body, html {
  height: 100%;
  margin: 0;
  position: relative:
}

html {
  overflow-y: scroll; 
}

#bg {
  position: fixed;  
  width: 100%; 
  height: 100%;
  z-index: -1;
}
#bg img {
  position: absolute; 
  top: 0; 
  left: 0; 
  right: 0; 
  bottom: 0; 
  margin: auto; 
  min-width: 100%;
  min-height: 100%;
  z-index: -1;
  filter: saturate(0.4) opacity(0.5);
}

.fotogalerie {
  width: 600px;
  align-self: center;
}

.mapa {
  filter: saturate(0.9);
}

.firma {
  border-radius: 50px;
  padding: 30px;
}

.reference {
  border-radius: 10px;
  text-align:center;
  margin-left: auto;
  margin-right: auto;
  display:block;
  margin:0 auto;
}

.navbar {
  overflow: hidden;
  background-color: #333;
  background: rgba(0, 0, 0, 0.5);
  width: 1100px;
  align-self: center;
}

.navbar a {
  float: left;
  font-size: 16px;
  color: white;
  text-align: center;
  padding: 14px 30px;
  text-decoration: none;
  font-family: arial;
  font-weight: bold;
}

.dropdown {
  float: left;
  overflow: hidden;
}

.dropdown .dropbtn {
  font-size: 16px;  
  border: none;
  outline: none;
  color: white;
  padding: 14px 25px;
  background-color: inherit;
  font-family: arial;
  font-weight: bold;
  margin: 0;
}

.navbar a:hover, .dropdown:hover .dropbtn {
  background-color: #499feaff;
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #7abef9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
  opacity: 0.8;
}

.dropdown-content a {
  float: none;
  color: #2a2929;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
  text-align: left;
  font-family: arial;
  font-weight: bold;
}

.dropdown-content a:hover {
  background-color: #ddd;
  color: black;
}

.obsah {
  padding: 20px 40px;
  overflow: hidden;
  background-color: #333;
  background: rgba(0, 0, 0, 0.1);
  width: 1020px;
  align-self: center;
}

.obsah_sekce {
  color: white;
  text-align: right;
  font-family: Arial Black;
  font-weight: bold;
  font-size: 25px;
  text-decoration: overline;
}

.obsah_nadpis {
  color: #161412;
  text-align: left;
  font-family: arial;
  font-weight: bold;
  font-size: 25px;
}

.obsah_nadpis_mensi {
  color: #161412;
  text-align: left;
  font-family: arial;
  font-weight: bold;
  font-size: 20px;
}

.obsah_nadpis_nejmensi {
  color: #161412;
  text-align: left;
  font-family: arial;
  font-weight: bold;
  font-size: 18px;
}

.obsah_text {
  color: #161412;
  font-family: arial;
  font-weight: bold;
  font-size: 15px;
  text-align: justify;
}

.paticka {
  color: #161412;
  font-family: arial;
  font-weight: bold;
  font-size: 10px;
  text-align: center;
}

.obsah_nevyrazny {
  color: #161412;
  font-family: arial;
  font-size: 15px;
  text-align: justify;
}

.dropdown:hover .dropdown-content {
  display: block;