Fix UI issues, timer logic, theme switcher, view solutions, and markdown rendering

test4.js

@@ -0,0 +1,20 @@
+
+import("react-markdown").then(rm => {
+  import("remark-math").then(math => {
+    import("rehype-katex").then(katex => {
+      import("react-dom/server").then(rds => {
+        import("react").then(react => {
+          // This simulates string with actual backslash (e.g. from JSON parse)
+          const text = "Testing math $\\v(t) = \\int$ and $$\\alpha$$";
+          const el = react.createElement(rm.default, {
+            remarkPlugins: [math.default],
+            rehypePlugins: [katex.default],
+            children: text
+          });
+          console.log(rds.renderToString(el));
+        });
+      });
+    });
+  });
+})
+