/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary-purple: #7B2FF7;
      --neon-purple: #A855F7;
      --accent-gold: #F5A623;
      --bg-deep-black: #0A0A0F;
      --bg-dark-purple: #12081F;
      --cyan-glow: #00F0FF;
      --success-green: #00E676;
      --danger-red: #FF1744;
      --text-light: #F2F0F5;
      --text-muted: #B0ADC4;
      --text-disabled: #6B6880;
      --card-radius-lg: 24px;
      --card-radius-md: 16px;
      --card-radius-sm: 12px;
      --shadow-card: 0 4px 24px rgba(123,47,247,0.15);
      --shadow-card-hover: 0 8px 40px rgba(123,47,247,0.3), 0 0 20px rgba(0,240,255,0.2);
      --border-card: 1px solid rgba(168,85,247,0.2);
      --border-hover: 1px solid rgba(0,240,255,0.5);
      --font-head-cn: 'PingFang SC','Microsoft YaHei','Heiti SC',sans-serif;
      --font-number: 'Inter','SF Pro Display',sans-serif;
      --transition-smooth: 0.3s ease-out;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--bg-deep-black);
    }
    body {
      font-family: 'PingFang SC','Microsoft YaHei','Heiti SC',sans-serif;
      background-color: var(--bg-deep-black);
      color: var(--text-light);
      line-height: 1.7;
      font-weight: 400;
      overflow-x: hidden;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }
    /* 背景噪点纹理 */
    body::before {
      content: "";
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(/%23noiseFilter)' opacity='0.03'/%3E%3C/svg%3E");
      pointer-events: none;
      z-index: 0;
    }
    .main-wrapper {
      display: flex;
      flex: 1;
      position: relative;
      z-index: 1;
    }
    /* ----- 左侧竖向导航 (桌面端) ----- */
    .side-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: 220px;
      height: 100vh;
      background-color: #0A0A0F;
      display: flex;
      flex-direction: column;
      padding: 2rem 1rem;
      z-index: 100;
      border-right: 1px solid transparent;
      background-image: linear-gradient(to bottom, transparent, rgba(123,47,247,0.3), transparent);
      background-position: right;
      background-size: 1px 100%;
      background-repeat: no-repeat;
    }
    .logo-area {
      margin-bottom: 2.5rem;
      padding-left: 0.5rem;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-size: 1.6rem;
      font-weight: 900;
      color: white;
      letter-spacing: -0.02em;
      font-family: var(--font-head-cn);
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--cyan-glow);
      filter: drop-shadow(0 0 6px #00F0FF);
    }
    .domain-text {
      font-size: 0.75rem;
      color: #6B6880;
      margin-top: 0.2rem;
      padding-left: 0.2rem;
    }
    .nav-links {
      display: flex;
      flex-direction: column;
      gap: 0.6rem;
      flex: 1;
    }
    .nav-item {
      height: 48px;
      display: flex;
      align-items: center;
      padding-left: 1rem;
      border-left: 3px solid transparent;
      color: #B0ADC4;
      font-weight: 500;
      text-decoration: none;
      transition: all 0.2s ease;
      border-radius: 0 8px 8px 0;
      background: transparent;
    }
    .nav-item:hover {
      color: #FFFFFF;
      border-left-color: rgba(123,47,247,0.5);
      background: rgba(123,47,247,0.1);
    }
    .nav-item.active {
      border-left-color: var(--cyan-glow);
      color: white;
      background: rgba(123,47,247,0.2);
      box-shadow: 0 0 12px rgba(0,240,255,0.3);
    }
    .nav-cta {
      margin-top: auto;
      background: linear-gradient(135deg, #F5A623, #FF8C00);
      color: white;
      font-weight: 700;
      text-align: center;
      padding: 14px;
      border-radius: 12px;
      text-decoration: none;
      letter-spacing: 0.5px;
      transition: 0.25s ease;
      box-shadow: 0 4px 12px rgba(245,166,35,0.4);
    }
    .nav-cta:hover {
      transform: scale(1.03);
      box-shadow: 0 0 24px rgba(245,166,35,0.7);
    }
    /* 右侧内容区 */
    .content-area {
      margin-left: 220px;
      width: calc(100% - 220px);
      max-width: 1280px;
      padding: 0 2rem;
    }
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: #0A0A0F;
      z-index: 110;
      align-items: center;
      justify-content: space-between;
      padding: 0 1.5rem;
      border-bottom: 1px solid rgba(123,47,247,0.3);
    }
    #menu-toggle {
      display: none;
    }
    .hamburger {
      font-size: 1.8rem;
      color: white;
      cursor: pointer;
    }
    /* 通用区块 */
    section {
      padding: 100px 0 80px;
      position: relative;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 900;
      color: white;
      margin-bottom: 2rem;
      letter-spacing: -0.02em;
      display: flex;
      align-items: center;
      gap: 1rem;
    }
    .title-underline {
      width: 60px;
      height: 3px;
      background: var(--primary-purple);
      display: inline-block;
    }
    .container {
      max-width: 1060px;
      margin: 0 auto;
    }
    /* 卡片基础 */
    .card {
      background: #12081F;
      border-radius: 24px;
      padding: 2rem;
      border: 1px solid rgba(168,85,247,0.25);
      box-shadow: 0 4px 24px rgba(123,47,247,0.15);
      transition: all 0.3s ease;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: 0 8px 40px rgba(123,47,247,0.35), 0 0 20px rgba(0,240,255,0.2);
      border-color: rgba(0,240,255,0.5);
    }
    .btn-gold {
      background: linear-gradient(135deg, #F5A623, #FF8C00);
      border: none;
      color: white;
      font-weight: 700;
      padding: 16px 36px;
      border-radius: 12px;
      font-size: 1rem;
      cursor: pointer;
      transition: 0.2s;
      text-decoration: none;
      display: inline-block;
      box-shadow: 0 4px 14px rgba(245,166,35,0.4);
    }
    .btn-gold:hover {
      transform: scale(1.05);
      box-shadow: 0 0 30px rgba(245,166,35,0.7);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid #7B2FF7;
      color: #A855F7;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: 12px;
      transition: 0.2s;
      text-decoration: none;
      display: inline-block;
    }
    .btn-outline:hover {
      background: rgba(123,47,247,0.15);
      border-color: #00F0FF;
      color: #00F0FF;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .side-nav {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .content-area {
        margin-left: 0;
        width: 100%;
        padding: 0 1.5rem;
        margin-top: 64px;
      }
      section {
        padding: 60px 0;
      }
    }
    @media (max-width: 768px) {
      .section-title {
        font-size: 2rem;
      }
    }