diff --git a/src/admin/components/PlanCellModal.tsx b/src/admin/components/PlanCellModal.tsx
new file mode 100644
index 0000000..618b96d
--- /dev/null
+++ b/src/admin/components/PlanCellModal.tsx
@@ -0,0 +1,390 @@
+import { useState } from "react";
+import FormModal from "./FormModal";
+import FormField from "./FormField";
+import AdminDatePicker from "./AdminDatePicker";
+import ConfirmModal from "./ConfirmModal";
+import { ResolvedCell } from "../lib/queries/plan";
+
+interface Project {
+  id: number;
+  name: string;
+}
+
+export type PlanCellModalMode =
+  | { kind: "closed" }
+  | { kind: "create"; userId: number; date: string }
+  | {
+      kind: "edit-range";
+      entryId: number;
+      userId: number;
+      date: string;
+      range: {
+        date_from: string;
+        date_to: string;
+        project_id: number | null;
+        category: string;
+        note: string;
+      };
+    }
+  | {
+      kind: "edit-override";
+      overrideId: number;
+      userId: number;
+      date: string;
+      cell: ResolvedCell;
+    }
+  | {
+      kind: "day-in-range";
+      entryId: number;
+      userId: number;
+      date: string;
+      range: {
+        date_from: string;
+        date_to: string;
+        project_id: number | null;
+        category: string;
+        note: string;
+      };
+    }
+  | { kind: "view"; userId: number; date: string; cell: ResolvedCell };
+
+interface Props {
+  open: boolean;
+  mode: PlanCellModalMode;
+  projects: Project[];
+  onClose: () => void;
+  onSaveEntry: (body: any) => Promise<void>;
+  onUpdateEntry: (id: number, body: any) => Promise<void>;
+  onDeleteEntry: (id: number) => Promise<void>;
+  onSaveOverride: (body: any) => Promise<void>;
+  onUpdateOverride: (id: number, body: any) => Promise<void>;
+  onDeleteOverride: (id: number) => Promise<void>;
+  onCreateOverrideFromRange: (
+    entryId: number,
+    userId: number,
+    date: string,
+  ) => Promise<void>;
+}
+
+const CATEGORIES = [
+  { value: "work", label: "Práce" },
+  { value: "preparation", label: "Příprava" },
+  { value: "travel", label: "Cesta / Montáž" },
+  { value: "leave", label: "Dovolená" },
+  { value: "sick", label: "Nemoc" },
+  { value: "training", label: "Školení" },
+  { value: "other", label: "Jiné" },
+];
+
+export default function PlanCellModal(props: Props) {
+  const { open, mode, onClose } = props;
+  if (!open || mode.kind === "closed") return null;
+  if (mode.kind === "view") return <ViewModal {...props} />;
+  if (mode.kind === "day-in-range")
+    return <DayInRangeModal {...props} mode={mode} />;
+  return <EditForm {...props} />;
+}
+
+function EditForm(props: Props) {
+  const {
+    mode,
+    onClose,
+    onSaveEntry,
+    onUpdateEntry,
+    onDeleteEntry,
+    onSaveOverride,
+    onUpdateOverride,
+    onDeleteOverride,
+    projects,
+  } = props;
+  const [submitting, setSubmitting] = useState(false);
+  const [confirmDelete, setConfirmDelete] = useState(false);
+
+  const isOverride = mode.kind === "edit-override";
+
+  const initial = (() => {
+    if (mode.kind === "create") {
+      return {
+        date_from: mode.date,
+        date_to: mode.date,
+        is_range: false,
+        project_id: null as number | null,
+        category: "work",
+        note: "",
+      };
+    }
+    if (mode.kind === "edit-range") {
+      return {
+        date_from: mode.range.date_from,
+        date_to: mode.range.date_to,
+        is_range: mode.range.date_from !== mode.range.date_to,
+        project_id: mode.range.project_id,
+        category: mode.range.category,
+        note: mode.range.note,
+      };
+    }
+    return {
+      date_from: mode.date,
+      date_to: mode.date,
+      is_range: false,
+      project_id: mode.cell.project_id,
+      category: mode.cell.category,
+      note: mode.cell.note,
+    };
+  })();
+
+  const [dateFrom, setDateFrom] = useState(initial.date_from);
+  const [dateTo, setDateTo] = useState(initial.date_to);
+  const [isRange, setIsRange] = useState(initial.is_range);
+  const [projectId, setProjectId] = useState<number | null>(initial.project_id);
+  const [category, setCategory] = useState(initial.category);
+  const [note, setNote] = useState(initial.note);
+
+  const title =
+    mode.kind === "create"
+      ? "Nový záznam plánu"
+      : mode.kind === "edit-range"
+        ? "Upravit rozsah"
+        : "Upravit přepsání dne";
+
+  const handleSubmit = async () => {
+    setSubmitting(true);
+    try {
+      if (mode.kind === "create") {
+        const userId = mode.userId;
+        await onSaveEntry({
+          user_id: userId,
+          date_from: dateFrom,
+          date_to: isRange ? dateTo : dateFrom,
+          project_id: projectId,
+          category,
+          note,
+        });
+      } else if (mode.kind === "edit-range") {
+        await onUpdateEntry(mode.entryId, {
+          date_from: dateFrom,
+          date_to: isRange ? dateTo : dateFrom,
+          project_id: projectId,
+          category,
+          note,
+        });
+      } else {
+        await onUpdateOverride(mode.overrideId, {
+          project_id: projectId,
+          category,
+          note,
+        });
+      }
+      onClose();
+    } finally {
+      setSubmitting(false);
+    }
+  };
+
+  const handleDelete = async () => {
+    setSubmitting(true);
+    try {
+      if (mode.kind === "edit-range") {
+        await onDeleteEntry(mode.entryId);
