/* roulang page: index */
:root {
      --deep-stone: #2B2D2A;
      --morning-copper: #C49A6C;
      --warm-limestone: #FAF7F2;
      --dark-bg-start: #2B2D2A;
      --dark-bg-end: #3F423F;
      --text-primary: #1E1E1E;
      --text-secondary: #5C5C5C;
      --text-light: #F5F5F5;
      --accent-mist-green: #7A9A8A;
      --border-light: #EAE7E2;
      --white: #FFFFFF;
      --card-shadow: 0 2px 12px rgba(43, 45, 42, 0.06);
      --card-shadow-hover: 0 8px 24px rgba(43, 45, 42, 0.12);
      --radius-card: 8px;
      --radius-btn: 6px;
      --radius-tag: 4px;
      --font-title: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --transition-smooth: 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-title);
      background-color: var(--warm-limestone);
      color: var(--text-primary);
      line-height: 1.8;
      margin: 0;
      padding: 0;
      overflow-x: hidden;
    }

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

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

    button, input, textarea {
      font-family: inherit;
    }

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

    /* 导航 */
    .navbar-custom {
      background-color: rgba(250, 247, 242, 0.92);
      backdrop-filter: blur(8px);
      height: 72px;
      padding: 0;
      box-shadow: none;
      border-bottom: 1px solid transparent;
      transition: all var(--transition-smooth);
    }

    .navbar-brand {
      font-weight: 700;
      font-size: 20px;
      letter-spacing: 0.04em;
      color: var(--morning-copper) !important;
      padding: 0;
    }

    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary) !important;
      margin-left: 32px;
      padding: 0 !important;
      position: relative;
      letter-spacing: 0.02em;
    }

    .nav-link:first-of-type {
      margin-left: 0;
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--morning-copper) !important;
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background-color: var(--morning-copper);
      transition: width var(--transition-smooth);
    }

    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }

    .navbar-toggler {
      border: none;
      padding: 4px;
      box-shadow: none;
    }

    .navbar-toggler-icon {
      background-image: none;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      width: 24px;
      height: 18px;
      position: relative;
    }

    .navbar-toggler-icon::before,
    .navbar-toggler-icon::after {
      content: '';
      display: block;
      width: 24px;
      height: 2px;
      background-color: var(--deep-stone);
      transition: all 0.3s ease;
      position: absolute;
    }

    .navbar-toggler-icon::before {
      top: 4px;
    }

    .navbar-toggler-icon::after {
      bottom: 4px;
      width: 18px;
    }

    .navbar-toggler[aria-expanded="true"] .navbar-toggler-icon::before {
      top: 8px;
      transform: rotate(45deg);
    }

    .navbar-toggler[aria-expanded="true"] .navbar-toggler-icon::after {
      bottom: 8px;
      width: 24px;
      transform: rotate(-45deg);
    }

    @media (max-width: 991px) {
      .navbar-collapse {
        background-color: var(--warm-limestone);
        padding: 20px;
        border-radius: 0 0 var(--radius-card) var(--radius-card);
        box-shadow: var(--card-shadow);
        margin-top: 10px;
      }
      .nav-link {
        margin-left: 0;
        margin-bottom: 12px;
        padding: 8px 0 !important;
      }
      .navbar-custom {
        height: 60px;
      }
    }

    /* Hero */
    .hero-section {
      padding: 120px 0 80px;
      background-color: var(--warm-limestone);
      background-image: radial-gradient(circle at 30% 40%, rgba(255,255,255,0.4) 0%, rgba(250,247,242,0) 70%);
    }

    .hero-title {
      font-weight: 700;
      font-size: 52px;
      line-height: 1.2;
      letter-spacing: -0.02em;
      color: var(--deep-stone);
      margin-bottom: 20px;
    }

    .hero-subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      max-width: 420px;
      margin-bottom: 32px;
    }

    .btn-primary-custom {
      background-color: var(--morning-copper);
      border: none;
      color: white;
      font-weight: 600;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      transition: background-color var(--transition-smooth);
    }

    .btn-primary-custom:hover {
      background-color: #B0885A;
      color: white;
    }

    .btn-outline-custom {
      background: transparent;
      border: 1.5px solid var(--morning-copper);
      color: var(--morning-copper);
      font-weight: 600;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      transition: all var(--transition-smooth);
    }

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

    .hero-image {
      border-radius: 12px;
      box-shadow: 0 12px 30px rgba(43,45,42,0.08);
      width: 100%;
      height: auto;
      object-fit: cover;
    }

