*{
padding:0px;
margin:0px;
box-sizing: border-box;

}



header{

  background-color: aliceblue;
}
nav{


  background-color: aqua;
}
main{
background-color: aquamarine;
min-height: 400px;

}
details{
  background-color: brown;
}
details>summary{
background-color: blueviolet;
list-style-type:none;
display: flex;
justify-content: space-between;

}
details>summary::after{

  content:"+";
  font-size: x-large;
  font-weight: 800;
}
details[open]>summary::after{

  content:"–";
  font-size: x-large;
  font-weight: 800;
}
nav>ul{
display:flex;
flex-direction: column;

nav>p{
display:none;

  
}

}
nav>details>ul>li>a{
display:block;
padding:20px;


}
nav>ul>li>a{
padding:20px;
background-color: azure;
text-align: center;
}

footer{
background-color: bisque;

}