<asp:Button ID="Button1" runat="server" Text="縦書きテスト" Style="transform: rotate(-90deg);" />
<asp:Button ID="Button2" runat="server" Text="縦書きテスト2" Style="transform: rotate(90deg);" />
<asp:Button ID="Button1" runat="server" Text="縦書きテスト" Style="transform: rotate(-90deg);" />
<asp:Button ID="Button2" runat="server" Text="縦書きテスト2" Style="transform: rotate(90deg);" />