/* roulang page: index */
:root {
      --primary: #E94057;
      --primary-hover: #FF5A75;
      --secondary-bg: #0A0E27;
      --accent: #00F0FF;
      --accent-hover: #00d9e6;
      --text-primary: #FFFFFF;
      --text-secondary: #B0B8D0;
      --card-bg: #141A35;
      --border-light: rgba(255, 255, 255, 0.08);
      --border-accent: rgba(0, 240, 255, 0.15);
      --shadow-glow: 0 12px 28px rgba(0, 240, 255, 0.15);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-title: 'DIN Alternate', 'Roboto Mono', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
      --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
    }

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

    body {
      background-color: var(--secondary-bg);
      color: var(--text-primary);
      font-family: var(--font-body);
      line-height: 1.7;
      font-size: 16px;
      overflow-x: hidden;
    }

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

    /* 导航栏 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 14, 39, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.3);
      transition: all 0.3s ease;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .logo {
      font-family: var(--font-title);
      font-weight: 800;
      font-size: 28px;
      letter-spacing: -0.5px;
      background: linear-gradient(135deg, #E94057 0%, #FF8A9A 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      display: flex;
      align-items: center;
      text-decoration: none;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-link {
      color: var(--text-secondary);
      text-decoration: none;
      font-weight: 500;
      transition: color 0.2s;
      font-size: 1rem;
    }
    .nav-link:hover {
      color: var(--accent);
    }
    .nav-cta {
      background: var(--primary);
      color: white;
      padding: 10px 20px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      text-decoration: none;
      transition: background 0.2s, transform 0.2s;
    }
    .nav-cta:hover {
      background: var(--primary-hover);
      transform: scale(1.04);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 5px;
    }
    .hamburger span {
      width: 25px;
      height: 3px;
      background: var(--text-primary);
      border-radius: 3px;
      transition: all 0.3s;
      display: block;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 70px;
      left: 0;
      width: 100%;
      background: var(--secondary-bg);
      flex-direction: column;
      padding: 24px;
      gap: 24px;
      border-top: 1px solid var(--border-light);
      z-index: 999;
    }
    .mobile-menu.active {
      display: flex;
    }
    .mobile-menu .nav-link, .mobile-menu .nav-cta {
      font-size: 1.2rem;
      width: fit-content;
    }

    /* Hero */
    #hero {
      padding: 140px 0 100px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-repeat: no-repeat;
      position: relative;
    }
    #hero::before {
      content: '';
      position: absolute;
      top: 0; left: 0; right: 0; bottom: 0;
      background: rgba(10, 14, 39, 0.75);
      z-index: 1;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 40px;
    }
    .hero-left {
      flex: 1 1 500px;
    }
    .hero-right {
      flex: 1 1 400px;
      display: flex;
      justify-content: center;
    }
    h1 {
      font-family: var(--font-title);
      font-weight: 800;
      font-size: 56px;
      line-height: 1.1;
      letter-spacing: -0.02em;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 28px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      font-weight: 700;
      border: none;
      cursor: pointer;
      transition: all 0.2s;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: scale(1.04);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent);
      color: var(--accent);
      padding: 14px 28px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      font-weight: 700;
      transition: all 0.2s;
    }
    .btn-outline:hover {
      background: var(--accent);
      color: var(--secondary-bg);
    }

    /* 通用section */
    section {
      padding: 100px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }
    h2 {
      font-family: var(--font-title);
      font-weight: 800;
      font-size: 40px;
      letter-spacing: -0.02em;
      line-height: 1.2;
      color: white;
    }
    .section-title p {
      color: var(--text-secondary);
      margin-top: 12px;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--card-bg);
      border: 1px solid var(--border-accent);
      border-radius: var(--radius-card);
      padding: 28px;
      transition: all 0.3s;
      position: relative;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-glow);
      border-color: var(--accent);
    }
    .card-left-line {
      border-left: 4px solid var(--accent);
      padding-left: 24px;
    }
    .card h3 {
      font-weight: 800;
      font-size: 24px;
      margin-bottom: 12px;
    }
    .data-highlight {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 28px;
      color: var(--accent);
      margin: 12px 0;
    }
    .cover-img {
      width: 100%;
      height: 180px;
      object-fit: cover;
      border-radius: 8px;
      margin-top: 16px;
      opacity: 0.85;
    }
    .results-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
    }
    .stat-item {
      text-align: center;
      padding: 24px;
    }
    .stat-num {
      font-family: var(--font-title);
      font-size: 44px;
      color: var(--accent);
      font-weight: 700;
    }
    .testimonial-carousel {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 20px;
    }
    .testimonial-card {
      min-width: 320px;
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 24px;
    }

    .faq-item {
      background: var(--card-bg);
      margin-bottom: 16px;
      border-radius: 8px;
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      border-left: 3px solid transparent;
      transition: all 0.2s;
    }
    .faq-question.active {
      color: var(--accent);
      border-left-color: var(--primary);
    }
    .faq-answer {
      padding: 0 24px 18px;
      color: var(--text-secondary);
      display: none;
    }
    .faq-answer.open {
      display: block;
    }
    .arrow {
      transition: transform 0.3s;
    }
    .arrow.rotate {
      transform: rotate(180deg);
    }
    #cta {
      background: linear-gradient(135deg, #0A0E27 0%, #141A35 100%);
      border-top: 1px solid var(--border-accent);
      border-bottom: 1px solid var(--border-accent);
      text-align: center;
    }
    #footer {
      padding: 80px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-logo {
      font-size: 28px;
      font-weight: 800;
      background: linear-gradient(135deg, #E94057, #FF8A9A);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .footer-links a {
      display: block;
      color: var(--text-secondary);
      text-decoration: none;
      margin-bottom: 12px;
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.08);
      padding-top: 24px;
      text-align: center;
      color: var(--text-secondary);
    }

    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
      .results-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      h1 { font-size: 38px; }
      h2 { font-size: 30px; }
      .grid-3, .results-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .hero-right { display: none; }
    }
    @media (max-width: 520px) {
      .footer-grid { grid-template-columns: 1fr; }
    }