 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.3), 0 2px 4px rgba(0,0,0,0.2);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.3), 0 4px 6px rgba(0,0,0,0.2);
  --shadow-hover: 0 20px 25px rgba(0,0,0,0.4), 0 8px 10px rgba(0,0,0,0.3);
  --gradient-card: linear-gradient(135deg, #1e293b 0%, #273349 100%);
}

/* 3. Typography System */
body {
  font-family: var(--font-family);
  font-size: 1rem;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-slow), color var(--transition-slow);
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
}

h1 { font-size: clamp(1.75rem, 4vw, 2.75rem); }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); }
h3 { font-size: clamp(1.1rem, 2vw, 1.4rem); }
h4 { font-size: 1.1rem; }

p { color: var(--text-secondary); }

.text-primary { color: var(--color-primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }
.text-center { text-align: center; }
.font-mono { font-family: var(--font-mono); }

/* 4. Layout Utilities */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.container-sm {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }
.gap-4 { gap: 2rem; }

.grid { display: grid; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.w-full { width: 100%; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* 5. Header / Nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: background-color var(--transition-slow), border-color var(--transition-slow);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 1.5rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-primary);
  transition: opacity var(--transition);
  flex-shrink: 0;
}

.logo:hover { opacity: 0.85; }

.logo-icon {
  font-size: 1.5rem;
  filter: drop-shadow(0 0 8px rgba(99, 102, 241, 0.5));
}

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

.main-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.main-nav a {
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all var(--transition);
}

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

.dark-mode-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: var(--bg-secondary);
  cursor: pointer;
  font-size: 1.1rem;
  transition: all var(--transition);
  flex-shrink: 0;
}

.dark-mode-toggle:hover {
  background: var(--color-primary-light);
  border-color: var(--color-primary);
  transform: scale(1.05);
}

html:not(.dark) .moon-icon,
html.dark .sun-icon {
  display: none;
}

/* 6. Hero Section */
.hero {
  background: var(--gradient-hero);
  padding: 5rem 0 4rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
}

.hero .container { position: relative; z-index: 1; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(255,255,255,0.15);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.25);
  border-radius: 100px;
  padding: 0.35rem 1rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: rgba(255,255,255,0.95);
  margin-bottom: 1.5rem;
  letter-spacing: 0.02em;
}

.hero h1 {
  color: #ffffff;
  margin-bottom: 1.25rem;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
  text-shadow: 0 2px 20px rgba(0,0,0,0.15);
}

.hero-subtitle {
  font-size: 1.15rem;
  color: rgba(255,255,255,0.85);
  max-width: 520px;
  margin: 0 auto 2.5rem;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 2.5rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

.hero-stat {
  text-align: center;
}

.hero-stat .stat-number {
  font-size: 1.6rem;
  font-weight: 800;
  color: #ffffff;
  display: block;
}

.hero-stat .stat-label {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.75);
  font-weight: 500;
}

/* 7. Search Bar */
.search-wrapper {
  position: relative;
  max-width: 560px;
  margin: 0 auto;
}

.search-wrapper .search-icon {
  position: absolute;
  left: 1.1rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.1rem;
  pointer-events: none;
  opacity: 0.6;
}

.search-input {
  width: 100%;
  padding: 0.9rem 1rem 0.9rem 3rem;
  font-size: 1rem;
  border-radius: var(--radius-xl);
  border: 2px solid rgba(255,255,255,0.3);
  background: rgba(255,255,255,0.15);
  color: #ffffff;
  backdrop-filter: blur(10px);
  transition: all var(--transition);
  outline: none;
}

.search-input::placeholder { color: rgba(255,255,255,0.65); }

.search-input:focus {
  border-color: rgba(255,255,255,0.7);
  background: rgba(255,255,255,0.25);
  box-shadow: 0 0 0 4px rgba(255,255,255,0.1);
}

/* Tools section search (non-hero) */
.tools-search .search-input {
  background: var(--bg-input);
  color: var(--text-primary);
  border-color: var(--border-color);
}

