title: How to get FLAT relief Entry widget in python ttk?
body: <p>I am writing a GUI FTP client app in python ttk. I can't seem to get the text Entries the way I wanted them to.<img src="https://i.stack.imgur.com/F3GI5.png" alt="enter image description here"></p>
  
  <p>The text Entries have the "SUNKEN" effect. I want to adjust the height and get the text entries to have a "FLAT" look, more like this program:<br/><br/>
  <a href="https://i.stack.imgur.com/PgztX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/PgztX.png" alt="enter image description here"></a>
  <br/>
  I got the buttons to look flat from <a href="https://stackoverflow.com/questions/40990704/how-get-no-border-effect-in-tkinter-ttk">here</a>, I am struggling to get the Entries to look flat.<br/>
  How do I get the Entries to look flat?<br/><br/>
  I don't want a tk solution, I know how to set relief FLAT in tk.</p>