body {
  margin: 0;
  padding: 0;
  background: #006737;
}
header {
  background: #052C13;
}
header h1 {
  color: #fff;
  text-align: center;
}
#main {
  /* border: 20px solid #052C13; */
  height: 100vh;
  box-sizing: border-box;
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
	padding: 20px 0 0 0;
}

#main .content{
  width: 640px;
  margin: auto;
  position: relative;

}
#main ul{
  list-style: none;
  width: 100%;
  display: flex;
  justify-content: space-between;
}
#main .judg{
  text-align: center;
  z-index: 999;
}
#main .judg img{
  position: absolute;
  top: 44%;
  left: 50%;
  transform: translateY(-50%) translateX(-50%);
  -webkit- transform: translateY(-50%) translateX(-50%);
}
#echo{
  margin-top: 30px;
}

footer {
  background-color: #fff;
  text-align: center;
}
ul {
  padding: 0;
}
.btn, li.btn {
  width: 220px;
  margin: 0;
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.5;
  text-align: center;
  cursor: pointer;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
  -webkit-transition: all 0.3s;
  transition: all 0.3s;
  text-align: center;
  text-decoration: none;
  letter-spacing: 0.1em;
  color: #fff;
  border-radius: 0.5rem;
  list-style: none;
}
li.btn--y{
  background: #E67614;
  padding: 1rem 2rem;
}
li.btn--b{
  background: #0560F6;
  padding: 1rem 2rem;
}
li.btn--border-double {
  border: 8px double #000;
}
#echo {
  width: 360px;
  margin: 20px auto;
}
#echo img {
  width: 100%;
  border-radius: 20px;
}
@media screen and (max-width: 768px) {
  #main .content{
    width: 90%;
    margin: auto;
    position: relative;
  
  } 
  .btn, li.btn {
    width: 80%;
    margin: auto;
    padding: 1rem 0;
  }
  #echo {
    width: 85%;
    margin: auto;
    padding: 20px 0;
  }
}