diff --git a/apps/tauri/src-tauri/capabilities/default.json b/apps/tauri/src-tauri/capabilities/default.json
index b21cc4f..7ec93f1 100644
--- a/apps/tauri/src-tauri/capabilities/default.json
+++ b/apps/tauri/src-tauri/capabilities/default.json
@@ -10,6 +10,7 @@
     "core:window:allow-minimize",
     "core:window:allow-toggle-maximize",
     "core:window:allow-start-dragging",
-    "core:window:allow-is-maximized"
+    "core:window:allow-is-maximized",
+    "core:window:allow-set-decorations"
   ]
 }
diff --git a/apps/tauri/src/App.svelte b/apps/tauri/src/App.svelte
index cf89b8d..450bc1a 100644
--- a/apps/tauri/src/App.svelte
+++ b/apps/tauri/src/App.svelte
@@ -11,14 +11,18 @@
   onMount(() => {
     app.loadConfig();
   });
+
+  $effect(() => {
+    document.documentElement.classList.toggle("decorations-none", app.windowDecorations === "none");
+  });
 </script>
 
-<div class={app.isDark ? "dark" : ""} data-theme={app.currentTheme ?? ""}>
-  <div class="h-screen w-screen" class:p-2={isLinux && !app.systemDecorations}>
+<div class={app.isDark ? "dark" : ""} data-theme={app.currentTheme ?? ""} data-decorations={app.windowDecorations}>
+  <div class="h-screen w-screen" class:p-2={isLinux && app.windowDecorations === "custom"}>
     <div
       class="relative h-full w-full overflow-hidden bg-surface-light text-text-light dark:bg-surface-dark dark:text-text-dark"
-      class:rounded-xl={isLinux && !app.systemDecorations}
-      class:linux-window-border={isLinux && !app.systemDecorations}
+      class:rounded-xl={isLinux && app.windowDecorations === "custom"}
+      class:linux-window-border={isLinux && app.windowDecorations !== "system"}
       style="container-type: inline-size"
     >
       {#if app.error}
diff --git a/apps/tauri/src/app.css b/apps/tauri/src/app.css
index ad580fd..7da049f 100644
--- a/apps/tauri/src/app.css
+++ b/apps/tauri/src/app.css
@@ -248,6 +248,28 @@ body {
   border-color: rgba(0, 0, 0, 0.5);
 }
 
+/* ── Dropdown/kebab menu shadow ──────────────────────────────────── */
+
+.menu-shadow {
+  box-shadow: 0 4px 10px 0 rgba(0, 0, 0, 0.12);
+}
+.dark .menu-shadow {
+  box-shadow: 0 4px 10px 0 rgba(0, 0, 0, 0.3);
+}
+
+/* ── Borderless mode: square corners on all popups/overlays ─────── */
+
+.decorations-none .rounded-sm,
+.decorations-none .rounded,
+.decorations-none .rounded-md,
+.decorations-none .rounded-lg,
+.decorations-none .rounded-xl,
+.decorations-none .rounded-2xl,
+.decorations-none .rounded-3xl,
+.decorations-none .dropdown-menu button {
+  border-radius: 0 !important;
+}
+
 /* ── Accessibility: Reduced motion ───────────────────────────────── */
 
