/* roulang page: index */
:root {
      --primary: #00E676;
      --primary-dark: #00C853;
      --accent: #FF6D00;
      --deep-bg: #0F0F1A;
      --panel-bg: #1A1A2E;
      --white: #FFFFFF;
      --gray-50: #F5F6FA;
      --gray-100: #F0F2F5;
      --gray-200: #E2E6ED;
      --gray-400: #96A0B0;
      --gray-600: #546278;
      --gray-800: #2A2E3A;
      --text-main: #1E2229;
      --text-soft: #606870;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.06);
      --shadow-lg: 0 16px 40px rgba(0,0,0,0.1);
      --shadow-glow: 0 0 24px rgba(0,230,118,0.25);
      --radius-sm: 8px;
      --radius: 12px;
      --radius-lg: 20px;
      --font-mono: 'SF Mono', 'Menlo', 'Cascadia Code', monospace;
      --transition: 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      line-height: 1.6;
      color: var(--text-main);
      background-color: var(--gray-50);
      -webkit-font-smoothing: antialiased;
    }
    a, button, input {
      font-family: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 20px;
      }
    }
    /* 导航 base */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: transparent;
      transition: background 0.3s, box-shadow 0.3s;
    }
    .header.scrolled {
      background: var(--panel-bg);
      box-shadow: 0 4px 20px rgba(0,0,0,0.35);
      border-bottom: 1px solid var(--primary);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      color: var(--white);
      font-weight: 700;
      font-size: 1.6rem;
      letter-spacing: 0.5px;
      text-decoration: none;
    }
    .logo i {
      color: var(--primary);
      font-size: 2rem;
      filter: drop-shadow(0 0 8px rgba(0,230,118,0.5));
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      text-decoration: none;
      color: rgba(255,255,255,0.82);
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .mobile-toggle {
      display: none;
      background: transparent;
      border: none;
      color: white;
      font-size: 1.6rem;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .mobile-toggle {
        display: block;
      }
      .header .nav-links {
        display: none;
      }
    }
    /* 底部移动优先导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 68px;
      background: var(--panel-bg);
      border-top: 1px solid rgba(255,255,255,0.08);
      backdrop-filter: blur(10px);
      z-index: 999;
      justify-content: space-around;
      align-items: center;
      padding: 0 8px;
    }
    @media (max-width: 768px) {
      .mobile-bottom-nav {
        display: flex;
      }
      body {
        padding-bottom: 80px;
      }
      .header {
        background: var(--panel-bg);
        border-bottom: 1px solid rgba(255,255,255,0.08);
      }
      .nav-links.mobile-open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #1A1A2E;
        padding: 24px;
        gap: 24px;
      }
    }
    .mobile-nav-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      color: #aaa;
      text-decoration: none;
      font-size: 0.7rem;
      font-weight: 500;
      transition: 0.2s;
    }
    .mobile-nav-item i {
      font-size: 1.3rem;
      margin-bottom: 2px;
    }
    .mobile-nav-item.active {
      color: var(--primary);
    }
    .mobile-cta {
      background: var(--primary);
      color: #0F0F1A;
      width: 52px;
      height: 52px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      margin-top: -18px;
      box-shadow: 0 4px 18px rgba(0,230,118,0.5);
    }
    /* 板块通用 */
    .section {
      padding: 80px 0;
      scroll-margin-top: 80px;
    }
    .dark-section {
      background: var(--deep-bg);
      color: white;
    }
    .dark-panel {
      background: var(--panel-bg);
    }
    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.3;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, rgba(0,230,118,0.12), transparent 60%), var(--deep-bg);
      position: relative;
      overflow: hidden;
    }
    .hero-glow {
      position: absolute;
      right: -10%;
      top: 10%;
      width: 600px;
      height: 600px;
      background: radial-gradient(circle, rgba(0,230,118,0.2) 0%, transparent 70%);
    }
    .hero-content {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-text h1 {
      font-size: 3.2rem;
      color: white;
      margin-bottom: 20px;
      letter-spacing: 1px;
    }
    .hero-highlight {
      color: var(--primary);
      text-shadow: 0 0 18px rgba(0,230,118,0.35);
    }
    .hero-sub {
      font-size: 1.2rem;
      color: #cfd4e0;
      margin-bottom: 32px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: linear-gradient(135deg, var(--primary), #00C853);
      border: none;
      color: #0a0e14;
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: 0.25s;
      box-shadow: var(--shadow-glow);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }
    .btn-primary:hover {
      filter: brightness(1.1);
      box-shadow: 0 0 28px rgba(0,230,118,0.5);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 30px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      transition: 0.2s;
      text-decoration: none;
    }
    .btn-outline:hover {
      background: rgba(0,230,118,0.08);
    }
    .hero-img-example {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      height: 380px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
      border: 1px solid rgba(255,255,255,0.1);
    }
    @media (max-width: 768px) {
      .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-text h1 {
        font-size: 2.4rem;
      }
      .btn-group {
        justify-content: center;
      }
      .hero-img-example {
        height: 260px;
      }
    }
    /* 卡片网格 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: white;
      border-radius: var(--radius);
      padding: 28px 22px;
      box-shadow: var(--shadow-md);
      transition: var(--transition);
    }
    .card:hover {
      transform: translateY(-5px);
      box-shadow: 0 12px 32px rgba(0,0,0,0.12);
    }
    .card-icon {
      width: 48px;
      height: 48px;
      background: linear-gradient(145deg, #00E676, #00A844);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 1.5rem;
      margin-bottom: 20px;
    }
    .section-title {
      font-size: 2.2rem;
      margin-bottom: 16px;
      font-weight: 700;
    }
    @media (max-width: 768px) {
      .card-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 手风琴 */
    .faq-item {
      border-bottom: 1px solid #e0e5ec;
    }
    .faq-question {
      width: 100%;
      text-align: left;
      padding: 18px 8px;
      font-weight: 600;
      background: transparent;
      border: none;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      font-size: 1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding: 0 8px;
    }
    .footer {
      background: #0a0c14;
      color: #ccc;
      padding: 60px 0 20px;
    }
    .footer a {
      color: #aaa;
      text-decoration: none;
    }