/* 弹窗背景遮罩 - 改为更透明的黑色背景 */
    .popup-overlay {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: rgba(0, 0, 0, 0.5); /* 降低不透明度 */
        display: flex;
        justify-content: center;
        align-items: center;
        z-index: 1000;
        opacity: 0;
        animation: fadeIn 0.5s ease-out forwards;
    }
    
    @keyframes fadeIn {
        from { opacity: 0; }
        to { opacity: 1; }
    }
    
    /* 弹窗容器 - 改为半透明玻璃态效果 */
    .tech-popup {
        width: 600px;
        background: rgba(26, 26, 58, 0.7); /* 半透明背景 */
        backdrop-filter: blur(10px); /* 毛玻璃效果 */
        border-radius: 15px;
        box-shadow: 0 0 30px rgba(0, 150, 255, 0.2); /* 降低阴影不透明度 */
        border: 1px solid rgba(0, 150, 255, 0.3); /* 降低边框不透明度 */
        overflow: hidden;
        transform: scale(0.8);
        animation: popIn 0.5s ease-out forwards;
    }
    
    @keyframes popIn {
        from { transform: scale(0.8); }
        to { transform: scale(1); }
    }
    
    /* 弹窗头部 - 改为半透明 */
    .popup-header {
        background: rgba(0, 102, 204, 0.7); /* 半透明头部 */
        padding: 20px;
        text-align: center;
        border-bottom: 1px solid rgba(0, 150, 255, 0.3);
    }
    
    .popup-header h3 {
        margin: 0;
        color: #ffffff;
        font-size: 24px;
        letter-spacing: 1px;
        text-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
    }
    
    /* 弹窗内容 */
    .popup-content {
        padding: 25px;
    }
    
    .popup-content p {
        margin: 15px 0;
        font-size: 16px;
        line-height: 1.6;
        color: #e0e0ff; /* 调整文字颜色提高可读性 */
        text-align: center;
    }
    
    .highlight {
        color: #00ffff;
        font-weight: bold;
        text-shadow: 0 0 5px rgba(0, 255, 255, 0.5);
    }
    
    /* 按钮区域 */
    .button-group {
        display: flex;
        justify-content: center;
        gap: 20px;
        margin-top: 25px;
    }
    
    .tech-button {
        background: rgba(0, 102, 204, 0.7); /* 半透明按钮 */
        color: white;
        border: none;
        padding: 12px 30px;
        border-radius: 30px;
        font-size: 16px;
        cursor: pointer;
        transition: all 0.3s ease;
        box-shadow: 0 0 10px rgba(0, 150, 255, 0.3); /* 降低阴影不透明度 */
        position: relative;
        overflow: hidden;
    }
    
    .tech-button:hover {
        background: rgba(0, 102, 204, 0.9); /* 悬停时增加不透明度 */
        transform: translateY(-2px);
        box-shadow: 0 5px 15px rgba(0, 150, 255, 0.5);
    }
    
    .tech-button:active {
        transform: translateY(0);
    }
    
    .tech-button::before {
        content: '';
        position: absolute;
        top: 0;
        left: -100%;
        width: 100%;
        height: 100%;
        background: linear-gradient(
            120deg,
            transparent,
            rgba(255, 255, 255, 0.2),
            transparent
        );
        transition: 0.5s;
    }
    
    .tech-button:hover::before {
        left: 100%;
    }
    
    .tech-button a {
        color: white;
        text-decoration: none;
    }
    
    /* 关闭按钮 - 保持类似风格但更透明 */
    .close-btn {
        position: absolute;
        top: 15px;
        right: 15px;
        width: 30px;
        height: 30px;
        background: rgba(255, 255, 255, 0.1);
        border-radius: 50%;
        display: flex;
        justify-content: center;
        align-items: center;
        cursor: pointer;
        transition: all 0.3s ease;
    }
    
    .close-btn:hover {
        background: rgba(255, 0, 0, 0.2); /* 降低悬停不透明度 */
        transform: rotate(90deg);
    }
    
    .close-btn::before, .close-btn::after {
        content: '';
        position: absolute;
        width: 15px;
        height: 2px;
        background: white;
    }
    
    .close-btn::before {
        transform: rotate(45deg);
    }
    
    .close-btn::after {
        transform: rotate(-45deg);
    }