qwc2/components/widgets/style/FileSelector.css

QGIS Web Client

div.FileSelector {
    display: inline-flex;
    position: relative;
    cursor: pointer;
    overflow-x: hidden;
}

div.FileSelector > input[type=text] {
    flex: 1 1 auto;
}

div.FileSelector > input[type=file] {
    display: none;
}