Rust trial: port interface to Sycamore

Now we have a reactive web app written entirely in Rust. The Trunk build
tool compiles it to WebAssembly and generates a little JavaScript glue.

lang-trials/rust/main.css

@@ -0,0 +1,50 @@
+body {
+  margin-left: 20px;
+  margin-top: 20px;
+  color: #fcfcfc;
+  background-color: #202020;
+}
+
+input {
+  color: inherit;
+  background-color: #020202;
+  border: 1px solid #606060;
+  min-width: 40px;
+  border-radius: 4px;
+}
+
+input.point-1 {
+  border-color: #ba5d09;
+}
+
+input.point-2 {
+  border-color: #0e8a06;
+}
+
+input.point-3 {
+  border-color: #8951fb;
+}
+
+#data-panel {
+  float: left;
+  margin-left: 20px;
+  display: grid;
+  grid-template-columns: auto auto;
+  gap: 10px 10px;
+  width: 120px;
+}
+
+#data-panel > div {
+  text-align: center;
+}
+
+#result-display {
+  margin-top: 10px;
+  font-weight: bold;
+}
+
+canvas {
+  float: left;
+  background-color: #020202;
+  border-radius: 10px;
+}