/* roulang page: index */
:root {
      --charcoal: #1E1E1E;
      --warm-lime: #F5F2ED;
      --burgundy: #8B2E3A;
      --burgundy-dark: #6F1F2A;
      --fir-green: #3A5A40;
      --sand-gold: #C4A97D;
      --white: #FFFFFF;
      --text-body: #2C2C2C;
      --text-muted: #6c6c6c;
      --border-light: #e0dcd5;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 6px 20px rgba(0,0,0,0.08);
      --radius-sm: 6px;
      --radius-md: 8px;
      --transition: 0.25s ease;
      --nav-width: 240px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'Noto Sans SC', sans-serif;
      background-color: var(--warm-lime);
      color: var(--text-body);
      margin: 0;
      line-height: 1.75;
      font-weight: 400;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      display: flex;
      flex-direction: row;
      min-height: 100vh;
    }

    h1, h2, h3, h4 {
      font-family: 'Noto Sans SC', sans-serif;
      color: var(--charcoal);
    }

    .inter-font {
      font-family: 'Inter', sans-serif;
    }

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

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

    /* 左侧竖向导航 (桌面) */
    .side-nav {
      width: var(--nav-width);
      height: 100vh;
      position: fixed;
      top: 0;
      left: 0;
      background-color: var(--white);
      border-right: 1px solid var(--border-light);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      padding: 2rem 1.5rem;
      z-index: 1050;
      transition: transform 0.3s ease;
    }

    .logo-area {
      margin-bottom: 2.5rem;
    }

    .logo-text {
      font-size: 28px;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--charcoal);
      line-height: 1.2;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo-text .bridge-icon {
      color: var(--burgundy);
      font-size: 32px;
    }

    .nav-list {
      list-style: none;
      padding: 0;
      margin: 0;
      flex: 1;
    }

    .nav-item {
      margin-bottom: 12px;
    }

    .nav-link {
      display: flex;
      align-items: center;
      font-size: 15px;
      font-weight: 400;
      color: var(--charcoal);
      padding: 8px 12px;
      border-radius: 4px;
      transition: color 0.2s, transform 0.2s, background-color 0.2s;
      position: relative;
    }

    .nav-link:hover {
      color: var(--burgundy);
      transform: translateX(4px);
      background-color: rgba(139, 46, 58, 0.03);
    }

    .nav-link.active {
      font-weight: 600;
      color: var(--burgundy);
      background-color: transparent;
    }

    .nav-link.active::before {
      content: '';
      position: absolute;
      left: -16px;
      top: 8px;
      bottom: 8px;
      width: 3px;
      background-color: var(--burgundy);
      border-radius: 2px;
    }

    .bottom-utils {
      margin-top: auto;
    }

    .lang-switch {
      display: flex;
      gap: 12px;
      margin-bottom: 20px;
      font-size: 13px;
      color: var(--text-muted);
    }

    .lang-switch span {
      cursor: default;
      font-weight: 500;
    }

    .lang-switch span.active-lang {
      color: var(--burgundy);
      font-weight: 600;
    }

    .social-icons {
      display: flex;
      gap: 18px;
      font-size: 18px;
      color: #7a7a7a;
    }

    .social-icons i {
      transition: color 0.2s;
      cursor: default;
    }

    .social-icons i:hover {
      color: var(--burgundy);
    }

    /* 右侧主内容区 */
    .main-content {
      margin-left: var(--nav-width);
      width: calc(100% - var(--nav-width));
      background-color: var(--warm-lime);
    }

    /* 移动端顶部导航 */
    .mobile-nav {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 60px;
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
      align-items: center;
      justify-content: space-between;
      padding: 0 1.5rem;
      z-index: 1060;
    }

    .mobile-logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--charcoal);
    }

    .hamburger {
      font-size: 24px;
      color: var(--charcoal);
      cursor: pointer;
    }

    .mobile-menu-overlay {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: var(--warm-lime);
      z-index: 1070;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2rem;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }

