Wordpress Cookies Managing. Is not all the code, but It's the first template.

JS Cookies Managing (Wordpress, jQuery & Bootstrap)

(function(){
    var //cookie
        , $btnCookie        = $('#btn-acceptCookies')
        , $divCookie        = $('div.cookiesAlert')
        , theCookieKey      = 'THE_SITE_NAME_cookie_policy'
        , theCookieVal      = 'accepted'
        , theCookieDays     = 15
        //cookie erasing
        , $btnDeleteCookies = $('#btn-deleteAllCookies')
        , cookieDeleteText  = 'Our cookies have been removed from your device successfully. '
            + '<a id="deleteAllCookiesConfirm" class="btn btn-danger btn-cookies" href="#deleteAllCookiesConfirm">OK</a>'
        //cookie functions
        ,setCookie = function(key, value, days) {
            var   expires = ''
                , date = new Date()
                ;
            if (days) {
                date.setTime( date.getTime()+(days*24*60*60*1000) );
                expires = "; expires=" + date.toGMTString();
            }
            document.cookie = key + "=" + value + expires + "; path=/";
        }
        , eraseCookie = function(key) {
            setCookie(key, "", -1);
        }
        , eraseAllCookies = function() {
            var   cookies = document.cookie.split(';')
                , cookiesLength = cookies.length
                , i = 0
                ;
            for(;i < cookiesLength; i++) {
                eraseCookie(cookies[i]);
            }
        }
        , getCookie = function(key) {
            var keyEQ = key + "="
                , cookies = document.cookie.split(';')
                , cookie
                , i = 0
                ;
            for(;i < cookies.length; i++) {
                cookie = cookies[i];
                while (cookie.charAt(0) == ' ')
                    cookie = cookie.substring(1, cookie.length);
      
                if (cookie.indexOf(keyEQ) == 0)
                    return cookie.substring(keyEQ.length, cookie.length);
            }
            return null;
        }
        ;
        
    //cookies
    if($btnCookie.length) {
        $btnCookie.on('click', function(e) {
            e.preventDefault();
            setCookie(theCookieKey, theCookieVal, theCookieDays);
            $divCookie.addClass(theCookieVal);
        });
    }
    
    if($btnDeleteCookies.length) {
        $btnDeleteCookies
            .popover({
                  'content' : cookieDeleteText
                , 'html'    : true
            })
            .on('click', function(e) {
                e.preventDefault();
                eraseAllCookies();
            });

        $btnDeleteCookies.on('shown.bs.popover', function () {
            $('#deleteAllCookiesConfirm').on('click', function(e) {
                e.preventDefault();
                $btnDeleteCookies.popover('hide');
            });
        })
    }

})(jQuery);

LESS Cookies Managing

//COOKIE MESSAGE
.cookiesAlert {
  background: @darkgray;
  color: white;
  font-size: 1.3rem;
  overflow: hidden;
  text-align: center;

  &.accepted {
    .container {
      margin-top: -30%;
    }
  }

  .container {
    .transition(all ease 3s);
    position: relative;
    overflow: hidden;
    padding: 1.5rem;

    a {
      color: @white;
      text-decoration: underline;
      white-space: nowrap;

      &.btn-cookie {
        margin: .7rem;
        padding: .3rem .8rem;
        background: white;
        color: @darkgray;
        text-decoration: none;
        border-radius: 5px;
        border-bottom: 2px solid darken(@white, 25%);
      }
    }

    p {
      margin: 0;
    }
  }
}

//Button Delet Cookie
.btn-cookies {
  padding: 0 .5rem;
  font-size: 1.2rem;
  position: relative;
  display: inline-block;
  top: -2px;
  margin-left: .2rem;
}

.popover {
  font-size: 1.3rem;
  border-color: @brand-danger;
  color: @brand-danger;

  &.right > .arrow {
    border-right-color: @brand-danger;
  }
}

PHP Cookies Managing (Wordpress)

<?php
/**
 * Hook this on the top of the body
 */
function cookie_message() {

    if( isset($_COOKIE['THE_SITE_NAME_cookie_policy']) ){
        $theCookieDays = 15; //expire 15 days
        setcookie('THE_SITE_NAME_cookie_policy', 'accepted', time()+($theCookieDays*3600*24), '/');
        return;
    }

    $cookieURL = 'http://THE_SITE_NAME_URL/COOKIES_PAGE';
    ?>
    <div class="cookiesAlert">
        <div class="container">
            <div class="col-xs-12 col-sm-12">
                <p>In <?php bloginfo('name') ?> We use proprietary and third party cookies. We consider that if you continue to browse accepts use. <a href="<?php echo $cookieURL ?>">Learn more</a><a class="btn-acceptCookies" href="#aceptar-cookies">Ok</a></p>
            </div>
        </div>
    </div>
    <?php
}