/* ===========================
   日本情報経営学会 第91回全国大会
   共通スタイルシート（高齢読者向け・高可読性版）
   =========================== */

:root {
  /* ブラウザやOSのダークモードで自動反転されないよう、明示的に明色指定とする */
  color-scheme: light;

  --primary: #002b5c;        /* 学会基調色：濃紺（コントラスト強め） */
  --primary-dark: #001a3d;
  --accent: #b00020;         /* アクセント：濃い赤 */
  --bg: #ffffff;
  --bg-soft: #eef2f7;
  --text: #111111;           /* 本文：ほぼ黒 */
  --text-strong: #000000;
  --border: #b0b8c4;
  --link: #0033a0;           /* リンク：濃い青 */
  --link-hover: #b00020;
  --max-width: 1100px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 18px;           /* ブラウザのデフォルト16pxより大きく */
}

html { background: #ffffff; }
body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", "MS PGothic",
               -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 1.15rem;        /* 約 20.7px */
  line-height: 1.95;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--link);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 600;
}
a:hover {
  color: var(--link-hover);
}

p {
  margin: 0.6em 0 1em;
}

ul, ol {
  margin: 0.6em 0 1em;
  padding-left: 1.6em;
}
li {
  margin-bottom: 0.4em;
}

/* ---------- ヘッダー ---------- */
.site-header {
  background: var(--primary);
  color: #fff;
  border-bottom: 6px solid var(--accent);
}
.site-header__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 22px 28px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.site-title {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 500;
  line-height: 1.5;
  color: #fff;
}
.site-title a {
  color: #fff;
  text-decoration: none;
  font-weight: 500;
}
.site-title strong {
  display: block;
  font-size: 1.8rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  margin-top: 4px;
}
.site-header__date {
  font-size: 1.15rem;
  font-weight: 700;
  background: rgba(255,255,255,0.12);
  padding: 8px 16px;
  border-radius: 4px;
}

/* ---------- ナビゲーション ---------- */
.global-nav {
  background: var(--primary-dark);
}
.global-nav__inner {
  max-width: var(--max-width);
  margin: 0 auto;
}
.global-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
}
.global-nav li {
  flex: 1 1 auto;
  text-align: center;
  margin: 0;
}
.global-nav a {
  display: block;
  padding: 18px 16px;
  color: #fff;
  font-size: 1.1rem;
  font-weight: 700;
  text-decoration: none;
  border-right: 1px solid rgba(255,255,255,0.15);
  transition: background 0.15s;
}
.global-nav li:last-child a {
  border-right: none;
}
.global-nav a:hover,
.global-nav a.is-current {
  background: var(--accent);
  color: #fff;
}

/* ---------- ヒーロー（トップページ） ---------- */
.hero {
  background: #002b5c;       /* グラデーション廃止、単色で読みやすく */
  color: #fff;
  padding: 72px 28px;
  text-align: center;
}
.hero__edition {
  display: inline-block;
  padding: 6px 18px;
  margin-bottom: 22px;
  border: 2px solid #fff;
  border-radius: 999px;
  font-size: 1rem;
  letter-spacing: 0.15em;
  font-weight: 700;
}
.hero__title {
  margin: 0 0 18px;
  font-size: 2.6rem;         /* 大きく */
  font-weight: 800;
  line-height: 1.4;
}
.hero__theme {
  margin: 28px auto 30px;
  padding: 22px 28px;
  max-width: 800px;
  background: #ffffff;       /* 不透明：地の文字を読みやすく */
  color: var(--text-strong);
  border-left: 8px solid var(--accent);
  text-align: left;
}
.hero__theme strong {
  display: block;
  font-size: 1.4rem;
  line-height: 1.6;
  color: var(--primary);
}
.hero__theme small {
  display: block;
  font-size: 0.95rem;
  color: #444;
  margin-top: 10px;
}
.hero__meta {
  font-size: 1.4rem;
  font-weight: 700;
  margin-top: 18px;
  line-height: 1.8;
}
.hero__meta span {
  display: inline-block;
  margin: 4px 14px;
}

