diff --git a/src/admin/components/PlanCategoriesModal.tsx b/src/admin/components/PlanCategoriesModal.tsx
new file mode 100644
index 0000000..6852125
--- /dev/null
+++ b/src/admin/components/PlanCategoriesModal.tsx
@@ -0,0 +1,145 @@
+import { useState } from "react";
+import FormModal from "./FormModal";
+import { useApiMutation } from "../lib/queries/mutations";
+import { useAlert } from "../context/AlertContext";
+import { PlanCategory } from "../lib/queries/plan";
+
+interface Props {
+  isOpen: boolean;
+  onClose: () => void;
+  categories: PlanCategory[];
+}
+
+const DEFAULT_NEW_COLOR = "#2563eb";
+
+export default function PlanCategoriesModal({
+  isOpen,
+  onClose,
+  categories,
+}: Props) {
+  const alert = useAlert();
+  const [newLabel, setNewLabel] = useState("");
+  const [newColor, setNewColor] = useState(DEFAULT_NEW_COLOR);
+
+  const createCat = useApiMutation<
+    { label: string; color: string },
+    PlanCategory
+  >({
+    url: "/api/admin/plan/categories",
+    method: "POST",
+    invalidate: ["plan", "dashboard", "audit-log"],
+  });
+  const updateCat = useApiMutation<
+    { id: number; label?: string; color?: string; is_active?: boolean },
+    PlanCategory
+  >({
+    url: (v) => `/api/admin/plan/categories/${v.id}`,
+    method: "PATCH",
+    invalidate: ["plan", "dashboard", "audit-log"],
+  });
+
+  const handleAdd = () => {
+    const label = newLabel.trim();
+    if (!label) {
+      alert.error("Zadejte název kategorie");
+      return;
+    }
+    createCat.mutate(
+      { label, color: newColor },
+      {
+        onSuccess: () => {
+          setNewLabel("");
+          setNewColor(DEFAULT_NEW_COLOR);
+        },
+        onError: (e) => alert.error(e.message),
+      },
+    );
+  };
+
+  const patch = (
+    id: number,
+    body: { label?: string; color?: string; is_active?: boolean },
+  ) => {
+    updateCat.mutate(
+      { id, ...body },
+      { onError: (e) => alert.error(e.message) },
+    );
+  };
+
+  const busy = createCat.isPending || updateCat.isPending;
+
+  return (
+    <FormModal
+      isOpen={isOpen}
+      onClose={onClose}
+      title="Správa kategorií"
+      hideFooter
+      size="md"
+    >
+      <div className="plan-cat-manager">
+        {categories.map((c) => (
+          <div
+            key={c.id}
+            className={`plan-cat-row${c.is_active ? "" : " plan-cat-row--inactive"}`}
+          >
+            <input
+              type="color"
+              className="plan-cat-color"
+              value={c.color}
+              disabled={busy}
+              onChange={(e) => patch(c.id, { color: e.target.value })}
+              aria-label={`Barva – ${c.label}`}
+            />
+            <input
+              type="text"
+              className="admin-form-input"
+              defaultValue={c.label}
+              disabled={busy}
+              onBlur={(e) => {
+                const v = e.target.value.trim();
+                if (v && v !== c.label) patch(c.id, { label: v });
+              }}
+              aria-label={`Název – ${c.label}`}
+            />
+            <button
+              type="button"
+              className="admin-btn admin-btn-secondary admin-btn-sm"
+              disabled={busy}
+              onClick={() => patch(c.id, { is_active: !c.is_active })}
+            >
+              {c.is_active ? "Skrýt" : "Obnovit"}
+            </button>
+          </div>
+        ))}
+
+        <div className="plan-cat-row plan-cat-row--new">
+          <input
+            type="color"
+            className="plan-cat-color"
+            value={newColor}
+            disabled={busy}
+            onChange={(e) => setNewColor(e.target.value)}
+            aria-label="Barva nové kategorie"
+          />
+          <input
+            type="text"
+            className="admin-form-input"
+            placeholder="Nová kategorie…"
+            value={newLabel}
+            disabled={busy}
+            onChange={(e) => setNewLabel(e.target.value)}
+            onKeyDown={(e) => e.key === "Enter" && handleAdd()}
+          />
+          <button
+            type="button"
+            className="admin-btn admin-btn-primary admin-btn-sm"
+            disabled={busy}
+            onClick={handleAdd}
+          >
+            Přidat
+          </button>
+        </div>
+      </div>
+    </FormModal>
+  );
+}
diff --git a/src/admin/pages/PlanWork.tsx b/src/admin/pages/PlanWork.tsx
index de344fb..823a1d5 100644
--- a/src/admin/pages/PlanWork.tsx
+++ b/src/admin/pages/PlanWork.tsx
@@ -11,6 +11,7 @@ import {
 import type { PlanCellModalMode } from "../components/PlanCellModal";
 import PlanGrid from "../components/PlanGrid";
 import PlanCellModal from "../components/PlanCellModal";
+import PlanCategoriesModal from "../components/PlanCategoriesModal";
 import Forbidden from "../components/Forbidden";
 import { projectListOptions, type Project } from "../lib/queries/projects";
 import { planCategoriesOptions, type PlanCategory } from "../lib/queries/plan";
@@ -129,6 +130,8 @@ export default function PlanWork() {
   const { data: categoriesData } = useQuery(planCategoriesOptions());
   const categories: PlanCategory[] = categoriesData ?? [];
 
+  const [catModalOpen, setCatModalOpen] = useState(false);
+
   // `lastMutated` is the (userId, date) of the most recent successful
   // mutation. We pass it to PlanGrid as `pulseKey`; the matching cell
   // gets a one-shot CSS pulse animation. We clear it after 700ms (the
@@ -638,6 +641,15 @@ export default function PlanWork() {
             Měsíc
           </button>
         </div>
+        {canEdit && (
+          <button
+            type="button"
+            className="admin-btn admin-btn-secondary"
+            onClick={() => setCatModalOpen(true)}
+          >
+            Správa kategorií
+          </button>
+        )}
       </motion.div>
 
       {gridLoading && (
@@ -695,6 +707,11 @@ export default function PlanWork() {
         onCreateOverrideFromRange={createOverrideFromRange}
         onSwitchToEditRange={switchToEditRange}
       />
+      <PlanCategoriesModal
+        isOpen={catModalOpen}
+        onClose={() => setCatModalOpen(false)}
+        categories={categories}
+      />
     </div>
   );
 }
diff --git a/src/admin/plan.css b/src/admin/plan.css
index 25293cd..b7800b7 100644
--- a/src/admin/plan.css
+++ b/src/admin/plan.css
@@ -977,3 +977,37 @@
     animation: none !important;
   }
 }
+
+/* Category manager modal rows */
+.plan-cat-manager {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+.plan-cat-row {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+.plan-cat-row--inactive {
+  opacity: 0.55;
+}
+.plan-cat-row .admin-form-input {
+  flex: 1;
+  min-width: 0;
+}
+.plan-cat-color {
+  width: 34px;
+  height: 34px;
+  padding: 0;
+  border: 1px solid var(--plan-paper-rule);
+  border-radius: 6px;
+  background: none;
+  cursor: pointer;
+  flex: 0 0 auto;
+}
+.plan-cat-row--new {
+  margin-top: 6px;
+  padding-top: 10px;
+  border-top: 1px dashed var(--plan-paper-rule);
+}