/* ================================
   CSS Variables
   ================================ */
:root {
  /* Colors */
  --accent: #2a8c82;
  --accent-dark: #1f6b63;

  --text-main: #333;
  --text-light: #555;

  --bg-main: #ffffff;
  --bg-panel: #f5f5f5;
  --bg-border: #ddd;

  /* Dark Mode Colors */
  --bg-dark: #121212;
  --text-dark: #e5e5e5;
  --panel-dark: #1e1e1e;
  --border-dark: #333;

  /* Layout */
  --sidebar-width: 260px;
  --content-padding: 3rem;
  --sidebar-padding: 2rem 1.5rem;

  /* Typography */
  --line-height-main: 1.9;
  --font-main: "Hiragino Mincho ProN", "Yu Mincho", serif;
}

/* ================================
   Base Styles
   ================================ */

/* --- 基本設定 --- */
body {
  font-family: var(--font-main);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: var(--line-height-main);
  margin: 0;
  padding: 0;
}

/* --- ヘッダー --- */
header {
  background-color: var(--accent);
  color: white;
  padding: 1.8rem 3rem;
}

.site-title {
  font-size: 1.9rem;
  letter-spacing: 0.05em;
  margin: 0;
}

/* ================================
   Navigation (Accordion)
   ================================ */

nav.accordion {
  background-color: var(--bg-panel);
  padding: var(--sidebar-padding);
  width: var(--sidebar-width);
  min-height: 100vh;
  position: sticky;
  top: 0;
  overflow-y: auto;
  border-right: 1px solid var(--bg-border);
}

nav.accordion details {
  margin-bottom: 0.8rem;
}

nav.accordion summary {
  cursor: pointer;
  color: var(--accent);
  font-weight: bold;
  padding: 0.6rem 0;
  list-style: none;
}

nav.accordion summary::-webkit-details-marker {
  display: none;
}

nav.accordion details[open] summary {
  color: var(--accent-dark);
}

nav.accordion .panel {
  padding-left: 1rem;
  margin: 0;
  list-style: none;
}

nav.accordion .panel li a {
  display: block;
  padding: 0.3rem 0;
  color: var(--text-main);
  text-decoration: none;
}

nav.accordion .panel li a:hover {
  color: var(--accent);
}

/* ================================
   Main Content
   ================================ */

.layout {
  display: flex;
  align-items: flex-start;
}

main {
  flex: 1;
  padding: var(--content-padding) min(12%, 120px);
}

section {
  margin-bottom: 4rem;
}

.page-title {
  font-size: 2rem;
  color: var(--accent);
  margin-bottom: 2rem;
}

h2 {
  font-size: 1.6rem;
  border-left: 6px solid var(--accent);
  padding-left: 0.6rem;
  margin-bottom: 1.2rem;
}

h3 {
  border-bottom: 1px solid #ccc;
  padding-bottom: 0.3rem;
  margin-top: 2rem;
}

/* --- リスト --- */
ul.publication-list {
  padding-left: 1.2rem;
}

.publication-list li {
  font-size: 1rem;
  line-height: 1.8;
  margin-bottom: 0.8rem;
}

.indent-block {
  padding-left: 2em;
  text-indent: -2em;
  line-height: var(--line-height-main);
}

/* --- リンク --- */
.member-link {
  color: var(--text-main);
  text-decoration: none;
}

.member-link:hover {
  color: var(--accent);
}

/* --- 特殊表記 --- */
.greek {
  font-size: 0.9em;
  letter-spacing: -0.2em;
}

/* --- メディアブロック --- */
.media-block {
  text-align: center;
  margin: 2rem 0;
}

.boids-video {
  width: 100%;
  max-width: 480px;
  display: block;
  margin: 0 auto;
}

.media-block figcaption {
  margin-top: 0.6rem;
  font-size: 0.9rem;
  color: var(--text-light);
}

/* --- PDF バッジ --- */
.pdf-badge {
  display: inline-block;
  background-color: #d9534f;
  color: white;
  font-size: 0.8rem;
  font-weight: bold;
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  margin-right: 0.5rem;
}

/* --- 国旗アイコン --- */
.flag-icon {
  width: 15px;
  height: auto;
  border-radius: 6px;
  vertical-align: middle;
  margin-right: 0.2rem;
}

/* --- 強調ボックス --- */
.example-box {
  border: 1px solid var(--accent);
  background-color: #f0f8f7;
  padding: 1rem 1.2rem;
  margin: 1.5rem 0;
  border-radius: 6px;
}

.example-title {
  color: var(--accent);
  font-weight: bold;
  display: block;
  margin-bottom: 0.4rem;
}

/* --- 小さめ画像 --- */
.image-figure-small {
  width: 45%;
  max-width: 240px;
  height: auto;
  margin: 0 0.5rem;
}

/* --- メンバー紹介 --- */
.member-profile {
  margin-bottom: 2rem;
  line-height: 1.8;
}

/* --- メールアドレス --- */
.mono {
  font-family: "Menlo", "Consolas", monospace;
  font-size: 0.95em;
}

#contact img {
  width: 220px;
  height: auto;
  vertical-align: middle;
  margin-left: 4px;
}

/* --- 上へ戻るボタン --- */
.back-to-top-fixed {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background-color: var(--accent);
  color: white;
  padding: 0.5rem 0.8rem;
  border-radius: 4px;
  font-size: 0.85rem;
  text-decoration: none;
  opacity: 0.8;
}

.back-to-top-fixed:hover {
  opacity: 1;
}

/* --- フッター --- */
footer {
  text-align: center;
  padding: 2rem;
  background-color: var(--bg-panel);
  font-size: 0.9rem;
  color: #666;
  margin-top: 4rem;
}

/* ================================
   Dark Mode
   ================================ */
@media (prefers-color-scheme: dark) {

  body {
    background-color: var(--bg-dark);
    color: var(--text-dark);
  }

  nav.accordion {
    background-color: var(--panel-dark);
    border-right: 1px solid var(--border-dark);
  }

  nav.accordion summary {
    color: #7fd1c8;
  }

  nav.accordion details[open] summary {
    color: #9be3da;
  }

  nav.accordion .panel li a {
    color: var(--text-dark);
  }

  h2 {
    color: var(--text-dark);
  }

  h3 {
    border-bottom-color: #555;
    color: var(--text-dark);
  }

  .publication-list li {
    color: var(--text-dark);
  }

  .media-block figcaption {
    color: #ccc;
  }

  footer {
    background-color: #1a1a1a;
    color: #aaa;
  }
}