diff --git a/src/features/notes/NotesApp.tsx b/src/features/notes/NotesApp.tsx
index 3f24a21..2b3db8b 100644
--- a/src/features/notes/NotesApp.tsx
+++ b/src/features/notes/NotesApp.tsx
@@ -85,6 +85,16 @@ export function NotesApp() {
     setSnippets(prev => prev.filter(x => x.id !== id));
   }, []);
 
+  const { snippetColumnLeft, snippetColumnRight } = useMemo(() => {
+    const left: Snippet[] = [];
+    const right: Snippet[] = [];
+    snippets.forEach((s, i) => {
+      if (i % 2 === 0) left.push(s);
+      else right.push(s);
+    });
+    return { snippetColumnLeft: left, snippetColumnRight: right };
+  }, [snippets]);
+
   const createNew = async () => {
     setError(null);
     try {
@@ -105,7 +115,7 @@ export function NotesApp() {
   };
 
   return (
-    <div className="mx-auto flex w-full max-w-6xl flex-col gap-4 px-4 py-4 sm:px-5">
+    <div className="mx-auto flex w-full max-w-6xl flex-col gap-4 px-4 py-4 sm:px-5 xl:max-w-7xl min-[1800px]:max-w-none min-[1800px]:px-6 min-[2200px]:px-10">
       <NotesToolbar
         query={query}
         onQueryChange={setQuery}
@@ -128,21 +138,52 @@ export function NotesApp() {
       {error ? <p className="text-sm text-destructive">{error}</p> : null}
       {loading ? <p className="text-sm text-muted-foreground">Lade Snippets …</p> : null}
 
-      <div className="flex flex-col gap-2 sm:gap-2.5">
-        {!loading && snippets.length === 0 ? (
-          <p className="text-center text-sm text-muted-foreground">Keine Snippets. Mit „Neu“ starten.</p>
-        ) : null}
-        {snippets.map(s => (
-          <SnippetCard
-            key={s.id}
-            snippet={s}
-            treeColorByName={treeColorByName}
-            treeDisplayByName={treeDisplayByName}
-            onReplace={replaceSnippet}
-            onRemove={removeSnippet}
-          />
-        ))}
-      </div>
+      {!loading && snippets.length === 0 ? (
+        <p className="text-center text-sm text-muted-foreground">Keine Snippets. Mit „Neu“ starten.</p>
+      ) : null}
+
+      {snippets.length > 0 ? (
+        <>
+          <div className="flex flex-col gap-2 sm:gap-2.5 min-[1800px]:hidden">
+            {snippets.map(s => (
+              <SnippetCard
+                key={s.id}
+                snippet={s}
+                treeColorByName={treeColorByName}
+                treeDisplayByName={treeDisplayByName}
+                onReplace={replaceSnippet}
+                onRemove={removeSnippet}
+              />
+            ))}
+          </div>
+          <div className="hidden min-[1800px]:flex min-[1800px]:flex-row min-[1800px]:items-start min-[1800px]:gap-x-8">
+            <div className="flex min-w-0 flex-1 flex-col gap-4">
+              {snippetColumnLeft.map(s => (
+                <SnippetCard
+                  key={s.id}
+                  snippet={s}
+                  treeColorByName={treeColorByName}
+                  treeDisplayByName={treeDisplayByName}
+                  onReplace={replaceSnippet}
+                  onRemove={removeSnippet}
+                />
+              ))}
+            </div>
+            <div className="flex min-w-0 flex-1 flex-col gap-4">
+              {snippetColumnRight.map(s => (
+                <SnippetCard
+                  key={s.id}
+                  snippet={s}
+                  treeColorByName={treeColorByName}
+                  treeDisplayByName={treeDisplayByName}
+                  onReplace={replaceSnippet}
+                  onRemove={removeSnippet}
+                />
+              ))}
+            </div>
+          </div>
+        </>
+      ) : null}
     </div>
   );
 }
diff --git a/src/server/db.ts b/src/server/db.ts
index 31a7a3f..085e841 100644
--- a/src/server/db.ts
+++ b/src/server/db.ts
@@ -2,55 +2,9 @@ import { Database } from "bun:sqlite";
 import { mkdirSync } from "fs";
 import path from "path";
 
-let dbInstance: Database | null = null;
+import { migrate } from "./db/migrate";
 
