/* 基础样式 */
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  .video-page {
    max-width: 1280px;
    margin: 2rem auto;
    background: #ffffff;
    border-radius: 2rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
    overflow: hidden;
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    color: #1e293b;
    line-height: 1.5;
  }
  .content-padding {
    padding-left: 2rem;
    padding-right: 2rem;
  }
  h1 {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
    background: linear-gradient(145deg, #0b2b4a, #153e5a);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
  }
  /* 视频容器 */
  .video-wrapper {
    position: relative;
    width: 100%;
    background: #0b1a2a;
    margin: 1.5rem 0 2rem;
    padding-bottom: 56.25%;
  }
  .video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 0;
  }
  /* 按钮组 */
  .cta-group {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.5rem;
    margin: 2rem 0 3rem;
  }
  .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2.8rem;
    border-radius: 60px;
    font-weight: 600;
    font-size: 1.2rem;
    text-decoration: none;
    transition: all 0.25s ease;
    border: none;
    gap: 0.75rem;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
  }
  .btn-primary {
    background: linear-gradient(145deg, #f15a24, #d94b1a);
    color: white;
    box-shadow: 0 12px 24px -8px #f15a24cc;
  }
  .btn-primary:hover {
    background: linear-gradient(145deg, #e04e1a, #c03f12);
    transform: translateY(-4px);
    box-shadow: 0 20px 28px -8px #f15a24;
  }
  .btn-secondary {
    background: white;
    color: #153e5a;
    border: 2px solid #153e5a;
    box-shadow: 0 8px 16px rgba(21, 62, 90, 0.1);
  }
  .btn-secondary:hover {
    background: #f0f7ff;
    border-color: #0e2c40;
    color: #0e2c40;
    transform: translateY(-4px);
    box-shadow: 0 16px 24px -8px #153e5a80;
  }
  /* 技术亮点 + 专家区块 */
  .spec-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    background: #f9fcff;
    border-radius: 32px;
    padding: 2rem;
    margin: 2.5rem 0;
  }
  .feature-list {
    list-style: none;
  }
  .feature-list li {
    margin-bottom: 1rem;
    font-size: 1.05rem;
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
  }
  .feature-list li::before {
    content: "▹";
    color: #f15a24;
    font-weight: bold;
    font-size: 1.3rem;
    line-height: 1;
  }
  .expert-card {
    background: white;
    padding: 1.5rem;
    border-radius: 24px;
    box-shadow: 0 6px 18px rgba(0, 30, 60, 0.05);
    border: 1px solid #e2edf7;
  }
  .expert-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #0b2b4a;
    margin-bottom: 0.75rem;
  }
  .badge-group {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin: 1rem 0;
  }
  .badge {
    background: #e2edf7;
    padding: 0.3rem 1rem;
    border-radius: 40px;
    font-size: 0.85rem;
    font-weight: 600;
    color: #153e5a;
  }
  .learn-section {
    background: #f3f9ff;
    border-radius: 24px;
    padding: 1.8rem;
    margin: 2rem 0 1rem;
  }
  .learn-section h3 {
    font-size: 1.6rem;
    color: #0b2b4a;
    margin-bottom: 1rem;
  }
  .learn-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1rem;
  }
  .learn-grid div {
    background: white;
    padding: 1rem;
    border-radius: 18px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.02);
  }
  .quote-reminder {
    text-align: center;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px dashed #cbd5e1;
  }
  .quote-reminder p {
    font-size: 1.2rem;
    color: #163a57;
  }
  .small-note {
    color: #617388;
    font-size: 0.9rem;
    margin-top: 0.5rem;
  }
  /* 新增：相关视频板块 */
  .related-videos {
    margin: 3rem 0 1rem;
    padding-top: 1.5rem;
    border-top: 2px solid #e9edf2;
  }
  .related-videos h2 {
    font-size: 1.8rem;
    font-weight: 600;
    color: #0b2b4a;
    margin-bottom: 1.5rem;
    text-align: center;
  }
  .related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
  }
  .related-card {
    background: #f9fcff;
    border-radius: 24px;
    padding: 1.5rem 1.2rem;
    text-decoration: none;
    color: inherit;
    transition: all 0.25s ease;
    border: 1px solid #e2edf7;
    box-shadow: 0 4px 12px rgba(0, 30, 60, 0.05);
  }
  .related-card:hover {
    background: #ffffff;
    transform: translateY(-6px);
    box-shadow: 0 20px 30px -10px rgba(21, 62, 90, 0.15);
    border-color: #cbddee;
  }
  .related-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: #153e5a;
    margin-bottom: 0.5rem;
  }
  .related-card p {
    font-size: 0.95rem;
    color: #3f5e7a;
    margin-bottom: 0;
  }
  @media (max-width: 680px) {
    h1 { font-size: 1.8rem; }
    .btn { width: 100%; padding: 0.9rem 1.5rem; font-size: 1rem; }
    .cta-group { flex-direction: column; gap: 0.75rem; }
    .content-padding { padding-left: 1rem; padding-right: 1rem; }
    .spec-grid { padding: 1.5rem; }
    .related-grid { grid-template-columns: 1fr; }
  }