 @media (prefers-reduced-motion: reduce) {
diff --git a/apps/tauri/src/lib/components/TaskDetailView.svelte b/apps/tauri/src/lib/components/TaskDetailView.svelte
index 88a3498..f1fc699 100644
--- a/apps/tauri/src/lib/components/TaskDetailView.svelte
+++ b/apps/tauri/src/lib/components/TaskDetailView.svelte
@@ -160,7 +160,7 @@
       </svg>
     </button>
     {#if showMenu}
-      <div class="absolute right-0 top-full z-40 mt-1 min-w-[200px] rounded-lg border border-border-light bg-surface-light py-1 shadow-lg dark:border-border-dark dark:bg-surface-dark">
+      <div class="dropdown-menu absolute right-0 top-full z-40 mt-1 min-w-[200px] rounded-lg border border-border-light bg-surface-light py-1 menu-shadow dark:border-border-dark dark:bg-surface-dark">
         <button
           onclick={handleToggle}
           class="flex w-full items-center gap-2 px-3 py-2 text-left text-sm hover:bg-black/5 dark:hover:bg-white/10"
@@ -278,7 +278,7 @@
               </svg>
             </button>
             {#if showSubtaskMenu}
-              <div class="absolute right-0 top-full z-40 mt-1 min-w-[240px] rounded-lg border border-border-light bg-surface-light py-1 shadow-lg dark:border-border-dark dark:bg-surface-dark">
+              <div class="dropdown-menu absolute right-0 top-full z-40 mt-1 min-w-[240px] rounded-lg border border-border-light bg-surface-light py-1 menu-shadow dark:border-border-dark dark:bg-surface-dark">
                 <button
                   onclick={() => { showSubtaskMenu = false; confirmDeleteCompleted = true; }}
                   class="flex w-full items-center gap-2 px-3 py-2 text-left text-sm text-danger hover:bg-black/5 dark:hover:bg-white/10"
diff --git a/apps/tauri/src/lib/screens/SettingsScreen.svelte b/apps/tauri/src/lib/screens/SettingsScreen.svelte
index f038f8e..d63e617 100644
--- a/apps/tauri/src/lib/screens/SettingsScreen.svelte
+++ b/apps/tauri/src/lib/screens/SettingsScreen.svelte
@@ -136,7 +136,7 @@
       </svg>
     </button>
     {#if showKebab}
-      <div class="absolute right-0 top-full z-10 mt-1 w-40 rounded-xl border border-border-light bg-surface-light py-1 shadow-lg dark:border-border-dark dark:bg-surface-dark">
+      <div class="dropdown-menu absolute right-0 top-full z-10 mt-1 w-40 rounded-xl border border-border-light bg-surface-light py-1 menu-shadow dark:border-border-dark dark:bg-surface-dark">
         <button
           onclick={startRename}
           class="flex w-full items-center gap-2 px-4 py-2 text-sm hover:bg-black/5 dark:hover:bg-white/10"
@@ -271,18 +271,16 @@
   {#if isLinux}
     <!-- Window decorations (Linux only) -->
     <section class="mt-6">
-      <label class="flex cursor-pointer items-center justify-between gap-3">
-        <div>
-          <p class="text-sm font-medium">System window decorations</p>
-          <p class="text-xs opacity-50">Use the system title bar instead of the custom border</p>
-        </div>
-        <input
-          type="checkbox"
-          checked={app.systemDecorations}
-          onchange={(e) => app.setSystemDecorations((e.target as HTMLInputElement).checked)}
-          class="h-4 w-4 cursor-pointer accent-primary"
-        />
-      </label>
+      <label class="mb-1 block text-xs font-medium opacity-60">Window decorations</label>
+      <select
+        value={app.windowDecorations}
+        onchange={(e) => app.setWindowDecorations((e.target as HTMLSelectElement).value as "custom" | "none" | "system")}
+        class="w-full appearance-none rounded-lg border border-border-light bg-surface-light px-3 py-2 text-sm text-text-light outline-none focus:border-primary dark:border-border-dark dark:bg-surface-dark dark:text-text-dark"
+      >
+        <option value="custom">Custom border</option>
+        <option value="none">Borderless</option>
+        <option value="system">System title bar</option>
+      </select>
     </section>
   {/if}
 
