/* ==========================================================================
   Pashto Calculators (د پښتو حسابګرونه) - Core Design System & Stylesheet
   Direction: RTL-First | Pure CSS3 | Zero-Framework
   ========================================================================== */

/* --- Google Fonts Import (Noto Sans Arabic + Outfit for digits/code) --- */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+Arabic:wght@300;400;500;600;700;800;900&family=Outfit:wght@400;500;600;700&display=swap');

/* --- CSS Variables & Design Tokens --- */
:root {
  /* Color Palette - Light Mode */
  --font-primary: 'Noto Sans Arabic', system-ui, -apple-system, 'Segoe UI', Tahoma, Arial, sans-serif;
  --font-numbers: 'Outfit', 'Noto Sans Arabic', sans-serif;

  /* Theme Palette Definition:
     - #253C6D (Midnight Navy / Deep Royal Blue)
     - #30497D (Slate Navy)
     - #455B8A (Steel Blue / Muted Slate)
     - #F2842F (Vibrant Warm Orange)
  */
  --palette-navy-deep: #253C6D;
  --palette-navy-slate: #30497D;
  --palette-steel-blue: #455B8A;
  --palette-orange: #F2842F;
  --palette-orange-hover: #e0721c;

  /* Primary Brand: Deep Midnight Navy & Slate Navy */
  --primary-50: #f0f4fa;
  --primary-100: #dce5f5;
  --primary-200: #b9cbe7;
  --primary-300: #8ea8d6;
  --primary-400: #455B8A;
  --primary-500: #30497D;
  --primary-600: #253C6D;
  --primary-700: #1c2d52;
  --primary-800: #14213d;
  --primary-gradient: linear-gradient(135deg, #253C6D 0%, #30497D 55%, #455B8A 100%);
  --primary-glow: rgba(37, 60, 109, 0.22);

  /* Warm Accent: Vibrant Tangerine Orange */
  --accent-orange: #F2842F;
  --accent-orange-hover: #e0721c;
  --accent-orange-light: #fef4ec;
  --accent-orange-glow: rgba(242, 132, 47, 0.35);
  --accent-gradient: linear-gradient(135deg, #F2842F 0%, #fa9b4d 100%);

  /* Secondary & Supporting Accents */
  --accent-amber: #f59e0b;
  --accent-amber-light: #fef3c7;
  --accent-blue: #30497D;
  --accent-blue-light: #eff3fa;
  --accent-purple: #6366f1;
  --accent-rose: #e11d48;

  /* Semantic Feedback */
  --success: #10b981;
  --success-bg: #ecfdf5;
  --success-border: #a7f3d0;
  --warning: #F2842F;
  --warning-bg: #fff8f1;
  --warning-border: #fed7aa;
  --danger: #ef4444;
  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  --info: #30497D;
  --info-bg: #f0f4fa;
  --info-border: #b9cbe7;

  /* Backgrounds & Surfaces (Light) */
  --bg-page: #f5f7fb;
  --bg-page-subtle: #ebf0f8;
  --bg-card: #ffffff;
  --bg-card-hover: #fafcff;
  --bg-card-glass: rgba(255, 255, 255, 0.92);
  --bg-input: #f8fafc;
  --bg-input-focus: #ffffff;
  --bg-muted: #ebf0f8;

  /* Text & Hierarchies (Light) */
  --text-primary: #15223e;
  --text-secondary: #35476d;
  --text-muted: #5a6e94;
  --text-inverse: #ffffff;

  /* Borders & Dividers */
  --border-subtle: #dbe3f0;
  --border-strong: #b7c7df;
  --border-focus: #30497D;
  --border-color: #dbe3f0;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(21, 34, 62, 0.04);
  --shadow-sm: 0 2px 4px rgba(21, 34, 62, 0.06);
  --shadow-md: 0 6px 16px -2px rgba(21, 34, 62, 0.08), 0 2px 6px -1px rgba(21, 34, 62, 0.04);
  --shadow-lg: 0 16px 32px -4px rgba(21, 34, 62, 0.1), 0 6px 12px -2px rgba(21, 34, 62, 0.05);
  --shadow-glow: 0 0 24px rgba(37, 60, 109, 0.2);
  --shadow-orange: 0 4px 16px rgba(242, 132, 47, 0.35);

