body {
  margin: 0;
  background: #f4f4f4;
  font-family: sans-serif;
}

/* 基本スタイル */
#header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  height: 80px;
  background: #fff;
  position: relative;
  z-index: 100;
}

#header img {
  height: 60px;
}

.nav a {
  text-decoration: none;
  color: #333;
  margin: 0 15px;
}

/* ハンバーガーメニュー */
.menu-btn {
  display: none; /* PCは非表示 */
  cursor: pointer;
  width: 30px;
  height: 25px;
  flex-direction: column;
  justify-content: space-between;
}

.menu-btn span {
  height: 4px;
  background: black;
  border-radius: 2px;
}

/* モバイル用スライドメニュー */
.nav {
  position: fixed;
  top: 0;
  right: 0;
  height: 100vh;
  width: 250px;
  background-color: #fff;
  box-shadow: -2px 0 8px rgba(0,0,0,0.2);
  display: flex;
  flex-direction: column;
  padding-top: 70px;
  transform: translateX(100%);
  transition: transform 0.3s ease-in-out;
  z-index: 1001;
}

.nav.show {
  transform: translateX(0);
}

.close-btn {
  position: absolute;
  top: 15px;
  right: 15px;
  font-size: 28px;
  background: none;
  border: none;
  cursor: pointer;
}

/* ========== PC用 横並び ========== */
@media (min-width: 769px) {
  .nav {
    position: static;
    flex-direction: row;
    height: auto;
    width: auto;
    transform: none;
    box-shadow: none;
    padding: 0;
  }

  .nav a {
    margin: 0 15px;
  }

  .close-btn {
    display: none;
  }

  .menu-btn {
    display: none;
  }
}

/* ========== モバイル用 ========== */
@media (max-width: 768px) {
  .menu-btn {
    display: flex;
  }

  .nav a {
    padding: 15px 20px;
    border-bottom: 1px solid #eee;
  }
}

.hero {
  background-color: #111;
}

.image_container,
.image_container2,
.image_container3,
.image_container4 {
  position: relative;
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  color: white;
  background-color: #333; /* 画像がない場合の背景色 */
}

.image_container {
  /* 下に向かって透明にフェード */
  -webkit-mask-image: linear-gradient(to bottom, black 80%, transparent 100%);
  mask-image: linear-gradient(to bottom, black 80%, transparent 100%);
}

.image_container::before,
.image_container2::before,
.image_container3::before,
.image_container4::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.5); /* 画像を少し暗くして文字を見やすく */
}

.image_container .content,
.image_container2 .content,
.image_container3 .content,
.image_container4 .content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  padding: 20px;
}

.image_container h1,
.image_container2 h1,
.image_container3 h1,
.image_container4 h1 {
  font-size: 3rem;
  margin-bottom: 15px;
  line-height: 1.2;
}

/* 個別設定 */
.image_container {
  height: 90vh;
  background-image: url('images/keio2.jpg');
}

.image_container2 {
  height: 60vh;
  background-image: url('images/keio4.jpg');
}

.image_container3 {
  height: 60vh;
  background-image: url('images/keio1.jpg');
}

.image_container4 {
  height: 60vh;
  background-image: url('images/keio3.jpg');
}

.title {
  font-size: 2.5rem;
  margin-bottom: 20px;
}

.mvv {
  color: white;
  text-align: center;
  padding: 40px 20px 30px; /* 上下左右に余白を追加 */
  border-bottom: #0077cc 6px solid;
}

.mvv .content {
  width: 80%;
  max-width: 700px;
  margin: 0 auto; /* 中央寄せ */
}

.mvv h2 {
  margin-top: 10px;
  margin-bottom: 10px;
  font-size: 2rem;
}

.mvv p {
  font-size: 1.1rem;
  margin: 0 0 50px;
}


#main {
  width: 80%;
  max-width: 820px;
  margin: 0 auto;
  padding-top: 10px;
}

.explanation p{
  font-size: 1.1rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

