/**
 * 灵极乌托邦 - 教程页面公共样式
 * 包含：CSS变量、导航栏、移动端菜单、模态框
 * 由 scripts/extract_tutorials_css.py 自动提取
 * 版本：v2.5.12
 */

    :root {
      --bg: #050508;
      --accent: #CCFF00;
      --accent-cyan: #CCFF00;
      --panel: #0a0a0f;
      --gold: #CCFF00;
      --brand-primary: #CCFF00;
      --brand-dim: #a8d900;
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      color: #fff;
      font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.8)), url('https://cdn.wutuobangai.com/assets/bg/bg-tutorials.webp') no-repeat center center fixed;
      background-size: cover;
    }

    a {
      color: inherit;
      text-decoration: none;
    }

    .navbar {
      position: fixed;
      top: 0;
      width: 100%;
      height: 72px;
      background: rgba(10, 10, 10, 0.7);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.1);
      z-index: 1000;
    }

    .navbar-inner {
      height: 100%;
      max-width: 1600px;
      margin: 0 auto;
      padding: 0 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 24px;
    }

    .nav-left,
    .nav-right {
      display: flex;
      align-items: center;
      gap: 12px;
      flex: 0 0 auto;
    }

    .nav-center {
      flex: 1 1 auto;
      display: flex;
      align-items: center;
      justify-content: center;
      min-width: 0;
    }

    .nav-logo {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 20px;
      font-weight: 700;
      color: #fff;
      transition: 0.3s;
    }

    .nav-logo:hover {
      color: var(--accent-cyan);
    }

    .nav-logo img {
      height: 38px;
      width: auto;
      mix-blend-mode: screen;
      filter: drop-shadow(0 0 10px var(--accent-cyan));
    }

    .nav-links {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 8px;
      font-size: 14px;
      font-weight: 500;
      flex-wrap: wrap;
      max-width: 1100px;
    }

    .nav-links a {
      padding: 10px 16px;
      color: #ccc;
      border-radius: 6px;
      transition: all 0.25s ease;
    }

    .nav-links a:hover {
      color: #fff;
      background: rgba(204, 255, 0, 0.08);
    }

    .nav-links > a.active,
    .nav-dropdown.is-active .nav-dropdown-toggle {
      color: var(--gold);
      background: rgba(204, 255, 0, 0.1);
    }

    .nav-dropdown {
      position: relative;
      display: flex;
      align-items: center;
    }

    .nav-dropdown::after {
      content: '';
      position: absolute;
      left: 0;
      right: 0;
      top: 100%;
      height: 16px;
    }

    .nav-dropdown-toggle {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      white-space: nowrap;
    }

    .nav-dropdown-toggle::after {
      content: '▾';
      font-size: 10px;
      opacity: 0.75;
      transition: transform 0.22s ease;
    }

    .nav-dropdown:hover .nav-dropdown-toggle::after,
    .nav-dropdown:focus-within .nav-dropdown-toggle::after {
      transform: rotate(180deg);
    }

    .nav-dropdown-panel {
      position: absolute;
      top: calc(100% + 12px);
      left: 50%;
      width: min(720px, 76vw);
      min-width: 620px;
      padding: 14px;
      border-radius: 20px;
      border: 1px solid rgba(255,255,255,0.08);
      background: linear-gradient(180deg, rgba(12,14,20,0.98) 0%, rgba(8,10,15,0.98) 100%);
      box-shadow: 0 24px 60px rgba(0,0,0,0.45);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      transform: translateX(-50%) translateY(10px);
      opacity: 0;
      visibility: hidden;
      pointer-events: none;
      transition: all 0.24s ease;
      z-index: 1200;
    }

    .nav-dropdown:hover .nav-dropdown-panel,
    .nav-dropdown:focus-within .nav-dropdown-panel {
      transform: translateX(-50%) translateY(0);
      opacity: 1;
      visibility: visible;
      pointer-events: auto;
    }

