/* ===== 重置 & 全局 ===== */
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    :root {
      --primary: #6C5CE7;
      --secondary: #00D2FF;
      --accent: #FF6B9D;
      --bg-dark: #0A0A0F;
      --bg-light: #F7F7FA;
      --text-white: #FFFFFF;
      --text-dark: #1A1A1A;
      --text-muted: #A0A0B0;
      --card-bg-dark: rgba(255, 255, 255, 0.04);
      --card-border-dark: rgba(255, 255, 255, 0.08);
      --radius-card: 16px;
      --radius-btn: 12px;
      --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      --font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', '思源黑体', sans-serif;
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-family);
      background-color: var(--bg-dark);
      color: var(--text-white);
      line-height: 1.6;
      overflow-x: hidden;
    }

    /* 浅色模式自动切换 */
    @media (prefers-color-scheme: light) {
      body {
        background-color: var(--bg-light);
        color: var(--text-dark);
      }
      .text-muted {
        color: #6B6B7B !important;
      }
      .download-card {
        background: #FFFFFF !important;
        border-color: rgba(0, 0, 0, 0.08) !important;
      }
      .download-card .meta {
        color: #6B6B7B !important;
      }
      .faq-item {
        background: rgba(0, 0, 0, 0.02) !important;
        border-color: rgba(0, 0, 0, 0.06) !important;
      }
      .footer-bg {
        background: #F0F0F5 !important;
      }
      .nav-bg {
        background: rgba(247, 247, 250, 0.85) !important;
      }
      .btn-secondary {
        color: var(--text-dark) !important;
        border-color: rgba(0, 0, 0, 0.15) !important;
      }
      .btn-secondary:hover {
        border-color: var(--primary) !important;
        background: rgba(108, 92, 231, 0.05) !important;
      }
      .step-item {
        background: rgba(0, 0, 0, 0.02) !important;
        border-color: rgba(0, 0, 0, 0.06) !important;
      }
    }

    /* ===== 通用工具 ===== */
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .text-gradient {
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .btn-primary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      color: #FFFFFF;
      font-weight: 700;
      font-size: 16px;
      text-decoration: none;
      transition: var(--transition);
      border: none;
      cursor: pointer;
      box-shadow: 0 4px 20px rgba(108, 92, 231, 0.3);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 8px 30px rgba(108, 92, 231, 0.5);
    }

    .btn-secondary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      background: transparent;
      color: var(--text-white);
      font-weight: 600;
      font-size: 16px;
      text-decoration: none;
      transition: var(--transition);
      border: 2px solid rgba(255, 255, 255, 0.2);
      cursor: pointer;
    }

    .btn-secondary:hover {
      border-color: var(--primary);
      background: rgba(108, 92, 231, 0.1);
      transform: translateY(-2px);
    }

    .section-title {
      font-size: 40px;
      font-weight: 800;
      text-align: center;
      margin-bottom: 16px;
      letter-spacing: -0.02em;
    }

    .section-subtitle {
      font-size: 18px;
      color: var(--text-muted);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 48px;
    }

    @media (max-width: 768px) {
      .section-title {
        font-size: 28px;
      }
      .section-subtitle {
        font-size: 16px;
        margin-bottom: 32px;
      }
    }

    /* ===== 导航栏 ===== */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      z-index: 1000;
      height: 64px;
      display: flex;
      align-items: center;
      transition: var(--transition);
      background: transparent;
    }

    .navbar.scrolled {
      background: rgba(10, 10, 15, 0.8);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
      border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }

    @media (prefers-color-scheme: light) {
      .navbar.scrolled {
        background: rgba(247, 247, 250, 0.85);
        border-bottom: 1px solid rgba(0, 0, 0, 0.05);
        box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
      }
    }

    .navbar .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .nav-logo {
      display: flex;
      align-items: center;
      gap: 10px;
      text-decoration: none;
      color: inherit;
      font-weight: 800;
      font-size: 22px;
    }

    .nav-logo img {
      height: 36px;
      width: auto;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-menu a {
      text-decoration: none;
      color: var(--text-muted);
      font-weight: 500;
      font-size: 15px;
      transition: var(--transition);
      position: relative;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--text-white);
    }

    @media (prefers-color-scheme: light) {
      .nav-menu a:hover,
      .nav-menu a.active {
        color: var(--text-dark);
      }
    }

    .nav-menu a.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      right: 0;
      height: 2px;
      background: linear-gradient(90deg, var(--primary), var(--secondary));
      border-radius: 2px;
    }

    .nav-actions {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .nav-actions .btn-login {
      text-decoration: none;
      color: var(--text-muted);
      font-weight: 500;
      font-size: 15px;
      transition: var(--transition);
    }

