/* roulang page: index */
:root {
      --primary-black: #0B0C10;
      --accent-gold: #C5A059;
      --bg-carbon: #1A1A1D;
      --text-ivory: #F0EFEA;
      --accent-burgundy: #8B2A3C;
      --border-gold-dim: rgba(197, 160, 89, 0.2);
      --border-gold-soft: rgba(197, 160, 89, 0.15);
      --shadow-card: 0 10px 30px -10px rgba(0,0,0,0.5);
      --font-serif: 'Noto Serif SC', 'Source Han Serif SC', serif;
      --font-display: 'Cormorant Garamond', 'Playfair Display', serif;
      --font-sans: 'Inter', 'SF Pro Text', sans-serif;
      --radius-geo: 2px;
      --transition-smooth: 0.4s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      --transition-nav: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-serif);
      background-color: var(--primary-black);
      color: var(--text-ivory);
      line-height: 1.8;
      display: flex;
      min-height: 100vh;
      overflow-x: hidden;
    }
    /* 左侧导航 (桌面) */
    .app-sidebar {
      position: fixed;
      left: 0;
      top: 0;
      height: 100vh;
      width: 80px;
      background-color: var(--primary-black);
      border-right: 1px solid var(--border-gold-soft);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 2rem 0;
      z-index: 1000;
      transition: var(--transition-nav);
      overflow: hidden;
      white-space: nowrap;
    }
    .app-sidebar:hover {
      width: 240px;
    }
    .sidebar-logo {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 100%;
      padding: 0 1rem;
      margin-bottom: 2rem;
    }
    .logo-text {
      font-family: var(--font-display);
      font-weight: 700;
      font-size: 1.8rem;
      color: var(--accent-gold);
      letter-spacing: 0.1em;
      opacity: 0;
      transition: opacity 0.2s;
      white-space: nowrap;
    }
    .app-sidebar:hover .logo-text {
      opacity: 1;
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--accent-gold);
      margin-right: 0.5rem;
    }
    .sidebar-nav {
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
      width: 100%;
      padding: 0 1rem;
    }
    .nav-item {
      display: flex;
      align-items: center;
      gap: 1.2rem;
      color: var(--text-ivory);
      text-decoration: none;
      font-family: var(--font-sans);
      font-weight: 500;
      font-size: 0.9rem;
      letter-spacing: 0.08em;
      padding: 0.5rem 0;
      transition: color 0.2s;
      opacity: 0.8;
    }
    .nav-item i {
      font-size: 1.4rem;
      width: 24px;
      text-align: center;
      color: var(--accent-gold);
    }
    .nav-item span {
      opacity: 0;
      transition: opacity 0.2s;
    }
    .app-sidebar:hover .nav-item span {
      opacity: 1;
    }
    .nav-item:hover, .nav-item.active {
      color: var(--accent-gold);
      opacity: 1;
    }
    .sidebar-bottom {
      width: 100%;
      padding: 0 1rem;
      display: flex;
      justify-content: center;
    }
    .lang-switch {
      color: var(--text-ivory);
      font-family: var(--font-sans);
      font-size: 0.8rem;
      opacity: 0.6;
    }
    /* 主内容区 */
    .main-content {
      margin-left: 80px;
      width: calc(100% - 80px);
      transition: margin-left 0.3s;
    }
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background-color: rgba(11, 12, 16, 0.95);
      backdrop-filter: blur(20px);
      z-index: 999;
      padding: 1rem 1.5rem;
      justify-content: space-between;
      align-items: center;
      border-bottom: 1px solid var(--border-gold-dim);
    }
    .hamburger {
      font-size: 1.8rem;
      color: var(--accent-gold);
      background: none;
      border: none;
    }
    .mobile-logo {
      font-family: var(--font-display);
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--accent-gold);
    }
    .mobile-drawer {
      position: fixed;
      top: 0;
      left: -100%;
      width: 80%;
      max-width: 320px;
      height: 100vh;
      background-color: var(--primary-black);
      backdrop-filter: blur(30px);
      z-index: 1001;
      padding: 2rem;
      display: flex;
      flex-direction: column;
      gap: 2rem;
      transition: left 0.3s ease;
      border-right: 1px solid var(--border-gold-dim);
    }
    .mobile-drawer.open {
      left: 0;
    }
    .drawer-close {
      align-self: flex-end;
      background: none;
      border: none;
      color: var(--accent-gold);
      font-size: 2rem;
    }
    /* 容器 */
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
    }
    section {
      padding: 8rem 0;
    }
    h2 {
      font-size: clamp(2rem, 5vw, 3.5rem);
      font-weight: 600;
      color: var(--text-ivory);
