:root {
      --primary: #165DFF;
      --primary-light: #4080FF;
      --primary-dark: #0E42D2;
      --secondary: #36CBCB;
      --accent: #722ED1;
      --neutral-100: #F5F7FA;
      --neutral-200: #E4E7ED;
      --neutral-300: #C0C6CF;
      --neutral-700: #4E5969;
      --neutral-800: #272E3B;
      --neutral-900: #1D2129;
      --success: #52C41A;
      --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
      --shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
      --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
      --radius-sm: 8px;
      --radius: 12px;
      --radius-lg: 20px;
      --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

    body {
      font-family: 'Inter', sans-serif;
      color: var(--neutral-800);
      background-color: #FFFFFF;
      scroll-behavior: smooth;
    }

    .section {
      padding: 80px 0;
      position: relative;
    }

    @media (max-width: 768px) {
      .section {
        padding: 60px 0;
      }
    }

    .section-title {
      font-size: clamp(1.75rem, 3vw, 2.5rem);
      font-weight: 700;
      color: var(--neutral-900);
      margin-bottom: 16px;
      position: relative;
      display: inline-block;
    }

    .section-title::after {
      content: '';
      position: absolute;
      bottom: -8px;
      left: 0;
      width: 60px;
      height: 4px;
      background-color: var(--primary);
      border-radius: 2px;
    }

    .section-subtitle {
      font-size: 1.1rem;
      color: var(--neutral-700);
      max-width: 800px;
      margin-bottom: 40px;
    }

    /* 导航栏样式 */
    .navbar {
      background-color: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(8px);
      box-shadow: var(--shadow-sm);
      padding: 0.8rem 0;
      transition: var(--transition);
    }

    .navbar-scrolled {
      padding: 0.5rem 0;
      box-shadow: var(--shadow);
    }

    .navbar-brand {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .navbar-nav .nav-link {
      color: var(--neutral-800);
      font-weight: 500;
      padding: 0.8rem 1rem;
      margin: 0 0.3rem;
      border-radius: var(--radius-sm);
      transition: var(--transition);
    }

    .navbar-nav .nav-link:hover,
    .navbar-nav .nav-link.active {
      color: var(--primary);
      background-color: rgba(22, 93, 255, 0.05);
    }

    .btn-primary {
      background-color: var(--primary);
      border-color: var(--primary);
      color: white;
      font-weight: 600;
      padding: 0.7rem 1.5rem;
      border-radius: var(--radius-sm);
      transition: var(--transition);
      box-shadow: 0 4px 12px rgba(22, 93, 255, 0.2);
    }

    .btn-primary:hover {
      background-color: var(--primary-dark);
      border-color: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(22, 93, 255, 0.3);
    }

    /* 英雄区域 */
    .hero {
      padding: 120px 0 80px;
      background: linear-gradient(135deg, #F8FAFF 0%, #EEF2FF 100%);
      overflow: hidden;
    }

    .hero-content {
      max-width: 600px;
      z-index: 1;
    }

    .hero-title {
      font-size: clamp(2rem, 5vw, 3.5rem);
      font-weight: 700;
      color: var(--neutral-900);
      line-height: 1.2;
      margin-bottom: 24px;
    }

    .hero-title span {
      color: var(--primary);
    }

    .hero-desc {
      font-size: 1.15rem;
      color: var(--neutral-700);
      line-height: 1.6;
      margin-bottom: 32px;
    }

    .hero-image {
      position: relative;
      z-index: 1;
    }

    .hero-image img {
      max-width: 100%;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-lg);
      animation: float 6s ease-in-out infinite;
    }

    @keyframes float {
      0% { transform: translateY(0px); }
      50% { transform: translateY(-15px); }
      100% { transform: translateY(0px); }
    }

    .hero-shape {
      position: absolute;
      top: 50%;
      right: 0;
      transform: translateY(-50%);
      width: 600px;
      height: 600px;
      background: radial-gradient(circle, rgba(22, 93, 255, 0.1) 0%, rgba(22, 93, 255, 0) 70%);
      border-radius: 50%;
      z-index: 0;
    }

    /* 产品特性 */
    .feature-card {
      background-color: white;
      border-radius: var(--radius);
      padding: 30px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid var(--neutral-200);
      height: 100%;
    }

    .feature-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow);
      border-color: var(--primary-light);
    }

    .feature-icon {
      width: 60px;
      height: 60px;
      border-radius: 12px;
      background-color: rgba(22, 93, 255, 0.1);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      transition: var(--transition);
    }

    .feature-card:hover .feature-icon {
      background-color: var(--primary);
    }

    .feature-icon i {
      font-size: 1.8rem;
      color: var(--primary);
      transition: var(--transition);
    }

    .feature-card:hover .feature-icon i {
      color: white;
    }

    .feature-title {
      font-size: 1.3rem;
      font-weight: 600;
      margin-bottom: 12px;
      color: var(--neutral-900);
    }

    .feature-desc {
      color: var(--neutral-700);
      line-height: 1.6;
    }

    /* 临床数据 */
    .clinical-data {
      background-color: var(--neutral-100);
    }

    .data-card {
      background-color: white;
      border-radius: var(--radius);
      padding: 30px;
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: var(--transition);
    }

    .data-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow);
    }

    .data-value {
      font-size: clamp(1.8rem, 4vw, 2.5rem);
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 8px;
    }

    .data-label {
      color: var(--neutral-700);
      font-size: 1rem;
    }

    .chart-container {
      background-color: white;
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: var(--shadow-sm);
    }

