Simple web calculator: Buttons of the calculator

calculator-buttons.html

<section class="buttons grid">
  <button class="red" value="ac">AC</button>
  <button class="red" value="ce">ce</button>
  <button value="/">÷</button>
  <button value="*">x</button>

  <button value="7">7</button>
  <button value="8">8</button>
  <button value="9">9</button>
  <button value="-">-</button>

  <button value="4">4</button>
  <button value="5">5</button>
  <button value="6">6</button>
  <button value="+">+</button>

  <button value="1">1</button>
  <button value="2">2</button>
  <button value="3">3</button>
  <button class="equals" value="=">=</button>

  <button class="zero" value="0">0</button>
  <button value=".">.</button>
</section>