/* ============================================================
   SIGMA ACADEMY — Design System
   Version 1.0 | Deep Navy + White + Academic Blue
   ============================================================ */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Cairo:wght@300;400;500;600;700;800;900&family=Plus+Jakarta+Sans:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;1,400&display=swap');

/* ============================================================
   1. CSS Custom Properties (Design Tokens)
   ============================================================ */
:root {
  /* Brand Colors */
  --sigma-navy:       #0d1f4e;   /* Primary — Deep Navy (from logo) */
  --sigma-navy-dark:  #080f28;   /* Darker Navy */
  --sigma-navy-light: #162660;   /* Lighter Navy */
  --sigma-blue:       #1a3a7c;   /* Academic Blue */
  --sigma-royal:      #2461c5;   /* Royal Blue Accent */
  --sigma-ice:        #eef4ff;   /* Ice Blue Background */
  --sigma-light:      #f8faff;   /* Very Light Blue-White */

  /* Neutrals */
  --sigma-white:      #ffffff;
  --sigma-gray-50:    #f9fafb;
  --sigma-gray-100:   #f3f4f8;
  --sigma-gray-200:   #e5e7ef;
  --sigma-gray-300:   #d1d5e0;
  --sigma-gray-400:   #9aa3b8;
  --sigma-gray-500:   #6b7494;
  --sigma-gray-600:   #4b526e;
  --sigma-gray-700:   #374151;
  --sigma-gray-800:   #1f2637;
  --sigma-gray-900:   #111827;

  /* Text */
  --text-primary:    var(--sigma-navy);
  --text-secondary:  var(--sigma-gray-500);
  --text-muted:      var(--sigma-gray-400);
  --text-on-dark:    #ffffff;
  --text-on-dark-2:  rgba(255,255,255,0.8);
  --text-on-dark-3:  rgba(255,255,255,0.55);

  /* Backgrounds */
  --bg-page:        var(--sigma-white);
  --bg-section:     var(--sigma-gray-50);
  --bg-ice:         var(--sigma-ice);
  --bg-dark:        var(--sigma-navy);
  --bg-dark-2:      var(--sigma-navy-dark);
  --bg-card:        var(--sigma-white);

  /* Borders */
  --border-light:   rgba(13, 31, 78, 0.08);
  --border-medium:  rgba(13, 31, 78, 0.15);
  --border-strong:  rgba(13, 31, 78, 0.25);

  /* Shadows */
  --shadow-xs:   0 1px 3px rgba(13,31,78,0.06);
  --shadow-sm:   0 2px 8px rgba(13,31,78,0.08);
  --shadow-md:   0 4px 16px rgba(13,31,78,0.10);
  --shadow-lg:   0 8px 32px rgba(13,31,78,0.12);
  --shadow-xl:   0 16px 48px rgba(13,31,78,0.14);
  --shadow-card: 0 2px 12px rgba(13,31,78,0.08), 0 0 0 1px rgba(13,31,78,0.04);

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Border Radius */
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-2xl: 32px;
  --radius-full: 9999px;

  /* Typography */
  --font-arabic:  'Cairo', system-ui, sans-serif;
  --font-latin:   'Plus Jakarta Sans', system-ui, sans-serif;

  /* Font Sizes */
  --text-xs:   0.75rem;    /* 12px */
  --text-sm:   0.875rem;   /* 14px */
  --text-base: 1rem;       /* 16px */
  --text-lg:   1.125rem;   /* 18px */
  --text-xl:   1.25rem;    /* 20px */
  --text-2xl:  1.5rem;     /* 24px */
  --text-3xl:  1.875rem;   /* 30px */
  --text-4xl:  2.25rem;    /* 36px */
  --text-5xl:  3rem;       /* 48px */
  --text-6xl:  3.75rem;    /* 60px */
  --text-7xl:  4.5rem;     /* 72px */

  /* Line Heights */
  --leading-tight:   1.2;
  --leading-snug:    1.35;
  --leading-normal:  1.6;
  --leading-relaxed: 1.75;
  --leading-loose:   2;

  /* Transitions */
  --transition-fast:   150ms ease;
  --transition-base:   250ms ease;
  --transition-slow:   400ms ease;
  --transition-slower: 600ms ease;

