html,body {
  height: 100%;
}

* {
  box-sizing: border-box;  
  -moz-box-sizing: border-box;
}

body {
  background-color: #222222;
  color: #ffffff;
  margin: 0;
  padding: 0;
  font-family: Tahoma, Verdana, sans-serif;
  font-size:21px;
  line-height:1.428571429;
  font-weight: normal;
}
h1,
h2,
h3,
h4,
h5,
h6,
.h1,
.h2,
.h3,
.h4,
.h5,
.h6 {
  font-weight: normal;
  line-height: 1.1;
  color: #ffffff;
  margin: 0;
  padding: 0;
}

h1 small,
h2 small,
h3 small,
h4 small,
h5 small,
h6 small,
.h1 small,
.h2 small,
.h3 small,
.h4 small,
.h5 small,
.h6 small {
  font-weight: normal;
  line-height: 1
}

h1,
.h1 {
  font-family: 'Courier New', Courier, monospace;
  font-size: 64px;
  font-weight:bold;
  margin: 0 0 1% 0;
  text-decoration: none;
}

h2,
.h2 {
  font-family: 'Courier New', Courier, monospace;
  font-size: 36px;
}

h3,
.h3 {
  font-size: 40px;
  font-weight:bold;
  margin-top: 70px;
  margin-bottom: 3%;
}

/* h4,
.h4 {
  font-size: 24px;
  line-height: 25px
}

h5,
.h5 {
  font-size: 20px;
  line-height: 24px
}

h6,
.h6 {
  font-size: 18px;
  line-height: 24px
} */


p{
  font-size: 21px;
}

.back-button {
    margin-left: 2%;
    margin-top:25px;
    float:left;
}

@media (max-width: 780px) {

  h1,
  .h1 {
    font-size: 42px;
  }

  h2,
  .h2 {
    font-size: 24px;
  }

  h3,
  .h3 {
    font-size: 32px;
  }

  p {
    font-size: 16px;
  }

  body {
    font-size: 16px;
  }
}


a {
   color: #6fc4b2;
}

a:hover,
a:focus {
  color: #ffffff;
  text-decoration: underline
}

.container {
  margin-left:  auto;
  margin-right:  auto;
  margin-top: 25px;
  max-width: 1170px;
  padding-right: 15px;
  padding-left: 15px;
}

.text-center {
  text-align: center
}

header {
  padding:2%;
  background-color: #6fc4b2;
}

h1 a,
h1 a:hover,
h1 a:focus,
h2 a,
h2 a:hover,
h2 a:focus {
  color: #ffffff;
  text-decoration: none;
}

.write-up {
    text-align: left;
    display: inline-block;
    vertical-align: top;
}

img {
    border: solid medium #6fc4b2;
    border-radius: 12px;
    margin: 10px;
    max-width: calc(100% - 20px);
}

img.horizontal {
    width: 512px;
    aspect-ratio: 16/9;
}

img.vertical {
    width: 288px;
    aspect-ratio: 9/16;
}