JSFiddle - React, Tailwind, and code Playground

HTML

<form>
  Pattern: <input type="text" value="120" pattern="[1][2][1]" title="Summe muss 100 ergeben">
      <br />
  Readonly: <input type="text" value="120" readonly>
      <br />    
  Pattern+Readonly:<input type="text" value="120" pattern="[1][2][1]" title="Summe muss 100 ergeben" readonly>
      <br />    
   Pattern+Disabled:<input type="text" value="120" pattern="[1][2][1]" title="Summe muss 100 ergeben" disabled>    
  <input type="submit">
</form>