HTML, CSS and JavaScript playground

<!DOCTYPE html>
<html>
<head>
	<meta name="viewport" content="width=device-width">
	<meta charset="utf-8">
	<title>First Site By PHP</title>
	<link rel="stylesheet" type="text/css" href="style/main.css">
	<link rel="stylesheet" type="text/css" href="style/media.css">

</head>
<body>
	<div class="header">
		<div class="container">
			<ul class="menu">
				<li><a href="#about">About us</a></li>
				<li><a href="">Contacts</a></li>
				<li><a href="#advantages">Advantages</a></li>
				<li><a href="">Chat</a></li>
				<li><a href="">Sign In</a></li>
			</ul>
			<ul class="mob-menu">
				<li><a class="logo" href="">LOGO</a></li>
				<li class="toggle"><a href="#"><img src="data:image/svg+xml;base64,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"></a>
					<ul class="submenu">
						<li><a href="#about">About us</a></li>
						<li><a href="">Contacts</a></li>
						<li><a href="#advantages">Advantages</a></li>
						<li><a href="">Chat</a></li>
						<li><a href="">Sign In</a></li>
					</ul>
				</li>
				</ul>
		</div>
	</div>
</body>
</html>

@import url('https://fonts.googleapis.com/css?family=Lato|Roboto|Roboto+Mono|Anton|Libre+Baskerville&display=swap');
*{
	margin: 0;
	padding: 0;
}
html,body{
	overflow-x:hidden;
}
.container{
	width: 1050px;
	margin: 0 auto;
}
.first-block h1{
	padding-top: 20px;
	font-size: 50px;
	color: #565656;
	font-family: 'Roboto', sans-serif;
	text-align: center;
	margin-bottom: 150px;
}
.first-block{
	background-image: url("../images/pic-4.jpg");
	background-size: cover;
	background-attachment: fixed;
	background-position: center;
	background-repeat: no-repeat;
	height: 600px;
	text-align: center;

}
ul {
	list-style: none;
}
a{
	text-decoration: none;
}
.header, .footer{
	background: #000;
}

/* HEADER */
.menu{
	padding: 20px;
	text-align: center;
}
.menu a, .col a{
	color: #fff;
	font-family: 'Roboto Mono', sans-serif;
	font-size: 20px;
}
.menu a:hover, .col a:hover{
	color: lightblue;
	text-decoration: underline;
	transition: 1s;
}
.menu li{
	display: inline-block;
}
.menu li:not(:last-child){
	margin-right: 55px;
}

/* ---------- */

/* FOOTER */
.columns .col{
	padding: 0;
	margin: 0;
	display: inline-block;
	width: 300px;
	vertical-align: top;
}
.footer{
	padding: 40px 40px 10px 40px;
	text-align: center;
}
.columns{
	margin-bottom: 20px;
}
.rights{
	color: #656565;
}
.uvins{
	color: #656565;
	font-size: 16px;
}
.uvins:hover{
	color: #EDEDED;
	transition: 1s;
}

/* ---------------- */
.mob-menu{
	display: none;
	height: 30px;
	position: relative;
	width: 100%;
}
.mob-menu .logo{
	color: #fff;
	font-size: 25px;
	font-family: 'Roboto Mono', sans-serif;
	position: absolute;
	top: 13px;
	left: 30px;
}
.mob-menu .toggle{
	position: absolute;
	top: 16px;
	right: 60px;
}
/*.btn{

color: #EDEDED;
	padding: 20px;
	font-family: 'Lato', sans-serif;
	font-weight: bold;
	border-radius: 15px;
	background: #3186e8;
}
.btn:hover{
	background: blue;
	transition: 1s;
	text-decoration: underline;
*/
/* ABOUT US */

.first-section{
	margin-top: 50px;
	padding-bottom: 100px;
}
.section-header{
	font-family: 'Anton', sans-serif;
	font-size: 35px;
	overflow: hidden;
	
