/* ============================================
   AI YHCT Landing Page — Styles
   Design: "Serenity AI" — Spa + AI Fusion
   Mobile-first: iPhone SE (320px) → Desktop
   ============================================ */

/* === DESIGN TOKENS === */
:root {
  /* Background */
  --bg: #0D1F1C;
  --bg-card: #132A26;
  --bg-elevated: #1A3530;
  --bg-glass: rgba(19, 42, 38, 0.85);

  /* Text */
  --text: #E8EDE6;
  --text-muted: #8FA399;
  --text-dim: #5E7A6E;

  /* Primary — Warm Gold */
  --primary: #C9A96E;
  --primary-light: #DFC08A;
  --primary-dark: #A88B4A;
  --primary-glow: rgba(201, 169, 110, 0.15);

  /* Accent — AI Teal */
  --accent: #4ECDC4;
  --accent-soft: rgba(78, 205, 196, 0.12);
  --accent-muted: rgba(78, 205, 196, 0.6);

  /* Semantic */
  --danger: #E74C3C;
  --danger-soft: rgba(231, 76, 60, 0.1);
  --success: #2ECC71;

  /* Borders & Shadows */
  --border: rgba(255, 255, 255, 0.06);
  --border-gold: rgba(201, 169, 110, 0.2);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.15);
  --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.2);
  --shadow-gold: 0 8px 30px rgba(201, 169, 110, 0.2);

  /* Geometry */
  --radius: 12px;
  --radius-lg: 16px;
  --radius-full: 50px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Be Vietnam Pro', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s;
}
a:hover { color: var(--primary-light); }

img { max-width: 100%; display: block; }
ul { list-style: none; }

/* === CONTAINER === */
.container {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 16px;
}
@media (min-width: 375px) {
  .container { padding: 0 20px; }
}
@media (min-width: 768px) {
  .container { padding: 0 32px; }
}

/* === BUTTONS === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: inherit;
  font-weight: 700;
  border: none;
  cursor: pointer;
  transition: all 0.25s ease;
  min-height: 48px;
  min-width: 44px;
  border-radius: var(--radius-full);
  text-align: center;
  line-height: 1.2;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: var(--bg);
  padding: 14px 28px;
  font-size: 0.95rem;
  box-shadow: var(--shadow-gold);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(201, 169, 110, 0.35);
  color: var(--bg);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  padding: 14px 28px;
  font-size: 0.95rem;
  border: 1.5px solid var(--border-gold);
}
.btn-outline:hover {
  background: var(--primary-glow);
  border-color: var(--primary);
  color: var(--primary-light);
}

.btn-full {
  width: 100%;
  justify-content: center;
  font-size: 1rem;
}

/* === NAVBAR === */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 10px 0;
  transition: all 0.3s ease;
}
.nav.scrolled {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 8px 0;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.nav-logo {
  font-weight: 800;
  font-size: 1rem;
  color: var(--primary);
  letter-spacing: -0.02em;
  white-space: nowrap;
}
.nav-logo span {
  color: var(--text-muted);
  font-weight: 400;
  font-size: 0.75rem;
}

.nav-cta {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: var(--bg);
  padding: 8px 16px;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.8rem;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  transition: all 0.2s;
  white-space: nowrap;
}
.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-gold);
  color: var(--bg);
}

/* === HERO === */
.hero {
  min-height: 100svh;
  display: flex;
  align-items: center;
  padding: 80px 0 48px;
  position: relative;
  overflow: hidden;
}

/* Ambient glow */
.hero::before {
  content: '';
  position: absolute;
  top: -30%;
  right: -20%;
  width: 60vw;
  height: 60vw;
  max-width: 500px;
  max-height: 500px;
  background: radial-gradient(circle, rgba(201, 169, 110, 0.08), transparent 70%);
  pointer-events: none;
}
.hero::after {
  content: '';
  position: absolute;
  bottom: -20%;
  left: -15%;
  width: 50vw;
  height: 50vw;
  max-width: 400px;
  max-height: 400px;
  background: radial-gradient(circle, rgba(78, 205, 196, 0.05), transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--accent-soft);
  border: 1px solid rgba(78, 205, 196, 0.2);
  border-radius: var(--radius-full);
  padding: 6px 14px;
  font-size: 0.75rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 20px;
  animation: fadeInUp 0.6s ease;
}

.hero-badge .dot {
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse 2s infinite;
  flex-shrink: 0;
}

.hero h1 {
  font-size: clamp(1.75rem, 7vw, 3.2rem);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
  animation: fadeInUp 0.6s ease 0.1s both;
}

