style.css

body {
    font-size: 14px;
    font-family: 'Courier New', Courier, monospace;
}

.card-design
{
    /*lets add some borders round*/
    border: 0px;
    border-radius: 8px;
    box-shadow: 2px 2px 6px 1px #aaa;
}

.container {
    width: 400px;
    min-width: 320px;
    height: 500px;
    min-height: 480;
    margin: 50px auto;
}

.container > header
{
    text-align: center;
    height: 40px;
    border-top-left-radius: 8px;
    border-top-right-radius: 8px;
    background-color: #98b5fc;
}

.container > header > h1
{
    margin: 0;
    padding: 4px;
    color: white;
    text-shadow: 2px 2px #7b5fa8;
}

section.math-box
{
    width: 100%;
    height: 50px;
}

.math-box > .math-display
{
    width: 99%;
    height: 100%;
    font-size: 24px;
    border: 0;
    border-bottom: 1px solid #98b5fc;
    text-align: right;
}

.keyboard
{
    text-align: center;
    max-width: 70%;
    margin-top: 20px;
    float: left;
}

.keyboard > .keys
{
    width: 60px;
    height: 60px;
    margin: 5px;
}

.ops
{
    text-align: center;
    float: left;
    width: 10%;
}