diff --git a/src/components/MarkdownEditor.tsx b/src/components/MarkdownEditor.tsx
new file mode 100644
index 0000000..3d7c77c
--- /dev/null
+++ b/src/components/MarkdownEditor.tsx
@@ -0,0 +1,216 @@
+import { useRef, useState, type KeyboardEvent } from 'react';
+import {
+  BoldIcon,
+  CodeIcon,
+  EyeIcon,
+  HeadingIcon,
+  ItalicIcon,
+  LinkIcon,
+  ListIcon,
+  ListOrderedIcon,
+  PencilIcon,
+  QuoteIcon,
+  StrikethroughIcon,
+} from 'lucide-react';
+import MarkdownContent from './MarkdownContent';
+
+interface MarkdownEditorProps {
+  readonly value: string;
+  readonly onChange: (value: string) => void;
+  readonly placeholder?: string;
+  readonly rows?: number;
+  readonly disabled?: boolean;
+}
+
+type WrapAction = 'bold' | 'italic' | 'strike' | 'code' | 'link';
+type LineAction = 'h1' | 'h2' | 'h3' | 'ul' | 'ol' | 'quote';
+
+const WRAP_SYNTAX: Record<WrapAction, { prefix: string; suffix: string; placeholder: string }> = {
+  bold: { prefix: '**', suffix: '**', placeholder: 'bold text' },
+  italic: { prefix: '*', suffix: '*', placeholder: 'italic text' },
+  strike: { prefix: '~~', suffix: '~~', placeholder: 'strikethrough' },
+  code: { prefix: '`', suffix: '`', placeholder: 'code' },
+  link: { prefix: '[', suffix: '](https://)', placeholder: 'link text' },
+};
+
+const LINE_PREFIX: Record<LineAction, string> = {
+  h1: '# ',
+  h2: '## ',
+  h3: '### ',
+  ul: '- ',
+  ol: '1. ',
+  quote: '> ',
+};
+
+export default function MarkdownEditor({
+  value,
+  onChange,
+  placeholder = '# Hello world',
+  rows = 12,
+  disabled = false,
+}: MarkdownEditorProps) {
+  const textareaRef = useRef<HTMLTextAreaElement | null>(null);
+  const [mode, setMode] = useState<'write' | 'preview'>('write');
+
+  function applyWrap(action: WrapAction) {
+    const textarea = textareaRef.current;
+    if (!textarea || disabled) return;
+
+    const { prefix, suffix, placeholder: ph } = WRAP_SYNTAX[action];
+    const start = textarea.selectionStart;
+    const end = textarea.selectionEnd;
+    const selected = value.slice(start, end);
+    const inner = selected || ph;
+    const next = value.slice(0, start) + prefix + inner + suffix + value.slice(end);
+
+    onChange(next);
+    requestAnimationFrame(() => {
+      textarea.focus();
+      const selStart = start + prefix.length;
+      const selEnd = selStart + inner.length;
+      textarea.setSelectionRange(selStart, selEnd);
+    });
+  }
+
+  function applyLine(action: LineAction) {
+    const textarea = textareaRef.current;
+    if (!textarea || disabled) return;
+
+    const prefix = LINE_PREFIX[action];
+    const start = textarea.selectionStart;
+    const end = textarea.selectionEnd;
+    const lineStart = value.lastIndexOf('\n', start - 1) + 1;
+    const lineEnd = value.indexOf('\n', end);
+    const actualLineEnd = lineEnd === -1 ? value.length : lineEnd;
+    const lineBlock = value.slice(lineStart, actualLineEnd);
+
+    const lines = lineBlock.split('\n');
+    const isFirst = (i: number) => action === 'ol' && i > 0;
+    const transformed = lines
+      .map((line, i) => (isFirst(i) ? `${i + 1}. ` : prefix) + line)
+      .join('\n');
+
+    const next = value.slice(0, lineStart) + transformed + value.slice(actualLineEnd);
+    onChange(next);
+    requestAnimationFrame(() => {
+      textarea.focus();
+      textarea.setSelectionRange(lineStart, lineStart + transformed.length);
+    });
+  }
+
+  function handleKeyDown(event: KeyboardEvent<HTMLTextAreaElement>) {
+    if (disabled) return;
+    const mod = event.metaKey || event.ctrlKey;
+    if (!mod) return;
+
+    const key = event.key.toLowerCase();
+    const map: Record<string, () => void> = {
+      b: () => applyWrap('bold'),
+      i: () => applyWrap('italic'),
+      k: () => applyWrap('code'),
+    };
+    if (map[key]) {
+      event.preventDefault();
+      map[key]();
+    }
+  }
+
+  return (
+    <div className="md-editor">
+      <div className="md-editor__toolbar" role="toolbar" aria-label="Markdown formatting">
