Bug 1834973 IE11 side panels are at bottom of page

An issue with flex on IE11 where flex item has a max-width, the
fix sets the min-size in flex-basis to 0% instead of 25% so that
it grows to fit.

behatnotneeded

Change-Id: I719acbc6db578444d0621cb4f660cb2226d8960b

htdocs/theme/raw/sass/_custom.scss

@@ -877,3 +877,16 @@ a.online-users {
 .consentbutton span.description {
     padding: 0px !important;
 }
+
+// fixes ie11 flex issues making panels go to bottom of page
+@media screen and (-ms-high-contrast: active), (-ms-high-contrast: none) {
+  .col-lg-3 {
+      flex: 1 0 0%;
+      max-width: 25%;
+
+      @include media-breakpoint-down(md) {
+          flex: 1 0 0%;
+          max-width: 100%;
+      }
+  }
+}