A small problem with css_Basic Tutorial

Let me ask you a question
I want the following table to use table class=a class name to achieve the following effect
That is, I want to define a class in css and put cellspacing=1 bgcolor in table =#D0DDE5 and
bgcolor=#FFFFFF in td are both written into a class in css. Then I only need to use table class to implement it.
Please teach me

<table width="100%" cellspacing="1" bgcolor="#D0DDE5"> <tr> <td bgcolor="#FFFFFF">I want to write cellspacing=1 bgcolor=#D0DDE5 in table and bgcolor=#FFFFFF in td into a css class. How to write it</td> </tr> </table>
[Ctrl A Select All Note: If you need to introduce external Js, you need to refresh it before executing it]

<style type="text/css"> .tablecss{ border:1px solid #D0DDE5; } </style> <table width="100%" class="tablecss"> <tr> <td bgcolor="#FFFFFF">I want cellspacing=1 in table bgcolor=#D0DDE5 and bgcolor=#FFFFFF in td are both written into a class in css. How? Write</td> </tr> </table>
[Ctrl A select all Note: If you need to introduce external Js, you need to refresh it before executing it]