/* roulang page: index */
:root {
      --primary: #0B2B26;
      --accent: #E85D04;
      --bg-warm: #F7F4EF;
      --dark-bg: #1A1A1A;
      --text-main: #1E1E1E;
      --text-muted: #5A5A5A;
      --success: #2D6A4F;
      --border-light: #E0DBD2;
      --card-border: #E8E3DA;
      --white: #FFFFFF;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 28px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
      --font-number: 'Inter', 'SF Pro Display', system-ui;
      --max-width: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--bg-warm);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 15px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      border: none;
      outline: none;
    }
    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      height: 72px;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      transition: background 0.25s ease, box-shadow 0.25s ease;
      border-bottom: 1px solid transparent;
    }
    .site-header.scrolled {
      background: rgba(255,255,255,0.95);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-light);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
    }
    .logo svg {
      width: 24px;
      height: 24px;
      fill: var(--accent);
    }
    .desktop-nav {
      display: flex;
      align-items: center;
      gap: 36px;
    }
    .desktop-nav a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-main);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
    }
    .desktop-nav a:hover,
    .desktop-nav a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      font-size: 15px;
      transition: background 0.25s ease, transform 0.2s, box-shadow 0.2s;
      display: inline-block;
    }
    .btn-primary:hover {
      background: #C94D00;
      transform: translateY(-2px);
      box-shadow: 0 6px 18px rgba(232, 93, 4, 0.3);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      font-size: 15px;
      transition: all 0.25s ease;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .mobile-nav {
      display: none;
    }
    @media (max-width: 767px) {
      .desktop-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
        position: fixed;
        bottom: 20px;
        left: 50%;
        transform: translateX(-50%);
        background: white;
        box-shadow: 0 4px 24px rgba(0,0,0,0.12);
        border-radius: 40px;
        padding: 8px 20px;
        gap: 18px;
        z-index: 1001;
        backdrop-filter: blur(20px);
      }
      .mobile-nav a {
        display: flex;
        flex-direction: column;
        align-items: center;
        font-size: 12px;
        color: var(--text-muted);
        gap: 4px;
        padding: 6px 8px;
        border-radius: 30px;
        transition: 0.2s;
        font-weight: 500;
      }
      .mobile-nav a span {
        font-size: 18px;
        line-height: 1;
      }
      .mobile-nav a.active {
        color: var(--primary);
        background: rgba(11, 43, 38, 0.06);
      }
    }
    /* 区块间距 */
    section {
      padding: 100px 0;
      scroll-margin-top: 72px;
    }
    @media (max-width: 767px) {
      section {
        padding: 64px 0;
      }
    }
    h2 {
      font-family: var(--font-title);
      font-size: 32px;
      font-weight: 600;
      margin-bottom: 16px;
      letter-spacing: 0.5px;
    }
    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      gap: 48px;
      min-height: 90vh;
      padding-top: 100px;
      background: radial-gradient(circle at 80% 20%, rgba(11,43,38,0.04) 0%, transparent 55%);
      position: relative;
    }
    .hero-left {
      flex: 0 0 55%;
    }
    .hero-right {
      flex: 0 0 45%;
    }
    .hero h1 {
      font-family: var(--font-title);
      font-size: 44px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--primary);
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 36px;
      max-width: 480px;
    }
    .hero-actions {
      display: flex;
      gap: 20px;
    }
    @media (max-width: 1023px) {
      .hero {
        flex-direction: column;
        text-align: center;
      }
      .hero-left, .hero-right {
        flex: auto;
      }
      .hero-actions {
        justify-content: center;
      }
      .hero-sub {
        margin-left: auto;
        margin-right: auto;
      }
    }
    /* 数据带 */
    .stats-band {
      display: flex;
      justify-content: space-around;
      text-align: center;
      padding: 40px 0;
      border-top: 1px solid var(--border-light);
      border-bottom: 1px solid var(--border-light);
      margin: 0 24px;
    }
    .stat-item {
      flex: 1;
      position: relative;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 800;
      color: var(--primary);
    }
    .stat-label {
      font-size: 13px;
      color: var(--text-muted);
      margin-top: 8px;
    }
    @media (max-width: 767px) {
      .stats-band {
        flex-wrap: wrap;
        gap: 24px;
        justify-content: center;
      }
      .stat-item {