/* ===== about_us 全体 ===== */
.about_us {
  max-width: 1000px;
  margin: 50px auto;
  padding: 0 20px;
  font-family: "Helvetica Neue", Arial, sans-serif;
  color: #333;
}

/* ===== SMIFの必要性 ===== */
#main h2 {
  font-size: 1.8rem;
  margin-top: 50px;
  margin-bottom: 15px;
  border-left: 4px solid #0077cc;
  padding-left: 10px;
}

h3 {
  font-size: 2rem;           /* h2より少し小さめ */
  margin-top: 50px;            /* 上マージンはh2より少し少なめ */
  margin-bottom: 20px;         /* 下マージンを少し調整 */
  padding-left: 3px;           /* ボーダーから文字までのスペース */
  color: #333;                 /* h2より少し落ち着いた色でもOK */
}

/* メンバーリスト全体 */
.member-list {
  display: flex;
  flex-direction: column; /* デフォルトは縦並び（スマホ） */
  gap: 20px;
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 個々のメンバーカード */
.member {
  background: #f9f9f9;
  border-radius: 12px;
  overflow: hidden;
  transition: transform 0.3s, box-shadow 0.3s;
}

.member:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.15);
}

/* メンバー内の画像＋説明のコンテナ */
.member-inner {
  display: flex;
  flex-direction: column; /* デフォルトは縦並び */
  align-items: center;
  text-align: center;
  padding: 20px;
}

.member img {
  width: 100%;
  height: auto;
  object-fit: contain;
  max-height: 350px;
  border-radius: 12px;
}

.member a {
  text-decoration: none; /* リンクの下線を消す */
  color: inherit;        /* 親の文字色を継承 */
}

.member-info h3 {
  font-size: 1.6rem;
  margin-bottom: 10px;
}

.member-info p {
  font-size: 1rem;
  color: #555;
}

/* ===== PC幅で横並び ===== */
@media (min-width: 767px) {
  .member-list {
    flex-direction: row; /* 横並び */
    flex-wrap: wrap;
    justify-content: space-between;
  }

  .member {
    flex: 1 1 30%; /* 3列並べるイメージ */
  }

  .member-inner {
    flex-direction: column; /* カード内は縦並びのまま */
    text-align: center;
  }
}

.grid-container {
  font-size: 0.9rem;
  display: grid;
  gap: 15px;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.grid-container h4 {
  font-size: 1.1rem;
}

.block_img {
  padding: 20px;
  background-color: #fff;
  display: flex;
  flex-direction: column;
  border-radius: 5px;
  justify-content: center;
  align-items: center;
  aspect-ratio: 2 / 3;
  text-align: center;
}

.block_text {
  background-color: #fff;
  padding: 20px;
  border-radius: 5px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  aspect-ratio: 2 / 3;
  text-align: center;
}

@media (max-width: 960px) {
  .block_img {
    aspect-ratio: 1 / 1;
  }

  .block_text {
    aspect-ratio: 1 / 1;
  }
}

.block_title {
  font-size: 1.2rem;
  font-weight: bold;
  margin-bottom: 10px;
}

.block_discription p{
  font-size: 1rem;
  color: #333;
  line-height: 1.4;
}

.block_img img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

.skill-list {
  font-size: 1rem;
  list-style-type: none;
  padding: 0;
  margin: 0;
}

.chart {
  width: 80%;
  height: 80px;
  background-color: #e0e0e0;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  color: #555;
  margin-bottom: 4px;
}

.reports a {
  display: block;
  font-size: 12px;
  color: #1a73e8;
  text-decoration: none;
  margin: 2px 0;
}

.reports a:hover {
  text-decoration: underline;
}


/* グリッド */
.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 16px;
}
/* 最新レポートは大きめカード */
.grid.latest > article {
  grid-column: span 12;
}
@media (min-width: 720px) {
  .grid.latest > article { grid-column: span 6; }
}
/* バックナンバーは小さめカード */
.grid.archive > article {
  grid-column: span 12;
}
@media (min-width: 600px) {
  .grid.archive > article { grid-column: span 6; }
}
@media (min-width: 960px) {
  .grid.archive > article { grid-column: span 4; }
}

