Rounding widget corners on two-thirds widgets

We’re currently running some custom code to round the corners of widgets. It’s working for all full-size widgets and one-third sized widgets. However, it’s not working for two-thirds widgets -- I’m trying to upload a two-thirds banner and the sharp corners starkly contrast with all the rounded corners. 

Here’s the CSS we’re currently using to round the corners:

/* Make all widgets border rounded*/
.pages-widget-page .single-widget *:not(.title):not(.ui-carousel-title):not(.ui-text-link):not(.ui-card-title):not(.ui-typography-heading-5):not(.subtitle) {
    border-radius: 10px;
}

Any thoughts?