<div class="css-loader"></div>
.css-loader {
    border: 16px solid #f3f3f3; 
    border-top: 16px solid blue; 
    border-radius: 50%;
    width: 100px;
    height: 100px;
    margin: auto;
    animation: spin 2s linear infinite;
}

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

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.