/* ===== Couple Bridge — Landing Page Styles ===== */

:root {
  --primary: #0A7E8C;
  --primary-dark: #066570;
  --primary-light: #0A7E8C1a;
  --secondary: #FF7B6B;
  --secondary-light: #FF7B6B1a;
  --timeline: #FF6B6B;
  --crises: #FFA726;
  --attachment: #AB47BC;
  --dimensions: #42A5F5;
  --bg: #FAFBFC;
  --bg-white: #FFFFFF;
  --bg-section: #F4F6F8;
  --text: #1A2332;
  --text-secondary: #5A6B7F;
  --text-muted: #8B99AB;
  --border: #E2E8F0;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow: 0 4px 20px rgba(0,0,0,0.06);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.1);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 1140px;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

ul, ol { list-style: none; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

.nav.scrolled {
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
}

.nav-brand svg {
  width: 32px;
  height: 32px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition);
}

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

.lang-toggle {
  display: flex;
  align-items: center;
  background: var(--bg-section);
  border-radius: 20px;
  padding: 3px;
  gap: 2px;
  cursor: pointer;
  border: 1px solid var(--border);
}

.lang-btn {
  border: none;
  background: transparent;
  font-size: 0.82rem;
  font-weight: 600;
  padding: 5px 12px;
  border-radius: 17px;
  cursor: pointer;
  color: var(--text-muted);
  transition: all var(--transition);
  font-family: inherit;
}

.lang-btn.active {
  background: var(--bg-white);
  color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--text);
}

.mobile-menu-btn svg {
  width: 24px;
  height: 24px;
}

/* ===== Hero ===== */
.hero {
  padding: 140px 0 80px;
  text-align: center;
  background: linear-gradient(180deg, #f0fafb 0%, var(--bg) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  width: 500px; height: 500px;
  background: radial-gradient(circle, var(--primary-light) 0%, transparent 70%);
  top: -100px; left: 50%;
  transform: translateX(-50%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 8px 18px;
  border-radius: 24px;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.hero h1 .accent {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: inherit;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 14px 28px;
  border-radius: 14px;
  border: none;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 4px 14px rgba(10,126,140,0.3);
}
.btn-primary:hover {
  background: var(--primary-dark);
  box-shadow: 0 6px 20px rgba(10,126,140,0.4);
  transform: translateY(-1px);
  color: #fff;
}

.btn-outline {
  background: var(--bg-white);
  color: var(--text);
  border: 1.5px solid var(--border);
}
.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-1px);
}

.btn svg { width: 20px; height: 20px; }

.hero-platforms {
  margin-top: 24px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ===== Features ===== */
.features {
  padding: 100px 0;
}

.section-label {
  text-align: center;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--primary);
  margin-bottom: 12px;
}

.section-title {
  text-align: center;
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.section-sub {
  text-align: center;
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 56px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.feature-card {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card:hover {
  border-color: transparent;
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
}

.feature-card.timeline::before { background: var(--timeline); }
.feature-card.crises::before { background: var(--crises); }
.feature-card.attachment::before { background: var(--attachment); }
.feature-card.dimensions::before { background: var(--dimensions); }

.feature-icon {
  width: 52px; height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.5rem;
}

.feature-card.timeline .feature-icon { background: #FF6B6B18; color: var(--timeline); }
.feature-card.crises .feature-icon { background: #FFA72618; color: var(--crises); }
.feature-card.attachment .feature-icon { background: #AB47BC18; color: var(--attachment); }
.feature-card.dimensions .feature-icon { background: #42A5F518; color: var(--dimensions); }

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.feature-stats {
  display: flex;
  gap: 20px;
  margin-top: 18px;
}

.feature-stat {
  font-size: 0.82rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 5px;
}

.feature-stat strong {
  color: var(--text);
  font-weight: 700;
}

/* ===== Extra features row ===== */
.extras {
  padding: 0 0 100px;
}

.extras-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.extra-card {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  transition: all var(--transition);
}

.extra-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.extra-icon {
  width: 48px; height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 1.3rem;
  background: var(--primary-light);
  color: var(--primary);
}

.extra-card h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.extra-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===== Science / About ===== */
.science {
  padding: 100px 0;
  background: var(--bg-section);
}

.science-intro {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 56px;
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

