/* roulang page: index */
/* ----- 设计变量 & 基础重置 ----- */
    :root {
      --deep-green: #0A1C1A;
      --midnight-black: #0B0E11;
      --champagne-gold: #D4AF37;
      --competition-red: #C8102E;
      --pure-white: #FFFFFF;
      --off-white: #F4F4F6;
      --gray-text: #B0B8B5;
      --dark-card-bg: rgba(10, 28, 26, 0.65);
      --glass-border: rgba(212, 175, 55, 0.25);
      --glass-bg: rgba(255, 255, 255, 0.03);
      
      --font-heading: 'Noto Sans SC', 'Oswald', sans-serif;
      --font-body: 'Inter', 'Noto Sans SC', sans-serif;
      
      --radius-sm: 4px;
      --radius-card: 8px;
      --shadow-gold: 0 12px 28px rgba(212, 175, 55, 0.18);
      --shadow-dark: 0 20px 40px rgba(0, 0, 0, 0.5);
      
      --transition: all 0.3s ease;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    html {
      scroll-behavior: smooth;
    }
    
    body {
      font-family: var(--font-body);
      background-color: var(--deep-green);
      color: var(--off-white);
      line-height: 1.7;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
      background-image: radial-gradient(circle at 25% 0%, rgba(212,175,55,0.08) 0%, transparent 45%);
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    
    button, .btn {
      cursor: pointer;
      font-family: var(--font-heading);
      font-weight: 600;
      letter-spacing: 1px;
      border: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition);
      border-radius: var(--radius-sm);
      text-transform: uppercase;
      font-size: 0.95rem;
      padding: 14px 34px;
      position: relative;
      overflow: hidden;
      clip-path: polygon(4px 0, 100% 0, calc(100% - 4px) 100%, 0 100%);
    }
    
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 28px;
    }
    
    /* 装饰元素 */
    .section-badge {
      display: inline-block;
      color: var(--champagne-gold);
      font-size: 0.9rem;
      font-weight: 600;
      letter-spacing: 2px;
      text-transform: uppercase;
      border: 1px solid var(--champagne-gold);
      padding: 4px 14px;
      border-radius: 20px;
      margin-bottom: 16px;
      background: rgba(212,175,55,0.05);
    }
    
    /* ----- 导航 (#header-nav) ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 28, 26, 0.88);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(212, 175, 55, 0.2);
      transition: background 0.3s;
    }
    
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 76px;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-family: var(--font-heading);
      font-weight: 900;
      font-size: 1.9rem;
      letter-spacing: 3px;
      color: var(--pure-white);
    }
    
    .logo-icon {
      font-size: 2.2rem;
      color: var(--champagne-gold);
      filter: drop-shadow(0 0 6px rgba(212,175,55,0.5));
    }
    
    .nav-links {
      display: flex;
      align-items: center;
      gap: 38px;
    }
    
    .nav-links a {
      font-weight: 500;
      font-size: 0.95rem;
      letter-spacing: 0.8px;
      color: var(--off-white);
      position: relative;
      padding: 6px 0;
      transition: color 0.25s;
    }
    
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--champagne-gold);
      transition: width 0.3s ease;
    }
    
    .nav-links a:hover {
      color: var(--champagne-gold);
    }
    
    .nav-links a:hover::after {
      width: 100%;
    }
    
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      color: var(--champagne-gold);
      font-size: 1.9rem;
      cursor: pointer;
    }
    
    /* 移动端菜单 */
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        height: 100vh;
        background: rgba(10, 28, 26, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        gap: 32px;
        transition: right 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        border-left: 1px solid var(--champagne-gold);
        padding: 50px;
      }
      .nav-links.active {
        right: 0;
      }
      .menu-toggle {
        display: block;
      }
    }
    
    /* ----- 英雄首屏 (#hero) ----- */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(10,28,26,0.82) 0%, rgba(11,14,17,0.78) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-blend-mode: overlay;
      position: relative;
      padding-top: 80px;
    }
    
    .hero-content {
      max-width: 820px;
      margin: 0 auto;
      text-align: center;
    }
    
