Index: frontend/src/app/admin/semesters/page.tsx
===================================================================
--- frontend/src/app/admin/semesters/page.tsx	(revision b8093a091d45f33bab33deb8ff2fffc4734972c0)
+++ frontend/src/app/admin/semesters/page.tsx	(revision b8093a091d45f33bab33deb8ff2fffc4734972c0)
@@ -0,0 +1,173 @@
+"use client";
+
+import { useCallback, useEffect, useState } from "react";
+import { useTranslation } from "react-i18next";
+import { adminGet, adminSend, type AdminSemester } from "@/lib/admin-api";
+
+export default function AdminSemestersPage() {
+  const { t } = useTranslation();
+
+  const [semesters, setSemesters] = useState<AdminSemester[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [busy, setBusy] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [notice, setNotice] = useState<string | null>(null);
+
+  const [year, setYear] = useState(new Date().getFullYear());
+  const [type, setType] = useState<"winter" | "summer">("winter");
+  const [expandedId, setExpandedId] = useState<number | null>(null);
+
+  const refresh = useCallback(async () => {
+    setLoading(true);
+    setError(null);
+    try {
+      setSemesters(await adminGet<AdminSemester[]>("/api/admin/semesters"));
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e));
+    } finally {
+      setLoading(false);
+    }
+  }, []);
+
+  useEffect(() => {
+    void refresh();
+  }, [refresh]);
+
+  async function create() {
+    setBusy(true);
+    setError(null);
+    setNotice(null);
+    try {
+      const result = await adminSend("/api/admin/semesters", "POST", { Year: year, Type: type });
+      setNotice(result.message ?? null);
+      await refresh();
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e));
+    } finally {
+      setBusy(false);
+    }
+  }
+
+  return (
+    <div className="min-h-screen pb-8">
+      <div className="bg-primary text-white rounded-xl p-8 mb-8">
+        <h1 className="text-3xl font-bold mb-2">{t("admin_semesters")}</h1>
+        <p className="text-lg opacity-90">{t("admin_semesters_intro")}</p>
+      </div>
+
+      {error && (
+        <div className="mb-4 rounded-lg border border-red-200 bg-red-50 px-4 py-3 text-sm text-red-800">{error}</div>
+      )}
+      {notice && (
+        <div className="mb-4 rounded-lg border border-green-200 bg-green-50 px-4 py-3 text-sm text-green-800">{notice}</div>
+      )}
+
+      <div className="bg-card rounded-xl shadow-sm border border-border p-6 mb-6">
+        <h2 className="text-xl font-semibold mb-4 text-card-foreground">{t("admin_new_semester")}</h2>
+        <div className="flex flex-wrap items-end gap-4">
+          <label className="flex flex-col">
+            <span className="text-sm text-muted-foreground">{t("admin_year")}</span>
+            <input
+              type="number"
+              min={2000}
+              max={2100}
+              className="rounded-lg border border-border bg-background px-3 py-2"
+              value={year}
+              onChange={(e) => setYear(Number(e.target.value))}
+            />
+          </label>
+          <label className="flex flex-col">
+            <span className="text-sm text-muted-foreground">{t("admin_type")}</span>
+            <select
+              className="rounded-lg border border-border bg-background px-3 py-2"
+              value={type}
+              onChange={(e) => setType(e.target.value as "winter" | "summer")}
+            >
+              <option value="winter">{t("admin_winter")}</option>
+              <option value="summer">{t("admin_summer")}</option>
+            </select>
+          </label>
+          <button
+            disabled={busy}
+            className="rounded-lg bg-primary px-4 py-2 text-sm font-medium text-white disabled:opacity-50"
+            onClick={() => void create()}
+          >
+            {t("admin_open_semester")}
+          </button>
+        </div>
+      </div>
+
+      <div className="bg-card rounded-xl shadow-sm border border-border overflow-hidden">
+        <div className="bg-primary text-white px-6 py-4">
+          <h2 className="text-xl font-bold">{t("admin_open_semesters")}</h2>
+        </div>
+        <div className="overflow-x-auto">
+          <table className="w-full">
+            <thead className="bg-accent">
+              <tr>
+                <th className="px-4 py-3 text-left text-xs font-medium uppercase text-muted-foreground">{t("semester")}</th>
+                <th className="px-4 py-3 text-left text-xs font-medium uppercase text-muted-foreground">{t("admin_enrolments")}</th>
+                <th className="px-4 py-3 text-left text-xs font-medium uppercase text-muted-foreground">{t("admin_coverage")}</th>
+                <th className="px-4 py-3 text-left text-xs font-medium uppercase text-muted-foreground">{t("actions")}</th>
+              </tr>
+            </thead>
+            <tbody>
+              {loading ? (
+                <tr><td className="px-4 py-4 text-muted-foreground" colSpan={4}>{t("loading")}</td></tr>
+              ) : semesters.length === 0 ? (
+                <tr><td className="px-4 py-4 text-muted-foreground" colSpan={4}>{t("admin_no_semesters")}</td></tr>
+              ) : (
+                semesters.map((s) => {
+                  const uncovered = s.uncoveredSubjects.length;
+                  return (
+                    <>
+                      <tr key={s.id} className="hover:bg-accent">
+                        <td className="px-4 py-3 border-b text-card-foreground">{s.name}</td>
+                        <td className="px-4 py-3 border-b text-card-foreground">{s.enrolmentCount}</td>
+                        <td className="px-4 py-3 border-b">
+                          {uncovered === 0 ? (
+                            <span className="rounded-full bg-green-100 px-2 py-0.5 text-xs text-green-800">
+                              {t("admin_fully_covered")}
+                            </span>
+                          ) : (
+                            <span className="rounded-full bg-yellow-100 px-2 py-0.5 text-xs text-yellow-900">
+                              {t("admin_uncovered_count", { count: uncovered })}
+                            </span>
+                          )}
+                        </td>
+                        <td className="px-4 py-3 border-b">
+                          {uncovered > 0 && (
+                            <button
+                              className="rounded-lg border border-border px-3 py-1.5 text-sm"
+                              onClick={() => setExpandedId(expandedId === s.id ? null : s.id)}
+                            >
+                              {expandedId === s.id ? t("admin_close") : t("admin_show_uncovered")}
+                            </button>
+                          )}
+                        </td>
+                      </tr>
+                      {expandedId === s.id && uncovered > 0 && (
+                        <tr key={`${s.id}-detail`}>
+                          <td colSpan={4} className="border-b bg-accent/40 px-4 py-4 text-sm">
+                            <p className="mb-2 text-muted-foreground">{t("admin_uncovered_hint")}</p>
+                            <ul className="grid gap-1 sm:grid-cols-2 lg:grid-cols-3">
+                              {s.uncoveredSubjects.map((u) => (
+                                <li key={u.id} className="text-card-foreground">
+                                  <span className="font-mono">{u.code}</span> — {u.name}
+                                </li>
+                              ))}
+                            </ul>
+                          </td>
+                        </tr>
+                      )}
+                    </>
+                  );
+                })
+              )}
+            </tbody>
+          </table>
+        </div>
+      </div>
+    </div>
+  );
+}