    .mobile-menu-overlay.open {
      transform: translateX(0);
    }

    .mobile-close {
      position: absolute;
      top: 20px;
      right: 25px;
      font-size: 28px;
      color: var(--charcoal);
    }

    /* 通用区块 */
    .section-padding {
      padding: 100px 0;
    }

    .container-custom {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
    }

    h2 {
      font-size: 32px;
      font-weight: 600;
      margin-bottom: 40px;
      letter-spacing: 0;
      line-height: 1.3;
    }

    h3 {
      font-size: 20px;
      font-weight: 500;
      line-height: 1.4;
    }

    .btn-primary-custom {
      background-color: var(--burgundy);
      border: none;
      color: white;
      font-weight: 500;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      transition: background-color 0.25s, transform 0.25s;
      display: inline-block;
      text-align: center;
    }

    .btn-primary-custom:hover {
      background-color: var(--burgundy-dark);
      transform: scale(1.03);
      color: white;
    }

    .btn-outline-custom {
      border: 1.5px solid var(--fir-green);
      color: var(--fir-green);
      background: transparent;
      font-weight: 500;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      transition: all 0.25s;
    }

    .btn-outline-custom:hover {
      background-color: var(--fir-green);
      color: white;
    }

    .card-custom {
      background: var(--white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      padding: 28px;
      transition: var(--transition);
      border: none;
      height: 100%;
    }

    .card-custom:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }

    /* Hero区域 */
    .hero-section {
      min-height: 85vh;
      display: flex;
      align-items: center;
      background-color: var(--warm-lime);
    }

    .hero-image {
      width: 100%;
      height: 500px;
      object-fit: cover;
      border-radius: var(--radius-md);
      box-shadow: 0 10px 25px rgba(0,0,0,0.05);
    }

    /* 瀑布流案例 */
    .masonry-grid {
      column-count: 3;
      column-gap: 24px;
    }

    .masonry-item {
      break-inside: avoid;
      margin-bottom: 24px;
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }

    .masonry-item:hover {
      box-shadow: var(--shadow-card-hover);
    }

    .masonry-item img {
      width: 100%;
      height: auto;
      object-fit: cover;
      transition: transform 0.3s;
    }

    .masonry-item:hover img {
      transform: scale(1.03);
    }

    .badge-tag {
      background: var(--burgundy);
      color: white;
      font-size: 12px;
      padding: 4px 10px;
      border-radius: 20px;
      font-weight: 500;
    }

    /* 对比表 */
    .compare-col {
      background: white;
      padding: 2rem;
      border-radius: var(--radius-md);
    }

    .compare-col.right-col {
      background: #faf9f7;
    }

    .divider-vertical {
      width: 1px;
      background: var(--border-light);
      margin: 0 15px;
    }

    /* FAQ */
    .faq-accordion .accordion-button {
      font-weight: 500;
      font-size: 18px;
      background: white;
      color: var(--charcoal);
      box-shadow: none;
      border-bottom: 1px solid var(--border-light);
    }

    .faq-accordion .accordion-button:not(.collapsed) {
      background: white;
      color: var(--burgundy);
      box-shadow: none;
    }

    /* CTA通栏 */
    .cta-banner {
      background: var(--charcoal);
      padding: 80px 0;
    }

    /* 页脚 */
    .footer-section {
      background: var(--charcoal);
      color: var(--warm-lime);
    }

    .footer-link {
      color: #ccc;
      transition: color 0.2s;
    }

    .footer-link:hover {
      color: var(--sand-gold);
    }

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

    @media (max-width: 768px) {
      .side-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 60px;
      }
      .section-padding {
        padding: 60px 0;
      }
      h2 {
        font-size: 26px;
      }
      h1 {
        font-size: 32px !important;
      }
      .masonry-grid {
        column-count: 1;
      }
      .hero-section .row {
        flex-direction: column;
      }
    }