:root{
  --bg: #ffffff;
  --text: #0f172a;
  --muted: #475569;
  --primary: #2563eb;
  --card: #f8fafc;
  --border: #e2e8f0;
  --radius: 16px;

  /* fluid type */
  --step--1: clamp(0.85rem, 0.8rem + 0.2vw, 0.95rem);
  --step-0: clamp(1rem, 0.95rem + 0.3vw, 1.1rem);
  --step-1: clamp(1.25rem, 1.15rem + 0.6vw, 1.5rem);
  --step-2: clamp(1.5rem, 1.3rem + 1vw, 2rem);
  --step-3: clamp(2rem, 1.6rem + 1.6vw, 2.6rem);
  --step-4: clamp(2.4rem, 1.9rem + 2.2vw, 3.2rem);
}

@media (prefers-color-scheme: dark){
  :root{
    --bg: #0b1220;
    --text: #e5e7eb;
    --muted: #94a3b8;
    --primary: #60a5fa;
    --card: #0f172a;
    --border: #1f2937;
  }
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }
html{ scroll-behavior: smooth; }
body{
  margin:0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Noto Sans, "Helvetica Neue", Arial, "Apple Color Emoji","Segoe UI Emoji";
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  font-size: var(--step-0);
}

img{ max-width: 100%; display: block; }

.container{
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

.section{ padding: clamp(2.5rem, 2rem + 2vw, 5rem) 0; }
.lead{ font-size: var(--step-1); color: var(--muted); }

.skip-link{
  position:absolute; left:-10000px; top:auto; width:1px; height:1px; overflow:hidden;
}
.skip-link:focus{ left: 1rem; top: 1rem; width:auto; height:auto; background:#fff; color:#000; padding:.5rem 1rem; border-radius: .5rem; }

.site-header{
  position: sticky; top:0; z-index: 10;
  background: color-mix(in oklab, var(--bg) 85%, transparent);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border);
}
.header-inner{
  display:flex; align-items:center; gap:1rem; padding:.75rem 0;
}
.brand{ display:flex; align-items:center; gap:1rem; min-width: 0; }
.site-title{ font-size: var(--step-1); margin:0; line-height:1.2; }
.site-tagline{ margin:.1rem 0 0 0; color: var(--muted); font-size: var(--step--1); }
.avatar{ width:48px; height:48px; object-fit:cover; border-radius: 50%; border:1px solid var(--border); }

.site-nav ul{ display:flex; gap:.75rem; list-style:none; margin:0; padding:0; flex-wrap: wrap; }
.site-nav a{ text-decoration:none; color: var(--muted); padding:.4rem .6rem; border-radius:.6rem; }
.site-nav a:hover{ background: var(--card); color: var(--text); }

.header-actions{ margin-left:auto; }
.btn{
  font: inherit;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  padding: .5rem .9rem;
  border-radius: .7rem;
  cursor: pointer;
}
.btn:hover{ filter: brightness(1.02); }
.btn.primary{
  background: var(--primary);
  color: white;
  border-color: transparent;
}

.hero{
  padding: clamp(3rem, 4vw + 2rem, 6rem) 0;
  border-bottom: 1px solid var(--border);
}
.hero h2{ font-size: var(--step-3); margin: 0 0 .5rem 0; }
.hero .lead{ max-width: 55ch; }

.two-col{
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: clamp(1rem, 2vw, 2rem);
}
@media (max-width: 900px){
  .two-col{ grid-template-columns: 1fr; }
}

.badges{ display:flex; gap:.5rem; flex-wrap: wrap; padding:0; margin:1rem 0 0 0; list-style:none;}
.badges li{
  border:1px solid var(--border); background: var(--card);
  padding:.35rem .6rem; border-radius:999px; font-size: var(--step--1);
}

.card{
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(1rem, 1rem + .5vw, 1.25rem);
}
.cards.grid{
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
}

