/* ==========================================================================
   IQScorePro — Commercial Design System & Stylesheet
   Modern, Trustworthy, Mobile-First Cognitive Platform
   Seamless Dual Theme Engine: Dark Mode & Light Mode
   ========================================================================== */

/* ---------- Dark Theme Tokens (Default) ---------- */
:root,
[data-theme="dark"] {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  
  /* Color Palette - Dark */
  --color-bg: #090D16;
  --color-surface: #111827;
  --color-surface-hover: #1F2937;
  --color-surface-card: rgba(17, 24, 39, 0.82);
  --color-border: rgba(255, 255, 255, 0.1);
  --color-border-focus: #6366F1;
  
  --color-text-main: #F9FAFB;
  --color-text-muted: #9CA3AF;
  --color-text-dim: #6B7280;
  
  --color-primary: #4F46E5;
  --color-primary-hover: #4338CA;
  --color-primary-glow: rgba(79, 70, 229, 0.35);
  
  --color-accent: #06B6D4;
  --color-purple: #8B5CF6;
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-danger: #EF4444;

  --nav-bg: rgba(9, 13, 22, 0.85);
  --btn-secondary-bg: rgba(255, 255, 255, 0.05);
  --btn-secondary-hover: rgba(255, 255, 255, 0.12);
  --badge-bg: rgba(79, 70, 229, 0.15);
  --badge-border: rgba(79, 70, 229, 0.3);
  --badge-text: #A5B4FC;
  --hero-title-gradient: linear-gradient(180deg, #FFFFFF 0%, #D1D5DB 100%);
  --disclaimer-bg: rgba(17, 24, 39, 0.6);
  --disclaimer-border: rgba(255, 255, 255, 0.08);
  --option-btn-bg: rgba(255, 255, 255, 0.03);
  --option-btn-hover: rgba(99, 102, 241, 0.12);
  --option-letter-bg: rgba(255, 255, 255, 0.08);
  --option-letter-color: #A5B4FC;
  --score-circle-bg: radial-gradient(circle, rgba(79, 70, 229, 0.25) 0%, rgba(17, 24, 39, 0.8) 70%);
  --score-circle-border: rgba(99, 102, 241, 0.5);
  --input-bg: rgba(17, 24, 39, 0.7);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.25), 0 2px 4px -2px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, 0.35), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 25px var(--color-primary-glow);
}

/* ---------- Light Theme Tokens ---------- */
[data-theme="light"] {
  /* Color Palette - Light */
  --color-bg: #F8FAFF;
  --color-surface: #FFFFFF;
  --color-surface-hover: #F1F5F9;
  --color-surface-card: #FFFFFF;
  --color-border: #E2E8F0;
  --color-border-focus: #4F46E5;
  
  --color-text-main: #111827;
  --color-text-muted: #4B5563;
  --color-text-dim: #6B7280;
  
  --color-primary: #4F46E5;
  --color-primary-hover: #4338CA;
  --color-primary-glow: rgba(79, 70, 229, 0.18);
  
  --color-accent: #0284C7;
  --color-purple: #7C3AED;
  --color-success: #059669;
  --color-warning: #D97706;
  --color-danger: #DC2626;

  --nav-bg: rgba(248, 250, 255, 0.88);
  --btn-secondary-bg: #F1F5F9;
  --btn-secondary-hover: #E2E8F0;
  --badge-bg: rgba(79, 70, 229, 0.1);
  --badge-border: rgba(79, 70, 229, 0.25);
  --badge-text: #4F46E5;
  --hero-title-gradient: linear-gradient(180deg, #111827 0%, #374151 100%);
  --disclaimer-bg: #F1F5F9;
  --disclaimer-border: #E2E8F0;
  --option-btn-bg: #F8FAFC;
  --option-btn-hover: #EEF2FF;
  --option-letter-bg: #E2E8F0;
  --option-letter-color: #4F46E5;
  --score-circle-bg: radial-gradient(circle, rgba(79, 70, 229, 0.12) 0%, rgba(255, 255, 255, 0.95) 70%);
  --score-circle-border: rgba(99, 102, 241, 0.35);
  --input-bg: #FFFFFF;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.06), 0 2px 4px -2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 25px -3px rgba(41, 54, 91, 0.09), 0 4px 6px -4px rgba(41, 54, 91, 0.04);
  --shadow-glow: 0 0 20px rgba(79, 70, 229, 0.2);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  overflow-x: hidden;
  transition: background-color 0.25s ease, color 0.25s ease;
}

