.loader {
    border: 4px solid #f3f3f3;
    border-radius: 50%;
    border-top: 4px solid blue;
    border-bottom: 4px solid red;
    width: 40px;
    height: 40px;
    -webkit-animation: spin 2s linear infinite;
    animation: spin 2s linear infinite;
    margin-top: 5px;
    margin-left: 10px;
    display: none;
}