body {
  font-family: "メイリオ", Meiryo, "ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", "游ゴシック", "Yu Gothic", sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #fff;
  font-size: 16px;
}

#container {
  max-width: 800px;
  width: 100%;
  margin: 0 auto;
  padding: 20px;
  box-sizing: border-box;
}

.top-logos {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 30px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.top-logos img {
  height: 60px;
  object-fit: contain;
  filter: grayscale(20%);
  transition: filter 0.3s;
}

.top-logos img:hover {
  filter: grayscale(0%);
}

h1 {
  font-weight: bold;
  text-align: center;
  margin-bottom: 20px;
  line-height: 1.4;
  font-size: 24px;
}

.eng-button {
  display: inline-block;
  margin: 20px 0;
  padding: 10px 20px;
  background-color: #000;
  color: #fff;
  text-decoration: none;
  border-radius: 5px;
  font-weight: bold;
  transition: background-color 0.3s;
}

.eng-button:hover {
  background-color: #222;
}

h2.gradient-header {
  max-width: 800px;
  margin: 30px auto 15px auto;
  padding: 6px 20px;
  border-radius: 20px;
  background: linear-gradient(90deg, #0e7e81 0%, #6db94e 100%);
  color: white;
  text-align: center;
  font-weight: bold;
  font-size: 20px;
}

h3 {
  text-align: center;
  margin-top: 20px;
  margin-bottom: 10px;
}

.purpose-list {
  columns: 2;
  column-gap: 40px;
  max-width: 700px;
  margin: 0 auto 20px auto;
  padding-left: 20px;
}

#news {
  margin-bottom: 20px;
}

.news-item {
  margin-bottom: 10px;
}

#news-toggle-buttons {
  text-align: center;
}

#news-toggle-buttons button {
  margin: 10px 5px;
  padding: 8px 16px;
  font-size: 14px;
  cursor: pointer;
  background-color: #f0f0f0;
  color: #666;
  border: 1px solid #ccc;
  border-radius: 4px;
  transition: background-color 0.3s, color 0.3s;
}

#news-toggle-buttons button:hover {
  background-color: #e0e0e0;
  color: #444;
}

.partner-logos {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
  gap: 20px;
  max-width: 800px;
  margin: 10px auto 40px auto;
  justify-items: center;
}

.partner-logos img {
  width: 120px;
  height: 60px;
  object-fit: contain;
  filter: grayscale(20%);
  transition: filter 0.3s;
  cursor: pointer;
}

.partner-logos img:hover {
  filter: grayscale(0%);
}

.footer {
  text-align: center;
  margin-top: 30px;
}

.footer a {
  display: inline-block;
  background-color: #000;
  color: #fff;
  padding: 10px 20px;
  border-radius: 5px;
  font-weight: bold;
  text-decoration: none;
  transition: background-color 0.3s;
}

.footer a:hover {
  background-color: #222;
}

#scrollTopBtn {
  display: none;
  position: fixed;
  bottom: 40px;
  right: 40px;
  width: 50px;
  height: 50px;
  background-color: #000;
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  transition: background-color 0.3s;
}

#scrollTopBtn:hover {
  background-color: #222;
}

#scrollTopBtn svg {
  width: 24px;
  height: 24px;
  fill: #fff;
}

/* ====== 研究メンバー表示（固定3列＋モバイル対応） ====== */
.member-section {
  max-width: 800px;
  width: 100%;
  margin: 0 auto;
  padding: 10px 0 30px 0;
}

.members-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 30px;
}

.member-card {
  background-color: #f9f9f9;
  border-radius: 10px;
  text-align: center;
  padding: 10px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
  transition: transform 0.2s ease;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  height: 100%;
  box-sizing: border-box;
}

.member-card:hover {
  transform: translateY(-4px);
}

.member-card img {
  width: 100%;
  max-width: 150px;
  height: auto;
  object-fit: cover;
  border-radius: 8px;
  margin-bottom: 10px;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.member-card p {
  font-size: 14px;
  line-height: 1.4;
  margin: 0;
}

.member-card a {
  color: #0e7e81;
  text-decoration: none;
  font-weight: bold;
}

.member-card a:hover {
  text-decoration: underline;
}

.publications-list {
  padding-left: 1.5em;
  list-style-type: disc;
  line-height: 1.6;
  margin-bottom: 2em;
}

.publications-list li {
  margin-bottom: 1em;
}

@media screen and (max-width: 768px) {
  .purpose-list {
    columns: 1;
  }

  .members-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media screen and (max-width: 480px) {
  body {
    font-size: 14px;
  }

  h1 {
    font-size: 18px;
  }

  h2.gradient-header {
    font-size: 16px;
    padding: 4px 10px;
  }

  .members-grid {
    grid-template-columns: repeat(1, 1fr);
  }

  .nav-button {
    font-size: 14px;
    padding: 0.4em 0.8em;
  }
}