/* ==========================================================================
   Architect Cert Landing Page — Design System
   Mirrors OmniTrade structure with orange accent for Architect Cert branding
   ========================================================================== */

/* CSS Custom Properties (Design Tokens)
   ========================================================================== */
:root {
  /* Colors — Orange Palette */
  --color-primary: #EA580C;
  --color-primary-dark: #C2410C;
  --color-primary-darker: #9A3412;
  --color-primary-light: #FFF7ED;
  --color-primary-glow: rgba(234, 88, 12, 0.15);

  /* Neutrals */
  --color-text: #0F172A;
  --color-text-secondary: #475569;
  --color-text-muted: #94A3B8;
  --color-background: #FAFBFC;
  --color-white: #FFFFFF;
  --color-border: #E2E8F0;
  --color-border-light: #F1F5F9;

  /* Accents */
  --color-success: #16A34A;
  --color-success-bg: #F0FDF4;
  --color-terminal-bg: #0F172A;
  --color-terminal-header: #1E293B;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', SFMono-Regular, ui-monospace, Consolas, monospace;

  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1.125rem;
  --text-lg: 1.25rem;
  --text-xl: 1.5rem;
  --text-2xl: 1.875rem;
  --text-3xl: 2.5rem;
  --text-4xl: 3rem;
  --text-5xl: 4rem;
  --text-6xl: 4.5rem;

  /* 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-7: 1.75rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Layout */
  --container-max: 1360px;
  --container-padding: clamp(20px, 5vw, 80px);
  --section-padding: 100px;

  /* Effects */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.08);
  --shadow-xl: 0 24px 48px rgba(0, 0, 0, 0.12);
  --shadow-card: 0 20px 60px rgba(0, 0, 0, 0.12);
  --shadow-glow: 0 0 60px var(--color-primary-glow);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --radius-2xl: 28px;
  --radius-full: 9999px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-background);
}

img, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

code {
  font-family: var(--font-mono);
}

/* Layout
   ========================================================================== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: var(--section-padding) 0;
  position: relative;
}

.section--alt {
  background-color: var(--color-white);
}

.section--compact {
  min-height: auto;
  padding: 80px 0;
}

.section > .container {
  width: 100%;
}

/* Animation Classes
   ========================================================================== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }
.fade-in-delay-4 { transition-delay: 0.4s; }
.fade-in-delay-5 { transition-delay: 0.5s; }

/* Header
   ========================================================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(250, 251, 252, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border-light);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.logo__symbol {
  color: var(--color-primary);
  flex-shrink: 0;
}

.logo__text {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.header__link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

.header__link:hover {
  color: var(--color-primary);
}

.header__cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-white);
  background: var(--color-text);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
}

.header__cta:hover {
  background: var(--color-primary);
  transform: translateY(-1px);
}

.header__cta--back {
  padding: var(--space-2) var(--space-3);
}

/* Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  padding: 14px 28px;
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
  white-space: nowrap;
}

.btn__icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.btn--primary {
  color: var(--color-white);
  background: var(--color-primary);
  box-shadow: 0 4px 16px rgba(234, 88, 12, 0.3);
}

.btn--primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(234, 88, 12, 0.4);
}

.btn--secondary {
  color: var(--color-text);
  background: var(--color-white);
  border: 1.5px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.btn--secondary:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Hero Section
   ========================================================================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 72px;
  overflow: hidden;
  background: linear-gradient(180deg, var(--color-background) 0%, var(--color-white) 100%);
}

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

@media (min-width: 1024px) {
  .hero__grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-20);
  }
}

.hero__content {
  max-width: 560px;
}

.hero__label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  margin-bottom: var(--space-8);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-primary-light);
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.hero__title {
  font-size: clamp(2.25rem, 5vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-6);
}

.hero__title span {
  color: var(--color-primary);
}

.hero__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-10);
  max-width: 480px;
}

