/* ===== 全局重置与基础 ===== */
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    html, body {
      font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
      background: #1a1e1a;
      color: #fff;
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }

    a {
      color: #e0e8e0 !important;
      text-decoration: none !important;
      transition: color 0.25s ease;
    }

    a:hover {
      color: #6fbf4c !important;
    }

    /* ===== 视频容器 ===== */
    .pc-banner, .mobile-banner {
      width: 100%;
      overflow: hidden;
      background: #0b0f0b;
      position: relative;
    }

    .mobile-banner { display: none; }

    .pc-banner video,
    .mobile-banner video {
      display: block;
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .pc-banner .video-ratio {
      position: relative;
      width: 100%;
      height: 0;
      padding-top: 56.25%;
    }

    .pc-banner .video-ratio video {
      position: absolute;
      top: 0;
      left: 0;
    }

    .mobile-banner .video-ratio {
      position: relative;
      width: 100%;
      height: 0;
      padding-top: 56.25%;
    }

    .mobile-banner .video-ratio video {
      position: absolute;
      top: 0;
      left: 0;
      object-fit: contain;
    }

    .mobile-banner .wechat-fallback-img {
      display: none;
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .mobile-banner.wechat-mode video { display: none; }
    .mobile-banner.wechat-mode .wechat-fallback-img { display: block; }

    /* ===== 固定LOGO ===== */
    .fixed-logo {
      position: fixed;
      top: 18px;
      left: 50%;
      transform: translateX(-50%);
      text-align: center;
      z-index: 9997;
      line-height: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      transition: left 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                  top 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                  transform 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                  gap 0.4s ease;
      pointer-events: none;
    }

    .fixed-logo .logo,
    .fixed-logo .logo-title { pointer-events: auto; }

    .fixed-logo.scrolled {
      top: 24px;
      left: 30px;
      transform: translateX(0);
      flex-direction: row;
      align-items: center;
      gap: 10px;
    }

    .logo {
      width: 72px;
      height: 72px;
      object-fit: contain;
      display: block;
      filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.3));
      transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                  height 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    }

    .fixed-logo.scrolled .logo { width: 46px; height: 46px; }

    .logo-title {
      color: #f0f7e8;
      font-size: 14px;
      font-weight: 500;
      white-space: nowrap;
      text-shadow: 0 1px 4px rgba(0, 0, 0, 0.5);
      letter-spacing: 0.4px;
      transition: font-size 0.4s ease;
    }

    .fixed-logo.scrolled .logo-title { font-size: 13px; }

    /* ===== 导航按钮 ===== */
    .nav-toggle {
      position: fixed;
      top: 30px;
      right: 30px;
      width: 48px;
      height: 48px;
      background: rgba(30, 40, 28, 0.7);
      border: 1px solid rgba(255, 255, 255, 0.15);
      border-radius: 50%;
      color: #fff;
      font-size: 22px;
      cursor: pointer;
      backdrop-filter: blur(8px);
      display: flex;
      align-items: center;
      justify-content: center;
      z-index: 9998;
      transition: background 0.25s ease, transform 0.25s ease;
    }

    .nav-toggle:hover {
      background: rgba(82, 149, 51, 0.75);
      transform: scale(1.05);
    }

    .nav-toggle:active {
      transform: scale(0.96);
    }

    /* ===== 弹出菜单 ===== */
    .nav-menu {
      position: fixed;
      top: 90px;
      right: 30px;
      background: rgba(18, 26, 16, 0.92);
      backdrop-filter: blur(12px);
      border-radius: 12px;
      padding: 8px 0;
      min-width: 150px;
      z-index: 9999;
      display: none;
      box-shadow: 0 12px 28px rgba(0, 0, 0, 0.5);
      border: 1px solid rgba(255, 255, 255, 0.08);
      overflow: hidden;
    }

    .nav-menu.active {
      display: block;
      animation: fadeIn 0.2s ease;
    }

