style.css

body, #solveButton, #clearButton {
    background-image: url("background.jpg");
    background-color: blanchedalmond;
    font-family: 'Bacasime Antique', serif;
}
#container {
    text-align: center;
    padding-left: 100px;
    padding-right: 100px;
}
table {
    border-collapse: collapse;
    font-size: 2em;
    margin: 0 auto;
}
colgroup, tbody {
    border: solid medium;
}
td {
    border: solid thin;
    height: 1.4em;
    width: 1.4em;
    text-align: center;
    padding: 0;
}
button {
    margin-top: 15px;
    font-size: 1.5em;
}
.padd, #instr, #buttons {
    padding-bottom: 20px;
}
#heading1 {
    font-size: 35px;
}
#info, #fact, #instr, #solveButton, #clearButton {
    font-size: 20px;
}
#solveButton, #clearButton {
    background-color: bisque;
    background-image: none;
    text-align: center;
    width: 150px;
    border-radius: 7px;
}
#container {
    animation-name: animate;
    animation-duration: 3s;
    animation-iteration-count: 1;
    animation-timing-function: ease-in-out;
}
@keyframes animate {
    from {
       opacity: 0;
    }
    to {
        opacity: 1;
    }    
}