/* roulang page: index */
/* ----- 设计变量 & 全局重置 ----- */
    :root {
      --primary-bg: #1A1A1A;
      --secondary-bg: #141414;
      --card-light: #F5F0E8;
      --gold: #C8A96E;
      --gold-hover: #B8944A;
      --gold-glow: rgba(200, 169, 110, 0.4);
      --gold-soft: rgba(200, 169, 110, 0.15);
      --text-primary: #2C2C2C;
      --text-on-dark: #EAE5DA;
      --text-muted: #6B6B6B;
      --text-dark-muted: #9A958A;
      --accent-rose: #A05A5A;
      --white-warm: #F5F0E8;
      --border-gold: rgba(200, 169, 110, 0.25);
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.25);
      --transition: all 0.25s ease;
      --font-sans: 'Noto Sans SC', 'Inter', system-ui, -apple-system, sans-serif;
      --max-width: 1280px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--primary-bg);
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--primary-bg);
      color: var(--text-on-dark);
      line-height: 1.7;
      font-weight: 400;
      -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: none;
      transition: var(--transition);
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    /* 板块通用间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 70px 0;
      }
    }

    /* ----- 暗色霓虹导航 ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background-color: rgba(26, 26, 26, 0.92);
      backdrop-filter: blur(12px);
      border-bottom: 2px solid transparent;
      box-shadow: 0 1px 0 var(--gold-glow);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--gold);
      letter-spacing: 1px;
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--gold);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-link {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-on-dark);
      position: relative;
      padding: 8px 0;
      letter-spacing: 0.3px;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--gold);
      box-shadow: 0 0 8px var(--gold-glow);
      transition: width 0.2s ease;
    }
    .nav-link:hover {
      color: var(--gold);
    }
    .nav-link:hover::after {
      width: 20px;
    }
    .nav-link.active {
      color: var(--gold);
    }
    .nav-link.active::after {
      width: 20px;
      background: var(--gold);
      box-shadow: 0 0 12px var(--gold);
    }
    .nav-cta {
      background: var(--gold);
      color: #1A1A1A;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      letter-spacing: 0.5px;
      margin-left: 12px;
      box-shadow: 0 4px 10px rgba(200,169,110,0.3);
    }
    .nav-cta:hover {
      background: var(--gold-hover);
      box-shadow: 0 6px 18px rgba(200,169,110,0.5);
      transform: translateY(-1px);
    }
    /* 汉堡菜单 */
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text-on-dark);
      transition: 0.2s;
    }
    @media (max-width: 1024px) {
      .nav-menu {
        gap: 22px;
      }
    }
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 72px;
        right: 0;
        background: rgba(20,20,20,0.96);
        backdrop-filter: blur(20px);
        flex-direction: column;
        width: 260px;
        height: calc(100vh - 72px);
        padding: 40px 30px;
        align-items: flex-start;
        gap: 28px;
        transform: translateX(100%);
        transition: transform 0.3s ease;
        box-shadow: -5px 0 20px rgba(0,0,0,0.5);
      }
      .nav-menu.active-mobile {
        transform: translateX(0);
      }
      .hamburger {
        display: flex;
      }
      .nav-cta {
        margin-left: 0;
        width: 100%;
        text-align: center;
      }
    }

    /* -----  Hero 首屏 ----- */
    .hero {
      height: 100vh;
      min-height: 700px;
      display: flex;
      align-items: center;
      background-color: var(--primary-bg);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      position: relative;
      padding-top: var(--nav-height);
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 20% 30%, rgba(26,26,26,0.7) 0%, #1A1A1A 90%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      width: 100%;
    }
    .hero-text {
      flex: 1;
    }
    .hero-title {
      font-size: 3.5rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-on-dark);
      margin-bottom: 20px;
    }
    .hero-title span {
      color: var(--gold);
      position: relative;
    }
    .hero-title span::after {
      content: '';
      position: absolute;
      bottom: 5px;
      left: 0;
      width: 100%;
      height: 4px;
      background: var(--gold);
      opacity: 0.5;
    }
    .hero-desc {
      font-size: 1.2rem;
      color: rgba(234,229,218,0.8);
      max-width: 500px;
      margin-bottom: 32px;
    }
    .hero-cta {
      background: var(--gold);
      color: #1A1A1A;
      padding: 14px 36px;
      font-size: 1.1rem;
      font-weight: 600;
      border-radius: var(--radius-btn);
      display: inline-block;
      box-shadow: 0 6px 18px rgba(200,169,110,0.35);
    }
    .hero-cta:hover {
      background: var(--gold-hover);
      transform: translateY(-3px);
      box-shadow: 0 14px 28px rgba(200,169,110,0.5);
    }
    .hero-visual {
      flex: 0.9;
      display: flex;
      justify-content: center;
    }
    .hero-visual img {
      max-height: 420px;
      border-radius: 24px;
      filter: drop-shadow(0 20px 30px rgba(0,0,0,0.5));
    }
    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
        text-align: center;
      }
      .hero-title {
        font-size: 2.4rem;
      }
      .hero-desc {
        margin: 0 auto 24px;
      }
      .hero-visual img {
        max-height: 260px;
      }
    }

    /* 价值主张 / 功能卡片等通用 */
    .section-title {
      font-size: 2.2rem;
      font-weight: 600;
      color: var(--text-on-dark);
      margin-bottom: 16px;
      text-align: center;
    }
    .section-sub {
      color: var(--text-dark-muted);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 48px;
    }
    .grid-3, .grid-4 {
      display: grid;
      gap: 24px;
    }
    .grid-3 { grid-template-columns: repeat(3, 1fr); }
    .grid-4 { grid-template-columns: repeat(4, 1fr); }
    @media (max-width: 768px) {
      .grid-3, .grid-4 { grid-template-columns: 1fr; }
    }

    .card {
      background: rgba(245,240,232,0.06);
      backdrop-filter: blur(4px);
      border: 1px solid var(--border-gold);
      border-radius: var(--radius-card);
      padding: 32px;
      transition: var(--transition);
    }
    .card-light {
      background: var(--card-light);
      border: 1px solid rgba(200,169,110,0.2);
      color: var(--text-primary);
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--gold);
    }
    .icon-gold {
      color: var(--gold);
      font-size: 2rem;
      margin-bottom: 18px;
    }
    .card h3 {
      font-size: 1.25rem;
      font-weight: 600;
      margin-bottom: 10px;
    }

    /* 场景交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-text {
      flex: 1;
    }
    .scenario-img {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
    }
    @media (max-width: 768px) {
      .scenario-row, .scenario-row.reverse {
        flex-direction: column;
      }
    }

    /* 案例数字 */
    .stat-number {
      font-size: 3.4rem;
      font-weight: 700;
      color: var(--gold);
      line-height: 1.1;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-gold);
      padding: 18px 0;
    }
    .faq-question {
      width: 100%;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: transparent;
      color: var(--text-on-dark);
      font-size: 1.1rem;
      font-weight: 500;
      text-align: left;
      padding: 8px 0;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: #b0a89a;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 10px;
    }

    /* CTA 终极区 */
    .cta-section {
      background: #141414;
      text-align: center;
    }
    .btn-xl {
      background: var(--gold);
      color: #1A1A1A;
      padding: 16px 42px;
      font-size: 1.2rem;
      border-radius: 50px;
      font-weight: 700;
      display: inline-block;
      margin-top: 24px;
    }

    footer {
      background: #0f0f0f;
      padding: 60px 0 30px;
      color: #aaa;
    }