/* Hero stats */
.hero__stats {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  margin-bottom: var(--space-10);
  flex-wrap: wrap;
}

.hero__stat {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.hero__stat-number {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--color-primary);
  letter-spacing: -0.03em;
  line-height: 1;
}

.hero__stat-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: 2px;
}

.hero__stat-divider {
  width: 1px;
  height: 32px;
  background: var(--color-border);
}

.hero__buttons {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
}

/* Hero Card Demo (Learning Card Animation)
   ========================================================================== */
.hero__card-demo {
  position: relative;
  width: 100%;
  max-width: 520px;
  margin: 0 auto;
}

.card-stack {
  position: relative;
  width: 100%;
}

/* Back card (depth effect) */
.learning-card--back {
  position: absolute;
  top: 12px;
  left: 12px;
  right: -12px;
  bottom: -12px;
  background: var(--color-border-light);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
}

/* Main card */
.learning-card--main {
  position: relative;
  background: var(--color-white);
  border-radius: var(--radius-xl);
  border: 1.5px solid var(--color-border);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: transform var(--transition-base);
  animation: cardPopIn 0.8s cubic-bezier(0.34, 1.56, 0.64, 1) 0.5s both;
}

@keyframes cardPopIn {
  from {
    opacity: 0;
    transform: translateY(40px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.learning-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-5) var(--space-6);
  border-bottom: 1px solid var(--color-border-light);
  background: var(--color-background);
}

.learning-card__domain {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.domain-badge {
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.domain-badge--d1 {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.learning-card__task {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
}

.difficulty--medium {
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  background: #FEF9C3;
  color: #854D0E;
}

.learning-card__question {
  padding: var(--space-6);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-text);
  font-weight: 500;
  border-bottom: 1px solid var(--color-border-light);
}

.learning-card__options {
  padding: var(--space-4) var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.card-option {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  border: 1.5px solid var(--color-border);
  font-size: var(--text-sm);
  font-weight: 400;
  color: var(--color-text);
  text-align: left;
  transition: all var(--transition-fast);
  cursor: pointer;
  line-height: 1.5;
  background: var(--color-white);
}

.card-option:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}

.card-option--selected {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}

.card-option--correct.revealed {
  border-color: var(--color-success);
  background: var(--color-success-bg);
  color: var(--color-success);
}

.card-option--wrong.revealed {
  border-color: #F87171;
  background: #FEF2F2;
  color: #B91C1C;
  opacity: 0.6;
}

.card-option__letter {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  border-radius: var(--radius-sm);
  background: var(--color-border-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-text-secondary);
  margin-top: 1px;
}

.card-option--correct .card-option__letter {
  background: var(--color-success);
  color: white;
}

.learning-card__footer {
  padding: var(--space-4) var(--space-6);
  background: var(--color-background);
  border-top: 1px solid var(--color-border-light);
}

.learning-card__progress {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.progress-bar {
  flex: 1;
  height: 4px;
  background: var(--color-border);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar__fill {
  height: 100%;
  background: var(--color-primary);
  border-radius: var(--radius-full);
  transition: width 1s ease;
}

.progress-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  white-space: nowrap;
}

/* Card result overlay */
.learning-card__result {
  display: none;
  padding: var(--space-6);
  background: var(--color-white);
  border-top: 1px solid var(--color-border-light);
}

.learning-card__result.visible {
  display: block;
  animation: fadeInUp 0.3s ease;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.result-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-4);
}

.result-icon--correct {
  background: var(--color-success-bg);
  color: var(--color-success);
}

.result-text {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-5);
}

.result-followup {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.result-followup__label {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.result-btn {
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  background: var(--color-primary);
  color: white;
  transition: all var(--transition-fast);
}

.result-btn:hover {
  background: var(--color-primary-dark);
}

.result-btn--ghost {
  background: var(--color-background);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}

