I have a div block that simulates a small spinner, everything works fine however with the css configurations that I have it is positioned in the upper right wing, I tried to center it but when I see it from a mobile device it moves from place .. how could to center it without it changing position in devices with different sizes?
.spinner {
display: block;
position: fixed;
z-index: 1031;
top: 15px;
right: 15px;
}