#matrix-canvases {
    position: relative;
    height: 610px;
    width: 800px;
}

#matrix-canvases canvas {
    position: absolute;
    top: 0;
    left: 0;
}

.matrix-entry {
    width: 3em;
}

table#form {
    margin:0 auto 1em auto;
}

table#form td {
    text-align: center;
}

.error {
    border: 1px solid red;
}