    .nav-actions .btn-login:hover {
      color: var(--text-white);
    }

    @media (prefers-color-scheme: light) {
      .nav-actions .btn-login:hover {
        color: var(--text-dark);
      }
    }

    .nav-actions .btn-download-sm {
      padding: 8px 20px;
      font-size: 14px;
      border-radius: 10px;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }

    .hamburger span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text-white);
      border-radius: 2px;
      transition: var(--transition);
    }

    @media (prefers-color-scheme: light) {
      .hamburger span {
        background: var(--text-dark);
      }
    }

    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(10, 10, 15, 0.95);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
      }
      .nav-menu.open {
        display: flex;
      }
      @media (prefers-color-scheme: light) {
        .nav-menu {
          background: rgba(247, 247, 250, 0.95);
        }
      }
      .hamburger {
        display: flex;
      }
      .nav-actions .btn-login {
        display: none;
      }
      .nav-actions .btn-download-sm {
        padding: 6px 14px;
        font-size: 13px;
      }
    }

    /* ===== 下载页首屏 ===== */
    .download-hero {
      padding: 140px 0 80px;
      background: radial-gradient(ellipse at 30% 40%, rgba(108, 92, 231, 0.18) 0%, transparent 60%),
                  radial-gradient(ellipse at 70% 60%, rgba(0, 210, 255, 0.12) 0%, transparent 55%),
                  var(--bg-dark);
      text-align: center;
      position: relative;
      overflow: hidden;
    }

    @media (prefers-color-scheme: light) {
      .download-hero {
        background: radial-gradient(ellipse at 30% 40%, rgba(108, 92, 231, 0.08) 0%, transparent 60%),
                    radial-gradient(ellipse at 70% 60%, rgba(0, 210, 255, 0.06) 0%, transparent 55%),
                    var(--bg-light);
      }
    }

    .download-hero h1 {
      font-size: 52px;
      font-weight: 800;
      letter-spacing: -0.03em;
      margin-bottom: 16px;
      line-height: 1.15;
    }

    .download-hero .sub {
      font-size: 18px;
      color: var(--text-muted);
      max-width: 600px;
      margin: 0 auto 40px;
      line-height: 1.7;
    }

    .version-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 8px 20px;
      border-radius: 100px;
      background: rgba(108, 92, 231, 0.15);
      border: 1px solid rgba(108, 92, 231, 0.3);
      font-size: 14px;
      color: var(--text-white);
      margin-bottom: 32px;
    }

    @media (prefers-color-scheme: light) {
      .version-badge {
        color: var(--text-dark);
      }
    }

    .version-badge .dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: var(--secondary);
      animation: pulse 1.5s ease-in-out infinite;
    }

    @keyframes pulse {
      0%, 100% { opacity: 1; transform: scale(1); }
      50% { opacity: 0.5; transform: scale(1.3); }
    }

    /* ===== 平台下载卡片 ===== */
    .platforms {
      padding: 40px 0 100px;
      background: var(--bg-dark);
    }

    @media (prefers-color-scheme: light) {
      .platforms {
        background: var(--bg-light);
      }
    }

    .platforms-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
      max-width: 900px;
      margin: 0 auto;
    }

    @media (max-width: 768px) {
      .platforms-grid {
        grid-template-columns: 1fr;
      }
    }

    .download-card {
      background: rgba(255, 255, 255, 0.04);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: var(--radius-card);
      padding: 32px;
      display: flex;
      flex-direction: column;
      gap: 16px;
      transition: var(--transition);
      position: relative;
      overflow: hidden;
    }

    .download-card:hover {
      transform: translateY(-4px);
      border-color: rgba(108, 92, 231, 0.5);
      box-shadow: 0 12px 40px rgba(108, 92, 231, 0.15);
    }

    .download-card .card-header {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .download-card .card-header .icon {
      font-size: 40px;
      width: 64px;
      height: 64px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 16px;
      background: rgba(108, 92, 231, 0.15);
      border: 1px solid rgba(108, 92, 231, 0.2);
      flex-shrink: 0;
    }

    .download-card .card-header .info h3 {
      font-size: 22px;
      font-weight: 700;
      margin-bottom: 4px;
    }

    .download-card .card-header .info .meta {
      font-size: 14px;
      color: var(--text-muted);
    }

    .download-card .card-body {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .download-card .card-body .req {
      font-size: 13px;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .download-card .card-body .req span {
      color: var(--secondary);
    }

    .download-card .card-actions {
      display: flex;
      gap: 12px;
      flex-wrap: wrap;
      margin-top: 4px;
    }

