/* ==================== 全局样式 ==================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #06b6d4;
  --primary-dark: #0891b2;
  --bg-dark: #0f172a;
  --bg-darker: #0a0f1f;
  --card-bg: #1e293b;
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --border-color: #334155;
  --accent: #06b6d4;
  --accent-light: #22d3ee;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

/* ==================== 导航栏 ==================== */
nav {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  transition: all 0.3s ease;
  background-color: transparent;
}

nav.scrolled {
  background-color: rgba(15, 23, 42, 0.8);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
}

.nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: bold;
  font-size: 1.125rem;
}

.logo-icon {
  width: 2rem;
  height: 2rem;
  background: linear-gradient(135deg, #06b6d4 0%, #1e3a8a 100%);
  border-radius: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: bold;
  font-size: 0.75rem;
}

.nav-links {
  display: none;
  gap: 2rem;
  align-items: center;
}

.nav-links a {
  color: var(--text-primary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.3s ease;
}

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

.lang-selector {
  display: flex;
  gap: 0.5rem;
  margin-left: 1rem;
}

.lang-btn {
  padding: 0.25rem 0.75rem;
  background-color: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  cursor: pointer;
  border-radius: 0.375rem;
  font-size: 0.75rem;
  transition: all 0.3s ease;
}

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

.lang-btn.active {
  background-color: var(--accent);
  border-color: var(--accent);
  color: var(--bg-dark);
}

.get-started-btn {
  padding: 0.5rem 1rem;
  background-color: var(--accent);
  color: var(--bg-dark);
  border: none;
  border-radius: 0.375rem;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.875rem;
  transition: background-color 0.3s ease;
}

.get-started-btn:hover {
  background-color: var(--primary-dark);
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
  }
}

/* ==================== Hero 区域 ==================== */
.hero {
  position: relative;
  padding-top: 8rem;
  padding-bottom: 5rem;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 5rem;
  right: 0;
  width: 24rem;
  height: 24rem;
  background: radial-gradient(circle, rgba(6, 182, 212, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 24rem;
  height: 24rem;
  background: radial-gradient(circle, rgba(30, 58, 138, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero-content {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1rem;
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  background-color: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.3);
  border-radius: 9999px;
  margin-bottom: 1.5rem;
  font-size: 0.875rem;
  color: var(--accent);
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, #06b6d4 0%, #38bdf8 50%, #06b6d4 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .subtitle {
  font-size: 1.875rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.hero .description {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 42rem;
  margin: 0 auto 2rem;
}

.hero-buttons {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  justify-content: center;
  margin-bottom: 3rem;
}

.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
}

.btn-primary {
  background-color: var(--accent);
  color: var(--bg-dark);
}

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

.btn-outline {
  background-color: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

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

/* 链接按钮样式 */
a.btn {
  text-decoration: none;
  display: inline-flex;
}

a.btn:visited {
  color: inherit;
}

@media (min-width: 640px) {
  .hero-buttons {
    flex-direction: row;
  }

  .hero h1 {
    font-size: 4rem;
  }

  .hero .subtitle {
    font-size: 2.25rem;
  }
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}

.stat {
  text-align: center;
}

.stat-value {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

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

/* ==================== 特性区域 ==================== */
.features {
  padding: 5rem 1rem;
  background-color: rgba(30, 41, 59, 0.3);
}

.container {
  max-width: 1280px;
  margin: 0 auto;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 1rem;
  text-align: center;
}

.section-title .accent {
  color: var(--accent);
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.125rem;
  max-width: 42rem;
  margin: 0 auto 3rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.feature-card {
  background-color: rgba(30, 41, 59, 0.5);
  border: 1px solid var(--border-color);
  padding: 1.5rem;
  border-radius: 0.75rem;
  transition: all 0.3s ease;
}

.feature-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  background-color: rgba(30, 41, 59, 0.8);
}

.feature-icon {
  width: 3rem;
  height: 3rem;
  background: linear-gradient(135deg, var(--accent) 0%, var(--primary-dark) 100%);
  border-radius: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  font-size: 1.5rem;
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

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

/* ==================== MDE 区域 ==================== */
.mde {
  padding: 5rem 1rem;
}

.mde-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  align-items: center;
}

@media (min-width: 768px) {
  .mde-content {
    grid-template-columns: 1fr 1fr;
  }
}

.mde-text h2 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
}

.mde-text p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  font-size: 1rem;
}

.mde-features {
  list-style: none;
}

.mde-features li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

.mde-features li::before {
  content: '';
  width: 0.5rem;
  height: 0.5rem;
  background-color: var(--accent);
  border-radius: 50%;
}

.mde-preview {
  background: linear-gradient(135deg, var(--card-bg) 0%, rgba(30, 58, 138, 0.2) 100%);
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  padding: 2rem;
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
}

/* ==================== 下载区域 ==================== */
.download {
  padding: 5rem 1rem;
  background: linear-gradient(180deg, rgba(30, 58, 138, 0.1) 0%, transparent 100%);
}

.download-content {
  max-width: 48rem;
  margin: 0 auto;
  text-align: center;
}

.download-content h2 {
  font-size: 2.25rem;
  margin-bottom: 1.5rem;
}

.download-content p {
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-size: 1.125rem;
}

.download-box {
  background-color: rgba(30, 41, 59, 0.5);
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  padding: 2rem;
  margin-bottom: 2rem;
}

.download-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .download-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.download-item {
  text-align: left;
}

.download-item h3 {
  margin-bottom: 0.5rem;
}

.download-item p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: 1rem;
}

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

/* ==================== 页脚 ==================== */
footer {
  border-top: 1px solid var(--border-color);
  padding: 3rem 1rem;
  background-color: rgba(10, 15, 31, 0.5);
}

.footer-content {
  max-width: 1280px;
  margin: 0 auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-section h3 {
  margin-bottom: 1rem;
  font-size: 1rem;
}

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

.footer-section li {
  margin-bottom: 0.5rem;
}

.footer-section a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.3s ease;
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer-bottom p {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.3s ease;
}

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

/* ==================== 响应式设计 ==================== */
@media (max-width: 640px) {
  .hero h1 {
    font-size: 2rem;
  }

  .hero .subtitle {
    font-size: 1.25rem;
  }

  .section-title {
    font-size: 1.875rem;
  }

  .mde-text h2 {
    font-size: 1.5rem;
  }
}

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

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.slide-in {
  animation: slideIn 0.6s ease-out;
}