/* AI Startup Cases - Custom Styles */
/* 配合 Tailwind CDN 使用 */

/* 自定义字体 */
@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@400;600;700&family=Source+Sans+3:wght@300;400;500;600;700&display=swap');

:root {
  --font-heading: 'Playfair Display', Georgia, serif;
  --font-body: 'Source Sans 3', system-ui, sans-serif;
  --color-primary: #1a1a2e;
  --color-secondary: #16213e;
  --color-accent: #e94560;
  --color-accent-light: #ff6b6b;
  --color-text: #2d3436;
  --color-text-light: #636e72;
  --color-bg: #fefefe;
  --color-bg-alt: #f8f9fa;
  --color-border: #e9ecef;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.8;
  font-size: 17px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-primary);
}

h1 { font-size: 2.75rem; margin-bottom: 1rem; }
h2 { font-size: 2rem; margin-bottom: 0.875rem; margin-top: 2.5rem; }
h3 { font-size: 1.5rem; margin-bottom: 0.75rem; margin-top: 2rem; }

p {
  margin-bottom: 1.25rem;
  color: var(--color-text);
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

/* Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(254, 254, 254, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  padding: 1rem 0;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
}

.nav-logo span {
  color: var(--color-accent);
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--color-text);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.3s ease;
}

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

/* Hero Section */
.hero {
  padding: 6rem 2rem;
  text-align: center;
  background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-alt) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(233, 69, 96, 0.03) 0%, transparent 50%);
  animation: pulse 15s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50% { transform: scale(1.1); opacity: 1; }
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: 1.5rem;
  animation: fadeInUp 0.8s ease-out;
}

.hero p {
  font-size: 1.25rem;
  color: var(--color-text-light);
  margin-bottom: 2rem;
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

/* Search Box */
.search-container {
  max-width: 600px;
  margin: 0 auto 3rem;
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

.search-box {
  display: flex;
  gap: 0;
  background: white;
  border-radius: 50px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  overflow: hidden;
  border: 2px solid var(--color-border);
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.search-box:focus-within {
  border-color: var(--color-accent);
  box-shadow: 0 4px 25px rgba(233, 69, 96, 0.15);
}

.search-box input {
  flex: 1;
  padding: 1rem 1.5rem;
  border: none;
  font-size: 1rem;
  font-family: var(--font-body);
  outline: none;
  background: transparent;
}

.search-box button {
  padding: 1rem 2rem;
  background: var(--color-accent);
  color: white;
  border: none;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.3s ease;
}

.search-box button:hover {
  background: var(--color-accent-light);
}

/* Cases Grid */
.cases-section {
  padding: 4rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
}

.section-title {
  text-align: center;
  margin-bottom: 3rem;
}

.section-title h2 {
  margin-top: 0;
  position: relative;
  display: inline-block;
}

.section-title h2::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 2rem;
}

/* Case Card */
.case-card {
  background: white;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  border: 1px solid var(--color-border);
  animation: fadeInUp 0.6s ease-out both;
}

.case-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.1);
}

.case-card-image {
  height: 200px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  position: relative;
  overflow: hidden;
}

.case-card-image::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(45deg, transparent 30%, rgba(255,255,255,0.1) 50%, transparent 70%);
  transform: translateX(-100%);
  transition: transform 0.6s ease;
}

.case-card:hover .case-card-image::before {
  transform: translateX(100%);
}

.case-card-content {
  padding: 1.5rem;
}

.case-card-category {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background: var(--color-bg-alt);
  color: var(--color-accent);
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: 20px;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.case-card h3 {
  margin-top: 0;
  margin-bottom: 0.5rem;
  font-size: 1.25rem;
}

.case-card p {
  color: var(--color-text-light);
  font-size: 0.95rem;
  margin-bottom: 1rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.case-card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  color: var(--color-accent);
}

.case-card-link:hover {
  gap: 0.75rem;
}

/* Article Page */
.article-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 3rem 2rem;
}

.article-header {
  margin-bottom: 3rem;
  animation: fadeInUp 0.6s ease-out;
}

.article-breadcrumb {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
  color: var(--color-text-light);
}

.article-breadcrumb a {
  color: var(--color-text-light);
}

.article-breadcrumb a:hover {
  color: var(--color-accent);
}

.article-meta {
  display: flex;
  gap: 1.5rem;
  margin-top: 1rem;
  color: var(--color-text-light);
  font-size: 0.9rem;
}

.article-content {
  animation: fadeInUp 0.6s ease-out 0.2s both;
}

.article-content p {
  text-align: justify;
}

.article-content ul, .article-content ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

.article-content li {
  margin-bottom: 0.5rem;
}

.article-content blockquote {
  border-left: 4px solid var(--color-accent);
  padding-left: 1.5rem;
  margin: 2rem 0;
  font-style: italic;
  color: var(--color-text-light);
}

/* Info Box */
.info-box {
  background: var(--color-bg-alt);
  border-radius: 12px;
  padding: 1.5rem;
  margin: 2rem 0;
  border-left: 4px solid var(--color-accent);
}