  /* Radius & Transitions */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  --transition-fast: 0.15s ease;
  --transition-base: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);

  /* Layout Constants */
  --container-max-width: 1200px;
  --header-height: 72px;
}

/* --- Dark Theme Variables --- */
[data-theme="dark"] {
  --bg-page: #131b2e;
  --bg-page-subtle: #19243d;
  --bg-card: #1e2d4d;
  --bg-card-hover: #26385d;
  --bg-card-glass: rgba(30, 45, 77, 0.88);
  --bg-input: #17233c;
  --bg-input-focus: #223356;
  --bg-muted: #253C6D;

  --text-primary: #ffffff;
  --text-secondary: #d3dcf0;
  --text-muted: #93a4c7;
  --text-inverse: #131b2e;

  --border-subtle: #2d416b;
  --border-strong: #455B8A;
  --border-focus: #F2842F;
  --border-color: #2d416b;

  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 6px 20px -2px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 36px -4px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 30px rgba(37, 60, 109, 0.4);

  --primary-50: #1b2a47;
  --primary-100: #253C6D;
  --primary-200: #30497D;
  --primary-500: #455B8A;
  --primary-600: #627cae;
  --primary-700: #88a2d4;

  --success-bg: rgba(16, 185, 129, 0.15);
  --success-border: rgba(16, 185, 129, 0.35);
  --warning-bg: rgba(242, 132, 47, 0.15);
  --warning-border: rgba(242, 132, 47, 0.35);
  --danger-bg: rgba(239, 68, 68, 0.15);
  --danger-border: rgba(239, 68, 68, 0.35);
  --info-bg: rgba(48, 73, 125, 0.25);
  --info-border: rgba(69, 91, 138, 0.4);
}

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

html {
  font-family: var(--font-primary);
  font-size: 16px;
  line-height: 1.65;
  direction: rtl;
  text-align: right;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-color: var(--bg-page);
  color: var(--text-primary);
  transition: background-color var(--transition-base), color var(--transition-base);
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background-color: var(--bg-page);
}

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

input, button, textarea, select {
  font: inherit;
  color: inherit;
  border: none;
  outline: none;
  background: none;
}

button {
  cursor: pointer;
  user-select: none;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

ul, ol {
  list-style: none;
}

/* --- Typography Helpers --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.35;
  color: var(--text-primary);
}

.num-western {
  font-family: var(--font-numbers);
  font-feature-settings: "tnum";
}

.num-pashto {
  font-family: var(--font-primary);
}

/* --- Container & Layout --- */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin-inline: auto;
  padding-inline: 1.25rem;
}

.page-wrapper {
  flex: 1;
  display: flex;
  flex-direction: column;
}

/* --- Header & Navigation --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: #253C6D;
  background: linear-gradient(90deg, #1d3058 0%, #253C6D 50%, #2e4575 100%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  height: var(--header-height);
  box-shadow: 0 4px 20px rgba(19, 27, 46, 0.22);
  transition: background-color var(--transition-base), border-color var(--transition-base);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 800;
  font-size: 1.3rem;
  color: #ffffff;
  text-decoration: none;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, #F2842F 0%, #e0721c 100%);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: 0 4px 14px rgba(242, 132, 47, 0.35);
  flex-shrink: 0;
}

.logo-icon svg {
  width: 22px;
  height: 22px;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.logo-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: #ffffff;
  background: none;
  -webkit-text-fill-color: #ffffff;
}

.logo-sub {
  font-size: 0.75rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.75);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  font-weight: 600;
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.88);
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-link:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.12);
}

.nav-link.active {
  color: #ffffff;
  background-color: #F2842F;
}

/* --- Navigation Mega Dropdown Menu --- */
.nav-dropdown-wrapper {
  position: relative;
  display: inline-block;
}

.nav-dropdown-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: transparent;
  border: none;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.88);
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.nav-dropdown-btn:hover,
.nav-dropdown-wrapper:hover .nav-dropdown-btn,
.nav-dropdown-wrapper.open .nav-dropdown-btn {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.12);
}

.nav-dropdown-btn .dropdown-chevron {
  transition: transform var(--transition-fast);
}

.nav-dropdown-wrapper:hover .dropdown-chevron,
.nav-dropdown-wrapper.open .dropdown-chevron {
  transform: rotate(180deg);
}

