Header.css

body {
  background-image: url("https://images.everydayhealth.com/images/everything-you-need-know-about-fitness-1440x810.jpg");
  background-size: cover;
  margin: 0;
  padding: 0;
}

#header {
  width: 100%;
  height: 73px;
  text-align: center;
  background-color: rgb(192, 192, 192);
  font-family: "Montserrat", sans-serif;
  font-weight: bold;
  font-size: 50px;
  padding: 20px 0 0 0;
}

#logOutBtn {
  float: right;
  background-color: rgb(99, 98, 98);
  width: 100px;
  border-style: solid;
  border-width: medium;
  color: white;
  font-family: "Roboto", sans-serif;
  font-weight: bold;
  padding: 5px 0 5px 0;
  cursor: pointer;
}

#logOutBtn:hover {
  background-color: rgb(149, 148, 148);
}

#welcomeMsg {
  text-align: center;
  background-color: rgba(99, 98, 98, 0.8);
  width: 500px;
  margin: 60px auto;
  padding: 20px 0 20px 0;
  border-radius: 50px;
  border-style: solid;
  border-width: medium;
}

#welcomeMsg p {
  color: white;
  font-family: "Roboto", sans-serif;
  font-weight: bold;
  font-size: 20px;
}

.btnContainer {
  text-align: center;
  width: 700px;
  margin: 60px auto;
}

.mainBtn {
  color: white;
  background-color: rgba(99, 98, 98, 0.8);
  width: 250px;
  height: 100px;
  line-height: 100px;
  border-radius: 50px;
  border-style: solid;
  border-width: medium;
  font-family: "Roboto", sans-serif;
  font-weight: bold;
  font-size: 20px;
  margin: 10px;
  cursor: pointer;
}

.mainBtn:hover {
  background-color: rgb(149, 148, 148);
}

.myGreeting {
  color: black;
  font-size: 28px;
  font-family: "Brush Script MT", cursive;
  /*border: solid;
    border-color: rgba(99, 98, 98, 0.8);
    background-color: black;
    border-radius: 5px;
    */
}

.topnav {
  overflow: hidden;
  background-color: rgb(192, 192, 192);
  position: relative;
  left: 5px;
  width: 100%;
  text-align: left;
}

.topnav #myNavBar {
  display: none;
}

.topnav a {
  color: white;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 55px;
  display: block;
}

.topnav a.icon {
  background: rgba(255, 102, 0, 0.8);
  display: block;
  position: absolute;
  left: 0;
  top: 0;
  border-style: solid;
  border-width: thin;
}

.topnav a:hover {
  background-color: #ddd;
  color: black;
}

.active {
  background-color: rgb(99, 98, 98);
  color: white;
  border-style: solid;
  border-width: thin;
}