diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..d2aaff0
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1684428141,
+        "narHash": "sha256-yaMyF02+Wr4H9NQc0HDxQTUon8yqU0GrSzeDlnc1N3M=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "edcd3d30564ca6d4c1f2442c4149fa908228243e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..b3a6968
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,31 @@
+{
+  description = "JavaScript development environment";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs";
+  };
+
+  outputs = { self, nixpkgs }:
+    let
+      # Systems supported
+      allSystems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+      
+      forAllSystems = f: nixpkgs.lib.genAttrs allSystems (system: f {
+        pkgs = nixpkgs.legacyPackages.${system};
+      });
+    in
+    {
+      devShells = forAllSystems ({ pkgs }: {
+        default = pkgs.mkShell {
+          packages = with pkgs; [
+            nodejs # Node.js, plus npm, npx, and corepack
+          ];
+        };
+      });
+    };
+}
diff --git a/src/components/ArticleSearchWrapper.astro b/src/components/ArticleSearchWrapper.astro
index bfabbb5..d6a2f40 100644
--- a/src/components/ArticleSearchWrapper.astro
+++ b/src/components/ArticleSearchWrapper.astro
@@ -7,4 +7,4 @@ const articles = (await getCollection("blog")).sort(
 );
 ---
 
-<ArticleSearch client:load {articles} />
+<ArticleSearch client:only="svelte" {articles} />
diff --git a/src/components/Dropdown.svelte b/src/components/Dropdown.svelte
index 2b948ba..d1b60be 100644
--- a/src/components/Dropdown.svelte
+++ b/src/components/Dropdown.svelte
@@ -1,7 +1,7 @@
 <script lang="ts">
     export let shortcut: string;
 
-    const possibleShortcuts = ["S", "T"];
+    const possibleShortcuts = ["S", "C", "T"];
 
     let detailsElement: HTMLDetailsElement;
     let summaryElement: HTMLElement;
diff --git a/src/components/Head.astro b/src/components/Head.astro
index ebd6c60..02d6d70 100644
--- a/src/components/Head.astro
+++ b/src/components/Head.astro
@@ -11,4 +11,8 @@ const { title, description } = Astro.props;
   <title>{title}</title>
   <meta name="author" content="Your Name" />
   <meta name="description" content={description} />
+  <script is:inline>
+    const storedTheme = localStorage.getItem("theme");
+    document.documentElement.classList = storedTheme;
+  </script>
 </head>
diff --git a/src/components/Nav.astro b/src/components/Nav.astro
index cda1920..3179d09 100644
--- a/src/components/Nav.astro
+++ b/src/components/Nav.astro
@@ -1,5 +1,6 @@
 ---
 import ArticleSearchWrapper from "../components/ArticleSearchWrapper.astro";
+import ThemeToggle from "../components/ThemeToggle.svelte";
 ---
 
 <nav>
@@ -9,6 +10,7 @@ import ArticleSearchWrapper from "../components/ArticleSearchWrapper.astro";
     </a>
     <slot />
     <ArticleSearchWrapper />
+    <ThemeToggle client:only="svelte" />
   </div>
 </nav>
 
diff --git a/src/components/TableOfContents.svelte b/src/components/TableOfContents.svelte
index afcba35..99659bb 100644
--- a/src/components/TableOfContents.svelte
+++ b/src/components/TableOfContents.svelte
@@ -4,19 +4,17 @@
     export let headings: MarkdownHeading[] = [];
 