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

.tools-search .search-input:focus {
  border-color: var(--color-primary);
  background: var(--bg-input);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

/* 8. Category Filter Buttons */
.category-filters {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  justify-content: center;
  padding: 1.75rem 0 1.25rem;
}

.filter-btn {
  padding: 0.45rem 1.1rem;
  border-radius: 100px;
  border: 1.5px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

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

.filter-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(99, 102, 241, 0.35);
}

/* 9. Tool Cards */
.tools-section {
  padding: 3rem 0 5rem;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.section-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.tool-count {
  font-size: 0.85rem;
  color: var(--text-muted);
  background: var(--bg-secondary);
  padding: 0.25rem 0.75rem;
  border-radius: 100px;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}

.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  cursor: pointer;
  transition: all var(--transition-slow);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  text-decoration: none;
  color: inherit;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-primary);
  opacity: 0;
  transition: opacity var(--transition);
}

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

.tool-card:hover::before { opacity: 1; }

.tool-card-icon {
  font-size: 2.2rem;
  line-height: 1;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-light);
  border-radius: var(--radius-md);
  transition: transform var(--transition);
}

.tool-card:hover .tool-card-icon { transform: scale(1.1); }

.tool-card-content { flex: 1; }

.tool-card-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}

.tool-card-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.tool-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 0.25rem;
}

.tool-card-category {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-primary-hover);
  background: var(--color-primary-light);
  padding: 0.2rem 0.6rem;
  border-radius: 100px;
}

.tool-card-arrow {
  font-size: 1rem;
  color: var(--color-primary);
  opacity: 0;
  transform: translateX(-4px);
  transition: all var(--transition);
}

.tool-card:hover .tool-card-arrow {
  opacity: 1;
  transform: translateX(0);
}

.no-results {
  grid-column: 1/-1;
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-muted);
}

.no-results .no-results-icon { font-size: 3rem; margin-bottom: 1rem; }
.no-results h3 { color: var(--text-secondary); margin-bottom: 0.5rem; }

/* 10. Sidebar (Tools Directory) */
.tools-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 2rem;
  padding: 2.5rem 0 5rem;
  align-items: start;
}

.sidebar {
  position: sticky;
  top: 80px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.sidebar-header {
  padding: 1.1rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.sidebar-category {
  border-bottom: 1px solid var(--border-color);
}

.sidebar-category:last-child { border-bottom: none; }

.sidebar-category-toggle {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.25rem;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  transition: background var(--transition);
}

.sidebar-category-toggle:hover { background: var(--bg-secondary); }

.sidebar-category-toggle .chevron {
  transition: transform var(--transition);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.sidebar-category.open .chevron { transform: rotate(90deg); }

.sidebar-category-links {
  display: none;
  flex-direction: column;
  background: var(--bg-secondary);
}

.sidebar-category.open .sidebar-category-links { display: flex; }

.sidebar-link {
  padding: 0.6rem 1.25rem 0.6rem 2rem;
  font-size: 0.84rem;
  color: var(--text-secondary);
  transition: all var(--transition);
  border-left: 2px solid transparent;
}

.sidebar-link:hover {
  color: var(--color-primary);
  background: var(--color-primary-light);
  border-left-color: var(--color-primary);
}

.sidebar-link.active {
  color: var(--color-primary);
  border-left-color: var(--color-primary);
  font-weight: 500;
}

/* 11. Tool Page Layout */
.breadcrumb {
  padding: 1rem 0;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.breadcrumb a { color: var(--color-primary); }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb-sep { color: var(--border-color); }

.tool-page {
  padding: 2rem 0 5rem;
}

.tool-page-header {
  margin-bottom: 2rem;
}

.tool-page-icon {
  font-size: 2.75rem;
  margin-bottom: 0.75rem;
  display: block;
}

.tool-page-header h1 {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  margin-bottom: 0.5rem;
}

.tool-page-header p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 600px;
}

.tool-container {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.tool-form {
  padding: 2rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.45rem;
}