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 6px);
  right: -50px;
  width: 820px;
  max-width: 92vw;
  max-height: 82vh;
  overflow-y: auto;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 45px -10px rgba(15, 23, 42, 0.16), 0 8px 16px -4px rgba(15, 23, 42, 0.06);
  padding: 1.5rem;
  z-index: 1000;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
}

.nav-dropdown-wrapper:hover .nav-dropdown-menu,
.nav-dropdown-wrapper.open .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

[data-theme="dark"] .nav-dropdown-menu {
  box-shadow: 0 20px 45px -10px rgba(0, 0, 0, 0.5);
}

.dropdown-col-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--primary-600);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.75rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.dropdown-calc-list {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.dropdown-calc-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 0.6rem;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.88rem;
  font-weight: 500;
  text-decoration: none;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.dropdown-calc-link:hover {
  background-color: var(--primary-50);
  color: var(--primary-700);
}

[data-theme="dark"] .dropdown-calc-link:hover {
  background-color: var(--primary-50);
  color: var(--primary-500);
}

.dropdown-calc-icon {
  width: 18px;
  height: 18px;
  color: var(--primary-600);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.dropdown-calc-icon svg {
  width: 16px;
  height: 16px;
}

.nav-badge-count {
  font-size: 0.72rem;
  font-weight: 700;
  background: var(--accent-orange);
  color: #ffffff;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-full);
  margin-inline-start: 0.35rem;
  transition: all var(--transition-fast);
}

.nav-dropdown-btn:hover .nav-badge-count,
.nav-dropdown-wrapper.open .nav-badge-count {
  background: var(--accent-orange-hover);
  color: #ffffff;
}

/* --- Hero Quick Select Dropdown --- */
.hero-quick-dropdown-wrapper {
  margin-top: 1.25rem;
  width: 100%;
  max-width: 620px;
  margin-inline: auto;
  text-align: right;
}

.hero-dropdown-header-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.45rem;
  font-size: 0.85rem;
}

.hero-dropdown-badge {
  font-size: 0.72rem;
  font-weight: 700;
  background: var(--primary-50);
  color: var(--primary-700);
  border: 1px solid var(--primary-200);
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-full);
}

.hero-dropdown-title {
  font-weight: 700;
  color: var(--text-secondary);
  font-size: 0.88rem;
}

/* Section Header Quick Jump Dropdown */
.section-calc-dropdown-wrap {
  display: flex;
  align-items: center;
}

.section-quick-calc-select {
  border: 1.5px solid var(--border-subtle);
  background: var(--bg-card);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.88rem;
  font-weight: 600;
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  box-shadow: var(--shadow-xs);
  transition: all var(--transition-fast);
}

.section-quick-calc-select:hover,
.section-quick-calc-select:focus {
  border-color: var(--primary-500);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
  outline: none;
}

.hero-quick-dropdown-box {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--bg-card);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.5rem 0.9rem;
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.hero-quick-dropdown-box:focus-within {
  border-color: var(--primary-500);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
}

.hero-quick-icon {
  width: 22px;
  height: 22px;
  color: var(--primary-600);
  flex-shrink: 0;
}

.hero-calc-select {
  flex: 1;
  border: none;
  background: transparent;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.98rem;
  font-weight: 600;
  cursor: pointer;
  outline: none;
  width: 100%;
}

.hero-calc-select optgroup {
  font-weight: 700;
  color: var(--text-muted);
  background: var(--bg-page-subtle);
}

.hero-calc-select option {
  font-weight: 500;
  color: var(--text-primary);
  background: var(--bg-card);
  padding: 0.4rem;
}

/* --- Category Filter Tabs (Homepage Directory) --- */
.category-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.75rem;
  justify-content: center;
}

.filter-tab-btn {
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: all var(--transition-fast);
}

.filter-tab-btn:hover {
  border-color: var(--primary-500);
  color: var(--primary-700);
}

.filter-tab-btn.active {
  background: var(--primary-600);
  color: #ffffff;
  border-color: var(--primary-600);
  box-shadow: 0 2px 8px var(--primary-glow);
}

[data-theme="dark"] .filter-tab-btn.active {
  background: var(--palette-orange);
  color: #ffffff;
  border-color: var(--palette-orange);
  box-shadow: 0 2px 10px var(--accent-orange-glow);
}

