loginbox

login.css

body { 
  background: url(http://lorempixel.com/1920/1920/city/9/) no-repeat center center fixed; 
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

.panel-default {
opacity: 0.9;
margin-top:30px;
}
.form-group.last { margin-bottom:0px; }

login.html

<div class="container">
    <div class="row">
        <div class="col-md-4 col-md-offset-7">
            <div class="panel panel-default">
                <div class="panel-heading">
                    <span class="glyphicon glyphicon-lock"></span> Login</div>
                <div class="panel-body">
                    <form class="form-horizontal" role="form">
                    <div class="form-group">
                        <label for="inputEmail3" class="col-sm-3 control-label">
                            Email</label>
                        <div class="col-sm-9">
                            <input type="email" class="form-control" id="inputEmail3" placeholder="Email" required>
                        </div>
                    </div>
                    <div class="form-group">
                        <label for="inputPassword3" class="col-sm-3 control-label">
                            Password</label>
                        <div class="col-sm-9">
                            <input type="password" class="form-control" id="inputPassword3" placeholder="Password" required>
                        </div>
                    </div>
                    <div class="form-group">
                        <div class="col-sm-offset-3 col-sm-9">
                            <div class="checkbox">
                                <label>
                                    <input type="checkbox"/>
                                    Remember me
                                </label>
                            </div>
                        </div>
                    </div>
                    <div class="form-group last">
                        <div class="col-sm-offset-3 col-sm-9">
                            <button type="submit" class="btn btn-success btn-sm">
                                Sign in</button>
                                 <button type="reset" class="btn btn-default btn-sm">
                                Reset</button>
                        </div>
                    </div>
                    </form>
                </div>
                <div class="panel-footer">
                    Not Registred? <a href="http://www.jquery2dotnet.com">Register here</a></div>
            </div>
        </div>
    </div>
</div>