/* ============================================
   lovemo - 年轻人AI伴侣聊天应用官网样式
   ============================================ */

/* CSS Variables */
:root {
  /* Colors */
  --color-primary-start: #9B59B6;
  --color-primary-end: #E91E63;
  --color-primary: linear-gradient(135deg, var(--color-primary-start), var(--color-primary-end));
  --color-secondary: #2C3E50;
  --color-accent: #FF6B9D;
  --color-background: #FAFAFA;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-text-muted: #999999;
  --color-white: #FFFFFF;
  --color-border: #E8E8E8;
  --color-shadow: rgba(155, 89, 182, 0.15);

  /* Typography */
  --font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  --spacing-3xl: 6rem;

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 400ms ease-out;

  /* Container */
  --container-max: 1200px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

ul {
  list-style: none;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.nav-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: 1.25rem;
  font-weight: 700;
  background: var(--color-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-logo img {
  width: 40px;
  height: 40px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
}

.nav-link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text);
  transition: color var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-accent);
}

.nav-download {
  padding: var(--spacing-xs) var(--spacing-md);
  background: var(--color-primary);
  color: var(--color-white) !important;
  border-radius: var(--radius-full);
  font-weight: 600;
}

.nav-download:hover {
  transform: scale(1.05);
  box-shadow: 0 4px 20px var(--color-shadow);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 24px;
  height: 18px;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  padding-top: 130px;
  padding-bottom: var(--spacing-3xl);
  background: linear-gradient(180deg, rgba(155, 89, 182, 0.05) 0%, rgba(233, 30, 99, 0.03) 100%);
  overflow: hidden;
}

.hero-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-3xl);
  align-items: center;
}

.hero-content {
  animation: none;
}

.hero-content.slide-from-left {
  animation: slideFromLeft var(--transition-slow) forwards;
}

.hero-content.slide-from-right {
  animation: slideFromRight var(--transition-slow) forwards;
}

.hero-image {
  animation: none;
}

.hero-image.slide-from-left {
  animation: slideFromLeft var(--transition-slow) forwards;
}

.hero-image.slide-from-right {
  animation: slideFromRight var(--transition-slow) forwards;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--color-secondary);
}

.hero-title .highlight {
  background: var(--color-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

.hero-buttons {
  display: flex;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-white);
  box-shadow: 0 4px 20px var(--color-shadow);
}

.btn-primary:hover {
  transform: scale(1.05);
  box-shadow: 0 6px 30px var(--color-shadow);
}

.btn-primary:active {
  transform: scale(0.98);
}

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

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.hero-stats {
  display: flex;
  gap: var(--spacing-xl);
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-number {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--color-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.hero-image img {
  width: 320px;
  height: auto;
  margin: 0 auto;
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 60px var(--color-shadow);
}

/* ============================================
   Section Common Styles
   ============================================ */
.section-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-secondary);
  margin-bottom: var(--spacing-sm);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-light);
}

/* ============================================
   Features Section
   ============================================ */
.features {
  padding: var(--spacing-3xl) 0;
}

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

.feature-card {
  background: var(--color-white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
  transition: all var(--transition-normal);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px var(--color-shadow);
}

.feature-icon {
  width: 60px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-md);
}

.feature-icon svg {
  color: var(--color-white);
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-secondary);
  margin-bottom: var(--spacing-xs);
}

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

/* ============================================
   Guide Section
   ============================================ */
.guide {
  padding: var(--spacing-3xl) 0;
  background: linear-gradient(180deg, rgba(155, 89, 182, 0.03) 0%, rgba(233, 30, 99, 0.02) 100%);
}

.guide-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-xl);
  position: relative;
}

.guide-steps::before {
  content: '';
  position: absolute;
  top: 35px;
  left: 15%;
  right: 15%;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary-start), var(--color-primary-end));
  z-index: 0;
}

.guide-step {
  position: relative;
  z-index: 1;
  text-align: center;
  background: var(--color-white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.step-number {
  width: 70px;
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--spacing-md);
  font-size: 1.75rem;
  font-weight: 700;
  background: var(--color-primary);
  color: var(--color-white);
  border-radius: 50%;
}

.step-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-secondary);
  margin-bottom: var(--spacing-xs);
}

.step-desc {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  line-height: 1.6;
}

/* ============================================
   Download Section
   ============================================ */
.download {
  padding: var(--spacing-3xl) 0;
}