/* Clear, Clean Card Aesthetics */
.calc-card {
  border: 1px solid var(--border-subtle);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.calc-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary-200);
  box-shadow: 0 10px 24px -4px rgba(15, 23, 42, 0.08);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

/* Action Icon Buttons */
.btn-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background-color: var(--bg-muted);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
  transition: all var(--transition-fast);
}

.btn-icon:hover {
  color: var(--primary-600);
  border-color: var(--primary-500);
  transform: translateY(-1px);
}

.site-header .btn-icon {
  background-color: rgba(255, 255, 255, 0.1);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.site-header .btn-icon:hover {
  background-color: var(--palette-orange);
  border-color: var(--palette-orange);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(242, 132, 47, 0.35);
}

.btn-icon svg {
  width: 20px;
  height: 20px;
}

/* Digits Switcher Button */
.btn-digits {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius-md);
  background-color: var(--bg-muted);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid var(--border-subtle);
  transition: all var(--transition-fast);
}

.site-header .btn-digits {
  background-color: rgba(255, 255, 255, 0.1);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.site-header .btn-digits:hover {
  background-color: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.3);
  color: #ffffff;
}

.btn-digits:hover {
  color: var(--primary-600);
  border-color: var(--primary-500);
}

.btn-digits .badge-digit {
  font-family: var(--font-numbers);
  background: var(--palette-orange);
  color: #fff;
  padding: 1px 6px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
}

/* Mobile Hamburger */
.mobile-menu-toggle {
  display: none;
}

/* --- Hero Section --- */
.hero-section {
  position: relative;
  padding: 3.5rem 0 2.5rem;
  overflow: hidden;
  background: radial-gradient(circle at 50% -20%, rgba(37, 60, 109, 0.15) 0%, rgba(242, 132, 47, 0.06) 45%, transparent 70%);
}

.hero-content {
  text-align: center;
  max-width: 780px;
  margin-inline: auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  border-radius: var(--radius-full);
  background: var(--primary-50);
  color: var(--primary-700);
  font-size: 0.875rem;
  font-weight: 600;
  border: 1px solid var(--primary-200);
  margin-bottom: 1.25rem;
  animation: pulseSubtle 3s infinite;
}

[data-theme="dark"] .hero-badge {
  background: rgba(48, 73, 125, 0.25);
  color: #ffffff;
  border-color: var(--palette-steel-blue);
}

.hero-title {
  font-size: clamp(1.85rem, 4vw, 2.75rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.35;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.hero-title span {
  background: linear-gradient(135deg, #253C6D 0%, #30497D 50%, #F2842F 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

[data-theme="dark"] .hero-title span {
  background: linear-gradient(135deg, #ffffff 0%, #bdcfe9 50%, #F2842F 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 2rem;
}

/* --- Search Component --- */
.search-container {
  position: relative;
  max-width: 640px;
  margin-inline: auto;
  margin-bottom: 1.75rem;
}

.search-box {
  position: relative;
  display: flex;
  align-items: center;
  background: var(--bg-card);
  border: 2px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 0.5rem 1rem;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

.search-box:focus-within {
  border-color: var(--palette-navy-slate);
  box-shadow: 0 0 0 4px rgba(48, 73, 125, 0.15), 0 10px 25px -5px rgba(21, 34, 62, 0.1);
  transform: translateY(-1px);
}

[data-theme="dark"] .search-box:focus-within {
  border-color: var(--palette-orange);
  box-shadow: 0 0 0 4px var(--accent-orange-glow), 0 10px 25px -5px rgba(0, 0, 0, 0.3);
}

.search-icon {
  color: var(--text-muted);
  width: 24px;
  height: 24px;
  margin-inline-end: 0.75rem;
  flex-shrink: 0;
}

.search-input {
  width: 100%;
  font-size: 1.05rem;
  padding: 0.45rem 0;
  color: var(--text-primary);
  font-weight: 500;
}

.search-input::placeholder {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.search-clear-btn {
  display: none;
  color: var(--text-muted);
  padding: 0.25rem;
  border-radius: 50%;
  transition: color var(--transition-fast);
}

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

.search-clear-btn svg {
  width: 18px;
  height: 18px;
}

/* Live Search Results Dropdown */
.search-results-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  inset-inline: 0;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-height: 420px;
  overflow-y: auto;
  z-index: 50;
  display: none;
}

