/* VitaDuo Official Website - Shared Styles */

:root {
  --primary: #1a365d;
  --primary-light: #2a4a7f;
  --primary-dark: #0f2240;
  --secondary: #f59e0b;
  --secondary-light: #fbbf24;
  --secondary-dark: #d97706;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --bg-dark: #0f172a;
  --text: #1a202c;
  --text-light: #64748b;
  --text-white: #ffffff;
  --accent: #e2e8f0;
  --border: #e2e8f0;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --max-width: 1200px;
  --transition: 0.3s ease;
}

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

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

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

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

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

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

img {
  max-width: 100%;
  height: auto;
}

/* ========== Navigation ========== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  transition: box-shadow var(--transition);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: -0.02em;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-link {
  display: inline-block;
  padding: 8px 16px;
  color: var(--text);
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

.nav-link:hover {
  color: var(--primary);
  background: var(--bg-alt);
}

.nav-link.active {
  color: var(--primary);
  background: rgba(26, 54, 93, 0.08);
}

.lang-btn {
  padding: 6px 16px;
  background: var(--primary);
  color: var(--text-white);
  border: none;
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font);
}

.lang-btn:hover {
  background: var(--primary-light);
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all var(--transition);
}

/* ========== Hero Section ========== */
.hero {
  position: relative;
  padding: 140px 0 80px;
  overflow: hidden;
  background: linear-gradient(135deg, #f0f4ff 0%, #ffffff 50%, #fffbeb 100%);
}

.hero .container {
  display: flex;
  align-items: center;
  gap: 60px;
}

.hero-content {
  flex: 1;
  max-width: 600px;
}

.hero-title {
  font-size: 3.25rem;
  font-weight: 800;
  line-height: 1.15;
  color: var(--primary-dark);
  margin-bottom: 24px;
  letter-spacing: -0.02em;
}

.gradient-text {
  background: linear-gradient(135deg, var(--secondary), var(--secondary-dark));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 32px;
}

.hero-stats {
  display: flex;
  gap: 32px;
  margin-bottom: 40px;
}

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

.stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
}

.stat-label {
  font-size: 0.8125rem;
  color: var(--text-light);
  margin-top: 4px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-image {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
}

.phone-mockup {
  width: 280px;
  height: 560px;
  background: var(--primary-dark);
  border-radius: 40px;
  padding: 12px;
  box-shadow: var(--shadow-xl), 0 0 60px rgba(26, 54, 93, 0.15);
  position: relative;
}

.phone-mockup::before {
  content: "";
  position: absolute;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 24px;
  background: #000;
  border-radius: 12px;
  z-index: 2;
}

.phone-screen {
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.app-preview {
  text-align: center;
  color: var(--text-white);
}

.match-card {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 32px 24px;
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.match-avatar {
  font-size: 3rem;
  margin-bottom: 16px;
}

.match-name {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.match-score {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--secondary);
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.floating-circle {
  position: absolute;
  border-radius: 50%;
  opacity: 0.08;
}

.circle-1 {
  width: 400px;
  height: 400px;
  background: var(--primary);
  top: -100px;
  right: -100px;
  animation: float 8s ease-in-out infinite;
}

.circle-2 {
  width: 300px;
  height: 300px;
  background: var(--secondary);
  bottom: -80px;
  left: -80px;
  animation: float 10s ease-in-out infinite reverse;
}

.circle-3 {
  width: 200px;
  height: 200px;
  background: var(--primary);
  top: 40%;
  left: 30%;
  animation: float 12s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
  font-family: var(--font);
}

.btn-primary {
  background: var(--primary);
  color: var(--text-white);
  box-shadow: 0 4px 14px rgba(26, 54, 93, 0.3);
}

.btn-primary:hover {
  background: var(--primary-light);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(26, 54, 93, 0.4);
  color: var(--text-white);
}

.btn-secondary {
  background: var(--text-white);
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-secondary:hover {
  background: var(--primary);
  color: var(--text-white);
  transform: translateY(-2px);
}

.btn-icon {
  width: 20px;
  height: 20px;
}

/* ========== Section Shared ========== */
.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-light);
  max-width: 600px;
  margin: 0 auto;
}

/* ========== Features ========== */
.features {
  padding: 100px 0;
  background: var(--bg);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

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

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

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 20px;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary-dark);
  margin-bottom: 12px;
}

.feature-desc {
  font-size: 0.9375rem;
  color: var(--text-light);
  line-height: 1.7;
}

/* ========== How It Works ========== */
.how-it-works {
  padding: 100px 0;
  background: var(--bg-alt);
}

.steps {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  justify-content: center;
}

.step {
  flex: 1;
  max-width: 320px;
  text-align: center;
  background: var(--bg);
  border-radius: var(--radius);
  padding: 40px 28px;
  box-shadow: var(--shadow);
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: var(--text-white);
  font-size: 1.5rem;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 24px;
}

.step-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary-dark);
  margin-bottom: 12px;
}

.step-desc {
  font-size: 0.9375rem;
  color: var(--text-light);
  line-height: 1.7;
}

.step-connector {
  display: flex;
  align-items: center;
  font-size: 2rem;
  color: var(--secondary);
  font-weight: 700;
  padding-top: 60px;
}

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

.science-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.science-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

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

.science-number {
  font-size: 3rem;
  font-weight: 800;
  color: var(--secondary);
  opacity: 0.3;
  margin-bottom: 12px;
}

.science-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--primary-dark);
  margin-bottom: 12px;
}

.science-desc {
  font-size: 0.9375rem;
  color: var(--text-light);
  line-height: 1.7;
}