.form-group label .optional {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.8rem;
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}

input[type="text"],
input[type="number"],
input[type="date"],
input[type="time"],
input[type="email"],
select,
textarea {
  width: 100%;
  padding: 0.7rem 1rem;
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-input);
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: all var(--transition);
  outline: none;
  appearance: none;
  -webkit-appearance: none;
}

input[type="text"]:focus,
input[type="number"]:focus,
input[type="date"]:focus,
input[type="time"]:focus,
input[type="email"]:focus,
select:focus,
textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

input[type="text"]:hover,
input[type="number"]:hover,
input[type="date"]:hover,
input[type="time"]:hover,
input[type="email"]:hover,
select:hover,
textarea:hover {
  border-color: var(--border-hover);
}

select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2364748b' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.85rem center;
  padding-right: 2.5rem;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--color-primary);
  height: 6px;
  cursor: pointer;
}

.input-group {
  display: flex;
  gap: 0;
}

.input-group input {
  border-radius: var(--radius-md) 0 0 var(--radius-md);
  border-right: none;
}

.input-group select {
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  min-width: 100px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--text-secondary);
  padding: 0.25rem 0;
}

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

.radio-group {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.radio-label input[type="radio"] {
  accent-color: var(--color-primary);
}

.form-actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.75rem;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.5rem;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-primary);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
  box-shadow: 0 4px 16px rgba(99, 102, 241, 0.5);
  transform: translateY(-1px);
  opacity: 0.92;
}

.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1.5px solid var(--border-color);
}

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

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 1.5px solid var(--color-primary);
}

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

.btn-sm {
  padding: 0.45rem 0.9rem;
  font-size: 0.82rem;
}

.btn-lg {
  padding: 0.9rem 2.2rem;
  font-size: 1.05rem;
}

.btn-icon {
  padding: 0.5rem;
  background: var(--bg-secondary);
  border: 1.5px solid var(--border-color);
  color: var(--text-secondary);
  border-radius: var(--radius-md);
}

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

/* Results Panel */
.results-panel {
  display: none;
  border-top: 1px solid var(--border-color);
  padding: 2rem;
  background: var(--bg-secondary);
}

.results-panel.visible { display: block; }

.results-panel h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 1.25rem;
}

.result-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 1rem;
}

.result-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.1rem 1.25rem;
}

.result-label {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

.result-value {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.2;
}

.result-value.highlight {
  color: var(--color-primary);
  font-size: 1.6rem;
}

.result-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

.result-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.9rem;
}

.result-row:last-child { border-bottom: none; }

.result-row .label { color: var(--text-secondary); }

.result-row .value {
  font-weight: 600;
  color: var(--text-primary);
  font-family: var(--font-mono);
}

.alert {
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
  margin-bottom: 1rem;
}

.alert-error {
  background: #fef2f2;
  border: 1px solid #fecaca;
  color: #dc2626;
}

html.dark .alert-error {
  background: #450a0a;
  border-color: #991b1b;
  color: #fca5a5;
}

.alert-success {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
  color: #16a34a;
}

html.dark .alert-success {
  background: #052e16;
  border-color: #166534;
  color: #86efac;
}

.alert-info {
  background: var(--color-primary-light);
  border: 1px solid rgba(99, 102, 241, 0.3);
  color: var(--color-primary-hover);
}

html.dark .alert-info {
  color: var(--color-primary);
}

/* Table rows for calculators */
.dynamic-rows {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.dynamic-row {
  display: grid;
  gap: 0.75rem;
  align-items: end;
}

.dynamic-row .remove-row {
  padding: 0.7rem 0.85rem;
  background: var(--bg-secondary);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--text-muted);
  font-size: 1rem;
  transition: all var(--transition);
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.dynamic-row .remove-row:hover {
  background: #fef2f2;
  color: #dc2626;
  border-color: #fecaca;
}

/* Strength indicator */
.strength-bar {
  height: 6px;
  border-radius: 100px;
  background: var(--border-color);
  overflow: hidden;
  margin-top: 0.5rem;
}

