* {
  box-sizing: border-box;
}

html, body{
  margin: 0;
  padding: 0;
  line-height: 1.8;
}

header {
  color: #fff;
  padding: 3.2rem;
  background: url(/header.jpg);
  background-size: cover;
  background-position: center;
  backdrop-filter: brightness(0.7);
  font-weight: 700;
  font-size: 500%;
  text-align: center;
}

#nav {
  width: 100%;
  padding: .8rem;
  background: #eee;
}

#nav > a {
  text-decoration: none;
  font-size: 110%;
  padding: .6rem;
}

#nav > a:hover {
  background: #fff;
  border-radius: .5rem;
}


h1, h2 {
  border-bottom: 2px solid #14a;
  padding-top: .2rem;
  padding-bottom: .8rem;
}

#main {
  margin: auto;
  width: 75%;
  padding: .6rem;
}

.sec_expl {
  display: flex;
}

.sec_expl > * {
  padding: 1%;
}

.sec_expl > img {
  width: 35%;
  height: 100%;
}

.sec_expl > span.dsc {
  width: 60%;
}

@media screen and (max-width: 480px) {
  header {
    font-size: 300%;
  }
  #main {
    width: 90%;
  }
}