/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary: #D32F2F;
      --primary-dark: #B71C1C;
      --secondary-gold: #FFC107;
      --dark: #212121;
      --deep-bg: #1B1B1B;
      --gray-light: #F5F5F5;
      --white: #FFFFFF;
      --card-bg: #FFFFFF;
      --text-soft: #757575;
      --border-light: #E0E0E0;
      --radius-sm: 8px;
      --radius-md: 12px;
      --shadow-card: 0 8px 24px rgba(0, 0, 0, 0.06);
      --shadow-hover: 0 12px 32px rgba(0, 0, 0, 0.12);
      --font-heading: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-data: "DIN Alternate", "Oswald", "PingFang SC", sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-heading);
      background: #FAFAFA;
      color: var(--dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    /* ----- 导航系统 (沉浸式, sticky) ----- */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 999;
      transition: background 0.3s ease, box-shadow 0.3s ease;
      background: transparent;
      padding: 16px 0;
    }
    .header.scrolled {
      background: var(--white);
      box-shadow: 0 4px 16px rgba(0,0,0,0.05);
      padding: 10px 0;
    }
    .header.scrolled .nav-container .logo,
    .header.scrolled .nav-links a {
      color: var(--dark);
    }
    .header.scrolled .nav-links a:hover {
      color: var(--primary);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 28px;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      letter-spacing: 2px;
      color: #fff;
      transition: color 0.2s;
      display: flex;
      align-items: center;
      gap: 0.25rem;
    }
    .logo i {
      color: var(--secondary-gold);
      font-size: 2rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2.2rem;
    }
    .nav-links a {
      font-weight: 500;
      color: rgba(255,255,255,0.9);
      transition: color 0.2s;
      font-size: 0.98rem;
    }
    .nav-links a:hover {
      color: var(--secondary-gold);
    }
    .nav-cta {
      background: var(--primary);
      color: #fff !important;
      padding: 0.55rem 1.8rem;
      border-radius: 30px;
      font-weight: 600;
      margin-left: 1rem;
      transition: background 0.3s, transform 0.2s;
      border: none;
    }
    .nav-cta:hover {
      background: var(--primary-dark);
      transform: scale(1.03);
    }
    .hamburger {
      display: none;
      background: transparent;
      border: none;
      font-size: 1.8rem;
      color: #fff;
      cursor: pointer;
      transition: color 0.2s;
    }
    .header.scrolled .hamburger {
      color: var(--dark);
    }
    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(0,0,0,0.95);
      backdrop-filter: blur(8px);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2.4rem;
      transform: translateY(-100%);
      opacity: 0;
      transition: all 0.4s ease;
      z-index: 1000;
    }
    .mobile-menu.active {
      transform: translateY(0);
      opacity: 1;
    }
    .mobile-menu a {
      font-size: 1.6rem;
      color: #fff;
      font-weight: 600;
    }
    .mobile-close {
      position: absolute;
      top: 28px;
      right: 32px;
      font-size: 2.4rem;
      color: #fff;
      background: none;
      border: none;
      cursor: pointer;
    }
    /* ----- Hero 区域 ----- */
    .hero {
      min-height: 92vh;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      display: flex;
      align-items: center;
      position: relative;
      color: #fff;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: rgba(0,0,0,0.58);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 680px;
      margin-left: 6%;
      padding: 0 24px;
      margin-top: 0rem;
    }
    .hero h1 {
      font-size: clamp(2.6rem, 5.5vw, 4.4rem);
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 1.2rem;
      text-shadow: 0 4px 14px rgba(0,0,0,0.5);
      letter-spacing: 1px;
    }
    .hero p {
      font-size: 1.2rem;
      font-weight: 300;
      margin-bottom: 2.5rem;
      color: rgba(255,255,255,0.9);
    }
    .btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 1.2rem;
    }
    .btn-primary {
      background: var(--primary);
      border: none;
      color: #fff;
      font-weight: 700;
      padding: 0.9rem 2.2rem;
      border-radius: 40px;
      font-size: 1.1rem;
      cursor: pointer;
      transition: 0.25s ease;
      text-align: center;
      box-shadow: 0 6px 18px rgba(211,47,47,0.3);
    }
    .btn-primary:hover {
      background: #b71c1c;
      transform: translateY(-2px);
      box-shadow: 0 10px 22px rgba(183,28,28,0.4);
    }
    .btn-outline-light {
      background: transparent;
      border: 2px solid #fff;
      color: #fff;
      font-weight: 600;
      padding: 0.85rem 2.2rem;
      border-radius: 40px;
      transition: 0.3s;
    }
    .btn-outline-light:hover {
      background: #fff;
      color: var(--primary);
      border-color: #fff;
    }
    /* ----- 板块共用 ----- */
    section {
      padding: 5rem 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 3rem;
    }
    .section-title h2 {
      font-size: 2.3rem;
      font-weight: 700;
      color: var(--dark);
      margin-bottom: 0.4rem;
    }
    .section-title .sub {
      color: var(--text-soft);
      font-size: 1.1rem;
    }
    .pain-grid, .service-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 2rem;
    }
    .card {
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      background: rgba(211,47,47,0.08);
      width: 56px;
      height: 56px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 1.2rem;
      color: var(--primary);
      font-size: 1.8rem;
    }
    /* 成果数据区 (深色) */
    .stats-section {
      background: var(--deep-bg);
      color: #fff;
    }
    .stats-grid {
      display: flex;
      flex-wrap: wrap;
      justify-content: space-around;
      gap: 2.5rem;
      text-align: center;
    }
    .stat-item .stat-number {
      font-size: 3.2rem;
      font-weight: 800;
      font-family: var(--font-data);
      color: var(--secondary-gold);
    }
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 2rem;
    }
    .quote-card {
      background: #fff;
      border-left: 5px solid var(--primary);
      padding: 1.6rem;
      border-radius: 0 var(--radius-md) var(--radius-md) 0;
      box-shadow: var(--shadow-card);
    }
    .faq-item {
      border-bottom: 1px solid #eee;
    }
    .faq-question {
      font-weight: 700;
      padding: 1.2rem 0;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: #fafafa;
      padding: 0 1rem;
    }
    .faq-item.active .faq-answer {
      max-height: 160px;
      padding: 1rem;
    }
    .footer {
      background: #1B1B1B;
      color: #ddd;
      padding: 4rem 1.5rem 2rem;
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .hero-content { margin-left: 0; text-align: center; }
      .btn-group { justify-content: center; }
    }