body{
        background-color: white;
        margin: 40px;
}

header{
        text-align: center;
        border-width: thick;
        border-color: green;
        border-style: dotted;
        padding-top: 15px;
}
h1{
    text-align: center;
    text-decoration: overline underline;
    font-size: 45px;
    color:green;
    font-family: sans-serif;
    margin-top: auto;
}

h2{
  text-align: center;
  color: green;
  text-decoration: underline;
}
h3{
  float: left;
  color: green;
  padding-left: : 20px;
  text-decoration-line: underline;
  font-family: sans-serif;
}

p{
    text-align: center;
    color: black;
    padding: 40px;
    font-size: 20px;
    font-family:monospace;
}

.background{
            background-color: lightgreen;
  }

#nav1 {
              display:flex;
              justify-content: center;
              list-style: none;
              border-bottom: 3px double green;
              margin-bottom: 50px;
              padding: 0;
              width: 100%;

  }
  nav ul li {
            margin-right: 50px;
            font-size: 17px;
            font-family:sans-serif;
  }

  .exercise_image{
      border-radius: 50px;
      justify-content: center;
      width: 100%;

    }