html, body {
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
html {
    background-color: rgb(81, 172, 73);
}
header {
    width: auto;
    height: 60px;
    display: grid;
    background: #2ba550fe;
    margin: auto;
}
.botoninicio {
	background-color: #108d76;
	color: #fff;
	width: 200px;
	height: 50px;
	margin-top: 30px;
	border-radius: 10% / 50%;
	font-weight: bold;
}

.botoninicio:hover {
	background-color: #fff;
	color: #108d76;
	font-weight: bold;
}

div#titulo {
    font-size: 19px;
    color: #FFF;
    display: grid;
    margin: 0;
    margin-top: 18px;
    text-align: center;
}
hr {
    margin-top: -25px;
    margin-bottom: 40px;
}
body {
    width: 82.5%;
    margin: 0 auto;
    padding: 0.5em;
    background-color: rgba(255, 255, 255, 0.85);
}
div#caja {
    text-align: center;
    width: 50%;
    margin: 1em auto;
    padding-bottom: 1.5em;
    border: double 5px #fff;
    border-radius: 3% 3% 3% 3%;
    box-shadow: 1px 1px 5px 5px rgba(25, 25, 25, 0.65);
    background-color: rgba(255, 255, 255, 0.85);
}
h1 {
    font-size: 2.05em;
    color: rgb(33, 26, 241);
    margin-bottom: 1em;
}
input#pantalla {
    width: 80%;
    text-align: right;
    font: bold 1.45em monospace;
    margin: 0 auto;
    padding: 0.5em;
    background-color: rgba(191, 191, 183, 0.95);
    border: solid 2px #999;
    border-radius: 0.2em;
}
h2.grande {
    font-size: 1.65em;
    color: rgb(48, 39, 45);
    margin: 1.25em 0;
}
h3.separador {
    font-size: 1.25em;
    color: rgb(55, 105, 225);
    margin-top: 1.5em;
}
button {
    font: bold 1.05em serif;
    margin-right: 1em;
    padding: 0.5em 1.15em;
    border: solid 2px #fff;
    border-radius: 0.5em;
    background-color: rgba(79, 225, 96, 0.8);
    box-shadow: 1px 1px 0 5px rgba(200, 200, 200, 0.75);
}
button:hover {
    color: #fff;
    background-color: rgba(82, 84, 73, 0.9);
    border: dotted 2px #222;
}
footer {
    font-size: 18px;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
	color: #000000;
    background-color: rgba(125, 186, 19, 0.75);
    margin-top: 1.5em;
	padding: 0.75em;
	text-align: center;
}