  /* Navbar */
  --navbar-height: 76px;

  /* Z-Index */
  --z-dropdown: 100;
  --z-sticky:   200;
  --z-overlay:  300;
  --z-modal:    400;
  --z-toast:    500;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg-page);
  color: var(--text-primary);
  line-height: var(--leading-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* RTL / LTR fonts */
[dir="rtl"] body,
[lang="ar"] body {
  font-family: var(--font-arabic);
  direction: rtl;
}

[dir="ltr"] body,
[lang="fr"] body,
[lang="en"] body {
  font-family: var(--font-latin);
  direction: ltr;
}

img, video { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
ul, ol { list-style: none; }
input, textarea, select { font-family: inherit; }

/* Focus visible */
:focus-visible {
  outline: 2px solid var(--sigma-royal);
  outline-offset: 3px;
}

/* Selection */
::selection {
  background: rgba(36, 97, 197, 0.2);
  color: var(--sigma-navy);
}

/* ============================================================
   3. Typography Scale
   ============================================================ */
.sigma-h1 {
  font-size: clamp(2.25rem, 5vw, var(--text-6xl));
  font-weight: 800;
  line-height: var(--leading-tight);
  letter-spacing: -0.02em;
  color: var(--sigma-navy);
}

.sigma-h2 {
  font-size: clamp(1.75rem, 3.5vw, var(--text-4xl));
  font-weight: 700;
  line-height: var(--leading-snug);
  letter-spacing: -0.015em;
  color: var(--sigma-navy);
}

.sigma-h3 {
  font-size: clamp(1.25rem, 2.5vw, var(--text-2xl));
  font-weight: 600;
  line-height: var(--leading-snug);
  color: var(--sigma-navy);
}

.sigma-h4 {
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--sigma-navy);
}

.sigma-body-lg {
  font-size: var(--text-lg);
  line-height: var(--leading-relaxed);
  color: var(--sigma-gray-600);
}

.sigma-body {
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  color: var(--sigma-gray-600);
}

.sigma-body-sm {
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  color: var(--sigma-gray-500);
}

.sigma-caption {
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--sigma-gray-400);
}

/* ============================================================
   4. Layout Utilities
   ============================================================ */
.sigma-container {
  width: 100%;
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: var(--space-6);
}

@media (min-width: 640px) {
  .sigma-container { padding-inline: var(--space-8); }
}

@media (min-width: 1024px) {
  .sigma-container { padding-inline: var(--space-12); }
}

.sigma-section {
  padding-block: var(--space-20);
}

.sigma-section-sm {
  padding-block: var(--space-12);
}

.sigma-section-lg {
  padding-block: var(--space-32);
}

.sigma-section-header {
  text-align: center;
  max-width: 640px;
  margin-inline: auto;
  margin-bottom: var(--space-16);
}

.sigma-section-header .sigma-caption {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-4);
  background: var(--sigma-ice);
  color: var(--sigma-royal);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-4);
  border: 1px solid rgba(36,97,197,0.15);
}

.sigma-section-header .sigma-h2 {
  margin-bottom: var(--space-4);
}

.sigma-section-header .sigma-body-lg {
  max-width: 520px;
  margin-inline: auto;
}

/* ============================================================
   5. Buttons
   ============================================================ */
.sigma-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  font-weight: 600;
  font-family: inherit;
  line-height: 1;
  transition: all var(--transition-base);
  white-space: nowrap;
  cursor: pointer;
  border: 2px solid transparent;
  text-decoration: none;
}

.sigma-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Primary */
.sigma-btn-primary {
  background: var(--sigma-navy);
  color: var(--text-on-dark);
  border-color: var(--sigma-navy);
}

.sigma-btn-primary:hover {
  background: var(--sigma-blue);
  border-color: var(--sigma-blue);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(13,31,78,0.25);
}

.sigma-btn-primary:active {
  transform: translateY(0);
  box-shadow: none;
}

/* Royal */
.sigma-btn-royal {
  background: var(--sigma-royal);
  color: var(--text-on-dark);
  border-color: var(--sigma-royal);
}

