/* ============================================================================
 * Collavre Landing Page
 * Uses design tokens exclusively — no hardcoded colors.
 * Primary accent: --color-active (the blue used throughout the app UI)
 *
 * Typography scale (4 levels only):
 *   L1  --text-7                     Hero title, CTA title
 *   L2  --text-5                     Section titles, tagline
 *   L3  --text-3                     Card titles, subtitles, button-lg
 *   L4  --text-2                     Body copy, descriptions, buttons, footer
 * ============================================================================ */

/* ─── Reset & Base ──────────────────────────────────────────────────────────── */
.landing-page {
  overflow-x: hidden;
  scroll-behavior: smooth;
}

.landing-page nav {
  display: none; /* hide app navigation */
}

.landing {
  font-family: var(--font-sans);
  color: var(--text-primary);
  line-height: var(--leading-2);
}

/* Container: sets the content boundary */
.landing-container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 var(--space-5);
}

/* ─── Buttons ───────────────────────────────────────────────────────────────── */
.landing-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-2) var(--space-5);
  border-radius: var(--radius-3);
  font-weight: var(--weight-6);
  font-size: var(--text-2);             /* L4 */
  text-decoration: none;
  transition: all 0.2s var(--ease-2);
  background: var(--color-active);
  color: white;
  border: none;
  cursor: pointer;
}

.landing-btn:hover {
  filter: brightness(1.1);
  transform: translateY(-1px);
  box-shadow: var(--shadow-2);
}

.landing-btn-lg {
  padding: var(--space-3) var(--space-7);
  font-size: var(--text-3);             /* L3 */
  border-radius: var(--radius-4);
}

.landing-btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border: var(--border-1) solid var(--border-color);
}

.landing-btn-ghost:hover {
  color: var(--text-primary);
  border-color: var(--text-muted);
  background: var(--surface-hover);
  filter: none;
}

/* ─── Hero ──────────────────────────────────────────────────────────────────── */
.landing-hero {
  position: relative;
  padding: var(--space-10) 0 var(--space-8);
  text-align: center;
}

.landing-hero-glow {
  position: absolute;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, color-mix(in srgb, var(--color-active) 12%, transparent) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.landing-hero-title {                   /* L1 — main headline */
  font-size: var(--text-7);
  font-weight: var(--weight-8);
  letter-spacing: 0.02em;
  line-height: var(--leading-1);
  color: var(--text-primary);
  margin: 0 auto var(--space-5);
  max-width: 900px;
  position: relative;
  z-index: 1;
}

.landing-hero-sub {                     /* L3 — subline */
  font-size: var(--text-3);
  font-weight: var(--weight-6);
  color: var(--text-muted);
  margin: 0 auto var(--space-5);
  max-width: 900px;
  text-align: center;
  position: relative;
  z-index: 1;
}

.landing-hero-brand {                   /* L1 — "콜라브" in brand color */
  font-size: var(--text-7);
  font-weight: var(--weight-8);
  letter-spacing: 0.02em;
  color: var(--color-active);
  margin: 0 auto var(--space-7);
  text-align: center;
  position: relative;
  z-index: 1;
}

.landing-hero-actions {
  display: flex;
  gap: var(--space-3);
  justify-content: center;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}

/* ─── Demo Section ──────────────────────────────────────────────────────────── */

.landing-demo-frame {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-4);
  border: var(--border-1) solid var(--border-color);
  background: var(--surface-section);
  overflow: hidden;
  box-shadow: var(--shadow-3);
}

.landing-demo-video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* ─── Demo: Progress bar ──────────────────────────────────────────────────── */
.landing-demo-progress {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: color-mix(in srgb, var(--text-primary) 15%, transparent);
  z-index: 2;
}

.landing-demo-progress-fill {
  height: 100%;
  width: 0;
  background: var(--color-active);
  transition: width 0.1s linear;
}

/* ─── Demo: Play/Pause toggle ─────────────────────────────────────────────── */
.landing-demo-toggle {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.25s ease;
  z-index: 1;
}

.landing-demo-frame:hover .landing-demo-toggle {
  opacity: 1;
  background: color-mix(in srgb, var(--bg-primary) 40%, transparent);
}

.landing-demo-toggle-icon {
  font-size: var(--text-5);             /* L2 */
  color: var(--text-primary);
  background: color-mix(in srgb, var(--bg-primary) 80%, transparent);
  width: 56px;
  height: 56px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
  box-shadow: var(--shadow-2);
}

/* ─── Sections (shared) ─────────────────────────────────────────────────────── */
.landing-section {
  padding: var(--space-10) 0;
}

.landing-section-title {                /* L2 */
  font-size: var(--text-5);
  font-weight: var(--weight-7);
  text-align: center;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-3);
}

.landing-section-sub {                  /* L4 */
  font-size: var(--text-2);
  color: var(--text-muted);
  text-align: center;
  max-width: 560px;
  margin: 0 auto var(--space-8);
}

/* ─── Problem Section ───────────────────────────────────────────────────────── */
.landing-problem {
  background: var(--surface-section);
}

.landing-problem-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-5);
  max-width: 900px;
  margin: var(--space-7) auto 0;
}

.landing-problem-card {
  padding: var(--space-5);
  border-radius: var(--radius-3);
  border: var(--border-1) solid var(--border-color);
  background: var(--surface-bg);
  transition: border-color 0.2s var(--ease-2);
}

