* {
    box-sizing: border-box;
}

/* Your css goes here */
header {
    background-image: url("junkshelf.jpg");
    height: 200px;
    background-size: contain;
}
header h1 {
    margin: 0;
    color: white;
    text-align: center;
    font-size: 6em;
    line-height: 2em;
}
footer {
    margin-top: 20px;
    border-top: 3px solid red;
    text-align: center;
    font-style: italic;
}
table.coin {
   background-color: purple;
   font-family: sans-serif;
width: 100%;
color:chartreuse;
}
table.coin th, table.coin td {
    border: 1px solid black;
    padding: 8px;
    text-align: left;
}



table.coin th {
    background-color: darkblue;
    color: white;
    font-weight: bold;
    padding: 12px;
    border: 1px solid black;
}
@media only screen and (max-width: 719px) {
    table.coin {
        width: 100%;
    }

    table.coin thead {
        display: none;
    }

    table.coin,
    table.coin tbody,
    table.coin tr,
    table.coin td {
        display: block;
    }

    table.coin tr {
        margin-bottom: 20px;
        border: 10px solid black;
    }
table.coin th {
display: none;
}
}