/* クリックできる研究カード */
.research-card{
  text-align: left;
  cursor: pointer;
  transition: transform .08s ease, box-shadow .2s ease;
}
.research-card .more{
  display:inline-block;
  margin-top:.25rem;
  font-size: var(--step--1);
  color: var(--primary);
}
.research-card:hover{
  transform: translateY(-1px);
  box-shadow: 0 6px 20px color-mix(in oklab, var(--text) 10%, transparent);
}

.meta dl{ display:grid; grid-template-columns: 7rem 1fr; gap:.4rem .8rem; margin:0; }
.meta dt{ color: var(--muted); }
.meta dd{ margin:0; }

.pub-list{
  display: grid;
  gap: 1rem;
}
.pub-year{
  margin: 2rem 0 0.5rem 0;
  font-size: var(--step-1);
  border-bottom: 1px dashed var(--border);
  padding-bottom: .25rem;
}
.pub-item{
  display: grid;
  gap: .2rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: .9rem 1rem;
}
.pub-title{ font-weight: 600; }
.pub-authors, .pub-venue{ color: var(--muted); }
.pub-links a{ margin-right: .8rem; }

.site-footer{
  border-top: 1px solid var(--border);
  padding: 1rem 0;
}
.footer-inner{ display:flex; justify-content:space-between; align-items:center; gap:.5rem; flex-wrap: wrap; }
#lastUpdated{ color: var(--muted); }

/* a11y focus */
a, button{ outline-offset: 3px; }

/* ---- フィルタ & ページャ（他ページ共通） ---- */
.filters { display: block; }
.filters-row{
  display: grid;
  grid-template-columns: repeat(3, minmax(160px, 1fr));
  gap: .75rem;
}
.filters label{ display:flex; flex-direction: column; gap:.3rem; font-size: var(--step--1); color: var(--muted); }
.filters select, .filters input[type="search"]{
  font: inherit; padding:.55rem .65rem; border:1px solid var(--border); border-radius:.6rem; background: var(--bg); color: var(--text);
}
.grow{ grid-column: span 1; }
@media (max-width: 720px){
  .filters-row{ grid-template-columns: 1fr; }
  .grow{ grid-column: auto; }
}

.pagination{
  display:flex; align-items:center; gap:.75rem; justify-content:center; margin-top: 1rem;
}
.page-info{ color: var(--muted); }

.muted{ color: var(--muted); margin-top: .5rem; }
.site-title-link{ color: inherit; text-decoration: none; }

/* ---- dialog（モーダル） ---- */
dialog{
  border: none;
  padding: 0;
  width: min(720px, 92vw);
  background: transparent;
}
dialog::backdrop{
  background: color-mix(in oklab, black 40%, transparent);
  backdrop-filter: blur(2px);
}
.dialog-inner{
  margin: 0;
}
.dialog-header{
  display:flex; justify-content:space-between; align-items:center; gap:.5rem;
  margin-bottom: .5rem;
}
.dialog-header h4{ margin:0; font-size: var(--step-1); }
.dialog-close{
  line-height: 1;
  font-size: var(--step-1);
}
.dialog-body{ display:grid; gap:.5rem; }
.dialog-body ul{ margin: .25rem 0 0 1rem; }
.dialog-footer{
  display:flex; justify-content:flex-end; gap:.5rem; margin-top: 1rem;
}

/* ---- 追加: ソーシャルアイコン ---- */
.socials{
  display:flex;
  align-items:center;
  gap:.5rem;
}
.social{
  display:inline-flex;
  width: 32px;
  height: 32px;
  border: 1px solid var(--border);
  border-radius: 8px;
  align-items:center;
  justify-content:center;
  background: var(--card);
  color: var(--text);
  text-decoration: none;
  transition: transform .08s ease, filter .15s ease, background .2s ease;
}
.social:hover{
  transform: translateY(-1px);
  filter: brightness(1.03);
}
.social:active{
  transform: translateY(0);
}
.social svg{
  width: 18px;
  height: 18px;
  fill: currentColor;
}