}
/* LINES before and after "ABOUT US" */
.section-header:before, .section-header:after{
	content: '';
	display: inline-block;
	vertical-align: middle;
	width: 10%;
	height: 3px;
	background: #565656;
	border: solid #FFF;
  	border-width: 0 10px;
}
.section-header:before{
	margin-left: -100%;
}
.section-header:after{
	margin-right: -100%;
}
.cols-about div{
	display: inline-block;
}
.cols-about{
	margin-top: 70px;
	margin-bottom: 30px;
}
.col-right{
	width: 450px;
	vertical-align: top;
	font-family: 'Roboto', sans-serif;
	font-weight: bold;
	font-size: 18px;
}
.col-left img{
	width: 325px;
	height: 325px;
	margin-right: 20px;
	border: 1px solid #000;
	border-radius: 50%;
}
.quote{
	margin-top: 40px;
	font-family: 'Roboto', cursive;
	color: #656565;
	font-style: italic;
	font-size: 20px;
}
#advantages{
	padding-top: 50px;
	background: #EDEDED;
	padding-bottom: 100px;
}
.items{
	margin-top: 70px;
	text-align: center;
}
.items .item{
	display: inline-block;
	width: 330px;
	vertical-align: top;
	text-align: center;
}
.items .item:not(:last-child){
	margin-right: 30px;
}
.item img{
	width: 200px;
	height: 200px;
	border-radius: 50%;
	border: 2px solid #565656;
	margin-bottom: 15px;
}
.name-item{
	font-family: 'Anton', sans-serif;
	font-size: 25px;
	color: #212121;
}
.text-item{
	font-family: 'Roboto', sans-serif;
	font-size: 18px;
	color: #565656;
}
.submenu{
  	position: absolute;
  	margin: 0;
  	top:44px;
  	margin: 0 -30px 0 60px;
  	right: 0px;
  	display: none;
}
.submenu a{
	color: #fff;
	font-family: 'Roboto Mono', sans-serif;
	font-size: 20px;
	padding: 10px 200px;
}
.submenu li{
	padding: 10px;
	border-bottom: 1px solid #656565;
	background: #000;
	padding: 10px -30% 10px -30%;

}
.submenu li:first-child{
	border-top:1px solid #656565;
}
.mob-menu > li:hover > ul.submenu{
	display: block;
}

@import url('https://fonts.googleapis.com/css?family=Lato|Roboto|Roboto+Mono&display=swap');
@media (max-width: 430px){
	.container{
		width: 100%;
		text-align: center;
	}
	.menu{
		display: none;
	}
	.mob-menu{
		display: block;
		width: 100%;
		padding: 15px;
	}
	.first-block h1{
		font-size: 40px;
	}
	.cols-about div{
		width: 100%;
		margin: 0 auto;	
	}
	.col-right p{
		font-size: 14px;
		width: 92%;
		margin: 30px 4% 0 4%;
	}
	.col-left img{
		margin-right: 0;
	}
	.quote, .col a{
		font-size: 15px;
	}
	.rights{
		font-size: 12px;
	}
	.items .item{
		width: 100%;
		margin: 0 auto;
		margin-bottom: 30px;
	}
	.items .item .text-item{
		width: 94%;
		margin: 0 3% 0 3%;
	}
	.submenu{
		position: absolute;
		right: -30px;
		top: 44px; 
	}
	
}
@media (max-width: 741px){
	.menu{
		display: none;
	}
	.mob-menu{
		display: block;
		width: 100%;
		padding: 15px;
	}
	.first-block h1{
		font-size: 40px;

}
	.firts-block{
		text-align: center;
	}
	.columns{
		display: block;
	}
}
@media (min-width: 431px) and (max-width: 799px) {
	.container{
		width: 100%;
		text-align: center;
	}
	.columns .col{
		width: 30%;
	}
	.items .item{
		width: 100%;
		margin: 0 auto;
		margin-bottom: 30px;
	}
	.items .item .text-item{
		width: 94%;
		margin: 0 3% 0 3%;
	}
}
@media (min-width: 742px){
	.container{
		width: 100%;
		text-align: center;
	}
	.columns .col{
		width: 25%;
	}
}