/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary: #E43D2A;
      --dark: #1A1A2E;
      --warm-bg: #F5F0E8;
      --accent: #00C9A7;
      --text-body: #3D3D50;
      --text-muted: #5A5A6E;
      --white: #FFFFFF;
      --border-light: rgba(26, 26, 46, 0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 4px 12px rgba(26, 26, 46, 0.06);
      --shadow-hover: 0 12px 28px rgba(228, 61, 42, 0.14);
      --transition: 0.25s ease;
      --nav-height: 64px;
      --nav-height-mobile: 56px;
    }

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

    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--warm-bg);
      color: var(--text-body);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

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

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* 栅格占位 */
    .grid {
      display: grid;
      gap: 24px;
    }

    /* 排版预设 */
    h1, h2, h3 {
      font-weight: 700;
      color: var(--dark);
    }
    h1 {
      font-size: 48px;
      line-height: 1.2;
      letter-spacing: -0.5px;
    }
    h2 {
      font-size: 36px;
      line-height: 1.25;
      letter-spacing: 0;
      margin-bottom: 1rem;
    }
    h3 {
      font-size: 22px;
      line-height: 1.35;
      letter-spacing: 0.2px;
    }
    p {
      font-size: 16px;
      line-height: 1.8;
      color: var(--text-body);
    }
    .text-muted {
      color: var(--text-muted);
    }
    .section {
      padding: 100px 0;
    }

    /* ----- 导航系统 ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(245, 240, 232, 0.85);
      backdrop-filter: blur(8px);
      z-index: 1000;
      transition: background 0.3s, box-shadow 0.3s;
      display: flex;
      align-items: center;
    }
    .site-header.scrolled {
      background: #ffffff;
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      letter-spacing: -0.2px;
      color: var(--dark);
    }
    .logo span {
      color: var(--primary);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--dark);
      position: relative;
      padding: 4px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .btn-nav {
      background: var(--primary);
      color: white;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      letter-spacing: 0.3px;
      white-space: nowrap;
    }
    .btn-nav:hover {
      background: var(--dark);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--dark);
      border-radius: 2px;
    }
    .mobile-drawer {
      position: fixed;
      top: 0;
      right: -100%;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: var(--dark);
      padding: 24px;
      display: flex;
      flex-direction: column;
      gap: 32px;
      transition: right 0.3s ease;
      z-index: 1001;
    }
    .mobile-drawer.open {
      right: 0;
    }
    .drawer-close {
      align-self: flex-end;
      font-size: 24px;
      color: white;
      background: none;
      border: none;
    }
    .drawer-nav {
      display: flex;
      flex-direction: column;
      gap: 24px;
      list-style: none;
    }
    .drawer-nav a {
      font-size: 18px;
      color: white;
      font-weight: 500;
    }

    /* ----- 首屏 Hero ----- */
    .hero {
      background: linear-gradient(135deg, #1A1A2E 0%, #E43D2A 100%);
      position: relative;
      overflow: hidden;
      min-height: 90vh;
      display: flex;
      align-items: center;
      padding-top: var(--nav-height);
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background-image: repeating-linear-gradient(45deg, rgba(255,255,255,0.03) 0px, rgba(255,255,255,0.03) 2px, transparent 2px, transparent 8px);
      pointer-events: none;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
      position: relative;
      z-index: 2;
    }
    .hero-content h1 {
      color: white;
      margin-bottom: 20px;
    }
    .hero-content h1 span {
      color: #FF8A7A;
    }
    .hero-sub {
      font-size: 18px;
      color: rgba(245, 240, 232, 0.8);
      margin-bottom: 32px;
      max-width: 450px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      transition: background 0.25s;
    }
    .btn-primary:hover {
      background: var(--dark);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid rgba(255,255,255,0.7);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: rgba(255,255,255,0.1);
    }
    .hero-image img {
      border-radius: 16px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    }

    /* ----- 通用卡片与布局 ----- */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .grid-2 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(3, 1fr); }
    .grid-4 { grid-template-columns: repeat(4, 1fr); }

    /* 痛点区图文交替 */
    .pain-row {
      display: flex;
      align-items: center;
      gap: 40px;
      margin-bottom: 60px;
    }
    .pain-row.reverse {
      flex-direction: row-reverse;
    }
    .pain-text {
      flex: 1;
    }
    .pain-visual {
      flex: 1;
      background: #f0ebe2;
      border-radius: 16px;
      overflow: hidden;
    }
    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(228,61,42,0.1);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 24px;
      margin-bottom: 16px;
    }

    /* 解决方案卡片 */
    .solution-card i {
      font-size: 28px;
      color: var(--primary);
    }

    /* 数据区 */
    .data-band {
      background: var(--dark);
      padding: 80px 0;
    }
    .stats-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 32px;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      font-family: 'DIN Alternate', 'Inter', sans-serif;
      color: var(--accent);
    }
    .stat-label {
      color: rgba(245,240,232,0.8);
      margin-top: 8px;
    }

    /* 证言卡片 */
    .testimonial-card {
      background: white;
      padding: 28px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
    }
    .testimonial-card:hover {
      border-left: 4px solid var(--primary);
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-muted);
    }
    .faq-item.active .faq-answer {
      max-height: 150px;
      margin-top: 12px;
    }

    /* 最终CTA */
    .cta-band {
      background: var(--primary);
      text-align: center;
      padding: 80px 0;
    }
    .btn-light {
      background: white;
      color: var(--primary);
      padding: 16px 40px;
      border-radius: var(--radius-btn);
      font-weight: 700;
    }
    .btn-light:hover {
      background: var(--dark);
      color: white;
    }

    /* 页脚 */
    .footer {
      background: var(--dark);
      color: rgba(245,240,232,0.8);
      padding: 50px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 30px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      h1 { font-size: 40px; }
      .hero-grid { grid-template-columns: 1fr; }
      .pain-row, .pain-row.reverse { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .grid-3, .grid-4 { grid-template-columns: 1fr; }
      .grid-2 { grid-template-columns: 1fr; }
      .section { padding: 60px 0; }
      .footer-grid { grid-template-columns: 1fr; }
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      .btn-group { flex-direction: column; align-items: flex-start; }
    }