/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-hover: #134B62;
      --accent: #F15A24;
      --accent-hover: #D94A1A;
      --bg-light: #F7F9FC;
      --card-white: #FFFFFF;
      --text-dark: #1E293B;
      --text-muted: #64748B;
      --border-light: #E2E8F0;
      --success: #10B981;
      --gradient-hero: linear-gradient(135deg, #1A5F7A 0%, #0F3D52 100%);
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.10);
      --radius: 12px;
      --radius-btn: 8px;
      --container: 1200px;
      --nav-height: 72px;
      --space-section: 100px;
      --space-mobile: 60px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 20px;
    }
    /* 导航 */
    #nav {
      position: sticky;
      top: 0;
      z-index: 100;
      background: var(--card-white);
      height: var(--nav-height);
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
      transition: box-shadow 0.2s;
    }
    #nav.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }
    .logo {
      display: flex;
      align-items: baseline;
      gap: 8px;
      text-decoration: none;
      color: var(--primary);
    }
    .logo-text {
      font-size: 1.7rem;
      font-weight: 700;
      letter-spacing: 1px;
    }
    .logo-domain {
      font-size: 0.75rem;
      font-weight: 400;
      color: var(--text-muted);
      letter-spacing: 0.3px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 36px;
      list-style: none;
    }
    .nav-links a {
      text-decoration: none;
      font-weight: 500;
      color: var(--text-dark);
      font-size: 0.95rem;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a:focus-visible {
      color: var(--primary);
      outline: none;
    }
    .nav-cta {
      background: var(--accent);
      color: white !important;
      padding: 10px 20px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background 0.2s, transform 0.2s;
      white-space: nowrap;
    }
    .nav-cta:hover {
      background: var(--accent-hover);
      transform: translateY(-1px);
      color: white !important;
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      background: none;
      border: none;
      color: var(--text-dark);
      cursor: pointer;
      padding: 8px;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: var(--primary);
      display: none;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 30px;
      z-index: 99;
      opacity: 0;
      transform: translateY(-10px);
      transition: opacity 0.3s ease, transform 0.3s ease;
      pointer-events: none;
    }
    .mobile-menu.active {
      display: flex;
      opacity: 1;
      transform: translateY(0);
      pointer-events: auto;
    }
    .mobile-menu a {
      color: white;
      font-size: 1.6rem;
      text-decoration: none;
      font-weight: 500;
    }
    .mobile-menu .nav-cta {
      background: var(--accent);
      font-size: 1.3rem;
      padding: 12px 32px;
    }
    /* Hero */
    #hero {
      background: var(--gradient-hero);
      color: white;
      padding: 80px 0;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 50px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.2rem;
    }
    .hero-sub {
      font-size: 1.15rem;
      color: rgba(255,255,255,0.85);
      margin-bottom: 2.5rem;
      max-width: 450px;
    }
    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 20px;
    }
    .btn {
      display: inline-block;
      font-weight: 600;
      padding: 14px 30px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      transition: all 0.2s ease;
      font-size: 1rem;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      border: 2px solid var(--accent);
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      border-color: var(--accent-hover);
      transform: translateY(-2px);
    }
    .btn-ghost {
      background: transparent;
      border: 2px solid rgba(255,255,255,0.8);
      color: white;
    }
    .btn-ghost:hover {
      background: rgba(255,255,255,0.15);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      transform: translateY(-2px);
    }
    .hero-image {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 350px;
      border-radius: var(--radius);
      position: relative;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    }
    .hero-geo {
      position: absolute;
      width: 160px;
      height: 160px;
      border: 2px solid rgba(255,255,255,0.18);
      border-radius: 50%;
      top: -20px;
      right: -20px;
      pointer-events: none;
    }
    /* 通用区块 */
    section {
      padding: var(--space-section) 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 3.5rem;
    }
