:root {
    --bg-color: #f7f4f0;
    --card-bg: #ffffff;
    --text-main: #2c2523;
    --text-muted: #736565;
    --brand-color: #c93b3b;
    --brand-hover: #a82d2d;
    --brand-light: #fceeee;
    --border-color: #e8e0d8;
    --radius-lg: 20px;
    --radius-md: 12px;
    --radius-sm: 8px;
    --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
    --shadow-md: 0 8px 24px rgba(201, 59, 59, 0.08);
  }

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

  body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
  }

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

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

  /* 布局容器 */
  .container {
    width: 100%;
    max-width: 1024px;
    margin: 0 auto;
    padding: 0 20px;
  }

  /* 顶部导航 */
  header {
    padding: 16px 0;
    background: rgba(247, 244, 240, 0.9);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
  }
  .header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
  }
  .logo-area {
    display: flex;
    align-items: center;
    gap: 10px;
  }
  .logo-area img {
    height: 32px;
    width: auto;
    border-radius: 6px;
  }
  .logo-area span {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-main);
    letter-spacing: 1px;
  }
  .header-cta {
    font-size: 14px;
    background: var(--brand-color);
    color: #fff;
    padding: 8px 18px;
    border-radius: 30px;
    font-weight: 500;
    transition: background 0.2s;
  }
  .header-cta:hover {
    background: var(--brand-hover);
  }

  /* 首屏主标题 */
  .hero {
    text-align: center;
    padding: 60px 0 40px;
  }
  .hero h1 {
    font-size: 28px;
    line-height: 1.3;
    color: var(--text-main);
    margin-bottom: 16px;
    font-weight: 800;
  }
  .hero p {
    font-size: 16px;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 30px;
  }
  .btn-primary {
    display: inline-block;
    background: var(--brand-color);
    color: #fff;
    font-size: 18px;
    font-weight: 600;
    padding: 14px 40px;
    border-radius: 40px;
    box-shadow: var(--shadow-md);
    transition: transform 0.2s, background 0.2s;
  }
  .btn-primary:hover {
    background: var(--brand-hover);
    transform: translateY(-2px);
  }

  /* 通用区块标题 */
  .section-title {
    text-align: center;
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 8px;
    margin-top: 60px;
  }
  .section-subtitle {
    text-align: center;
    font-size: 15px;
    color: var(--text-muted);
    margin-bottom: 30px;
  }

  /* 角色广场（卡片网格） */
  .role-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  .role-card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: transform 0.2s, box-shadow 0.2s;
  }
  .role-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
  }
  .role-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    object-position: top;
  }
  .role-info {
    padding: 12px 14px;
  }
  .role-tag {
    display: inline-block;
    font-size: 11px;
    background: var(--brand-light);
    color: var(--brand-color);
    padding: 2px 8px;
    border-radius: 4px;
    margin-bottom: 6px;
  }
  .role-info h3 {
    font-size: 16px;
    margin-bottom: 4px;
    color: var(--text-main);
  }
  .role-info p {
    font-size: 12px;
    color: var(--text-muted);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }

  /* 角色互动演示 */
  .demo-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 24px 20px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
  }
  .demo-chat {
    background: var(--bg-color);
    border-radius: var(--radius-md);
    padding: 16px;
    margin-bottom: 20px;
  }
  .chat-bubble {
    max-width: 85%;
    padding: 10px 14px;
    border-radius: 12px;
    font-size: 14px;
    line-height: 1.5;
    margin-bottom: 10px;
    position: relative;
  }
  .chat-bubble.ai {
    background: var(--brand-light);
    color: var(--text-main);
    border-bottom-left-radius: 2px;
  }
  .chat-bubble.user {
    background: var(--brand-color);
    color: #fff;
    margin-left: auto;
    border-bottom-right-radius: 2px;
  }
  .demo-points {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .demo-point-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
  }
  .demo-point-icon {
    background: var(--brand-light);
    color: var(--brand-color);
    border-radius: 50%;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: bold;
    flex-shrink: 0;
    margin-top: 2px;
  }
  .demo-point-item div h4 {
    font-size: 15px;
    margin-bottom: 2px;
  }
  .demo-point-item div p {
    font-size: 13px;
    color: var(--text-muted);
  }

