/* roulang page: index */
:root {
      --primary: #7B2FFF;
      --primary-dark: #6928D9;
      --primary-glow: rgba(123, 47, 255, 0.4);
      --accent: #FF6B2B;
      --accent-dark: #E55A1F;
      --cyan: #00E5FF;
      --bg-dark: #0F0F1A;
      --bg-darker: #0A0A14;
      --bg-light: #F8F7FC;
      --white: #FFFFFF;
      --text-main: #1A1A2E;
      --text-secondary: #5A5A72;
      --text-light: #B0B0C0;
      --border-light: #E8E4F0;
      --border-card: rgba(123, 47, 255, 0.06);
      --shadow-card: 0 4px 20px rgba(123, 47, 255, 0.08);
      --shadow-hover: 0 12px 32px rgba(123, 47, 255, 0.18);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 20px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      color: var(--text-main);
      background-color: var(--white);
      line-height: 1.7;
      font-size: 16px;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }
    /* 导航栏 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(15, 15, 26, 0.75);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      z-index: 1000;
      transition: background 0.3s;
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    #header.scrolled {
      background: rgba(10, 10, 20, 0.95);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .logo img {
      width: 38px;
      height: 38px;
      border-radius: 50%;
      object-fit: cover;
      border: 2px solid var(--primary);
    }
    .logo span {
      font-size: 22px;
      font-weight: 700;
      color: white;
      letter-spacing: 1px;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }
    .nav-menu a {
      color: rgba(255,255,255,0.8);
      font-weight: 500;
      font-size: 15px;
      padding: 6px 0;
      position: relative;
      transition: color var(--transition);
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--accent);
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: white;
      border-radius: 2px;
      transition: 0.3s;
    }
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: rgba(15, 15, 26, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        gap: 36px;
        transition: right 0.35s ease;
        box-shadow: -10px 0 30px rgba(0,0,0,0.5);
      }
      .nav-menu.open {
        right: 0;
      }
      .nav-menu a {
        font-size: 20px;
        color: white;
      }
      .hamburger {
        display: flex;
        z-index: 1100;
      }
    }
    /* Hero */
    #hero {
      min-height: 100vh;
      background: var(--bg-dark);
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding-top: 72px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 40px;
      width: 100%;
    }
    .hero-text {
      flex: 1;
      z-index: 2;
    }
    .hero-text h1 {
      font-size: clamp(36px, 5.5vw, 56px);
      font-weight: 700;
      line-height: 1.2;
      color: white;
      margin-bottom: 20px;
    }
    .hero-text .subtitle {
      font-size: 18px;
      color: rgba(255,255,255,0.7);
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all var(--transition);
      box-shadow: 0 4px 14px rgba(123, 47, 255, 0.35);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 0 22px var(--primary-glow);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all var(--transition);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .hero-visual {
      flex: 1;
      position: relative;
      z-index: 1;
    }
    .hero-visual img {
      border-radius: 20px;
      box-shadow: 0 20px 40px rgba(123, 47, 255, 0.25);
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-visual {
        width: 100%;
        margin-top: 30px;
      }
      .hero-buttons {
        justify-content: center;
      }
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      text-align: center;
      font-size: 38px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-main);
    }
    .section-sub {
      text-align: center;
      color: var(--text-secondary);
      max-width: 650px;
      margin: 0 auto 48px;
    }
    .underline {
      width: 60px;
      height: 4px;
      background: var(--primary);
      margin: 12px auto 36px;
      border-radius: 2px;
    }
    /* 卡片网格 */
    .grid-4, .grid-3 {
      display: grid;
      gap: 30px;
    }
    .grid-4 { grid-template-columns: repeat(4,1fr); }
    .grid-3 { grid-template-columns: repeat(3,1fr); }
    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2,1fr); }
      .grid-3 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 640px) {
      .grid-4, .grid-3 { grid-template-columns: 1fr; }
    }
    .card {
      background: white;
      border-radius: var(--radius-card);
      padding: 28px 24px;
      border: 1px solid var(--border-card);
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-6px);
    }
    /* 优势卡片 */
    .adv-icon {
      width: 64px;
      height: 64px;
      border-radius: 50%;
      background: rgba(123,47,255,0.1);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
    }
    .adv-icon img {
      width: 36px;
      height: 36px;
      object-fit: contain;
    }
    /* 产品卡片 */
    .product-img {
      height: 200px;
      object-fit: cover;
      border-radius: 12px 12px 0 0;
      width: 100%;
    }
    .product-features {
      list-style: none;
      margin: 16px 0;
      color: var(--text-secondary);
    }
    .product-features li::before {
      content: "•";
      color: var(--primary);
      margin-right: 8px;
    }
    /* 场景图文 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-img {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
    }
    .scenario-img img {
      width: 100%;
      height: auto;
      transition: transform 0.3s;
    }
    .scenario-img:hover img {
      transform: scale(1.02);
    }
    .scenario-text {
      flex: 1;
    }
    .tag {
      background: #F0E8FF;
      color: var(--primary);
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 500;
      display: inline-block;
      margin-right: 8px;
    }
    @media (max-width: 768px) {
      .scenario-row, .scenario-row.reverse {
        flex-direction: column;
      }
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      width: 100%;
      background: transparent;
      text-align: left;
      padding: 20px 10px;
      font-size: 18px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.3s;
      background: #FAF8FF;
      padding: 0 16px;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px;
    }
    /* CTA */
    .cta-block {
      background: var(--bg-dark);
      background-image: radial-gradient(circle at 30% 40%, rgba(123,47,255,0.2) 0%, transparent 60%);
      text-align: center;
      padding: 80px 20px;
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      padding: 16px 40px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      transition: all var(--transition);
    }
    .btn-accent:hover {
      background: var(--accent-dark);
      transform: scale(1.03);
    }
    /* Footer */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      padding: 60px 0 30px;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; }
    }
    .footer-brand p { color: var(--text-light); margin-top: 12px; }
    .footer-links a { display: block; color: var(--text-light); margin-bottom: 8px; }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      padding: 20px 0;
      color: var(--text-light);
    }