.researchers-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 48px;
}

.researcher-card {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: all var(--transition);
}

.researcher-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.researcher-card h4 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
}

.researcher-card .role {
  font-size: 0.82rem;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 12px;
}

.researcher-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

.researcher-card .evidence {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
  font-size: 0.82rem;
  color: var(--text-muted);
  font-style: italic;
}

.books-section {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
}

.books-section h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 20px;
  text-align: center;
}

.books-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 14px;
}

.book-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--bg-section);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  line-height: 1.5;
}

.book-item .book-icon {
  flex-shrink: 0;
  font-size: 1.2rem;
}

.book-item strong {
  color: var(--text);
}

.book-item span {
  color: var(--text-secondary);
}

/* ===== FAQ ===== */
.faq {
  padding: 100px 0;
}

.faq-grid {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: all var(--transition);
}

.faq-item:hover {
  border-color: var(--primary);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  cursor: pointer;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  text-align: left;
  gap: 12px;
}

.faq-question svg {
  width: 20px; height: 20px;
  flex-shrink: 0;
  color: var(--text-muted);
  transition: transform var(--transition);
}

.faq-item.open .faq-question svg {
  transform: rotate(45deg);
}

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

.faq-answer-inner {
  padding: 0 24px 20px;
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== CTA ===== */
.cta {
  padding: 100px 0;
  background: linear-gradient(135deg, var(--primary) 0%, #0B97A8 100%);
  text-align: center;
  color: #fff;
}

.cta h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.cta p {
  font-size: 1.1rem;
  opacity: 0.85;
  max-width: 500px;
  margin: 0 auto 36px;
}

.cta .btn-primary {
  background: #fff;
  color: var(--primary);
  box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}
.cta .btn-primary:hover {
  background: #fff;
  color: var(--primary-dark);
  box-shadow: 0 8px 30px rgba(0,0,0,0.2);
  transform: translateY(-2px);
}

.cta-disclaimer {
  margin-top: 28px;
  font-size: 0.82rem;
  opacity: 0.6;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== Footer ===== */
.footer {
  padding: 60px 0 40px;
  background: var(--bg-white);
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 40px;
  flex-wrap: wrap;
}

.footer-brand {
  max-width: 300px;
}

.footer-brand h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.footer-brand p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.footer-links-group h4 {
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.footer-links-group a {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 10px;
}

.footer-links-group a:hover {
  color: var(--primary);
}

.footer-bottom {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 12px;
}

/* ===== Legal Pages ===== */
.legal-page {
  padding: 120px 0 80px;
}

.legal-page h1 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.legal-page .updated {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 40px;
}

.legal-content {
  max-width: 720px;
}

.legal-content h2 {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 36px 0 12px;
  color: var(--text);
}

.legal-content h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 24px 0 10px;
  color: var(--text);
}

.legal-content p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 14px;
  line-height: 1.75;
}

.legal-content ul {
  margin-bottom: 14px;
  padding-left: 20px;
}

.legal-content li {
  list-style: disc;
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 6px;
  line-height: 1.65;
}

.legal-content a {
  color: var(--primary);
  text-decoration: underline;
  text-decoration-color: var(--primary-light);
  text-underline-offset: 3px;
}

/* ===== Support Page ===== */
.support-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  margin-bottom: 56px;
}

.support-card {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  transition: all var(--transition);
}

.support-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.support-card .support-icon {
  width: 56px; height: 56px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin: 0 auto 16px;
  background: var(--primary-light);
  color: var(--primary);
}

.support-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.support-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

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

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

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .features-grid {
    grid-template-columns: 1fr;
  }
  .researchers-grid {
    grid-template-columns: 1fr;
  }
  .extras-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px; left: 0; right: 0;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
    padding: 20px 24px;
    gap: 16px;
    box-shadow: var(--shadow);
  }
  .mobile-menu-btn { display: block; }

  .hero { padding: 120px 0 60px; }
  .hero h1 { font-size: 2rem; }
  .features, .science, .faq, .extras { padding: 64px 0; }
  .cta { padding: 64px 0; }

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

  .footer-inner { flex-direction: column; gap: 32px; }
  .footer-bottom { flex-direction: column; text-align: center; }
}

@media (max-width: 480px) {
  .hero-buttons { flex-direction: column; align-items: center; }
  .btn { width: 100%; justify-content: center; }
}