diff --git a/frontend/src/lib/components/IconButton.svelte b/frontend/src/lib/components/IconButton.svelte
index 6826f05..08a1852 100644
--- a/frontend/src/lib/components/IconButton.svelte
+++ b/frontend/src/lib/components/IconButton.svelte
@@ -2,23 +2,36 @@
     import type { Snippet } from 'svelte';
     import type { HTMLButtonAttributes } from 'svelte/elements';
 
-    // Shared square icon button — extracted from five near-identical
-    // `.icon-btn` copies (collections, manga edit, upload, the chapter-pages
-    // editor) so the size, hover, and variant treatment live in one place.
-    // Callers pass the lucide icon as the child and any button attributes
-    // (onclick, disabled, aria-label, title, data-testid) straight through.
+    // Shared square icon button — extracted from the near-identical
+    // `.icon-btn` copies across the app so the size, hover, and variant
+    // treatment live in one place. Callers pass the lucide icon as the child
+    // and any button attributes (onclick, disabled, aria-label, title,
+    // data-testid) straight through. `size`/`radius` cover the two larger
+    // header/search buttons without forcing the 32px default everywhere.
     type Variant = 'plain' | 'primary' | 'danger';
 
     let {
         variant = 'plain',
+        size = 32,
+        radius = 'sm',
         children,
         ...rest
-    }: { variant?: Variant; children: Snippet } & HTMLButtonAttributes = $props();
+    }: {
+        variant?: Variant;
+        size?: number;
+        radius?: 'sm' | 'md';
+        children: Snippet;
+    } & HTMLButtonAttributes = $props();
 </script>
 
 <!-- `type="button"` precedes the spread so a caller can still override it
      (e.g. a submit button) while the default never submits a form. -->
-<button type="button" class="icon-btn {variant}" {...rest}>
+<button
+    type="button"
+    class="icon-btn {variant} radius-{radius}"
+    style:--ib-size="{size}px"
+    {...rest}
+>
     {@render children()}
 </button>
 
@@ -27,16 +40,23 @@
         display: inline-flex;
         align-items: center;
         justify-content: center;
-        width: 32px;
-        height: 32px;
+        width: var(--ib-size, 32px);
+        height: var(--ib-size, 32px);
         padding: 0;
         background: transparent;
         color: var(--text-muted);
         border: 1px solid transparent;
-        border-radius: var(--radius-sm);
         cursor: pointer;
     }
 
+    .radius-sm {
+        border-radius: var(--radius-sm);
+    }
+
+    .radius-md {
+        border-radius: var(--radius-md);
+    }
+
     .icon-btn:hover:not(:disabled) {
         background: var(--surface-elevated);
         color: var(--text);
diff --git a/frontend/src/lib/components/IconButton.svelte.test.ts b/frontend/src/lib/components/IconButton.svelte.test.ts
index 0be4512..46e1769 100644
--- a/frontend/src/lib/components/IconButton.svelte.test.ts
+++ b/frontend/src/lib/components/IconButton.svelte.test.ts
@@ -37,6 +37,23 @@ describe('IconButton', () => {
         expect(c2.querySelector('button.icon-btn.danger')).toBeTruthy();
     });
 
