#matrix {
    position: fixed;
    z-index: -1;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: black;
}

#toggle-matrix {
    position: fixed;
    top: 10px;
    right: 10px;
    z-index: 1000;
    padding: 10px 15px;
    background-color: red;
    color: white;
    border: none;
    font-size: 14px;
    cursor: pointer;
    border-radius: 5px;
}