diff --git a/src/editor/AssetsDrawer.tsx b/src/editor/AssetsDrawer.tsx
index 5231439..1021799 100644
--- a/src/editor/AssetsDrawer.tsx
+++ b/src/editor/AssetsDrawer.tsx
@@ -48,10 +48,10 @@ export function AssetsDrawer({ onInsert, onClose, onUpload }: Props) {
   };
 
   return (
-    <aside className="assets-drawer" role="dialog" aria-label="Asset library">
-      <header className="assets-drawer__head">
-        <h2>Assets</h2>
-        <button type="button" className="assets-drawer__close" onClick={onClose} aria-label="Close">
+    <aside className="drawer assets-drawer" role="dialog" aria-label="Asset library">
+      <header className="drawer__header">
+        <h2 className="drawer__title">Assets</h2>
+        <button type="button" className="drawer__close" onClick={onClose} aria-label="Close">
           ×
         </button>
       </header>
diff --git a/src/editor/Editor.tsx b/src/editor/Editor.tsx
index da34de9..9c6f6f5 100644
--- a/src/editor/Editor.tsx
+++ b/src/editor/Editor.tsx
@@ -288,7 +288,10 @@ export function Editor({ deckId }: Props) {
             className={`editor__nav-link editor__nav-link--button ${
               assetsOpen ? 'editor__nav-link--active' : ''
             }`}
-            onClick={() => setAssetsOpen((v) => !v)}
+            onClick={() => {
+              setAssetsOpen((v) => !v);
+              setDrawerOpen(false);
+            }}
             aria-pressed={assetsOpen}
           >
             Assets
@@ -298,7 +301,10 @@ export function Editor({ deckId }: Props) {
             className={`editor__nav-link editor__nav-link--button ${
               drawerOpen ? 'editor__nav-link--active' : ''
             }`}
-            onClick={() => setDrawerOpen((v) => !v)}
+            onClick={() => {
+              setDrawerOpen((v) => !v);
+              setAssetsOpen(false);
+            }}
             aria-pressed={drawerOpen}
           >
             Design
diff --git a/src/editor/editor.css b/src/editor/editor.css
index a0f69b4..1d13135 100644
--- a/src/editor/editor.css
+++ b/src/editor/editor.css
@@ -1508,52 +1508,7 @@
   line-height: 1;
 }
 
-/* ─── Assets drawer ─────────────────────────────────────────────────────── */
-
-.assets-drawer {
-  position: absolute;
-  top: 0;
-  right: 0;
-  bottom: 0;
-  width: 360px;
-  background: var(--surface);
-  border-left: 1px solid var(--line);
-  display: flex;
-  flex-direction: column;
-  z-index: 30;
-  box-shadow: -16px 0 32px -16px rgba(0, 0, 0, 0.25);
-}
-
-.assets-drawer__head {
-  display: flex;
-  align-items: center;
-  justify-content: space-between;
-  padding: 16px 20px;
-  border-bottom: 1px solid var(--line);
-}
-
-.assets-drawer__head h2 {
-  margin: 0;
-  font-size: 14px;
-  font-weight: 600;
-  letter-spacing: 0.04em;
-  text-transform: uppercase;
-  color: var(--text);
-}
-
-.assets-drawer__close {
-  background: transparent;
-  border: none;
-  color: var(--text-muted);
-  font-size: 22px;
-  line-height: 1;
-  cursor: pointer;
-  padding: 4px 8px;
-}
-
-.assets-drawer__close:hover {
-  color: var(--text);
-}
+/* ─── Assets drawer (rides on top of the shared .drawer styles) ────── */
 
 .assets-drawer__upload {
   padding: 16px 20px;
diff --git a/src/ir/source-edit.ts b/src/ir/source-edit.ts
index 01713dd..65d6616 100644
--- a/src/ir/source-edit.ts
+++ b/src/ir/source-edit.ts
@@ -1,9 +1,12 @@
 import matter from 'gray-matter';
 