/* カード */
article {
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius);
  overflow: clip;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s;
  box-shadow: 0 6px 24px rgba(0,0,0,0.25);
}
article:hover {
  transform: translateY(-3px);
  border-color: rgba(106,169,255,0.35);
  box-shadow: 0 10px 28px rgba(106,169,255,0.15), 0 10px 30px rgba(0,0,0,0.35);
}
a.card {
  display: grid;
  grid-template-rows: auto 1fr;
  color: inherit; text-decoration: none; height: 100%;
}
.thumb {
  position: relative; aspect-ratio: 16/9; overflow: hidden;
  background: #0c0f1a;
}
.thumb img {
  width: 100%; height: 100%; object-fit: cover;
  display: block; filter: saturate(1.05);
  transition: transform .35s ease;
}
article:hover .thumb img { transform: scale(1.03); }
.badge {
  position: absolute; left: 10px; top: 10px;
  padding: 4px 10px; border-radius: 999px; font-size: 12px;
  background: rgba(10, 122, 255, 0.85); color: white;
  backdrop-filter: blur(6px);
  border: 1px solid rgba(255,255,255,0.18);
}
.report_content,
.report_content_back {
  padding: 14px 14px 16px;
  display: grid; gap: 8px;
}

.report_content h3 {
  margin: 0; font-size: 2rem; line-height: 1.4;
}

.report_content_back h3 {
  margin: 0; font-size: 1rem; line-height: 1.4;
}

.meta {
  display: flex; gap: 10px; align-items: center; color: var(--muted);
  font-size: 12px;
}
.abstract {
  margin: 0; color: #555; font-size: 14px;
}
.more {
  margin-top: 6px; font-size: 13px; color: var(--accent);
}

/* アクセシビリティ（キーボード用） */
a.card:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 2px;
}

.report_article h1 {
      font-size: 28px;
      margin-bottom: 10px;
    }

.report_article .meta {
  color: #666; font-size: 14px; margin-bottom: 20px;
    }

.report_article img{
  width: 100%; border-radius: 8px; margin: 20px 0;
    }

 .report_article h2 {
  margin-top: 32px;
  font-size: 22px;
  border-left: 4px solid #337ab7;
  padding-left: 8px;
    }

.report_article p { margin: 12px 0; }

.news {
  margin-top: 30px;
}

.news_title {
  border-bottom: 1px solid #ddd;
  padding: 16px 0;
}
.news_title:last-child {
  border-bottom: none;
}
.news_title .date {
  font-size: 14px;
  color: #666;
}
.news_title h3 {
  margin: 6px 0;
  font-size: 20px;
}
.news_title p {
  margin: 8px 0;
}



#about_table {
  max-width: 500px;
  margin: 50px auto 50px;
  padding: 10px;
}

#about_table table {
  width: 100%;
  border-collapse: collapse;
  font-family: "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

#about_table th,
#about_table td {
  border: 1px solid #ddd;
  padding: 12px 16px;
  text-align: left;
}

#about_table th {
  background-color: #f7f7f7;
  font-weight: bold;
  width: 30%;
  color: #333;
}

#about_table td {
  background-color: #fff;
  color: #444;
}

#footer {
  background-color: #111;
  color: #fff;
  padding: 30px 20px;
  margin-top: 50px;
}

.footer-container {
  max-width: 1000px;
  margin: 0 auto;
  text-align: center;
}

.footer-logo img {
  height: 50px;
  margin-bottom: 15px;
}

.footer-links {
  margin: 15px 0;
}

.footer-links a {
  color: #ddd;
  text-decoration: none;
  margin: 0 12px;
  font-size: 15px;
}

.footer-links a:hover {
  color: #fff;
  text-decoration: underline;
}

.footer-copy {
  font-size: 13px;
  color: #aaa;
}