#header {
    position: relative;
    overflow: hidden;
}
.dark-mode #header {
    background: black;
}

#header::before {
    content: "";
    position: absolute;
    top: -10%;
    left: -10%;
    width: 120%;
    height: 120%;
    background: var(--intro-bg) center center/cover;
    filter: blur(8px);
    z-index: -1;
    transform: scale(1.1);
}