#exercise{     
  clear:both;
  max-width: 800px; 
  margin: 0px auto;       
  min-height:600px;
  text-align: center;
  background-color: transparent;
  border:0px;
}

#exercise #plan{
  text-align: center;
  background-color: white;
  margin-bottom: 10px;
}

#exercise .instruction{
  display: inline-block;  
  font-size: 28px;  
  vertical-align: top;
  padding:20px;
  margin-left: 30px;
  text-align: left;  
}
#exercise .instruction li{
  font-size: 20px;
  line-height: 1.3em;
}

#exercise table.tabulka{
  display: inline-block;
  border-spacing: 0px;
  border-collapse: separate;
  background-color: white;
  vertical-align: top;
  padding:20px;
  width: auto;
}

#exercise table.tabulka td{
  padding:0px;
  width:60px;  
  height:60px;  
  line-height: 60px;
  font-size: 28px;
  text-align: center;
  border-bottom: 0px;
  border:1px solid #e1e7e6;  
}

#exercise table.tabulka td.cell{

}

#exercise table.tabulka td.cell:hover{
  background-color:#f7f9f9; 
  cursor: pointer;
}

#exercise table.tabulka td.shown{
  background-color: #91d2fd;  
}

#exercise table.tabulka td.correct{
  background-color: #35cc73;
}

#exercise .tlacitko-control{
  display: inline-block;
  margin: 5px;  
  margin-top: 20px;
  font-size: 18px;    
  width: 150px;      
  text-align:center;  
  border-radius:2px;  
  line-height: 50px;  
  cursor: pointer;

  background-color: #e0e0e2;
  color: var(--darkGray);
}

#exercise .tlacitko-control:hover{ 
  color:white; 
  background-color:#2ecc71; 
}

#exercise .tlacitko-control.disabled{ 
  color:white;
  background-color:#e6e8ea;  
}

#exercise #rules{  
  display: inline-block;
  max-width: 600px;
  background-color: white;
  border:1px solid #2980b9;
  border-radius: 3px;
  padding:15px;  
  margin-bottom: 15px;
  text-align: left;
}

#exercise #explanation{
  font-size: 18px;
  font-weight: 400;
  background-color: white;
  border:1px solid #2980b9;
  border-radius: 3px;
  padding:10px;
  text-align: left;
  display: none;
}

#backOverview{
  text-decoration:none;
}