typo in 8.x-2.0-beta9 version

Issue #3349742 by loopy1492, kerrymick, ultimike, dalemoore, keiserjb, steveoriol, afarsal, Amirez, thejimbirch, draenen, stacypendell, platinum1, yecmom, shobhit_juyal: "Unsupported operand types: string + int" error on multiple templates

Closes #3448314

css/bootstrap-paragraphs-accordion.css

@@ -12,17 +12,21 @@
   float: right;
 }
 /* Adds margin and padding to paragraphs in accordion section bodies. */
-.paragraph.paragraph--type--bp-accordion .panel-heading a {
+.paragraph.paragraph--type--bp-accordion .panel-heading button {
   display: block;
   padding: 10px 10px;
+  background: transparent;
+  border: 0;
+  width: 100%;
+  text-align: left;
 }
-.paragraph.paragraph--type--bp-accordion .panel-heading a:after {
+.paragraph.paragraph--type--bp-accordion .panel-heading button:after {
   float: right;
 }
-.paragraph.paragraph--type--bp-accordion .panel-heading a[aria-expanded="false"].display:after {
+.paragraph.paragraph--type--bp-accordion .panel-heading button[aria-expanded="false"].display:after {
   content: "+";
 }
-.paragraph.paragraph--type--bp-accordion .panel-heading a[aria-expanded="true"].display:after {
+.paragraph.paragraph--type--bp-accordion .panel-heading button[aria-expanded="true"].display:after {
   content: "-";
 }
 .paragraph.paragraph--type--bp-accordion .panel-collapse > .paragraph {