/* roulang page: index */
:root {
      --bg-deep: #0B0E14;
      --gold: #F0A500;
      --gold-dark: #E08900;
      --purple: #7B4BFF;
      --surface: rgba(20, 25, 40, 0.7);
      --border-light: rgba(255, 255, 255, 0.06);
      --border-glow: rgba(123, 75, 255, 0.08);
      --text-primary: #E8ECF1;
      --text-secondary: #8A94A6;
      --text-ondark: #0B0E14;
      --radius-card: 20px;
      --radius-btn: 12px;
      --shadow-card: 0 18px 40px -12px rgba(0,0,0,0.6), 0 0 0 1px rgba(255,255,255,0.05);
      --shadow-hover: 0 24px 48px -12px rgba(0,0,0,0.8), 0 0 0 1px rgba(240,165,0,0.25);
      --transition-bounce: 0.25s cubic-bezier(0.2, 0.9, 0.4, 1);
    }

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

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', system-ui, -apple-system, 'Segoe UI', sans-serif;
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 28px;
    }

    /* 导航 */
    .nav-bar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(11, 14, 20, 0.82);
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      border-bottom: 1px solid rgba(240, 165, 0, 0.1);
      transition: background 0.3s;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 750;
      font-size: 1.6rem;
      letter-spacing: 1px;
      color: #fff;
      text-decoration: none;
    }
    .logo-icon {
      font-size: 2.1rem;
      color: var(--gold);
      filter: drop-shadow(0 0 8px rgba(240,165,0,0.7));
    }
    .logo-text {
      background: linear-gradient(135deg, #fff 0%, #E0E4F0 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .nav-links {
      display: flex;
      gap: 2.8rem;
      align-items: center;
      font-weight: 500;
    }
    .nav-links a {
      color: var(--text-secondary);
      text-decoration: none;
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
      font-size: 0.95rem;
      letter-spacing: 0.4px;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--gold);
      border-bottom-color: var(--gold);
    }

    .burger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .burger span {
      width: 26px;
      height: 2.5px;
      background: var(--text-primary);
      border-radius: 4px;
      transition: 0.2s;
    }

    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(8, 10, 18, 0.96);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 36px 28px;
        gap: 26px;
        transform: translateY(-120%);
        transition: transform 0.3s ease;
        border-bottom: 1px solid var(--border-light);
      }
      .nav-links.open {
        transform: translateY(0);
      }
      .burger {
        display: flex;
      }
      .container {
        padding: 0 20px;
      }
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      background: radial-gradient(circle at 30% 40%, #1f1b3a 0%, #0B0E14 75%);
      margin-bottom: 60px;
    }
    .hero-bg {
      position: absolute;
      inset: 0;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center 30%;
      opacity: 0.25;
      mix-blend-mode: soft-light;
    }
    .hero-content {
      position: relative;
      z-index: 5;
      max-width: 750px;
      padding: 140px 0 80px;
    }
    .hero h1 {
      font-size: clamp(2.8rem, 8vw, 4.8rem);
      font-weight: 800;
      line-height: 1.15;
      text-shadow: 0 4px 28px rgba(0,0,0,0.6);
    }
    .highlight {
      color: var(--gold);
      text-shadow: 0 0 28px rgba(240,165,0,0.5);
    }
    .hero p {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin: 24px 0 36px;
      max-width: 580px;
    }
    .btn-group {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: linear-gradient(135deg, #F0A500 0%, #E08900 100%);
      border: none;
      padding: 15px 42px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      font-size: 1.05rem;
      color: var(--text-ondark);
      letter-spacing: 0.8px;
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      box-shadow: 0 8px 24px rgba(240,165,0,0.35);
      transition: all var(--transition-bounce);
      cursor: pointer;
    }
    .btn-primary:hover {
      box-shadow: 0 0 36px rgba(240,165,0,0.65);
      transform: scale(1.03);
      background: linear-gradient(135deg, #FFB31A 0%, #F0A500 100%);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--purple);
      color: #CBB5FF;
      padding: 15px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: all 0.25s;
    }
    .btn-outline:hover {
      background: rgba(123,75,255,0.1);
      border-color: #a78bfa;
      box-shadow: 0 0 22px rgba(123,75,255,0.4);
    }

    section {
      padding: 90px 0;
    }

    .section-title {
      font-size: 2.3rem;
      font-weight: 700;
      margin-bottom: 18px;
      display: flex;
      align-items: center;
      gap: 14px;
    }
    .title-bar {
      width: 6px;
      height: 36px;
      background: var(--gold);
      border-radius: 4px;
    }

