header{
    background-color: gray;
}
nav{
    height: 10%;
    background-color: #494949;
}
a{
    color: white;
}
ul{
    list-style-type: none;
}
li{
    display: inline;
}
article{
    display: inline-block;
    vertical-align: top
    border: 2px solid black;
    border-radius: 5px;
    width: 31%;
    height: 300px;
    margin-left: 20px;
    background-color: #F7E0AE;
  }
footer{
    margin-top: 20px;
    height: 50px;
    background-color: #494949;
    text-align: center;
    color: white;
}
h1{
    text-align: left;
}
img{
    display: block;
    margin: auto;
}