diff --git a/gui/package.json b/gui/package.json
index 20a2fcbf..08082a12 100644
--- a/gui/package.json
+++ b/gui/package.json
@@ -23,10 +23,9 @@
     "@emotion/react": "^11.11.4",
     "@emotion/styled": "^11.11.5",
     "@fi-sci/misc": "^0.0.8",
-    "@fi-sci/modal-window": "^0.0.2",
     "@geoffcox/react-splitter": "^2.1.2",
     "@monaco-editor/react": "^4.6.0",
-    "@mui/icons-material": "^5.15.17",
+    "@mui/icons-material": "^5.16.5",
     "@mui/material": "^5.15.17",
     "@octokit/rest": "^21.0.0",
     "@vercel/analytics": "^1.3.1",
diff --git a/gui/src/app/App.tsx b/gui/src/app/App.tsx
index e7673069..7899515e 100644
--- a/gui/src/app/App.tsx
+++ b/gui/src/app/App.tsx
@@ -1,17 +1,23 @@
-import { BrowserRouter } from "react-router-dom";
+import { createTheme } from "@mui/material";
+import { ThemeProvider } from "@mui/system";
 import ProjectContextProvider from "@SpCore/ProjectContextProvider";
 import HomePage from "@SpPages/HomePage";
 import { Analytics } from "@vercel/analytics/react";
+import { BrowserRouter } from "react-router-dom";
+
+const theme = createTheme();
 
 function App() {
   return (
     <BrowserRouter>
-      <div className="MainWindow">
-        <ProjectContextProvider>
-          <HomePage />
-        </ProjectContextProvider>
-        <Analytics />
-      </div>
+      <ThemeProvider theme={theme}>
+        <div className="MainWindow">
+          <ProjectContextProvider>
+            <HomePage />
+          </ProjectContextProvider>
+          <Analytics />
+        </div>
+      </ThemeProvider>
     </BrowserRouter>
   );
 }
diff --git a/gui/src/app/CompilationServerConnectionControl/CompilationServerConnectionControl.tsx b/gui/src/app/CompilationServerConnectionControl/CompilationServerConnectionControl.tsx
index 9c73ff23..175878a1 100644
--- a/gui/src/app/CompilationServerConnectionControl/CompilationServerConnectionControl.tsx
+++ b/gui/src/app/CompilationServerConnectionControl/CompilationServerConnectionControl.tsx
@@ -1,17 +1,20 @@
 import { SmallIconButton } from "@fi-sci/misc";
-import { default as ModalWindow, useModalWindow } from "@fi-sci/modal-window";
 import { Cancel, Check } from "@mui/icons-material";
-import Button from "@mui/material/Button";
 import Link from "@mui/material/Link";
+
+import CloseableDialog, {
+  useDialogControls,
+} from "@SpComponents/CloseableDialog";
 import { FunctionComponent, useCallback, useEffect, useState } from "react";
+import ConfigureCompilationServerDialog from "./ConfigureCompilationServerDialog";
+
+export const publicUrl = "https://trom-stan-wasm-server.magland.org";
+export const localUrl = "http://localhost:8083";
 
 type CompilationServerConnectionControlProps = {
   // none
 };
 
-const publicUrl = "https://trom-stan-wasm-server.magland.org";
-const localUrl = "http://localhost:8083";
-
 const CompilationServerConnectionControl: FunctionComponent<
   CompilationServerConnectionControlProps
 > = () => {
@@ -26,8 +29,8 @@ const CompilationServerConnectionControl: FunctionComponent<
   const {
     handleOpen: openDialog,
     handleClose: closeDialog,
-    visible: dialogVisible,
-  } = useModalWindow();
+    open,
+  } = useDialogControls();
 
   const handleRetry = useCallback(() => {
     retryConnection();
@@ -60,7 +63,12 @@ const CompilationServerConnectionControl: FunctionComponent<
         </Link>
         &nbsp;&nbsp;
       </span>
-      <ModalWindow visible={dialogVisible} onClose={closeDialog}>
+      <CloseableDialog
+        title="Select a compilation server"
+        id="compilationDialog"
+        open={open}
+        handleClose={closeDialog}
+      >
         <ConfigureCompilationServerDialog
           stanWasmServerUrl={stanWasmServerUrl}
           setStanWasmServerUrl={setStanWasmServerUrl}
@@ -68,7 +76,7 @@ const CompilationServerConnectionControl: FunctionComponent<
           closeDialog={closeDialog}
           onRetry={handleRetry}
         />
-      </ModalWindow>
+      </CloseableDialog>
     </span>
   );
 };
@@ -96,123 +104,4 @@ const useIsConnected = (stanWasmServerUrl: string) => {
   return { isConnected, retryConnection };
 };
 
