body {
    color: yellow;
    background-image: url('bg.jpg');
    background-size: 100%;
    margin: auto;
    text-align: center;
}

.yellow {
    color: yellow;
}

.yellow:hover {
    color: #9A9B9C;
}

.yellowbtn {
    cursor: pointer;
    border-radius: 10px;
    border-style: solid;
    border-color: yellow;
    background: #444444;
    color: white;
    font-size: 120%;
    max-width: 60%;
    width: 290px;
    height: 50px;
}

.yellowbtn:hover {
    background: #96969;
    color: #9A9B9C;
}