.sigma-btn-royal:hover {
  background: #1a4ea8;
  border-color: #1a4ea8;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(36,97,197,0.3);
}

/* Outline */
.sigma-btn-outline {
  background: transparent;
  color: var(--sigma-navy);
  border-color: var(--sigma-navy);
}

.sigma-btn-outline:hover {
  background: var(--sigma-navy);
  color: var(--text-on-dark);
  transform: translateY(-1px);
}

/* Outline White (for dark backgrounds) */
.sigma-btn-outline-white {
  background: transparent;
  color: var(--text-on-dark);
  border-color: rgba(255,255,255,0.5);
}

.sigma-btn-outline-white:hover {
  background: rgba(255,255,255,0.12);
  border-color: white;
}

/* Ghost */
.sigma-btn-ghost {
  background: transparent;
  color: var(--sigma-gray-600);
  border-color: transparent;
}

.sigma-btn-ghost:hover {
  background: var(--sigma-gray-100);
  color: var(--sigma-navy);
}

/* Sizes */
.sigma-btn-sm {
  padding: 0.5rem 1.25rem;
  font-size: var(--text-sm);
  border-radius: var(--radius-sm);
}

.sigma-btn-lg {
  padding: 1rem 2.25rem;
  font-size: var(--text-lg);
  border-radius: var(--radius-lg);
}

/* Loading state */
.sigma-btn.loading {
  opacity: 0.7;
  pointer-events: none;
}

.sigma-btn.loading::after {
  content: '';
  width: 1rem;
  height: 1rem;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: sigma-spin 0.7s linear infinite;
  margin-inline-start: var(--space-2);
}

/* ============================================================
   6. Cards
   ============================================================ */
.sigma-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: all var(--transition-base);
}

.sigma-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
  border-color: var(--border-medium);
}

.sigma-card-body {
  padding: var(--space-6);
}

.sigma-card-lg .sigma-card-body {
  padding: var(--space-8);
}

/* Feature Card */
.sigma-feature-card {
  background: var(--sigma-white);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  border: 1px solid var(--border-light);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.sigma-feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--sigma-navy), var(--sigma-royal));
  opacity: 0;
  transition: opacity var(--transition-base);
}

.sigma-feature-card:hover {
  border-color: var(--border-medium);
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.sigma-feature-card:hover::before {
  opacity: 1;
}

.sigma-feature-icon {
  width: 52px;
  height: 52px;
  background: var(--sigma-ice);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-5);
  transition: all var(--transition-base);
}

.sigma-feature-card:hover .sigma-feature-icon {
  background: var(--sigma-navy);
}

.sigma-feature-icon svg,
.sigma-feature-icon span {
  color: var(--sigma-navy);
  width: 24px;
  height: 24px;
  font-size: 24px;
  transition: color var(--transition-base);
}

.sigma-feature-card:hover .sigma-feature-icon svg,
.sigma-feature-card:hover .sigma-feature-icon span {
  color: white;
}

/* Stat Card */
.sigma-stat-card {
  text-align: center;
  padding: var(--space-8);
}

.sigma-stat-number {
  font-size: clamp(2rem, 4vw, 3.5rem);
  font-weight: 800;
  color: var(--sigma-navy);
  line-height: 1;
  letter-spacing: -0.03em;
}

.sigma-stat-label {
  font-size: var(--text-sm);
  color: var(--sigma-gray-500);
  font-weight: 500;
  margin-top: var(--space-2);
}

/* ============================================================
   7. Badge
   ============================================================ */
.sigma-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.sigma-badge-navy {
  background: var(--sigma-navy);
  color: white;
}

.sigma-badge-blue {
  background: var(--sigma-ice);
  color: var(--sigma-royal);
  border: 1px solid rgba(36,97,197,0.2);
}

.sigma-badge-success {
  background: #ecfdf5;
  color: #059669;
  border: 1px solid rgba(5,150,105,0.2);
}

/* ============================================================
   8. Form Elements
   ============================================================ */
.sigma-form-group {
  margin-bottom: var(--space-5);
}

.sigma-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--sigma-gray-700);
  margin-bottom: var(--space-2);
}

