diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2acfc81..cc113d9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,7 +7,22 @@ this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
-Nothing yet.
+### Fixed
+- The security note in the ID generator rendered as overlapping fragments. It
+  was a paragraph with `display: flex`, which makes every inline child — both
+  text runs and the inline `<code>` — a separate flex item laid out in a row.
+- Dropdowns had cramped padding and the native arrow overlapped the border at
+  our control height. The native arrow is now suppressed and replaced with a
+  chevron drawn inside the padding box, with room reserved for it.
+- The preset dropdown always displayed "Preset…" regardless of the settings in
+  use. It now shows whichever preset the current options match, derived from
+  those options rather than stored, so it survives a reload and falls back to
+  "Custom" as soon as any field changes.
+
+### Changed
+- The sidebar collapse control moved from the bottom of the tool list to the
+  top, where it is visible without scrolling, and the collapse now animates.
+  Both respect `prefers-reduced-motion`.
 
 ## [0.2.2] — 2026-09-24
 
diff --git a/src/components/layout/Sidebar.tsx b/src/components/layout/Sidebar.tsx
index ff2cdce..64d9c3d 100644
--- a/src/components/layout/Sidebar.tsx
+++ b/src/components/layout/Sidebar.tsx
@@ -54,7 +54,11 @@ function ToolLinks({
                 }
               >
                 <tool.icon size={15} aria-hidden className="shrink-0" />
-                {!collapsed && <span className="truncate">{tool.title}</span>}
+                {!collapsed && (
+                  <span className="truncate opacity-0 animate-[fadeIn_150ms_ease-out_forwards]">
+                    {tool.title}
+                  </span>
+                )}
               </NavLink>
             ))}
           </div>
@@ -70,35 +74,40 @@ export function Sidebar() {
   return (
     <aside
       className={cn(
-        'hidden shrink-0 flex-col border-r border-border bg-surface md:flex',
+        'hidden shrink-0 flex-col overflow-hidden border-r border-border bg-surface md:flex',
+        // Animating width needs overflow-hidden above, or the labels spill
+        // across the main pane mid-transition. Respects reduced-motion.
+        'transition-[width] duration-200 ease-out motion-reduce:transition-none',
         sidebarCollapsed ? 'w-[52px]' : 'w-[220px]',
       )}
     >
-      <div className="min-h-0 flex-1 overflow-y-auto scroll-thin">
-        <ToolLinks collapsed={sidebarCollapsed} />
-      </div>
-
-      <button
-        type="button"
-        onClick={toggleSidebar}
-        title={sidebarCollapsed ? 'Expand sidebar' : 'Collapse sidebar'}
-        aria-label={sidebarCollapsed ? 'Expand sidebar' : 'Collapse sidebar'}
-        aria-expanded={!sidebarCollapsed}
+      {/* At the top, where it is actually visible, and aligned with the header
+          row rather than buried under the tool list. */}
+      <div
         className={cn(
-          'flex min-h-9 shrink-0 items-center gap-2 border-t border-border px-3 text-[12px]',
-          'text-faint hover:bg-surface-2 hover:text-fg',
-          sidebarCollapsed && 'justify-center px-0',
+          'flex h-9 shrink-0 items-center border-b border-border',
+          sidebarCollapsed ? 'justify-center px-0' : 'justify-end px-2',
         )}
       >
-        {sidebarCollapsed ? (
-          <PanelLeftOpen size={15} aria-hidden />
-        ) : (
-          <>
+        <button
+          type="button"
+          onClick={toggleSidebar}
+          title={sidebarCollapsed ? 'Expand sidebar' : 'Collapse sidebar'}
+          aria-label={sidebarCollapsed ? 'Expand sidebar' : 'Collapse sidebar'}
+          aria-expanded={!sidebarCollapsed}
+          className="flex size-7 items-center justify-center rounded-[4px] text-faint hover:bg-surface-2 hover:text-fg"
+        >
+          {sidebarCollapsed ? (
+            <PanelLeftOpen size={15} aria-hidden />
+          ) : (
             <PanelLeftClose size={15} aria-hidden />
-            <span>Collapse</span>
-          </>
-        )}
-      </button>
+          )}
+        </button>
+      </div>
+
+      <div className="min-h-0 flex-1 overflow-y-auto scroll-thin">
+        <ToolLinks collapsed={sidebarCollapsed} />
+      </div>
     </aside>
   )
 }
diff --git a/src/components/ui/Select.tsx b/src/components/ui/Select.tsx
index c8aabc2..35ae8d3 100644
--- a/src/components/ui/Select.tsx
+++ b/src/components/ui/Select.tsx
@@ -1,12 +1,25 @@
 import type { ReactNode, SelectHTMLAttributes } from 'react'
 import { cn } from '@/lib/util/cn'
 
