.crt {
    position: fixed;
    overflow: hidden;
    height: 100vh;
    z-index: 997;
}

/* 扫描线效果 */
.crt::before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom,
            transparent 50%,
            rgba(0, 100, 0, 0.2) 50%);
    background-size: 100% 2px;
    pointer-events: none;
    z-index: 998;
    animation: scanlines 50s linear infinite;
}

@keyframes scanlines {
    0% {
        background-position: 0 0;
    }
    
    100% {
        background-position: 0 100%;
    }
}

/* 屏幕闪烁效果 */
.crt::after {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.3);
    opacity: 0;
    pointer-events: none;
    z-index: 999;
    animation: crt-flicker 1s infinite;
}

@keyframes crt-flicker {
    0% {
        opacity: 0.2;
    }
    
    50% {
        opacity: 0.1;
    }
    
    100% {
        opacity: 0.2;
    }
}