body {
    font-family: Arial, 'Courier New', Courier, monospace;
} 
.navbar { background-color: #000}


.thebackground {background-image: url(../images/Picture1a.png);}

.jumbotron {
    background-color: #eef;
}

.txtover {
    position: relative;
}
.textover figcaption {
    color: white;
    position: absolute;
    bottom: 0;
    left: 0;
}

<style>
.bd-placeholder-img {
  font-size: 1.125rem;
  text-anchor: middle;
  -webkit-user-select: none;
  -moz-user-select: none;
  user-select: none;
}

@media (min-width: 768px) {
  .bd-placeholder-img-lg {
    font-size: 3.5rem;
  }
}

.b-example-divider {
  height: 3rem;
  background-color: rgba(0, 0, 0, .1);
  border: solid rgba(0, 0, 0, .15);
  border-width: 1px 0;
  box-shadow: inset 0 .5em 1.5em rgba(0, 0, 0, .1), inset 0 .125em .5em rgba(0, 0, 0, .15);
}

.b-example-vr {
  flex-shrink: 0;
  width: 1.5rem;
  height: 100vh;
}

.bi {
  vertical-align: -.125em;
  fill: currentColor;
}

.nav-scroller {
  position: relative;
  z-index: 2;
  height: 2.75rem;
  overflow-y: hidden;
}

.nav-scroller .nav {
  display: flex;
  flex-wrap: nowrap;
  padding-bottom: 1rem;
  margin-top: -1px;
  overflow-x: auto;
  text-align: center;
  white-space: nowrap;
  -webkit-overflow-scrolling: touch;
}

.b-divider {
    height: 3rem;
    background-color: rgba(0, 0, 0, .1);
    border: solid rgba(0, 0, 0, .15);
    border-width: 1px 0;
    box-shadow: inset 0 .5em 1.5em rgba(0, 0, 0, .1), inset 0 .125em .5em rgba(0, 0, 0, .15);
  }

.vertical-centre {
    margin: 0px;
    position: absolute;
    top: 50%;
    -ms-transform: translateY(-50%);
    transform: translateY(-50%);
  }
.mytitle {
  font-size: 1.2rem;
  font-weight: bold;
  text-align: center;
  margin-bottom: 0;
}

.text-aligned {
  text-align: justify;
  text-justify: inter-word;
}

#myBtn {
  display: none; /* Hidden by default */
  position: fixed; /* Fixed/sticky position */
  bottom: 20px; /* Place the button at the bottom of the page */
  right: 30px; /* Place the button 30px from the right */
  z-index: 99; /* Make sure it does not overlap */
  border: none; /* Remove borders */
  outline: none; /* Remove outline */
  background-color: red; /* Set a background color */
  color: white; /* Text color */
  cursor: pointer; /* Add a mouse pointer on hover */
  padding: 15px; /* Some padding */
  border-radius: 10px; /* Rounded corners */
  font-size: 18px; /* Increase font size */
}

#myBtn:hover {
  background-color: #555; /* Add a dark-grey background on hover */
}