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

.search-result-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.25rem;
  border-bottom: 1px solid var(--border-subtle);
  transition: background-color var(--transition-fast);
  text-decoration: none;
}

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

.search-result-item:hover, .search-result-item.selected {
  background-color: var(--bg-muted);
}

.search-result-info {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.search-result-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--primary-50);
  color: var(--primary-600);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

[data-theme="dark"] .search-result-icon {
  background: var(--palette-navy-deep);
  color: #ffffff;
}

.search-result-text {
  text-align: right;
}

.search-result-title {
  font-weight: 700;
  font-size: 0.98rem;
  color: var(--text-primary);
}

.search-result-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.search-result-cat {
  font-size: 0.78rem;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  background: var(--bg-muted);
  color: var(--text-muted);
  font-weight: 600;
}

.search-empty {
  padding: 2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Quick Search Chips */
.quick-chips {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 1rem;
}

.quick-chips-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 600;
  margin-inline-end: 0.25rem;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 600;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.chip:hover {
  border-color: var(--primary-500);
  color: var(--primary-700);
  background: var(--primary-50);
  transform: translateY(-1px);
}

.chip.active {
  background: var(--primary-600);
  border-color: var(--primary-600);
  color: #ffffff;
  box-shadow: 0 2px 8px var(--primary-glow);
}

[data-theme="dark"] .chip:hover {
  color: #ffffff;
  background: var(--palette-navy-deep);
  border-color: var(--palette-steel-blue);
}

[data-theme="dark"] .chip.active {
  background: var(--palette-orange);
  border-color: var(--palette-orange);
  color: #ffffff;
  box-shadow: 0 2px 10px var(--accent-orange-glow);
}

/* --- Section Layouts --- */
.section {
  padding: 3rem 0;
}

.section-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 2rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.section-title-wrap {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.section-title {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.section-title svg {
  color: var(--primary-600);
  width: 26px;
  height: 26px;
}

.section-subtitle {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.section-link {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--primary-600);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: gap var(--transition-fast);
}

.section-link:hover {
  gap: 0.6rem;
}

/* --- Cards Grid & Calculator Card --- */
.calc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 1.25rem;
}

.calc-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.35rem;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-xs);
  transition: all var(--transition-base);
  text-decoration: none;
  overflow: hidden;
}

.calc-card::before {
  content: '';
  position: absolute;
  top: 0;
  inset-inline: 0;
  height: 3px;
  background: linear-gradient(90deg, #253C6D, #F2842F);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.calc-card:hover {
  border-color: var(--primary-200);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

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

[data-theme="dark"] .calc-card:hover {
  border-color: var(--palette-steel-blue);
}

.calc-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.calc-card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--primary-50);
  color: var(--primary-600);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-fast), background-color var(--transition-fast), color var(--transition-fast);
}

.calc-card:hover .calc-card-icon {
  transform: scale(1.05);
  background: var(--primary-600);
  color: #ffffff;
}

[data-theme="dark"] .calc-card-icon {
  background: var(--palette-navy-deep);
  color: #ffffff;
}

[data-theme="dark"] .calc-card:hover .calc-card-icon {
  background: var(--palette-orange);
  color: #ffffff;
}

.calc-card-icon svg {
  width: 26px;
  height: 26px;
}

.btn-favorite-card {
  color: var(--text-muted);
  padding: 0.4rem;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), transform var(--transition-fast);
}

.btn-favorite-card:hover, .btn-favorite-card.active {
  color: var(--palette-orange);
  transform: scale(1.1);
}

.btn-favorite-card svg {
  width: 20px;
  height: 20px;
}

.calc-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.calc-card-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 1.25rem;
  flex: 1;
}

.calc-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.85rem;
  border-top: 1px solid var(--border-subtle);
}

.calc-card-category {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
}

.calc-card-arrow {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--primary-600);
}

/* --- Category Cards Grid --- */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 1.1rem;
}

.category-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: all var(--transition-base);
  text-decoration: none;
}

.category-card:hover {
  border-color: var(--primary-500);
  background-color: var(--bg-card-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.category-card-icon {
  width: 46px;
  height: 46px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.category-card-icon svg {
  width: 24px;
  height: 24px;
}

