/* research ページ共通のスタイル。配色・書体・ヘッダーは web-sendaicmc に揃え、背景画像は使わない */
:root {
  --ink: #333537;
  /* Charcoal mixed into white: 15% and 25%. */
  --menu-bg: #e0e1e1;
  --menu-hover: #cccdcd;
  --ink-soft: #5c5f62;
  --paper: #fff;
  --line: rgba(51, 53, 55, 0.28);
  --font-ja: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Noto Sans JP", sans-serif;
  --font-en: "Avenir Next", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --header-h: 76px;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100svh;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-en), var(--font-ja);
  font-size: 15px;
  line-height: 1.9;
  letter-spacing: 0.04em;
}

a { color: inherit; text-underline-offset: 3px; }

/* ---------- header ---------- */

.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 10;
  height: var(--header-h);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0 32px;
}

/* 白は、ヘッダーより下まで延ばしてから透明へ消える */
.site-header::before {
  content: "";
  position: absolute;
  inset: 0 0 -48px 0;
  z-index: -1;
  pointer-events: none;
  background: linear-gradient(to bottom, rgba(255, 255, 255, 0.92) 0%, rgba(255, 255, 255, 0.8) 50%, rgba(255, 255, 255, 0) 100%);
}

.site-nav ul { display: flex; gap: 34px; margin: 0; padding: 0; list-style: none; }

.site-nav a {
  display: inline-block;
  padding: 6px 0;
  font-size: 13px;
  letter-spacing: 0.14em;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

.site-nav a:hover,
.site-nav a[aria-current] { border-bottom-color: var(--ink); }

/* 言語の切り替え。sendaicmc の X ボタンの位置（右端） */
.lang-switch {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  letter-spacing: 0.14em;
}

.lang-switch a { text-decoration: none; color: var(--ink-soft); }
.lang-switch a:hover, .lang-switch a:focus-visible { color: var(--ink); }
.lang-switch .is-current { font-weight: 700; }
.lang-sep { color: var(--ink-soft); }

/* ---------- page ---------- */

.page {
  flex: 1;
  width: min(820px, calc(100% - 48px));
  margin: 0 auto;
  padding: calc(var(--header-h) + 56px) 0 72px;
}

.block + .block {
  margin-top: 40px;
  padding-top: 40px;
  border-top: 1px solid var(--line);
}

.block-head + .block { margin-top: 0; padding-top: 0; border-top: 0; }

.block h1,
.block h2 {
  margin: 0 0 18px;
  font-size: 26px;
  font-weight: 400;
  letter-spacing: 0.2em;
  line-height: 1.4;
}

.block p { margin: 0 0 1em; }
.block p:last-child { margin-bottom: 0; }
.who { font-size: 17px; }

/* 名前の上に、本文8行分（8 × 行間1.9 × 15px）の正方形の写真 */
.profile { display: flex; flex-direction: column; align-items: flex-start; gap: 20px; }
.portrait { width: 228px; height: 228px; object-fit: cover; display: block; }

.plain { margin: 0; padding: 0; list-style: none; }

.timeline { width: 100%; border-collapse: collapse; font-size: 14.5px; line-height: 1.7; }
.timeline td { padding: 6px 16px 6px 0; vertical-align: top; text-align: left; }
.timeline td:first-child { width: 15em; white-space: nowrap; letter-spacing: 0.06em; }

.pubs td.year { width: 4em; }
.pubs td.entry { width: auto; white-space: normal; letter-spacing: inherit; font-size: inherit; color: inherit; }
.pubs .me { text-decoration: underline; text-underline-offset: 3px; }
.pubs .item { display: grid; grid-template-columns: 2em 1fr; }
.pubs .no { color: var(--ink-soft); }
.pubs .venue { color: var(--ink-soft); }

.note { margin-top: 12px; font-size: 14.5px; color: var(--ink-soft); }

.site-footer {
  padding: 20px 32px 28px;
  text-align: center;
  font-size: 11px;
  letter-spacing: 0.18em;
  border-top: 1px solid var(--line);
}

.site-footer a {
  color: inherit;
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

/* ---------- narrow screens ---------- */

@media (max-width: 760px) {
  .site-header { padding: 0 20px; }
  .site-nav a { font-size: 12px; letter-spacing: 0.1em; }
  .page { padding-top: calc(var(--header-h) + 32px); }
  .block h1, .block h2 { font-size: 22px; }
  .portrait { width: 152px; height: 152px; }
  /* 表は2列を縦に積み、期間をタイトルの上に小さく出す */
  .timeline tr { display: block; padding: 6px 0; }
  .timeline td { display: block; padding: 0; }
  .timeline td:first-child { width: auto; font-size: 12.5px; color: var(--ink-soft); }
  .pubs td.year { width: auto; }
  .pubs td.entry { font-size: 14.5px; color: var(--ink); }
}

html { scroll-padding-top: 100px; }

/* Section dropdowns shared with the Development site. */
.site-nav .section-item { position: relative; }
.site-nav .section-item:has(.section-menu[open]) > a { border-bottom-color: var(--ink); }
.site-nav .section-item:has(.section-menu[open])::after { content: ""; position: absolute; top: 100%; left: 0; right: 0; height: 8px; }
.section-menu > summary { display: none; cursor: pointer; font-size: 11px; }
.site-nav .section-dropdown { position: absolute; top: 100%; left: 50%; transform: translateX(-50%); display: block; width: max-content; min-width: 180px; max-width: min(300px, calc(100vw - 40px)); max-height: calc(100svh - 100px); overflow-y: auto; margin: 8px 0 0; padding: 0; list-style: none; background: var(--menu-bg); border: 0; }
.site-nav .section-dropdown li + li { border-top: 1px solid #fff; }
.site-nav .section-dropdown a { display: block; padding: 12px 20px; border: 0; color: var(--ink); text-decoration: none; }
.site-nav .section-dropdown a:hover, .site-nav .section-dropdown a:focus-visible { background: var(--menu-hover); text-decoration: none; }
@media (hover: none) {
  .section-menu > summary { display: block; padding: 4px 0; }
}

@media (max-width: 760px) {
  .site-nav .section-item:has(.section-menu[open])::after { position: fixed; top: calc(var(--header-h) - 20px); left: 20px; right: 20px; height: 28px; }
  .site-nav .section-dropdown { position: fixed; top: 76px; left: 20px; right: 20px; transform: none; width: auto; max-width: none; }
}

/* Narrow layouts keep only direct parent links. */
@media (max-width: 1200px) {
  .site-nav .section-menu { display: none; }
}