Live Demo: Bootstrap Simple Navbar with Search Box

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<title>Bootstrap Simple Navbar with Search Box</title>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Raleway|Open+Sans">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css">
<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
<script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js"></script>
<style>
body {
	background: #eeeeee;
	font-family: 'Open Sans', sans-serif;
}
.navbar {
	font-size: 14px;
	background: #fff;
	padding-left: 16px;
	padding-right: 16px;
	border-bottom: 1px solid #d6d6d6;
	box-shadow: 0 0 4px rgba(0,0,0,.1);		
}
.navbar .navbar-brand {
	color: #555;
	padding-left: 0;
	font-size: 20px;
	padding-right: 50px;
	font-family: 'Raleway', sans-serif;
	text-transform: uppercase;
}
.navbar .navbar-brand b {
	color: #f04f01;
}
.navbar .navbar-nav a {
	font-size: 96%;
	font-weight: bold;		
	text-transform: uppercase;
}
.navbar .navbar-nav a.active {
	color: #f04f01 !important;
	background: transparent !important;
}
.search-box input.form-control, .search-box .btn {
	font-size: 14px;
	border-radius: 2px !important;
}
.search-box .input-group-append {
	padding-left: 4px;		
}
.search-box input.form-control:focus {
	border-color: #f04f01;
	box-shadow: 0 0 8px rgba(240,79,1,0.2);
}
.search-box .btn-danger, .search-box .btn-danger:active {
	font-weight: bold;
	background: #f04f01 !important;
	border-color: #f04f01;
	text-transform: uppercase;
	min-width: 90px;
}
.search-box .btn-danger:hover, .search-box .btn-danger:focus {
	background: #eb4e01 !important;
	box-shadow: 0 0 8px rgba(240,79,1,0.2);
}
.search-box .btn span {
	transform: scale(0.9);
	display: inline-block;
}
.navbar .nav-item.open > a {
	background: none !important;
}
.navbar .dropdown-menu {
	border-radius: 1px;
	border-color: #e5e5e5;
	box-shadow: 0 2px 8px rgba(0,0,0,.05);
}
.navbar .dropdown-menu a, .navbar .dropdown-menu a:active {
	color: #777;
	padding: 8px 20px;
	font-size: 13px;
  	background: #fff;
}
.navbar .dropdown-menu a:hover, .navbar .dropdown-menu a:focus {
	color: #333;
  	background: #f8f9fa;
}
@media (min-width: 992px){
	.form-inline .input-group .form-control {
		width: 225px;			
	}
}
@media (max-width: 992px){
	.form-inline {
		display: block;
	}
}
</style>
</head> 
<body>
<nav class="navbar navbar-expand-lg navbar-light">
	<a href="#" class="navbar-brand">Brand<b>Name</b></a>  		
	<button type="button" class="navbar-toggler" data-toggle="collapse" data-target="#navbarCollapse">
		<span class="navbar-toggler-icon"></span>
	</button>
	
	<div id="navbarCollapse" class="collapse navbar-collapse justify-content-start">
		<div class="navbar-nav">
			<a href="#" class="nav-item nav-link">Home</a>
			<a href="#" class="nav-item nav-link">About</a>			
			<div class="nav-item dropdown">
				<a href="#" data-toggle="dropdown" class="nav-item nav-link dropdown-toggle">Services</a>
				<div class="dropdown-menu">					
					<a href="#" class="dropdown-item">Web Design</a>
					<a href="#" class="dropdown-item">Web Development</a>
					<a href="#" class="dropdown-item">Graphic Design</a>
					<a href="#" class="dropdown-item">Digital Marketing</a>
                </div>
            </div>
			<a href="#" class="nav-item nav-link active">Portfolio</a>
			<a href="#" class="nav-item nav-link">Blog</a>
			<a href="#" class="nav-item nav-link">Contact</a>
        </div>
		<form class="navbar-form form-inline ml-auto">
			<div class="input-group search-box">
				<input type="text" class="form-control">
				<div class="input-group-append">
					<button type="button" class="btn btn-danger"><span>Search</span></button>
				</div>
			</div>
		</form>		
	</div>
</nav>
</body>
</html>