.cat-finance { background: rgba(37, 60, 109, 0.12); color: #253C6D; }
.cat-health  { background: rgba(225, 29, 72, 0.12); color: #e11d48; }
.cat-time    { background: rgba(48, 73, 125, 0.12); color: #30497D; }
.cat-math    { background: rgba(69, 91, 138, 0.15); color: #455B8A; }
.cat-units   { background: rgba(242, 132, 47, 0.15); color: #d0691b; }
.cat-construct { background: rgba(242, 132, 47, 0.12); color: #e0711e; }
.cat-travel  { background: rgba(48, 73, 125, 0.15); color: #253C6D; }
.cat-edu     { background: rgba(69, 91, 138, 0.12); color: #30497D; }

[data-theme="dark"] .cat-finance { background: rgba(37, 60, 109, 0.4); color: #ffffff; }
[data-theme="dark"] .cat-health  { background: rgba(225, 29, 72, 0.25); color: #fda4af; }
[data-theme="dark"] .cat-time    { background: rgba(48, 73, 125, 0.4); color: #ffffff; }
[data-theme="dark"] .cat-math    { background: rgba(69, 91, 138, 0.35); color: #ffffff; }
[data-theme="dark"] .cat-units   { background: rgba(242, 132, 47, 0.22); color: #F2842F; }
[data-theme="dark"] .cat-construct { background: rgba(242, 132, 47, 0.22); color: #F2842F; }
[data-theme="dark"] .cat-travel  { background: rgba(48, 73, 125, 0.4); color: #ffffff; }
[data-theme="dark"] .cat-edu     { background: rgba(69, 91, 138, 0.35); color: #ffffff; }

.category-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
}

.category-card-count {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* --- Features / Value Proposition Grid --- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.feature-box {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  text-align: right;
  transition: all var(--transition-base);
}

.feature-box:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
  border-color: var(--border-strong);
}

.feature-icon-wrap {
  width: 50px;
  height: 50px;
  border-radius: var(--radius-md);
  background: var(--primary-50);
  color: var(--primary-600);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
}

[data-theme="dark"] .feature-icon-wrap {
  background: var(--palette-navy-deep);
  color: #ffffff;
}

.feature-icon-wrap svg {
  width: 26px;
  height: 26px;
}

.feature-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
}

.feature-text {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* --- FAQ Accordion --- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 860px;
  margin-inline: auto;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--transition-fast);
}

.faq-question {
  width: 100%;
  padding: 1.15rem 1.35rem;
  text-align: right;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  transition: background-color var(--transition-fast);
}

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

.faq-chevron {
  color: var(--text-muted);
  transition: transform var(--transition-base);
  flex-shrink: 0;
}

.faq-item.open .faq-chevron {
  transform: rotate(180deg);
  color: var(--primary-600);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-smooth);
  padding: 0 1.35rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding-bottom: 1.25rem;
}

/* --- Breadcrumbs --- */
.breadcrumb-nav {
  padding: 1rem 0;
}

.breadcrumb-list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.breadcrumb-item a {
  color: var(--text-secondary);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.breadcrumb-item a:hover {
  color: var(--primary-600);
}

.breadcrumb-separator {
  color: var(--border-strong);
  font-size: 0.75rem;
}

.breadcrumb-item.current {
  color: var(--primary-600);
  font-weight: 700;
}

/* --- Calculator Engine & Page Layout --- */
.calc-page-layout {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 2rem;
  margin-bottom: 3rem;
  align-items: start;
}

.calc-main-area {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.calc-sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Calculator Card (Main interactive component) */
.calc-workbench-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  position: relative;
}

.calc-header-box {
  margin-bottom: 1.75rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-subtle);
}

.calc-page-title {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 800;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.calc-page-subtitle {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Form Controls & Inputs */
.calc-form-group {
  margin-bottom: 1.5rem;
  min-width: 0;
}

.calc-form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}

.calc-form-grid > * {
  min-width: 0;
}

.calc-form-grid .calc-form-group {
  margin-bottom: 0;
}

.calc-label {
  display: block;
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.calc-label-hint {
  font-weight: 400;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-inline-start: 0.35rem;
}

.calc-input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
  background: var(--bg-input);
  border: 2px solid var(--border-subtle);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  width: 100%;
  min-width: 0;
  max-width: 100%;
}

.calc-input-wrapper:focus-within {
  border-color: var(--primary-500);
  background: var(--bg-input-focus);
  box-shadow: 0 0 0 4px var(--primary-glow);
}

