.spinner {

    width: 400px;
    height: 400px;
    border: 8px solid rgba(0, 0, 0, 0.3);
    border-radius: 50%;
    border-left-color: #3D6A33;
    animation: spin 1s ease infinite;
    margin-left:15px;
    
}

.spinner {
    width: 100px;
    height: 100px;    
}

.contenedor {
    
    height:100vh;   

}

.divCentrado{
   
   width:30%;
   height:30%;
   position:absolute;
   top:45%;
   left:51%;
   margin-top:-100px;
   margin-left:-100px;
}

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

    100% {
        transform: rotate(360deg);
    }
}