/* roulang page: index */
:root {
      --deep-space: #1E1B4B;
      --starlight-gold: #F5A623;
      --competition-orange: #FF6B35;
      --warm-white: #FAF9F7;
      --pure-white: #FFFFFF;
      --ink-gray: #1F2937;
      --stone-gray: #4B5563;
      --border-light: #E5E7EB;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 6px 24px rgba(30,27,75,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --transition: 0.3s ease;
      --font-zh: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", -apple-system, sans-serif;
      --font-en: "Inter", "SF Pro Display", system-ui;
    }

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

    html {
      scroll-behavior: smooth;
      scroll-padding-top: 80px;
    }

    body {
      font-family: var(--font-zh);
      background-color: var(--warm-white);
      color: var(--stone-gray);
      line-height: 1.7;
      font-size: 15px;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-light);
      display: flex;
      align-items: center;
      z-index: 1000;
      transition: box-shadow var(--transition);
    }
    #header.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-weight: 700;
      font-size: 20px;
      letter-spacing: -0.5px;
      color: var(--deep-space);
      display: flex;
      align-items: baseline;
      gap: 4px;
    }
    .logo .en {
      font-family: var(--font-en);
      font-size: 14px;
      font-weight: 500;
      color: var(--starlight-gold);
      margin-left: 4px;
      letter-spacing: 0.5px;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-menu a {
      font-size: 15px;
      color: var(--stone-gray);
      padding: 4px 0;
      border-bottom: 2px solid transparent;
      transition: 0.2s;
      font-weight: 500;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--deep-space);
      border-bottom-color: var(--starlight-gold);
    }
    .nav-cta {
      background: var(--starlight-gold);
      color: white !important;
      padding: 8px 20px !important;
      border-radius: 20px;
      font-size: 14px;
      font-weight: 600;
      transition: background 0.25s, transform 0.2s;
      display: inline-block;
    }
    .nav-cta:hover {
      background: var(--competition-orange);
      transform: translateY(-1px);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--starlight-gold);
      border-radius: 2px;
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      right: 0;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: var(--deep-space);
      padding: 80px 32px;
      flex-direction: column;
      gap: 28px;
      z-index: 999;
      transform: translateX(100%);
      transition: transform 0.4s ease;
    }
    .mobile-menu.open {
      transform: translateX(0);
    }
    .mobile-menu a {
      color: white;
      font-size: 18px;
      font-weight: 500;
      border-bottom: 1px solid rgba(255,255,255,0.15);
      padding-bottom: 8px;
    }
    .mobile-menu .nav-cta {
      background: var(--starlight-gold);
      text-align: center;
      margin-top: 20px;
      padding: 14px;
      border-radius: 30px;
    }

    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-header {
      text-align: center;
      margin-bottom: 48px;
    }
    h2 {
      font-size: 36px;
      font-weight: 600;
      color: var(--deep-space);
      line-height: 1.3;
      margin-bottom: 16px;
      letter-spacing: -0.3px;
    }
    .subtitle {
      font-size: 17px;
      color: var(--stone-gray);
    }

    /* Hero */
    #hero {
      padding: 120px 0 80px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left {
      flex: 1 1 55%;
    }
    .hero-right {
      flex: 1 1 45%;
    }
    .hero-badge {
      display: inline-block;
      background: rgba(255,107,53,0.1);
      color: var(--competition-orange);
      padding: 6px 16px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 500;
      margin-bottom: 20px;
    }
    h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--deep-space);
      margin-bottom: 20px;
    }
    h1 .highlight {
      color: var(--starlight-gold);
    }
    .hero-desc {
      font-size: 17px;
      color: var(--stone-gray);
      margin-bottom: 32px;
      max-width: 520px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 20px;
    }
    .btn-primary {
      background: var(--starlight-gold);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: 0.25s;
      display: inline-block;
      border: none;
      cursor: pointer;
      font-size: 16px;
    }
    .btn-primary:hover {
      background: var(--competition-orange);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(245,166,35,0.3);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--deep-space);
      color: var(--deep-space);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: 0.25s;
    }
    .btn-secondary:hover {
      background: var(--deep-space);
      color: white;
    }
    .rating-text {
      font-size: 13px;
      color: var(--stone-gray);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .hero-image {
      width: 100%;
      border-radius: 16px;
      box-shadow: var(--shadow-hover);
    }

    /* 优势网格 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .adv-card {
      background: var(--pure-white);
      padding: 28px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      text-align: left;
    }
    .adv-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .adv-icon {
      width: 48px;
      height: 48px;
      background: rgba(30,27,75,0.08);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 18px;
      color: var(--starlight-gold);
      font-size: 22px;
    }
    .adv-card h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--ink-gray);
      margin-bottom: 10px;
    }

    /* 产品瀑布流 */
    .masonry {
      columns: 3;
      column-gap: 24px;
    }
    .product-card {
      background: var(--pure-white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      margin-bottom: 24px;
      break-inside: avoid;
      transition: var(--transition);
    }
    .product-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .product-card img {
      width: 100%;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .product-card:hover img {
      transform: scale(1.03);
    }
    .product-body {
      padding: 20px;
    }
    .product-body h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--ink-gray);
    }
    .text-link {
      color: var(--starlight-gold);
      font-weight: 600;
      display: inline-block;
      margin-top: 10px;
      border-bottom: 2px solid transparent;
    }
    .text-link:hover {
      border-bottom-color: var(--starlight-gold);
    }

    /* 案例看板 */
    .cases-layout {
      display: flex;
      gap: 40px;
      align-items: center;
    }
    .metrics-col {
      flex: 1 1 35%;
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .metric-card {
      background: var(--pure-white);
      padding: 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
    }
    .metric-number {
      font-size: 40px;
      font-weight: 700;
      color: var(--starlight-gold);
      font-family: var(--font-en);
    }
    .case-card {
      flex: 1 1 60%;
      position: relative;
      border-radius: var(--radius-card);
      overflow: hidden;
    }
    .case-card img {
      width: 100%;
      border-radius: var(--radius-card);
    }
    .case-overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      background: linear-gradient(transparent, rgba(30,27,75,0.85));
      padding: 32px 24px;
      color: white;
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }
    .faq-item {
      background: var(--pure-white);
      border-radius: var(--radius-card);
      padding: 0;
      border: 1px solid var(--border-light);
      overflow: hidden;
    }
    .faq-question {
      padding: 16px;
      font-weight: 600;
      color: var(--ink-gray);
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #FAF9F7;
      padding: 0 16px;
    }
    .faq-item.open .faq-answer {
      max-height: 150px;
      padding: 16px;
    }

    /* CTA */
    .cta-band {
      background: linear-gradient(135deg, #1E1B4B 0%, #312E81 100%);
      text-align: center;
      padding: 80px 24px;
      color: white;
      border-radius: 12px;
      margin: 0 24px;
    }
    .cta-band h2 {
      color: white;
    }

    /* 页脚 */
    footer {
      background: var(--deep-space);
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .back-to-top {
      position: fixed;
      bottom: 30px;
      right: 30px;
      width: 48px;
      height: 48px;
      background: var(--starlight-gold);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 20px;
      box-shadow: 0 4px 14px rgba(0,0,0,0.2);
      transition: 0.3s;
      opacity: 0;
      visibility: hidden;
    }
    .back-to-top.show {
      opacity: 1;
      visibility: visible;
    }

    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; }
      .advantages-grid { grid-template-columns: repeat(2,1fr); }
      .masonry { columns: 2; }
      .cases-layout { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .advantages-grid, .masonry, .faq-grid, .footer-grid { grid-template-columns: 1fr; }
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
    }