.info-box h4 {
  margin-top: 0;
  margin-bottom: 0.5rem;
  color: var(--color-primary);
}

/* Tags */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 2rem 0;
}

.tag {
  padding: 0.5rem 1rem;
  background: var(--color-bg-alt);
  border-radius: 20px;
  font-size: 0.85rem;
  color: var(--color-text-light);
  transition: all 0.3s ease;
}

.tag:hover {
  background: var(--color-accent);
  color: white;
}

/* Related Cases */
.related-cases {
  margin-top: 4rem;
  padding-top: 3rem;
  border-top: 1px solid var(--color-border);
}

.related-cases h3 {
  text-align: center;
  margin-bottom: 2rem;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.5rem;
}

/* Footer */
.footer {
  background: var(--color-primary);
  color: white;
  padding: 4rem 2rem 2rem;
  margin-top: 4rem;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 3rem;
}

.footer h4 {
  color: white;
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
}

.footer p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.95rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.75rem;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: var(--color-accent-light);
}

.footer-bottom {
  max-width: 1200px;
  margin: 3rem auto 0;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.9rem;
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* Staggered animation delays for grid items */
.case-card:nth-child(1) { animation-delay: 0.1s; }
.case-card:nth-child(2) { animation-delay: 0.15s; }
.case-card:nth-child(3) { animation-delay: 0.2s; }
.case-card:nth-child(4) { animation-delay: 0.25s; }
.case-card:nth-child(5) { animation-delay: 0.3s; }
.case-card:nth-child(6) { animation-delay: 0.35s; }
.case-card:nth-child(7) { animation-delay: 0.4s; }
.case-card:nth-child(8) { animation-delay: 0.45s; }
.case-card:nth-child(9) { animation-delay: 0.5s; }
.case-card:nth-child(10) { animation-delay: 0.55s; }

/* Mobile Navigation */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  display: block;
  width: 25px;
  height: 3px;
  background: var(--color-primary);
  margin: 5px 0;
  transition: all 0.3s ease;
}

/* Responsive Design */
@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
  
  .hero { padding: 4rem 1.5rem; }
  .hero h1 { font-size: 2.25rem; }
  .hero p { font-size: 1.1rem; }
  
  .nav-toggle { display: block; }
  
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 1rem 2rem;
    gap: 1rem;
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
  }
  
  .nav-links.active { display: flex; }
  
  .cases-grid {
    grid-template-columns: 1fr;
  }
  
  .search-box {
    flex-direction: column;
    border-radius: 16px;
  }
  
  .search-box input {
    padding: 1rem;
    text-align: center;
  }
  
  .search-box button {
    border-radius: 0 0 14px 14px;
  }
  
  .article-container {
    padding: 2rem 1.5rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
}

/* Category Filter */
.category-filter {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.category-btn {
  padding: 0.5rem 1.25rem;
  background: white;
  border: 2px solid var(--color-border);
  border-radius: 25px;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text);
  cursor: pointer;
  transition: all 0.3s ease;
}

.category-btn:hover,
.category-btn.active {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: white;
}

/* Search Results */
.search-results {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: white;
  border-radius: 16px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
  margin-top: 0.5rem;
  max-height: 400px;
  overflow-y: auto;
  z-index: 100;
}

.search-results.active {
  display: block;
}

.search-result-item {
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--color-border);
  transition: background 0.2s ease;
}

.search-result-item:last-child {
  border-bottom: none;
}

.search-result-item:hover {
  background: var(--color-bg-alt);
}

.search-result-item h4 {
  margin: 0 0 0.25rem;
  font-size: 1rem;
}

.search-result-item p {
  margin: 0;
  font-size: 0.85rem;
  color: var(--color-text-light);
}

.no-results {
  padding: 2rem;
  text-align: center;
  color: var(--color-text-light);
}

/* Table of Contents */
.toc {
  background: var(--color-bg-alt);
  border-radius: 12px;
  padding: 1.5rem;
  margin: 2rem 0;
}

.toc h4 {
  margin-top: 0;
  margin-bottom: 1rem;
  font-size: 1rem;
}

.toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.toc li {
  margin-bottom: 0.5rem;
}

.toc a {
  color: var(--color-text-light);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.toc a::before {
  content: '→';
  color: var(--color-accent);
}

.toc a:hover {
  color: var(--color-accent);
}

/* Scroll to top button */
.scroll-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  background: var(--color-accent);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(233, 69, 96, 0.3);
  z-index: 99;
}

.scroll-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-top:hover {
  background: var(--color-accent-light);
  transform: translateY(-3px);
}

/* Statistics Section */
.stats-section {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  padding: 3rem 2rem;
  background: var(--color-bg-alt);
  margin: 3rem 0;
}

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

.stat-number {
  font-family: var(--font-heading);
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}

.stat-label {
  color: var(--color-text-light);
  font-size: 0.95rem;
  margin-top: 0.5rem;
}

/* Print Styles */
@media print {
  .nav, .footer, .scroll-top, .search-container {
    display: none;
  }
  
  .article-container {
    max-width: 100%;
    padding: 0;
  }
  
  body {
    font-size: 12pt;
    line-height: 1.5;
  }
}