/* リセットCSS */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* 基本設定 */
body {
  font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
  line-height: 1.6;
  color: #333;
}

/* ヘッダー */
header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  background-color: #ffffff;
  color: #fff;
  padding: 20px 0;
}

header h1 {
  text-align: left;
  font-size: 36px;
}

nav ul {
  display: flex;
  justify-content: center;
  list-style: none;
  margin-top: 10px;
}

nav ul li {
  position: relative;
  margin: 0 25px;
}

nav ul li a {
  color: #000000;
  text-decoration: none;
  font-size: 20px;
}

nav ul li a:hover {
  text-decoration: underline;
}

nav ul li .dropdown-content {
  display: none;
  position: absolute;
  background-color: #ffffff;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
}

nav ul li .dropdown-content a {
  color: black;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
}

nav ul li .dropdown-content a:hover {
  background-color: #ddd;
}

nav ul li:hover .dropdown-content {
  display: block;
}

img.logo {
  width: 36px;
  height: 36px;
  }
  

/* メインコンテンツ */
main {
  padding: 40px 20px;
}

main h1 {
  font-size: 36px;
  margin-bottom: 20px;
}

main h2 {
  font-size: 28px;
  margin-bottom: 10px;
}

article {
  max-width: 1000px;
  margin: 0 auto;
}

section {
  margin-bottom: 30px;
}

.imgbox {
  text-align: center;
  padding: 60px 10px 50px 10px;
}

.p_img{
  width: 3%;
  vertical-align: middle;
}

.button {
  display: inline-block;
  background-color: #0066cc;
  color: #fff;
  padding: 10px 20px;
  text-decoration: none;
  font-size: 24px;
  margin-top: 20px;
}

.button:hover {
  background-color: #004999;
}

.buttonsub {
  display: inline-block;
  background-color: #7a7a7a;
  color: #fff;
  padding: 10px 20px;
  text-decoration: none;
  font-size: 24px;
  margin-top: 20px;
}

.buttonsub:hover {
  background-color: #5b5b5b;
}

/* フッター */
footer {
  background-color: #f4f4f4;
  color: #666666;
  text-align: center;
  padding: 15px 0;

}

/* レスポンシブ対応 縦画面 */
@media (orientation: portrait){
  
  nav ul li {
    margin: 0 25px;
  }
  
  nav ul li a {
    color: #000000;
    text-decoration: none;
    font-size: 30px;
  }

  img.logo {
    width: 50px;
    height: 50px;
    }
}

.year-buttons {
  display: flex;
  justify-content: left;
  margin: 10px 0;
}
.year-buttons button {
  background-color: #7a7a7a;
  color: #fff;
  margin: 0 10px;
  padding: 10px 30px;
  text-decoration: none;
  font-size: 18px; /* フォントサイズを大きく設定 */
}
.year-buttons button:hover {
  background-color: #5b5b5b;
}