/* roulang page: index */
:root {
      --primary: #1A1A2E;
      --accent: #E94560;
      --bg: #F8F9FC;
      --card-bg: #FFFFFF;
      --text: #1E1E2F;
      --text-light: #6B7280;
      --amber: #F0A500;
      --success: #10B981;
      --muted: #94A3B8;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-card: 0 4px 20px rgba(26,26,46,0.06);
      --shadow-card-hover: 0 8px 30px rgba(233,69,96,0.12);
      --font-main: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", -apple-system, "Segoe UI", Roboto, sans-serif;
      --transition: 0.25s ease;
    }

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

    body {
      font-family: var(--font-main);
      background: var(--bg);
      color: var(--text);
      line-height: 1.8;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      padding-top: 72px;
      overflow-x: hidden;
    }

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

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

    button, .button {
      cursor: pointer;
      border: none;
      background: none;
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* Header / Navigation */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: #FFFFFF;
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      z-index: 100;
      display: flex;
      align-items: center;
    }

    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    .logo {
      display: flex;
      align-items: baseline;
      gap: 8px;
      font-weight: 700;
      font-size: 1.5rem;
      letter-spacing: -0.3px;
      color: var(--primary);
    }

    .logo .brand {
      color: var(--primary);
    }

    .logo .tagline {
      font-size: 0.8rem;
      font-weight: 400;
      color: var(--text-light);
      margin-left: 4px;
    }

    .desktop-nav {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .desktop-nav a {
      font-size: 1rem;
      font-weight: 500;
      color: var(--text);
      position: relative;
      padding: 0.25rem 0;
    }

    .desktop-nav a:hover,
    .desktop-nav a.active {
      color: var(--accent);
    }

    .btn-primary {
      background: var(--accent);
      color: #FFFFFF;
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      font-weight: 600;
      letter-spacing: 0.5px;
      display: inline-block;
      transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
      box-shadow: 0 4px 12px rgba(233,69,96,0.25);
      border: none;
    }

    .btn-primary:hover {
      background: #C81E3A;
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(233,69,96,0.35);
      color: #FFF;
    }

    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
      border-radius: var(--radius-btn);
      padding: 0.7rem 2rem;
      font-weight: 600;
      letter-spacing: 0.5px;
      display: inline-block;
      transition: all var(--transition);
    }

    .btn-outline:hover {
      background: var(--primary);
      color: #FFFFFF;
    }

    /* Mobile bottom tab */
    .mobile-bottom-tab {
      display: none;
    }

    /* Hamburger */
    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--primary);
      background: none;
      border: none;
    }

    @media (max-width: 1024px) {
      .desktop-nav {
        display: none;
      }

      .hamburger {
        display: block;
      }

      body {
        padding-top: 72px;
        padding-bottom: 70px;
      }

      .mobile-bottom-tab {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        height: 64px;
        background: #FFFFFF;
        border-top: 1px solid #E2E8F0;
        z-index: 99;
        justify-content: space-around;
        align-items: center;
      }

      .mobile-bottom-tab a {
        display: flex;
        flex-direction: column;
        align-items: center;
        font-size: 0.7rem;
        color: var(--text-light);
        gap: 4px;
        transition: color var(--transition);
      }

      .mobile-bottom-tab a i {
        font-size: 1.2rem;
      }

      .mobile-bottom-tab a.active {
        color: var(--accent);
      }
    }

    /* Section spacing */
    section {
      padding: 80px 0;
    }

    @media (max-width: 640px) {
      section {
        padding: 48px 0;
      }
    }

    h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--primary);
    }

    h2 {
      font-size: 36px;
      line-height: 1.3;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 1.5rem;
    }

    h3 {
      font-size: 22px;
      line-height: 1.4;
      font-weight: 600;
      color: var(--primary);
    }

    .text-light {
      color: var(--text-light);
    }

    /* Hero */
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }

    .hero-left {
      flex: 0 0 55%;
    }

    .hero-left h1 {
      margin-bottom: 1.2rem;
    }

    .hero-left .subtitle {
      font-size: 1.2rem;
      color: var(--text-light);
      margin-bottom: 2rem;
      line-height: 1.7;
    }

