Fix #9174: pad bottom of navbar collapsed content and clear floated contents

dist/css/bootstrap.css

@@ -2869,6 +2869,30 @@ button.close {
   margin-bottom: 0;
 }
 
+.nav-collapse {
+  padding-bottom: 15px;
+}
+
+.nav-collapse:before,
+.nav-collapse:after {
+  display: table;
+  content: " ";
+}
+
+.nav-collapse:after {
+  clear: both;
+}
+
+.nav-collapse:before,
+.nav-collapse:after {
+  display: table;
+  content: " ";
+}
+
+.nav-collapse:after {
+  clear: both;
+}
+
 @media (max-width: 768px) {
   .nav-collapse-scrollable {
     max-height: 360px;
@@ -3103,6 +3127,7 @@ button.close {
   .nav-collapse.collapse {
     display: block !important;
     height: auto !important;
+    padding-bottom: 0;
     overflow: visible !important;
   }
 }