fix resize

index.html

@@ -332,7 +332,9 @@
     /* Always a single line: everything inside is sized in em, and
        fitFormula() in app.js lowers font-size when the line would overflow */
     .formula {
-        flex: 1;
+        /* Centered vertically in the card, but only as tall as its content,
+           so the term boxes do not stretch to the card height */
+        margin: auto 0;
         display: flex;
         align-items: center;
         flex-wrap: nowrap;