.landing-problem-card:hover {
  border-color: var(--text-muted);
}

.landing-problem-icon {
  font-size: var(--text-5);             /* L2 — emoji decorative */
  display: block;
  margin-bottom: var(--space-3);
}

.landing-problem-card h3 {             /* L3 */
  font-size: var(--text-3);
  font-weight: var(--weight-6);
  margin-bottom: var(--space-2);
}

.landing-problem-card p {              /* L4 */
  font-size: var(--text-2);
  color: var(--text-muted);
  line-height: var(--leading-2);
}

/* ─── Features Grid ─────────────────────────────────────────────────────────── */
.landing-features {
  background: var(--surface-bg);
}

.landing-features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-5);
}

.landing-feature-card {
  padding: var(--space-5);
  border-radius: var(--radius-3);
  border: var(--border-1) solid var(--border-color);
  background: var(--surface-section);
  transition: all 0.25s var(--ease-2);
}

.landing-feature-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
  border-color: var(--color-active);
}

.landing-feature-icon {
  font-size: var(--text-5);             /* L2 — emoji decorative */
  margin-bottom: var(--space-3);
}

.landing-feature-card h3 {             /* L3 */
  font-size: var(--text-3);
  font-weight: var(--weight-6);
  margin-bottom: var(--space-2);
}

.landing-feature-card p {              /* L4 */
  font-size: var(--text-2);
  color: var(--text-muted);
  line-height: var(--leading-2);
}

/* ─── How It Works ──────────────────────────────────────────────────────────── */
.landing-how {
  background: var(--surface-section);
}

.landing-steps {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: var(--space-3);
  flex-wrap: wrap;
  max-width: 900px;
  margin: var(--space-7) auto 0;
}

.landing-step {
  flex: 1;
  min-width: 200px;
  max-width: 260px;
  text-align: center;
}

.landing-step-num {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-round);
  background: var(--color-active);
  color: white;
  font-size: var(--text-3);             /* L3 */
  font-weight: var(--weight-7);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-3);
}

.landing-step h3 {                     /* L3 */
  font-size: var(--text-3);
  font-weight: var(--weight-6);
  margin-bottom: var(--space-2);
}

.landing-step p {                      /* L4 */
  font-size: var(--text-2);
  color: var(--text-muted);
  line-height: var(--leading-2);
}

.landing-step-arrow {
  font-size: var(--text-5);             /* L2 */
  color: var(--text-muted);
  padding-top: var(--space-3);
  user-select: none;
}

/* ─── CTA Section ───────────────────────────────────────────────────────────── */
.landing-cta {
  text-align: center;
  padding: var(--space-11) 0;
  background: var(--surface-bg);
}

.landing-cta-title {                    /* L1 */
  font-size: var(--text-7);
  font-weight: var(--weight-8);
  letter-spacing: 0.02em;
  margin-bottom: var(--space-3);
}

.landing-cta-sub {                     /* L4 */
  font-size: var(--text-2);
  color: var(--text-muted);
  margin-bottom: var(--space-7);
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

/* ─── Footer (center-aligned) ───────────────────────────────────────────────── */
.landing-footer {
  border-top: var(--border-1) solid var(--border-color);
  padding: var(--space-5) 0;
}

.landing-footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  text-align: center;
}

.landing-footer-brand {                /* L4 */
  font-weight: var(--weight-6);
  font-size: var(--text-2);
  color: var(--text-primary);
}

.landing-footer-copy {                 /* L4 */
  font-size: var(--text-2);
  color: var(--text-muted);
}

/* ─── Demo: Theme-aware video switching ────────────────────────────────────── */
.landing-demo-dark { display: none; }

body.dark-mode .landing-demo-light { display: none; }
body.dark-mode .landing-demo-dark { display: block; }

@media (prefers-color-scheme: dark) {
  body:not(.light-mode) .landing-demo-light { display: none; }
  body:not(.light-mode) .landing-demo-dark { display: block; }
}

/* ─── Responsive ────────────────────────────────────────────────────────────── */
@media (max-width: 640px) {
  .landing-container {
    padding: 0 var(--space-3);
  }

  .landing-hero {
    padding: var(--space-9) 0 var(--space-7);
  }

  .landing-hero-title {                  /* L1 scaled down on mobile */
    font-size: var(--text-5);
  }

  .landing-hero-brand {                 /* L1 scaled down on mobile */
    font-size: var(--text-5);
  }

  .landing-hero-glow {
    width: 350px;
    height: 350px;
  }

  .landing-section {
    padding: var(--space-8) 0;
  }

  .landing-steps {
    flex-direction: column;
    align-items: center;
  }

  .landing-step-arrow {
    transform: rotate(90deg);
    padding: 0;
  }

  .landing-step {
    max-width: 100%;
  }

  .landing-features-grid {
    grid-template-columns: 1fr;
  }

  .landing-cta-title {                  /* L1 scaled down on mobile */
    font-size: var(--text-5);
  }
}

/* ─── Entrance animations ───────────────────────────────────────────────────── */
@keyframes landing-fade-up {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.landing-hero-title,
.landing-hero-sub,
.landing-hero-brand,
.landing-hero-actions {
  animation: landing-fade-up 0.6s var(--ease-out-3) both;
}

.landing-hero-title { animation-delay: 0s; }
.landing-hero-sub { animation-delay: 0.1s; }
.landing-hero-brand { animation-delay: 0.2s; }
.landing-hero-actions { animation-delay: 0.3s; }