/* roulang page: index */
:root {
      --primary: #1E2D2F;
      --primary-soft: #2A3A3C;
      --accent: #FF6B4A;
      --accent-hover: #e85d3a;
      --bg-warm: #FAFAF8;
      --white: #FFFFFF;
      --gray-light: #F5F5F3;
      --text-primary: #1E2D2F;
      --text-body: #4A4A4A;
      --text-muted: #8A8A8A;
      --border-light: #E0E0DD;
      --shadow-card: 0 8px 24px rgba(0,0,0,0.06);
      --shadow-button: 0 4px 12px rgba(255,107,74,0.3);
      --radius-card: 12px;
      --radius-button: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", "Inter", system-ui, sans-serif;
      --transition-base: 0.25s ease-out;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }
    h1, h2, h3 {
      color: var(--text-primary);
      font-weight: 600;
      line-height: 1.3;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      border: none;
      background: none;
      font-family: inherit;
    }
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(255,255,255,0.88);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0,0,0,0.04);
      transition: background 0.3s;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--accent);
      font-weight: 700;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 15px;
      color: var(--text-body);
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover {
      color: var(--accent);
    }
    .btn-nav {
      background: var(--accent);
      color: white !important;
      padding: 10px 24px;
      border-radius: 30px;
      font-weight: 600;
      transition: background 0.2s, transform 0.2s;
    }
    .btn-nav:hover {
      background: var(--accent-hover);
      transform: scale(1.02);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: 0.3s;
    }
    /* 移动端导航 */
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: var(--primary);
      backdrop-filter: blur(16px);
      padding: 32px;
      display: flex;
      flex-direction: column;
      gap: 28px;
      transition: right 0.35s ease;
      z-index: 200;
    }
    .mobile-menu.active {
      right: 0;
    }
    .mobile-menu a {
      color: var(--bg-warm);
      font-size: 20px;
      font-weight: 500;
      border-bottom: 1px solid rgba(255,255,255,0.2);
      padding-bottom: 8px;
    }
    .close-menu {
      align-self: flex-end;
      font-size: 28px;
      color: white;
      background: transparent;
      border: none;
    }
    /* Hero */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      margin-top: 72px;
      background-attachment: fixed;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(30,45,47,0.75) 0%, rgba(30,45,47,0.35) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      gap: 40px;
      flex-wrap: wrap;
    }
    .hero-text {
      flex: 1 1 500px;
      color: white;
    }
    .hero h1 {
      font-size: clamp(36px, 5vw, 56px);
      font-weight: 700;
      color: white;
      margin-bottom: 20px;
      line-height: 1.2;
    }
    .hero-sub {
      font-size: 1.25rem;
      margin-bottom: 32px;
      color: rgba(255,255,255,0.9);
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      font-weight: 600;
      font-size: 1rem;
      padding: 16px 40px;
      border-radius: 30px;
      display: inline-block;
      transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
      box-shadow: var(--shadow-button);
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.03);
    }
    .hero-visual {
      flex: 1 1 400px;
      display: flex;
      justify-content: center;
    }
    .section {
      padding: 100px 0;
    }
    .section-dark {
      background: var(--primary);
      color: white;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 600;
      margin-bottom: 16px;
      color: var(--text-primary);
    }
    .section-dark .section-title {
      color: white;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      margin-top: 48px;
    }
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      transition: transform 0.25s ease, box-shadow 0.25s;
      border: 1px solid var(--border-light);
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card);
    }
    .icon-accent {
      color: var(--accent);
      font-size: 28px;
      margin-bottom: 20px;
    }
    .pain-card {
      background: #fff;
      border-left: 4px solid var(--accent);
    }
    .stats-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 32px;
      justify-content: space-around;
      text-align: center;
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent);
    }
    .testimonial-card {
      background: var(--gray-light);
      padding: 32px;
      border-radius: var(--radius-card);
      border-left: 5px solid var(--accent);
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-body);
      margin-top: 8px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      color: #ccc;
    }
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .container { padding: 0 20px; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .grid-3 { grid-template-columns: 1fr; }
      .hero { background-attachment: scroll; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .section { padding: 70px 0; }
    }
    @media (max-width: 480px) {
      .footer-grid { grid-template-columns: 1fr; }
    }