cat/resources/public/css/screen.css

html,
body {
	font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    height: 100%;
}

.loader-container {
    width: 700px;
    height: 425px;

    display: flex;
    justify-content: center;
    align-items: center;
}

.loader {
    border: 4px solid #f3f3f3; /* Light grey */
    border-top: 4px solid #3498db; /* Blue */
    border-radius: 50%; /*to make it a circle*/
    width: 60px;
    height: 60px;
    animation: spin 2s linear infinite;
}

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