jak zrobić nav taki jak na tej stronie

Dzień dobry mam pytanie odnośnie nava takiego jak na stronie. Można rozwinąć menu pojechać w dół strony i on nie jedzie w dół a jak wrócimy dalej jest rozwinięty. Mam taki kod:

<!DOCTYPE html>
<html lang="pl" dir="ltr">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="css/style.css">
    <link rel="stylesheet" href="css/fontello.css">
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.min.js" charset="utf-8"></script>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" integrity="sha384-wvfXpqpZZVQGK6TAh5PVlGOfQNHSoD2xbE+QkPxCAFlNEevoEH3Sl0sibVcOQVnN" crossorigin="anonymous">
  	<link href="https://fonts.googleapis.com/css?family=Open+Sans:400,700&amp;subset=latin-ext" rel="stylesheet">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.12.1/css/all.min.css">
    <title>Moja strona</title>
</head>
<body>
    <h2 class="logotype">Tytuł strony</h2>
<header class="nav">
    <div class="inner-width">
        <a href="strona-główna" class="logo"><img src="img/logo.png" alt="logo"></a>
        <i class="menu-toggle-btn fas fa-bars"></i>
        <nav class="navigation-menu">
          <a href="strona-główna"><i class="fas fa-home home"></i>Strona główna</a>
          <a href="#"><i class="fas fa-bone suki"></i>#i</a>
          <a href="#"><i class="fas fa-dog psy"></i>#</a>
          <a href="#"><i class="fas fa-paw mioty"></i>#</a>
          <a href="#"><i class="fas fa-book tm"></i>#</a>
          <a href="#"><i class="fas fa-envelope con"></i>Kontakt</a>
  <a href="home"><img height= "29px" src="img/wb.png" alt="Język angielski"></a>
        </nav>
    </div>
</header>
    <div id="container">

*{
  margin: 0;
  padding: 0;
  text-decoration: none;
  font-family: "Open Sans",sans-serif;
  box-sizing: border-box;
}
::-webkit-scrollbar
{
 width: 0;
}
header.nav{
  height: 90px;
  background: #0066CC;
}

.inner-width{
  max-width: 1000px;
  padding: 0 10px;
  margin: 0 auto;
}

.logo{
  float: left;
  padding: 10px 0;
}

.logo img{
  height: 75px;
}

.navigation-menu{
  float: right;
  display: flex;
  align-items: center;
  min-height: 90px;
}

.navigation-menu a{
  margin-left: 5px;
  color: #ddd;
  text-transform: uppercase;
  font-size: 14px;
  padding: 12px 10px;
  border-radius: 12px;
  transition: .3s linear;
}

.navigation-menu a:hover{
  background: #fff;
  color: #2f3640;
  transform: scale(1.05);
}

.navigation-menu i{
  margin-right: 8px;
  font-size: 16px;
}

.home{
  color: #ff6b6b;
}

.suki{
  color: #0abde3;
}

.psy{
  color: #feca57;
}

.mioty{
  color: #5f27cd;
}

.tm{
  color: #1dd1a1;
}
.con{
  color: #CC6600;
}
.slidershow{
  width: 700px;
  height: 400px;
  overflow: hidden;
}
.middle{
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
}
.navigation{
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
}
.bar{
  width: 50px;
  height: 10px;
  border: 2px solid #fff;
  margin: 6px;
  cursor: pointer;
  transition: 0.4s;
}
.bar:hover{
  background: #fff;
}
.sliderek
{
  margin-top: 50px;
  padding-bottom: 500px;
  position: sticky;
}
.menu-toggle-btn{
  float: right;
  height: 90px;
  line-height: 90px !important;
  color: #fff;
  font-size: 26px;
  display: none !important;
  cursor: pointer;
}


@media screen and (max-width:1010px) {
  .menu-toggle-btn{
    display: block !important;
  }

  .navigation-menu{
    position: fixed;
    width: 100%;
    max-width: 400px;
    background: #172b4d;
    top: 94px;
    right: 0;
    display: none;
    padding: 20px 40px;
    box-sizing: border-box;
  }

  .navigation-menu::before{
    content: "";
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-bottom: 10px solid #172b4d;
    position: absolute;
    top: -10px;
    right: 10px;
  }

  .navigation-menu a{
    display: block;
    margin: 10px 0;
  }

  .navigation-menu.active{
    display: block;
    margin-top: 90px;
    z-index: 1;
  }
}
body
{
  background-color: #3399CC;
}
#container
{
  max-width: 1000px;
  margin-left: auto;
  margin-right: auto;
  text-align: center;
  color: #fff;
}
h2.logotype{
  color: #ddd;
  text-transform: uppercase;
  text-align: center;
  letter-spacing: 5px;
  font-size: 40px;
  padding: 20px 0;
  white-space: nowrap;
}
.miotzapowiedz{
    color: #fff;
    font-size: 44px;
    font-family: 'Open Sans', sans-serif;
    font-size: 40px;
    font-weight: 400;
    margin-bottom: 40px;
  }
h1{
    font-size: 44px;
    font-weight: 400;
    color: #CCCC33;
    margin: 40px 0;
}
p {
    color: yellow;
    font-size: 20px;
}
.info {
    width: 100%;
    background-color: #0066CC;
    color: white;
    text-align: center;
    padding: 40px;
    margin: 50px 0;
}
a.bluebutton
{
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 200px;
  height: 60px;
  text-align: center;
  line-height: 60px;
  color: #fff;
  font-size: 24px;
  text-transform: uppercase;
  text-decoration: none;
  font-family: sans-serif;
  box-sizing: border-box;
  background: linear-gradient(90deg, #03d6f4, #f441a5, #ffeb3b, #03a9f4);
  background-size: 400%;
  border-radius: 30px;
  padding: 15px 25px;
}
a.bluebutton:hover
{
  animation: animate 8s linear infinite;
}
@keyframes animate {
  0%
  {
    background-position: 0%;
  }
  100%
  {
    background-position: 400%;
  }