-type ConfigureCompilationServerDialogProps = {
-  stanWasmServerUrl: string;
-  setStanWasmServerUrl: (url: string) => void;
-  isConnected: boolean;
-  closeDialog: () => void;
-  onRetry: () => void;
-};
-
-const ConfigureCompilationServerDialog: FunctionComponent<
-  ConfigureCompilationServerDialogProps
-> = ({
-  stanWasmServerUrl,
-  setStanWasmServerUrl,
-  isConnected,
-  closeDialog,
-  onRetry,
-}) => {
-  const [choice, setChoice] = useState<"public" | "local" | "custom">("custom");
-  useEffect(() => {
-    if (stanWasmServerUrl === publicUrl) setChoice("public");
-    else if (stanWasmServerUrl === localUrl) setChoice("local");
-    else setChoice("custom");
-  }, [stanWasmServerUrl]);
-  return (
-    <div>
-      <h3>Select a compilation server</h3>
-      <p>
-        While the sampling is performed locally in the browser, a compilation
-        server is required to compile the Stan programs.
-      </p>
-      <hr />
-      <div>
-        {isConnected ? (
-          <span className="connected">Connected</span>
-        ) : (
-          <span className="disconnected">Not connected</span>
-        )}
-        &nbsp;
-        <Link onClick={onRetry} component="button" underline="none">
-          retry
-        </Link>
-      </div>
-      <hr />
-      <div>
-        <input
-          type="radio"
-          id="public"
-          name="server"
-          value="public"
-          checked={choice === "public"}
-          onChange={() => {
-            if (choice === "custom") setChoice("public");
-            setStanWasmServerUrl(publicUrl);
-          }}
-        />
-        <label htmlFor="public">Public server</label>
-        <br />
-
-        <input
-          type="radio"
-          id="local"
-          name="server"
-          value="local"
-          checked={choice === "local"}
-          onChange={() => {
-            if (choice === "custom") setChoice("local");
-            setStanWasmServerUrl(localUrl);
-          }}
-        />
-        <label htmlFor="local">Local server</label>
-        <br />
-
-        <input
-          type="radio"
-          id="custom"
-          name="server"
-          value="custom"
-          checked={choice === "custom"}
-          onChange={() => setChoice("custom")}
-        />
-        <label htmlFor="custom">Custom server</label>
-        <br />
-
-        <input
-          // This one isn't honoring a class-based style for some reason
-          style={{ width: 500 }}
-          disabled={choice !== "custom"}
-          type="text"
-          value={stanWasmServerUrl}
-          onChange={(e) => setStanWasmServerUrl(e.target.value)}
-        />
-        <br />
-        <hr />
-        {choice === "local" && (
-          <div>
-            <p>To start a local compilation server:</p>
-            <div>
-              <pre>
-                docker run -p 8083:8080 -it magland/stan-wasm-server:latest
-              </pre>
-            </div>
-          </div>
-        )}
-        {choice === "public" && (
-          <div>
-            <p>
-              The public server is provided for convenience, but may not be as
-              reliable as a local server, depending on the current load and
-              availability.
-            </p>
-          </div>
-        )}
-        <hr />
-        <Button onClick={() => closeDialog()}>Close</Button>
-      </div>
-    </div>
-  );
-};
-
 export default CompilationServerConnectionControl;
diff --git a/gui/src/app/CompilationServerConnectionControl/ConfigureCompilationServerDialog.tsx b/gui/src/app/CompilationServerConnectionControl/ConfigureCompilationServerDialog.tsx
new file mode 100644
index 00000000..b953c5a0
--- /dev/null
+++ b/gui/src/app/CompilationServerConnectionControl/ConfigureCompilationServerDialog.tsx
@@ -0,0 +1,124 @@
+import Button from "@mui/material/Button";
+import Link from "@mui/material/Link";
+import { FunctionComponent, useEffect, useState } from "react";
+import { localUrl, publicUrl } from "./CompilationServerConnectionControl";
+
+type ConfigureCompilationServerDialogProps = {
+  stanWasmServerUrl: string;
+  setStanWasmServerUrl: (url: string) => void;
+  isConnected: boolean;
+  closeDialog: () => void;
+  onRetry: () => void;
+};
+
+const ConfigureCompilationServerDialog: FunctionComponent<
+  ConfigureCompilationServerDialogProps
+> = ({
+  stanWasmServerUrl,
+  setStanWasmServerUrl,
+  isConnected,
+  closeDialog,
+  onRetry,
+}) => {
+  const [choice, setChoice] = useState<"public" | "local" | "custom">("custom");
+  useEffect(() => {
+    if (stanWasmServerUrl === publicUrl) setChoice("public");
+    else if (stanWasmServerUrl === localUrl) setChoice("local");
+    else setChoice("custom");
+  }, [stanWasmServerUrl]);
