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

      body {
          font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
          background-color: #f9fafc;
          color: #1e293b;
          line-height: 1.5;
          scroll-behavior: smooth;
      }

      /* 鲜艳科研配色 */
      :root {
          --primary-blue: #2D6AFF;
          --primary-blue-dark: #1e4bd2;
          --accent-green: #10B981;
          --accent-orange: #F97316;
          --bg-light: #F8FAFE;
          --card-white: #FFFFFF;
          --text-dark: #0F172A;
          --text-muted: #475569;
          --border-light: #E9EEF3;
          --shadow-sm: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.02);
          --shadow-md: 0 20px 25px -5px rgba(0, 0, 0, 0.05), 0 10px 10px -5px rgba(0, 0, 0, 0.01);
      }

      .container {
          max-width: 1280px;
          margin: 0 auto;
          padding: 0 24px;
      }

      /* 导航栏 */
      .navbar {
          background: rgba(255,255,255,0.96);
          backdrop-filter: blur(8px);
          border-bottom: 1px solid var(--border-light);
          position: sticky;
          top: 0;
          z-index: 50;
          padding: 16px 0;
      }

      .nav-flex {
          display: flex;
          align-items: center;
          justify-content: space-between;
          flex-wrap: wrap;
          gap: 20px;
      }

      .logo {
          font-size: 1.8rem;
          font-weight: 800;
          background: linear-gradient(135deg, var(--primary-blue) 0%, var(--accent-green) 100%);
          -webkit-background-clip: text;
          background-clip: text;
          color: transparent;
          letter-spacing: -0.3px;
          text-decoration: none;
      }
      .nav-links {
          display: flex;
          gap: 32px;
          font-weight: 500;
      }
      .nav-links a {
          text-decoration: none;
          color: var(--text-dark);
          transition: color 0.2s;
      }
      .nav-links a:hover {
          color: var(--primary-blue);
      }
      .btn-primary {
          background: var(--primary-blue);
          color: white;
          padding: 10px 24px;
          border-radius: 40px;
          font-weight: 600;
          border: none;
          cursor: pointer;
          transition: all 0.2s ease;
          text-decoration: none;
          display: inline-block;
          box-shadow: 0 2px 6px rgba(45,106,255,0.2);
      }
      .btn-primary:hover {
          background: var(--primary-blue-dark);
          transform: translateY(-1px);
      }
      .btn-outline {
          border: 1.5px solid var(--primary-blue);
          background: transparent;
          color: var(--primary-blue);
          padding: 8px 22px;
          border-radius: 40px;
          font-weight: 600;
          transition: 0.2s;
          text-decoration: none;
          display: inline-block;
      }
      .btn-outline:hover {
          background: var(--primary-blue);
          color: white;
      }

      /* 页面头部 */
      .page-header {
          background: linear-gradient(135deg, #EFF6FF 0%, #FFFFFF 100%);
          padding: 64px 0 48px;
          text-align: center;
      }
      .page-header h1 {
          font-size: 3rem;
          font-weight: 800;
          background: linear-gradient(to right, #0F2B5E, var(--primary-blue));
          -webkit-background-clip: text;
          background-clip: text;
          color: transparent;
          margin-bottom: 20px;
      }
      .page-header p {
          font-size: 1.2rem;
          color: var(--text-muted);
          max-width: 700px;
          margin: 0 auto;
      }

      /* 通用 */
      section {
          padding: 80px 0;
      }
      .section-title {
          text-align: center;
          font-size: 2.2rem;
          font-weight: 800;
          margin-bottom: 16px;
      }
      .section-sub {
          text-align: center;
          color: var(--text-muted);
          max-width: 700px;
          margin: 0 auto 56px auto;
          font-size: 1.1rem;
      }