    .hero-right {
      flex: 0 0 40%;
    }

    .hero-right img {
      border-radius: 12px;
      box-shadow: 0 12px 30px rgba(0,0,0,0.08);
      width: 100%;
    }

    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-left, .hero-right {
        flex: auto;
        width: 100%;
      }
      h1 {
        font-size: 2.4rem;
      }
    }

    /* Highlights */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .highlight-card {
      background: var(--card-bg);
      padding: 2rem 1.5rem;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: transform var(--transition), box-shadow var(--transition);
      text-align: left;
    }

    .highlight-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }

    .icon-circle {
      width: 48px;
      height: 48px;
      background: #FEE2E5;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 1.2rem;
      color: var(--accent);
      font-size: 1.4rem;
      transition: background var(--transition), color var(--transition);
    }

    .highlight-card:hover .icon-circle {
      background: var(--accent);
      color: #FFF;
    }

    @media (max-width: 1024px) {
      .highlights-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 640px) {
      .highlights-grid {
        grid-template-columns: 1fr;
      }
    }

    /* Cases waterfall */
    .cases-waterfall {
      column-count: 3;
      column-gap: 24px;
    }

    .case-card {
      break-inside: avoid;
      margin-bottom: 24px;
      background: #FFF;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: transform var(--transition), box-shadow var(--transition);
      overflow: hidden;
    }

    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }

    .case-card img {
      width: 100%;
      object-fit: cover;
      border-radius: 12px 12px 0 0;
      transition: filter var(--transition);
    }

    .case-card:hover img {
      filter: saturate(1.1);
    }

    .case-body {
      padding: 1.2rem;
    }

    .case-tag {
      background: #FFF3E0;
      color: var(--amber);
      font-size: 0.8rem;
      padding: 0.2rem 0.8rem;
      border-radius: var(--radius-tag);
      display: inline-block;
      margin: 0.5rem 0;
    }

    @media (max-width: 1024px) {
      .cases-waterfall {
        column-count: 2;
      }
    }

    @media (max-width: 640px) {
      .cases-waterfall {
        column-count: 1;
      }
    }

    /* Compare */
    .compare-wrapper {
      display: flex;
      gap: 2rem;
    }

    .compare-col {
      flex: 1;
      padding: 2rem;
      border-radius: var(--radius-card);
    }

    .compare-left {
      background: #F1F5F9;
      color: #64748B;
    }

    .compare-right {
      background: #FFFFFF;
      border-left: 4px solid var(--accent);
      box-shadow: var(--shadow-card);
    }

    .compare-item {
      display: flex;
      align-items: center;
      gap: 0.8rem;
      margin-bottom: 1.2rem;
    }

    @media (max-width: 640px) {
      .compare-wrapper {
        flex-direction: column;
      }
    }

    /* FAQ */
    .accordion {
      background: #FFF;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      overflow: hidden;
    }

    .accordion-item {
      border-bottom: 1px solid #f0f0f0;
    }

    .accordion-title {
      background: #FFF;
      padding: 1.2rem 2rem;
      font-weight: 600;
      color: var(--text);
      transition: background var(--transition), color var(--transition);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .accordion-title:hover {
      background: #F8F9FC;
      color: var(--accent);
    }

    .accordion-content {
      background: #F8F9FC;
      padding: 0 2rem 1.2rem;
      color: var(--text-light);
      display: none;
    }

    .accordion-item.active .accordion-content {
      display: block;
    }

    /* CTA banner */
    .cta-banner {
      background: var(--primary);
      color: #FFF;
      text-align: center;
      padding: 4rem 0;
    }

    .cta-banner h2 {
      color: #FFF;
      margin-bottom: 0.8rem;
    }

    /* Footer */
    .site-footer {
      background: var(--primary);
      color: #CBD5E1;
      padding: 3rem 0 1.5rem;
    }

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

    .footer-grid a {
      color: #CBD5E1;
      display: block;
      margin-bottom: 0.5rem;
    }

    .footer-grid a:hover {
      color: var(--accent);
    }

    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 2rem;
      padding-top: 1.5rem;
      text-align: center;
      font-size: 0.9rem;
    }

    @media (max-width: 1024px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 640px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }