/* ============================================
   ClassGenie — Landing Page Styles
   ============================================ */

/* ---------- Custom Properties ---------- */
:root {
  --color-bg: #1C1C1C;
  --color-surface: #2C2C2C;
  --color-surface-alt: #333333;
  --color-text: #E3E0E2;
  --color-text-secondary: #A8A4A6;
  --color-accent: #EF9336;
  --color-accent-dim: rgba(239, 147, 54, 0.15);
  --color-highlight: #FFC066;
  --color-highlight-dim: rgba(255, 192, 102, 0.15);

  --font-stack: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', monospace;

  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2.5rem;
  --spacing-xl: 4rem;
  --spacing-2xl: 6rem;

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

  --navbar-height: 64px;
  --max-width: 1120px;

  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
}

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

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

body {
  font-family: var(--font-stack);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

ul {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

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

.text-accent {
  color: var(--color-accent);
}

.text-highlight {
  color: var(--color-highlight);
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  text-align: center;
  margin-bottom: var(--spacing-xl);
  line-height: 1.2;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 2rem;
  border-radius: var(--radius-full);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  border: none;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.btn--primary {
  background: var(--color-accent);
  color: #1C1C1C;
  box-shadow: 0 4px 20px rgba(239, 147, 54, 0.3);
}

.btn--primary:hover {
  box-shadow: 0 6px 28px rgba(239, 147, 54, 0.45);
}

.btn--highlight {
  background: var(--color-highlight);
  color: #1C1C1C;
  box-shadow: 0 4px 20px rgba(255, 192, 102, 0.3);
}

.btn--highlight:hover {
  box-shadow: 0 6px 28px rgba(255, 192, 102, 0.45);
}

.btn--large {
  padding: 1rem 2.5rem;
  font-size: 1.125rem;
}

.app-store-badge img {
  height: 44px;
  width: auto;
  transition: opacity var(--transition-fast);
}

.app-store-badge:hover img {
  opacity: 0.85;
}

/* ---------- Fade-in Animation ---------- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

/* ---------- Phone Mockup (Placeholder) ---------- */
.phone-mockup {
  width: 260px;
  border-radius: 36px;
  border: 3px solid var(--color-surface-alt);
  background: var(--color-surface);
  padding: 12px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
  position: relative;
}

.phone-mockup--small {
  width: 200px;
}

.phone-mockup__screen {
  border-radius: 24px;
  overflow: hidden;
  aspect-ratio: 9 / 19.5;
  background: linear-gradient(160deg, #2C2C2C 0%, #1C1C1C 100%);
}

.phone-mockup__placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: var(--spacing-md);
  text-align: center;
  gap: var(--spacing-sm);
}

.phone-mockup__placeholder p {
  font-size: 0.95rem;
  font-family: var(--font-mono);
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.phone-mockup__placeholder small {
  font-size: 0.75rem;
  color: var(--color-accent);
  opacity: 0.9;
  text-align: left;
  width: 100%;
}

.phone-mockup__icon {
  font-size: 2rem;
  color: var(--color-accent);
}

.phone-mockup__placeholder--step {
  gap: var(--spacing-xs);
}

.phone-mockup__placeholder--step span {
  font-size: 2.5rem;
}

.phone-mockup__placeholder--step p {
  font-size: 0.85rem;
  font-family: var(--font-stack);
}


/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--navbar-height);
  z-index: 1000;
  background: rgba(28, 28, 28, 0.8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-base), background var(--transition-base);
}

.navbar.is-scrolled {
  border-bottom-color: var(--color-surface-alt);
  background: rgba(28, 28, 28, 0.95);
}

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

.navbar__brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  z-index: 10;
}

.navbar__icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  flex-shrink: 0;
}

.navbar__wordmark {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.navbar__links {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.navbar__links a {
  font-size: 0.925rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

.navbar__links a:hover {
  color: var(--color-text);
}

.navbar__cta {
  background: var(--color-accent);
  color: #fff !important;
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-full);
  font-weight: 600 !important;
}

.navbar__cta:hover {
  opacity: 0.9;
}

/* Hamburger */
.navbar__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  z-index: 10;
}

.navbar__hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.navbar__hamburger.is-active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.navbar__hamburger.is-active span:nth-child(2) {
  opacity: 0;
}

.navbar__hamburger.is-active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ============================================
   HERO
   ============================================ */
.hero {
  padding-top: calc(var(--navbar-height) + var(--spacing-2xl));
  padding-bottom: var(--spacing-2xl);
  min-height: 100vh;
  display: flex;
  align-items: center;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: var(--spacing-xl);
}

.hero__title {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: var(--spacing-md);
}