/* Background Gradients */
.bg-ambient {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: -1;
  overflow: hidden;
}
.bg-glow-top {
  position: absolute;
  top: -15%;
  left: 50%;
  transform: translateX(-50%);
  width: 75vw;
  height: 50vw;
  max-width: 900px;
  max-height: 600px;
  background: radial-gradient(circle, rgba(79, 70, 229, 0.18) 0%, rgba(6, 182, 212, 0.08) 40%, transparent 70%);
  filter: blur(80px);
  transition: opacity 0.3s ease;
}
.bg-glow-bottom {
  position: absolute;
  bottom: -20%;
  right: 10%;
  width: 50vw;
  height: 50vw;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.12) 0%, transparent 70%);
  filter: blur(90px);
  transition: opacity 0.3s ease;
}

[data-theme="light"] .bg-glow-top {
  background: radial-gradient(circle, rgba(79, 70, 229, 0.08) 0%, rgba(6, 182, 212, 0.04) 40%, transparent 70%);
}
[data-theme="light"] .bg-glow-bottom {
  background: radial-gradient(circle, rgba(139, 92, 246, 0.05) 0%, transparent 70%);
}

/* Layout Containers */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}
.container-narrow {
  max-width: 800px;
}

/* Navbar */
.nav-header {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: var(--nav-bg);
  transition: background-color 0.25s ease, border-color 0.25s ease;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--color-text-main);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  transition: opacity 0.2s ease;
}
.brand:hover {
  opacity: 0.92;
}
.brand img.logo-img {
  height: 32px;
  width: auto;
  object-fit: contain;
  display: inline-block;
  transition: transform 0.2s ease;
}
.brand:hover img.logo-img {
  transform: scale(1.02);
}
@media (max-width: 640px) {
  .brand img.logo-img {
    height: 26px;
  }
}
html[data-theme="dark"] .brand .logo-light {
  display: none !important;
}
html[data-theme="dark"] .brand .logo-dark {
  display: inline-block !important;
}
html:not([data-theme="dark"]) .brand .logo-dark {
  display: none !important;
}
html:not([data-theme="dark"]) .brand .logo-light {
  display: inline-block !important;
}
.brand-icon {
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: 0 0 15px var(--color-primary-glow);
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}
.nav-link {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 500;
  transition: color 0.2s ease;
}
.nav-link:hover {
  color: var(--color-text-main);
}

/* Theme Toggle Button Component */
.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background: var(--btn-secondary-bg);
  border: 1px solid var(--color-border);
  color: var(--color-text-main);
  cursor: pointer;
  transition: all 0.2s ease;
  flex-shrink: 0;
  padding: 0;
}
.theme-toggle-btn:hover {
  background: var(--btn-secondary-hover);
  border-color: var(--color-border-focus);
  transform: translateY(-1px);
  color: var(--color-primary);
}
.theme-toggle-btn:active {
  transform: translateY(0);
}
.theme-icon-sun, .theme-icon-moon {
  transition: transform 0.3s ease;
}
.theme-toggle-btn:hover .theme-icon-sun {
  transform: rotate(30deg);
}
.theme-toggle-btn:hover .theme-icon-moon {
  transform: rotate(-15deg);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.9375rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: inherit;
  user-select: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), #6366F1);
  color: #ffffff;
  box-shadow: var(--shadow-glow);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 0 30px rgba(79, 70, 229, 0.5);
}
.btn-primary:active {
  transform: translateY(0);
}
.btn-secondary {
  background-color: var(--btn-secondary-bg);
  color: var(--color-text-main);
  border-color: var(--color-border);
}
.btn-secondary:hover {
  background-color: var(--btn-secondary-hover);
  border-color: var(--color-border-focus);
}
.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.0625rem;
}

/* Hero Section */
.hero {
  padding: 5rem 0 3rem;
  text-align: center;
}
.badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.375rem 1rem;
  background-color: var(--badge-bg);
  border: 1px solid var(--badge-border);
  border-radius: var(--radius-full);
  color: var(--badge-text);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1.5rem;
  transition: background-color 0.25s ease, color 0.25s ease;
}
.badge-dot {
  width: 7px;
  height: 7px;
  background-color: var(--color-accent);
  border-radius: 50%;
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.2); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.hero-title {
  font-size: 3.25rem;
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
  background: var(--hero-title-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-subtitle {
  font-size: 1.25rem;
  color: var(--color-text-muted);
  max-width: 680px;
  margin: 0 auto 2.5rem;
  line-height: 1.6;
}
.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 3.5rem;
}

/* Stats Ribbon */
.stats-ribbon {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  max-width: 780px;
  margin: 0 auto 4rem;
  background-color: var(--color-surface-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem 2rem;
  box-shadow: var(--shadow-md);
  transition: background-color 0.25s ease, border-color 0.25s ease;
}
.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
}
.stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text-main);
  letter-spacing: -0.02em;
}
.stat-label {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: 0.25rem;
}