    /* 用法用量 */
    .usage-steps {
      position: relative;
    }

    .usage-steps::before {
      content: '';
      position: absolute;
      top: 0;
      bottom: 0;
      left: 30px;
      width: 2px;
      background-color: var(--primary-light);
      opacity: 0.3;
    }

    .usage-step {
      position: relative;
      padding-left: 70px;
      margin-bottom: 40px;
    }

    .usage-step:last-child {
      margin-bottom: 0;
    }

    .step-number {
      position: absolute;
      left: 0;
      top: 0;
      width: 60px;
      height: 60px;
      border-radius: 50%;
      background-color: var(--primary);
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      font-weight: 700;
      box-shadow: 0 4px 12px rgba(22, 93, 255, 0.2);
    }

    .step-title {
      font-size: 1.2rem;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--neutral-900);
    }

    .step-desc {
      color: var(--neutral-700);
      line-height: 1.6;
    }

    /* 常见问题 */
    .faq-item {
      margin-bottom: 16px;
      border-radius: var(--radius-sm);
      overflow: hidden;
      border: 1px solid var(--neutral-200);
      transition: var(--transition);
    }

    .faq-item:hover {
      box-shadow: var(--shadow-sm);
    }

    .faq-question {
      width: 100%;
      padding: 16px 20px;
      text-align: left;
      background-color: white;
      border: none;
      font-weight: 600;
      color: var(--neutral-900);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      transition: var(--transition);
    }

    .faq-question:hover {
      background-color: var(--neutral-100);
    }

    .faq-question.active {
      background-color: rgba(22, 93, 255, 0.05);
      color: var(--primary);
    }

    .faq-icon {
      transition: var(--transition);
    }

    .faq-question.active .faq-icon {
      transform: rotate(180deg);
    }

    .faq-answer {
      padding: 0 20px;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background-color: white;
    }

    .faq-answer.show {
      padding: 0 20px 20px;
      max-height: 500px;
    }

    .faq-answer p {
      color: var(--neutral-700);
      line-height: 1.6;
      margin-bottom: 0;
    }

    /* 联系咨询 */
    .contact {
      background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
      color: white;
    }

    .contact .section-title {
      color: white;
    }

    .contact .section-title::after {
      background-color: white;
    }

    .contact .section-subtitle {
      color: rgba(255, 255, 255, 0.8);
    }

    .contact-form {
      background-color: white;
      border-radius: var(--radius);
      padding: 40px;
      box-shadow: var(--shadow-lg);
    }

    .form-control {
      padding: 12px 16px;
      border-radius: var(--radius-sm);
      border: 1px solid var(--neutral-200);
      transition: var(--transition);
    }

    .form-control:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(22, 93, 255, 0.1);
      outline: none;
    }

    /* 页脚 */
    .footer {
      background-color: var(--neutral-900);
      color: rgba(255, 255, 255, 0.7);
      padding: 60px 0 20px;
    }

    .footer-logo {
      font-size: 1.5rem;
      font-weight: 700;
      color: white;
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .footer-desc {
      margin-bottom: 24px;
      line-height: 1.6;
    }

    .footer-title {
      font-size: 1.1rem;
      font-weight: 600;
      color: white;
      margin-bottom: 20px;
    }

    .footer-links {
      list-style: none;
      padding: 0;
      margin: 0;
    }

    .footer-links li {
      margin-bottom: 12px;
    }

    .footer-links a {
      color: rgba(255, 255, 255, 0.7);
      text-decoration: none;
      transition: var(--transition);
    }

    .footer-links a:hover {
      color: white;
      padding-left: 4px;
    }

    .footer-bottom {
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid rgba(255, 255, 255, 0.1);
      text-align: center;
      font-size: 0.9rem;
    }

    /* 免责声明 */
    .disclaimer {
      background-color: var(--neutral-100);
      padding: 20px 0;
      font-size: 0.85rem;
      color: var(--neutral-700);
    }

    .disclaimer p {
      margin-bottom: 0;
      text-align: center;
    }

    /* 动画效果 */
    .fade-in {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }

    .fade-in.visible {
      opacity: 1;
      transform: translateY(0);
    }

    /* 响应式调整 */
    @media (max-width: 992px) {
      .hero {
        padding: 80px 0 60px;
      }
      
      .hero-shape {
        width: 400px;
        height: 400px;
      }
      
      .contact-form {
        padding: 30px;
      }
    }

    @media (max-width: 768px) {
      .navbar-collapse {
        background-color: white;
        border-radius: var(--radius);
        box-shadow: var(--shadow);
        padding: 1rem;
        margin-top: 0.5rem;
      }
      
      .navbar-nav .nav-link {
        padding: 0.6rem 1rem;
        margin: 0.2rem 0;
      }
      
      .hero-title {
        font-size: clamp(1.8rem, 4vw, 2.5rem);
      }
      
      .hero-image {
        margin-top: 40px;
      }
      
      .usage-steps::before {
        left: 25px;
      }
      
      .usage-step {
        padding-left: 60px;
      }
      
      .step-number {
        width: 50px;
        height: 50px;
        font-size: 1.2rem;
      }
    }

    @media (max-width: 576px) {
      .section {
        padding: 40px 0;
      }
      
      .hero {
        padding: 60px 0 40px;
      }
      
      .feature-card {
        padding: 20px;
      }
      
      .contact-form {
        padding: 20px;
      }
      
      .footer {
        padding: 40px 0 20px;
      }
    }