Extract Grid Style 9 pseudo-element overlay with gradient

- Add :before pseudo-element with 70% height gradient overlay from transparent to black
- Include cross-browser gradient support (moz/webkit/o/ms) and IE filter fallback
- Position absolutely at bottom with z-index 1 for proper layering
- Apply .pp-content-post-grid parent scoping to prevent global conflicts

Author: pftg

themes/beaver/assets/css/utilities/components/powerpack/content-grid.css

@@ -254,4 +254,22 @@
   -ms-filter: "progid:DXImageTransform.Microsoft.Matrix(M11=1.1, M12=0, M21=0, M22=1.1, SizingMethod='auto expand')";
   filter: progid:DXImageTransform.Microsoft.Matrix(M11=1.1, M12=0, M21=0, M22=1.1, SizingMethod='auto expand');
   transform: scale(1.1);
+}
+
+/* Grid Style 9 Pseudo-element Overlay with Gradient */
+.pp-content-post-grid .pp-content-post.pp-grid-style-9 .pp-post-featured-img a:last-child:before {
+  content: "";
+  display: block;
+  height: 70%;
+  width: 100%;
+  position: absolute;
+  bottom: 0;
+  z-index: 1;
+  background: -moz-linear-gradient(top, rgba(0, 0, 0, 0) 40%, rgba(0, 0, 0, .7) 100%);
+  background: -webkit-gradient(linear, left top, left bottom, color-stop(40%, rgba(0, 0, 0, 0)), color-stop(100%, rgba(0, 0, 0, .7)));
+  background: -webkit-linear-gradient(top, rgba(0, 0, 0, 0) 40%, rgba(0, 0, 0, .7) 100%);
+  background: -o-linear-gradient(top, rgba(0, 0, 0, 0) 40%, rgba(0, 0, 0, .7) 100%);
+  background: -ms-linear-gradient(top, rgba(0, 0, 0, 0) 40%, rgba(0, 0, 0, .7) 100%);
+  background: linear-gradient(to bottom, rgba(0, 0, 0, 0) 40%, rgba(0, 0, 0, .7) 100%);
+  filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#00000000', endColorstr='#b3000000', GradientType=0);
 }