+  return (
+    <div className="dialogWrapper">
+      <p>
+        While the sampling is performed locally in the browser, a compilation
+        server is required to compile the Stan programs.
+      </p>
+      <hr />
+      <div>
+        {isConnected ? (
+          <span className="connected">Connected</span>
+        ) : (
+          <span className="disconnected">Not connected</span>
+        )}
+        &nbsp;
+        <Link onClick={onRetry} component="button" underline="none">
+          retry
+        </Link>
+      </div>
+      <hr />
+      <div>
+        <input
+          type="radio"
+          id="public"
+          name="server"
+          value="public"
+          checked={choice === "public"}
+          onChange={() => {
+            if (choice === "custom") setChoice("public");
+            setStanWasmServerUrl(publicUrl);
+          }}
+        />
+        <label htmlFor="public">Public server</label>
+        <br />
+
+        <input
+          type="radio"
+          id="local"
+          name="server"
+          value="local"
+          checked={choice === "local"}
+          onChange={() => {
+            if (choice === "custom") setChoice("local");
+            setStanWasmServerUrl(localUrl);
+          }}
+        />
+        <label htmlFor="local">Local server</label>
+        <br />
+
+        <input
+          type="radio"
+          id="custom"
+          name="server"
+          value="custom"
+          checked={choice === "custom"}
+          onChange={() => setChoice("custom")}
+        />
+        <label htmlFor="custom">Custom server</label>
+        <br />
+
+        <input
+          // This one isn't honoring a class-based style for some reason
+          style={{ width: 500 }}
+          disabled={choice !== "custom"}
+          type="text"
+          value={stanWasmServerUrl}
+          onChange={(e) => setStanWasmServerUrl(e.target.value)}
+        />
+        <br />
+        <hr />
+        {choice === "local" && (
+          <div>
+            <p>To start a local compilation server:</p>
+            <div>
+              <pre>
+                docker run -p 8083:8080 -it magland/stan-wasm-server:latest
+              </pre>
+            </div>
+          </div>
+        )}
+        {choice === "public" && (
+          <div>
+            <p>
+              The public server is provided for convenience, but may not be as
+              reliable as a local server, depending on the current load and
+              availability.
+            </p>
+          </div>
+        )}
+        <hr />
+        <Button onClick={() => closeDialog()}>Close</Button>
+      </div>
+    </div>
+  );
+};
+
+export default ConfigureCompilationServerDialog;
diff --git a/gui/src/app/components/CloseableDialog.tsx b/gui/src/app/components/CloseableDialog.tsx
new file mode 100644
index 00000000..e364a017
--- /dev/null
+++ b/gui/src/app/components/CloseableDialog.tsx
@@ -0,0 +1,56 @@
+import CloseIcon from "@mui/icons-material/Close";
+import Dialog from "@mui/material/Dialog";
+import DialogTitle from "@mui/material/DialogTitle";
+import IconButton from "@mui/material/IconButton";
+import { FunctionComponent, PropsWithChildren, useState } from "react";
+
+type CloseableDialogProps = {
+  title: string;
+  id: string;
+  open: boolean;
+  handleClose: () => void;
+};
+
+export const useDialogControls = () => {
+  const [open, setOpen] = useState(false);
+
+  const handleOpen = () => {
+    setOpen(true);
+  };
+  const handleClose = () => {
+    setOpen(false);
+  };
+
+  return { open, handleOpen, handleClose };
+};
+
+const CloseableDialog: FunctionComponent<
+  PropsWithChildren<CloseableDialogProps>
+> = ({ title, id, handleClose, open, children }) => {
+  const theDialog = (
+    <Dialog
+      onClose={handleClose}
+      aria-labelledby={`customized-dialog-title-${id}`}
+      open={open}
+    >
+      <DialogTitle id={`customized-dialog-title-${id}`}>{title}</DialogTitle>
+      <IconButton
+        aria-label="close"
+        onClick={handleClose}
+        sx={{
+          position: "absolute",
+          right: 8,
+          top: 8,
+          color: (theme) => theme.palette.grey[500],
+        }}
+      >
+        <CloseIcon />
+      </IconButton>
+      {children}
+    </Dialog>
+  );
+
+  return theDialog;
+};
+
+export default CloseableDialog;
diff --git a/gui/src/app/pages/HomePage/LoadProjectWindow.tsx b/gui/src/app/pages/HomePage/LoadProjectWindow.tsx
index 27706868..a9718367 100644
--- a/gui/src/app/pages/HomePage/LoadProjectWindow.tsx
+++ b/gui/src/app/pages/HomePage/LoadProjectWindow.tsx
@@ -104,8 +104,7 @@ const LoadProjectWindow: FunctionComponent<LoadProjectWindowProps> = ({
   }, [filesUploaded, importUploadedFiles]);
 
