:root {
  --navy: #0552c9;
  --navy-2: #0b3d91;
  --gold: #0366d6;
  --gold-light: #d7e6ff;
  --cream: #fafbfd;
  --paper: #ffffff;
  --ink: #1b1f27;
  --sub: #656b78;
  --line: #e5e9f0;
  --shadow: 0 1px 2px rgba(10,25,48,0.04), 0 12px 32px rgba(10,25,48,0.06);
  --shadow-lg: 0 20px 60px rgba(10,25,48,0.14);
  --radius: 20px;
  --bg-glow-1: rgba(0,70,173,0.32);
  --bg-glow-2: rgba(0,90,190,0.20);
  --bg-glow-3: rgba(214,32,52,0.28);
  --tricolor-red: #d62034;
  color-scheme: light;
}

[data-theme="dark"] {
  --navy: #7db0ff;
  --navy-2: #a9c8ff;
  --gold: #7db0ff;
  --gold-light: #1c2c46;
  --cream: #0f1420;
  --paper: #171d2b;
  --ink: #e6e9f0;
  --sub: #9aa3b5;
  --line: #262d3d;
  --shadow: 0 1px 2px rgba(0,0,0,0.3), 0 12px 32px rgba(0,0,0,0.35);
  --shadow-lg: 0 20px 60px rgba(0,0,0,0.5);
  --bg-glow-1: rgba(125,176,255,0.16);
  --bg-glow-2: rgba(125,176,255,0.12);
  --bg-glow-3: rgba(255,90,100,0.07);
  --tricolor-red: #ff5a64;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Inter", "Hiragino Sans", "Noto Sans JP", sans-serif;
  background-color: var(--cream);
  background-image:
    radial-gradient(1000px 700px at 0% 12%, var(--bg-glow-1), transparent 65%),
    radial-gradient(1000px 700px at 100% 12%, var(--bg-glow-3), transparent 65%),
    radial-gradient(1000px 700px at 0% 50%, var(--bg-glow-1), transparent 65%),
    radial-gradient(1000px 700px at 100% 50%, var(--bg-glow-3), transparent 65%),
    radial-gradient(1000px 700px at 0% 88%, var(--bg-glow-1), transparent 65%),
    radial-gradient(1000px 700px at 100% 88%, var(--bg-glow-3), transparent 65%);
  background-repeat: no-repeat;
  background-size: 100% 100%;
  background-attachment: scroll;
  color: var(--ink);
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s, color 0.3s;
}

.serif { font-family: "Fraunces", "Noto Serif JP", serif; }

a { color: var(--navy); }

/* ---------- noise / texture ---------- */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 999;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- top progress bar ---------- */
#progress {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--navy) 0%, var(--navy) 33%, #ffffff 33%, #ffffff 66%, var(--tricolor-red) 66%, var(--tricolor-red) 100%);
  z-index: 1000;
  transition: width 0.1s linear;
}

/* ---------- hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background: #0a1930;
  color: #fff;
  padding: 120px 24px 100px;
  text-align: center;
}

.hero.hero--compact {
  padding: 76px 24px 56px;
}

.hero .bg-photo {
  position: absolute;
  inset: 0;
  background-image: url("hero-bg.jpg");
  background-size: cover;
  background-position: center 30%;
}

.hero .bg-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(6,14,32,0.72) 0%, rgba(6,14,32,0.55) 45%, rgba(6,14,32,0.88) 100%);
}

.hero-inner { position: relative; z-index: 2; max-width: 760px; margin: 0 auto; }

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.72em;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold-light);
  border: 1px solid rgba(233,217,168,0.35);
  padding: 8px 18px;
  border-radius: 999px;
  margin-bottom: 34px;
  background: rgba(255,255,255,0.03);
  text-decoration: none;
}
.kicker::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(184,145,47,0.25);
}

.hero h1 {
  margin: 0;
  font-weight: 600;
  font-size: clamp(2.4em, 6vw, 4.1em);
  letter-spacing: -0.01em;
  line-height: 1.15;
}
.hero.hero--compact h1 { font-size: clamp(1.8em, 4.5vw, 2.6em); }

.hero h1 .en {
  display: block;
  font-family: "Inter", sans-serif;
  font-weight: 400;
  font-size: 0.32em;
  letter-spacing: 0.04em;
  color: rgba(255,255,255,0.55);
  margin-top: 18px;
  text-transform: uppercase;
}

.hero .role {
  margin: 28px 0 0;
  font-size: 1.15em;
  color: rgba(255,255,255,0.82);
  font-weight: 500;
}

