diff --git a/src/styles/well_case.less b/src/styles/well_case.less
new file mode 100644
index 0000000..6f4975f
--- /dev/null
+++ b/src/styles/well_case.less
@@ -0,0 +1,31 @@
+.well-case-editor {
+    gap: 10px;
+    width: 100%;
+    max-height: 70vh;
+    display: flex;
+    align-items: stretch;
+    justify-content: space-between;
+
+    & .category-list {
+        display: flex;
+        flex-direction: column;
+        align-items: stretch;
+        justify-content: space-between;
+        gap: 10px;
+        width: 300px;
+    
+        & .category-list-item {
+            cursor: pointer;
+
+            &.empty {
+                background-color: #ffe58f;
+                border-color: #ffc53d;
+            }
+    
+            &.active {
+                background-color: #fafafa;
+                border: 1px solid #f0f0f0;
+            }
+        }
+    }
+}