/* 基础样式和CSS变量 */
:root {
  /* 亮色主题 */
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --secondary-color: #64748b;
  --accent-color: #f59e0b;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-modal: rgba(0, 0, 0, 0.5);
  
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-tertiary: #94a3b8;
  --text-inverse: #ffffff;
  
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  --transition: all 0.2s ease-in-out;
  --transition-slow: all 0.3s ease-in-out;
}

/* 暗色主题 */
[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --bg-card: #1e293b;
  --bg-modal: rgba(0, 0, 0, 0.8);
  
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-tertiary: #94a3b8;
  
  --border-color: #334155;
  --border-hover: #475569;
}

/* 基础重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: var(--transition);
}

/* 通用样式 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

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

.section-header h2 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

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

/* 按钮样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 500;
  text-decoration: none;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--primary-color);
  color: var(--text-inverse);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

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

.btn-outline {
  background-color: transparent;
  color: var(--primary-color);
  border: 2px solid var(--primary-color);
}

.btn-outline:hover {
  background-color: var(--primary-color);
  color: var(--text-inverse);
}

/* 导航栏 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background-color: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
  z-index: 1000;
  transition: var(--transition);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-brand h1 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
}

.brand-tagline {
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  padding: 0.5rem 0;
  position: relative;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: var(--transition);
}

.nav-link:hover::after {
  width: 100%;
}

.nav-cta {
  background-color: var(--primary-color);
  color: var(--text-inverse) !important;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
}

.nav-cta:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
}

.nav-cta::after {
  display: none;
}

.nav-admin {
  color: var(--text-tertiary) !important;
  font-size: 0.875rem;
}

.theme-toggle {
  background: none;
  border: none;
  font-size: 1.25rem;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: var(--radius-md);
  transition: var(--transition);
}

.theme-toggle:hover {
  background-color: var(--bg-secondary);
}

/* 主要内容 */
main {
  margin-top: 4rem;
}

/* 英雄区域 */
.hero {
  padding: 4rem 0;
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 30% 20%, rgba(37, 99, 235, 0.1) 0%, transparent 50%),
              radial-gradient(circle at 70% 80%, rgba(245, 158, 11, 0.1) 0%, transparent 50%);
  pointer-events: none;
}

.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.1;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
}

.highlight {
  color: var(--primary-color);
  position: relative;
}

.highlight::after {
  content: '';
  position: absolute;
  bottom: 0.25rem;
  left: 0;
  right: 0;
  height: 0.5rem;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
  opacity: 0.3;
  border-radius: var(--radius-sm);
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  line-height: 1.6;
}

.hero-stats {
  display: flex;
  gap: 2rem;
  margin-bottom: 2rem;
}

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

.stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-color);
  line-height: 1;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

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

.speed-demo {
  background-color: var(--bg-card);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--border-color);
}

.demo-card {
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1rem;
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.demo-card:last-child {
  margin-bottom: 0;
}

.demo-card.highlight {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: var(--text-inverse);
  border-color: transparent;
  transform: scale(1.05);
}

.demo-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.demo-title {
  font-weight: 600;
  font-size: 1.125rem;
}

.demo-speed {
  font-size: 0.875rem;
  opacity: 0.8;
}

.demo-progress {
  height: 0.5rem;
  background-color: rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  border-radius: var(--radius-sm);
  animation: progress 3s ease-in-out infinite;
}

.progress-bar.slow {
  background-color: var(--text-secondary);
  animation-duration: 6s;
}

.progress-bar.fast {
  background: linear-gradient(90deg, #ffffff, rgba(255, 255, 255, 0.8));
  animation-duration: 1s;
}

@keyframes progress {
  0% { width: 0%; }
  50% { width: 100%; }
  100% { width: 0%; }
}

/* 功能特色 */
.features {
  padding: 5rem 0;
  background-color: var(--bg-secondary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.feature-card {
  background-color: var(--bg-card);
  padding: 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  text-align: center;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
  transform: scaleX(0);
  transition: var(--transition);
}

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

.feature-card:hover::before {
  transform: scaleX(1);
}

.feature-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  display: block;
}

.feature-card h3 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.feature-card p {
  color: var(--text-secondary);
  line-height: 1.6;
}


/* 关于我们 */
.about {
  padding: 5rem 0;
  background-color: var(--bg-secondary);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.about-text h2 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
}

.about-text p {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.5rem;
}

.about-stats {
  display: flex;
  gap: 2rem;
  margin-top: 2rem;
}

.stat {
  text-align: center;
}

.stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-color);
  line-height: 1;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

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

.tech-item {
  background-color: var(--bg-card);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  text-align: center;
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.tech-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.tech-icon {
  font-size: 2rem;
  margin-bottom: 0.5rem;
  display: block;
}

.tech-name {
  font-weight: 500;
  color: var(--text-primary);
}

/* 极简页脚 */
.simple-footer {
  padding: 2rem 1rem;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.875rem;
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
}

.simple-footer p {
  margin: 0.25rem 0;
}

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

.simple-footer a:hover {
  text-decoration: underline;
}

/* 模态框 */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--bg-modal);
  z-index: 2000;
  backdrop-filter: blur(4px);
}

.modal.active {
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.3s ease-out;
}

.modal-content {
  background-color: var(--bg-card);
  border-radius: var(--radius-xl);
  max-width: 500px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
  animation: slideIn 0.3s ease-out;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
}

.modal-close {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 0.25rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.modal-close:hover {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
}

.modal-body {
  padding: 1.5rem;
}

.modal-body p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.input-group {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.form-input {
  flex: 1;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 1rem;
  transition: var(--transition);
}

.form-input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.error-message {
  color: var(--error-color);
  font-size: 0.875rem;
  margin-top: 0.5rem;
  display: none;
}

.error-message.show {
  display: block;
}

.modal-footer {
  text-align: center;
  margin-top: 1rem;
}

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

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

.help-text a:hover {
  text-decoration: underline;
}

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

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(-20px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* 响应式设计 */
@media (max-width: 1024px) {
  .hero-container {
    grid-template-columns: 1fr;
    gap: 2rem;
    text-align: center;
  }
  
  .about-content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .hero-stats {
    justify-content: center;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .section-header h2 {
    font-size: 2rem;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  
  .pricing-card.featured {
    transform: none;
  }
  
  .about-stats {
    justify-content: center;
  }
  
  .tech-stack {
    grid-template-columns: 1fr;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 0.5rem;
  }
  
  .hero {
    padding: 2rem 0;
  }
  
  .hero-title {
    font-size: 2rem;
  }
  
  .hero-stats {
    flex-direction: column;
    gap: 1rem;
  }
  
  .hero-actions {
    flex-direction: column;
    align-items: center;
  }
  
  .btn {
    width: 100%;
    max-width: 200px;
  }
  
  .speed-demo {
    padding: 1rem;
  }
  
  .demo-card {
    padding: 1rem;
  }
  
  .features,
  .pricing,
  .about {
    padding: 3rem 0;
  }
  
  .feature-card,
  .pricing-card {
    padding: 1.5rem;
  }
  
  .about-stats {
    flex-direction: column;
    gap: 1rem;
  }
}