/* roulang page: index */
:root {
      --brand-black: #0A0E17;
      --accent-red: #E62B1E;
      --deep-red: #C41E13;
      --bg-warm: #F5F3EE;
      --card-white: #FFFFFF;
      --text-body: #2C2C2C;
      --text-muted: #6B6B6B;
      --text-on-dark: #FFFFFF;
      --text-on-dark-muted: #B0B0B0;
      --border-light: #E0DDD6;
      --success-green: #1A8A3F;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --shadow-card: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 30px rgba(0,0,0,0.08);
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, -apple-system, sans-serif;
      --transition: 0.2s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-body);
      line-height: 1.75;
      margin: 0;
      padding-top: 72px;
    }

    /* 基础重置 */
    a {
      color: var(--accent-red);
      text-decoration: none;
      transition: color var(--transition);
    }
    a:hover {
      color: var(--deep-red);
      text-decoration: underline;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      font-family: var(--font-sans);
      transition: all var(--transition);
    }

    /* 自定义导航条 - 搜索主导 */
    .navbar {
      background-color: var(--brand-black);
      height: 72px;
      padding: 0 1.5rem;
      box-shadow: 0 4px 12px rgba(0,0,0,0.2);
      z-index: 1000;
    }
    .navbar-brand {
      font-weight: 800;
      font-size: 1.5rem;
      letter-spacing: -0.02em;
      color: var(--text-on-dark) !important;
      display: flex;
      align-items: center;
    }
    .navbar-brand span {
      color: var(--accent-red);
      margin-right: 4px;
    }
    .search-form {
      display: flex;
      align-items: center;
      flex: 1;
      max-width: 420px;
      margin: 0 2rem;
    }
    .search-input-group {
      position: relative;
      width: 100%;
    }
    .search-input-group .form-control {
      height: 44px;
      border-radius: 50px;
      border: none;
      padding-left: 2.8rem;
      background-color: var(--card-white);
      box-shadow: none;
      font-size: 0.9rem;
      color: var(--text-body);
      transition: all 0.25s;
    }
    .search-input-group .form-control:focus {
      border: 1px solid var(--accent-red);
      box-shadow: 0 0 0 3px rgba(230,43,30,0.2);
      background-color: white;
    }
    .search-input-group .search-icon {
      position: absolute;
      left: 16px;
      top: 50%;
      transform: translateY(-50%);
      color: #999;
      font-size: 1rem;
      z-index: 5;
    }
    .navbar-nav .nav-link {
      color: var(--text-on-dark-muted) !important;
      font-size: 0.9rem;
      font-weight: 500;
      padding: 0.5rem 1rem !important;
      transition: color 0.2s;
      white-space: nowrap;
    }
    .navbar-nav .nav-link:hover {
      color: var(--text-on-dark) !important;
    }
    .btn-cta-nav {
      background-color: var(--accent-red);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.5rem 1.5rem;
      font-weight: 600;
      font-size: 0.9rem;
      border: none;
      white-space: nowrap;
    }
    .btn-cta-nav:hover {
      background-color: var(--deep-red);
      color: white;
    }
    .navbar-toggler {
      border-color: rgba(255,255,255,0.4);
      color: white;
    }
    .navbar-toggler-icon {
      background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(255,255,255,0.8)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
    }

    /* 通用板块 */
    section {
      padding: 5rem 0;
      scroll-margin-top: 72px;
    }
    .section-dark {
      background-color: var(--brand-black);
      color: var(--text-on-dark);
    }
    .section-light {
      background-color: var(--bg-warm);
    }
    .section-white {
      background-color: white;
    }

    .container-custom {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      letter-spacing: -0.01em;
    }
    h1 {
      font-size: 2.8rem;
      font-weight: 900;
      line-height: 1.15;
      color: var(--brand-black);
    }
    h2 {
      font-size: 2rem;
      font-weight: 800;
      line-height: 1.25;
      color: var(--brand-black);
      margin-bottom: 1rem;
    }
    .section-dark h2, .section-dark h3 {
      color: white;
    }
    .title-underline {
      width: 50px;
      height: 4px;
      background-color: var(--accent-red);
      margin: 0.8rem auto 2rem;
    }