    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(-6px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .nav-menu a {
      display: block;
      color: #e8f0e4 !important;
      font-size: 15px;
      padding: 11px 22px;
      transition: background 0.2s ease;
    }

    .nav-menu a:hover {
      background: rgba(82, 149, 51, 0.2);
      color: #fff !important;
    }

    /* ===== 素材下载区 ===== */
    .download-section {
      padding: 80px 24px 70px;
      max-width: 1280px;
      margin: 0 auto;
      position: relative;
    }

    .section-title {
      text-align: center;
      font-size: 42px;
      font-weight: 700;
      margin-bottom: 12px;
      background: linear-gradient(135deg, #fff 0%, #c8e6b0 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: -0.5px;
    }

    .sub-tip {
      text-align: center;
      font-size: 16px;
      color: #a0b89a;
      margin-bottom: 48px;
    }

    .bottom-desc-tip {
      text-align: center;
      font-size: 17px;
      color: #b8ccb0;
      margin-top: 56px;
      padding-top: 20px;
      border-top: 1px solid rgba(255, 255, 255, 0.06);
      letter-spacing: 0.5px;
    }

    .material-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }

    .material-item {
      background: rgba(40, 48, 38, 0.85);
      border-radius: 16px;
      overflow: hidden;
      transition: transform 0.3s ease, box-shadow 0.3s ease;
      border: 1px solid rgba(255, 255, 255, 0.08);
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
    }

    .material-item:hover {
      transform: translateY(-6px);
      box-shadow: 0 20px 36px rgba(0, 0, 0, 0.5);
      border-color: rgba(111, 191, 76, 0.25);
    }

    .img-wrap {
      width: 100%;
      height: 320px;
      overflow: hidden;
      position: relative;
      background: #1e241c;
    }

    .img-wrap::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(to top, rgba(0, 0, 0, 0.4) 0%, transparent 60%);
      pointer-events: none;
    }

    .material-img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.5s ease;
    }

    .img-wrap:hover .material-img { transform: scale(1.06); }

    .material-info { padding: 22px 22px 24px; }

    .material-name {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 18px;
      color: #fff;
      letter-spacing: 0.3px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .material-name::before {
      content: '';
      display: inline-block;
      width: 4px;
      height: 20px;
      background: #6fbf4c;
      border-radius: 3px;
    }

    .size-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
    }

    /* ===== 尺寸按钮 ===== */
    .size-btn {
      padding: 9px 20px;
      background: #529533;
      color: #fff !important;
      border: none;
      border-radius: 8px;
      font-size: 14px;
      font-weight: 500;
      cursor: pointer;
      transition: background 0.2s ease;
      letter-spacing: 0.3px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      line-height: 1;
    }

    .size-btn:hover {
      background: #3f7a26;
      color: #fff !important;
    }

    .size-btn:active {
      background: #356a1f;
    }

    /* ===== 页脚 ===== */
    footer {
      position: relative;
      color: #e0e8e0;
      padding: 70px 24px 35px;
      font-size: 15px;
      background-image: url('../images/footer-bg.jpg');
      background-size: cover;
      background-position: center;
      background-repeat: no-repeat;
      background-color: #121812;
    }

    footer::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: linear-gradient(135deg, rgba(10, 16, 8, 0.85) 0%, rgba(20, 28, 18, 0.92) 100%);
      z-index: 1;
    }

    .footer-container {
      max-width: 1280px;
      margin: 0 auto;
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
      margin-bottom: 50px;
      position: relative;
      z-index: 2;
    }

    .footer-col h4 {
      font-size: 20px;
      margin-bottom: 24px;
      color: #fff;
      font-weight: 600;
      position: relative;
      padding-bottom: 12px;
    }

    .footer-col h4::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 36px;
      height: 3px;
      background: #6fbf4c;
      border-radius: 3px;
    }

    .footer-col ul { list-style: none; }
    .footer-col ul li { margin-bottom: 14px; }

    .footer-col ul li a {
      color: #c8d8c0 !important;
      font-size: 15px;
      transition: color 0.2s ease;
      display: inline-block;
    }