      border-left: 4px solid var(--accent-gold);
      padding-left: 1.5rem;
      margin-bottom: 3rem;
      font-family: var(--font-serif);
    }
    h3 {
      font-size: 1.5rem;
      font-weight: 600;
      color: var(--accent-gold);
      font-family: var(--font-serif);
    }
    .btn {
      display: inline-block;
      padding: 0.9rem 2.2rem;
      font-family: var(--font-sans);
      font-weight: 500;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      text-decoration: none;
      transition: all 0.3s ease;
      border-radius: var(--radius-geo);
      cursor: pointer;
    }
    .btn-primary {
      background: transparent;
      border: 2px solid var(--accent-gold);
      color: var(--accent-gold);
    }
    .btn-primary:hover {
      background: var(--accent-gold);
      color: var(--primary-black);
    }
    .btn-secondary {
      color: var(--text-ivory);
      border-bottom: 1px dotted rgba(197, 160, 89, 0.5);
      padding: 0.5rem 0;
    }
    .btn-secondary:hover {
      color: var(--accent-gold);
      border-bottom-style: solid;
    }
    /* Hero */
    #hero {
      height: 100vh;
      display: flex;
      align-items: center;
      background-color: var(--primary-black);
      background-image: radial-gradient(circle at 20% 30%, rgba(197,160,89,0.05) 0%, transparent 30%);
      position: relative;
    }
    .hero-content {
      max-width: 700px;
    }
    h1 {
      font-size: clamp(3rem, 8vw, 5.5rem);
      font-weight: 700;
      letter-spacing: 0.05em;
      color: var(--accent-gold);
      font-family: var(--font-serif);
      line-height: 1.2;
    }
    .hero-sub {
      font-family: var(--font-display);
      font-size: 1.8rem;
      color: var(--text-ivory);
      opacity: 0.7;
      margin: 0.5rem 0 1.5rem;
    }
    .hero-desc {
      font-size: 1.25rem;
      max-width: 600px;
      margin-bottom: 2.5rem;
      opacity: 0.85;
    }
    /* 核心优势 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-display);
      font-size: 4rem;
      font-weight: 700;
      color: var(--accent-gold);
    }
    /* 尊享服务交错 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 4rem;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 1;
      background-color: var(--bg-carbon);
      min-height: 300px;
      border-radius: var(--radius-geo);
      border: 1px solid var(--border-gold-dim);
      background-size: cover;
      background-position: center;
    }
    .service-text {
      flex: 1;
    }
    .gold-line {
      width: 60px;
      height: 2px;
      background: var(--accent-gold);
      margin: 1.5rem 0;
    }
    /* 时间线 */
    .timeline {
      display: flex;
      justify-content: space-between;
      position: relative;
    }
    .timeline::before {
      content: '';
      position: absolute;
      top: 40px;
      left: 5%;
      width: 90%;
      height: 1px;
      background: var(--border-gold-dim);
    }
    .milestone {
      text-align: center;
      z-index: 2;
    }
    /* 流程 */
    .process-steps {
      display: flex;
      justify-content: space-between;
    }
    .step {
      text-align: center;
      flex: 1;
    }
    /* 横向滚动案例 */
    .showcase-scroll {
      display: flex;
      gap: 2rem;
      overflow-x: auto;
      padding-bottom: 1rem;
      scrollbar-width: thin;
    }
    .showcase-card {
      min-width: 320px;
      background: var(--bg-carbon);
      border: 1px solid var(--border-gold-dim);
      border-radius: var(--radius-geo);
      transition: var(--transition-smooth);
    }
    .showcase-card:hover {
      border-color: var(--accent-gold);
      transform: translateY(-4px);
    }
    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1.5rem;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-gold-dim);
      padding: 1rem 0;
    }
    .faq-question {
      font-family: var(--font-sans);
      font-weight: 500;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      opacity: 0.8;
    }
    /* CTA */
    .cta-dark {
      background-color: var(--primary-black);
      text-align: center;
    }
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    @media (max-width: 1024px) {
      .app-sidebar { display: none; }
      .main-content { margin-left: 0; width: 100%; }
      .mobile-header { display: flex; }
      section { padding: 5rem 0; }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .service-row, .service-row.reverse { flex-direction: column; }
      .timeline { flex-wrap: wrap; gap: 2rem; }
      .process-steps { flex-wrap: wrap; }
      .faq-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }