body {
  background-color: white;
  color: #0d482c;
  font-family: Arial, sans-serif;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: #66dc57;
  padding: 20px;
  color: white;
}

header #logo {
  width: 100px;
}

header #login-btn {
  color: white;
  text-decoration: none;
}

main #content {
  margin: 20px;
}

.main-section{
  border: 1px solid #66dc57;
  padding-top:10px;
  padding-left: 20px;
  padding-right: 20px;
  padding-bottom: 20px;

  margin-bottom: 20px;
}
.main-section img{
  width: 100%;
  margin-bottom: 20px;
}
.main-section h3 {
  /* display: inline-block;*/
  position: relative; 
  /* margin-right:; */
  margin-top: 0.2em;
}
.main-section h3::after {
  content: '';
  position: absolute;
  width: 60%; /* 下線の長さを親要素の50%に設定 */
  height: 1px; /* 下線の厚み */
  background-color: black; /* 下線の色 */
  bottom: 0;
  left: 0; /* 左端から開始 */
}

.infomationSec {
  padding-bottom: 10px;
}

.start-button {
  display: block;
  background-color: #66dc57;
  color: white;
  margin: 20px auto;
  padding: 15px 30px;
  text-decoration: none;
  text-align: center;
  border-radius: 5px;
}

footer {
  text-align: center;
  padding: 20px;
  border-top: 2px solid #66dc57;
}

.headerText {
  display: block;
  font-size: 1.5em;
  margin-block-start: 0.3em;
  margin-block-end: 0.3em;
  margin-inline-start: 0px;
  margin-inline-end: 0px;
  font-weight: bold;
  unicode-bidi: isolate;
}

a {
  color: #0d482c; /* ブラック */
  text-decoration: none; /* 下線を消す */
}

a:visited {
  color: #0d482c; /* 訪問済みでも色をブラックに保つ */
}

a:hover {
  color: #0b7644; /* ホバー時も色をブラックに保つ */
}

a:active {
  color: #0b7644; /* クリック中も色をブラックに保つ */
}

.smDate{
  font-size:small;
  margin-left:1em;
}