   return (
-    <div>
-      <h3>Load project</h3>
+    <div className="dialogWrapper">
       <div>
         You can upload:
         <ul>
diff --git a/gui/src/app/pages/HomePage/SaveProjectWindow.tsx b/gui/src/app/pages/HomePage/SaveProjectWindow.tsx
index 42dcd0d4..32570d47 100644
--- a/gui/src/app/pages/HomePage/SaveProjectWindow.tsx
+++ b/gui/src/app/pages/HomePage/SaveProjectWindow.tsx
@@ -1,8 +1,8 @@
 import { FunctionComponent, useCallback, useContext, useState } from "react";
 
-import { serializeAsZip } from "@SpCore/ProjectSerialization";
 import { FileRegistry, mapModelToFileManifest } from "@SpCore/FileMapping";
 import { ProjectContext } from "@SpCore/ProjectContextProvider";
+import { serializeAsZip } from "@SpCore/ProjectSerialization";
 import saveAsGitHubGist from "@SpCore/gists/saveAsGitHubGist";
 import { triggerDownload } from "@SpUtil/triggerDownload";
 import Button from "@mui/material/Button";
@@ -20,8 +20,7 @@ const SaveProjectWindow: FunctionComponent<SaveProjectWindowProps> = ({
   const [exportingToGist, setExportingToGist] = useState(false);
 
   return (
-    <div>
-      <h3>Save this project</h3>
+    <div className="dialogWrapper">
       <table className="project-summary-table">
         <tbody>
           <tr>
diff --git a/gui/src/app/pages/HomePage/Sidebar.tsx b/gui/src/app/pages/HomePage/Sidebar.tsx
index b7d63bc3..eceeb4b7 100644
--- a/gui/src/app/pages/HomePage/Sidebar.tsx
+++ b/gui/src/app/pages/HomePage/Sidebar.tsx
@@ -1,14 +1,15 @@
+import CloseableDialog, {
+  useDialogControls,
+} from "@SpComponents/CloseableDialog";
 import { ProjectContext } from "@SpCore/ProjectContextProvider";
 import { modelHasUnsavedChanges } from "@SpCore/ProjectDataModel";
 import LoadProjectWindow from "@SpPages/LoadProjectWindow";
 import SaveProjectWindow from "@SpPages/SaveProjectWindow";
-import ModalWindow, { useModalWindow } from "@fi-sci/modal-window";
+import { List, ListItem } from "@mui/material";
 import Button from "@mui/material/Button";
 import Divider from "@mui/material/Divider";
 import Drawer from "@mui/material/Drawer";
 import Link from "@mui/material/Link";
-import List from "@mui/material/List";
-import ListItem from "@mui/material/ListItem";
 import Toolbar from "@mui/material/Toolbar";
 import { FunctionComponent, useContext, useMemo } from "react";
 import { useNavigate } from "react-router-dom";
@@ -43,15 +44,15 @@ const Sidebar: FunctionComponent<Sidebar> = ({
   const dataModified = useMemo(() => modelHasUnsavedChanges(data), [data]);
 
   const {
-    visible: saveProjectVisible,
+    open: saveProjectVisible,
     handleOpen: saveProjectOpen,
     handleClose: saveProjectClose,
-  } = useModalWindow();
+  } = useDialogControls();
   const {
-    visible: loadProjectVisible,
+    open: loadProjectVisible,
     handleOpen: loadProjectOpen,
     handleClose: loadProjectClose,
-  } = useModalWindow();
+  } = useDialogControls();
 
   return (
     <Drawer
@@ -136,12 +137,22 @@ const Sidebar: FunctionComponent<Sidebar> = ({
         </List>
       </div>
 