+        <div className="md-editor__group">
+          <ToolbarButton title="Heading 1 (Ctrl/Cmd+Alt+1)" disabled={disabled} onClick={() => applyLine('h1')}>
+            <HeadingIcon aria-hidden="true" size={15} />
+          </ToolbarButton>
+          <ToolbarButton title="Bold (Ctrl/Cmd+B)" disabled={disabled} onClick={() => applyWrap('bold')}>
+            <BoldIcon aria-hidden="true" size={15} />
+          </ToolbarButton>
+          <ToolbarButton title="Italic (Ctrl/Cmd+I)" disabled={disabled} onClick={() => applyWrap('italic')}>
+            <ItalicIcon aria-hidden="true" size={15} />
+          </ToolbarButton>
+          <ToolbarButton title="Strikethrough" disabled={disabled} onClick={() => applyWrap('strike')}>
+            <StrikethroughIcon aria-hidden="true" size={15} />
+          </ToolbarButton>
+        </div>
+        <div className="md-editor__divider" />
+        <div className="md-editor__group">
+          <ToolbarButton title="Link" disabled={disabled} onClick={() => applyWrap('link')}>
+            <LinkIcon aria-hidden="true" size={15} />
+          </ToolbarButton>
+          <ToolbarButton title="Inline code (Ctrl/Cmd+K)" disabled={disabled} onClick={() => applyWrap('code')}>
+            <CodeIcon aria-hidden="true" size={15} />
+          </ToolbarButton>
+          <ToolbarButton title="Bulleted list" disabled={disabled} onClick={() => applyLine('ul')}>
+            <ListIcon aria-hidden="true" size={15} />
+          </ToolbarButton>
+          <ToolbarButton title="Numbered list" disabled={disabled} onClick={() => applyLine('ol')}>
+            <ListOrderedIcon aria-hidden="true" size={15} />
+          </ToolbarButton>
+          <ToolbarButton title="Quote" disabled={disabled} onClick={() => applyLine('quote')}>
+            <QuoteIcon aria-hidden="true" size={15} />
+          </ToolbarButton>
+        </div>
+        <div className="md-editor__spacer" />
+        <div className="md-editor__mode-toggle">
+          <ToolbarButton title="Write" disabled={disabled} active={mode === 'write'} onClick={() => setMode('write')}>
+            <PencilIcon aria-hidden="true" size={14} />
+            <span>Write</span>
+          </ToolbarButton>
+          <ToolbarButton title="Preview" disabled={disabled} active={mode === 'preview'} onClick={() => setMode('preview')}>
+            <EyeIcon aria-hidden="true" size={14} />
+            <span>Preview</span>
+          </ToolbarButton>
+        </div>
+      </div>
+
+      {mode === 'write' ? (
+        <textarea
+          ref={textareaRef}
+          className="md-editor__textarea"
+          value={value}
+          onChange={(e) => onChange(e.target.value)}
+          onKeyDown={handleKeyDown}
+          placeholder={placeholder}
+          rows={rows}
+          disabled={disabled}
+          spellCheck
+        />
+      ) : (
+        <div className="md-editor__preview">
+          {value.trim() ? (
+            <MarkdownContent markdown={value} />
+          ) : (
+            <p className="muted">Nothing to preview yet.</p>
+          )}
+        </div>
+      )}
+    </div>
+  );
+}
+
+function ToolbarButton({
+  title,
+  onClick,
+  disabled,
+  active,
+  children,
+}: {
+  title: string;
+  onClick: () => void;
+  disabled?: boolean;
+  active?: boolean;
+  children: React.ReactNode;
+}) {
+  return (
+    <button
+      type="button"
+      className={`md-editor__btn${active ? ' is-active' : ''}`}
+      title={title}
+      aria-label={title}
+      onClick={onClick}
+      disabled={disabled}
+    >
+      {children}
+    </button>
+  );
+}
diff --git a/src/routes/LinkDetailPage.tsx b/src/routes/LinkDetailPage.tsx
index e547712..f7dc947 100644
--- a/src/routes/LinkDetailPage.tsx
+++ b/src/routes/LinkDetailPage.tsx
@@ -4,6 +4,7 @@ import { Chart, registerables } from 'chart.js';
 import { CheckIcon, CopyIcon, ExternalLinkIcon, GlobeIcon, LockIcon, MegaphoneIcon, PencilIcon, Trash2Icon } from 'lucide-react';
 import CopyPublicLinkDialog from '../components/CopyPublicLinkDialog';
