diff --git a/static/img/book_cover.png b/static/img/book_cover.png
index 8a3d0c8..33f0c84 100644
Binary files a/static/img/book_cover.png and b/static/img/book_cover.png differ
diff --git a/static/img/book_cover_zh-cn.png b/static/img/book_cover_zh-cn.png
index e78943d..925cabd 100644
Binary files a/static/img/book_cover_zh-cn.png and b/static/img/book_cover_zh-cn.png differ
diff --git a/static/img/logo.png b/static/img/logo.png
index bf934a5..32c221b 100644
Binary files a/static/img/logo.png and b/static/img/logo.png differ