    .download-card .card-actions .btn-download {
      flex: 1;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 12px 24px;
      border-radius: var(--radius-btn);
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      color: #FFFFFF;
      font-weight: 700;
      font-size: 15px;
      text-decoration: none;
      transition: var(--transition);
      min-width: 140px;
    }

    .download-card .card-actions .btn-download:hover {
      box-shadow: 0 8px 25px rgba(108, 92, 231, 0.4);
      transform: translateY(-2px);
    }

    .download-card .card-actions .btn-alt {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 20px;
      border-radius: var(--radius-btn);
      background: rgba(255, 255, 255, 0.06);
      border: 1px solid rgba(255, 255, 255, 0.1);
      color: var(--text-white);
      font-weight: 500;
      font-size: 14px;
      text-decoration: none;
      transition: var(--transition);
    }

    @media (prefers-color-scheme: light) {
      .download-card .card-actions .btn-alt {
        background: rgba(0, 0, 0, 0.03);
        border-color: rgba(0, 0, 0, 0.08);
        color: var(--text-dark);
      }
    }

    .download-card .card-actions .btn-alt:hover {
      border-color: var(--primary);
      background: rgba(108, 92, 231, 0.15);
    }

    /* ===== 二维码区域 ===== */
    .qr-section {
      padding: 60px 0 100px;
      background: #06060A;
      text-align: center;
    }

    @media (prefers-color-scheme: light) {
      .qr-section {
        background: #F0F0F5;
      }
    }

    .qr-section h2 {
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 12px;
    }

    .qr-section p {
      font-size: 16px;
      color: var(--text-muted);
      margin-bottom: 32px;
    }

    .qr-box {
      display: inline-flex;
      flex-direction: column;
      align-items: center;
      gap: 16px;
      padding: 32px 48px;
      border-radius: var(--radius-card);
      background: rgba(255, 255, 255, 0.04);
      border: 1px solid rgba(255, 255, 255, 0.08);
    }

    @media (prefers-color-scheme: light) {
      .qr-box {
        background: #FFFFFF;
        border-color: rgba(0, 0, 0, 0.08);
      }
    }

    .qr-box .qr-placeholder {
      width: 160px;
      height: 160px;
      border-radius: 12px;
      background: linear-gradient(135deg, rgba(108, 92, 231, 0.2), rgba(0, 210, 255, 0.15));
      border: 2px dashed rgba(108, 92, 231, 0.4);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 14px;
      color: var(--text-muted);
    }

    .qr-box .qr-label {
      font-size: 14px;
      color: var(--text-muted);
    }

    /* ===== 安装步骤 ===== */
    .install-steps {
      padding: 100px 0;
      background: var(--bg-dark);
    }

    @media (prefers-color-scheme: light) {
      .install-steps {
        background: var(--bg-light);
      }
    }

    .steps-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    @media (max-width: 1024px) {
      .steps-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 640px) {
      .steps-grid {
        grid-template-columns: 1fr;
      }
    }

    .step-item {
      background: rgba(255, 255, 255, 0.04);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      transition: var(--transition);
      position: relative;
    }

    .step-item:hover {
      border-color: rgba(108, 92, 231, 0.4);
      transform: translateY(-4px);
    }

    .step-item .step-num {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 36px;
      height: 36px;
      border-radius: 10px;
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      color: #FFFFFF;
      font-weight: 800;
      font-size: 16px;
      margin-bottom: 16px;
    }

    .step-item h4 {
      font-size: 17px;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .step-item p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* ===== 系统要求 ===== */
    .requirements {
      padding: 100px 0;
      background: #06060A;
    }

    @media (prefers-color-scheme: light) {
      .requirements {
        background: #F0F0F5;
      }
    }

    .req-table {
      max-width: 800px;
      margin: 0 auto;
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid rgba(255, 255, 255, 0.08);
    }

    @media (prefers-color-scheme: light) {
      .req-table {
        border-color: rgba(0, 0, 0, 0.08);
      }
    }

    .req-row {
      display: grid;
      grid-template-columns: 1fr 2fr;
      border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }

    @media (prefers-color-scheme: light) {
      .req-row {
        border-bottom-color: rgba(0, 0, 0, 0.06);
      }
    }

    .req-row:last-child {
      border-bottom: none;
    }

    .req-row .req-label {
      padding: 16px 24px;
      background: rgba(255, 255, 255, 0.03);
      font-weight: 600;
      font-size: 15px;
    }

    @media (prefers-color-scheme: light) {
      .req-row .req-label {
        background: rgba(0, 0, 0, 0.02);
      }
    }

    .req-row .req-value {
      padding: 16px 24px;
      font-size: 15px;
      color: var(--text-muted);
    }

    /* ===== 下载页FAQ ===== */
    .download-faq {
      padding: 100px 0;
      background: var(--bg-dark);
    }