    .footer-col ul li a:hover {
      color: #8fdc6b !important;
    }

    .footer-qrcodes { display: flex; gap: 20px; }
    .qrcode-item { text-align: center; }

    .qrcode-item img {
      width: 110px;
      height: 110px;
      object-fit: contain;
      background: #fff;
      border-radius: 12px;
      padding: 6px;
      box-shadow: 0 6px 16px rgba(0, 0, 0, 0.35);
    }

    .qrcode-item p {
      margin-top: 10px;
      color: #c0d4b8;
      font-size: 14px;
    }

    .footer-bottom {
      border-top: 1px solid rgba(255, 255, 255, 0.1);
      padding-top: 28px;
      text-align: center;
      color: #a8bca0;
      position: relative;
      z-index: 2;
      font-size: 14px;
    }

    .footer-links {
      margin-bottom: 16px;
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: 12px 24px;
    }

    .footer-links a { color: #d0e0c8 !important; font-weight: 500; }
    .footer-links a:hover { color: #8fdc6b !important; }

    .copyright-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
    }

    .copyright-row p { margin: 0; white-space: nowrap; }

    /* ===== 移动端适配 ===== */
    @media (max-width: 768px) {
      .pc-banner { display: none; }
      .mobile-banner { display: block; }

      .fixed-logo { top: 8px; gap: 2px; }
      .logo { width: 42px; height: 42px; }
      .logo-title { font-size: 11px; }

      .fixed-logo.scrolled {
        top: 14px;
        left: 16px;
        gap: 8px;
      }

      .fixed-logo.scrolled .logo { width: 36px; height: 36px; }
      .fixed-logo.scrolled .logo-title { font-size: 11px; }

      .nav-toggle {
        top: 12px;
        right: 16px;
        width: 44px;
        height: 44px;
        font-size: 20px;
      }

      .nav-menu {
        top: 66px;
        right: 16px;
        min-width: 140px;
        border-radius: 12px;
      }

      .nav-menu a { font-size: 14px; padding: 10px 18px; }

      .download-section { padding: 50px 16px 40px; }
      .section-title { font-size: 28px; margin-bottom: 6px; }
      .sub-tip { font-size: 14px; margin-bottom: 28px; }
      .bottom-desc-tip { font-size: 15px; margin-top: 32px; }

      .material-grid { grid-template-columns: 1fr; gap: 22px; }
      .img-wrap { height: 220px; }
      .material-info { padding: 18px 18px 20px; }
      .material-name { font-size: 19px; margin-bottom: 14px; }

      .size-btn {
        flex: 1 0 calc(25% - 7.5px);
        text-align: center;
        padding: 10px 6px;
        font-size: 13px;
      }

      footer { padding: 50px 16px 25px; }

      .footer-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 28px;
      }

      .footer-col h4 { font-size: 18px; margin-bottom: 18px; }
      .footer-col h4::after { width: 28px; height: 2px; }
      .footer-col ul li a { font-size: 14px; }

      .footer-qrcodes {
        justify-content: flex-start;
        flex-wrap: wrap;
        gap: 14px;
      }

      .qrcode-item img { width: 90px; height: 90px; }

      .copyright-row { flex-direction: column; gap: 8px; }
      .footer-links { gap: 8px 16px; }
    }

    /* ===== 自定义提示框 ===== */
    #customAlert {
      box-shadow: 0 12px 28px rgba(0, 0, 0, 0.5) !important;
      border: 1px solid rgba(255, 255, 255, 0.12) !important;
      background: rgba(20, 30, 16, 0.95) !important;
      border-radius: 14px !important;
      font-weight: 500 !important;
      padding: 20px 28px !important;
    }

    /* 滚动条美化 */
    ::-webkit-scrollbar { width: 8px; }
    ::-webkit-scrollbar-track { background: #1a1e1a; }
    ::-webkit-scrollbar-thumb { background: #3f5a33; border-radius: 10px; }
    ::-webkit-scrollbar-thumb:hover { background: #529533; }