.sigma-input,
.sigma-textarea,
.sigma-select {
  width: 100%;
  padding: 0.75rem 1rem;
  background: var(--sigma-white);
  border: 1.5px solid var(--border-medium);
  border-radius: var(--radius-md);
  font-family: inherit;
  font-size: var(--text-base);
  color: var(--text-primary);
  transition: all var(--transition-fast);
  -webkit-appearance: none;
}

.sigma-input::placeholder,
.sigma-textarea::placeholder {
  color: var(--sigma-gray-400);
}

.sigma-input:focus,
.sigma-textarea:focus,
.sigma-select:focus {
  outline: none;
  border-color: var(--sigma-royal);
  box-shadow: 0 0 0 3px rgba(36,97,197,0.12);
}

.sigma-input.error,
.sigma-textarea.error {
  border-color: #ef4444;
  box-shadow: 0 0 0 3px rgba(239,68,68,0.1);
}

.sigma-input.success,
.sigma-textarea.success {
  border-color: #10b981;
}

.sigma-textarea {
  resize: vertical;
  min-height: 120px;
}

.sigma-form-error {
  font-size: var(--text-xs);
  color: #ef4444;
  margin-top: var(--space-1);
  display: none;
}

.sigma-form-error.visible {
  display: block;
}

/* ============================================================
   9. Divider
   ============================================================ */
.sigma-divider {
  height: 1px;
  background: var(--border-light);
  border: none;
  margin-block: var(--space-8);
}

/* ============================================================
   10. Geometric Decorations (SIGMA Visual Language)
   ============================================================ */
.sigma-geo-dots {
  background-image: radial-gradient(circle, rgba(13,31,78,0.07) 1px, transparent 1px);
  background-size: 20px 20px;
}

.sigma-geo-grid {
  background-image:
    linear-gradient(rgba(13,31,78,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(13,31,78,0.04) 1px, transparent 1px);
  background-size: 40px 40px;
}

.sigma-geo-line {
  position: relative;
}

.sigma-geo-line::before {
  content: '';
  position: absolute;
  top: 50%;
  width: 60px;
  height: 2px;
  background: var(--sigma-royal);
}

[dir="rtl"] .sigma-geo-line::before { right: 0; }
[dir="ltr"] .sigma-geo-line::before { left: 0; }

/* Sigma shape decoration */
.sigma-shape-sigma {
  font-family: 'Plus Jakarta Sans', serif;
  font-weight: 900;
  font-size: 200px;
  color: rgba(13,31,78,0.04);
  line-height: 1;
  pointer-events: none;
  user-select: none;
  position: absolute;
}

/* ============================================================
   11. Animations
   ============================================================ */
@keyframes sigma-spin {
  to { transform: rotate(360deg); }
}

@keyframes sigma-fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes sigma-fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes sigma-slideInRight {
  from { opacity: 0; transform: translateX(24px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes sigma-slideInLeft {
  from { opacity: 0; transform: translateX(-24px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes sigma-countUp {
  from { opacity: 0; transform: scale(0.8); }
  to   { opacity: 1; transform: scale(1); }
}

@keyframes sigma-pulse-ring {
  0%   { transform: scale(1); opacity: 0.4; }
  100% { transform: scale(2.5); opacity: 0; }
}

/* Scroll reveal classes */
.sigma-reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.sigma-reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.sigma-reveal-delay-1 { transition-delay: 0.1s; }
.sigma-reveal-delay-2 { transition-delay: 0.2s; }
.sigma-reveal-delay-3 { transition-delay: 0.3s; }
.sigma-reveal-delay-4 { transition-delay: 0.4s; }
.sigma-reveal-delay-5 { transition-delay: 0.5s; }
.sigma-reveal-delay-6 { transition-delay: 0.6s; }

/* ============================================================
   12. NAVBAR
   ============================================================ */
.sigma-navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-sticky);
  height: var(--navbar-height);
  display: flex;
  align-items: center;
  transition: all var(--transition-base);
  background: transparent;
}

.sigma-navbar.scrolled {
  background: rgba(255,255,255,0.96);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 20px rgba(13,31,78,0.08);
  border-bottom: 1px solid var(--border-light);
}

.sigma-navbar.dark-mode {
  background: rgba(8,15,40,0.95);
  backdrop-filter: blur(20px);
}

