.bgm img{ width: 100%; height: 100%; } .btn { position: absolute; left: 50%; bottom: .55rem; transform: translateX(-50%); width: 2.83rem; height: .72rem; background: #E40006; border-radius: .12rem; text-align: center; line-height: .72rem; color: #fff; font-size: .36rem; font-weight: bold; }