        flex: 0 0 40%;
      }
    }
    /* 亮点网格 */
    .grid-2x3 {
      display: grid;
      grid-template-columns: 1fr 1fr 1fr;
      gap: 24px;
    }
    .highlight-card {
      background: white;
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      padding: 28px;
      transition: var(--transition);
      box-shadow: var(--shadow-sm);
    }
    .highlight-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary);
    }
    .wide-card {
      grid-column: span 2;
      border-left: 4px solid var(--accent);
    }
    .highlight-icon {
      font-size: 36px;
      margin-bottom: 20px;
      transition: transform 0.3s;
    }
    .highlight-card:hover .highlight-icon {
      transform: rotate(8deg);
    }
    h3 {
      font-family: var(--font-title);
      font-weight: 600;
      font-size: 20px;
      margin-bottom: 8px;
    }
    @media (max-width: 1023px) {
      .grid-2x3 {
        grid-template-columns: 1fr 1fr;
      }
      .wide-card {
        grid-column: span 1;
      }
    }
    @media (max-width: 767px) {
      .grid-2x3 {
        grid-template-columns: 1fr;
      }
    }
    /* 流程 */
    .steps-line {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      position: relative;
      margin-top: 40px;
    }
    .step {
      text-align: center;
      flex: 1;
      position: relative;
    }
    .step-circle {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: white;
      border: 2px solid var(--primary);
      color: var(--primary);
      margin: 0 auto 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 20px;
      transition: 0.3s;
      position: relative;
      z-index: 2;
    }
    .step.active .step-circle {
      background: var(--primary);
      color: white;
      box-shadow: 0 0 0 8px rgba(11,43,38,0.15);
    }
    .step::after {
      content: '';
      position: absolute;
      top: 24px;
      left: 58%;
      width: 84%;
      height: 2px;
      background: repeating-linear-gradient(to right, #D1CCC2 0px, #D1CCC2 6px, transparent 6px, transparent 12px);
      z-index: 1;
    }
    .step:last-child::after {
      display: none;
    }
    @media (max-width: 767px) {
      .steps-line {
        flex-direction: column;
        gap: 32px;
      }
      .step::after {
        display: none;
      }
    }
    /* 案例瀑布 */
    .case-waterfall {
      columns: 3;
      column-gap: 32px;
      margin-top: 40px;
    }
    .case-card {
      break-inside: avoid;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      margin-bottom: 32px;
      border: 1px solid var(--card-border);
      transition: var(--transition);
      box-shadow: var(--shadow-sm);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 220px;
      background-size: cover;
      background-position: center;
    }
    .case-content {
      padding: 24px;
    }
    .tags {
      display: flex;
      gap: 8px;
      margin-top: 12px;
    }
    .tag {
      background: #E9F0EC;
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 4px;
      font-size: 13px;
    }
    @media (max-width: 1023px) {
      .case-waterfall {
        columns: 2;
      }
    }
    @media (max-width: 767px) {
      .case-waterfall {
        columns: 1;
      }
    }
    /* 对比表 */
    .compare-table {
      display: flex;
      gap: 24px;
      margin-top: 32px;
    }
    .compare-col {
      flex: 1;
      border-radius: var(--radius-card);
      padding: 28px;
      background: #F0EDE6;
    }
    .compare-col.highlight {
      background: #E9F0EC;
      border: 1px solid var(--primary);
    }
    .compare-header {
      font-weight: 700;
      font-size: 22px;
      margin-bottom: 24px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .compare-row {
      display: flex;
      justify-content: space-between;
      padding: 14px 0;
      border-bottom: 1px solid var(--border-light);
    }
    @media (max-width: 767px) {
      .compare-table {
        flex-direction: column;
      }
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      transition: background 0.2s;
    }
    .faq-question {
      padding: 20px 0;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-muted);
      padding-bottom: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 120px;
      padding-bottom: 20px;
    }
    .faq-item.open .arrow {
      transform: rotate(180deg);
    }
    /* CTA横幅 */
    .cta-banner {
      background: var(--dark-bg);
      color: white;
      border-radius: 20px;
      padding: 48px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-top: 40px;
    }
    @media (max-width: 767px) {
      .cta-banner {
        flex-direction: column;
        gap: 24px;
        text-align: center;
      }
    }
    footer {
      background: var(--dark-bg);
      color: #B0B0B0;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    @media (max-width: 767px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    .social-icons span {
      margin-right: 14px;
      font-size: 20px;
    }