.sigma-navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: var(--space-6);
}

.sigma-navbar-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
  text-decoration: none;
}

.sigma-navbar-logo img {
  height: 44px;
  width: auto;
  object-fit: contain;
}

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

.sigma-navbar-logo-text .logo-main {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--sigma-navy);
  letter-spacing: -0.01em;
}

.sigma-navbar-logo-text .logo-sub {
  font-size: 0.6rem;
  font-weight: 600;
  color: var(--sigma-royal);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

/* Nav Links */
.sigma-navbar-links {
  display: none;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
}

@media (min-width: 1024px) {
  .sigma-navbar-links { display: flex; }
}

.sigma-navbar-links a {
  display: inline-flex;
  align-items: center;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--sigma-gray-700);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.sigma-navbar-links a:hover,
.sigma-navbar-links a.active {
  color: var(--sigma-navy);
  background: var(--sigma-ice);
}

.sigma-navbar-links a.active {
  font-weight: 600;
}

/* Navbar Actions */
.sigma-navbar-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* Language Switcher */
.sigma-lang-switcher {
  display: flex;
  align-items: center;
  gap: 2px;
  background: var(--sigma-gray-100);
  border-radius: var(--radius-sm);
  padding: 2px;
}

.sigma-lang-btn {
  padding: 4px 8px;
  border-radius: calc(var(--radius-sm) - 2px);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--sigma-gray-500);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
  background: transparent;
  font-family: inherit;
  text-decoration: none;
  display: inline-block;
}

.sigma-lang-btn.active {
  background: var(--sigma-white);
  color: var(--sigma-navy);
  box-shadow: var(--shadow-xs);
}

.sigma-lang-btn:hover:not(.active) {
  color: var(--sigma-navy);
}

/* Mobile menu toggle */
.sigma-mobile-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: transparent;
  border: 1.5px solid var(--border-medium);
  color: var(--sigma-navy);
  cursor: pointer;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.sigma-mobile-toggle:hover {
  background: var(--sigma-ice);
  border-color: var(--sigma-royal);
}

@media (min-width: 1024px) {
  .sigma-mobile-toggle { display: none; }
}

/* Mobile menu icon lines */
.sigma-toggle-icon {
  display: flex;
  flex-direction: column;
  gap: 5px;
  width: 20px;
}

.sigma-toggle-icon span {
  display: block;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: all var(--transition-base);
  transform-origin: center;
}

.sigma-mobile-toggle.open .sigma-toggle-icon span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.sigma-mobile-toggle.open .sigma-toggle-icon span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}
.sigma-mobile-toggle.open .sigma-toggle-icon span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ============================================================
   13. MOBILE MENU
   ============================================================ */
.sigma-mobile-menu {
  position: fixed;
  top: var(--navbar-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255,255,255,0.98);
  backdrop-filter: blur(20px);
  z-index: calc(var(--z-sticky) - 1);
  transform: translateX(-100%);
  transition: transform var(--transition-slow);
  overflow-y: auto;
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
}

[dir="rtl"] .sigma-mobile-menu {
  transform: translateX(100%);
}

.sigma-mobile-menu.open {
  transform: translateX(0);
}

.sigma-mobile-menu-links {
  list-style: none;
  margin-bottom: var(--space-8);
}

.sigma-mobile-menu-links a {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--sigma-gray-700);
  transition: all var(--transition-fast);
  text-decoration: none;
  border-bottom: 1px solid var(--border-light);
}

.sigma-mobile-menu-links a:last-child { border-bottom: none; }

.sigma-mobile-menu-links a:hover,
.sigma-mobile-menu-links a.active {
  color: var(--sigma-navy);
  background: var(--sigma-ice);
  padding-inline-start: var(--space-6);
}

/* ============================================================
   14. FOOTER
   ============================================================ */
.sigma-footer {
  background: var(--sigma-navy-dark);
  color: var(--text-on-dark-2);
  padding-top: var(--space-20);
  padding-bottom: var(--space-8);
  position: relative;
  overflow: hidden;
}

