shadow editor now can handle expressions (functions and variables)

src/components/shadow_control/shadow_control.scss

@@ -4,6 +4,7 @@
   justify-content: stretch;
   grid-gap: 0.25em;
   margin-bottom: 1em;
+  width: 100%;
 
   .shadow-switcher {
     order: 1;
@@ -37,6 +38,9 @@
     min-width: 10em;
     margin-left: 0.125em;
     margin-right: 0.125em;
+    display: grid;
+    grid-template-rows: auto 1fr;
+    grid-gap: 0.25em;
 
     /* hack */
     .input-boolean {
@@ -52,6 +56,11 @@
       flex: 1 0 5em;
     }
 
+    .shadow-expression {
+      width: 100%;
+      height: 100%;
+    }
+
     .id-control {
       align-items: stretch;
 
@@ -100,6 +109,5 @@
 }
 
 .inset-tooltip {
-  padding: 0.5em;
   max-width: 30em;
 }