.calc-input-wrapper.error {
  border-color: var(--danger);
  background: var(--danger-bg);
}

.calc-input {
  width: 100%;
  padding: 0.85rem 1rem;
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  background: transparent;
}

.calc-input::placeholder {
  color: var(--text-muted);
  font-weight: 400;
  font-size: 0.95rem;
}

.calc-unit-addon {
  padding: 0.85rem 1rem;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-muted);
  background: var(--bg-muted);
  border-inline-start: 1px solid var(--border-subtle);
  user-select: none;
}

.calc-select {
  padding: 0.85rem 1rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  background: var(--bg-muted);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  cursor: pointer;
  max-width: 100%;
  min-width: 0;
}

.calc-select option {
  color: var(--text-primary);
  background: var(--bg-card);
}

/* When select is an addon inside input-wrapper alongside an input */
.calc-input-wrapper .calc-select {
  border: none;
  border-inline-start: 1px solid var(--border-subtle);
  border-radius: 0;
  background: var(--bg-muted);
}

/* When select is standalone inside input-wrapper */
.calc-input-wrapper > .calc-select:only-child,
.calc-select.calc-select-full {
  flex: 1 1 100%;
  width: 100%;
  min-width: 0;
  max-width: 100%;
  background: transparent;
  border: none;
  border-inline-start: none;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.calc-field-error {
  font-size: 0.84rem;
  color: var(--danger);
  margin-top: 0.4rem;
  display: none;
  font-weight: 600;
}

.calc-input-wrapper.error + .calc-field-error {
  display: block;
}

/* Tabs & Switchers */
.calc-tabs {
  display: flex;
  gap: 0.5rem;
  background: var(--bg-muted);
  padding: 0.35rem;
  border-radius: var(--radius-md);
  margin-bottom: 1.75rem;
}

.calc-tab-btn {
  flex: 1;
  padding: 0.6rem 1rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.92rem;
  color: var(--text-secondary);
  text-align: center;
  transition: all var(--transition-fast);
}

.calc-tab-btn:hover {
  color: var(--text-primary);
}

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

[data-theme="dark"] .calc-tab-btn.active {
  color: #ffffff;
  background: var(--palette-navy-deep);
  border: 1px solid var(--palette-steel-blue);
}

/* Button Row */
.calc-actions-row {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-top: 2rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: linear-gradient(135deg, #F2842F 0%, #e0721c 100%);
  color: #ffffff;
  font-weight: 700;
  font-size: 1.05rem;
  padding: 0.85rem 2rem;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 16px rgba(242, 132, 47, 0.35), var(--shadow-sm);
  transition: all var(--transition-fast);
  flex: 2;
  cursor: pointer;
}

.btn-primary:hover {
  background: linear-gradient(135deg, #f7903f 0%, #e0721c 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 22px rgba(242, 132, 47, 0.45), var(--shadow-md);
}

.btn-primary:active {
  transform: translateY(1px);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: var(--bg-muted);
  color: var(--text-secondary);
  font-weight: 700;
  font-size: 1rem;
  padding: 0.85rem 1.35rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  transition: all var(--transition-fast);
  flex: 1;
  cursor: pointer;
}

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

/* --- Result Card Component --- */
.calc-result-card {
  background: linear-gradient(145deg, var(--bg-card), var(--bg-page-subtle));
  border: 2px solid var(--primary-500);
  border-radius: var(--radius-xl);
  padding: 1.75rem;
  box-shadow: var(--shadow-md);
  display: none;
  animation: slideUp 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="dark"] .calc-result-card {
  border: 2px solid var(--palette-steel-blue);
  background: linear-gradient(145deg, #223356, #17233c);
}

.calc-result-card.active {
  display: block;
}

.calc-result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px dashed var(--border-strong);
}

.calc-result-badge {
  font-size: 0.85rem;
  font-weight: 800;
  color: #ffffff;
  background: #253C6D;
  padding: 0.3rem 0.85rem;
  border-radius: var(--radius-full);
}

[data-theme="dark"] .calc-result-badge {
  color: #ffffff;
  background: #F2842F;
}

.calc-result-actions {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.calc-main-result-value,
.calc-highlight-value {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 900;
  color: #F2842F;
  line-height: 1.15;
  margin-bottom: 0.5rem;
  font-family: var(--font-numbers);
}