.result-btn--ghost:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* Floating badges on hero card */
.hero__badge-float {
  position: absolute;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: var(--color-white);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--color-border);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-secondary);
  white-space: nowrap;
  z-index: 10;
}

.hero__badge-float svg {
  color: var(--color-primary);
  flex-shrink: 0;
}

.hero__badge-float--sm2 {
  top: -12px;
  right: -8px;
  animation: floatBadge 0.6s ease 1.2s both;
}

.hero__badge-float--grading {
  bottom: -8px;
  left: -8px;
  animation: floatBadge 0.6s ease 1.5s both;
}

@keyframes floatBadge {
  from { opacity: 0; transform: scale(0.8) translateY(8px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

/* Conversation / Demo Section
   ========================================================================== */
.conversation {
  max-width: 720px;
  margin: 0 auto;
  width: 100%;
}

.conversation__title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  text-align: center;
}

.conversation__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-12);
  text-align: center;
}

.chat {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.chat__message {
  display: flex;
  gap: var(--space-4);
  align-items: flex-start;
}

.chat__message--user {
  flex-direction: row-reverse;
}

.chat__avatar {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 700;
}

.chat__avatar--user {
  background: var(--color-primary);
  color: white;
}

.chat__avatar--assistant {
  background: var(--color-text);
  color: white;
}

.chat__bubble {
  max-width: 520px;
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  line-height: 1.7;
}

.chat__message--user .chat__bubble {
  background: var(--color-primary);
  color: white;
  border-bottom-right-radius: 4px;
}

.chat__message--assistant .chat__bubble {
  background: var(--color-white);
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
  border-bottom-left-radius: 4px;
  box-shadow: var(--shadow-sm);
}

.chat__correct {
  font-weight: 700;
  color: var(--color-success);
}

.chat__actions {
  display: flex;
  gap: var(--space-2);
  margin-top: var(--space-4);
  flex-wrap: wrap;
}

.chat__action {
  display: inline-block;
  padding: 5px 12px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  background: var(--color-background);
}

.chat__action--primary {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

/* Features Section
   ========================================================================== */
.features__header {
  text-align: center;
  margin-bottom: var(--space-16);
}

.features__title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.features__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
}

.features__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
  margin-bottom: var(--space-12);
}

.feature-card {
  padding: var(--space-10);
  background: var(--color-white);
  border-radius: var(--radius-xl);
  border: 1.5px solid var(--color-border);
  transition: all var(--transition-base);
}

.feature-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 8px 32px rgba(234, 88, 12, 0.08);
  transform: translateY(-3px);
}

.feature-card__icon-wrap {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-lg);
  background: var(--color-primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-5);
}

.feature-card__icon {
  width: 28px;
  height: 28px;
  color: var(--color-primary);
}

.feature-card__title {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-3);
  letter-spacing: -0.01em;
}

.feature-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* Deterministic grading highlight */
.grading-highlight {
  background: var(--color-text);
  border-radius: var(--radius-xl);
  padding: var(--space-10) var(--space-12);
}

.grading-highlight__inner {
  display: flex;
  gap: var(--space-8);
  align-items: flex-start;
}

@media (max-width: 640px) {
  .grading-highlight__inner {
    flex-direction: column;
  }
}

.grading-highlight__icon {
  flex-shrink: 0;
  color: var(--color-primary);
  margin-top: 4px;
}

.grading-highlight__title {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: var(--space-3);
  letter-spacing: -0.02em;
}

.grading-highlight__desc {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.65);
  line-height: 1.7;
}

.grading-highlight__desc code {
  color: var(--color-primary);
  font-size: 0.875em;
}

/* How It Works Section
   ========================================================================== */
.how-it-works__title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  text-align: center;
}

.how-it-works__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-16);
  text-align: center;
}

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-8);
  margin-bottom: var(--space-16);
}