    .nav-dropdown-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 10px;
    }

    .nav-dropdown-item {
      display: block;
      padding: 12px 14px;
      border-radius: 14px;
      border: 1px solid rgba(255,255,255,0.08);
      background: rgba(255,255,255,0.03);
      transition: all 0.22s ease;
    }

    .nav-dropdown-item:hover {
      border-color: rgba(204,255,0,0.28);
      background: rgba(204,255,0,0.08);
      transform: translateY(-2px);
    }

    .nav-dropdown-item strong {
      display: block;
      margin-bottom: 4px;
      font-size: 13px;
      color: #fff;
    }

    .nav-dropdown-item span {
      display: block;
      font-size: 12px;
      line-height: 1.55;
      color: rgba(255,255,255,0.55);
    }

    .nav-dropdown-item.is-featured {
      grid-column: 1 / -1;
      background: linear-gradient(135deg, rgba(204,255,0,0.14), rgba(255,255,255,0.03));
      border-color: rgba(204,255,0,0.24);
    }

    .nav-dropdown-item.is-featured strong {
      color: var(--gold);
    }

    /* 会员订阅 VIP 金色样式 */
    .nav-links a.nav-link-vip {
      color: var(--gold);
      background: rgba(255, 215, 0, 0.15);
      font-weight: 700;
      text-shadow: 0 0 10px rgba(255, 215, 0, 0.6);
    }

    .nav-links a.nav-link-vip:hover {
      color: #D4FF00;
      background: rgba(204, 255, 0, 0.25);
      text-shadow: 0 0 15px rgba(255, 215, 0, 0.8);
    }

    .btn {
      padding: 10px 20px;
      font-size: 14px;
      font-weight: 600;
      border-radius: 8px;
      cursor: pointer;
      border: 1px solid rgba(255, 255, 255, 0.15);
      background: rgba(255, 255, 255, 0.06);
      color: #fff;
      transition: all 0.25s ease;
    }

    .btn:hover {
      border-color: rgba(204, 255, 0, 0.5);
      background: rgba(204, 255, 0, 0.12);
      color: var(--accent-cyan);
    }

    .btn-contact {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 10px 20px;
      font-size: 14px;
      font-weight: 700;
      border: none;
      border-radius: 8px;
      cursor: pointer;
      color: #fff !important;
      background: linear-gradient(135deg, #CCFF00 0%, #a8d900 100%);
      box-shadow: 0 0 20px rgba(204, 255, 0, 0.5);
      transition: all 0.3s ease;
    }

    .btn-contact:hover {
      transform: scale(1.05);
      filter: brightness(1.15);
      color: #fff !important;
    }

    .btn-contact svg {
      width: 18px;
      height: 18px;
    }

    .nav-mobile-actions {
      display: none;
      align-items: center;
      gap: 12px;
    }

    .btn-contact-icon {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 42px;
      height: 42px;
      border: none;
      border-radius: 10px;
      cursor: pointer;
      background: linear-gradient(135deg, #CCFF00 0%, #a8d900 100%);
      color: #fff;
      box-shadow: 0 0 16px rgba(204, 255, 0, 0.5);
    }

    .btn-contact-icon svg {
      width: 20px;
      height: 20px;
    }

    .nav-hamburger {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 42px;
      height: 42px;
      border: 1px solid rgba(255, 255, 255, 0.2);
      border-radius: 10px;
      background: rgba(255, 255, 255, 0.06);
      color: #CCFF00;
      font-size: 22px;
      cursor: pointer;
      transition: all 0.25s ease;
    }

    .nav-hamburger:hover {
      background: rgba(204, 255, 0, 0.12);
      border-color: rgba(204, 255, 0, 0.4);
    }

    .mobile-menu-overlay {
      position: fixed;
      inset: 0;
      z-index: 9999;
      visibility: hidden;
      opacity: 0;
      transition: opacity 0.35s ease, visibility 0.35s ease;
    }

