.btnloader {
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    position: relative;
    display: inline-block;
}

.btnloader .loader {
    border: 3px solid #f3f3f3;
    border-radius: 50%;
    border-top: 3px solid #3498db;
    width: 15px;
    height: 15px;
    animation: spin 1s linear infinite;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    display: none;
}


@keyframes spin {
    0% { transform: translate(-50%, -50%) rotate(0deg); }
    100% { transform: translate(-50%, -50%) rotate(360deg); }
}