-      <ModalWindow visible={loadProjectVisible} onClose={loadProjectClose}>
+      <CloseableDialog
+        title="Load Project"
+        id="loadProjectDialog"
+        open={loadProjectVisible}
+        handleClose={loadProjectClose}
+      >
         <LoadProjectWindow onClose={loadProjectClose} />
-      </ModalWindow>
-      <ModalWindow visible={saveProjectVisible} onClose={saveProjectClose}>
+      </CloseableDialog>
+      <CloseableDialog
+        title="Save this project"
+        id="saveProjectDialog"
+        open={saveProjectVisible}
+        handleClose={saveProjectClose}
+      >
         <SaveProjectWindow onClose={saveProjectClose} />
-      </ModalWindow>
+      </CloseableDialog>
     </Drawer>
   );
 };
diff --git a/gui/src/localStyles.css b/gui/src/localStyles.css
index 993e6aa6..435a10bf 100644
--- a/gui/src/localStyles.css
+++ b/gui/src/localStyles.css
@@ -13,6 +13,10 @@
   color: red;
 }
 
+.dialogWrapper {
+  padding: 10px;
+}
+
 .CompilationServerConnectionPane {
   font-size: 12px;
 }
diff --git a/gui/yarn.lock b/gui/yarn.lock
index d923faec..9ae49ff6 100644
--- a/gui/yarn.lock
+++ b/gui/yarn.lock
@@ -554,14 +554,6 @@
   resolved "https://registry.yarnpkg.com/@fi-sci/misc/-/misc-0.0.8.tgz#56b0c5402fc64df873c8a7b0d65966c3df3f0dd7"
   integrity sha512-lhbKCriIv9TxBw3xSZ/q7mlfVDc+OsJ1x6jesyeHEVMdqqYHDIRTZTdUIrnA0jdL4nMj3FbYNHE49Z7K+iouiQ==
 
-"@fi-sci/modal-window@^0.0.2":
-  version "0.0.2"
-  resolved "https://registry.yarnpkg.com/@fi-sci/modal-window/-/modal-window-0.0.2.tgz#ab50fe92925a2efd01fd8d3ab54f8f47bf7821b3"
-  integrity sha512-CHeCWWLblUNUtqCWIhnR6+2TYzzcoJlKj0PGgnw5XYEOFHhV7TBDGFQ5jzc609jAPRfc3grkUYJy6lru+BnFWA==
-  dependencies:
-    "@mui/icons-material" "^5.14.19"
-    "@mui/material" "^5.14.20"
-
 "@floating-ui/core@^1.6.0":
   version "1.6.4"
   resolved "https://registry.yarnpkg.com/@floating-ui/core/-/core-1.6.4.tgz#0140cf5091c8dee602bff9da5ab330840ff91df6"
@@ -715,14 +707,14 @@
   resolved "https://registry.yarnpkg.com/@mui/core-downloads-tracker/-/core-downloads-tracker-5.15.21.tgz#15ffc56cef7009479229b55126176f988afba96b"
   integrity sha512-dp9lXBaJZzJYeJfQY3Ow4Rb49QaCEdkl2KKYscdQHQm6bMJ+l4XPY3Cd9PCeeJTsHPIDJ60lzXbeRgs6sx/rpw==
 
-"@mui/icons-material@^5.14.19", "@mui/icons-material@^5.15.17":
-  version "5.15.21"
-  resolved "https://registry.yarnpkg.com/@mui/icons-material/-/icons-material-5.15.21.tgz#1e29e1bdb90916be5b66c95c45951f441821f34a"
-  integrity sha512-yqkq1MbdkmX5ZHyvZTBuAaA6RkvoqkoAgwBSx9Oh0L0jAfj9T/Ih/NhMNjkl8PWVSonjfDUkKroBnjRyo/1M9Q==
+"@mui/icons-material@^5.16.5":
+  version "5.16.5"
+  resolved "https://registry.yarnpkg.com/@mui/icons-material/-/icons-material-5.16.5.tgz#53cdd03132315c8daff2200d146035f34c913470"
+  integrity sha512-bn88xxU/J9UV0s6+eutq7o3TTOrOlbCX+KshFb8kxgIxJZZfYz3JbAXVMivvoMF4Md6jCVUzM9HEkf4Ajab4tw==
   dependencies:
     "@babel/runtime" "^7.23.9"
 
-"@mui/material@^5.14.20", "@mui/material@^5.15.17":
+"@mui/material@^5.15.17":
   version "5.15.21"
   resolved "https://registry.yarnpkg.com/@mui/material/-/material-5.15.21.tgz#b2c8d756af570a61cb4975acf0e71dafb110b001"
   integrity sha512-nTyCcgduKwHqiuQ/B03EQUa+utSMzn2sQp0QAibsnYe4tvc3zkMbO0amKpl48vhABIY3IvT6w9615BFIgMt0YA==