     import Dropdown from "./Dropdown.svelte";
-
-    let dropdown;
 </script>
 
-<Dropdown shortcut="T" bind:this={dropdown}>
+<Dropdown shortcut="C">
     <svg slot="icon" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor">
-      <title>Table of contents (Shift + t)</title>
+      <title>Table of contents (Shift + c)</title>
       <path fill-rule="evenodd" d="M2.625 6.75a1.125 1.125 0 112.25 0 1.125 1.125 0 01-2.25 0zm4.875 0A.75.75 0 018.25 6h12a.75.75 0 010 1.5h-12a.75.75 0 01-.75-.75zM2.625 12a1.125 1.125 0 112.25 0 1.125 1.125 0 01-2.25 0zM7.5 12a.75.75 0 01.75-.75h12a.75.75 0 010 1.5h-12A.75.75 0 017.5 12zm-4.875 5.25a1.125 1.125 0 112.25 0 1.125 1.125 0 01-2.25 0zm4.875 0a.75.75 0 01.75-.75h12a.75.75 0 010 1.5h-12a.75.75 0 01-.75-.75z" clip-rule="evenodd" />
     </svg>
     <ul>
         {#each headings.filter(({ depth }) => depth === 2) as { slug, text }}
             <li>
-                <a href="#{slug}" on:click={dropdown.closeMenu}>{text}</a>
+                <a href="#{slug}">{text}</a>
             </li>
         {/each}
     </ul>
diff --git a/src/components/ThemeToggle.svelte b/src/components/ThemeToggle.svelte
new file mode 100644
index 0000000..40edc70
--- /dev/null
+++ b/src/components/ThemeToggle.svelte
@@ -0,0 +1,47 @@
+<script lang="ts">
+  import Dropdown from "./Dropdown.svelte";
+
+  let themeOptions = ["System", "Light", "Dark"];
+
+  let theme = "System";
+
+  function loadTheme() {
+    theme = localStorage.getItem("theme");
+  }
+
+  function saveTheme() {
+    localStorage.setItem("theme", theme);
+  }
+
+  loadTheme();
+
+  $: document.documentElement.classList = theme;
+</script>
+
+<Dropdown shortcut="T">
+  <svg slot="icon" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor" class="w-6 h-6">
+    <title>Toggle theme (Shift + t)</title>
+    <path fill-rule="evenodd" d="M2.25 5.25a3 3 0 013-3h13.5a3 3 0 013 3V15a3 3 0 01-3 3h-3v.257c0 .597.237 1.17.659 1.591l.621.622a.75.75 0 01-.53 1.28h-9a.75.75 0 01-.53-1.28l.621-.622a2.25 2.25 0 00.659-1.59V18h-3a3 3 0 01-3-3V5.25zm1.5 0v7.5a1.5 1.5 0 001.5 1.5h13.5a1.5 1.5 0 001.5-1.5v-7.5a1.5 1.5 0 00-1.5-1.5H5.25a1.5 1.5 0 00-1.5 1.5z" clip-rule="evenodd" />
+  </svg>
+  <div class="theme-toggle">
+    {#each themeOptions as option, index}
+      <div>
+        <input type="radio" id="theme-{option}" name="theme" value={option} bind:group={theme} on:change={saveTheme} />
+        <label for="theme-{option}">{option}</label>
+      </div>
+    {/each}
+  </div>
+</Dropdown>
+
+<style>
+  .theme-toggle {
+    position: absolute;
+    inset-inline-end: 0;
+    inset-block-start: var(--nav-height);
+    background-color: var(--background-color);
+    border: var(--standard-border);
+    padding: 1rem;
+    display: grid;
+    gap: 0.5rem;
+  }
+</style>
\ No newline at end of file
diff --git a/src/layouts/ArticleLayout.astro b/src/layouts/ArticleLayout.astro
index ec0587e..6d2312a 100644
--- a/src/layouts/ArticleLayout.astro
+++ b/src/layouts/ArticleLayout.astro
@@ -7,7 +7,7 @@ import PublicationDate from "../components/PublicationDate.astro";
 ---
 
 <PageLayout {title} {description}>
-  <TableOfContents slot="nav" client:load {headings} />
+  <TableOfContents slot="nav" client:only="svelte" {headings} />
   <Fragment slot="header">
     <p>
       Published on
diff --git a/src/pages/index.astro b/src/pages/index.astro
index 57bf4cf..c7bd350 100644
--- a/src/pages/index.astro
+++ b/src/pages/index.astro
@@ -13,7 +13,7 @@ const articles = (await getCollection("blog")).sort(
 ---
 
 <PageLayout {...home.data}>
-  <TableOfContents slot="nav" client:load {headings} />
+  <TableOfContents slot="nav" client:only="svelte" {headings} />
   <Content />
   {
     articles.map((article) => (
diff --git a/src/styles/global.css b/src/styles/global.css
index 527607b..8b48d0c 100644
--- a/src/styles/global.css
+++ b/src/styles/global.css
@@ -6,6 +6,8 @@
   --tertiary-background-color: hsl(0 0% 90%);
   --text-color: hsl(0 0% 10%);
   --accent-color: #1e40af;
+
+  color-scheme: light;
 }
 
 @media (prefers-color-scheme: dark) {
@@ -20,6 +22,26 @@
   }
 }
 
+html.Light {
+  --background-color: hsl(0 0% 100%);
+  --secondary-background-color: hsl(0 0% 95%);
+  --tertiary-background-color: hsl(0 0% 90%);
+  --text-color: hsl(0 0% 10%);
+  --accent-color: #1e40af;
+
+  color-scheme: light;
+}
+
+html.Dark {
+  --background-color: hsl(0 0% 10%);
+  --secondary-background-color: hsl(0 0% 15%);
+  --tertiary-background-color: hsl(0 0% 20%);
+  --text-color: hsl(0 0% 90%);
+  --accent-color: #93c5fd;
+
+  color-scheme: dark;
+}
+
 html {
   scroll-behavior: smooth;
 }