switch post previews to use flexbox, add better styling for cropped thumbnails

app/assets/stylesheets/common/main_layout.scss

@@ -38,12 +38,16 @@ div#page {
     }
 
     input[type=text] {
-      width: 10em;
-
       /* ensure expanded search box renders above post thumbnails. */
       z-index: 1;
       position: relative;
     }
+
+    button[type=submit] {
+      padding: 2px 6px;
+      background: #EEE;
+      border-left: none;
+    }
   }
 
   aside#sidebar > section {

app/assets/stylesheets/common/paginator.scss

@@ -10,11 +10,10 @@ div.paginator {
     a {
       margin: 0 0.25em;
       padding: 0.25em 0.75em;
-      border: 1px solid #EAEAEA;
     }
 
-    a.arrow {
-      border: none;
+    &.more {
+      color: grey;
     }
 
     a.arrow:hover {
@@ -22,10 +21,6 @@ div.paginator {
       color: $link_color;
     }
 
-    a.current {
-      border: 1px solid #AAA;
-    }
-
     a:hover {
       background: $link_color;
       color: white;