Navbar

Example 1

<!-- Navbar -->
<nav class="navbar navbar-expand-md navbar-light bg-light">
    <a class="navbar-brand" href="#">Navbar</a>
    <button class="navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#mobile-menu-1" aria-controls="mobile-menu-1" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    </button>

    <div class="navbar-collapse collapse" id="mobile-menu-1" style="">
        <ul class="navbar-nav mr-auto">
            <li class="nav-item active">
                <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Link</a>
            </li>
            <li class="nav-item dropdown">
                <a class="nav-link dropdown-toggle" href="#" id="navbar-dropdown-1" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    Dropdown
                </a>
                <div class="dropdown-menu" aria-labelledby="navbar-dropdown-1">
                    <a class="dropdown-item" href="#">Action</a>
                    <a class="dropdown-item" href="#">Another action</a>
                    <div class="dropdown-divider"></div>
                    <a class="dropdown-item" href="#">Something else here</a>
                </div>
            </li>
            <li class="nav-item">
                <a class="nav-link disabled" href="#">Disabled</a>
            </li>
        </ul>
        <form class="form-inline my-2 my-lg-0">
            <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
            <button class="btn btn-outline-dark my-2 my-sm-0" type="submit">Search
            </button>
        </form>
    </div>
</nav>
<!-- /navbar -->

Example 2

<!-- Navbar -->
<nav class="navbar navbar-expand-md navbar-dark bg-dark">
    <a class="navbar-brand" href="#">Navbar</a>
    <button class="navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#mobile-menu-1" aria-controls="mobile-menu-1" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    </button>

    <div class="navbar-collapse collapse" id="mobile-menu-1" style="">
        <ul class="navbar-nav mr-auto">
            <li class="nav-item active">
                <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Link</a>
            </li>
            <li class="nav-item dropdown">
                <a class="nav-link dropdown-toggle" href="#" id="navbar-dropdown-1" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    Dropdown
                </a>
                <div class="dropdown-menu" aria-labelledby="navbar-dropdown-1">
                    <a class="dropdown-item" href="#">Action</a>
                    <a class="dropdown-item" href="#">Another action</a>
                    <div class="dropdown-divider"></div>
                    <a class="dropdown-item" href="#">Something else here</a>
                </div>
            </li>
            <li class="nav-item">
                <a class="nav-link disabled" href="#">Disabled</a>
            </li>
        </ul>
        <form class="form-inline my-2 my-lg-0">
            <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
            <button class="btn btn-outline-dark my-2 my-sm-0" type="submit">Search
            </button>
        </form>
    </div>
</nav>
<!-- /navbar -->

Example 3

<!-- Navbar -->
<nav class="navbar navbar-expand-md navbar-dark bg-primary">
    <a class="navbar-brand" href="#">Navbar</a>
    <button class="navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#mobile-menu-1" aria-controls="mobile-menu-1" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    </button>

    <div class="navbar-collapse collapse" id="mobile-menu-1" style="">
        <ul class="navbar-nav mr-auto">
            <li class="nav-item active">
                <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Link</a>
            </li>
            <li class="nav-item dropdown">
                <a class="nav-link dropdown-toggle" href="#" id="navbar-dropdown-1" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    Dropdown
                </a>
                <div class="dropdown-menu" aria-labelledby="navbar-dropdown-1">
                    <a class="dropdown-item" href="#">Action</a>
                    <a class="dropdown-item" href="#">Another action</a>
                    <div class="dropdown-divider"></div>
                    <a class="dropdown-item" href="#">Something else here</a>
                </div>
            </li>
            <li class="nav-item">
                <a class="nav-link disabled" href="#">Disabled</a>
            </li>
        </ul>
        <form class="form-inline my-2 my-lg-0">
            <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
            <button class="btn btn-outline-dark my-2 my-sm-0" type="submit">Search
            </button>
        </form>
    </div>
</nav>
<!-- /navbar -->