frontend/Cargo.toml

@@ -16,7 +16,8 @@ serde = { workspace = true }
 wasm-bindgen-futures = "0.4.70"
 web-sys = { version = "0.3.95", features = [
   "Window","Document","Request","Response","Headers", "HtmlSelectElement", "RequestCredentials",
-  "SubmitEvent","InputEvent","HtmlInputElement","Event", "HtmlFormElement", "MouseEvent"
+  "SubmitEvent","InputEvent","HtmlInputElement","Event", "HtmlFormElement", "MouseEvent",
+  "Element", "MediaQueryList", "DomTokenList"
 ] }
 gloo-net = "0.7.0"
 gloo-storage = "0.4.0"

frontend/src/dark_mode.rs

@@ -0,0 +1,65 @@
+use gloo_storage::{LocalStorage, Storage};
+use web_sys::window;
+use yew::prelude::*;
+
+#[function_component(DarkModeToggle)]
+pub fn dark_mode_toggle() -> Html {
+    // 1. Initialize state from LocalStorage or system preference
+    let is_dark = use_state(|| {
+        LocalStorage::get::<bool>("dark-mode").unwrap_or_else(|_| {
+            // Fallback to system preference if not set
+            window()
+                .and_then(|w| w.match_media("(prefers-color-scheme: dark)").ok().flatten())
+                .map(|m| m.matches())
+                .unwrap_or(false)
+        })
+    });
+
+    // 2. Synchronize the class on the body when the state changes
+    {
+        let is_dark = is_dark.clone();
+        use_effect_with(is_dark, |is_dark| {
+            if let Some(win) = window() {
+                if let Some(doc) = win.document() {
+                    if let Some(body) = doc.body() {
+                        if **is_dark {
+                            let _ = body.class_list().add_1("theme-dark");
+                            let _ = body.class_list().remove_1("theme-light");
+                            let _ = LocalStorage::set("dark-mode", true);
+                        } else {
+                            let _ = body.class_list().add_1("theme-light");
+                            let _ = body.class_list().remove_1("theme-dark");
+                            let _ = LocalStorage::set("dark-mode", false);
+                        }
+                    }
+                }
+            }
+            || ()
+        });
+    }
+
+    // 3. Toggle action
+    let onclick = {
+        let is_dark = is_dark.clone();
+        Callback::from(move |_| {
+            is_dark.set(!*is_dark);
+        })
+    };
+
+    html! {
+        <button class="dark-mode-toggle" {onclick}>
+            if *is_dark {
+                // Sun Icon for switching to light mode
+                <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                    <circle cx="12" cy="12" r="4"/>
+                    <path d="M12 2v2M12 20v2M4.93 4.93l1.41 1.41M17.66 17.66l1.41 1.41M2 12h2M20 12h2M6.34 17.66l-1.41 1.41M19.07 4.93l-1.41 1.41"/>
+                </svg>
+            } else {
+                // Moon Icon for switching to dark mode
+                <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                    <path d="M12 3a6 6 0 0 0 9 9 9 9 0 1 1-9-9Z"/>
+                </svg>
+            }
+        </button>
+    }
+}

frontend/src/lib.rs

@@ -1,5 +1,6 @@
 mod auth;
 mod pages;
+mod dark_mode;
 use crate::auth::ProtectedRoute;
 use crate::pages::*;
 use gloo_net::http::Request;
@@ -271,6 +272,7 @@ fn switch(route: Route) -> Html {
 pub fn app() -> Html {
     html! {
         <BrowserRouter>
+            <dark_mode::DarkModeToggle />
             <Switch<Route> render={switch} />
         </BrowserRouter>
     }

frontend/src/styles/_variables.scss

@@ -1,15 +1,15 @@
 // Color Palette (Reference Style)
-$color-bg: #f0f2f5;
-$color-bg-dark: #121212;
-$color-container: #ffffff;
-$color-container-dark: #333333;
+$color-bg: var(--color-bg);
+$color-bg-dark: var(--color-bg-dark);
+$color-container: var(--color-container);
+$color-container-dark: var(--color-container-dark);
 $color-sidebar: #0f172a;
 $color-primary: #2b79c2;
 $color-primary-hover: #1d5fa0;
 $color-accent: #2b79c2;
 $color-muted: #6b7280;
-$color-text: #111827;
-$color-text-dark: #e2e2e2;
+$color-text: var(--color-text);
+$color-text-dark: var(--color-text-dark);
 
 // Status Colors
 $color-status-todo: #ffcccc;

frontend/src/styles/components/_dark_mode.scss

@@ -0,0 +1,75 @@
+:root {
+  --color-bg: #f0f2f5;
+  --color-bg-dark: #121212;
+  --color-container: #ffffff;
+  --color-container-dark: #333333;
+  --color-text: #111827;
+  --color-text-dark: #e2e2e2;
+}
+
+// Automatically respect standard media query if no override is set
+@media (prefers-color-scheme: dark) {
+  :root {
+    --color-bg: #121212;
+    --color-container: #333333;
+    --color-text: #e2e2e2;
+  }
+}
+
+// Force Light Mode overrides
+body.theme-light {
+  --color-bg: #f0f2f5;
+  --color-bg-dark: #f0f2f5;
+  --color-container: #ffffff;
+  --color-container-dark: #ffffff;
+  --color-text: #111827;
+  --color-text-dark: #111827;
+}
+
+// Force Dark Mode overrides
+body.theme-dark {
+  --color-bg: #121212;
+  --color-bg-dark: #121212;
+  --color-container: #333333;
+  --color-container-dark: #333333;
+  --color-text: #e2e2e2;
+  --color-text-dark: #e2e2e2;
+}
+
+// Fixed positioning ensures NO other component's layout is ever altered
+.dark-mode-toggle {
+  position: fixed;
+  top: 1rem;
+  right: 1rem;
+  z-index: 9999;
+  width: 55px;
+  height: 55px;
+  border-radius: 50%;
+  border: 1px solid rgba(128, 128, 128, 0.2);
+  background-color: var(--color-container);
+  color: var(--color-text);
+  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
+  cursor: pointer;
+  transition: all 0.2s ease-in-out;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: 0;
+
+  svg {
+    width: 36px;
+    height: 36px;
+    stroke: var(--color-text);
+    transition: stroke 0.2s ease-in-out;
+  }
+
+  &:hover {
+    transform: translateY(-1px);
+    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.15);
+    background-color: var(--color-bg);
+  }
+
+  &:active {
+    transform: translateY(0);
+  }
+}

frontend/src/styles/main.scss

@@ -10,6 +10,7 @@
 @use "components/diagnostics";
 @use "components/pages";
 @use "components/setup";
+@use "components/dark_mode";
 
 * {
   box-sizing: border-box;