diff --git a/apps/tauri/src/lib/screens/TasksScreen.svelte b/apps/tauri/src/lib/screens/TasksScreen.svelte
index b5457cb..0527799 100644
--- a/apps/tauri/src/lib/screens/TasksScreen.svelte
+++ b/apps/tauri/src/lib/screens/TasksScreen.svelte
@@ -290,7 +290,7 @@
         {#if showWorkspacePicker}
           <!-- svelte-ignore a11y_no_static_element_interactions -->
           <div
-            class="absolute left-0 top-full z-40 mt-1 w-full rounded-lg border border-border-light bg-surface-light py-1 shadow-lg dark:border-border-dark dark:bg-surface-dark"
+            class="dropdown-menu absolute left-0 top-full z-40 mt-1 w-full rounded-lg border border-border-light bg-surface-light py-1 menu-shadow dark:border-border-dark dark:bg-surface-dark"
           >
             {#each workspaceIds as wsId}
               {@const ws = app.config?.workspaces[wsId]}
@@ -500,7 +500,7 @@
                 </svg>
               </button>
               {#if showListMenu}
-                <div class="absolute right-0 top-full z-40 mt-1 min-w-[200px] rounded-lg border border-border-light bg-surface-light py-1 shadow-lg dark:border-border-dark dark:bg-surface-dark">
+                <div class="dropdown-menu absolute right-0 top-full z-40 mt-1 min-w-[200px] rounded-lg border border-border-light bg-surface-light py-1 menu-shadow dark:border-border-dark dark:bg-surface-dark">
                   <button
                     onclick={startRenameList}
                     class="flex w-full items-center gap-2 px-3 py-2 text-left text-sm hover:bg-black/5 dark:hover:bg-white/10"
diff --git a/apps/tauri/src/lib/stores/app.svelte.ts b/apps/tauri/src/lib/stores/app.svelte.ts
index 4f09d8e..22179dc 100644
--- a/apps/tauri/src/lib/stores/app.svelte.ts
+++ b/apps/tauri/src/lib/stores/app.svelte.ts
@@ -18,9 +18,12 @@ listen("fs-changed", () => {
 
 // ── Reactive state ───────────────────────────────────────────────────
 
-const LS_DECORATIONS_KEY = "systemDecorations";
-let systemDecorations = $state(localStorage.getItem(LS_DECORATIONS_KEY) === "true");
-if (systemDecorations) getCurrentWindow().setDecorations(true);
+const LS_DECORATIONS_KEY = "windowDecorations";
+let windowDecorations = $state<"custom" | "none" | "system">(
+  (localStorage.getItem(LS_DECORATIONS_KEY) as "custom" | "none" | "system") ?? "custom"
+);
+if (windowDecorations === "system") getCurrentWindow().setDecorations(true);
+if (windowDecorations === "none") document.documentElement.classList.add("decorations-none");
 
 let screen = $state<Screen>("setup");
 let config = $state<AppConfig | null>(null);
@@ -433,10 +436,11 @@ async function setSyncIntervalUnfocused(secs: number | null) {
   }
 }
 
-function setSystemDecorations(value: boolean) {
-  systemDecorations = value;
-  localStorage.setItem(LS_DECORATIONS_KEY, String(value));
-  getCurrentWindow().setDecorations(value);
+function setWindowDecorations(value: "custom" | "none" | "system") {
+  windowDecorations = value;
+  localStorage.setItem(LS_DECORATIONS_KEY, value);
+  getCurrentWindow().setDecorations(value === "system");
+  document.documentElement.classList.toggle("decorations-none", value === "none");
 }
 
 async function setTheme(theme: string | null) {
@@ -559,8 +563,8 @@ export const app = {
   get lastSyncResult() {
     return lastSyncResult;
   },
-  get systemDecorations() {
-    return systemDecorations;
+  get windowDecorations() {
+    return windowDecorations;
   },
   get error() {
     return error;
@@ -595,7 +599,7 @@ export const app = {
   stopAutoSync,
   setSyncInterval,
   setSyncIntervalUnfocused,
-  setSystemDecorations,
+  setWindowDecorations,
   setTheme,
   addWebdavWorkspace,
   forgetMissingWorkspace,