Hero section is overlapping the sidebar about animated-portfolio HOT 3 CLOSED

.bg{
    z-index: 999;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 400px;
    background-color: white;

    .links{
        position: absolute;
        height: 100%;
        width: 100%;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content:center;
        gap: 20px;

        a{
            font-size: 40px;
        }
    }
}

button{
    z-index: 999;
    position: fixed;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    top: 25px;
    left: 25px;
    background-color: transparent;
    border: none;
    cursor: pointer;
    
}