/* ---------- メイン本文 ---------- */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 56px 28px 72px;
}

.page-title {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--primary);
  border-bottom: 4px solid var(--primary);
  padding-bottom: 12px;
  margin-top: 0;
  margin-bottom: 36px;
  line-height: 1.4;
}

.section {
  margin-bottom: 56px;
}
.section__title {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--primary);
  border-left: 8px solid var(--accent);
  padding-left: 16px;
  margin-top: 0;
  margin-bottom: 22px;
  line-height: 1.5;
}
.section__subtitle {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary);
  margin: 32px 0 12px;
  line-height: 1.5;
}

/* ---------- 表 ---------- */
.info-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 20px;
  font-size: 1.1rem;
}
.info-table th,
.info-table td {
  border: 2px solid var(--border);
  padding: 16px 20px;
  text-align: left;
  vertical-align: top;
  line-height: 1.8;
}
.info-table th {
  background: var(--bg-soft);
  width: 210px;
  font-weight: 700;
  color: var(--primary);
}

/* ---------- カード ---------- */
.card {
  border: 2px solid var(--border);
  border-radius: 6px;
  padding: 26px 30px;
  background: #fff;
  margin-bottom: 22px;
}
.card__label {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 3px;
  margin-bottom: 12px;
  letter-spacing: 0.08em;
}
.card__title {
  font-size: 1.5rem;
  font-weight: 800;
  margin: 6px 0 6px;
  color: var(--primary);
  line-height: 1.5;
}
.card__affiliation {
  color: #222;              /* グレーをやめて濃く */
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 10px;
}

/* ---------- バッジ ---------- */
.badge {
  display: inline-block;
  padding: 4px 14px;
  font-size: 0.95rem;
  border-radius: 3px;
  font-weight: 700;
  vertical-align: middle;
}
.badge--coming {
  background: #fff2a8;
  color: #5a4500;
  border: 1px solid #c9b800;
}
.badge--open {
  background: #cfecd2;
  color: #144a1d;
  border: 1px solid #4a8a55;
}

/* ---------- 重要日程リスト ---------- */
.schedule-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.schedule-list li {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  padding: 16px 0;
  border-bottom: 2px dashed var(--border);
  font-size: 1.1rem;
  margin: 0;
}
.schedule-list__date {
  flex: 0 0 220px;
  color: var(--primary);
  font-weight: 700;
}
.schedule-list__item {
  flex: 1;
  color: var(--text-strong);
}

/* ---------- お知らせリスト ---------- */
.news-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.news-list li {
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  font-size: 1.1rem;
  margin: 0;
}
.news-list time {
  display: inline-block;
  width: 130px;
  color: var(--primary);
  font-weight: 700;
  font-size: 1.05rem;
}

/* ---------- 注意ボックス ---------- */
.note {
  background: var(--bg-soft);
  border-left: 6px solid var(--primary);
  padding: 18px 22px;
  margin: 20px 0;
  font-size: 1.1rem;
  line-height: 1.85;
  color: var(--text-strong);
}
.note--accent {
  border-left-color: var(--accent);
  background: #fff5f5;
}

/* ---------- ボタン ---------- */
.btn {
  display: inline-block;
  background: var(--primary);
  color: #fff !important;
  padding: 14px 32px;
  border-radius: 4px;
  text-decoration: none !important;
  font-weight: 700;
  font-size: 1.15rem;
  border: none;
  cursor: pointer;
}
.btn:hover {
  background: var(--accent);
}
.btn--disabled {
  background: #888;
  cursor: not-allowed;
  pointer-events: none;
}

