@media screen and (min-width: 1024px) {
  /* デスクトップ用のスタイル */
  .content {
    width: 800px; /* デスクトップの幅 */
  }
}


/* Under Line */
.under1 {
  text-decoration: underline;
}

.under2 {
  border-bottom:3px double  #000000;
}

.under3 {
  background: linear-gradient(transparent 50%, #a8eaff 50%);
}

.under4 {    
  border-bottom: 2px dotted #000;
  text-decoration: none;
}

/* hightlight */
.highlight-fill-blue{
  background-color: #a8eaff;
  display: inline; /* または display: inline-block; */
}

.highlight-row-blue{
  display: block;
  width: 100%;
  background-color: #a8eaff;
}

.highlight-underline-blue {
  background: linear-gradient(transparent 50%, #a8eaff 50%);
}