    .mobile-menu-overlay.open {
      visibility: visible;
      opacity: 1;
    }

    .mobile-menu-backdrop {
      position: absolute;
      inset: 0;
      background: rgba(0, 0, 0, 0.6);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
    }

    .mobile-menu-panel {
      position: absolute;
      top: 0;
      right: 0;
      width: min(320px, 85vw);
      max-width: 320px;
      height: 100%;
      background: rgba(10, 10, 10, 0.85);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      border-left: 1px solid rgba(255, 255, 255, 0.1);
      box-shadow: -20px 0 60px rgba(0, 0, 0, 0.5);
      padding: 80px 24px 32px;
      overflow-y: auto;
      transform: translateX(100%);
      transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    }

    .mobile-menu-overlay.open .mobile-menu-panel {
      transform: translateX(0);
    }

    .mobile-menu-panel a {
      display: block;
      padding: 14px 16px;
      color: #ccc;
      font-size: 16px;
      font-weight: 500;
      border-radius: 10px;
      margin-bottom: 4px;
      transition: all 0.25s ease;
    }

    .mobile-menu-panel a:hover {
      color: #fff;
      background: rgba(204, 255, 0, 0.1);
    }

    .mobile-menu-panel a.nav-link-vip {
      color: var(--gold);
      background: rgba(255, 215, 0, 0.15);
      font-weight: 700;
    }

    .mobile-menu-panel a.nav-link-vip:hover {
      color: #D4FF00;
      background: rgba(204, 255, 0, 0.25);
    }

    .mobile-menu-panel .menu-divider {
      height: 1px;
      background: rgba(255, 255, 255, 0.1);
      margin: 16px 0;
    }

    .mobile-menu-panel .menu-section-title {
      font-size: 12px;
      color: rgba(255, 255, 255, 0.5);
      text-transform: uppercase;
      letter-spacing: 1px;
      padding: 8px 16px 4px;
      margin-top: 8px;
    }

    .top-spacer {
      height: 72px;
    }

    .modal-overlay {
      position: fixed;
      inset: 0;
      background: rgba(0, 0, 0, 0.92);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      display: none;
      justify-content: center;
      align-items: center;
      z-index: 10000;
    }

    .modal-overlay.show {
      display: flex;
    }

    .modal-box {
      background: linear-gradient(145deg, #141414, #0a0a0a);
      padding: 40px;
      border-radius: 24px;
      border: 1px solid var(--accent-cyan);
      text-align: center;
      max-width: 440px;
      width: 90%;
      box-shadow: 0 0 100px rgba(204, 255, 0, 0.25);
      position: relative;
    }

    .close-btn {
      position: absolute;
      top: 16px;
      right: 20px;
      font-size: 32px;
      color: rgba(255, 255, 255, 0.6);
      cursor: pointer;
      transition: 0.25s;
      line-height: 1;
      width: 32px;
      height: 32px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
    }

    .close-btn:hover {
      color: var(--accent-cyan);
      background: rgba(204, 255, 0, 0.1);
    }

    @media (max-width: 768px) {
      body {
        background-attachment: scroll;
        background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.8)), url('https://cdn.wutuobangai.com/assets/bg/bg-tutorials.m.webp') no-repeat center center fixed;
        background-size: cover;
      }

      .navbar-inner {
        padding: 0 16px;
      }

      .nav-logo {
        font-size: 16px;
      }

      .nav-logo img {
        height: 30px;
      }

      .nav-links {
        display: none;
      }

      .nav-right {
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
      }

      .nav-mobile-actions {
        display: flex;
      }

      .navbar {
        height: 60px;
      }

      .top-spacer {
        height: 60px;
      }

      .mobile-menu-panel a {
        min-height: 44px;
        font-size: 16px;
        padding: 14px 20px;
      }

      .mobile-menu-panel .menu-section-title {
        font-size: 16px;
      }
    }