    /* 核心优势 — 非三列等距，错位卡片 */
    .advantages-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 28px;
      margin-top: 48px;
      justify-content: center;
    }
    .adv-card {
      background: var(--surface);
      backdrop-filter: blur(20px);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 32px 28px;
      flex: 1 1 260px;
      max-width: 340px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s;
      position: relative;
      border-left: 5px solid var(--gold);
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .adv-card:nth-child(2) {
      margin-top: 25px;
      border-left-color: var(--purple);
    }
    .adv-card:nth-child(3) {
      margin-top: -10px;
      border-left-color: var(--gold);
    }
    .adv-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
      border-left-width: 6px;
    }
    .adv-icon {
      font-size: 2.4rem;
      color: var(--gold);
    }
    .adv-card h3 {
      font-size: 1.4rem;
    }

    /* 功能分组 左右交替图文 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin: 80px 0;
      flex-wrap: wrap;
    }
    .feature-row.reverse {
      flex-direction: row-reverse;
    }
    .feature-text {
      flex: 1 1 400px;
    }
    .feature-img {
      flex: 1 1 400px;
      background: rgba(25, 30, 45, 0.5);
      border-radius: 28px;
      overflow: hidden;
      backdrop-filter: blur(10px);
    }
    .feature-img img {
      width: 100%;
      height: auto;
      display: block;
    }
    .feature-list {
      list-style: none;
      margin-top: 24px;
    }
    .feature-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 14px;
      color: var(--text-secondary);
    }
    .feature-list li::before {
      content: "●";
      color: var(--gold);
      font-size: 1.2rem;
    }

    /* 使用场景卡片 */
    .scenarios {
      display: flex;
      gap: 30px;
      flex-wrap: wrap;
      margin-top: 40px;
    }
    .scene-card {
      flex: 1 1 250px;
      background: var(--surface);
      backdrop-filter: blur(16px);
      border-radius: 24px;
      padding: 32px 24px;
      border: 1px solid var(--border-light);
      transition: all 0.3s;
    }
    .scene-card:nth-child(1) { border-top: 4px solid var(--gold); }
    .scene-card:nth-child(2) { border-top: 4px solid var(--purple); }
    .scene-card:nth-child(3) { border-top: 4px solid #3a4b6b; }
    .scene-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }

    /* 数据区 */
    .stats {
      display: flex;
      justify-content: center;
      gap: 70px;
      flex-wrap: wrap;
      margin: 48px 0 20px;
      background: rgba(18, 22, 32, 0.6);
      padding: 44px 28px;
      border-radius: 36px;
    }
    .stat-item {
      text-align: center;
    }
    .stat-num {
      font-size: 3.2rem;
      font-weight: 800;
      color: var(--gold);
      letter-spacing: 1px;
      font-feature-settings: "tnum";
    }
    .stat-label {
      color: var(--text-secondary);
      text-transform: uppercase;
      letter-spacing: 2px;
      margin-top: 8px;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 8px;
    }
    .faq-question {
      background: transparent;
      width: 100%;
      text-align: left;
      padding: 22px 8px;
      font-weight: 700;
      font-size: 1.1rem;
      color: #fff;
      border: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      transition: 0.2s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
      padding: 0 8px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding-bottom: 18px;
    }

    .cta-section {
      background: radial-gradient(circle at 50% 30%, #2b1f4a, #0B0E14);
      text-align: center;
      padding: 90px 28px;
      border-radius: 48px;
    }
    .footer {
      border-top: 1px solid var(--gold);
      padding: 40px 0;
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      color: var(--text-secondary);
    }

    @media (max-width: 768px) {
      .hero h1 { font-size: 2.5rem; }
      .feature-row, .feature-row.reverse { flex-direction: column; }
      .stats { gap: 40px; }
    }