style.css

* {
    box-sizing: border-box;
    margin: 0;
    text-decoration: none;
    list-style-type: none;
    font-family: "Loto", sans-serif;
  }

  html {
    height: 100%;
  }

  body {
    background-image: url(img/run.jpeg);
    background-size:cover;
    background-attachment: fixed;
    background-repeat: no-repeat;
    height: 100%;
    display: flex;
    margin: 0px;
    overflow: hidden;
  }

  header {
    display: flex;
    justify-content: flex-start;
    padding: 10px 10px;
    text-align: center;
    align-items: center;
    font-size: 20px;
    cursor: pointer;
    color: darkslategrey;
    overflow: hidden;
    transition: 0.5s;
    opacity: 0.7;
    border: 1px solid white;
    width: 95px;
    height: 75px;
    margin: 10px 10px;
  }

  header:hover {
    background-color: transparent;
    color:aliceblue;
  }

  nav {
    align-self: flex-start;
  }

  .image {
   max-height: 350px;
   padding: 0px 20px;
   max-width: 400px;
  }

.sidenav  {
  display: flex;
  flex-direction: column;
  text-align: center;
  align-items: center;
  align-self: center;
  padding: 30px 40px;
  color: black;
  width: 300px;
  height: 520px;
  }

  .content {
    display: flex;
    height: 400px;
    background-color: aliceblue;
    width: 1100px;
    opacity: 0.7;
    color: black;
    padding: 20px 20px;
    text-align: justify;
    margin: 100px 10px;
  }

  .menu_btn{
    border: 1px solid transparent;
    width: 180px;
    height: 100px;
    padding: 30px 30px;
    text-align: center;
    line-height: 10px;
    font-size: 25px;
    text-decoration: none;
    list-style-type: none;
    color: black;
    gap: 10px;
  }

.text-content {
    font-size: 25px;
}

  a {
    color: black;
  }
  
  a:hover {
    color: aliceblue;
    background-color: transparent;
    border: 1px solid grey; 
    padding: 15px;
    border-radius: 15px;
   }


   @media screen and (max-width: 375px) {
    body {
      overflow: auto;
     }
    header {
        display: none;
    }
    
    .sidenav{
      align-self: center;
    }
    .content{
        flex-direction: column;
        height: 700px;
        text-align: justify;
    }
    .image {
        flex-direction: column;
    }
    .menu_btn{
      font-size: 18px;
     }
  }

   @media screen and (max-width: 600px) {
   body {
    overflow: auto;
   }
    header {
        display: none;
    }
    .sidenav {
        align-self: center;
        width: 250px;
        height: 400px;
    }
    .content{
        flex-direction: column;
        
    }
    .image {
        flex-direction: column;
    }
    .text-content {
      font-size: 5px;
     }
     .menu_btn{
      font-size: 20px;
     }
  }

  @media screen and (max-width: 768px) {
    body {
     overflow: auto;
    }
     header {
         display: none;
     }
     .sidenav {
         align-self: center;
         width: 250px;
         height: 400px;
     }
     .content{
         flex-direction: column;
     }
     .text-content {
      font-size: 15px;
     }
     .menu_btn{
      font-size: 18px;
     }
   }

  @media screen and (max-width: 850px) {
  
    header {
        display: none;
    }
    .sidenav {
        align-self: center;
        width: 250px;
        height: 400px;
    }
    .content{
        flex-direction: column;
        height: 500px;
    }
    .image {
        flex-direction: column;
    }
    .text-content {
      font-size: 20px;
     }
     .menu_btn{
      font-size: 20px;
     }
  } 

  @media (max-width: 1154px) {
    body {
     overflow: scroll;
    }
     header {
         display: none;
     }
     .sidenav {
         align-self: center;
     }
     .content {
      flex-direction: column;
      height: 700px;
      width: 700px;
      
     }
     .image {
      overflow: scroll;
     }
     .text-content {
      font-size: 23px;
     }
    }

  @media (max-width: 1194px) {
    body {
     overflow: auto;
    }
     header {
         display: none;
     }
     .sidenav {
         align-self: center;
     }
     .content {
      flex-direction: column;
      height: 650px;
    
     }
     .image {
         flex-direction: column;
         align-self: center;
     }
   } 
 

  @media (max-width: 1299px) {
   body {
    overflow: auto;
   }
    header {
        display: none;
    }
    .sidenav {
        align-self: center;
    }
    .image {
        flex-direction: column;
    }
  }