.strength-fill {
  height: 100%;
  border-radius: 100px;
  transition: width 0.4s ease, background 0.4s ease;
}

.strength-label {
  font-size: 0.8rem;
  font-weight: 600;
  margin-top: 0.35rem;
}

/* BMI scale */
.bmi-scale {
  position: relative;
  height: 24px;
  border-radius: 100px;
  background: linear-gradient(to right, #3b82f6 0%, #22c55e 25%, #f59e0b 50%, #ef4444 75%, #dc2626 100%);
  margin: 1rem 0 0.5rem;
}

.bmi-indicator {
  position: absolute;
  top: -6px;
  transform: translateX(-50%);
  width: 12px;
  height: 36px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: left 0.5s ease;
}

/* Pace table */
.splits-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.splits-table th {
  padding: 0.6rem 0.85rem;
  text-align: left;
  background: var(--bg-primary);
  color: var(--text-muted);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.splits-table td {
  padding: 0.65rem 0.85rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-primary);
}

.splits-table tr:last-child td { border-bottom: none; }
.splits-table tr:hover td { background: var(--bg-secondary); }

/* Timeline (pregnancy) */
.milestone-timeline {
  position: relative;
  padding-left: 1.5rem;
}

.milestone-timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border-color);
}

.milestone-item {
  position: relative;
  padding: 0.6rem 0 0.6rem 1.25rem;
}

.milestone-item::before {
  content: '';
  position: absolute;
  left: -0.45rem;
  top: 50%;
  transform: translateY(-50%);
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 2px solid var(--bg-card);
}

.milestone-item.past::before { background: var(--text-muted); }
.milestone-item.current::before {
  background: var(--color-primary);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.2);
}

.milestone-week {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.milestone-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* Password display */
.password-display {
  background: var(--bg-primary);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--text-primary);
  word-break: break-all;
  line-height: 1.6;
  min-height: 60px;
  display: flex;
  align-items: center;
  position: relative;
}

/* Conversion result */
.conversion-result {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-primary);
  text-align: center;
  padding: 1.5rem;
}

.conversion-formula {
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* Toggle switch */
.toggle-switch {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
}

.toggle-switch input {
  display: none;
}

.toggle-track {
  width: 44px;
  height: 24px;
  border-radius: 100px;
  background: var(--border-color);
  position: relative;
  transition: background var(--transition);
}

.toggle-switch input:checked + .toggle-track { background: var(--color-primary); }

.toggle-thumb {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: white;
  transition: transform var(--transition);
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.toggle-switch input:checked + .toggle-track .toggle-thumb {
  transform: translateX(20px);
}

/* Mode tabs */
.mode-tabs {
  display: flex;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: 0.25rem;
  gap: 0.25rem;
  margin-bottom: 1.5rem;
}

.mode-tab {
  flex: 1;
  padding: 0.55rem 1rem;
  border-radius: calc(var(--radius-md) - 2px);
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  text-align: center;
}

.mode-tab.active {
  background: var(--bg-card);
  color: var(--color-primary);
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}

/* 12. SEO Content Section */
.seo-section {
  padding: 4rem 0;
  border-top: 1px solid var(--border-color);
  margin-top: 3rem;
}

.seo-content {
  max-width: 820px;
  margin: 0 auto;
}

.seo-content h2 {
  font-size: 1.75rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--border-color);
}

.seo-content h3 {
  font-size: 1.2rem;
  margin: 2rem 0 0.85rem;
  color: var(--color-primary);
}

.seo-content p {
  margin-bottom: 1rem;
  line-height: 1.75;
}

.seo-content ol,
.seo-content ul {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}

.seo-content ol { list-style: decimal; }
.seo-content ul { list-style: disc; }

.seo-content li {
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
  line-height: 1.6;
  padding-left: 0.25rem;
}

.faq-list { margin-top: 1rem; }

.faq-item {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 0.75rem;
  overflow: hidden;
}

.faq-question {
  padding: 1rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--bg-card);
  transition: background var(--transition);
  user-select: none;
  border: none;
  width: 100%;
  text-align: left;
}