+const SLIDE_MARKER_RE = /^::slide(\{[^}]*\})?\s*$/;
+
 /**
- * Split the markdown source into slide sections without losing frontmatter.
- * Returns the frontmatter prefix plus an array of slide-section strings, each
- * including its leading `::slide` line if present.
+ * Split markdown into a frontmatter prefix and a list of marker-less slide
+ * chunks. The first slide implicitly has no `::slide` marker; subsequent
+ * slides start with one. We strip the marker from every chunk so reordering
+ * can shuffle slides freely; `joinSlides` re-emits markers between them.
  */
 function splitSourceIntoSlides(source: string): { prefix: string; slides: string[] } {
   const fm = matter(source);
@@ -11,30 +14,35 @@ function splitSourceIntoSlides(source: string): { prefix: string; slides: string
   const lines = body.split('\n');
   const sections: string[][] = [[]];
   for (const line of lines) {
-    if (/^::slide(\{[^}]*\})?\s*$/.test(line)) {
-      sections.push([line]);
+    if (SLIDE_MARKER_RE.test(line)) {
+      sections.push([]);
       continue;
     }
     sections[sections.length - 1].push(line);
   }
-  const slides = sections.map((chunk) => chunk.join('\n'));
-  // The first chunk may be empty if the very first line is ::slide; that is
-  // still a slide. Filter out an empty leading chunk only when there is no
-  // body content at all, otherwise preserve.
+  // If the body started with `::slide` (or only blank lines before one),
+  // the leading empty section is just whitespace — drop it so we don't
+  // turn it into a phantom slide.
+  if (sections.length > 1 && sections[0].every((l) => l.trim() === '')) {
+    sections.shift();
+  }
+  const slides = sections.map((chunk) => chunk.join('\n').trim());
   const fmPrefix = source.slice(0, source.length - body.length);
   return { prefix: fmPrefix, slides };
 }
 
 function joinSlides(prefix: string, slides: string[]): string {
-  // Reassemble with the original frontmatter prefix plus the slide chunks
-  // joined back with newlines. Each chunk that started with ::slide already
-  // carries that marker; the very first chunk does not, so we just join.
-  return prefix + slides.join('\n').replace(/\n+$/, '\n');
+  if (slides.length === 0) return prefix;
+  const body = slides.filter((s) => s.length > 0).join('\n\n::slide\n\n');
+  let out = prefix;
+  if (out.length > 0 && !out.endsWith('\n')) out += '\n';
+  if (out.length > 0) out += '\n';
+  return out + body + '\n';
 }
 
 /**
- * Move slide at `from` index so it appears at `to` index. Pure: same input,
- * same output. Returns the new source string. Out-of-range indices are no-ops.
+ * Move slide at `from` to position `to`. Out-of-range indices and `from === to`
+ * are no-ops. Pure: same input, same output.
  */
 export function reorderSlide(source: string, from: number, to: number): string {
   if (from === to) return source;
diff --git a/tests/ir/source-edit.test.ts b/tests/ir/source-edit.test.ts
index fcead35..da2083f 100644
--- a/tests/ir/source-edit.test.ts
+++ b/tests/ir/source-edit.test.ts
@@ -48,4 +48,24 @@ title: Demo
     const next = reorderSlide(sample, 0, 2);
     expect(next).toMatch(/^---\ntitle: Demo\n---/);
   });
+
+  it('preserves slide count after a reorder (no merge, no phantom slide)', () => {
+    const moves: [number, number][] = [
+      [0, 2],
+      [2, 0],
+      [1, 0],
+      [0, 1],
+    ];
+    for (const [from, to] of moves) {
+      const next = reorderSlide(sample, from, to);
+      expect(countSlides(next)).toBe(3);
+    }
+  });
+
+  it('handles a body that starts with ::slide marker without phantom slide', () => {
+    const src = '::slide\n\n# A\n\n::slide\n\n# B\n';
+    expect(countSlides(src)).toBe(2);
+    const next = reorderSlide(src, 0, 1);
+    expect(countSlides(next)).toBe(2);
+  });
 });