.sigma-footer::before {
  content: 'Σ';
  position: absolute;
  font-size: 400px;
  font-weight: 900;
  color: rgba(255,255,255,0.02);
  line-height: 1;
  bottom: -80px;
  pointer-events: none;
  user-select: none;
}

[dir="rtl"] .sigma-footer::before { right: -60px; }
[dir="ltr"] .sigma-footer::before { left: -60px; }

.sigma-footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-16);
}

@media (min-width: 640px) {
  .sigma-footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .sigma-footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; gap: var(--space-8); }
}

.sigma-footer-brand .sigma-navbar-logo-text .logo-main {
  color: white;
  font-size: 1.5rem;
}

.sigma-footer-brand .sigma-navbar-logo-text .logo-sub {
  color: var(--text-on-dark-3);
}

.sigma-footer-tagline {
  font-size: var(--text-sm);
  color: var(--text-on-dark-3);
  line-height: var(--leading-relaxed);
  margin-top: var(--space-4);
  max-width: 280px;
}

.sigma-footer-col h4 {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-on-dark-3);
  margin-bottom: var(--space-5);
}

.sigma-footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.sigma-footer-links a {
  font-size: var(--text-sm);
  color: var(--text-on-dark-2);
  transition: color var(--transition-fast);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.sigma-footer-links a:hover {
  color: white;
}

.sigma-footer-social {
  display: flex;
  gap: var(--space-3);
  margin-top: var(--space-5);
  flex-wrap: wrap;
}

.sigma-social-btn {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.07);
  border: 1px solid rgba(255,255,255,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-on-dark-2);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.sigma-social-btn:hover {
  background: rgba(255,255,255,0.15);
  color: white;
  transform: translateY(-2px);
}

.sigma-footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding-top: var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.sigma-footer-copyright {
  font-size: var(--text-sm);
  color: var(--text-on-dark-3);
}

/* ============================================================
   15. Hero Section
   ============================================================ */
.sigma-hero {
  min-height: 100svh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  background: var(--sigma-white);
  padding-top: var(--navbar-height);
}

.sigma-hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

/* Blue blob top right */
.sigma-hero-bg::before {
  content: '';
  position: absolute;
  top: -200px;
  width: 700px;
  height: 700px;
  border-radius: 50%;
  background: radial-gradient(circle at center, rgba(36,97,197,0.08) 0%, transparent 70%);
}

[dir="rtl"] .sigma-hero-bg::before { left: -200px; }
[dir="ltr"] .sigma-hero-bg::before { right: -200px; }

/* Navy blob bottom */
.sigma-hero-bg::after {
  content: '';
  position: absolute;
  bottom: -100px;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: radial-gradient(circle at center, rgba(13,31,78,0.05) 0%, transparent 70%);
}

[dir="rtl"] .sigma-hero-bg::after { right: -100px; }
[dir="ltr"] .sigma-hero-bg::after { left: -100px; }

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

.sigma-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  align-items: center;
  gap: var(--space-12);
}

@media (min-width: 1024px) {
  .sigma-hero-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-16);
    min-height: calc(100svh - var(--navbar-height));
  }
}

.sigma-hero-text .sigma-caption {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: var(--sigma-ice);
  color: var(--sigma-royal);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-6);
  border: 1px solid rgba(36,97,197,0.15);
}

.sigma-hero-title {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--sigma-navy);
  margin-bottom: var(--space-6);
}

.sigma-hero-title .sigma-brand {
  color: var(--sigma-royal);
  position: relative;
}

.sigma-hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--sigma-gray-600);
  line-height: var(--leading-relaxed);
  max-width: 500px;
  margin-bottom: var(--space-8);
}

.sigma-hero-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.sigma-hero-subjects {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-8);
  flex-wrap: wrap;
}

.sigma-subject-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--sigma-white);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--sigma-navy);
  box-shadow: var(--shadow-xs);
}

.sigma-subject-chip .subject-icon {
  font-size: 16px;
}

/* Hero Visual */
.sigma-hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.sigma-hero-phone {
  position: relative;
  max-width: 300px;
  margin: 0 auto;
  filter: drop-shadow(var(--shadow-xl));
  animation: sigma-float 6s ease-in-out infinite;
}

@keyframes sigma-float {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-12px); }
}