.faq-question:hover { background: var(--bg-secondary); }

.faq-question .faq-icon {
  font-size: 1.2rem;
  color: var(--color-primary);
  transition: transform var(--transition);
  flex-shrink: 0;
}

.faq-item.open .faq-icon { transform: rotate(45deg); }

.faq-answer {
  display: none;
  padding: 1rem 1.25rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  background: var(--bg-secondary);
  line-height: 1.7;
  border-top: 1px solid var(--border-color);
}

.faq-item.open .faq-answer { display: block; }

code {
  font-family: var(--font-mono);
  background: var(--bg-secondary);
  padding: 0.15em 0.5em;
  border-radius: var(--radius-sm);
  font-size: 0.875em;
  color: var(--color-primary);
}

/* 13. Footer */
.site-footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border-color);
  padding: 3.5rem 0 1.5rem;
  transition: background var(--transition-slow);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

.footer-brand .logo {
  font-size: 1.3rem;
  margin-bottom: 0.75rem;
  display: inline-flex;
}

.footer-brand p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
  max-width: 280px;
}

.footer-links h4 {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.85rem;
}

.footer-links a {
  display: block;
  font-size: 0.875rem;
  color: var(--text-secondary);
  padding: 0.2rem 0;
  transition: color var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 1.5rem;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* 14. Responsive Breakpoints */
@media (max-width: 1024px) {
  .tools-layout {
    grid-template-columns: 220px 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr 1fr;
  }
  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 640px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .footer-brand {
    grid-column: 1 / -1;
  }
}

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

  .sidebar {
    position: static;
    display: none;
  }

  .sidebar.mobile-open {
    display: block;
  }

  .tools-grid {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .hero {
    padding: 3.5rem 0 3rem;
  }

  .hero-stats {
    gap: 1.5rem;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .result-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .main-nav {
    display: none;
  }

  .site-header .container {
    gap: 0.75rem;
  }
}

@media (max-width: 480px) {
  .tools-grid {
    grid-template-columns: 1fr;
  }

  .category-filters {
    gap: 0.4rem;
  }

  .filter-btn {
    padding: 0.4rem 0.85rem;
    font-size: 0.8rem;
  }

  .result-grid {
    grid-template-columns: 1fr;
  }

  .tool-form {
    padding: 1.25rem;
  }

  .results-panel {
    padding: 1.25rem;
  }
}

/* 15. Smooth transitions */
* { transition-property: none; }

html {
  --base-transition: color, background-color, border-color, box-shadow, opacity, transform;
}

a, button, .tool-card, .filter-btn, .sidebar-link, .faq-question {
  transition: color var(--transition), background-color var(--transition), border-color var(--transition), box-shadow var(--transition), opacity var(--transition), transform var(--transition);
}

input, select, textarea {
  transition: border-color var(--transition), box-shadow var(--transition), background-color var(--transition);
}

/* Loading animation */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.tool-card {
  animation: fadeInUp 0.3s ease both;
}

.tool-card:nth-child(1) { animation-delay: 0.02s; }
.tool-card:nth-child(2) { animation-delay: 0.04s; }
.tool-card:nth-child(3) { animation-delay: 0.06s; }
.tool-card:nth-child(4) { animation-delay: 0.08s; }
.tool-card:nth-child(5) { animation-delay: 0.1s; }
.tool-card:nth-child(6) { animation-delay: 0.12s; }

/* Utility: hidden */
.hidden { display: none !important; }

/* Progress bar */
.progress-bar {
  height: 8px;
  background: var(--border-color);
  border-radius: 100px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: 100px;
  transition: width 0.5s ease;
}

/* Copy feedback */
.copy-feedback {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: #1e293b;
  color: #f1f5f9;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  animation: fadeInUp 0.25s ease;
}

/* Mobile sidebar toggle */
.sidebar-toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: var(--bg-card);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  margin-bottom: 1rem;
}

@media (max-width: 768px) {
  .sidebar-toggle { display: flex; }
}