details{
  display:block;
  background: #fff;
  width: auto;
  box-shadow: 0 10px 15px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  border-radius: 8px;
  overflow:hidden;
  margin-bottom: 1.5rem;
  text-align: left;
}
summary::-webkit-details-marker{display:none;}
summary::-moz-list-bullet{list-style-type:none;}
summary::marker{display:none;} 
summary {
   display:block;
   padding: .3em 1em .3em .9em;
   border-bottom: 1px solid #e2e8f0;
   font-size:2em;
   cursor: pointer;
   position: relative;
   color: #000; text-align: left; margin-left:10px; line-height: 1.5;
}
.obraz p {text-align: justify;}
summary:before {  
  top: 0.7em;
  right: .3em;
  color: black;
  background: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0Ij48cGF0aCBkPSJNMTYuNTkgOC41OUwxMiAxMy4xNyA3LjQxIDguNTkgNiAxMGw2IDYgNi02eiIvPjxwYXRoIGQ9Ik0wIDBoMjR2MjRIMHoiIGZpbGw9Im5vbmUiLz48L3N2Zz4=") no-repeat 50% 50% / 1em 1em;
  width: 1em;
  height: 1em;  
  content: "";
  position: absolute;
  transition: transform .5s;
}
details[open] > summary:before {
  transform: scale(1,-1);
}
summary ~ * {
   padding: 0 1em 10px 1.4em; color: black; font-size: 16px;
}
details[open] summary ~ *{ 
  animation: sweep .5s ease-in-out;
}
@keyframes sweep {
  0%    {opacity: 0;}
  100%  {opacity: 1;}
}
summary:focus {
  outline:0;
  box-shadow: inset 0 0 1px rgba(0,0,0,0.3), inset 0 0 2px rgba(0,0,0,0.3);
}