/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --secondary: #0EA5E9;
      --accent: #F59E0B;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text: #334155;
      --text-light: #64748B;
      --dark-heading: #0F172A;
      --border: #E2E8F0;
      --success: #10B981;
      --footer-bg: #1E293B;
      --footer-text: #CBD5E1;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.12);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-img: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "Inter", "SF Pro Display", sans-serif;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: #FFFFFF;
      box-shadow: 0 1px 3px rgba(0,0,0,0.08);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
      transition: box-shadow 0.3s;
    }

    .header.scrolled {
      box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
      white-space: nowrap;
    }

    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
    }

    .nav-links a {
      font-weight: 500;
      color: var(--text);
      font-size: 0.98rem;
      position: relative;
      padding-bottom: 4px;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--secondary);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 3px;
      background: var(--secondary);
      transition: width 0.25s ease;
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .nav-cta {
      background: var(--secondary);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background 0.2s, box-shadow 0.2s;
      box-shadow: 0 4px 10px rgba(14,165,233,0.25);
      margin-left: 1rem;
    }

    .nav-cta:hover {
      background: #0284C7;
      box-shadow: 0 6px 14px rgba(14,165,233,0.35);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 2rem;
      color: var(--primary);
      cursor: pointer;
    }

    /* Hero */
    .hero {
      padding: 140px 0 80px;
      background: linear-gradient(180deg, #F8FAFC 0%, #FFFFFF 100%);
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }

    .hero-left {
      flex: 1;
    }

    .hero-left h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 700;
      color: var(--dark-heading);
      margin-bottom: 1.5rem;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-light);
      margin-bottom: 2rem;
      line-height: 1.6;
    }

    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
      align-items: center;
    }

    .btn-primary {
      background: var(--accent);
      color: #1E293B;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      display: inline-block;
      transition: background 0.2s, transform 0.1s;
      box-shadow: 0 4px 12px rgba(245,158,11,0.3);
    }

    .btn-primary:hover {
      background: #D97706;
      transform: translateY(-1px);
    }

    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      transition: all 0.2s;
    }

    .btn-secondary:hover {
      background: var(--primary);
      color: white;
    }

    .hero-note {
      margin-top: 1.2rem;
      font-size: 14px;
      color: var(--text-light);
    }

    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }

    .hero-image {
      width: 100%;
      max-width: 500px;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.08);
    }

    /* 通用区块 */
    section {
      padding: 80px 0;
    }

    .section-title {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
      text-align: center;
      margin-bottom: 16px;
      position: relative;
    }

    .section-title::after {
      content: '';
      display: block;
      width: 60px;
      height: 3px;
      background: var(--secondary);
      margin: 12px auto 32px;
    }

    .grid-3, .grid-4 {
      display: grid;
      gap: 24px;
    }

    .grid-3 {
      grid-template-columns: repeat(3, 1fr);
    }

    .grid-4 {
      grid-template-columns: repeat(4, 1fr);
    }

    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      border: 1px solid transparent;
    }

    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: #E2E8F0;
    }

    .icon-placeholder {
      width: 48px;
      height: 48px;
      color: var(--secondary);
      margin-bottom: 16px;
    }

    .card h3 {
      font-size: 22px;
      font-weight: 600;
      color: #1E293B;
      margin-bottom: 10px;
    }

    .card p {
      color: var(--text-light);
      font-size: 15px;
      line-height: 1.6;
    }

    .cover-card img {
      width: 100%;
      height: 140px;
      object-fit: cover;
      border-radius: var(--radius-img);
      margin-bottom: 16px;
    }

    .results-bg {
      background: #F0F7FA;
    }

    .stat-grid {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 2rem;
    }

    .stat-item {
      text-align: center;
      min-width: 160px;
    }

    .stat-number {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
    }

    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .testimonial-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-card);
      position: relative;
    }

    .testimonial-card::before {
      content: "“";
      font-size: 48px;
      color: var(--secondary);
      opacity: 0.2;
      position: absolute;
      top: 10px;
      left: 20px;
      font-family: serif;
    }

    .faq-container {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }

    .faq-question {
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: #1E293B;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      color: var(--text-light);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }

    .faq-item.active {
      background: #F0F7FA;
      margin: 0 -16px;
      padding-left: 16px;
      padding-right: 16px;
      border-radius: 8px;
    }

    .cta-section {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 80px 0;
    }

    .cta-section h2 {
      color: white;
      font-size: 36px;
    }

    .cta-section .btn-primary {
      background: var(--accent);
      color: #1E293B;
      margin-top: 24px;
    }

    .footer {
      background: var(--footer-bg);
      color: var(--footer-text);
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }

    .footer a {
      color: #CBD5E1;
      display: block;
      margin-bottom: 8px;
    }

    .footer a:hover {
      color: white;
    }

    .copyright {
      text-align: center;
      margin-top: 40px;
      font-size: 14px;
      color: #94A3B8;
    }

    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .testimonial-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .header { height: 60px; }
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      .hero-grid { flex-direction: column; }
      .hero-left h1 { font-size: 32px; }
      .grid-3, .grid-4, .testimonial-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero { padding: 100px 0 60px; }
    }