<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Calculator </title>
</head>
<!--CSS File-->
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
display: flex;
justify-content: center;
align-items: center;
min-height: 100vh;
background: #fffbd5; /* fallback for old browsers */
background: -webkit-linear-gradient(
to right,
#b20a2c,
#fffbd5
); /* Chrome 10-25, Safari 5.1-6 */
background: linear-gradient(
to right,
#b20a2c,
#fffbd5
); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
}
.container-first {
position: relative;
background: #0b8000;
border-radius: 6px;
overflow: hidden;
z-index: 10;
}
.container-first .calculator {
position: relative;
display: grid;
}
.container-first .calculator .value {
grid-column: span 4;
height: 140px;
width: 300px;
border: none;
padding-left: 1em;
font-size: 2.5em;
color: gold;
}
.container-first .calculator span {
display: grid;
height: 4.5em;
font-weight: 900;
color: rgb(255, 255, 255);
text-align: center;
align-items: center;
font-size: 20px;
user-select: none;
border-bottom: 4px solid rgba(255, 255, 255, 0.07);
border-right: 4px solid rgba(255, 255, 255, 0.07);
}
input[type="text"] {
color: rgb(255, 136, 0);
background-color: rgb(156, 40, 40);
}
<body>
<div class="container-first">
<form name="val" class="calculator">
<input type="text" class="value" name="ans" />
<span onclick="document.val.ans.value+='4'">4</span>
<span onclick="document.val.ans.value+='5'">5</span>
<span onclick="document.val.ans.value+='6'">6</span>
<span onclick="document.val.ans.value =eval(document.val.ans.value)">
=
</span>
<span onclick="document.val.ans.value+='7'">7</span>
<span onclick="document.val.ans.value+='8'">8</span>
<span onclick="document.val.ans.value+='9'">9</span>
<span onclick="document.val.ans.value+='-'">-</span>
<span onclick="document.val.ans.value+='1'">1</span>
<span onclick="document.val.ans.value+='2'">2</span>
<span onclick="document.val.ans.value+='3'">3</span>
<span onclick="document.val.ans.value+='/'">/</span>
<span onclick="document.val.ans.value+='0'">0</span>
<span onclick="document.val.ans.value=''">C</span>
<span onclick="document.val.ans.value+='*'">*</span>
<span onclick="document.val.ans.value+='00'">00</span>
<span onclick="document.val.ans.value+='+'">+</span>
</form>
</div>
</body>
</html>
<html>
<head>
<link rel="stylesheet" type="text/css" href="style.css">
<link href="https://fonts.googleapis.com/css?family=Open+Sans:600,700" rel="stylesheet">
<title>A simple calculator</title>
</head>
<body>
<div id="container">
<div id="calculator">
<div id="result">
<div id="history">
<p id="history-value"></p>
</div>
<div id="output">
<p id="output-value"></p>
</div>
</div>
<div id="keyboard">
<button class="operator" id="clear">C</button>
<button class="operator" id="backspace">CE</button>
<button class="operator" id="%">%</button>
<button class="operator" id="/">÷</button>
<button class="number" id="7">7</button>
<button class="number" id="8">8</button>
<button class="number" id="9">9</button>
<button class="operator" id="*">×</button>
<button class="number" id="4">4</button>
<button class="number" id="5">5</button>
<button class="number" id="6">6</button>
<button class="operator" id="-">-</button>
<button class="number" id="1">1</button>
<button class="number" id="2">2</button>
<button class="number" id="3">3</button>
<button class="operator" id="+">+</button>
<button class="empty" id="empty"></button>
<button class="number" id="0">0</button>
<button class="empty" id="empty"></button>
<button class="operator" id="=">=</button>
</div>
</div>
</div>
<script src="script.js"></script>
</body>
</html>