.download-content {
  text-align: center;
  background: var(--color-primary);
  border-radius: var(--radius-xl);
  padding: var(--spacing-3xl);
  color: var(--color-white);
}

.download-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.download-subtitle {
  font-size: 1.125rem;
  opacity: 0.9;
  margin-bottom: var(--spacing-xl);
}

.download-buttons {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  background: var(--color-white);
  color: var(--color-secondary);
  border-radius: var(--radius-lg);
  font-weight: 600;
  transition: all var(--transition-fast);
}

.btn-download:hover {
  transform: scale(1.05);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
}

.btn-download:active {
  transform: scale(0.98);
}

.download-platform {
  display: block;
  font-size: 1.125rem;
}

.download-size {
  display: block;
  font-size: 0.75rem;
  font-weight: 400;
  opacity: 0.7;
}

.version-info {
  display: flex;
  justify-content: center;
  gap: var(--spacing-lg);
  font-size: 0.875rem;
  opacity: 0.85;
}

.version-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

/* ============================================
   Reviews Section
   ============================================ */
.reviews {
  padding: var(--spacing-3xl) 0;
  background-color: var(--color-white);
}

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

.review-card {
  background: var(--color-background);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  transition: all var(--transition-normal);
}

.review-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px var(--color-shadow);
}

.review-rating {
  color: #FFD700;
  margin-bottom: var(--spacing-sm);
}

.review-text {
  font-size: 0.9375rem;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: var(--spacing-md);
}

.review-author {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.author-avatar {
  font-size: 1.5rem;
}

.author-name {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-light);
}

/* ============================================
   FAQ Section
   ============================================ */
.faq {
  padding: var(--spacing-3xl) 0;
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--color-white);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-sm);
  overflow: hidden;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.03);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) var(--spacing-lg);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-secondary);
  text-align: left;
  transition: all var(--transition-fast);
}

.faq-question:hover {
  color: var(--color-accent);
}

.faq-icon {
  flex-shrink: 0;
  transition: transform var(--transition-fast);
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-normal);
}

.faq-item.active .faq-answer {
  max-height: 200px;
}

.faq-answer p {
  padding: 0 var(--spacing-lg) var(--spacing-md);
  font-size: 0.9375rem;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background: var(--color-secondary);
  color: var(--color-white);
  padding: var(--spacing-3xl) 0 var(--spacing-lg);
}

.footer-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.footer-main {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--spacing-3xl);
  margin-bottom: var(--spacing-2xl);
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.footer-logo img {
  width: 36px;
  height: 36px;
}

.footer-slogan {
  font-size: 0.9375rem;
  opacity: 0.8;
}

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

.footer-column h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.footer-column ul {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.footer-column a {
  font-size: 0.875rem;
  opacity: 0.8;
  transition: opacity var(--transition-fast);
}

.footer-column a:hover {
  opacity: 1;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--spacing-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.copyright {
  font-size: 0.875rem;
  opacity: 0.7;
}

.footer-social {
  display: flex;
  gap: var(--spacing-md);
}

.footer-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  opacity: 0.8;
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  opacity: 1;
  background: var(--color-accent);
}

/* ============================================
   Animations
   ============================================ */
@keyframes slideFromLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideFromRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

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

.fade-in-up {
  opacity: 0;
  animation: fadeInUp 0.6s ease forwards;
  animation-delay: var(--delay);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 968px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--color-white);
    flex-direction: column;
    padding: var(--spacing-lg);
    gap: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
  }

  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-download {
    width: 100%;
    justify-content: center;
  }

  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--spacing-xl);
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-stats {
    justify-content: center;
  }

  .hero-image {
    order: -1;
  }

  .hero-image img {
    width: 280px;
  }

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

  .guide-steps {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .guide-steps::before {
    display: none;
  }

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

  .footer-main {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    text-align: center;
  }

  .footer-links {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .section-title {
    font-size: 2rem;
  }

  .download-content {
    padding: var(--spacing-xl);
  }

  .download-title {
    font-size: 1.75rem;
  }

  .version-info {
    flex-direction: column;
    gap: var(--spacing-xs);
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }

  .stat-item {
    flex: 1;
  }

  .hero-image img {
    width: 240px;
  }

  .btn-download {
    width: 100%;
    justify-content: center;
  }
}