.step {
  text-align: center;
  padding: var(--space-8);
  position: relative;
}

.step__number {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: white;
  font-size: var(--text-xl);
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-6);
  box-shadow: 0 8px 24px rgba(234, 88, 12, 0.3);
}

.step__title {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.step__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
}

.step__code {
  display: inline-block;
  padding: var(--space-2) var(--space-4);
  background: var(--color-terminal-bg);
  color: var(--color-primary);
  border-radius: var(--radius-md);
  font-size: 0.8rem;
  font-family: var(--font-mono);
}

/* Config Tabs */
.config-tabs {
  background: var(--color-white);
  border-radius: var(--radius-xl);
  border: 1.5px solid var(--color-border);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.config-tabs__header {
  display: flex;
  border-bottom: 1px solid var(--color-border);
  overflow-x: auto;
}

.config-tab {
  padding: var(--space-4) var(--space-6);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  border-bottom: 2px solid transparent;
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.config-tab:hover {
  color: var(--color-primary);
}

.config-tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.config-panel {
  display: none;
  padding: var(--space-6);
}

.config-panel.active {
  display: block;
}

.config-panel__path {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
  padding: var(--space-2) var(--space-3);
  background: var(--color-background);
  border-radius: var(--radius-sm);
}

.config-code {
  background: var(--color-terminal-bg);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  overflow-x: auto;
}

.config-code code {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.6;
}

/* Domains Section
   ========================================================================== */
.domains__title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  text-align: center;
}

.domains__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-16);
  text-align: center;
}

.domains__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-6);
}

.domain-card {
  padding: var(--space-8) var(--space-10);
  background: var(--color-white);
  border-radius: var(--radius-xl);
  border: 1.5px solid var(--color-border);
  transition: all var(--transition-base);
}

.domain-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 8px 32px rgba(234, 88, 12, 0.08);
  transform: translateY(-2px);
}

.domain-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
}

.domain-num {
  font-size: var(--text-sm);
  font-weight: 800;
  color: var(--color-primary);
  font-family: var(--font-mono);
}

.domain-weight {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text-muted);
}

.domain-card__title {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
  letter-spacing: -0.01em;
  line-height: 1.3;
}

.domain-card__tasks {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
  margin-bottom: var(--space-5);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.domain-card__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.domain-card__list li {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  padding-left: 1rem;
  position: relative;
  line-height: 1.5;
}

.domain-card__list li::before {
  content: '·';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 700;
}

/* Study Modes Section
   ========================================================================== */
.modes__title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  text-align: center;
}

.modes__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-16);
  text-align: center;
}

.modes__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-6);
}

.mode-card {
  padding: var(--space-8);
  background: var(--color-background);
  border-radius: var(--radius-xl);
  border: 1.5px solid var(--color-border);
  transition: all var(--transition-base);
}

.mode-card:hover {
  border-color: var(--color-primary);
  background: var(--color-white);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.mode-card__num {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-primary);
  opacity: 0.15;
  font-family: var(--font-mono);
  line-height: 1;
  margin-bottom: var(--space-4);
}

.mode-card:hover .mode-card__num {
  opacity: 0.4;
}

.mode-card__title {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-3);
  letter-spacing: -0.01em;
}

.mode-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-5);
}

.mode-card__prompt {
  display: inline-block;
  padding: var(--space-2) var(--space-4);
  background: var(--color-terminal-bg);
  color: rgba(255, 255, 255, 0.7);
  border-radius: var(--radius-md);
  font-size: 0.8rem;
  font-family: var(--font-mono);
}

/* Local / Privacy Section
   ========================================================================== */
.local-section {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
  width: 100%;
}

.local-section__icon {
  width: 64px;
  height: 64px;
  color: var(--color-primary);
  margin: 0 auto var(--space-6);
}

.local-section__title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.local-section__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-10);
}

.local-section__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  text-align: left;
  max-width: 480px;
  margin: 0 auto;
}