/* ---------- nav ---------- */
nav.subnav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2px;
  flex-wrap: wrap;
  background: rgba(250, 251, 253, 0.82);
  backdrop-filter: blur(14px) saturate(1.4);
  -webkit-backdrop-filter: blur(14px) saturate(1.4);
  border-bottom: 1px solid var(--line);
  padding: 14px 16px;
}
[data-theme="dark"] nav.subnav { background: rgba(15,20,32,0.82); }
nav.subnav a {
  text-decoration: none;
  color: var(--sub);
  font-weight: 600;
  font-size: 0.86em;
  padding: 9px 18px;
  border-radius: 999px;
  transition: all 0.2s;
  position: relative;
}
nav.subnav a:hover { color: var(--navy); background: var(--paper); }
nav.subnav a.active { color: var(--navy); background: var(--paper); box-shadow: var(--shadow); }
nav.subnav a.active::after {
  content: "";
  position: absolute;
  left: 50%; bottom: 4px;
  transform: translateX(-50%);
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--gold);
}

#themeToggle {
  margin-left: 8px;
  width: 38px; height: 38px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--navy);
  font-size: 1em;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: transform 0.25s, box-shadow 0.2s;
  flex-shrink: 0;
}
#themeToggle:hover { box-shadow: var(--shadow); transform: rotate(14deg); }

/* ---------- main layout ---------- */
main { max-width: 860px; margin: 0 auto; padding: 0 24px; }

section {
  padding: 84px 0;
  border-bottom: 1px solid var(--line);
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
  scroll-margin-top: 90px;
}
section.in-view { opacity: 1; transform: translateY(0); }
section:last-of-type { border-bottom: none; }

.eyebrow {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 0.76em;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--sub);
  font-weight: 700;
  margin-bottom: 18px;
}
.eyebrow::after { content: ""; flex: 1; height: 1px; background: var(--line); }

h2 {
  font-family: "Fraunces", serif;
  font-weight: 600;
  font-size: 2.1em;
  color: var(--navy);
  margin: 0 0 44px;
  letter-spacing: -0.01em;
}

h3 {
  font-size: 1em;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--ink);
  font-weight: 700;
  margin: 44px 0 20px;
  padding-left: 12px;
  border-left: 3px solid var(--gold);
}
h3:first-of-type { margin-top: 0; }

h4.sub-heading {
  font-family: "Fraunces", serif;
  font-size: 1.05em;
  font-weight: 600;
  color: var(--navy);
  margin: 28px 0 14px;
}

.figure {
  margin: 28px 0;
  padding: 24px 20px 20px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  text-align: center;
}
.figure svg { width: 100%; max-width: 440px; height: auto; }
.figure-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.figure-scroll svg { min-width: 600px; }
.figure figcaption {
  margin-top: 12px;
  font-size: 0.82em;
  color: var(--sub);
  line-height: 1.6;
}

p { color: var(--ink); }

/* profile badges */
.badge-row { display: flex; flex-wrap: wrap; gap: 10px; }
.badge {
  font-size: 0.85em;
  font-weight: 600;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 8px 16px;
  border-radius: 999px;
  box-shadow: var(--shadow);
}

/* timeline (career) */
.timeline { position: relative; padding-left: 28px; }
.timeline::before {
  content: "";
  position: absolute;
  left: 5px; top: 6px; bottom: 6px;
  width: 1px;
  background: var(--line);
}
.timeline-item { position: relative; padding-bottom: 26px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -28px; top: 6px;
  width: 11px; height: 11px;
  border-radius: 50%;
  background: var(--cream);
  border: 2px solid var(--gold);
}
.timeline-item .when {
  font-size: 0.8em;
  font-weight: 700;
  color: var(--sub);
  letter-spacing: 0.03em;
}
.timeline-item .what { margin-top: 4px; color: var(--ink); }

/* research intro card */
.lead-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px 36px;
  box-shadow: var(--shadow);
}

/* small applications callout (inline, not a standalone section) */
.applet-box {
  margin-top: 20px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
  border-radius: 14px;
  padding: 22px 26px;
  box-shadow: var(--shadow);
}
.applet-box .applet-title {
  font-weight: 700;
  font-size: 0.92em;
  color: var(--ink);
  margin-bottom: 10px;
}
.applet-box ul {
  margin: 0;
  padding-left: 20px;
}
.applet-box li {
  font-size: 0.92em;
  color: var(--sub);
  margin-bottom: 8px;
}
.applet-box li:last-child { margin-bottom: 0; }
.applet-box li b { color: var(--ink); }

/* publication filters */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 36px;
}
.filters button {
  font-family: inherit;
  font-size: 0.82em;
  font-weight: 600;
  color: var(--sub);
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 9px 18px;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.2s;
}
.filters button:hover { color: var(--navy); border-color: var(--navy); }
.filters button.active {
  color: #fff;
  background: var(--navy);
  border-color: var(--navy);
}