/* ---------- フッター ---------- */
.site-footer {
  background: var(--primary-dark);
  color: #ffffff;
  padding: 36px 28px 24px;
  margin-top: 56px;
  font-size: 1.05rem;
  line-height: 1.8;
}
.site-footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
}
.site-footer p {
  margin: 6px 0;
}
.site-footer a {
  color: #ffffff;
}
.copyright {
  text-align: center;
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid rgba(255,255,255,0.25);
  font-size: 0.95rem;
  color: #d8def0;
}

/* ---------- レスポンシブ ---------- */
@media (max-width: 720px) {
  html { font-size: 17px; }
  .site-title strong { font-size: 1.45rem; }
  .global-nav ul { flex-direction: column; }
  .global-nav a {
    border-right: none;
    border-bottom: 1px solid rgba(255,255,255,0.18);
    padding: 16px;
    font-size: 1.05rem;
  }
  .hero { padding: 48px 18px; }
  .hero__title { font-size: 1.9rem; }
  .hero__theme strong { font-size: 1.2rem; }
  .hero__meta { font-size: 1.15rem; }
  .page-title { font-size: 1.7rem; }
  .section__title { font-size: 1.3rem; }
  .info-table th { width: 120px; font-size: 1rem; padding: 12px 14px; }
  .info-table td { padding: 12px 14px; font-size: 1rem; }
  .schedule-list li { flex-direction: column; gap: 4px; }
  .schedule-list__date { flex: none; }
}

/* ---------- ヒーロー内リンク ---------- */
.hero__meta a {
  color: #fff;
  text-decoration: underline;
  text-underline-offset: 5px;
  text-decoration-thickness: 2px;
}
.hero__meta a:hover {
  opacity: 0.8;
}

/* ---------- 地図埋め込み（レスポンシブ） ---------- */
.map-embed {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  margin: 18px 0 10px;
  border: 1px solid #ccc;
}
.map-embed iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* ---------- モバイル用ハンバーガーメニュー ---------- */
.nav-toggle {
  display: none;
  width: 100%;
  box-sizing: border-box;
  align-items: center;
  gap: 12px;
  padding: 16px 18px;
  background: transparent;
  border: 0;
  border-bottom: 1px solid rgba(255,255,255,0.18);
  color: #fff;
  font-family: inherit;
  font-size: 1.05rem;
  font-weight: 700;
  cursor: pointer;
  text-align: left;
}
.nav-toggle__icon {
  position: relative;
  flex: none;
  width: 22px;
  height: 16px;
}
.nav-toggle__icon span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: #fff;
  transition: transform 0.2s, opacity 0.2s;
}
.nav-toggle__icon span:nth-child(1) { top: 0; }
.nav-toggle__icon span:nth-child(2) { top: 7px; }
.nav-toggle__icon span:nth-child(3) { top: 14px; }
.nav-toggle.is-open .nav-toggle__icon span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open .nav-toggle__icon span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open .nav-toggle__icon span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 720px) {
  .nav-toggle { display: flex; }
  .global-nav ul {
    display: none;
  }
  .global-nav ul.is-open {
    display: block;
  }
}

/* ---------- 締切カウントダウン ---------- */
.countdown {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 22px 0;
  padding: 20px 26px;
  background: var(--bg-soft);
  border: 2px solid var(--primary);
  border-left: 10px solid var(--accent);
  border-radius: 4px;
}
.countdown__label {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary);
}
.countdown__value {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1.2;
}
.countdown__value .countdown__num {
  font-size: 2.8rem;
  margin: 0 4px;
  letter-spacing: 0.02em;
}
.countdown__date {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-strong);
}
.countdown.is-urgent {
  background: #fdecef;
}
.countdown.is-closed {
  border-left-color: var(--border);
  background: #f2f2f2;
}
.countdown.is-closed .countdown__value {
  color: var(--text);
  font-size: 1.3rem;
}

@media (max-width: 720px) {
  .countdown {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    padding: 16px 18px;
  }
  .countdown__value .countdown__num { font-size: 2.3rem; }
}