-export function Select({ className, ...rest }: SelectHTMLAttributes<HTMLSelectElement>) {
+/**
+ * The native arrow sits outside the padding box and cannot be styled, so it
+ * collides with the border at our control height. We suppress it with
+ * appearance-none and draw our own chevron as a background image, leaving
+ * explicit room for it on the right.
+ */
+const CHEVRON =
+  "url(\"data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='%238b8d98' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m4 6 4 4 4-4'/%3E%3C/svg%3E\")"
+
+export function Select({ className, style, ...rest }: SelectHTMLAttributes<HTMLSelectElement>) {
   return (
     <select
+      style={{ backgroundImage: CHEVRON, ...style }}
       className={cn(
-        'min-h-11 shrink-0 rounded-[4px] border border-border bg-bg px-1.5 text-fg',
-        'hover:border-border-strong md:min-h-7',
+        'min-h-11 shrink-0 appearance-none rounded-[4px] border border-border bg-bg',
+        // Room for the chevron on the right, comfortable text inset on the left.
+        'py-1 pl-2.5 pr-8 text-fg',
+        'bg-[length:14px_14px] bg-[right_8px_center] bg-no-repeat',
+        'hover:border-border-strong md:min-h-7 md:py-0',
         className,
       )}
       {...rest}
@@ -29,7 +42,6 @@ export function Toggle({
         type="checkbox"
         checked={checked}
         onChange={(e) => onChange(e.target.checked)}
-        // 14px box, inverse fill when checked, per the design's checkbox spec.
         className="size-3.5 appearance-none rounded-[3px] border border-border bg-bg
                    checked:border-fg checked:bg-fg
                    checked:bg-[url('data:image/svg+xml;utf8,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 16 16%22><path d=%22M3.5 8.5l3 3 6-6%22 fill=%22none%22 stroke=%22%23121316%22 stroke-width=%222.5%22 stroke-linecap=%22round%22 stroke-linejoin=%22round%22/></svg>')]
diff --git a/src/styles/global.css b/src/styles/global.css
index 7f4da3e..809f740 100644
--- a/src/styles/global.css
+++ b/src/styles/global.css
@@ -191,3 +191,21 @@ textarea:focus-visible,
 .cm-mergeView .cm-editor {
   height: 100%;
 }
+
+/* Labels fade in as the sidebar expands, so they do not appear fully formed
+   before the width animation has finished. */
+@keyframes fadeIn {
+  from {
+    opacity: 0;
+  }
+  to {
+    opacity: 1;
+  }
+}
+
+@media (prefers-reduced-motion: reduce) {
+  [class*='animate-'] {
+    animation: none !important;
+    opacity: 1 !important;
+  }
+}
diff --git a/src/tools/id-gen/IdGenTool.tsx b/src/tools/id-gen/IdGenTool.tsx
index efee17d..4774aba 100644
--- a/src/tools/id-gen/IdGenTool.tsx
+++ b/src/tools/id-gen/IdGenTool.tsx
@@ -13,6 +13,7 @@ import { copyText } from '@/lib/util/clipboard'
 import { formatCount } from '@/lib/util/bytes'
 import {
   DEFAULT_OPTIONS,
+  matchingPreset,
   MAX_COUNT,
   MAX_LENGTH,
   PRESETS,
@@ -99,14 +100,14 @@ export default function IdGenTool() {
       actions={
         <>
           <Select
-            value=""
+            value={matchingPreset(state) ?? ''}
             onChange={(e) => {
               const preset = PRESETS.find((p) => p.name === e.target.value)
               if (preset) applyOptions((p) => ({ ...p, ...preset.options }))
             }}
             title="Load a preset"
           >
-            <option value="">Preset…</option>
+            <option value="">Custom</option>
             {PRESETS.map((p) => (
               <option key={p.name} value={p.name} title={p.description}>
                 {p.name}
@@ -249,10 +250,20 @@ export default function IdGenTool() {
             </p>
           </div>
 
