diff --git a/README.md b/README.md
index 621bddd..37ea3a7 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,6 @@
-<div style="text-align:center"><img src="https://user-images.githubusercontent.com/5798442/103439598-9e952a00-4c81-11eb-881f-67c593bb7861.png" width="60%" height="60%" /></div>
+<p align="center">
+  <img src="https://user-images.githubusercontent.com/5798442/103439598-9e952a00-4c81-11eb-881f-67c593bb7861.png" width="75%" height="75%" />
+</p>
 
 ![Build Status](https://github.com/kojix2/youplot/workflows/test/badge.svg)
 [![Gem Version](https://badge.fury.io/rb/youplot.svg)](https://badge.fury.io/rb/youplot)