Hide scroll bars when png rotates

Question

I am trying to rotate two png rings on a page. Everything is working except in Firefox scroll bars are appearing and moving up and down. I assume this is because of the square png rotating and bumping the edges.

Any ideas? CSS below:

@-webkit-keyframes rings {
    from {
        -webkit-transform: rotate(0deg);
    }
    to  { 
        -webkit-transform: rotate(359deg);
    }
}
@-moz-keyframes rings {
    from {
        -moz-transform: rotate(0deg);
    }
    to  { 
        -moz-transform: rotate(359deg);
    }
}
@-o-keyframes rings {
    from {
        -o-transform: rotate(0deg);
    }
    to  { 
        -o-transform: rotate(359deg);
    }
}
@keyframes rings {
    from {
        transform: rotate(0deg);
    }
    to  { 
        transform: rotate(359deg);
    }
}

.rotating-rings {
    position: absolute;
    z-index: -5;
    width: 90%;
    height: 90%;
    overflow: none;
}

#ring-1 {
    overflow: hidden;
    position: absolute;
    width: 90%;
    -webkit-animation-name: rings;
    -webkit-animation-duration: 9s;
    -webkit-animation-iteration-count: infinite;
    -webkit-animation-direction: normal;
    -webkit-transition-timing-function: linear;
    -moz-animation-name: rings;
    -moz-animation-duration: 9s;
    -moz-animation-iteration-count: infinite;
    -moz-animation-direction: normal;
    -moz-transition-timing-function: linear;
    -o-animation-name: rings;
    -o-animation-duration: 9s;
    -o-animation-iteration-count: infinite;
    -o-animation-direction: normal;
    -o-transition-timing-function: linear;
    animation-name: rings;
    animation-duration: 9s;
    animation-iteration-count: infinite;
    animation-direction: normal;
    transition-timing-function: linear;
}

#ring-2 {
    overflow: hidden;
    position: absolute;
    width: 90%;
    -webkit-animation-name: rings;
    -webkit-animation-duration: 10s;
    -webkit-animation-iteration-count: infinite;
    -webkit-animation-direction: reverse;
    -webkit-transition-timing-function: linear;
    -moz-animation-name: rings;
    -moz-animation-duration: 10s;
    -moz-animation-iteration-count: infinite;
    -moz-animation-direction: reverse;
    -moz-transition-timing-function: linear;
    -o-animation-name: rings;
    -o-animation-duration: 10s;
    -o-animation-iteration-count: infinite;
    -o-animation-direction: reverse;
    -o-transition-timing-function: linear;
    animation-name: rings;
    animation-duration: 10s;
    animation-iteration-count: infinite;
    animation-direction: reverse;
    transition-timing-function: linear;
}

Answer 1

Try applying overflow:hidden for the parent element of the image