/* roulang page: index */
/* ----- 设计变量与重置 ----- */
    :root {
      --primary: #7B2FBE;
      --primary-glow: #9B4DCA;
      --secondary: #00E5A0;
      --deep-bg: #1E1E24;
      --darker-bg: #12121A;
      --card-bg: rgba(30, 30, 36, 0.8);
      --text-primary: #F0F0FA;
      --text-secondary: #B0B0C8;
      --border-dim: rgba(123, 47, 190, 0.25);
      --border-glow: rgba(123, 47, 190, 0.5);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-card: 0 4px 20px rgba(123, 47, 190, 0.15);
      --shadow-hover: 0 12px 28px rgba(123, 47, 190, 0.35);
      --space-section: 80px;
      --max-width: 1280px;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      transition: all 0.2s ease;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      background: var(--darker-bg);
      font-family: var(--font-title);
      color: var(--text-primary);
      line-height: 1.75;
      font-size: 15px;
      background: radial-gradient(circle at 20% 10%, #1E1E24 0%, #0B0B10 100%);
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 背景动态线条待用到hero生物 */
    .section {
      padding: var(--space-section) 0;
      position: relative;
    }

    h2 {
      font-size: 2.2rem;
      font-weight: 800;
      letter-spacing: -0.5px;
      margin-bottom: 1.2rem;
      color: white;
    }

    h3 {
      font-size: 1.4rem;
      font-weight: 700;
      letter-spacing: -0.3px;
    }

    /* ----- 导航组件 (沉浸式透明) ----- */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(18, 18, 22, 0.88);
      backdrop-filter: blur(14px);
      border-bottom: 1px solid var(--border-glow);
      z-index: 100;
      height: 70px;
      transition: all 0.25s;
    }

    .nav-container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }

    .logo-area {
      display: flex;
      flex-direction: column;
      align-items: flex-start;
    }
    .logo-main {
      font-size: 1.5rem;
      font-weight: 800;
      letter-spacing: 1px;
      color: white;
      line-height: 1.2;
      background: linear-gradient(135deg, #fff 0%, #e0d9ff 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .logo-sub {
      font-size: 0.7rem;
      font-weight: 500;
      color: var(--secondary);
      letter-spacing: 0.5px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      color: var(--text-secondary);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 8px 0;
      transition: 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--secondary);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--secondary);
      transition: width 0.25s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 1.6rem;
    }

    /* 按钮复用 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      text-decoration: none;
      cursor: pointer;
      border: 1px solid transparent;
      transition: all 0.3s ease;
      font-size: 1rem;
      letter-spacing: 0.3px;
    }
    .btn-primary {
      background: linear-gradient(145deg, #7B2FBE, #5F27CD);
      color: white;
      border: 1px solid rgba(255,255,255,0.1);
      box-shadow: 0 6px 18px rgba(123,47,190,0.3);
    }
    .btn-primary:hover {
      box-shadow: 0 0 25px rgba(123,47,190,0.7);
      transform: translateY(-2px);
    }
    .btn-outline {
      border: 1.5px solid var(--secondary);
      color: var(--secondary);
      background: transparent;
    }
    .btn-outline:hover {
      background: var(--secondary);
      color: #0B0B10;
      border-color: var(--secondary);
    }

    /* ----- 英雄区域 ----- */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      background-color: #0a0a12;
    }
    .hero .container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      align-items: center;
      gap: 3rem;
      position: relative;
      z-index: 3;
      margin-top: 30px;
    }
    .hero-text h1 {
      font-size: 3.6rem;
      font-weight: 900;
      line-height: 1.2;
      background: linear-gradient(to right, #fff, var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 1.5rem;
    }
    .hero-text .sub {
      font-size: 1.2rem;
      color: #A0A0C0;
      margin-bottom: 2rem;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-visual {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      height: 400px;
      width: 100%;
      position: relative;
      box-shadow: 0 20px 40px rgba(123,47,190,0.3);
      border: 1px solid rgba(123,47,190,0.4);
      backdrop-filter: blur(2px);
    }
    .hero-visual::after {
      content: "";
      position: absolute;
      top: 0; left: 0; right: 0; bottom: 0;
      background: radial-gradient(circle at 30% 30%, rgba(123,47,190,0.3), transparent 70%);
      border-radius: 24px;
    }

    /* 非对称卡片区域 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 1fr 1.2fr 1fr;
      gap: 28px;
      margin-top: 3rem;
      align-items: start;
    }
    .advantage-card {
      background: var(--card-bg);
      backdrop-filter: blur(10px);
      border-radius: var(--radius-card);
      border: 1px solid var(--border-dim);
      padding: 1.8rem 1.5rem;
      transition: all 0.25s;
      color: var(--text-secondary);
    }
    .advantage-card.featured {
      border-color: var(--secondary);
      box-shadow: 0 0 24px rgba(0,229,160,0.2);
      background: rgba(0,229,160,0.04);
    }
    .advantage-card:hover {
      border-color: var(--secondary);
      box-shadow: var(--shadow-hover);
      transform: translateY(-5px);
    }
    .advantage-icon {
      font-size: 2rem;
      color: var(--secondary);
      margin-bottom: 1rem;
    }

    /* 左文右图矩阵 */
    .feature-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 64px;
      align-items: center;
      margin: 5rem 0;
    }
    .feature-image img {
      width: 100%;
      border-radius: 20px;
      border: 1px solid var(--border-dim);
    }
    .feature-text p {
      color: var(--text-secondary);
    }

    .badge {
      background: #7B2FBE20;
      color: #bb86fc;
      padding: 4px 12px;
      border-radius: 16px;
      font-size: 0.8rem;
      display: inline-block;
      margin-bottom: 10px;
    }

    /* 数据看板 */
    .stats-board {
      display: flex;
      gap: 48px;
      background: rgba(0,0,0,0.4);
      border: 1px solid #7B2FBE40;
      border-radius: 24px;
      padding: 32px;
      margin: 40px 0;
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: white;
      line-height: 1;
    }
    .logo-wall {
      display: flex;
      flex-wrap: wrap;
      gap: 24px;
      align-items: center;
      margin-top: 24px;
    }

    /* FAQ 手风琴 */
    .faq-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 20px;
      margin-top: 2.5rem;
    }
    .faq-item {
      background: var(--card-bg);
      border: 1px solid var(--border-dim);
      border-radius: var(--radius-card);
      padding: 1.2rem 1.5rem;
    }
    .faq-question {
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: white;
    }

    /* 页脚 */
    .footer {
      background: #0b0b12;
      padding: 3rem 0 1.5rem;
      border-top: 1px solid var(--border-dim);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 24px;
    }

    @media (max-width: 1024px) {
      .advantages-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .hero .container, .feature-row { grid-template-columns: 1fr; }
      .faq-grid { grid-template-columns: 1fr; }
      .nav-links { display: none; }
      .mobile-menu-toggle { display: block; }
    }