+    it('defaults to a 32px square with the small radius', () => {
+        const { container } = render(IconButton, { props: { children: icon } });
+        const btn = container.querySelector('button.icon-btn') as HTMLButtonElement;
+        expect(btn.classList.contains('radius-sm')).toBe(true);
+        expect(btn.style.getPropertyValue('--ib-size')).toBe('32px');
+    });
+
+    it('honours an explicit size and radius (the larger header/search buttons)', () => {
+        const { container } = render(IconButton, {
+            props: { size: 36, radius: 'md', children: icon }
+        });
+        const btn = container.querySelector('button.icon-btn') as HTMLButtonElement;
+        expect(btn.style.getPropertyValue('--ib-size')).toBe('36px');
+        expect(btn.classList.contains('radius-md')).toBe(true);
+        expect(btn.classList.contains('radius-sm')).toBe(false);
+    });
+
     it('forwards onclick', async () => {
         const onclick = vi.fn();
         render(IconButton, { props: { onclick, children: icon } });
diff --git a/frontend/src/routes/+layout.svelte b/frontend/src/routes/+layout.svelte
index c8d4095..c621b41 100644
--- a/frontend/src/routes/+layout.svelte
+++ b/frontend/src/routes/+layout.svelte
@@ -9,6 +9,7 @@
     import { theme } from '$lib/theme.svelte';
     import AppBar from '$lib/components/AppBar.svelte';
     import BottomNav, { type BottomNavTab } from '$lib/components/BottomNav.svelte';
+    import IconButton from '$lib/components/IconButton.svelte';
     import Upload from '@lucide/svelte/icons/upload';
     import UserCircle from '@lucide/svelte/icons/user-circle';
     import Bookmark from '@lucide/svelte/icons/bookmark';
@@ -232,9 +233,9 @@
             <span data-testid="session-loading" aria-busy="true">…</span>
         {:else if session.user}
             <span class="username" data-testid="session-user">{session.user.username}</span>
-            <button
-                class="icon-btn"
-                type="button"
+            <IconButton
+                size={36}
+                radius="md"
                 onclick={handleLogout}
                 disabled={loggingOut}
                 aria-label="Logout"
@@ -245,7 +246,7 @@
                 {:else}
                     <LogOut size={18} aria-hidden="true" />
                 {/if}
-            </button>
+            </IconButton>
         {:else}
             <a class="text-link" href="/login" data-testid="nav-login">Login</a>
             {#if authConfig.self_register_enabled}
@@ -348,24 +349,6 @@
         padding: 0 var(--space-2);
     }
 
-    .icon-btn {
-        display: inline-flex;
-        align-items: center;
-        justify-content: center;
-        width: 36px;
-        height: 36px;
-        padding: 0;
-        background: transparent;
-        color: var(--text-muted);
-        border: 1px solid transparent;
-        border-radius: var(--radius-md);
-    }
-
-    .icon-btn:hover:not(:disabled) {
-        background: var(--surface-elevated);
-        color: var(--text);
-    }
-
     .logging-out {
         font-size: var(--font-base);
         line-height: 1;
diff --git a/frontend/src/routes/+page.svelte b/frontend/src/routes/+page.svelte
index 683dea9..b6b8209 100644
--- a/frontend/src/routes/+page.svelte
+++ b/frontend/src/routes/+page.svelte
@@ -27,6 +27,7 @@
     import Pager from '$lib/components/Pager.svelte';
     import SegmentedControl from '$lib/components/SegmentedControl.svelte';
     import Sheet from '$lib/components/Sheet.svelte';
+    import IconButton from '$lib/components/IconButton.svelte';
     import Search from '@lucide/svelte/icons/search';
     import SlidersHorizontal from '@lucide/svelte/icons/sliders-horizontal';
     import ArrowUpDown from '@lucide/svelte/icons/arrow-up-down';
@@ -467,9 +468,16 @@
             placeholder="Search by title or author"
             data-testid="search-input"
         />
-        <button class="icon-btn primary" type="submit" aria-label="Search" title="Search">
+        <IconButton
+            variant="primary"
+            size={36}
+            radius="md"
+            type="submit"
+            aria-label="Search"
+            title="Search"
+        >
             <Search size={18} aria-hidden="true" />
-        </button>
+        </IconButton>
         <button
             type="button"
             class="filters-toggle"
@@ -923,26 +931,6 @@
         border-color: var(--primary-hover);
     }
 
-    .icon-btn {
-        display: inline-flex;
-        align-items: center;
-        justify-content: center;
-        width: 36px;
-        height: 36px;
-        padding: 0;
-    }
-
-    .icon-btn.primary {
-        background: var(--primary);
-        color: var(--primary-contrast);
-        border: 1px solid var(--primary);
-    }
-
-    .icon-btn.primary:hover:not(:disabled) {
-        background: var(--primary-hover);
-        border-color: var(--primary-hover);
-    }
-
     .status {
         color: var(--text-muted);
     }