 import MarkdownContent from '../components/MarkdownContent';
+import MarkdownEditor from '../components/MarkdownEditor';
 import PromotionDialog from '../components/PromotionDialog';
 import {
   ApiClientError,
@@ -529,7 +530,7 @@ export default function LinkDetailPage({ linkId, linkScope, currentUser, linkBas
           {copyError ? <p className="form-error" role="alert" style={{ marginTop: 0 }}>{copyError}</p> : null}
           {editError ? <p className="form-error" role="alert" style={{ marginTop: 0 }}>{editError}</p> : null}
           {editing && editInput ? (
-            <div className="form-card detail-edit-form">
+            <div className="form-card detail-edit-form link-form">
               <h2 style={{ fontSize: '1rem', fontWeight: 600, margin: '0 0 1rem' }}>Edit link</h2>
               <div className="field">
                 <label>Alias</label>
@@ -564,12 +565,9 @@ export default function LinkDetailPage({ linkId, linkScope, currentUser, linkBas
               ) : (
                 <div className="field">
                   <label htmlFor="edit-content">Markdown content</label>
-                  <textarea
-                    id="edit-content"
+                  <MarkdownEditor
                     value={editInput.contentMarkdown ?? ''}
-                    onChange={(e) => updateEdit('contentMarkdown', e.target.value)}
-                    required
-                    rows={10}
+                    onChange={(v) => updateEdit('contentMarkdown', v)}
                     placeholder="# Hello world"
                     disabled={saving}
                   />
diff --git a/src/styles.css b/src/styles.css
index f68e248..de03728 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -1667,6 +1667,84 @@ button.link-action--confirm:hover { background: var(--accent-soft); }
   background: var(--background); color: var(--muted); cursor: not-allowed;
 }
 
+/* Markdown editor */
+.md-editor {
+  border: 1px solid var(--border-strong);
+  border-radius: var(--radius-sm);
+  overflow: hidden;
+  transition: border-color 0.15s, box-shadow 0.15s;
+}
+.md-editor:focus-within {
+  border-color: var(--accent);
+  box-shadow: 0 0 0 3px var(--accent-soft);
+}
+.md-editor__toolbar {
+  align-items: center;
+  background: var(--background);
+  border-bottom: 1px solid var(--border);
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.15rem;
+  padding: 0.35rem 0.5rem;
+}
+.md-editor__group { display: flex; gap: 0.1rem; }
+.md-editor__divider {
+  width: 1px;
+  height: 1.1rem;
+  background: var(--border-strong);
+  margin: 0 0.3rem;
+}
+.md-editor__spacer { flex: 1; }
+.md-editor__mode-toggle { display: flex; gap: 0.1rem; }
+.md-editor__btn {
+  align-items: center;
+  background: transparent;
+  border: 1px solid transparent;
+  border-radius: 5px;
+  color: var(--muted);
+  cursor: pointer;
+  display: inline-flex;
+  font: inherit;
+  font-size: 0.75rem;
+  font-weight: 500;
+  gap: 0.3rem;
+  padding: 0.3rem 0.45rem;
+  transition: background 0.1s, color 0.1s, border-color 0.1s;
+}
+.md-editor__btn:hover {
+  background: var(--surface);
+  border-color: var(--border);
+  color: var(--text);
+}
+.md-editor__btn.is-active {
+  background: var(--accent-soft);
+  border-color: rgba(99,102,241,0.2);
+  color: var(--accent-text);
+}
+.md-editor__btn:disabled { opacity: 0.4; cursor: not-allowed; }
+.md-editor__textarea {
+  background: var(--surface);
+  border: none;
+  border-radius: 0;
+  color: var(--text);
+  font: inherit;
+  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
+  font-size: 0.875rem;
+  line-height: 1.6;
+  padding: 0.875rem 1rem;
+  width: 100%;
+  resize: vertical;
+  min-height: 200px;
+  outline: none;
+}
+.md-editor__preview {
+  background: var(--surface);
+  min-height: 200px;
+  max-height: 480px;
+  overflow-y: auto;
+  padding: 1rem 1.25rem;
+}
+
 .template-preview .template-params-grid {
   display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
   gap: 0.6rem; margin: 0.75rem 0 1rem;