.hero h1 .highlight {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: clamp(0.88rem, 2.5vw, 1.1rem);
  color: var(--text-muted);
  max-width: 560px;
  margin-bottom: 28px;
  line-height: 1.7;
  animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  animation: fadeInUp 0.6s ease 0.3s both;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  animation: fadeInUp 0.6s ease 0.4s both;
}

.hero-stat {
  text-align: center;
}

.hero-stat-num {
  font-size: clamp(1.4rem, 4vw, 2rem);
  font-weight: 800;
  color: var(--primary);
  line-height: 1.2;
}

.hero-stat-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: 2px;
  line-height: 1.3;
}

@media (min-width: 375px) {
  .hero-stat-label { font-size: 0.75rem; }
  .hero-stat-num { font-size: clamp(1.5rem, 4vw, 2rem); }
}

@media (min-width: 768px) {
  .hero-actions {
    flex-direction: row;
    gap: 16px;
  }
}

/* === SECTIONS === */
section {
  padding: 48px 0;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 12px;
}
.section-label::before {
  content: '';
  width: 20px;
  height: 1.5px;
  background: var(--accent);
  border-radius: 1px;
}

.section-title {
  font-size: clamp(1.4rem, 5vw, 2.4rem);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.section-desc {
  font-size: clamp(0.88rem, 2.5vw, 1rem);
  color: var(--text-muted);
  max-width: 600px;
  margin-bottom: 32px;
  line-height: 1.7;
}

@media (min-width: 768px) {
  section { padding: 80px 0; }
  .section-desc { margin-bottom: 48px; }
}

/* === PAIN SECTION === */
.pain {
  background: linear-gradient(180deg, var(--bg) 0%, var(--bg-card) 100%);
}

.pain-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.pain-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  transition: border-color 0.3s;
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.pain-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 0.85rem;
  font-weight: 700;
  background: var(--danger-soft);
  color: var(--danger);
}

.pain-content h3 {
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 4px;
  line-height: 1.3;
}

.pain-content p {
  color: var(--text-muted);
  font-size: 0.82rem;
  line-height: 1.55;
}

@media (min-width: 768px) {
  .pain-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  .pain-card { padding: 24px; }
}

/* === TRANSFORMATION === */
.transform-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.transform-col {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.transform-col h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.transform-item {
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.84rem;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  line-height: 1.5;
}
.transform-item:last-child { border-bottom: none; }

.transform-item .icon {
  flex-shrink: 0;
  margin-top: 2px;
  font-weight: 700;
}

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

.transform-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-size: 1.2rem;
  padding: 4px 0;
}

@media (min-width: 768px) {
  .transform-grid {
    grid-template-columns: 1fr auto 1fr;
    gap: 24px;
    align-items: stretch;
  }
  .transform-arrow {
    font-size: 1.8rem;
    padding: 0;
    align-self: center;
  }
}

/* === FEATURES === */
.features {
  background: linear-gradient(180deg, var(--bg-card) 0%, var(--bg) 100%);
}

.feat-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.feat-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s;
}
.feat-card:hover {
  border-color: var(--border-gold);
}

.feat-num {
  font-size: 2rem;
  font-weight: 900;
  color: rgba(201, 169, 110, 0.08);
  position: absolute;
  top: 12px;
  right: 16px;
  line-height: 1;
}

.feat-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--primary-light);
  line-height: 1.3;
}

.feat-card p {
  color: var(--text-muted);
  font-size: 0.84rem;
  line-height: 1.6;
}

@media (min-width: 500px) {
  .feat-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 14px;
  }
}

@media (min-width: 768px) {
  .feat-grid { gap: 20px; }
  .feat-card { padding: 28px; }
}

/* === SOCIAL PROOF === */
.proof-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.proof-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.proof-quote {
  font-size: 0.88rem;
  font-style: italic;
  color: var(--text);
  margin-bottom: 16px;
  position: relative;
  padding-left: 16px;
  border-left: 2px solid var(--primary);
  line-height: 1.6;
}

.proof-author {
  display: flex;
  align-items: center;
  gap: 10px;
}

.proof-avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--bg);
  font-size: 0.8rem;
  flex-shrink: 0;
}

.proof-name {
  font-weight: 600;
  font-size: 0.85rem;
}

.proof-role {
  font-size: 0.75rem;
  color: var(--text-muted);
}

@media (min-width: 768px) {
  .proof-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }
}

/* === PRICING === */
.pricing {
  background: var(--bg-card);
  position: relative;
  overflow: hidden;
}
.pricing::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 100vw;
  height: 100vw;
  max-width: 700px;
  max-height: 700px;
  background: radial-gradient(circle, var(--primary-glow), transparent 60%);
  pointer-events: none;
}

