body{
  background-color: #0a1223;
  font-family: Sans-Serif;
}
header{
  width: 100%;
  height: 100px;
}
a{
  text-decoration: none;
  color: #5d5d5d;
  padding: 20px;
}
nav{
  padding-top: 10px;
  display: flex;  
  justify-content: flex-end;
  
}
a:hover{
  color: #54597d;
}
a:active{
  color: #54597d; 
}
section{
  width: 90%;
  margin: 100px auto 0 auto;
}
h1{
  color: #ddd;
  font-size: 35px;
  font-size: 5vw;
  text-align: center;
  width: auto;
  height: auto;
}
article{
  width:80%;
  margin: 0 auto 50px auto;
  display: flex;
  align-items: center;
  align-content: center;
  justify-content: space-between;

}
p{
  text-indent: 20px;
  text-align: justify;
}
article div{
  width: 50%;
}
img{
  max-width: 50%;
  width: auto;
  height: auto;
  margin: 0 auto;
  }
.color-h2{
    background: linear-gradient(to right, #ddd, #5d5d5d);   
    -webkit-text-fill-color: transparent;
    -webkit-background-clip: text;
}
.color-p{
  color: #5d5d5d;
}
article:nth-child(even) {
  flex-direction: row-reverse;
}
article:nth-child(odd) {
  flex-direction: row;
}
.page-up{
    display: none;
  }
@media (max-width: 991px) {
  nav {
    justify-content: center;
  }
  article:nth-child(odd){
    display: flex;
    flex-direction: column;
  }
  article:nth-child(even){
    display: flex;
    flex-direction: column;
  }
  article div{
    width: 85%;
  }
  img{
    max-width:85%;
    width: auto;
    height: auto;
    margin: 0 auto;
  }
  .page-up{
    display: none;
  }
}
@media (max-width: 575px) {
  body{
    background: #fff;
  }
  nav{
    flex-direction: column;
    padding: 0;
  }
  a{
    padding: 5px;
    border-bottom: 1px solid #ddd;
  }
  a:active{
    font-weight: bold;
  }
  article{
    width: 100%;
    color: #ddd;
  }
  article div{
    width: 100%;
  }
  h1{
    font-size: 50px;
    color: #000;
    margin-top:70px; 
  }
  .color-h2{
    background: unset;   
    -webkit-text-fill-color: unset;
    -webkit-background-clip: unset;
    color: #484747;
  }
  .page-up{
    display: block;
    width: 50px;
    height: 50px;
    line-height: 50px;
    border-radius: 50%;
    background-color :#5ebcff;
    color: #fff;
    position: fixed;
    bottom: -80px;
    right: 20px;
    text-align: center;
    text-decoration: none;
    box-shadow: 10px 10px 20px lightgray;
  }
}