.column {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 20px;
}

.column-item, .is_column-item { flex: 1; }


section[class^="region"] > details > summary {
  list-style: none;       
  position: relative;
  padding-left: 36px;    
  cursor: pointer;
}
section[class^="region"] > details > summary::before {
  content: "+";
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-weight: 700;
  font-size: 1.2em;
  line-height: 1;
  color: #000;      
}


section[class^="region"] > details[open] > summary::before {
  content: "－";
}





.column .column-item > details > summary {
  list-style: none;     
  position: relative;
  padding-left: 32px;   
  cursor: pointer;
}

.column .column-item > details > summary::before {
  content: "+";
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  font-weight: 700;
  font-size: 1.1em;
  line-height: 1;
  color: #000;  
}


.column .column-item > details[open] > summary::before {
  content: "－";
}


@media screen and (max-width: 768px) {
  .column {
    flex-direction: column;
  }
}