/* ============================================================
   16. Page Header (inner pages)
   ============================================================ */
.sigma-page-header {
  background: linear-gradient(135deg, var(--sigma-navy-dark) 0%, var(--sigma-navy) 60%, var(--sigma-blue) 100%);
  color: white;
  padding-top: calc(var(--navbar-height) + var(--space-16));
  padding-bottom: var(--space-16);
  position: relative;
  overflow: hidden;
}

.sigma-page-header::after {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M 0 30 L 30 0 L 60 30 L 30 60 Z' fill='none' stroke='rgba(255,255,255,0.03)' stroke-width='1'/%3E%3C/svg%3E") repeat;
}

.sigma-page-header-content {
  position: relative;
  z-index: 1;
}

.sigma-page-header .sigma-caption {
  color: rgba(255,255,255,0.6);
  margin-bottom: var(--space-4);
}

.sigma-page-header .sigma-h1 {
  color: white;
  margin-bottom: var(--space-4);
}

.sigma-page-header .sigma-body-lg {
  color: rgba(255,255,255,0.75);
  max-width: 560px;
}

/* Breadcrumb */
.sigma-breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.55);
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
}

.sigma-breadcrumb a {
  color: rgba(255,255,255,0.7);
  transition: color var(--transition-fast);
}

.sigma-breadcrumb a:hover { color: white; }

.sigma-breadcrumb .sep {
  font-size: 10px;
  opacity: 0.4;
}

/* ============================================================
   17. FAQ Accordion
   ============================================================ */
.sigma-faq-item {
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: var(--space-3);
  transition: border-color var(--transition-fast);
}

.sigma-faq-item.open {
  border-color: var(--border-medium);
  box-shadow: var(--shadow-sm);
}

.sigma-faq-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-5) var(--space-6);
  background: var(--sigma-white);
  cursor: pointer;
  border: none;
  font-family: inherit;
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--sigma-navy);
  text-align: start;
  transition: background var(--transition-fast);
}

.sigma-faq-trigger:hover {
  background: var(--sigma-gray-50);
}

.sigma-faq-item.open .sigma-faq-trigger {
  background: var(--sigma-ice);
}

.sigma-faq-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 1.5px solid var(--border-medium);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--sigma-gray-500);
  transition: all var(--transition-base);
}

.sigma-faq-item.open .sigma-faq-icon {
  background: var(--sigma-navy);
  border-color: var(--sigma-navy);
  color: white;
  transform: rotate(45deg);
}

.sigma-faq-icon svg {
  width: 14px;
  height: 14px;
}

.sigma-faq-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.sigma-faq-item.open .sigma-faq-content {
  max-height: 1000px;
}

.sigma-faq-body {
  padding: var(--space-5) var(--space-6) var(--space-6);
  font-size: var(--text-base);
  color: var(--sigma-gray-600);
  line-height: var(--leading-relaxed);
  border-top: 1px solid var(--border-light);
}

/* ============================================================
   18. Loading & States
   ============================================================ */
.sigma-skeleton {
  background: linear-gradient(90deg, var(--sigma-gray-100) 25%, var(--sigma-gray-200) 50%, var(--sigma-gray-100) 75%);
  background-size: 200% 100%;
  animation: sigma-skeleton 1.5s infinite;
  border-radius: var(--radius-sm);
}

@keyframes sigma-skeleton {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.sigma-empty-state {
  text-align: center;
  padding: var(--space-16) var(--space-8);
  color: var(--sigma-gray-400);
}

.sigma-empty-state svg {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--space-4);
  opacity: 0.4;
}

.sigma-error-state {
  text-align: center;
  padding: var(--space-12) var(--space-8);
  color: var(--sigma-gray-500);
}

/* Toast */
.sigma-toast-container {
  position: fixed;
  bottom: var(--space-6);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 360px;
  width: calc(100% - var(--space-12));
}

[dir="rtl"] .sigma-toast-container { right: var(--space-6); }
[dir="ltr"] .sigma-toast-container { left: var(--space-6); }

.sigma-toast {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  background: var(--sigma-navy);
  color: white;
  font-size: var(--text-sm);
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  animation: sigma-fadeUp 0.3s ease;
}

