Add missing SCSS file for bergamot.

assets/scss/bergamot.scss

@@ -0,0 +1,44 @@
+@import "variables.scss";
+@import "mixins.scss";
+
+.bergamot-root {
+    @include bordered-block;
+    padding: 1em;
+
+    .bergamot-section-heading {
+        margin-bottom: 0.5em;
+        font-family: sans-serif;
+        font-weight: normal;
+    }
+
+    .bergamot-section {
+        margin-bottom: 1em;
+    }
+
+    textarea {
+        display: block;
+        width: 100%;
+        height: 10em;
+        resize: none;
+    }
+
+    input[type="text"] {
+        width: 100%;
+        @include textual-input;
+    }
+
+    .bergamot-rule-list {
+        display: flex;
+        flex-direction: row;
+        flex-wrap: wrap;
+        justify-content: center;
+    }
+
+    .bergamot-rule-list katex-expression {
+        margin-left: .5em;
+        margin-right: .5em;
+        flex-grow: 1;
+        flex-basis: 0;
+    }
+}
+