/* roulang page: index */
:root {
      --primary-deep: #0B0E1A;
      --accent-purple: #6C3CE0;
      --accent-cyan: #00E5E5;
      --bg-light: #FAFAFC;
      --card-bg: #FFFFFF;
      --text-dark: #1E1E2A;
      --text-mid: #4A4A5E;
      --text-light: #9CA3AF;
      --border-light: rgba(0, 0, 0, 0.05);
      --shadow-card: 0 4px 16px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 12px 28px rgba(108, 60, 224, 0.12);
      --radius-card: 16px;
      --radius-btn: 10px;
      --radius-img: 14px;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Inter', system-ui, sans-serif;
      --transition: all 0.2s ease;
      --container-max: 1200px;
      --gap-section: 100px;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.8;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 32px;
      width: 100%;
    }

    img {
      max-width: 100%;
      height: auto;
      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: 500;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    h1, h2, h3, h4 {
      font-family: var(--font-heading);
      font-weight: 600;
      line-height: 1.3;
      color: var(--text-dark);
    }

    h1 {
      font-size: 48px;
      letter-spacing: -0.5px;
    }

    h2 {
      font-size: 36px;
      margin-bottom: 16px;
    }

    h3 {
      font-size: 22px;
      margin-bottom: 12px;
    }

    p {
      color: var(--text-mid);
      font-size: 16px;
      line-height: 1.8;
      margin-bottom: 16px;
    }

    .section-title {
      text-align: center;
      margin-bottom: 20px;
    }
    .section-subtitle {
      text-align: center;
      color: var(--text-light);
      font-size: 18px;
      margin-bottom: 56px;
      max-width: 600px;
      margin-left: auto;
      margin-right: auto;
    }

    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background 0.3s, box-shadow 0.3s;
      height: 76px;
      display: flex;
      align-items: center;
    }
    .site-header.scrolled {
      background: #FFFFFF;
      box-shadow: 0 2px 20px rgba(0,0,0,0.05);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      background: rgba(255,255,255,0.92);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-family: var(--font-heading);
      font-size: 24px;
      font-weight: 700;
      color: #fff;
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: color 0.3s;
    }
    .scrolled .logo {
      color: var(--primary-deep);
    }
    .logo span {
      color: var(--accent-cyan);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 36px;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 15px;
      color: rgba(255,255,255,0.85);
      position: relative;
      padding: 6px 0;
      transition: color 0.2s;
    }
    .scrolled .nav-links a {
      color: var(--text-dark);
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-cyan);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.2s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .btn-header {
      background: var(--accent-purple);
      color: white;
      padding: 9px 22px;
      border-radius: 30px;
      font-size: 14px;
      font-weight: 600;
      letter-spacing: 0.3px;
      box-shadow: 0 4px 10px rgba(108,60,224,0.4);
    }
    .btn-header:hover {
      background: #5A2EC4;
      box-shadow: 0 6px 18px rgba(108,60,224,0.5);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 26px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }
    .scrolled .hamburger span {
      background: var(--primary-deep);
    }

    @media (max-width: 1023px) {
      .nav-links {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: rgba(11,14,26,0.96);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 40px;
        z-index: 999;
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links a {
        font-size: 24px;
        color: white;
      }
      .hamburger {
        display: flex;
        z-index: 1001;
      }
      .btn-header {
        display: none;
      }
    }

    /* Hero */
    #hero {
      background: var(--primary-deep);
      color: white;
      min-height: 620px;
      display: flex;
      align-items: center;
      padding: 130px 0 80px;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 5fr 7fr;
      gap: 60px;
      align-items: center;
    }
    .hero-text h1 {
      color: white;
      margin-bottom: 20px;
    }
    .hero-text .subtitle {
      color: rgba(255,255,255,0.7);
      font-size: 18px;
      margin-bottom: 36px;
    }
    .hero-buttons {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-purple);
      color: white;
      padding: 13px 34px;
      border-radius: 30px;
      font-weight: 600;
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 13px 34px;
      border-radius: 30px;
    }
    .btn-primary:hover { background: #5A2EC4; }
    .btn-secondary:hover { background: rgba(0,229,229,0.08); }
    .hero-image img {
      border-radius: 28px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.4);
    }

    @media (max-width: 1023px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-image { order: -1; max-width: 380px; margin: 0 auto; }
      .hero-buttons { justify-content: center; }
    }

    /* features 不规则 */
    #features {
      padding: var(--gap-section) 0;
    }
    .features-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 24px;
      margin-bottom: 24px;
    }
    .features-row-second {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 30px 28px;
      box-shadow: var(--shadow-card);
      border-left: 5px solid var(--accent-cyan);
      transition: var(--transition);
    }
    .feature-card:hover {
      box-shadow: var(--shadow-hover);
      border-left-color: var(--accent-purple);
    }
    .feature-icon {
      font-size: 32px;
      color: var(--accent-cyan);
      margin-bottom: 18px;
    }
    .feature-large {
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    @media (max-width: 768px) {
      .features-grid, .features-row-second {
        grid-template-columns: 1fr;
      }
    }

    /* scenes 场景 */
    #scenes {
      padding: var(--gap-section) 0;
      background: #fff;
    }
    .scene-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      margin-bottom: 90px;
    }
    .scene-row.reverse { direction: rtl; }
    .scene-row.reverse .scene-text { direction: ltr; }
    .scene-text h2 { margin-top: 0; }
    .scene-img img {
      border-radius: 20px;
    }
    @media (max-width: 768px) {
      .scene-row, .scene-row.reverse {
        grid-template-columns: 1fr;
        direction: ltr;
        gap: 30px;
      }
    }

    /* cases */
    #cases {
      padding: var(--gap-section) 0;
    }
    .cases-scroll {
      display: flex;
      gap: 28px;
      overflow-x: auto;
      padding-bottom: 20px;
    }
    .case-card {
      min-width: 260px;
      background: white;
      border-radius: 20px;
      padding: 28px;
      box-shadow: var(--shadow-card);
      text-align: center;
    }
    .case-number {
      font-size: 44px;
      font-weight: 700;
      color: var(--accent-cyan);
    }
    @media (max-width: 768px) {
      .cases-scroll { flex-direction: column; }
    }

    /* pricing */
    #pricing {
      padding: var(--gap-section) 0;
      background: #fff;
    }
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .price-card {
      background: white;
      border-radius: 24px;
      padding: 38px 28px;
      box-shadow: 0 8px 24px rgba(0,0,0,0.04);
      text-align: center;
      border: 1px solid transparent;
      transition: 0.2s;
    }
    .price-card.recommended {
      border: 2px solid var(--accent-purple);
      transform: scale(1.02);
    }
    .price-amount {
      font-size: 42px;
      font-weight: 700;
      color: var(--primary-deep);
    }
    .btn-outline {
      border: 1px solid var(--accent-cyan);
      color: var(--accent-cyan);
      background: transparent;
      padding: 12px 29px;
      border-radius: 30px;
    }
    @media (max-width: 768px) {
      .pricing-grid { grid-template-columns: 1fr; }
    }

    /* faq */
    #faq {
      padding: var(--gap-section) 0;
    }
    .faq-item {
      border-bottom: 1px solid #e5e7eb;
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: 0.3s;
      color: var(--text-mid);
    }
    .faq-item.open .faq-answer { max-height: 200px; margin-top: 14px; }

    .cta-block {
      background: var(--primary-deep);
      padding: 100px 0;
      text-align: center;
    }
    .footer {
      background: #141828;
      color: #bbb;
      padding: 50px 0 28px;
    }