.hero__subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  max-width: 460px;
}

.hero__actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.hero__visual {
  display: flex;
  justify-content: center;
}

/* ============================================
   FEATURES
   ============================================ */
.features {
  padding: var(--spacing-2xl) 0;
}

.features__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}

.feature-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  text-align: center;
  border: 1px solid transparent;
  transition: border-color var(--transition-base), transform var(--transition-base);
}

.feature-card:hover {
  border-color: var(--color-surface-alt);
  transform: translateY(-4px);
}

.feature-card__icon {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-sm);
}

.feature-card__title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
}

.feature-card__desc {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* ============================================
   HOW IT WORKS
   ============================================ */
.how-it-works {
  padding: var(--spacing-2xl) 0;
  background: var(--color-surface);
}

.screenshots {
  display: flex;
  gap: var(--spacing-md);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding-bottom: var(--spacing-sm);
  scrollbar-width: none;
  scroll-behavior: auto;
}

.screenshots::-webkit-scrollbar {
  display: none;
}

.screenshot {
  flex: 0 0 auto;
  width: 220px;
}

.screenshot img {
  width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
  display: block;
}

/* ============================================
   SUBJECTS
   ============================================ */
.subjects {
  padding: var(--spacing-2xl) 0;
}

.section-subtitle {
  text-align: center;
  color: var(--color-text-secondary);
  font-size: 1.05rem;
  max-width: 540px;
  margin: calc(-1 * var(--spacing-lg)) auto var(--spacing-xl);
  line-height: 1.5;
}

.subjects__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}

.subject-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  border: 1px solid var(--color-surface-alt);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  transition: border-color var(--transition-base), transform var(--transition-base);
}

.subject-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
}

.subject-card__icon {
  font-size: 2rem;
  margin-bottom: var(--spacing-xs);
}

.subject-card__title {
  font-size: 1.1rem;
  font-weight: 700;
}

.subject-card__desc {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  flex: 1;
}

.subject-card__tag {
  display: inline-block;
  align-self: flex-start;
  background: var(--color-accent-dim);
  color: var(--color-accent);
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: var(--spacing-xs);
}

/* ============================================
   FINAL CTA
   ============================================ */
.cta {
  padding: var(--spacing-2xl) 0;
  text-align: center;
}

.cta__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-md);
}

.cta__icon {
  width: 80px;
  height: 80px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.cta__title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  line-height: 1.15;
}

.cta__subtitle {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  max-width: 400px;
}

.cta__actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
  justify-content: center;
  margin-top: var(--spacing-sm);
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  padding: var(--spacing-lg) 0;
  border-top: 1px solid var(--color-surface-alt);
}

.footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
}

.footer__links {
  display: flex;
  gap: var(--spacing-lg);
  flex-wrap: wrap;
  justify-content: center;
}

.footer__links a {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

.footer__links a:hover {
  color: var(--color-text);
}

.footer__copy {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  opacity: 0.7;
}

/* ============================================
   RESPONSIVE — Tablet (768px)
   ============================================ */
@media (max-width: 768px) {
  .navbar__hamburger {
    display: flex;
  }

  .navbar__links {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(28, 28, 28, 0.98);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    flex-direction: column;
    justify-content: center;
    gap: var(--spacing-lg);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
  }

  .navbar__links.is-open {
    opacity: 1;
    pointer-events: auto;
  }

  .navbar__links a {
    font-size: 1.5rem;
  }

  .navbar__cta {
    font-size: 1.25rem !important;
    padding: 0.75rem 2rem;
  }

  .hero {
    min-height: auto;
    padding-top: calc(var(--navbar-height) + var(--spacing-xl));
    padding-bottom: var(--spacing-xl);
  }

  .hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero__subtitle {
    margin-left: auto;
    margin-right: auto;
  }

  .hero__actions {
    justify-content: center;
  }

  .hero__visual {
    order: -1;
  }

  .hero__visual .phone-mockup {
    width: 220px;
  }

  .features__grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }

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

/* ============================================
   RESPONSIVE — Small Mobile (480px)
   ============================================ */
@media (max-width: 480px) {
  .subjects__grid {
    grid-template-columns: 1fr;
  }

  .hero__actions {
    flex-direction: column;
  }

  .cta__actions {
    flex-direction: column;
  }

  .footer__links {
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
  }
}

/* ============================================
   RESPONSIVE — Desktop (1024px+)
   ============================================ */
@media (min-width: 1024px) {
  .features__grid {
    gap: var(--spacing-lg);
  }

  .feature-card {
    padding: var(--spacing-xl);
  }

  .subjects__grid {
    gap: var(--spacing-lg);
  }
}