UI/UX changes, added feature to switch to other LLM APIs

popup.css

@@ -128,16 +128,31 @@ select {
 }
 
 .button-row {
-  display: flex;
+  display: grid;
+  grid-template-columns: minmax(64px, 0.8fr) minmax(0, 1.4fr) minmax(64px, 0.8fr);
   gap: 8px;
 }
 
 .button-row button {
-  flex: 1;
+  white-space: nowrap;
 }
 
-.button-row .ghost {
-  flex: 0 0 64px;
+.button-row .primary {
+  padding: 6px 8px;
+}
+
+.stop-row {
+  display: flex;
+  justify-content: stretch;
+  margin-top: 4px;
+}
+
+.stop-row button {
+  width: 100%;
+}
+
+.hidden {
+  display: none;
 }
 
 button {
@@ -177,6 +192,12 @@ button:active {
   border: 1px solid var(--border);
 }
 
+.stop-row .ghost {
+  background: #c0392b;
+  border-color: #c0392b;
+  color: #fff6f2;
+}
+
 .meta {
   display: flex;
   justify-content: space-between;