    .section-title h2 {
      font-size: 2.25rem;
      font-weight: 700;
      color: var(--text-dark);
    }
    .section-title p {
      color: var(--text-muted);
      margin-top: 0.5rem;
      font-size: 1.1rem;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 28px;
    }
    .card {
      background: var(--card-white);
      border-radius: var(--radius);
      padding: 28px 24px;
      box-shadow: var(--shadow-card);
      transition: transform 0.25s, box-shadow 0.25s;
      border: none;
      display: flex;
      flex-direction: column;
    }
    .card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 52px;
      height: 52px;
      background: rgba(26,95,122,0.08);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 1.8rem;
      transition: 0.2s;
    }
    .card:hover .icon-circle {
      background: var(--primary);
      color: white;
    }
    .card h3 {
      font-size: 1.35rem;
      font-weight: 600;
      margin-bottom: 0.5rem;
    }
    .card p {
      color: var(--text-muted);
      font-size: 0.95rem;
      line-height: 1.6;
    }
    .pain-icon {
      color: var(--primary);
      font-size: 2.3rem;
      margin-bottom: 15px;
    }
    /* 解决方案步骤 */
    .steps {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      gap: 30px;
      position: relative;
    }
    .step {
      flex: 1;
      text-align: center;
      position: relative;
    }
    .step-number {
      font-size: 4rem;
      font-weight: 800;
      color: rgba(26,95,122,0.12);
      line-height: 1;
      margin-bottom: 0.5rem;
    }
    .step h3 {
      font-weight: 600;
      margin: 0.5rem 0;
    }
    .step p {
      color: var(--text-muted);
      font-size: 0.95rem;
    }
    .step-divider {
      position: absolute;
      top: 45px;
      right: -15px;
      width: 60px;
      border-top: 2px dashed rgba(26,95,122,0.35);
    }
    /* 成果数据 */
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--success);
    }
    .stat-label {
      color: var(--text-muted);
      font-size: 0.9rem;
      margin-top: 0.3rem;
    }
    /* 证言 */
    .testimonial-card {
      background: white;
      border-left: 5px solid var(--accent);
      padding: 24px;
      border-radius: 0 var(--radius) var(--radius) 0;
      box-shadow: var(--shadow-card);
    }
    .testimonial-text {
      font-style: italic;
      color: var(--text-dark);
      margin-bottom: 18px;
    }
    .avatar-row {
      display: flex;
      align-items: center;
      gap: 14px;
    }
    .avatar {
      width: 54px;
      height: 54px;
      border-radius: 50%;
      background: #ddd;
      background-image: url('/assets/images/coverpic/cover-2.webp');
      background-size: cover;
    }
    .avatar2 { background-image: url('/assets/images/coverpic/cover-3.webp'); }
    .avatar3 { background-image: url('/assets/images/coverpic/cover-4.webp'); }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: white;
      border-radius: var(--radius);
      margin-bottom: 16px;
      box-shadow: 0 2px 10px rgba(0,0,0,0.04);
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: white;
      transition: background 0.2s;
      font-size: 1.15rem;
    }
    .faq-question:hover {
      background: #f0f4f8;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F7F9FC;
      padding: 0 24px;
    }
    .faq-item.active .faq-answer {
      max-height: 180px;
      padding: 20px 24px;
    }
    /* CTA */
    .cta-band {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 70px 20px;
    }
    .cta-band h2 {
      font-size: 2.2rem;
      margin-bottom: 1rem;
    }
    .form-inline {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 14px;
      margin-top: 30px;
    }
    .form-inline input {
      padding: 13px 18px;
      border-radius: var(--radius-btn);
      border: 1px solid var(--border-light);
      background: white;
      font-size: 1rem;
      min-width: 220px;
    }
    .footer {
      background: #0F3D52;
      color: rgba(255,255,255,0.75);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer a {
      color: rgba(255,255,255,0.8);
      text-decoration: none;
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.2);
      padding-top: 20px;
      text-align: center;
      font-size: 0.9rem;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .hero-grid { grid-template-columns: 1fr; }
      .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .steps { flex-direction: column; }
      .step-divider { display: none; }
    }
    @media (max-width: 640px) {
      .grid-3, .grid-4, .footer-grid { grid-template-columns: 1fr; }
      .hero-content h1 { font-size: 2.2rem; }
    }