Refactor a few selectors so that the least specific ones are first. (#24310)

scss/_card.scss

@@ -213,6 +213,10 @@
           }
         }
 
+        &:only-child {
+          @include border-radius($card-border-radius);
+        }
+
         &:not(:first-child):not(:last-child):not(:only-child) {
           border-radius: 0;
 
@@ -221,10 +225,6 @@
             border-radius: 0;
           }
         }
-
-        &:only-child {
-          @include border-radius($card-border-radius);
-        }
       }
     }
   }

scss/_dropdown.scss

@@ -9,19 +9,6 @@
   @include caret;
 }
 
-// Allow for dropdowns to go bottom up (aka, dropup-menu)
-// Just add .dropup after the standard .dropdown class and you're set.
-.dropup {
-  .dropdown-menu {
-    margin-top: 0;
-    margin-bottom: $dropdown-spacer;
-  }
-
-  .dropdown-toggle {
-    @include caret(up);
-  }
-}
-
 // The dropdown menu
 .dropdown-menu {
   position: absolute;
@@ -44,6 +31,19 @@
   @include box-shadow($dropdown-box-shadow);
 }
 
+// Allow for dropdowns to go bottom up (aka, dropup-menu)
+// Just add .dropup after the standard .dropdown class and you're set.
+.dropup {
+  .dropdown-menu {
+    margin-top: 0;
+    margin-bottom: $dropdown-spacer;
+  }
+
+  .dropdown-toggle {
+    @include caret(up);
+  }
+}
+
 // Dividers (basically an `<hr>`) within the dropdown
 .dropdown-divider {
   @include nav-divider($dropdown-divider-bg);

scss/_tooltip.scss

@@ -21,6 +21,12 @@
     height: $tooltip-arrow-height;
   }
 
+  .arrow::before {
+    position: absolute;
+    border-color: transparent;
+    border-style: solid;
+  }
+
   &.bs-tooltip-top {
     padding: $tooltip-arrow-width 0;
     .arrow {
@@ -88,12 +94,6 @@
       @extend .bs-tooltip-left;
     }
   }
-
-  .arrow::before {
-    position: absolute;
-    border-color: transparent;
-    border-style: solid;
-  }
 }
 
 // Wrapper for the tooltip content