    @media (max-width: 768px) {
      .hero-title {
        font-size: 36px;
      }
      .hero-section {
        padding: 100px 0 60px;
      }
      .hero-subtitle {
        font-size: 16px;
      }
    }

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

    .section-title {
      font-weight: 600;
      font-size: 38px;
      color: var(--deep-stone);
      margin-bottom: 16px;
      letter-spacing: -0.01em;
    }

    .section-subtitle {
      color: var(--text-secondary);
      font-size: 17px;
      margin-bottom: 48px;
    }

    @media (max-width: 768px) {
      .section-padding {
        padding: 60px 0;
      }
      .section-title {
        font-size: 28px;
      }
    }

    /* 卡片 */
    .advantage-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--card-shadow);
      transition: all var(--transition-smooth);
      height: 100%;
    }

    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-shadow-hover);
      border-color: var(--morning-copper);
    }

    .icon-circle {
      width: 48px;
      height: 48px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--morning-copper);
      font-size: 32px;
      margin-bottom: 20px;
    }

    .card-title {
      font-weight: 600;
      font-size: 22px;
      margin-bottom: 12px;
      color: var(--deep-stone);
    }

    .card-text {
      color: var(--text-secondary);
      font-size: 16px;
      line-height: 1.7;
    }

    .text-link {
      color: var(--morning-copper);
      font-weight: 500;
      display: inline-block;
      margin-top: 16px;
      transition: all var(--transition-smooth);
    }

    .text-link:hover {
      text-decoration: underline;
      text-underline-offset: 4px;
      color: #B0885A;
    }

    /* 业务版图卡片网格 */
    .biz-card {
      background: var(--white);
      border-radius: var(--radius-card);
      border: 1px solid var(--border-light);
      padding: 28px;
      box-shadow: var(--card-shadow);
      transition: all var(--transition-smooth);
    }

    .biz-card:hover {
      box-shadow: var(--card-shadow-hover);
      border-color: var(--morning-copper);
    }

    /* 场景图文交错 */
    .scene-image {
      border-radius: var(--radius-card);
      width: 100%;
      height: auto;
      aspect-ratio: 4/3;
      object-fit: cover;
    }

    .tag-list {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      margin-top: 16px;
    }

    .tag {
      border: 1px solid var(--morning-copper);
      color: var(--morning-copper);
      padding: 4px 12px;
      border-radius: var(--radius-tag);
      font-size: 13px;
      letter-spacing: 0.04em;
      background: transparent;
    }

    /* 数据里程碑 */
    .stat-number {
      font-weight: 700;
      font-size: 42px;
      color: var(--morning-copper);
      line-height: 1.2;
    }

    .stat-label {
      color: var(--text-secondary);
      font-size: 16px;
    }

    .dark-bg {
      background: linear-gradient(135deg, var(--dark-bg-start), var(--dark-bg-end));
      color: var(--text-light);
    }

    /* FAQ */
    .accordion-button {
      font-weight: 600;
      font-size: 18px;
      color: var(--text-primary);
      background-color: transparent;
      box-shadow: none;
      padding: 20px 0;
      border-bottom: 1px solid var(--border-light);
    }

    .accordion-button:not(.collapsed) {
      color: var(--morning-copper);
      background-color: transparent;
      box-shadow: none;
    }

    .accordion-button::after {
      background-image: none;
      content: '+';
      font-size: 24px;
      color: var(--morning-copper);
      font-weight: 400;
      transition: transform 0.3s;
    }

    .accordion-button:not(.collapsed)::after {
      content: '−';
      transform: rotate(0deg);
    }

    .accordion-item {
      border: none;
      background: transparent;
    }

    .accordion-body {
      color: var(--text-secondary);
      padding-bottom: 20px;
      font-size: 16px;
    }

    /* CTA */
    .cta-section {
      background-color: var(--warm-limestone);
      border-top: 1px solid var(--border-light);
    }

    .form-control-custom {
      border: 1px solid #D0D0D0;
      border-radius: var(--radius-btn);
      padding: 12px 16px;
      background: white;
    }

    .form-control-custom:focus {
      border-color: var(--morning-copper);
      box-shadow: none;
    }

    /* 页脚 */
    .footer {
      background-color: var(--deep-stone);
      color: #D0D0D0;
      padding: 60px 0 20px;
    }

    .footer-brand {
      color: var(--morning-copper);
      font-weight: 700;
      font-size: 18px;
    }

    .footer a {
      color: #D0D0D0;
      transition: color var(--transition-smooth);
    }

    .footer a:hover {
      color: var(--morning-copper);
    }

    .footer-bottom {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 20px;
      font-size: 13px;
    }