/* Feature Grid */
.features-section {
  padding: 4rem 0;
}
.section-header {
  text-align: center;
  margin-bottom: 3rem;
}
.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
  color: var(--color-text-main);
}
.section-desc {
  color: var(--color-text-muted);
  font-size: 1.0625rem;
  max-width: 600px;
  margin: 0 auto;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}
.card {
  background-color: var(--color-surface-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 2rem;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  box-shadow: var(--shadow-md);
  transition: border-color 0.2s, transform 0.2s, background-color 0.25s ease, box-shadow 0.2s;
}
.card:hover {
  border-color: rgba(99, 102, 241, 0.4);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}
.card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--badge-bg);
  color: var(--badge-text);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
}
.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--color-text-main);
}
.card-desc {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
  line-height: 1.5;
}

/* Legal Notice / Disclaimers Box */
.disclaimer-box {
  background-color: var(--disclaimer-bg);
  border: 1px solid var(--disclaimer-border);
  border-left: 4px solid var(--color-accent);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  margin: 3rem 0;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.5;
  transition: background-color 0.25s ease, border-color 0.25s ease;
}
.disclaimer-box strong {
  color: var(--color-text-main);
}

/* Assessment Runner Styles */
.assessment-container {
  max-width: 760px;
  margin: 2rem auto 4rem;
  padding: 0 1rem;
}
.progress-bar-container {
  width: 100%;
  height: 6px;
  background-color: var(--color-border);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: 1.5rem;
}
.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transition: width 0.3s ease;
}

.question-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  font-size: 0.875rem;
}
.question-badge {
  color: var(--badge-text);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.timer-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--color-text-muted);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
}

.question-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-lg);
  transition: background-color 0.25s ease, border-color 0.25s ease;
}
.question-prompt {
  font-size: 1.375rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 2rem;
  color: var(--color-text-main);
}

.options-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}
.option-btn {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  width: 100%;
  padding: 1.125rem 1.5rem;
  background-color: var(--option-btn-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-main);
  font-size: 1.0625rem;
  text-align: left;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: inherit;
}
.option-btn:hover {
  background-color: var(--option-btn-hover);
  border-color: rgba(99, 102, 241, 0.4);
}
.option-btn.selected {
  background-color: rgba(79, 70, 229, 0.18);
  border-color: var(--color-primary);
  box-shadow: 0 0 15px rgba(79, 70, 229, 0.25);
}
.option-letter {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background-color: var(--option-letter-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9375rem;
  color: var(--option-letter-color);
  flex-shrink: 0;
}
.option-btn.selected .option-letter {
  background-color: var(--color-primary);
  color: #fff;
}

/* Result & Score Screen */
.result-hero {
  text-align: center;
  padding: 3rem 0;
}
.score-circle {
  width: 190px;
  height: 190px;
  border-radius: 50%;
  margin: 0 auto 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--score-circle-bg);
  border: 2px solid var(--score-circle-border);
  box-shadow: 0 0 40px var(--color-primary-glow);
  transition: background 0.25s ease, border-color 0.25s ease;
}
.score-value {
  font-size: 3.75rem;
  font-weight: 800;
  line-height: 1;
  color: var(--color-text-main);
}
.score-label {
  font-size: 0.8125rem;
  color: var(--badge-text);
  text-transform: uppercase;
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-top: 0.25rem;
}

/* Form Inputs */
.input-field,
input[type="text"],
input[type="email"],
input[type="tel"],
select {
  background-color: var(--input-bg);
  border: 1px solid var(--color-border);
  color: var(--color-text-main);
  border-radius: var(--radius-sm);
  transition: border-color 0.2s, background-color 0.25s;
}
.input-field:focus,
input:focus,
select:focus {
  outline: none;
  border-color: var(--color-border-focus);
}

/* Footer */
.footer {
  border-top: 1px solid var(--color-border);
  padding: 4rem 0 2.5rem;
  margin-top: 5rem;
  color: var(--color-text-dim);
  font-size: 0.875rem;
  transition: border-color 0.25s ease;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}
.footer-col h4 {
  color: var(--color-text-main);
  font-size: 0.9375rem;
  margin-bottom: 1.25rem;
  font-weight: 600;
}
.footer-col ul {
  list-style: none;
}
.footer-col li {
  margin-bottom: 0.625rem;
}
.footer-col a {
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-col a:hover {
  color: var(--color-text-main);
}
.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2.25rem;
  }
  .hero-subtitle {
    font-size: 1.0625rem;
  }
  .stats-ribbon {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }
  .question-card {
    padding: 1.5rem;
  }
  .nav-links {
    display: none;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}