.local-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.local-item__check {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  color: var(--color-success);
  margin-top: 2px;
}

.local-item code {
  font-size: 0.85em;
  color: var(--color-primary);
}

/* CTA Section
   ========================================================================== */
.cta {
  background: linear-gradient(135deg, var(--color-text) 0%, #1E293B 100%);
  min-height: 60vh;
}

.cta__title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  color: var(--color-white);
  text-align: center;
  margin-bottom: var(--space-4);
  letter-spacing: -0.03em;
}

.cta__subtitle {
  font-size: var(--text-lg);
  color: rgba(255, 255, 255, 0.6);
  text-align: center;
  margin-bottom: var(--space-10);
}

.cta__install {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  background: rgba(255, 255, 255, 0.06);
  border: 1.5px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-xl);
  padding: var(--space-4) var(--space-6);
  max-width: 520px;
  margin: 0 auto var(--space-8);
}

.cta__code {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.85);
  flex: 1;
}

.cta__copy {
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
  flex-shrink: 0;
}

.cta__copy:hover {
  color: var(--color-primary);
}

.cta__links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-8);
  flex-wrap: wrap;
}

.cta__link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 500;
  color: rgba(255, 255, 255, 0.5);
  transition: color var(--transition-fast);
}

.cta__link:hover {
  color: var(--color-primary);
}

/* FAQ Section
   ========================================================================== */
.section--faq {
  min-height: auto;
}

.faq {
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

.faq__title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  text-align: center;
}

.faq__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-12);
  text-align: center;
}

.faq__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
  gap: var(--space-6);
}

@media (max-width: 640px) {
  .faq__grid {
    grid-template-columns: 1fr;
  }
}

.faq__item {
  padding: var(--space-8) var(--space-10);
  background: var(--color-background);
  border-radius: var(--radius-xl);
  border: 1.5px solid var(--color-border);
}

.faq__question {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-3);
  letter-spacing: -0.01em;
}

.faq__answer {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.faq__answer code {
  font-size: 0.85em;
  color: var(--color-primary);
}

/* Footer
   ========================================================================== */
.footer {
  background: var(--color-text);
  padding: var(--space-8) 0;
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-8);
  flex-wrap: wrap;
}

.footer__logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: rgba(255, 255, 255, 0.6);
}

.footer__logo .logo__text {
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.875rem;
}

.footer__logo:hover .logo__text,
.footer__logo:hover svg {
  color: var(--color-primary);
}

.footer__text {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.4);
}

.footer__text a {
  color: rgba(255, 255, 255, 0.6);
  transition: color var(--transition-fast);
}

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

.footer__links {
  display: flex;
  gap: var(--space-6);
}

.footer__link {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.4);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-primary);
}

/* Toast
   ========================================================================== */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--color-text);
  color: var(--color-white);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 500;
  box-shadow: var(--shadow-xl);
  transition: transform var(--transition-base);
  z-index: 200;
  pointer-events: none;
}

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

/* Responsive
   ========================================================================== */
@media (max-width: 768px) {
  :root {
    --section-padding: 70px;
  }

  .header__nav {
    gap: var(--space-4);
  }

  .header__link {
    display: none;
  }

  .hero__stats {
    gap: var(--space-4);
  }

  .hero__card-demo {
    max-width: 100%;
  }

  .hero__badge-float--sm2 {
    top: -16px;
    right: 8px;
  }

  .hero__badge-float--grading {
    bottom: -16px;
    left: 8px;
  }

  .grading-highlight {
    padding: var(--space-8);
  }

  .footer__inner {
    flex-direction: column;
    text-align: center;
  }

  .footer__links {
    flex-wrap: wrap;
    justify-content: center;
  }

  .cta__install {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero__buttons {
    flex-direction: column;
  }

  .btn {
    justify-content: center;
  }

  .features__grid,
  .domains__grid,
  .modes__grid {
    grid-template-columns: 1fr;
  }

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