/* roulang page: index */
:root {
      --primary: #0B0E1A;
      --accent: #6C5CE7;
      --accent-hover: #5A4BD1;
      --silver: #A8B2D1;
      --gold: #FFD700;
      --bg-light: #F8F9FC;
      --card-bg: #FFFFFF;
      --text-main: #1A1A2E;
      --text-secondary: #5A5F7A;
      --border-light: #E9ECF4;
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --shadow-card: 0 8px 28px rgba(11,14,26,0.08);
      --shadow-hover: 0 18px 36px rgba(108,92,231,0.18);
      --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-body: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --max-width: 1280px;
      --header-height: 80px;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      border: none;
      outline: none;
      transition: var(--transition);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    h1, h2, h3 {
      font-family: var(--font-heading);
      font-weight: 700;
    }

    h1 {
      font-size: clamp(40px, 6vw, 56px);
      line-height: 1.2;
    }

    h2 {
      font-size: 32px;
      line-height: 1.3;
      font-weight: 600;
      margin-bottom: 16px;
      color: var(--primary);
    }

    h3 {
      font-size: 20px;
      line-height: 1.4;
      font-weight: 600;
      color: var(--text-main);
    }

    .section-title {
      display: flex;
      align-items: center;
      gap: 16px;
      margin-bottom: 32px;
    }

    .section-title::after {
      content: '';
      height: 3px;
      width: 48px;
      background: var(--accent);
      border-radius: 4px;
    }

    .section-sub {
      color: var(--text-secondary);
      font-size: 1.1rem;
    }

    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 0;
      transition: background 0.3s, box-shadow 0.3s, backdrop-filter 0.3s;
      background: transparent;
    }

    #nav.scrolled {
      background: rgba(11,14,26,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.2);
    }

    .nav-container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 1.5rem;
      color: white;
      letter-spacing: 1px;
    }

    .logo-icon {
      width: 36px;
      height: 36px;
      background: rgba(108,92,231,0.25);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      backdrop-filter: blur(4px);
      color: white;
      font-size: 1.2rem;
    }

    #nav.scrolled .logo {
      color: white;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 1rem;
    }

    .nav-links a:hover {
      color: var(--gold);
    }

    .btn-primary {
      background: var(--accent);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(108,92,231,0.4);
    }

    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 22px rgba(108,92,231,0.6);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent);
      color: var(--accent);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
    }

    .btn-outline:hover {
      background: rgba(108,92,231,0.08);
      transform: translateY(-2px);
    }

    .btn-gold {
      border-color: var(--gold);
      color: var(--gold);
    }

    .mobile-nav {
      display: none;
    }

    /* Hero */
    #hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, #1a1f3a, #0B0E1A);
      position: relative;
      overflow: hidden;
    }

    .hero-particles {
      position: absolute;
      inset: 0;
      pointer-events: none;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
      color: white;
    }

    .hero-content h1 {
      color: white;
      margin-bottom: 20px;
    }

    .hero-highlight {
      color: var(--gold);
    }

    .hero-sub {
      font-size: 1.25rem;
      color: var(--silver);
      margin-bottom: 32px;
    }

    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }

    .hero-visual {
      position: absolute;
      right: 0;
      top: 0;
      width: 50%;
      height: 100%;
      background: radial-gradient(circle at 20% 50%, rgba(108,92,231,0.25), transparent 70%);
    }

    /* Trust */
    #trust {
      padding: 60px 0;
      background: white;
      border-bottom: 1px solid var(--border-light);
    }

    .trust-grid {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      gap: 24px;
      text-align: center;
    }

    .trust-item i {
      font-size: 2rem;
      color: var(--accent);
      margin-bottom: 8px;
    }

    .trust-number {
      font-size: 2rem;
      font-weight: 700;
      color: var(--primary);
    }

    /* Features 异形卡片 */
    #features {
      padding: 100px 0;
    }

    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      align-items: start;
    }

    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      border: 1px solid var(--border-light);
    }

    .feature-card:nth-child(2) {
      margin-top: -24px;
      margin-bottom: 24px;
    }

    .feature-card:hover {
      transform: scale(1.02);
      box-shadow: var(--shadow-hover);
    }

    .feature-icon {
      width: 56px;
      height: 56px;
      background: rgba(108,92,231,0.1);
      border-radius: 20px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
      font-size: 1.8rem;
      margin-bottom: 20px;
    }

    /* Services 左右交替 */
    #services {
      padding: 80px 0;
    }

    .service-row {
      display: flex;
      align-items: center;
      gap: 64px;
      margin-bottom: 80px;
    }

    .service-row.reverse {
      flex-direction: row-reverse;
    }

    .service-img {
      flex: 1;
      border-radius: 20px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }

    .service-img img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }

    .service-text {
      flex: 1;
    }

    .service-list {
      list-style: none;
      margin-top: 20px;
    }

    .service-list li {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 10px;
    }

    .service-list li::before {
      content: "●";
      color: var(--accent);
      font-size: 1.2rem;
    }

    /* Scenarios */
    #scenarios {
      padding: 80px 0;
      background: var(--bg-light);
    }

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

    .scenario-card {
      height: 320px;
      border-radius: 20px;
      background-size: cover;
      background-position: center;
      position: relative;
      overflow: hidden;
      display: flex;
      align-items: flex-end;
      color: white;
      padding: 24px;
      transition: var(--transition);
    }

    .scenario-card::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(to top, rgba(11,14,26,0.8), transparent);
    }

    .scenario-card:hover {
      transform: translateY(-8px);
    }

    .scenario-content {
      position: relative;
      z-index: 2;
    }

    /* Cases */
    #cases {
      padding: 80px 0;
    }

    .cases-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }

    .big-stat {
      font-size: 3.5rem;
      font-weight: 700;
      color: var(--accent);
    }

    .case-cards {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
    }

    .case-item {
      background: white;
      border-radius: 14px;
      padding: 20px;
      border-left: 5px solid var(--accent);
      box-shadow: var(--shadow-card);
    }

    /* FAQ */
    #faq {
      padding: 80px 0;
    }

    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }

    .faq-item {
      background: white;
      border-radius: 12px;
      padding: 18px 24px;
      cursor: pointer;
      border: 1px solid var(--border-light);
      transition: var(--transition);
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
    }

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

    .faq-item.active {
      border-left: 4px solid var(--accent);
      background: #f5f3ff;
    }

    /* CTA */
    #cta {
      background: var(--primary);
      padding: 100px 0;
      text-align: center;
      color: white;
    }

    #cta h2 {
      color: white;
      font-size: 2.8rem;
    }

    /* Footer */
    #footer {
      background: #0B0E1A;
      color: var(--silver);
      padding: 60px 0 20px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .features-grid, .scenario-grid { grid-template-columns: 1fr; }
      .service-row { flex-direction: column; }
      .cases-wrapper { grid-template-columns: 1fr; }
      .faq-grid { grid-template-columns: 1fr; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-nav {
        display: flex;
        position: fixed;
        bottom: 16px;
        left: 16px;
        right: 16px;
        background: white;
        border-radius: 28px;
        padding: 8px 16px;
        justify-content: space-around;
        box-shadow: 0 8px 24px rgba(0,0,0,0.12);
        z-index: 1000;
      }
      .trust-grid { grid-template-columns: repeat(2,1fr); }
    }