* {
  box-sizing: border-box;
}

body {
    margin: 0;
    background-color: #f1f1f1;
}

.header {
    height: 35rem;
    font-weight: bold;
    background-image: url('../images/klein_park2.jpg');
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
}

.header_text {
    padding: 30px;
    font-family: sans-serif;
    font-size: 45px;
    color: #ffffff;
    text-align: center;
}

.footer {
    text-align:center; 
    background-color:#f1f1f1;
    Color: gray;
    text-align: center;
} 

/* top navigation bar */
ul {
  list-style-type: none;
  margin: 0px;
  padding: 0px;
  overflow: hidden;
  background-color: #333;
}
li {
  float: left;
}
li a, .dropbtn {
  display: inline-block;
  color: white;
  text-align: center;
  padding: 14px 25px;
  text-decoration: none;
}
li a:hover, .dropdown:hover .dropbtn {
  background-color: red;
}
li.dropdown {
  display: inline-block;
}
.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
}
.dropdown-content a {
  color: black;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
  text-align: left;
}
.dropdown-content a:hover {background-color:#e5e5e5;}
.dropdown:hover .dropdown-content {
  display: block;
}

.button_container { 
  height: 40px;
  position: relative;
}

.button {
  background-color: #4CAF50; /* Green */
  border: none;
  color: white;
  padding: 12px 28px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
}

.center {
  margin: 0;
  position: absolute;
  top: 50%;
  left: 50%;
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

.column_main {
  padding: 20px;
  background-color: #ffffff;
}

.main_text {
    font-family: sans-serif, "Verdana";
    font-size: 20px;
    color: gray;
    text-align: center; 
    padding: 10px 70px 10px 70px;
}

/* Responsive layout...makes the columns stack on top of each other */
@media screen and (max-width: 600px) {
  .column_main {
    width: 100%;
  }
}