+      } else if (mode.kind === "edit-override") {
+        await onDeleteOverride(mode.overrideId);
+      }
+      onClose();
+    } finally {
+      setSubmitting(false);
+    }
+  };
+
+  return (
+    <>
+      <FormModal
+        isOpen
+        title={title}
+        onClose={onClose}
+        onSubmit={handleSubmit}
+        submitLabel={mode.kind === "create" ? "Vytvořit" : "Uložit"}
+        loading={submitting}
+      >
+        {mode.kind !== "create" && (
+          <div
+            style={{
+              marginBottom: 12,
+              display: "flex",
+              justifyContent: "flex-end",
+            }}
+          >
+            <button
+              type="button"
+              className="admin-btn admin-btn-danger"
+              onClick={() => setConfirmDelete(true)}
+              disabled={submitting}
+            >
+              Smazat
+            </button>
+          </div>
+        )}
+        <FormField label="Datum od">
+          <AdminDatePicker
+            value={dateFrom}
+            onChange={setDateFrom}
+            disabled={isOverride}
+          />
+        </FormField>
+        {!isOverride && (
+          <FormField label="Rozsah dnů">
+            <label>
+              <input
+                type="checkbox"
+                checked={isRange}
+                onChange={(e) => setIsRange(e.target.checked)}
+              />{" "}
+              Více dní
+            </label>
+          </FormField>
+        )}
+        {!isOverride && isRange && (
+          <FormField label="Datum do">
+            <AdminDatePicker value={dateTo} onChange={setDateTo} />
+          </FormField>
+        )}
+        <FormField label="Projekt">
+          <select
+            value={projectId ?? ""}
+            onChange={(e) =>
+              setProjectId(e.target.value ? Number(e.target.value) : null)
+            }
+          >
+            <option value="">— bez projektu —</option>
+            {projects.map((p) => (
+              <option key={p.id} value={p.id}>
+                {p.name}
+              </option>
+            ))}
+          </select>
+        </FormField>
+        <FormField label="Kategorie">
+          <select
+            value={category}
+            onChange={(e) => setCategory(e.target.value)}
+          >
+            {CATEGORIES.map((c) => (
+              <option key={c.value} value={c.value}>
+                {c.label}
+              </option>
+            ))}
+          </select>
+        </FormField>
+        <FormField label="Text poznámky" required>
+          <textarea
+            value={note}
+            onChange={(e) => setNote(e.target.value)}
+            maxLength={500}
+            rows={3}
+            required
+          />
+        </FormField>
+      </FormModal>
+
+      <ConfirmModal
+        isOpen={confirmDelete}
+        title="Smazat záznam plánu?"
+        message="Tato akce je nevratná (záznam bude soft-delete)."
+        confirmText="Smazat"
+        type="danger"
+        confirmVariant="danger"
+        loading={submitting}
+        onClose={() => setConfirmDelete(false)}
+        onConfirm={handleDelete}
+      />
+    </>
+  );
+}
+
+function DayInRangeModal(
+  props: Props & { mode: Extract<PlanCellModalMode, { kind: "day-in-range" }> },
+) {
+  const { mode, onClose, onCreateOverrideFromRange } = props;
+  return (
+    <FormModal
+      isOpen
+      title={`Den ${mode.date} je součástí rozsahu`}
+      onClose={onClose}
+      hideFooter
+    >
+      <p>
+        Tento den je součástí rozsahu:{" "}
+        <strong>
+          {mode.range.date_from} – {mode.range.date_to}
+        </strong>
+      </p>
+      <p>Co chcete udělat?</p>
+      <ul>
+        <li>
+          Upravit celý rozsah — klikněte na tlačítko níže nebo zavřete a
+          klikněte znovu na buňku v režimu editace rozsahu.
+        </li>
+        <li>
+          Upravit pouze tento den — vytvoří přepsání (override) pro toto datum.
+        </li>
+        <li>Zavřít — ponechá rozsah beze změny.</li>
+      </ul>
+      <div
+        style={{
+          marginTop: 12,
+          display: "flex",
+          gap: 8,
+          justifyContent: "flex-end",
+        }}
+      >
+        <button
+          type="button"
+          className="admin-btn admin-btn-secondary"
+          onClick={onClose}
+        >
+          Zavřít
+        </button>
+        <button
+          type="button"
+          className="admin-btn admin-btn-primary"
+          onClick={async () => {
+            await onCreateOverrideFromRange(
+              mode.entryId,
+              mode.userId,
+              mode.date,
+            );
+            onClose();
+          }}
+        >
+          Upravit pouze tento den
+        </button>
+      </div>
+    </FormModal>
+  );
+}
+
+function ViewModal(props: Props) {
+  const { mode, onClose } = props;
+  if (mode.kind !== "view") return null;
+  const c = mode.cell;
+  return (
+    <FormModal isOpen title="Detail plánu" onClose={onClose} hideFooter>
+      <p>
+        <strong>Datum:</strong> {c.shift_date}
+      </p>
+      <p>
+        <strong>Kategorie:</strong> {c.category}
+      </p>
+      <p>
+        <strong>Projekt:</strong> {c.project_id ?? "—"}
+      </p>
+      <p>
+        <strong>Text:</strong> {c.note}
+      </p>
+      {c.rangeFrom && c.rangeTo && (
+        <p>
+          <strong>Patří do rozsahu:</strong> {c.rangeFrom} – {c.rangeTo}
+        </p>
+      )}
+    </FormModal>
+  );
+}