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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
      background: #f5f7fb;
      color: #222;
      line-height: 1.7;
    }

    a {
      text-decoration: none;
      color: inherit;
    }

    .topbar {
      background: #fff;
      border-bottom: 1px solid #eee;
      padding: 10px 0;
    }

    .container {
      width: 1200px;
      max-width: 95%;
      margin: auto;
    }

    .topbar-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 14px;
      color: #666;
    }

    .logo-area {
      display: flex;
      align-items: center;
      gap: 15px;
      padding: 25px 0;
    }

    .logo {
      width: 70px;
      height: 70px;
      border-radius: 50%;
      
      display: flex;
      align-items: center;
      justify-content: center;
      color: #fff;
      font-size: 28px;
      font-weight: bold;
    }

    .brand h1 {
      font-size: 34px;
      color: #111827;
      margin-bottom: 6px;
    }

    .brand p {
      color: #64748b;
      font-size: 15px;
    }

    .phone {
      margin-left: auto;
      font-size: 36px;
      color: #dc2626;
      font-weight: bold;
    }

    nav {
      background: linear-gradient(90deg,#0284c7,#2563eb);
      box-shadow: 0 2px 10px rgba(0,0,0,.08);
    }

    .nav-menu {
      display: flex;
      flex-wrap: wrap;
      list-style: none;
    }

    .nav-menu li a {
      display: block;
      padding: 16px 22px;
      color: #fff;
      font-weight: 500;
      transition: .3s;
    }

    .nav-menu li a:hover {
      background: rgba(255,255,255,.12);
    }

    .main {
      display: grid;
      grid-template-columns: 280px 1fr;
      gap: 25px;
      margin-top: 25px;
      margin-bottom: 40px;
    }

    .sidebar,
    .content-box {
      background: #fff;
      border-radius: 12px;
      box-shadow: 0 5px 20px rgba(0,0,0,.05);
      overflow: hidden;
    }

    .sidebar-section h2,
    .content-header h2 {
      background: linear-gradient(90deg,#eff6ff,#dbeafe);
      padding: 16px 20px;
      font-size: 18px;
      color: #1e3a8a;
      border-bottom: 1px solid #e5e7eb;
    }

    .sidebar-links {
      list-style: none;
      padding: 10px 0;
    }

    .sidebar-links li a {
      display: block;
      padding: 12px 20px;
      color: #334155;
      border-left: 3px solid transparent;
      transition: .3s;
    }

    .sidebar-links li a:hover {
      background: #f8fafc;
      border-left-color: #2563eb;
      color: #2563eb;
    }

    .hero {
      padding: 35px;
      background: linear-gradient(135deg,#0f172a,#1e40af);
      color: #fff;
    }

    .hero h2 {
      font-size: 36px;
      margin-bottom: 15px;
      line-height: 1.4;
    }

    .hero p {
      font-size: 16px;
      color: rgba(255,255,255,.85);
      margin-bottom: 20px;
    }

    .hero-buttons {
      display: flex;
      gap: 15px;
      flex-wrap: wrap;
    }

    .btn {
      padding: 12px 24px;
      border-radius: 8px;
      font-weight: 600;
      transition: .3s;
    }

    .btn-primary {
      background: #fff;
      color: #1e3a8a;
    }

    .btn-secondary {
      border: 1px solid rgba(255,255,255,.3);
      color: #fff;
    }

    .btn:hover {
      transform: translateY(-2px);
    }

    .section {
      padding: 30px;
      border-bottom: 1px solid #f1f5f9;
    }

    .section h2 {
      font-size: 28px;
      margin-bottom: 20px;
      color: #0f172a;
    }

    .section h3 {
      font-size: 22px;
      margin-bottom: 15px;
      color: #1d4ed8;
    }

    .grid {
      display: grid;
      grid-template-columns: repeat(auto-fit,minmax(240px,1fr));
      gap: 20px;
    }

    .card {
      background: #fff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 22px;
      transition: .3s;
    }

    .card:hover {
      transform: translateY(-4px);
      box-shadow: 0 10px 30px rgba(37,99,235,.12);
      border-color: #93c5fd;
    }

    .card h3 {
      font-size: 20px;
      margin-bottom: 10px;
      color: #0f172a;
    }

    .card p {
      color: #64748b;
      font-size: 14px;
    }

    .faq-item {
      margin-bottom: 25px;
      padding-bottom: 20px;
      border-bottom: 1px dashed #cbd5e1;
    }

    .faq-item h3 {
      margin-bottom: 10px;
      color: #1e3a8a;
    }

    footer {
      background: #0f172a;
      color: rgba(255,255,255,.75);
      padding: 50px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit,minmax(220px,1fr));
      gap: 30px;
    }

    .footer-col h3 {
      color: #fff;
      margin-bottom: 16px;
      font-size: 18px;
    }

    .footer-col a {
      display: block;
      margin-bottom: 10px;
      color: rgba(255,255,255,.7);
      font-size: 14px;
    }

    .copyright {
      text-align: center;
      margin-top: 35px;
      padding-top: 20px;
      border-top: 1px solid rgba(255,255,255,.08);
      font-size: 13px;
    }

    @media (max-width: 960px) {
      .main {
        grid-template-columns: 1fr;
      }

      .phone {
        font-size: 24px;
      }

      .hero h2 {
        font-size: 28px;
      }
    }

    @media (max-width: 640px) {
      .topbar {
        display: none;
      }

      .logo-area {
        flex-direction: row;
        align-items: center;
        gap: 15px;
        flex-wrap: nowrap;
      }

      .logo {
        width: 60px;
        height: 60px;
        min-width: 60px;
        font-size: 24px;
      }

      .brand h1 {
        font-size: 24px;
        line-height: 1.2;
      }

      .brand p {
        font-size: 13px;
        line-height: 1.6;
      }

      .phone {
        display: none;
      }

      .nav-menu {
        overflow-x: auto;
        white-space: nowrap;
        flex-wrap: nowrap;
      }

      .nav-menu li a {
        padding: 12px 14px;
        font-size: 14px;
      }

      .hero {
        padding: 25px;
      }

      .hero h2 {
        font-size: 24px;
      }

      .section {
        padding: 22px;
      }

      .sidebar-links {
        display: none;
      }

      .sidebar-section.active .sidebar-links {
        display: block;
      }

      .sidebar-section h2 {
        position: relative;
        cursor: pointer;
        padding-right: 50px;
      }

      .sidebar-section h2::after {
        content: "+";
        position: absolute;
        right: 20px;
        top: 50%;
        transform: translateY(-50%);
        font-size: 24px;
        color: #2563eb;
      }

      .sidebar-section.active h2::after {
        content: "−";
      }

      .footer-grid {
        grid-template-columns: repeat(2,1fr);
        gap: 20px;
      }

      .footer-col {
        width: 100%;
      }
    }