    .hero h1 {
      font-family: var(--font-heading);
      font-weight: 900;
      font-size: clamp(3.2rem, 7vw, 5.2rem);
      line-height: 1.15;
      color: var(--off-white);
      margin-bottom: 24px;
      text-shadow: 0 4px 20px rgba(0,0,0,0.6);
    }
    
    .hero .highlight {
      color: var(--champagne-gold);
      position: relative;
    }
    
    .hero p {
      font-size: 1.2rem;
      color: #d0d6d4;
      margin-bottom: 40px;
      max-width: 600px;
      margin-left: auto;
      margin-right: auto;
    }
    
    .btn-primary {
      background: var(--champagne-gold);
      color: var(--deep-green);
      font-weight: 700;
      box-shadow: 0 8px 22px rgba(212,175,55,0.3);
    }
    .btn-primary:hover {
      background: #e4bf4a;
      box-shadow: 0 12px 28px rgba(212,175,55,0.5);
      transform: translateY(-2px);
    }
    
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--champagne-gold);
      color: var(--champagne-gold);
      margin-left: 18px;
    }
    .btn-outline:hover {
      background: rgba(212,175,55,0.1);
      border-color: #fff;
      color: #fff;
    }
    
    /* ----- 核心优势 (#advantages) 非对称卡片 ----- */
    .section {
      padding: 100px 0;
      position: relative;
    }
    
    .advantages-grid {
      display: grid;
      grid-template-columns: 1.25fr 0.9fr 1.1fr;
      gap: 30px;
      margin-top: 48px;
    }
    
    .adv-card {
      background: var(--glass-bg);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      padding: 44px 32px;
      backdrop-filter: blur(8px);
      transition: transform 0.35s, box-shadow 0.35s, border-color 0.3s;
    }
    
    .adv-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-gold);
      border-color: var(--champagne-gold);
    }
    
    .adv-icon {
      font-size: 2.4rem;
      color: var(--champagne-gold);
      margin-bottom: 24px;
    }
    
    .adv-card h3 {
      font-family: var(--font-heading);
      font-size: 1.8rem;
      font-weight: 700;
      margin-bottom: 14px;
    }
    
    @media (max-width: 992px) {
      .advantages-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 640px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* ----- 功能分组 (#features) Z型动线 ----- */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 100px;
    }
    .feature-row.reverse {
      flex-direction: row-reverse;
    }
    .feature-text {
      flex: 1;
    }
    .feature-image {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid rgba(212,175,55,0.2);
    }
    .feature-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    
    @media (max-width: 768px) {
      .feature-row, .feature-row.reverse {
        flex-direction: column;
        gap: 30px;
      }
    }
    
    /* 场景画廊 */
    .scenario-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .scenario-card {
      position: relative;
      border-radius: var(--radius-card);
      overflow: hidden;
      background: var(--dark-card-bg);
      border: 1px solid var(--glass-border);
    }
    .scenario-card img {
      width: 100%;
      height: 260px;
      object-fit: cover;
    }
    @media (max-width: 768px) {
      .scenario-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* 案例深色区 */
    .dark-bg {
      background: var(--midnight-black);
      background-image: radial-gradient(circle at 50% 20%, #1e2b29 0%, #0b0e11 80%);
    }
    
    .stats {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 30px;
    }
    .stat-item h4 {
      font-size: 3rem;
      font-weight: 900;
      color: var(--champagne-gold);
    }
    
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 22px 0;
      cursor: pointer;
      transition: 0.2s;
    }
    .faq-item:hover {
      border-left: 3px solid var(--champagne-gold);
      padding-left: 18px;
    }
    
    /* CTA 行动号召 */
    .cta-section {
      background: linear-gradient(0deg, #0a1c1a 0%, #0f2420 100%);
      text-align: center;
    }
    
    /* Footer */
    .footer {
      background: #050a09;
      padding: 60px 0 30px;
      text-align: center;
      color: #9aa3a1;
    }
    
    @media (max-width: 520px) {
      .btn-outline { margin-left: 0; margin-top: 14px; }
    }