-          <p className="mt-3 flex items-start gap-1.5 text-[11px] leading-snug text-faint">
-            <ShieldCheck size={13} className="mt-px shrink-0 text-add" aria-hidden />
-            Generated with <code className="font-mono">crypto.getRandomValues</code> and unbiased
-            sampling. Your settings are saved; the generated values never are.
+          {/* Deliberately not a flex container: flex would make each inline
+              child -- both text runs and the <code> -- a separate flex item,
+              which is what made this overlap. The icon is inline instead. */}
+          <p className="mt-3 text-[11px] leading-[1.6] text-faint">
+            <ShieldCheck
+              size={12}
+              className="mr-1 inline-block shrink-0 align-[-1px] text-add"
+              aria-hidden
+            />
+            Generated with{' '}
+            <code className="rounded-[3px] bg-surface-2 px-1 py-px font-mono text-[10px] text-muted">
+              crypto.getRandomValues
+            </code>{' '}
+            and unbiased sampling. Your settings are saved; the generated values never are.
           </p>
         </div>
 
diff --git a/src/tools/id-gen/core/generate.test.ts b/src/tools/id-gen/core/generate.test.ts
index ed92fa4..bc0515c 100644
--- a/src/tools/id-gen/core/generate.test.ts
+++ b/src/tools/id-gen/core/generate.test.ts
@@ -9,6 +9,7 @@ import {
   PRESETS,
   entropyBits,
   generateIds,
+  matchingPreset,
   resolveAlphabet,
   strength,
   type IdOptions,
@@ -232,3 +233,27 @@ describe('properties', () => {
     expect(counts.size).toBe(16)
   })
 })
+
+describe('matchingPreset', () => {
+  it('names the preset whose settings the options match', () => {
+    const stripe = PRESETS.find((p) => p.name === 'Stripe secret key')!
+    expect(matchingPreset(opts(stripe.options))).toBe('Stripe secret key')
+  })
+
+  it('returns null once any field is changed', () => {
+    const stripe = PRESETS.find((p) => p.name === 'Stripe secret key')!
+    expect(matchingPreset(opts({ ...stripe.options, length: 25 }))).toBeNull()
+  })
+
+  it('identifies every preset from its own options', () => {
+    for (const preset of PRESETS) {
+      expect(matchingPreset(opts(preset.options)), preset.name).toBe(preset.name)
+    }
+  })
+
+  it('ignores fields the preset does not specify', () => {
+    const stripe = PRESETS.find((p) => p.name === 'Stripe secret key')!
+    // count is not part of that preset, so changing it must not unmatch.
+    expect(matchingPreset(opts({ ...stripe.options, count: 99 }))).toBe('Stripe secret key')
+  })
+})
diff --git a/src/tools/id-gen/core/generate.ts b/src/tools/id-gen/core/generate.ts
index cb63ae4..5549522 100644
--- a/src/tools/id-gen/core/generate.ts
+++ b/src/tools/id-gen/core/generate.ts
@@ -217,3 +217,18 @@ export const PRESETS: readonly Preset[] = [
     options: { prefix: '', separator: '', length: 10, alphabet: 'base58', excludeAmbiguous: true },
   },
 ]
+
+/**
+ * Name the preset whose settings the current options match, if any.
+ *
+ * Derived rather than stored: the dropdown then shows the right thing after a
+ * reload, and falls back to "Custom" the moment any field is changed, with no
+ * state to keep in sync.
+ */
+export function matchingPreset(options: IdOptions): string | null {
+  for (const preset of PRESETS) {
+    const keys = Object.keys(preset.options) as (keyof IdOptions)[]
+    if (keys.every((k) => options[k] === preset.options[k])) return preset.name
+  }
+  return null
+}