  /* 创作者中心 */
  .creator-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .creator-item {
    background: var(--card-bg);
    border-radius: var(--radius-md);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
  }
  .creator-item h3 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--brand-color);
  }
  .creator-item p {
    font-size: 14px;
    color: var(--text-muted);
  }

  /* 多模型切换与API */
  .api-section {
    background: var(--text-main);
    color: #fff;
    border-radius: var(--radius-lg);
    padding: 30px 20px;
    margin-top: 40px;
  }
  .api-section h2 {
    text-align: center;
    font-size: 22px;
    margin-bottom: 12px;
  }
  .api-section p {
    text-align: center;
    font-size: 14px;
    color: #d1c9c5;
    margin-bottom: 20px;
  }
  .api-feature-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
  }
  .api-feature-list li {
    background: rgba(255,255,255,0.08);
    border-radius: var(--radius-sm);
    padding: 12px 16px;
    font-size: 14px;
    list-style: none;
    display: flex;
    align-items: center;
    gap: 10px;
  }
  .api-feature-list li::before {
    content: "✦";
    color: var(--brand-color);
    font-weight: bold;
  }

  /* 用户评价 */
  .review-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .review-card {
    background: var(--card-bg);
    border-radius: var(--radius-md);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
  }
  .review-card p {
    font-size: 14px;
    color: var(--text-main);
    font-style: italic;
    margin-bottom: 12px;
  }
  .review-author {
    display: flex;
    align-items: center;
    gap: 10px;
  }
  .review-avatar {
    width: 32px;
    height: 32px;
    background: var(--brand-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--brand-color);
    font-weight: bold;
    font-size: 14px;
  }
  .review-author span {
    font-size: 13px;
    color: var(--text-muted);
  }

  /* 安全隐私 */
  .safety-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 24px 20px;
    margin-top: 40px;
    border: 1px solid var(--border-color);
  }
  .safety-section h2 {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--text-main);
  }
  .safety-section p {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 12px;
  }

  /* FAQ */
  .faq-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
  }
  .faq-item {
    background: var(--card-bg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
  }
  .faq-question {
    padding: 16px;
    font-weight: 600;
    font-size: 15px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--card-bg);
  }
  .faq-question::after {
    content: "+";
    font-size: 20px;
    color: var(--brand-color);
    transition: transform 0.2s;
  }
  .faq-item.active .faq-question::after {
    content: "-";
    transform: rotate(180deg);
  }
  .faq-answer {
    padding: 0 16px 16px;
    font-size: 14px;
    color: var(--text-muted);
    display: block;
  }

  /* 结尾CTA */
  .final-cta {
    text-align: center;
    padding: 50px 20px;
    background: linear-gradient(135deg, var(--brand-light) 0%, #fff 100%);
    border-radius: var(--radius-lg);
    margin: 40px 0;
    border: 1px solid var(--brand-light);
  }
  .final-cta h2 {
    font-size: 24px;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 20px;
  }
  .final-cta .btn-primary {
    font-size: 18px;
    padding: 16px 40px;
  }

  /* 页脚 */
  footer {
    text-align: center;
    padding: 30px 20px;
    border-top: 1px solid var(--border-color);
    margin-top: 20px;
  }
  footer p {
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 6px;
  }
  footer time {
    font-size: 12px;
    color: #a09491;
  }

  /* 响应式断点 */
  @media (min-width: 768px) {
    .hero h1 {
      font-size: 36px;
    }
    .hero p {
      font-size: 18px;
    }
    .role-grid {
      grid-template-columns: repeat(3, 1fr);
    }
    .role-card img {
      height: 240px;
    }
    .demo-points {
      grid-template-columns: repeat(2, 1fr);
    }
    .creator-grid {
      grid-template-columns: repeat(3, 1fr);
    }
    .review-grid {
      grid-template-columns: repeat(2, 1fr);
    }
    .api-feature-list {
      flex-direction: row;
      flex-wrap: wrap;
      justify-content: center;
    }
    .api-feature-list li {
      width: calc(50% - 6px);
    }
    .section-title {
      font-size: 28px;
      margin-top: 80px;
    }
  }

  @media (min-width: 1024px) {
    .role-grid {
      grid-template-columns: repeat(4, 1fr);
    }
    .demo-points {
      grid-template-columns: repeat(3, 1fr);
    }
    .creator-item {
      padding: 28px 24px;
    }
  }