body {
  font-family: Georgia, serif;
  background-color: #000000;
}

div {
  border: 1px solid grey;
  padding: 0px;  
}

div.gallery {
  /* border: 1px solid #ccc; */
  border: none;
}

div.gallery:hover {
  /* border: 1px solid #777; */
}

div.gallery img {
  width: 100%;
  height: auto;
}

div.desc {
  padding: 10px;
  color: blue;
  text-align: center;
  border: 0;
}

* {
  box-sizing: border-box;
}

.responsive {
  padding: 0 6px;
  float: left;
  width: 24.99999%;
}

@media only screen and (max-width: 700px) {
  .responsive {
    width: 49.99999%;
    margin: 6px 0;
  }
}

@media only screen and (max-width: 500px) {
  .responsive {
    width: 100%;
  }
}

.clearfix:after {
  content: "";
  display: table;
  clear: both;
}

h1 {
  text-align: center;
  /* text-transform: uppercase; */
  letter-spacing: 10px;
  padding: 1px;
  color: grey;
}

h4 {
  text-indent: 20px;
  text-align: left;
  letter-spacing: 2px;
  padding: 5px;
  color: grey;
}

h5 {
  text-align: left;
  letter-spacing: 4px;
  color: grey;
}

p {
  text-indent: 6%;
  text-align: justify;
  letter-spacing: 4px;
  color: white;
}

p.ex1 {
  margin-left: 3px;
}

a {
  text-decoration: none;
  color: yellow;
}

.header {
  background-color: #333333;
  padding: 10px;
  text-align: center;
}

.topnav {
  overflow: hidden;
  background-color: #121212;
}

.topnav a {
  float: left;
  display: block;
  color: yellow;
  text-align: center;
  font-weight: bold;
  padding: 10px 25px;
  text-decoration: none;
}

.topnav a:hover {
  background-color: #2f2f2f;
  color: white;
}

.tooltip {
  position: relative;
  display: inline-block;
  border: none;
  color: white;
}

.tooltip .tooltiptext {
  visibility: hidden;
  width: 100px;
  background-color: #333333;
  color: yellow;
  text-align: center;
  border-radius: 6px;
  padding: 5px 0;
  position: absolute;
  z-index: 1;
}

.tooltip:hover .tooltiptext {
  visibility: visible;
}

.container {
  position: relative;
  width: 90%;
}
.image {
  opacity: 1;
  display: block;
  width: 100%;
  height: auto;
  transition: .5s ease;
  backface-visibility: hidden;
}
.middle {
  transition: .5s ease;
  opacity: 0;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
  text-align: center;
}
.container:hover .image {
  opacity: 0.3;
}
.container:hover .middle {
  opacity: 1;
}
.text {
  background-color: #2f2f2f;
  color: yellow;
  font-size: 16px;
  padding: 16px 32px;
}

.footer {
  background-color: #333333;
  padding: 3px;
  text-indent: 15px;
  color: yellow;
}