/*default is designed for min-320width*/

a {
  text-decoration: none;
}

nav {
  background-color: #f1f1f1;
  overflow: hidden;
  box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
}

nav .logo {
  display: block;
  float: left;
  height: 4em;
}

h1, h3 {
  font-family: "Comic Sans MS", cursive, sans-serif;
}

h1, h3, p {
  margin: 8px;
  /*i used px here because it's the default margin and padding*/
  padding: 8px;
}

@media screen and (min-width:425px) {
  nav .logo {
    float: none;
  }
}

@media screen and (min-width:645px) {
  nav .logo {
    float: left;
    margin-right: 1em;
  }
}

nav .dropdown-arrow {
  vertical-align: middle;
  display: inline;
}

nav .up-number {
  margin: 0;
  margin-right: 0.2em;
  padding: 0;
  color: gray;
  line-height: 4rem;
  float: right;
}

@media screen and (min-width:425px) {
  nav .up-number {
    margin-right: 0.6em;
    line-height: 2rem;
    float: right;
  }
}

@media screen and (min-width:645px) {
  nav .up-number {
    margin-right: 1em;
    line-height: 4rem;
  }
}

nav ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  float: left;
}

nav ul li {
  border-right: 1px solid #bbb;
  line-height: 2em;
}

@media screen and (min-width:645px) {
  nav ul li {
    line-height: 4em;
  }
}

nav>ul>li {
  float: left;
}

nav ul li:last-child {
  border-right: none
}

nav ul li a {
  display: block;
  padding: 0 1em;
  color: gray;
}

nav ul li:hover > a {
  background-color: silver;
}

nav li.active {
  background-color: silver;
}

/*********DROPDOWN*******/

nav .dropdown {
  overflow: hidden;
  display: inline-block;
  vertical-align: middle;
}

nav .dropdown-content {
  display: none;
  position: absolute;
  box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
  border: 1px solid #bbb;
}

nav .dropdown-content li {
  border-right: none;
  border-bottom: 1px solid #bbb;
  position: relative;
  z-index: 1;
}

nav .dropdown-content a {
  float: none;
  text-decoration: none;
  text-align: left;
  display: block;
  background-color: #b3b3b3;
}

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

/*********END OF DROPDOWN*******/

html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background-color: #e6e6e6;
}

main #welcome p{
  margin-top: 0;
  margin-bottom: 0;
  padding-top: 0;
}

main #welcome p:last-child{
  margin-bottom: 2em;
}
main .index-container {
  display: block;
  margin: 0 auto;
  text-align: center;
}

main .index-container img{
  width: 32%;
  display: inline-block;
  height: auto;
}

@media screen and (min-width:635px) {
  main .index-container img {
    width: 12.19125em;
  }
}

@media screen and (min-width:666px) {
  main .index-container img {
    margin-right: 1%;
    margin-left: 1%;
  }
}

@media screen and (min-width:928px) {
  main .index-container img {
    margin-right: 8%;
    margin-left: 2%;
  }
}
main .index-container .welcome-img{
  border-radius: 8px;
}
main .index-container .obama-img {
  -webkit-animation: rotation 2s infinite linear;
}

@-webkit-keyframes rotation {
  from {
    -webkit-transform: rotate(0deg);
  }
  to {
    -webkit-transform: rotate(359deg);
  }
}

main .index-container figcaption {
  font-family: "Lucida Console", Monaco, monospace;
  margin-bottom: 5em;
}

/******* LITERATURE-REVIE ********/

main .lit-review {
  display: block;
  margin-bottom: 5em;
}

@media screen and (min-width:645px) {
  main .lit-review {
    margin: auto;
    margin-bottom: 6em;
  }
}

main .lit-review header h1 {
  text-align: center;
}

main .lit-review p {
  font-family: Arial, Helvetica, sans-serif;
  text-align: justify;
}

main .lit-review #references {
  overflow-wrap: break-word;
  text-align: left;
}

main .lit-review-index {
  display: block;
  background-color: #b3b3b3;
  text-align: center;
  margin: 1em;
  padding-bottom: 0.2em;
  border-radius: 8px;
}

@media screen and (min-width:645px) {
  main .lit-review-index {
    float: left;
    width: 25%;
  }
}

main .lit-review-index ul {
  margin: 0;
  padding: 0;
  list-style-type: none;
}

main .lit-review-index li {
  display: block;
  border-bottom: 1px solid #c0c0c0;
  font-family: Arial, Helvetica, sans-serif;
  padding: 2px;
}

main .lit-review-index li a {
  color: #000000;
}

main .lit-review-index li:hover {
  background-color: silver;
}

main .lit-review-index li:first-child {
  border-top: 1px solid #c0c0c0;
}

main .lit-review-index li:last-child {
  border-bottom: none;
}

/******* END OF LITERATURE REVIE ********/

/***** DISC LOG ******/
main .disclog {
  display: block;
  margin-bottom: 5em;
}

@media screen and (min-width:645px) {
  main .disclog {
    margin: auto;
    margin-bottom: 6em;
  }
}

main .disclog header h1 {
  text-align: center;
}

main .disclog p {
  font-family: Arial, Helvetica, sans-serif;
  text-align: justify;
}

main .disclog-index {
  display: block;
  background-color: #b3b3b3;
  text-align: center;
  margin: 1em;
  padding-bottom: 0.2em;
  border-radius: 8px;
}

@media screen and (min-width:645px) {
  main .disclog-index {
    float: left;
    width: 25%;
  }
}

main .disclog-index ul {
  margin: 0;
  padding: 0;
  list-style-type: none;
}

main .disclog-index li {
  display: block;
  border-bottom: 1px solid #c0c0c0;
  font-family: Arial, Helvetica, sans-serif;
  padding: 2px;
}

main .disclog-index li a {
  color: #000000;
}

main .disclog-index li:hover {
  background-color: silver;
}

main .disclog-index li:first-child {
  border-top: 1px solid #c0c0c0;
}

main .disclog-index li:last-child {
  border-bottom: none;
}

/******* ABOUT ME ********/

main #about-me {
  display: block;
}

main #about-me p {
  font-family: Arial, Helvetica, sans-serif;
  text-align: center;
}

#video {
  /* box-shadow: 0 -5px 6px rgba(0, 0, 0, 0.5); */
  box-shadow: 0 0 15px rgba(0, 0, 0, 0.5);
  display: block;
  margin: auto;
  height: auto;
  width: 60%;
}

footer {
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  background-color: #f1f1f1;
  box-shadow: 0 -2px 12px rgba(0, 0, 0, 0.5);
}

footer p {
  margin-top: 0.2em;
  margin-bottom: 0.2em;
  padding: 0;
  text-align: center;
}

footer figure {
  text-align: center;
  margin: 0;
}

footer img {
  margin-right: 4.5%;
  margin-left: 1%;
}