function checkAdminAccess() {
    const loggedInUser = JSON.parse(sessionStorage.getItem("current_user"));
    if (!loggedInUser || loggedInUser.role !== "admin") {
        alert("Access Denied: Admins Only");
        window.location.href = "index.html";
    }
}

function promoteToAdmin(targetId) {
    if (targetId === 1) return; // Cannot modify karblock
    let data = JSON.parse(localStorage.getItem(DB_NAME));
    const userIndex = data.users.findIndex(u => u.id === targetId);
    if (userIndex !== -1) {
        data.users[userIndex].role = "admin";
        localStorage.setItem(DB_NAME, JSON.stringify(data));
        location.reload();
    }
}