About the CSS_html/css_WEB-ITnose that is slowly emerging in the span style

The problem is stated in line 161 of the code. The main problem is that the text cannot appear properly and the code will be displayed together. I don’t know what happened.
This is the download address. I hope you can help me
http://pan.baidu.com/s/1eQnlxIi

Reply to discussion (solution)

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The problem is stated in line 161 of the code. The main problem is that the text cannot appear normally and the code will be displayed together. I don’t know what’s going on.
This is the download address, I hope you can help me
http://pan.baidu.com/s/1eQnlxIi

http://a7d.net46.net/music_visualization. php
You just need to remove the initial class attribute of h1 h2. Only when the attribute changes will there be a transition effect

<h1 id="h1"><span class="letter-14">3</span></h1><h2 id="h2"></h2>