.sigma-toast.success { background: #059669; }
.sigma-toast.error   { background: #dc2626; }
.sigma-toast.info    { background: var(--sigma-royal); }

/* ============================================================
   19. Blog Card
   ============================================================ */
.sigma-blog-card {
  background: var(--sigma-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  overflow: hidden;
  transition: all var(--transition-base);
  display: flex;
  flex-direction: column;
}

.sigma-blog-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-medium);
}

.sigma-blog-card-image {
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--sigma-gray-100);
}

.sigma-blog-card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.sigma-blog-card:hover .sigma-blog-card-image img {
  transform: scale(1.04);
}

.sigma-blog-card-body {
  padding: var(--space-6);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.sigma-blog-card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}

.sigma-blog-card h3 {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--sigma-navy);
  line-height: var(--leading-snug);
  margin-bottom: var(--space-3);
  transition: color var(--transition-fast);
}

.sigma-blog-card:hover h3 {
  color: var(--sigma-royal);
}

.sigma-blog-card p {
  font-size: var(--text-sm);
  color: var(--sigma-gray-500);
  line-height: var(--leading-relaxed);
  flex: 1;
  margin-bottom: var(--space-5);
}

/* ============================================================
   20. Competition Result Table
   ============================================================ */
.sigma-results-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}

.sigma-results-table th {
  padding: var(--space-3) var(--space-4);
  background: var(--sigma-navy);
  color: white;
  font-weight: 600;
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-align: start;
}

.sigma-results-table th:first-child { border-radius: var(--radius-sm) 0 0 0; }
.sigma-results-table th:last-child  { border-radius: 0 var(--radius-sm) 0 0; }

.sigma-results-table td {
  padding: var(--space-4);
  border-bottom: 1px solid var(--border-light);
  color: var(--sigma-gray-700);
}

.sigma-results-table tr:hover td {
  background: var(--sigma-gray-50);
}

.sigma-results-table .rank-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  font-weight: 700;
  font-size: var(--text-sm);
}

.sigma-results-table .rank-1  { background: #fef3c7; color: #b45309; }
.sigma-results-table .rank-2  { background: #f3f4f6; color: #4b5563; }
.sigma-results-table .rank-3  { background: #fef3c7; color: #92400e; }
.sigma-results-table .rank-other { background: var(--sigma-ice); color: var(--sigma-navy); }

/* ============================================================
   21. Download Section
   ============================================================ */
.sigma-download-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-6);
  border-radius: var(--radius-md);
  background: var(--sigma-navy);
  color: white;
  border: 1.5px solid rgba(255,255,255,0.15);
  transition: all var(--transition-base);
  min-width: 200px;
}

.sigma-download-btn:hover {
  background: var(--sigma-blue);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.sigma-download-btn .store-icon {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}

.sigma-download-btn .store-text {
  display: flex;
  flex-direction: column;
}

.sigma-download-btn .store-label {
  font-size: var(--text-xs);
  opacity: 0.75;
  line-height: 1;
}

.sigma-download-btn .store-name {
  font-size: var(--text-base);
  font-weight: 700;
  line-height: 1.2;
}

/* ============================================================
   22. Grid Layouts
   ============================================================ */
.sigma-grid-2 {
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: var(--space-6);
}

@media (min-width: 640px) {
  .sigma-grid-2 { grid-template-columns: repeat(2, 1fr); }
}

.sigma-grid-3 {
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: var(--space-6);
}

@media (min-width: 640px) {
  .sigma-grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .sigma-grid-3 { grid-template-columns: repeat(3, 1fr); }
}

.sigma-grid-4 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
}

@media (min-width: 768px) {
  .sigma-grid-4 { grid-template-columns: repeat(4, 1fr); }
}

/* ============================================================
   23. Responsive Utilities
   ============================================================ */
.hide-mobile  { display: none; }
.show-mobile  { display: block; }

@media (min-width: 768px) {
  .hide-mobile { display: block; }
  .show-mobile { display: none; }
}

/* ============================================================
   24. Print
   ============================================================ */
@media print {
  .sigma-navbar, .sigma-footer, .sigma-mobile-menu { display: none !important; }
}