#canvas1 {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 800px;
    height: 700px;
    border: 3px solid white;
    z-index: 1;
}

body {
    background: black;
    margin: 0; /* Remove default body margin */
    overflow: hidden; /* Hide overflowing content */
}

#container {
    position: absolute;
    width: 800px;
    height: 700px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border: 3px solid white;
    z-index: 2;
}

#slider {
    width: 100%;
    position: absolute;
    bottom: 0;
    z-index: 3;
}

p {
    color: red;
    z-index: 30;
    position: absolute; 
}