[data-theme="dark"] .calc-main-result-value,
[data-theme="dark"] .calc-highlight-value {
  color: #F2842F;
  text-shadow: 0 0 25px rgba(242, 132, 47, 0.3);
}

.calc-highlight-label {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
}

[data-theme="dark"] .calc-highlight-label {
  color: #ffffff;
}

.calc-highlight-sub {
  font-size: 0.92rem;
  color: var(--text-muted);
}

[data-theme="dark"] .calc-highlight-sub {
  color: var(--text-secondary);
}

/* Status Badge */
.calc-status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.95rem;
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.calc-status-badge.badge-success {
  background: var(--success-bg);
  color: var(--success);
  border: 1px solid var(--success-border);
}

.calc-status-badge.badge-warning {
  background: var(--warning-bg);
  color: var(--warning);
  border: 1px solid var(--warning-border);
}

.calc-result-explanation {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.calc-breakdown-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.85rem;
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-subtle);
}

.calc-breakdown-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.85rem;
  text-align: right;
}

.calc-breakdown-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.calc-breakdown-val {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-primary);
  font-family: var(--font-numbers);
}

/* Copy Toast */
.copy-feedback-toast {
  position: fixed;
  bottom: 2rem;
  inset-inline-start: 50%;
  transform: translateX(50%) translateY(100px);
  background: var(--text-primary);
  color: var(--text-inverse);
  padding: 0.65rem 1.5rem;
  border-radius: var(--radius-full);
  font-size: 0.95rem;
  font-weight: 700;
  box-shadow: var(--shadow-lg);
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

/* --- Explanatory & Content Sections --- */
.content-article {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: var(--shadow-xs);
}

.content-article h2 {
  font-size: 1.45rem;
  font-weight: 800;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--text-primary);
}

.content-article p {
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 1.25rem;
  font-size: 0.98rem;
}

.formula-box {
  background: var(--bg-muted);
  border-inline-start: 4px solid var(--primary-600);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.25rem 0;
  font-family: var(--font-numbers);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  direction: ltr;
  text-align: left;
}

.formula-box.rtl-text {
  direction: rtl;
  text-align: right;
  font-family: var(--font-primary);
}

.example-card {
  background: var(--bg-page-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin: 1.25rem 0;
}

.example-card h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--primary-600);
}

/* Sidebar Elements */
.sidebar-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.35rem;
}

.sidebar-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.related-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.related-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.5rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  color: var(--text-secondary);
  font-size: 0.92rem;
  font-weight: 600;
}

.related-item:hover {
  background: var(--bg-muted);
  color: var(--primary-600);
  transform: translateX(-3px);
}

.related-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--primary-50);
  color: var(--palette-navy-deep);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

[data-theme="dark"] .related-icon {
  background: rgba(69, 91, 138, 0.25);
  color: var(--palette-orange);
}

.related-icon svg {
  width: 18px;
  height: 18px;
}

/* Disclaimer Box */
.disclaimer-box {
  background: var(--warning-bg);
  border: 1px solid var(--warning-border);
  border-radius: var(--radius-md);
  padding: 1rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
  display: flex;
  gap: 0.75rem;
}

.disclaimer-icon {
  color: var(--warning);
  flex-shrink: 0;
  width: 22px;
  height: 22px;
}

/* --- Footer --- */
.site-footer {
  background: linear-gradient(180deg, #1c2a47 0%, #131d33 100%);
  border-top: 1px solid rgba(69, 91, 138, 0.35);
  color: #c8d4ea;
  padding: 4rem 0 2rem;
  margin-top: auto;
  transition: background var(--transition-base);
}

[data-theme="dark"] .site-footer {
  background: linear-gradient(180deg, #121929 0%, #0a0f1a 100%);
  border-top: 1px solid rgba(69, 91, 138, 0.25);
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.footer-about {
  font-size: 0.92rem;
  color: #b7c7df;
  line-height: 1.7;
}

.footer-col-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  color: #ffffff;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-link {
  font-size: 0.9rem;
  color: #b7c7df;
  transition: all var(--transition-fast);
}

.footer-link:hover {
  color: var(--palette-orange);
  transform: translateX(-3px);
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(69, 91, 138, 0.25);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  color: #8fa3c7;
}

/* --- Keyframe Animations --- */
@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulseSubtle {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.02);
  }
}