.price-box {
  max-width: 580px;
  margin: 0 auto;
  background: var(--bg-elevated);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  text-align: center;
  position: relative;
}

.price-badge {
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: var(--bg);
  padding: 5px 18px;
  border-radius: var(--radius-full);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.price-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 4px;
  margin-top: 8px;
}

.price-amount {
  font-size: clamp(2.2rem, 8vw, 3rem);
  font-weight: 900;
  color: var(--primary);
  line-height: 1.1;
}
.price-amount span {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--text-muted);
}

.price-note {
  color: var(--text-muted);
  font-size: 0.82rem;
  margin: 4px 0 20px;
}

.price-warning {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--danger-soft);
  border: 1px solid rgba(231, 76, 60, 0.15);
  border-radius: 8px;
  padding: 8px 14px;
  font-size: 0.8rem;
  color: #FCA5A5;
  margin-bottom: 20px;
}
.price-warning strong {
  margin: 0 2px;
}

/* Slots counter */
.slots-counter {
  background: var(--primary-glow);
  border: 1px solid rgba(201, 169, 110, 0.12);
  border-radius: var(--radius);
  padding: 16px;
  margin: 16px 0;
}

.slots-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.slots-label {
  font-weight: 600;
  color: var(--primary);
  font-size: 0.85rem;
}
.slots-num {
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--accent);
}

.slots-bar {
  height: 6px;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 3px;
  overflow: hidden;
  margin: 10px 0 6px;
}
.slots-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--danger));
  border-radius: 3px;
  transition: width 1s ease;
}

.slots-text {
  font-size: 0.78rem;
  color: var(--text-muted);
}
.slots-text strong {
  color: var(--primary);
}

/* Price features */
.price-features {
  text-align: left;
  margin: 20px 0;
}
.price-features li {
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.84rem;
  line-height: 1.45;
}
.price-features li:last-child { border-bottom: none; }

.check {
  color: var(--accent);
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 1px;
}

.price-guarantee {
  margin-top: 10px;
  font-size: 0.75rem;
  color: var(--text-dim);
}

@media (min-width: 375px) {
  .price-box { padding: 32px 24px; }
}

/* === FAQ === */
.faq-list {
  max-width: 680px;
}

.faq-item {
  border-bottom: 1px solid var(--border);
}

.faq-q {
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 16px 0;
  min-height: 44px;
  user-select: none;
  -webkit-user-select: none;
  line-height: 1.4;
}

.faq-q::after {
  content: '+';
  font-size: 1.3rem;
  color: var(--primary);
  transition: transform 0.3s;
  flex-shrink: 0;
  width: 24px;
  text-align: center;
}

.faq-item.open .faq-q::after {
  transform: rotate(45deg);
}

.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease;
}

.faq-a-inner {
  padding: 0 0 16px;
  color: var(--text-muted);
  font-size: 0.86rem;
  line-height: 1.65;
}

/* === FINAL CTA === */
.final-cta {
  text-align: center;
  padding: 48px 0;
  position: relative;
}

.final-cta h2 {
  font-size: clamp(1.4rem, 5vw, 2.2rem);
  font-weight: 800;
  margin-bottom: 12px;
  line-height: 1.2;
}

.final-cta p {
  color: var(--text-muted);
  font-size: clamp(0.88rem, 2.5vw, 1rem);
  max-width: 500px;
  margin: 0 auto 24px;
  line-height: 1.65;
}

@media (min-width: 768px) {
  .final-cta { padding: 80px 0; }
}

/* === FOOTER === */
footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 32px 0 24px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.footer-brand {
  font-weight: 800;
  font-size: 1rem;
  color: var(--primary);
  margin-bottom: 8px;
}

.footer-desc {
  color: var(--text-muted);
  font-size: 0.82rem;
  line-height: 1.6;
  margin-bottom: 8px;
}

.footer-col h4 {
  font-weight: 600;
  font-size: 0.85rem;
  margin-bottom: 10px;
  color: var(--text);
}

.footer-col a {
  display: block;
  color: var(--text-muted);
  font-size: 0.82rem;
  padding: 3px 0;
  transition: color 0.2s;
}
.footer-col a:hover { color: var(--primary); }

.footer-bottom {
  border-top: 1px solid var(--border);
  margin-top: 20px;
  padding-top: 16px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px;
  font-size: 0.72rem;
  color: var(--text-dim);
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
  }
  footer { padding: 40px 0 28px; }
}

/* === ANIMATIONS === */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* Scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}

/* === UTILITY === */
.text-center { text-align: center; }
.text-gold { color: var(--primary); }
.text-accent { color: var(--accent); }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}