/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --deep-purple-black: #0B0C10;
      --surface-dark: #1a1c24;
      --card-bg: rgba(18, 20, 28, 0.55);
      --card-border: rgba(0, 245, 212, 0.25);
      --golden-acc: #E85D04;
      --cyan-glow: #00F5D4;
      --text-primary: #F0F0F5;
      --text-secondary: #C0C0D0;
      --text-muted: rgba(224, 224, 240, 0.7);
      --radius-xl: 24px;
      --radius-lg: 20px;
      --radius-md: 16px;
      --radius-sm: 8px;
      --shadow-card: 0 25px 45px -12px rgba(0,0,0,0.5);
      --shadow-glow: 0 0 25px rgba(232, 93, 4, 0.7);
      --transition: all 0.3s ease;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--deep-purple-black);
      font-size: 16px;
    }
    body {
      font-family: var(--font-sans);
      background: radial-gradient(ellipse at 40% 20%, #14162e 0%, #0B0C10 75%);
      color: var(--text-primary);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .container {
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      position: relative;
    }
    /* 通用组件预设 */
    .btn {
      display: inline-block;
      font-weight: 700;
      border: none;
      text-decoration: none;
      cursor: pointer;
      transition: var(--transition);
    }
    .primary-btn {
      background: linear-gradient(135deg, #E85D04 0%, #D00000 100%);
      color: #fff;
      padding: 14px 36px;
      border-radius: 50px;
      box-shadow: var(--shadow-glow);
      letter-spacing: 0.06em;
      border: 1px solid rgba(255,255,255,0.15);
    }
    .primary-btn:hover {
      box-shadow: 0 0 35px rgba(0, 245, 212, 0.7), 0 0 20px #E85D04;
      transform: scale(1.05);
      background: linear-gradient(135deg, #e2741c, #c51b1b);
    }
    .glass-btn {
      background: transparent;
      border: 1px solid var(--cyan-glow);
      color: var(--cyan-glow);
      padding: 12px 30px;
      border-radius: 50px;
      backdrop-filter: blur(6px);
      font-weight: 600;
    }
    .glass-btn:hover {
      background: rgba(0,245,212,0.08);
      box-shadow: 0 0 20px rgba(0,245,212,0.4);
    }
    /* 玻璃拟态卡片 */
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(18px) saturate(200%);
      -webkit-backdrop-filter: blur(18px) saturate(200%);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card), inset 0 0 0 1px rgba(255,255,4255,0.06);
      transition: var(--transition);
    }
    .glass-card:hover {
      border-color: rgba(0, 245, 212, 0.5);
      box-shadow: 0 2px 30px rgba(0, 245, 212, 0.25);
      transform: translateY(-6px);
    }
    h1, h2, h3 {
      font-weight: 700;
      letter-spacing: -0.5px;
    }
  
    /* ---------- 导航 ---------- */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(8, 8, 14, 0.78);
      backdrop-filter: blur(22px);
      -webkit-backdrop-filter: blur(22px);
      z-index: 100;
      border-bottom: 1px solid rgba(0, 245, 212, 0.22);
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      font-size: 30px;
      color: var(--golden-acc);
      filter: drop-shadow(0 0 8px #E85D04);
    }
    .logo-text {
      font-weight: 800;
      font-size: 1.6rem;
      background: linear-gradient(to right, #fff, #ddd);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: 1px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
      transition: var(--transition);
    }
    .nav-links a {
      color: #E0E0E0;
      text-decoration: none;
      font-weight: 500;
      position: relative;
      font-size: 1rem;
      letter-spacing: 0.3px;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--golden-acc);
      text-shadow: 0 0 12px #E85D04;
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -8px;
      left: 30%;
      width: 28%;
      height: 3px;
      background: var(--cyan-glow);
      border-radius: 4px;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      cursor: pointer;
      color: var(--cyan-glow);
    }
    .mobile-menu-wrapper {
      display: none;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
        font-size: 28px;
      }
      .mobile-menu-wrapper {
        display: block;
        position: fixed;
        inset: 0;
        background: rgba(6, 6, 12, 0.95);
        backdrop-filter: blur(30px);
        z-index: 99;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 40px;
        transform: translateX(100%);
        transition: 0.5s ease;
      }
      .mobile-menu-wrapper.open {
        transform: translateX(0);
        display: flex;
      }
      .mobile-menu-wrapper a {
        font-size: 2.3rem;
        color: white;
        font-weight: 700;
        text-decoration: none;
      }
    }
    /* Hero */
    .hero {
      padding: 130px 0 80px;
      display: flex;
      align-items: center;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero-left h1 {
      font-size: clamp(2.4rem, 5vw, 4rem);
      font-weight: 800;
      line-height: 1.15;
      margin-bottom: 20px;
      text-shadow: 0 0 18px rgba(232,93,4,0.5);
    }
    .highlight {
      color: var(--cyan-glow);
    }
    .hero-desc {
      font-size: 1.18rem;
      color: #ccc;
      margin-bottom: 30px;
    }
    .hero-visual {
      display: flex;
      justify-content: center;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: var(--radius-xl);
      min-height: 360px;
      position: relative;
      overflow: hidden;
      border: 1px solid rgba(0,245,212,0.2);
    }
    .hero-energy {
      backdrop-filter: blur(12px);
      background: rgba(10,12,18,0.45);
      width: 100%;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-xl);
    }
    .floating-glyph {
      font-size: 8rem;
      color: rgba(232,93,4,0.8);
      text-shadow: 0 0 60px #E85D04;
    }
    /* 通用section */
    section {
      padding: 90px 0;
      scroll-margin-top: 80px;
    }
    .section-title {
      font-size: 2.5rem;
      margin-bottom: 16px;
      font-weight: 700;
      text-align: center;
    }
    .section-sub {
      color: #aaa;
      text-align: center;
      margin-bottom: 50px;
    }