feat: Adds hydronic system pressure calculator.

Sources/Styleguide/ResultBox.swift

@@ -0,0 +1,17 @@
+import Elementary
+
+public struct ResultBox<Body: HTML>: HTML {
+  let body: Body
+
+  public init(@HTMLBuilder body: () -> Body) {
+    self.body = body()
+  }
+
+  public var content: some HTML<HTMLTag.div> {
+    div(.class("w-full rounded-lg shadow-lg bg-blue-100 border border-blue-600 text-blue-600 p-6")) {
+      body
+    }
+  }
+}
+
+extension ResultBox: Sendable where Body: Sendable {}