Logo scaling poor in IE11/Edge while fine in all other browsers

Hi Kriesi support team,

my site has a PNG logo with transparency. It scales well with all browsers except with IE11 / Edge. Seems it is about Microsofts image engine, and I tried to fix it using Quick CSS according to hints from this forum, but to no avail.

Currently I have in Quick CSS

#top .flex_column img {
    -ms-interpolation-mode: bicubic !important;
    image-rendering: optimizeQuality !important;
}

Probably my logo would scale best using SVG, but not all browsers support that, right? How to specify my logo in different resolutions using media queries I do not know. I am kind of lost, and would appreciate your help!