Epic dark Vietnamese historical poster thumbnail, 16:9 horizontal 1920x1080. Subject: Lý Thường Kiệt, legendary Đại Việt commander of the Lý dynasty, dignified heroic portrait in 11th century Vietnamese armor, standing before the Như Nguyệt river defense line, smoky battlefield, Song army silhouettes in the distance, storm clouds, sepia bronze gold palette, parchment texture, black ink splash / grunge title panel, large gold Vietnamese brush-calligraphy title text: "LÝ THƯỜNG KIỆT". Subtitle small: "NHƯ NGUYỆT ĐẠI CHIẾN". Dramatic contrast, cinematic, culturally grounded Vietnamese Lý dynasty costume and weapons, no modern objects, no watermark, no logo, avoid wrong armor.