    @media (prefers-color-scheme: light) {
      .download-faq {
        background: var(--bg-light);
      }
    }

    .faq-list {
      max-width: 800px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .faq-item {
      background: rgba(255, 255, 255, 0.04);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: var(--radius-card);
      padding: 24px 28px;
      transition: var(--transition);
    }

    .faq-item:hover {
      border-color: rgba(108, 92, 231, 0.4);
    }

    .faq-item .faq-q {
      font-size: 17px;
      font-weight: 700;
      margin-bottom: 10px;
      display: flex;
      align-items: flex-start;
      gap: 10px;
    }

    .faq-item .faq-q .num {
      color: var(--secondary);
      font-weight: 800;
      flex-shrink: 0;
    }

    .faq-item .faq-a {
      font-size: 15px;
      color: var(--text-muted);
      line-height: 1.7;
      padding-left: 28px;
    }

    /* ===== 底部CTA ===== */
    .bottom-cta {
      padding: 100px 0;
      background: linear-gradient(135deg, rgba(108, 92, 231, 0.15), rgba(0, 210, 255, 0.1));
      text-align: center;
    }

    .bottom-cta h2 {
      font-size: 36px;
      font-weight: 800;
      margin-bottom: 16px;
    }

    .bottom-cta p {
      font-size: 17px;
      color: var(--text-muted);
      margin-bottom: 32px;
    }

    .bottom-cta .cta-buttons {
      display: flex;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
    }

    @media (max-width: 768px) {
      .bottom-cta h2 {
        font-size: 26px;
      }
    }

    /* ===== 页脚 ===== */
    .footer {
      padding: 64px 0 32px;
      background: #06060A;
      border-top: 1px solid rgba(255, 255, 255, 0.05);
    }

    @media (prefers-color-scheme: light) {
      .footer {
        background: #F0F0F5;
        border-top: 1px solid rgba(0, 0, 0, 0.05);
      }
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 48px;
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
      }
    }

    @media (max-width: 480px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }

    .footer-brand {
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .footer-brand .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 22px;
      font-weight: 800;
      text-decoration: none;
      color: inherit;
    }

    .footer-brand .logo img {
      height: 32px;
    }

    .footer-brand p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
      max-width: 280px;
    }

    .footer-social {
      display: flex;
      gap: 12px;
      margin-top: 8px;
    }

    .footer-social a {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 36px;
      height: 36px;
      border-radius: 10px;
      background: rgba(255, 255, 255, 0.06);
      border: 1px solid rgba(255, 255, 255, 0.08);
      color: var(--text-muted);
      text-decoration: none;
      font-size: 16px;
      transition: var(--transition);
    }

    @media (prefers-color-scheme: light) {
      .footer-social a {
        background: rgba(0, 0, 0, 0.03);
        border-color: rgba(0, 0, 0, 0.06);
      }
    }

    .footer-social a:hover {
      border-color: var(--primary);
      color: var(--text-white);
      background: rgba(108, 92, 231, 0.2);
    }

    @media (prefers-color-scheme: light) {
      .footer-social a:hover {
        color: var(--text-dark);
      }
    }

    .footer-col h4 {
      font-size: 15px;
      font-weight: 700;
      margin-bottom: 16px;
    }

    .footer-col ul {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .footer-col ul li a {
      text-decoration: none;
      color: var(--text-muted);
      font-size: 14px;
      transition: var(--transition);
    }

    .footer-col ul li a:hover {
      color: var(--text-white);
    }

    @media (prefers-color-scheme: light) {
      .footer-col ul li a:hover {
        color: var(--text-dark);
      }
    }

    .footer-bottom {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      padding-top: 32px;
      border-top: 1px solid rgba(255, 255, 255, 0.05);
      font-size: 13px;
      color: var(--text-muted);
    }

    @media (prefers-color-scheme: light) {
      .footer-bottom {
        border-top-color: rgba(0, 0, 0, 0.05);
      }
    }

    .footer-bottom .lang-switch a {
      color: var(--text-muted);
      text-decoration: none;
      margin-left: 12px;
      transition: var(--transition);
    }

    .footer-bottom .lang-switch a:hover {
      color: var(--text-white);
    }

    @media (prefers-color-scheme: light) {
      .footer-bottom .lang-switch a:hover {
        color: var(--text-dark);
      }
    }

    /* ===== 滚动动画 ===== */
    .fade-in {
      opacity: 0;
      transform: translateY(30px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }

    .fade-in.visible {
      opacity: 1;
      transform: translateY(0);
    }

    @media (prefers-reduced-motion: reduce) {
      *,
      *::before,
      *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
      }
      .fade-in {
        opacity: 1;
        transform: none;
      }
    }