Ticket #23584: 23584.6.diff

wp-content/themes/twentythirteen/style.css

@@ -735 +735 @@
 }
 
 .wp-caption .wp-caption-text,
-.entry-caption {
+.entry-caption,
+.gallery-caption {
         color: #220e10;
         font-size: 18px;
         font-style: italic;
@@ -1251 +1252 @@
 .gallery-item {
         float: left;
         margin: 0 4px 4px 0;
+        overflow: hidden; 
+        position: relative;
 }
 
 .single .gallery-columns-1.gallery-size-medium,
@@ -1335 +1338 @@
 }
 
 .gallery-caption {
-        color: #777;
+        background-color: rgba(0, 0, 0, 0.7);
+        box-sizing: border-box;
+        color: #fff;
         font-size: 14px;
-        font-style: italic;
-        padding-top: 4px;
+        height: 74px;
+        line-height: 1.3;
+        margin: 0;
+        max-height: 100%;
+        opacity: 0;
+        padding: 2px 8px;
+        position: absolute;
+        bottom: 0;
+        left: 0;
+        text-align: left;
+        -webkit-transition: opacity 400ms ease; 
+        transition:         opacity 400ms ease;
+        width: 100%;
 }
 
-.gallery-caption {
-        width: 90%;
+.gallery-caption:before {
+        box-shadow: 0 -10px 15px #000 inset;
+        content: "";
+        height: 74px;
+        position: absolute;
+        bottom: 0;
+        left: 0;
+        width: 100%;
 }
 
+.gallery-item:hover .gallery-caption {
+        opacity: 1;
+}
 
 /**
  * 5.6 Post Formats