-function migrate(database: Database) {
-  database.run(`
-    CREATE TABLE IF NOT EXISTS snippets (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      title TEXT,
-      body TEXT NOT NULL DEFAULT '',
-      sort_order INTEGER NOT NULL DEFAULT 0,
-      created_at TEXT NOT NULL,
-      updated_at TEXT NOT NULL
-    );
-  `);
-  database.run(`
-    CREATE TABLE IF NOT EXISTS tags (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      name TEXT NOT NULL UNIQUE COLLATE NOCASE
-    );
-  `);
-  database.run(`
-    CREATE TABLE IF NOT EXISTS snippet_tags (
-      snippet_id INTEGER NOT NULL REFERENCES snippets(id) ON DELETE CASCADE,
-      tag_id INTEGER NOT NULL REFERENCES tags(id) ON DELETE CASCADE,
-      PRIMARY KEY (snippet_id, tag_id)
-    );
-  `);
-  database.run(`
-    CREATE TABLE IF NOT EXISTS tag_tree_nodes (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      name TEXT NOT NULL UNIQUE COLLATE NOCASE,
-      parent_id INTEGER REFERENCES tag_tree_nodes(id) ON DELETE CASCADE,
-      color TEXT,
-      label_prefix TEXT
-    );
-  `);
-  try {
-    database.run(`ALTER TABLE tag_tree_nodes ADD COLUMN label_prefix TEXT`);
-  } catch {
-    /* Spalte existiert bereits */
-  }
-  database.run(`CREATE INDEX IF NOT EXISTS idx_tag_tree_parent ON tag_tree_nodes(parent_id);`);
-  database.run(`CREATE INDEX IF NOT EXISTS idx_snippets_updated ON snippets(updated_at);`);
-  try {
-    database.run(`ALTER TABLE snippets ADD COLUMN deadline_at TEXT`);
-  } catch {
-    /* Spalte existiert bereits */
-  }
-  database.run(`CREATE INDEX IF NOT EXISTS idx_snippets_deadline ON snippets(deadline_at);`);
-}
+let dbInstance: Database | null = null;
 
 export function getDb(): Database {
   if (dbInstance) return dbInstance;
diff --git a/src/server/db/migrate.ts b/src/server/db/migrate.ts
new file mode 100644
index 0000000..65f6638
--- /dev/null
+++ b/src/server/db/migrate.ts
@@ -0,0 +1,75 @@
+import type { Database } from "bun:sqlite";
+
+/**
+ * Einmaliges Kernschema — so, als würde eine leere DB zum ersten Mal angelegt.
+ * `CREATE TABLE IF NOT EXISTS` ändert bestehende Tabellen nicht; fehlende Spalten
+ * werden danach idempotent per `ensureColumn` nachgezogen (bestehende Zeilen bleiben).
+ */
+
+function assertSqlIdent(name: string, label: string): void {
+  if (!/^[a-z][a-z0-9_]*$/i.test(name)) {
+    throw new Error(`${label} ist kein gültiger SQL-Identifier: ${name}`);
+  }
+}
+
+function tableHasColumn(database: Database, table: string, column: string): boolean {
+  assertSqlIdent(table, "Tabellenname");
+  assertSqlIdent(column, "Spaltenname");
+  const cols = database.query(`PRAGMA table_info(${table})`).all() as { name: string }[];
+  return cols.some(c => c.name === column);
+}
+
+/** Fügt eine Spalte nur hinzu, wenn sie noch fehlt (keine Exceptions als Steuerung). */
+function ensureColumn(database: Database, table: string, column: string, sqlType: string): void {
+  if (tableHasColumn(database, table, column)) return;
+  assertSqlIdent(table, "Tabellenname");
+  assertSqlIdent(column, "Spaltenname");
+  database.run(`ALTER TABLE ${table} ADD COLUMN ${column} ${sqlType}`);
+}
+
+export function migrate(database: Database): void {
+  database.run(`
+    CREATE TABLE IF NOT EXISTS snippets (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      title TEXT,
+      body TEXT NOT NULL DEFAULT '',
+      sort_order INTEGER NOT NULL DEFAULT 0,
+      created_at TEXT NOT NULL,
+      updated_at TEXT NOT NULL,
+      deadline_at TEXT
+    );
+  `);
+
+  database.run(`
+    CREATE TABLE IF NOT EXISTS tags (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      name TEXT NOT NULL UNIQUE COLLATE NOCASE
+    );
+  `);
+
+  database.run(`
+    CREATE TABLE IF NOT EXISTS snippet_tags (
+      snippet_id INTEGER NOT NULL REFERENCES snippets(id) ON DELETE CASCADE,
+      tag_id INTEGER NOT NULL REFERENCES tags(id) ON DELETE CASCADE,
+      PRIMARY KEY (snippet_id, tag_id)
+    );
+  `);
+
+  database.run(`
+    CREATE TABLE IF NOT EXISTS tag_tree_nodes (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      name TEXT NOT NULL UNIQUE COLLATE NOCASE,
+      parent_id INTEGER REFERENCES tag_tree_nodes(id) ON DELETE CASCADE,
+      color TEXT,
+      label_prefix TEXT
+    );
+  `);
+
+  /* Bestehende Installationen: Tabellen schon da, einzelne Spalten fehlen → ALTER nur bei Bedarf */
+  // ensureColumn(database, "snippets", "deadline_at", "TEXT");
+  // ensureColumn(database, "tag_tree_nodes", "label_prefix", "TEXT");
+
+  database.run(`CREATE INDEX IF NOT EXISTS idx_tag_tree_parent ON tag_tree_nodes(parent_id);`);
+  database.run(`CREATE INDEX IF NOT EXISTS idx_snippets_updated ON snippets(updated_at);`);
+  database.run(`CREATE INDEX IF NOT EXISTS idx_snippets_deadline ON snippets(deadline_at);`);
+}