.science-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}

.science-tag {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(26, 54, 93, 0.08);
  color: var(--primary);
  border-radius: 20px;
  font-size: 0.8125rem;
  font-weight: 500;
}

.science-link {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--secondary-dark);
}

.science-link:hover {
  color: var(--secondary);
}

/* ========== Download ========== */
.download {
  padding: 100px 0;
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, var(--primary-light) 100%);
  color: var(--text-white);
}

.download-content {
  text-align: center;
}

.download-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text-white);
}

.download-subtitle {
  font-size: 1.125rem;
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 40px;
}

.download-buttons {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

.store-button {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: var(--text-white);
  color: var(--text);
  padding: 14px 28px;
  border-radius: var(--radius);
  text-decoration: none;
  transition: all var(--transition);
}

.store-button:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
  color: var(--text);
}

.store-icon {
  width: 28px;
  height: 28px;
}

.store-text {
  text-align: left;
}

.store-subtitle {
  font-size: 0.75rem;
  color: var(--text-light);
  line-height: 1;
}

.store-name {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.3;
}

/* ========== Footer ========== */
.footer {
  padding: 64px 0 32px;
  background: var(--bg-dark);
  color: rgba(255, 255, 255, 0.7);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  gap: 48px;
  margin-bottom: 48px;
}

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

.footer-brand .logo {
  color: var(--text-white);
  display: block;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 0.9375rem;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  gap: 64px;
}

.footer-column h4 {
  color: var(--text-white);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.footer-column ul {
  list-style: none;
}

.footer-column li {
  margin-bottom: 12px;
}

.footer-column a {
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.9375rem;
  transition: color var(--transition);
}

.footer-column a:hover {
  color: var(--secondary);
}

.social-links {
  display: flex;
  gap: 12px;
}

.social-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 50%;
  color: rgba(255, 255, 255, 0.6);
  transition: all var(--transition);
}

.social-links a:hover {
  background: var(--secondary);
  color: var(--text-white);
}

.social-links svg {
  width: 20px;
  height: 20px;
}

.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: 0.875rem;
}

.footer-bottom p {
  margin-bottom: 8px;
}

/* ========== Legal Pages ========== */
.legal-page {
  padding: 120px 0 80px;
  min-height: 100vh;
}

.legal-content {
  max-width: 800px;
  margin: 0 auto;
  background: var(--bg);
  padding: 48px;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
}

.legal-title {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--primary-dark);
}

.legal-subtitle {
  font-size: 0.9375rem;
  color: var(--text-light);
  margin-bottom: 32px;
}

.effective-date {
  color: var(--text-light);
  font-size: 0.875rem;
  margin-bottom: 32px;
}

.legal-section {
  margin-bottom: 32px;
}

.legal-section h2 {
  font-size: 1.375rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--primary-dark);
  padding-bottom: 8px;
  border-bottom: 2px solid var(--secondary);
  display: inline-block;
}

.legal-section h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 8px;
  margin-top: 20px;
  color: var(--primary);
}

.legal-section p {
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 12px;
}

.legal-section ul, .legal-section ol {
  margin-left: 24px;
  margin-bottom: 16px;
}

.legal-section li {
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 8px;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 24px;
  color: var(--primary);
  font-weight: 500;
  font-size: 0.9375rem;
}

.back-link:hover {
  color: var(--secondary-dark);
}

.back-link svg {
  width: 18px;
  height: 18px;
}

.contact-box {
  background: var(--bg-alt);
  padding: 24px;
  border-radius: var(--radius);
  margin-top: 24px;
  border-left: 4px solid var(--secondary);
}

.contact-box p {
  margin-bottom: 8px;
}

.contact-box strong {
  color: var(--text);
}

.legal-compliance {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  color: var(--text-light);
  font-size: 0.875rem;
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .science-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero .container {
    gap: 40px;
  }
  .hero-title {
    font-size: 2.75rem;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 24px;
    gap: 8px;
    box-shadow: var(--shadow-lg);
    border-top: 1px solid var(--border);
  }
  .nav-menu.active {
    display: flex;
  }
  .nav-toggle {
    display: flex;
  }
  .hero {
    padding: 120px 0 60px;
  }
  .hero .container {
    flex-direction: column;
    gap: 40px;
  }
  .hero-content {
    text-align: center;
    max-width: 100%;
  }
  .hero-stats {
    justify-content: center;
  }
  .hero-buttons {
    justify-content: center;
  }
  .hero-title {
    font-size: 2.25rem;
  }
  .hero-image {
    order: -1;
  }
  .phone-mockup {
    width: 220px;
    height: 440px;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .science-grid {
    grid-template-columns: 1fr;
  }
  .steps {
    flex-direction: column;
    align-items: center;
  }
  .step-connector {
    transform: rotate(90deg);
    padding-top: 0;
    margin: 0;
  }
  .footer-content {
    flex-direction: column;
    gap: 32px;
  }
  .footer-links {
    flex-direction: column;
    gap: 32px;
  }
  .legal-content {
    padding: 24px;
  }
  .legal-title {
    font-size: 1.75rem;
  }
  .section-title {
    font-size: 1.75rem;
  }
  .download-title {
    font-size: 1.75rem;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 1.875rem;
  }
  .hero-subtitle {
    font-size: 1rem;
  }
  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }
  .btn {
    width: 100%;
    justify-content: center;
  }
  .download-buttons {
    flex-direction: column;
    align-items: center;
  }
  .store-button {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }
  .hero-stats {
    gap: 20px;
  }
}