<html><head> <style>div{ border: 2px solid gray; font-size:0;}button{width: 25%; height: 30px;}.clear{width: 50%; background-color: orange;}.submit{width: 50%; background-color: lightgreen;}p{text-align: right; font-size: 15px;}</style></head><body><h1>Calculator Interface</h1> <div> <p>0.</p><button>7</button><button>8</button><button>9</button><button>x</button> <button>4</button><button>5</button><button>6</button><button>/</button> <button>1</button><button>2</button><button>3</button><button>+</button> <button>.</button><button>0</button><button>%</button><button>_</button> <button class="clear">AC</button><button class="submit">=</button> </div></body></html>]]>