      /* 四步流程 - 核心视觉 */
      .steps-container {
          display: flex;
          flex-wrap: wrap;
          justify-content: center;
          gap: 30px;
          margin: 40px 0 60px;
      }
      .step-card {
          background: var(--card-white);
          border-radius: 32px;
          flex: 1;
          min-width: 240px;
          padding: 32px 24px;
          text-align: center;
          box-shadow: var(--shadow-sm);
          border: 1px solid var(--border-light);
          transition: transform 0.2s, box-shadow 0.2s;
          position: relative;
      }
      .step-card:hover {
          transform: translateY(-8px);
          box-shadow: var(--shadow-md);
      }
      .step-number-badge {
          width: 56px;
          height: 56px;
          background: var(--accent-green);
          color: white;
          font-weight: 800;
          font-size: 1.8rem;
          border-radius: 60px;
          display: flex;
          align-items: center;
          justify-content: center;
          margin: 0 auto 20px;
          box-shadow: 0 8px 16px -6px rgba(16,185,129,0.3);
      }
      .step-card h3 {
          font-size: 1.5rem;
          margin-bottom: 12px;
          font-weight: 700;
      }
      .step-card p {
          color: var(--text-muted);
          margin-bottom: 16px;
      }
      .step-icon {
          font-size: 2rem;
          color: var(--primary-blue);
          margin-bottom: 16px;
      }

      /* 操作指南双栏 */
      .guide-section {
          background: var(--bg-light);
          border-radius: 48px;
          padding: 48px;
          margin: 40px 0;
      }
      .two-columns {
          display: flex;
          flex-wrap: wrap;
          gap: 48px;
          align-items: flex-start;
      }
      .col-guide {
          flex: 1;
      }
      .col-guide h3 {
          font-size: 1.6rem;
          margin-bottom: 20px;
          color: var(--text-dark);
      }
      .spec-list {
          background: white;
          border-radius: 24px;
          padding: 24px;
          margin-top: 20px;
      }
      .spec-item {
          display: flex;
          align-items: center;
          gap: 16px;
          padding: 12px 0;
          border-bottom: 1px solid var(--border-light);
      }
      .spec-item i {
          width: 32px;
          color: var(--accent-orange);
          font-size: 1.2rem;
      }

      /* 报告示例卡片 */
      .report-preview {
          background: white;
          border-radius: 28px;
          padding: 28px;
          box-shadow: var(--shadow-sm);
          margin-top: 30px;
      }
      .badge-list {
          display: flex;
          flex-wrap: wrap;
          gap: 10px;
          margin: 16px 0;
      }
      .badge {
          background: #EFF6FF;
          padding: 6px 14px;
          border-radius: 40px;
          font-size: 0.75rem;
          font-weight: 600;
          color: var(--primary-blue);
      }

      /* 时间轴/速度展示 */
      .speed-stats {
          display: flex;
          justify-content: center;
          gap: 48px;
          flex-wrap: wrap;
          margin: 48px 0;
          text-align: center;
      }
      .speed-item {
          background: white;
          border-radius: 32px;
          padding: 24px 32px;
          min-width: 180px;
          box-shadow: var(--shadow-sm);
      }
      .speed-number {
          font-size: 2.5rem;
          font-weight: 800;
          color: var(--primary-blue);
      }

      /* 常见问题 (流程相关) */
      .faq-list {
          max-width: 900px;
          margin: 0 auto;
      }
      .faq-item {
          background: white;
          margin-bottom: 16px;
          border-radius: 20px;
          border: 1px solid var(--border-light);
          overflow: hidden;
      }
      .faq-question {
          padding: 20px 28px;
          font-weight: 700;
          font-size: 1.1rem;
          cursor: pointer;
          display: flex;
          justify-content: space-between;
          align-items: center;
          background: white;
      }
      .faq-question i {
          color: var(--primary-blue);
          transition: transform 0.2s;
      }
      .faq-answer {
          padding: 0 28px 20px 28px;
          color: var(--text-muted);
          border-top: 1px solid var(--border-light);
          display: none;
          line-height: 1.6;
      }
      .faq-item.active .faq-answer {
          display: block;
      }
      .faq-item.active .faq-question i {
          transform: rotate(180deg);
      }

      .footer {
          background: #0F172A;
          color: #94A3B8;
          padding: 48px 0 24px;
          text-align: center;
      }

      @media (max-width: 768px) {
          .page-header h1 { font-size: 2.2rem; }
          .section-title { font-size: 1.8rem; }
          .guide-section { padding: 28px; }
          .steps-container { gap: 20px; }
      }