    /* 按钮覆写 */
    .btn-primary-red {
      background-color: var(--accent-red);
      border: none;
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      font-weight: 600;
      box-shadow: none;
    }
    .btn-primary-red:hover {
      background-color: var(--deep-red);
      color: white;
    }
    .btn-outline-dark-custom {
      border: 2px solid var(--brand-black);
      background: transparent;
      color: var(--brand-black);
      border-radius: var(--radius-btn);
      padding: 0.7rem 2rem;
      font-weight: 600;
    }
    .btn-outline-dark-custom:hover {
      background-color: var(--brand-black);
      color: white;
    }

    /* 卡片 */
    .feature-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      transition: all 0.25s;
      height: 100%;
      border: none;
    }
    .feature-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-3px);
    }
    .feature-icon {
      font-size: 2.4rem;
      color: var(--accent-red);
      margin-bottom: 1.2rem;
    }

    /* 案例瀑布流 */
    .masonry-grid {
      column-count: 3;
      column-gap: 1.5rem;
    }
    .masonry-item {
      break-inside: avoid;
      margin-bottom: 1.5rem;
      border-radius: var(--radius-card);
      overflow: hidden;
      position: relative;
      background: #2c2c2c;
      transition: transform 0.25s;
    }
    .masonry-item img {
      width: 100%;
      display: block;
      transition: transform 0.3s;
    }
    .masonry-item:hover img {
      transform: scale(1.03);
    }
    .masonry-overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      background: linear-gradient(transparent, rgba(0,0,0,0.75));
      padding: 1.5rem 1.2rem 1rem;
      color: white;
    }
    .masonry-overlay h4 {
      font-size: 1.2rem;
      font-weight: 700;
      margin-bottom: 0.2rem;
    }
    .badge-accent {
      background-color: var(--accent-red);
      color: white;
      font-size: 0.7rem;
      padding: 0.2rem 0.6rem;
      border-radius: 20px;
    }

    /* 对比表 */
    .compare-col {
      padding: 2rem;
      background: white;
      border-radius: var(--radius-card);
    }
    .compare-divider {
      width: 1px;
      background: var(--border-light);
    }

    /* 信任数据 */
    .trust-number {
      font-size: 2.8rem;
      font-weight: 900;
      color: var(--accent-red);
      line-height: 1.2;
    }

    /* FAQ手风琴覆写 */
    .accordion-button {
      font-weight: 700;
      font-size: 1.1rem;
      color: var(--brand-black);
      background-color: white;
      border-radius: var(--radius-card) !important;
      box-shadow: none;
      padding: 1.2rem 1.5rem;
    }
    .accordion-button:not(.collapsed) {
      background-color: white;
      color: var(--brand-black);
      box-shadow: none;
      border-bottom: 1px solid var(--border-light);
    }
    .accordion-button:focus {
      border-color: var(--accent-red);
      box-shadow: 0 0 0 2px rgba(230,43,30,0.25);
    }
    .accordion-item {
      border: none;
      margin-bottom: 0.8rem;
      border-radius: var(--radius-card);
      background: white;
    }

    /* 表单 */
    .form-control-custom {
      border-radius: var(--radius-input);
      border: 1px solid var(--border-light);
      padding: 0.7rem 1rem;
      background: white;
    }
    .form-control-custom:focus {
      border-color: var(--accent-red);
      box-shadow: 0 0 0 2px rgba(230,43,30,0.15);
    }

    footer a {
      color: var(--text-on-dark-muted);
    }
    footer a:hover {
      color: white;
    }

    @media (max-width: 992px) {
      h1 { font-size: 2.2rem; }
      .masonry-grid { column-count: 2; }
      .search-form { margin: 0.5rem 0; max-width: 100%; }
      .navbar .container { flex-wrap: wrap; }
    }
    @media (max-width: 768px) {
      section { padding: 3rem 0; }
      .masonry-grid { column-count: 1; }
      .compare-divider { display: none; }
      .navbar-brand { font-size: 1.2rem; }
    }