refactor(styles): extract shared ProseMirror styles to reduce

duplication

scss/components/actor/_actor_properties.scss

@@ -26,7 +26,7 @@
 
   &__property-select {
     width: 100%;
-    height: var(--form-field-height);
+    height: var(--input-height);
   }
 
   &__property-multi-input {

scss/components/actor/_biography.scss

@@ -8,4 +8,10 @@
   display: grid;
   grid-template-columns: 1fr 3fr;
   column-gap: 1em;
+  height: 100%;
+}
+
+.ds4-biography {
+  height: 100%;
+  overflow: hidden;
 }

scss/components/shared/_editor.scss

@@ -16,3 +16,38 @@
     }
   }
 }
+
+// General ProseMirror editor styles
+prose-mirror {
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+  overflow: hidden;
+
+  // Edit mode with editor container
+  &.active {
+    .editor-container {
+      flex: 1;
+      display: flex;
+      flex-direction: column;
+      overflow: hidden;
+
+      .editor-content {
+        flex: 1;
+        overflow-y: auto;
+        min-height: 0;
+      }
+    }
+  }
+
+  // View mode - direct editor-content
+  &.inactive {
+    .editor-content {
+      position: relative;
+      flex: 1;
+      overflow-y: auto;
+      min-height: 0;
+      inset: auto;
+    }
+  }
+}

scss/components/shared/_form_group.scss

@@ -22,6 +22,6 @@
 
   &__label {
     flex: 2;
-    line-height: var(--form-field-height);
+    line-height: var(--input-height);
   }
 }

scss/components/shared/_sheet_body.scss

@@ -7,4 +7,9 @@
 .ds4-sheet-body {
   height: 100%;
   overflow-y: auto;
+
+  // Prevent double scrollbars on biography tab
+  .ds4-sheet-tab.tab.biography.active {
+    overflow: hidden;
+  }
 }