body {
font-size: calc(21px + (26 - 14) * ((100vw - 300px) / (1600 - 300))) !important; }
header {
background-color: #D3D3D3; }
header nav {
display: flex;
height: 3em;
justify-content: flex-end; }
header nav ul {
display: flex;
align-items: center; }
header nav ul li {
display: flex;
align-items: center;
margin-right: 2em;
list-style: none; }
header nav ul li a {
text-decoration: none; }
header nav ul li a:hover {
text-decoration: none; }
.mail svg {
fill: #007bff;
height: 2em;
width: 2em;
transition: all .5s; }
.mail svg:hover {
fill: #0056b3; }
.container {
width: 80%;
padding-right: 15px;
padding-left: 15px;
margin-right: auto;
margin-left: auto; }
footer {
position: absolute;
left: 0;
bottom: 0;
width: 100%;
height: 3em;
background-color: #D3D3D3;
display: flex;
align-items: center;
justify-content: center; }
footer p {
display: flex; }
@media screen and (max-width: 1280px) {
.container {
width: 100%;
padding: 0 !important;
margin: 0 !important; } }
.modal {
opacity: 0;
visibility: hidden;
position: fixed;
top: 0;
right: 0;
bottom: 0;
left: 0;
text-align: left;
background: rgba(0, 0, 0, 0.9);
transition: opacity .25s ease; }
.modal__bg {
position: absolute;
top: 0;
right: 0;
bottom: 0;
left: 0;
cursor: pointer; }
.modal-state {
display: none; }
.modal-state:checked + .modal {
opacity: 1;
visibility: visible; }
.modal-state:checked + .modal .modal__inner {
top: 0; }
.modal__inner {
transition: top .25s ease;
position: absolute;
top: -20%;
right: 0;
bottom: 0;
left: 0;
width: 50%;
margin: auto;
overflow: auto;
background: #fff;
border-radius: 5px;
padding: 1em 2em;
height: 50%;
resize: both; }
.modal__close {
position: absolute;
right: 1em;
top: 1em;
width: 1.1em;
height: 1.1em;
cursor: pointer; }
.modal__close:after,
.modal__close:before {
content: '';
position: absolute;
width: 2px;
height: 1.5em;
background: #ccc;
display: block;
transform: rotate(45deg);
left: 50%;
margin: -3px 0 0 -1px;
top: 0; }
.modal__close:hover:after,
.modal__close:hover:before {
background: #aaa; }
.modal__close:before {
transform: rotate(-45deg); }
@media screen and (max-width: 768px) {
.modal__inner {
width: 90%;
height: 50%;
box-sizing: border-box; } }
<!DOCTYPE html>
<html lang="en">
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta charset="UTF-8">
<title>Title</title>
<link rel="stylesheet" href="css/reboot.css">
<link rel="stylesheet" href="css/main.css">
</head>
<body>
<header id="header " class="header">
<nav>
<ul>
<li><a href="#">Home</a></li>
<li><a href="#">Service</a></li>
<li><a href="" class="mail btn"><label for="modal-1">
<svg version="1.1" xmlns="http://www.w3.org/2000/svg"
x="0px" y="0px"
viewBox="0 0 14 14" style="enable-background:new 0 0 14 14;" xml:space="preserve">
<path d="M7,9L5.268,7.484l-4.952,4.245C0.496,11.896,0.739,12,1.007,12h11.986
c0.267,0,0.509-0.104,0.688-0.271L8.732,7.484L7,9z"/>
<path d="M13.684,2.271C13.504,2.103,13.262,2,12.993,2H1.007C0.74,2,0.498,2.104,0.318,2.273L7,8
L13.684,2.271z"/>
<polygon points="0,2.878 0,11.186 4.833,7.079 "/>
<polygon points="9.167,7.079 14,11.186 14,2.875 "/>
</svg>
</label> </a></li>
</ul>
</nav>
</header>
<div class="container">
<div class="content">
<div class="text"><p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Aliquam fuga illo ipsum
recusandae sapiente vero, voluptatum? Ad cum cupiditate dolor, et excepturi magnam quasi repellat
reprehenderit saepe similique soluta temporibus?</p>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Aliquam fuga illo ipsum
recusandae sapiente vero, voluptatum? Ad cum cupiditate dolor, et excepturi magnam quasi repellat
reprehenderit saepe similique soluta temporibus?</p></div>
</div>
</div>
<input class="modal-state" id="modal-1" type="checkbox"/>
<div class="modal">
<label class="modal__bg" for="modal-1"></label>
<div class="modal__inner">
<label class="modal__close" for="modal-1"></label>
<h2>Some Text</h2>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cum dolorem ducimus expedita id ipsum iste omnis ut? Beatae, blanditiis dicta, ea eaque fugiat in minima odit officia praesentium, vitae voluptas.</p>
</div>
</div>
<footer class="footer" id="footer">
<p>copyright 2019</p>
</footer>
</body>
</html>