.pub-search {
  width: 100%;
  font-family: inherit;
  font-size: 0.92em;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px 16px;
  margin-bottom: 10px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.pub-search:focus { border-color: var(--navy); box-shadow: 0 0 0 3px var(--gold-light); }

.pub-count {
  font-size: 0.8em;
  color: var(--sub);
  margin: 0 0 26px;
}

ol.pub-list { list-style: none; margin: 0; padding: 0; counter-reset: pub; }
ol.pub-list li {
  counter-increment: pub;
  position: relative;
  padding: 22px 0 22px 56px;
  border-bottom: 1px solid var(--line);
  font-size: 0.96em;
  color: var(--ink);
  transition: opacity 0.25s, transform 0.25s, max-height 0.25s;
}
ol.pub-list li:last-child { border-bottom: none; }
ol.pub-list li::before {
  content: counter(pub);
  position: absolute;
  left: 0; top: 20px;
  width: 34px; height: 34px;
  border-radius: 10px;
  background: var(--navy);
  color: var(--gold-light);
  font-family: "Fraunces", serif;
  font-weight: 600;
  font-size: 0.88em;
  display: flex;
  align-items: center;
  justify-content: center;
}
ol.pub-list li.hide { display: none; }
ol.pub-list li .venue { color: var(--ink); font-weight: 600; font-style: italic; }
ol.pub-list[data-group="talk"]:not(.expanded) li:nth-child(n+6) { display: none; }

.show-more-btn {
  display: block;
  margin: 8px auto 0;
  font-family: inherit;
  font-size: 0.85em;
  font-weight: 600;
  color: var(--navy);
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 10px 24px;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.2s;
}
.show-more-btn:hover { background: var(--navy); color: #fff; border-color: var(--navy); }

/* two-col card grid */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
@media (max-width: 640px) {
  :root {
    --bg-glow-1: rgba(0,70,173,0.28);
    --bg-glow-3: rgba(214,32,52,0.24);
  }
}

@media (max-width: 640px) { .grid-2 { grid-template-columns: 1fr; } }

.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 24px 26px;
  box-shadow: var(--shadow);
  transition: transform 0.25s, box-shadow 0.25s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.card .tag {
  font-size: 0.72em;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--sub);
  font-weight: 700;
}
.card .title { margin-top: 8px; font-weight: 600; color: var(--ink); }
.card p.desc { margin: 10px 0 0; font-size: 0.92em; color: var(--sub); }

.grants-list, .awards-list, .society-list { list-style: none; margin: 0; padding: 0; }
.grants-list li {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 22px 26px;
  margin-bottom: 14px;
  box-shadow: var(--shadow);
}
.grants-list li:last-child { margin-bottom: 0; }
.grants-list .g-title { font-weight: 600; color: var(--ink); }
.grants-list .g-meta { margin-top: 6px; font-size: 0.86em; color: var(--sub); }

.awards-list li, .society-list li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px dashed var(--line);
}
.awards-list li:last-child, .society-list li:last-child { border-bottom: none; }
.awards-list .year {
  font-family: "Fraunces", serif;
  font-weight: 600;
  color: var(--sub);
  min-width: 52px;
}
.society-list li::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--gold);
  flex-shrink: 0;
}

/* contact */
#contact {
  text-align: center;
  background: radial-gradient(900px 400px at 50% -20%, #1a3766 0%, var(--navy) 60%, #071223 100%);
  color: #fff;
  border-radius: var(--radius);
  padding: 80px 32px;
  margin: 40px 0 80px;
  border: none;
}
#contact .eyebrow { color: var(--gold-light); justify-content: center; }
#contact .eyebrow::after { display: none; }
#contact h2 { color: #fff; }
#contact p { color: rgba(255,255,255,0.82); }
#contact small { color: rgba(255,255,255,0.5); }

.email-pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 18px;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.18);
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 600;
  color: #fff;
  cursor: pointer;
  transition: background 0.2s;
}
.email-pill:hover { background: rgba(255,255,255,0.16); }

footer {
  text-align: center;
  font-size: 0.82em;
  color: var(--sub);
  padding: 32px 0 60px;
}

/* back to top */
#toTop {
  position: fixed;
  right: 22px; bottom: 22px;
  width: 46px; height: 46px;
  border-radius: 50%;
  background: var(--navy);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity 0.25s, transform 0.25s;
  z-index: 200;
  border: none;
}
#toTop.show { opacity: 1; pointer-events: auto; transform: translateY(0); }