@charset "utf-8";
html{
    background-color:rgba(0,0,139,0.5);
    /*background-image: url(thunderbolt.png);*/
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-position: center center;
    background-size: 100% 100%;
}

body{
    background-color:rgb(1, 1, 155);
    color:rgb(255,255,255);
    font-family: Verdana, Geneva, sans-serif;
    width: 90%;
    margin-left: auto;
    margin-right: auto;
}
header{
    text-align:center;
    padding: 20px;
    text-decoration:none;
    color:white;
}

h1{
    text-shadow: gray 4px 6px 5px; 
}
h2{
    font-size: 1.3em;
    text-shadow: gray 4px 6px 5px;
}
table{
    width:100%;
    border: 18px solid black;
    border-collapse: collapse;
}
th, td{
    border: 1.5px solid black;
    height: 15px;
    padding: 5px;
}
thead, tfoot{
    background-color:blue;
}
tbody tr:nth-of-type(even){
     background-color:gray;
}
tbody tr:nth-of-type(odd){
     background-color:rgb(76, 76, 76);
}
/*
nav{
    background-color:grey; 
    padding: 15px;
    text-align:center;

}
nav a{
    padding-left: 10px;
    padding-right: 10px;
    text-decoration: none;
    color:white;

}
nav a:hover
{
    text-decoration:underline;
    color:red;
}
*/
nav ul{
    list-style: none;
    list-style-image: none;
    margin:0;
    padding:0;
}
nav li{
    float:left;
    width: 20%;
    display:block;
}
nav a{
    text-decoration: none;
    display:block;
    background-color:grey; 
    line-height: 2.8em;
    text-align: center; 
    color:white;

}
nav a:hover
{
  background-color:red;
}
main{
    padding:20px;
    margin-top: 35px;
}
 main > img{
    width: 25%;
    padding: 25px;
    display:block;
    margin-left:auto;
    margin-right:auto; 
    float: right;
}
    
body > footer{
    background-color:grey; 
    color:rgba(255,255,255,0.6);
    font: normal bold 0.9em/3em;
    text-align: center;
    margin-top:10px;
    padding:10px;
    clear: both;
}

ul{
    list-style-type: circle;
}

header img{
    width: 100%;
}
div.gallery{
    display:flex;
    flex-flow:wrap;
    

}
div.imgGallery{
    flex:23%;
    max-width:25%;
    padding: 0 4px;
}
div.imgGallery img{
    width: 100%;
}

@media only screen and (max-width: 1100px){
    div.imgGallery{
    flex:48%;
    max-width:50%;
    
}
}

@media only screen and (max-width: 768px){
body{
     width: 100%;
     margin: 0;
 }
 
main > img {
     width:90%;
     float:none;
 }
nav li{
     float:none;
     width: 100%;
     display:block;
 }
nav a{
    border-bottom: solid black 1px;
}
div.imgGallery{
    flex:100%;
    max-width:100%;
    
}
table, tbody, tr, td, th{
    display: block;
}
thead, tfoot{
    display: none;
}
tbody td{
    position: relative;
    padding-left: 40%;
    overflow: visible;
    height: auto;
}
td::before{
    content: attr(data-label);
    position: absolute;
    top: 0px;
    left: 0px;
    padding: 10px;
    width: 40%;
    white-space: nowrap;
}
    
}



@media only screen and (min-width: 769px){
  html{
    background-image: url(thunderbolt.png);

  }
  
}