How to fix overlapping footer content when resizing

I have a problem with the template. It looks great on the big screen, like this:

But when I resize my browser, the content won't pop up the footer. Here's a picture:

Here is my code which is too long, so forgive me. index.php

<!-- Navigation -->
<nav class="navbar navbar-default navbar-fixed-top">
    <div class="container">
        <!-- Brand and toggle get grouped for better mobile display -->
        <div class="navbar-header page-scroll">
            <!-- simple code -->
        </div>

        <!-- Collect the nav links, forms, and other content for toggling -->
        <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
            <!-- simple code -->
        </div>
        <!-- /.navbar-collapse -->
    </div>
    <!-- /.container-fluid -->
</nav>

<!-- Begin page content -->
<header>
    <div class="container">
        <div class="row">
            <div class="col-lg-12">
                <img class="img-responsive" src="<?php echo base_url(); ?>assets/img/simple_img.png" alt="" style="height: 200px;">
                <div class="intro-text">
                    <!-- simple intro -->
                </div>
            </div>
        </div>
    </div>
</header>

<footer class="text-center">
    <div class="footer-above">
        <div class="container">
            <div class="row">
                <div class="footer-col col-md-4">
                    <h3>Location</h3>
                    <p>3481 Melrose Place<br>Beverly Hills, CA 90210</p>
                </div>
                <div class="footer-col col-md-4">
                    <h3>Around the Web</h3>
                    <ul class="list-inline">
                        <!-- some social networks -->
                    </ul>
                </div>
                <div class="footer-col col-md-4">
                    <h3>About Freelancer</h3>
                    <p>Freelance is a free to use, open source Bootstrap theme created by <a href="http://startbootstrap.com">Start Bootstrap</a>.</p>
                </div>
            </div>
        </div>
    </div>
    <div class="footer-below">
        <div class="container">
            <div class="row">
                <div class="col-lg-12">
                    Copyright &copy; Author <?php echo date("Y"); ?>
                </div>
            </div>
        </div>
    </div>
</footer>

      

        
        
        
      

    

Here is my Css, which is too long, so forgive me (I removed some irrelevant code).

            /* Sticky footer styles
        -------------------------------------------------- */
        html {
          position: relative;
          min-height: 100%;
        }
        body {
          /* Margin bottom by footer height */
          margin-bottom: 60px;
        }
        footer {
          position: absolute;
          bottom: 0;
          width: 100%;
          /* Set the fixed height of the footer here */
          height: 340px;
          background-color: #f5f5f5;
        }


        /* Custom page CSS
        -------------------------------------------------- */
        /* Not required for template or sticky footer method. */

        body > .container {
          padding: 60px 15px 0;
        }
        .container .text-muted {
          margin: 20px 0;
        }

        footer > .container {
          padding-right: 15px;
          padding-left: 15px;
        }

        code {
          font-size: 80%;
        }

        /*!
         * Start Bootstrap - Freelancer Bootstrap Theme (http://startbootstrap.com)
         * Code licensed under the Apache License v2.0.
         * For details, see http://www.apache.org/licenses/LICENSE-2.0.
         */

        body {
            overflow-x: hidden;
        }

        header {
            text-align: center;
            color: #fff;
            background: #18bc9c;
        }

        header .container {
            padding-top: 100px;
            padding-bottom: 50px;
        }

        @media(min-width:768px) {
            header .container {
                padding-top: 200px;
                padding-bottom: 69px;
            }

            header .intro-text .name {
                font-size: 4.75em;
            }

            header .intro-text .skills {
                font-size: 1.75em;
            }
        }

        @media(min-width:768px) {
            .navbar-fixed-top {
                padding: 25px 0;
                -webkit-transition: padding .3s;
                -moz-transition: padding .3s;
                transition: padding .3s;
            }

            .navbar-fixed-top .navbar-brand {
                font-size: 2em;
                -webkit-transition: all .3s;
                -moz-transition: all .3s;
                transition: all .3s;
            }

            .navbar-fixed-top.navbar-shrink {
                padding: 10px 0;
            }

            .navbar-fixed-top.navbar-shrink .navbar-brand {
                font-size: 1.5em;
            }
        }

        .navbar {
            text-transform: uppercase;
            font-family: Montserrat,"Helvetica Neue",Helvetica,Arial,sans-serif;
            font-weight: 700;
        }

        .navbar a:focus {
            outline: 0;
        }

        .navbar .navbar-nav {
            letter-spacing: 1px;
        }

        .navbar .navbar-nav li a:focus {
            outline: 0;
        }

        .navbar-default,
        .navbar-inverse {
            border: 0;
            background-color:#233140;
        }

        footer {
            color: #fff;
        }

        footer h3 {
            margin-bottom: 30px;
        }

        footer .footer-above {
            padding-top: 50px;
            background-color: #2c3e50;
        }

        footer .footer-col {
            margin-bottom: 50px;
        }

        footer .footer-below {
            padding: 25px 0;
            background-color: #233140;
        }

      

        
        
        
      

    

How can I solve this so the page content will nudge the footer ... at any browser size. Any help is appreciated.