Add wasm-mutator-fuzz test (#3420)

tests/fuzz/wasm-mutator-fuzz/portal/src/App.css

@@ -0,0 +1,50 @@
+#root {
+  background-color: rgba(230, 240, 240, 0.9);
+  max-width: 100%;
+  height: 100%;
+  margin: 0 auto;
+  padding: 2rem;
+  text-align: center;
+}
+
+.logo {
+  height: 6em;
+  padding: 1.5em;
+  will-change: filter;
+}
+.logo:hover {
+  filter: drop-shadow(0 0 2em #646cffaa);
+}
+.logo.react:hover {
+  filter: drop-shadow(0 0 2em #61dafbaa);
+}
+
+@keyframes logo-spin {
+  from {
+    transform: rotate(0deg);
+  }
+  to {
+    transform: rotate(360deg);
+  }
+}
+
+@media (prefers-reduced-motion: no-preference) {
+  a:nth-of-type(2) .logo {
+    animation: logo-spin infinite 20s linear;
+  }
+}
+
+.card {
+  padding: 2em;
+}
+
+.read-the-docs {
+  color: #888;
+}
+
+.col-item-value {
+  overflow: hidden;
+  line-height: 35px;
+  white-space: nowrap;
+  text-overflow: ellipsis;
+}