/* --- Basic Setup --- */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.7;
    color: #3a3a3a;
    background-color: #f4f7f6;
    margin: 0;
}
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

/* --- Top Header (Profile & Navigation) --- */
.site-header{
  /* 画像 + 透過色オーバーレイ */
  background-image:
    linear-gradient(rgba(0,0,0,0.35), rgba(0,0,0,0.35)), /* 透過色 */
    url("img/matterhorn.jpg");                           /* 背景画像 */
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;

  /* 既存レイアウトは踏襲 */
  padding: 60px 40px;
  margin: 30px 0;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.07);
  text-align: center;

  /* 可読性のため文字を白に */
  color: #fff;
}
.site-header h1{ color:#fff; }
.site-header .affiliation{ color: rgba(255,255,255,0.9); }
.main-nav a{ color:#fff; }
.main-nav a:hover{ color:#ffd166; } /* 好みで */

.profile-pic {
    width: 160px;
    height: 160px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 20px;
    border: 5px solid #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.site-header h1 {
    font-size: 2.2rem;
    margin: 10px 0 5px 0;
    color: #2c3e50;
}
.site-header .affiliation {
    font-size: 1.1rem;
    color: #7f8c8d;
    margin: 0 0 30px 0;
}

/* --- Navigation Menu --- */
.main-nav {
    border-top: 1px solid #ecf0f1;
    padding-top: 25px;
}
.main-nav a {
    color: #47c7c3ff;
    text-decoration: none;
    font-weight: 500;
    margin: 0 12px;
    transition: color 0.3s;
    font-size: 1rem;
}
.main-nav a:hover {
    color: #e74c3c;
}

/* --- Main Content Area --- */
main {
    background-color: #ffffff;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.07);
}
section {
    margin-bottom: 50px;
}
h2 {
    font-size: 1.8rem;
    color: #2c3e50;
    border-bottom: 3px solid #47c7c3ff;
    padding-bottom: 10px;
    margin-top: 0;
    margin-bottom: 25px;
}
p, li {
    font-size: 1.05rem;
}

/* --- Publication & Project Items --- */
.item-list .item {
    margin-bottom: 25px;
    padding-bottom: 25px;
    border-bottom: 1px solid #ecf0f1;
}
.item-list .item:last-child {
    border-bottom: none;
    padding-bottom: 0;
    margin-bottom: 0;
}
.item-list p {
    margin: 5px 0;
}
.jump-button {
    display: inline-block;
    background-color: #47c7c3ff;
    color: #fff;
    padding: 1.5px 12px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: bold;
    font-size: 0.9rem;
    margin-left: 10px;
    transition: background-color 0.3s;
}
.jump-button:hover {
    background-color: #47c7c3ff;
}

/* --- Contact Links --- */
.contact-links a {
    display: inline-block;
    margin-right: 20px;
    color: #47c7c3ff;
    font-weight: bold;
    text-decoration: none;
}
.contact-links a:hover {
    text-decoration: underline;
}

/* --- Footer --- */
.site-footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    font-size: 0.9rem;
    color: #95a5a6;
}

/* --- 強制的にヘッダー文字を白に --- */
.site-header,
.site-header h1,
.site-header p,
.site-header a,
.site-header .affiliation {
  color: #fff !important;
}

.site-header a:hover {
  color: #ffd166 !important; /* 任意のアクセント色 */
}

/* 背景の透過画像設定も念のため再掲 */
.site-header {
  background-image:
    linear-gradient(rgba(0,0,0,0.35), rgba(0,0,0,0.35)),
    url("img/matterhorn.jpg");
  background-size: cover;
  background-position: 20% 75%;
  background-repeat: no-repeat;
  text-align: center;
  padding: 60px 40px;
}

/* セクションジャンプ */
.section-jump{
  display:flex; gap:10px; flex-wrap:wrap;
  justify-content:center; margin:16px 0 24px;
}
.jump-btn{
  display:inline-block; padding:8px 14px;
  background:#444; color:#fff; text-decoration:none;
  border-radius:6px; font-size:.95rem;
}
.jump-btn:hover{ background:#666; }

/* アンカー位置の余白（見出しが被る時に有効） */
#all-papers, #book{ scroll-margin-top: 80px; }

/* なめらかなスクロール */
html{ scroll-behavior:smooth; }

/* --- Courses Section --- */
.course-list {
  list-style-type: none;
  padding: 0;
  margin: 0;
  color: #444;
}

.course-list li strong {
  display: inline-block;
  width: 110px;
  color: #444;
}

/* --- Other Academic Activities --- */
#activities h3 {
  margin-top: 28px;
  border-bottom: 2px solid #ccc;
  padding-bottom: 4px;
  color: #444;
}
.activity-list {
  margin: 8px 0 16px 20px;
  color: #444;
  font-size: 0.95rem;
}
.activity-list li {
  margin-bottom: 6px;
  line-height: 1.5;
}