}
a.bluebutton:before
{
  width: 200px;
  height: 60px;
  content: '';
  position: relative;
  top: -5px;
  left: -5px;
  right: -5px;
  bottom: -5px;
  z-index: -1;
  background: linear-gradient(90deg, #03a9f4, #f441a5, #ffeb3b, #03a9f4);
  background-size: 400%;
  border-radius: 30px;
  filter: blur(20px);
}
.fb
{
  width: 100px;
  text-align: center;
  margin-left: auto;
  margin-right: auto;
  margin-top: 30px;
}
ul
{
  position: relative;
  display: flex;
}
ul li
{
  position: relative;
  list-style: none;
}
ul li a
{
  position: relative;
  width: 80px;
  height: 80px;
  display: flex;
  justify-content: center;
  align-items: center;
  background: #fff;
  margin: 0 10px;
  text-decoration: none;
  font-size: 30px;
  border-radius: 50%;
  color: #e2e2e2;
  box-shadow: inset -1px -1px 2px rgba(0,0,0,0.2),
                    2px 2px 5px rgba(0,0,0,0.2);
  transition: 0.5s;
}
ul li a:hover
{
  color: #999;
  transform: translateY(-20px);
  box-shadow: inset -1px -1px 2px rgba(0,0,0,0.2),
                    2px 24px 10px rgba(0,0,0,0.1);
}
ul li a:before
{
  content: '';
  position: absolute;
  top: 10px;
  left: 10px;
  right: 10px;
  bottom: 10px;
  border-radius: 50%;
  border: 2px solid rgba(0,0,0,0.1);
}
ul li a .icon-facebook
{
  color: #fff;
  position: relative;
  z-index: 1;
}
ul li:nth-child(1) a:before
{
  background: #1077f2;
}

.stopka{
  color: #fff;
  background-color: #0066CC;
  text-align: center;
  width: 100%;
  padding: 15px;
  margin-top: 20px;
}

#container a
{
	opacity: 0.9;
}
#container a:hover
{
	opacity: 1;
}
.molly{
  margin-top: 50px;
  position: relative;
}
.mio{
  color: #fff;
}
.scrollup
{
  width: 64px;
  height: 64px;
  text-decoration: none;
  background: url("img/up.png") no-repeat 0px 0px;
  position: fixed;
  right: 50px;
  bottom: 50px;
  display: none;
	border-radius: 5px;
}
.rodowod{
  width: 90%;
}
h2.rasa
{
  color: #333300;
}
.responsive
{
  max-width:100%;
}
#slider {
	overflow: hidden;
  margin-top: 40px;
}
#slider figure {
	position: relative;
	width: 500%;
	margin: 0;
	left: 0;
	animation: 20s slider infinite;
}
#slider figure img {
	width: 20%;
	float: left;
}

@keyframes slider {
	0% {
		left: 0;
	}
	20% {
		left: 0;
	}
	25% {
		left: -100%;
	}
	45% {
		left: -100%;
	}
	50% {
		left: -200%;
	}
	70% {
		left: -200%;
	}
	75% {
		left: -300%;
	}
	95% {
		left: -300%;
	}
	100% {
		left: -400%;
	}
}
@media screen and (min-width: 320px) {
  h2.logotype {
    font-size: calc(16px + 6 * ((100vw - 320px) / 680));
  }
    .navigation-menu{
      top: 62px;
  }
}
@media screen and (min-width: 1000px) {
  h2.logotype {
    font-size: 40px;
  }
}
.jezyka
{
  height: 29px;
  padding: 0;
  margin: auto;
}


#scrollPath
{
  position: fixed;
  top: 0;
  right: 0;
  width: 15px;
  height: 100%;
  background: rgba(255, 225, 225, 0.05);
}
#progressbar
{
  position: fixed;
  top: 0;
  right: 0;
  width: 15px;
  background: linear-gradient(to top, #008aff, #00ffe7);
  animation: animate 5s linear infinite;
}
@keyframes animate {
  0%,100%
  {
    filter: hue-rotate(0deg);
  }
  50%
  {
    filter: hue-rotate(360deg);
  }

}
#progressbar:before{
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(to top, #008aff, #00ffe7);
  filter: blur(10px);
}
#progressbar:after{
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(to top, #008aff, #00ffe7);
  filter: blur(30px);
}

i chciałbym naprawić menu active tak żeby nie odczepiało się od menu i jechało wraz z zjeżdżaniem na dół strony

tak jak jest na tym forum