.course {
    min-height: 100vh;
   
    background-attachment: fixed;
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    z-index: 0;
    overflow: hidden;
    display: block;
    margin: auto;  
    

  }
   
    .course .box-container {
      display: flex;
      flex-direction: row;
      justify-content: center;
      align-items: center;
      flex-wrap: wrap;
      max-width:1500px ;
      margin: auto;
      margin-top: 80px;
    }
    
    .course .box-container .box {
      min-height: 20rem;
      max-width: 130rem;
      background: #fff;
      text-align: center;
      margin: 2rem;
      cursor: pointer;
      
    }
    
    .course .box-container .box .video {
    
      margin: 1.5rem auto;
      
    }

    .course .box-container .box .video iframe{
        border-radius: 5px;
    }
    
    .course .box-container .box h3 {
      font-size: 30px;
      color: black;
      transition: 0.2s;
      text-transform: none;
      padding-top: 10px;
      padding-bottom: 10px;
      font-weight: bold;
      text-align: center;
    }
    
 

    .course .box-container .box h4 {
      font-size: 18px;
      color: black;
      transition: 0.2s;
      text-transform: none;
      padding-top: 20px;
      padding-bottom: 10px;
      font-weight: 400;
      text-align: left;
      font-weight: bold;
    }

    .course .box-container .box h5 {
      font-size: 16px;
      color: black;
      transition: 0.2s;
      text-transform: none;
      padding-top: 10px;
      padding-bottom: 10px;
      font-weight: 400;
      text-align: left;
    }
    
    .course .box-container .box h6 {
      font-size: 13px;
     
      color: #666;
      margin-bottom: 10px;
      text-align: center;
     
    }

    .course .box-container .box button{
      background-color: white;
      width: 300px;
      border-radius: 5px;
      cursor: pointer;
      box-shadow: 0 0.3rem 0.5rem rgba(0, 0, 0, 0.5);
      display: block;
      height: 50px;
    font-size: 17px;
      display: block;
      margin: 20px auto;
    }

    .course .box-container .box button:hover{
      transition: 0.5s;
      box-shadow: none;

    }

    @media (max-width: 580px) {
        .course .box-container .box .video iframe{
            width: 350px;
            height: 250px;
        }
        

      }          
          
  
      @media (max-width: 500px) { 
        .course .box-container .box button{
          width: 80%;
        }


  }
  
  @media (max-width: 360px) { 
    .course .box-container .box img {
     
      width: 250px;
    
    }

    .course .box-container .box h3 {
      font-size: 20px;
    }
    .course .box-container .box h4 {
      font-size: 16px;
    }
    .course .box-container .box h5 {
        font-size: 13px;
      }

      .course .box-container .box button{
       
        width: 250px;
        height: 45px;
        
      font-size: 15px;
        
      }

    .course .box-container .box .video iframe{
        width: 250px;
        height: 150px;
    }
}

  @media (min-width: 500px){
  
  #backToTop {
    display: none; /* Skryté ve výchozím stavu */
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 199;
    border: none;
    outline: none;
    background-color: blue;
    color: white;
    cursor: pointer;
    padding: 15px 20px;
    border-radius: 50%;
    font-size: 20px;
  }
  
  #backToTop:hover {
    background-color: #555;
  }}
  
  @media (max-width: 500px){
    #backToTop{
      opacity: 0;
    }
    .main-heading button{
      width: 250px;
      font-size: 15px;
    }
    .course .hide{
        display: none;
      }
  }

  @media (max-width: 299px){
    .course .box-container .box button{
        font-size: 1.9rem;
    }
  }