/* ===== Tokens ===== */
:root {
  --bg: #ffffff;
  --bg-soft: #f6f7f9;
  --bg-elev: #ffffff;
  --text: #1a1c1f;
  --text-soft: #565b62;
  --text-faint: #8a9099;
  --line: #e7e9ec;
  --accent: #2f6f6a;
  --accent-soft: #e6f0ef;
  --hot: #b9542b;
  --hot-soft: #fbeee6;
  --shadow: 0 1px 2px rgba(16,24,40,.04), 0 8px 24px rgba(16,24,40,.06);
  --maxw: 1080px;
  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}
[data-theme="dark"] {
  --bg: #0f1214;
  --bg-soft: #15191c;
  --bg-elev: #171c1f;
  --text: #e8eaed;
  --text-soft: #a7adb4;
  --text-faint: #6f767d;
  --line: #262c30;
  --accent: #5fb3ab;
  --accent-soft: #16332f;
  --hot: #e08a5f;
  --hot-soft: #2c1f17;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.35);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; }
body {
  margin: 0;
  font-family: var(--sans);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background .3s ease, color .3s ease;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { line-height: 1.2; margin: 0; }

/* ===== Nav ===== */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav__inner {
  max-width: var(--maxw); margin: 0 auto; padding: 0 24px;
  height: 60px; display: flex; align-items: center; gap: 20px;
}
.nav__brand { font-family: var(--serif); font-weight: 600; font-size: 1.15rem; color: var(--text); }
.nav__brand:hover { text-decoration: none; }
.nav__links { margin-left: auto; display: flex; gap: 22px; }
.nav__links a { color: var(--text-soft); font-size: .92rem; font-weight: 500; }
.nav__links a:hover { color: var(--accent); text-decoration: none; }
.theme-toggle {
  border: 1px solid var(--line); background: var(--bg-elev); color: var(--text-soft);
  width: 38px; height: 38px; border-radius: 10px; cursor: pointer; font-size: 1.1rem;
  display: grid; place-items: center; transition: all .2s ease;
}
.theme-toggle:hover { color: var(--accent); border-color: var(--accent); }

/* ===== Hero ===== */
.hero {
  max-width: var(--maxw); margin: 0 auto; padding: 72px 24px 48px;
  display: grid; grid-template-columns: 200px 1fr; gap: 56px; align-items: center;
}
.hero__photo img {
  width: 100%; max-width: 200px; border-radius: 10px; box-shadow: var(--shadow);
  border: 1px solid var(--line); display: block; aspect-ratio: 3/4; object-fit: cover;
}
.hero__eyebrow {
  margin: 0 0 10px; color: var(--accent); font-weight: 600;
  font-size: .82rem; letter-spacing: .04em; text-transform: uppercase;
}
.hero__name { font-family: var(--serif); font-size: clamp(2.4rem, 5vw, 3.4rem); font-weight: 600; letter-spacing: -.01em; }
.hero__sub { margin: 8px 0 0; color: var(--text-soft); font-size: 1.05rem; }
.hero__bio { margin: 20px 0 0; color: var(--text-soft); font-size: 1.02rem; max-width: 56ch; }
.hero__bio strong { color: var(--text); font-weight: 600; }
.hero__actions { margin: 26px 0 0; display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 10px 20px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--bg-elev); color: var(--text);
  font-weight: 500; font-size: .94rem; transition: all .2s ease;
}
.btn:hover { text-decoration: none; border-color: var(--accent); color: var(--accent); }
.btn--primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn--primary:hover { color: #fff; filter: brightness(1.06); }
.hero__meta { list-style: none; margin: 28px 0 0; padding: 0; display: flex; flex-wrap: wrap; gap: 8px 26px; color: var(--text-soft); font-size: .92rem; }
.hero__meta li { display: flex; align-items: center; gap: 8px; }
.hero__meta span { opacity: .85; }

/* ===== Notice ===== */
.notice { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.notice__inner {
  background: var(--accent-soft); border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
  border-radius: 14px; padding: 16px 22px; display: flex; gap: 16px; align-items: center; flex-wrap: wrap;
}
.notice__tag {
  background: var(--accent); color: #fff; font-size: .74rem; font-weight: 700;
  letter-spacing: .05em; text-transform: uppercase; padding: 5px 11px; border-radius: 999px; white-space: nowrap;
}
.notice__inner p { margin: 0; color: var(--text); font-size: .96rem; }
.notice__inner strong { color: var(--accent); font-weight: 600; }

/* ===== Stats ===== */
.stats {
  max-width: var(--maxw); margin: 48px auto 0; padding: 0 24px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
}
.stats__item {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: 14px;
  padding: 22px 18px; text-align: center;
}
.stats__item strong { display: block; font-family: var(--serif); font-size: 2rem; color: var(--accent); font-weight: 600; }
.stats__item span { color: var(--text-soft); font-size: .86rem; }

/* ===== Sections ===== */
.section { max-width: var(--maxw); margin: 0 auto; padding: 72px 24px 0; }
.section__title {
  font-family: var(--serif); font-size: 1.9rem; font-weight: 600; letter-spacing: -.01em;
  padding-bottom: 14px; margin-bottom: 28px; border-bottom: 1px solid var(--line);
}
.section__lead { color: var(--text-soft); margin: -14px 0 22px; }
.legend { display: inline-flex; align-items: center; gap: 8px; font-size: .86rem; }
.dot { width: 10px; height: 10px; border-radius: 50%; display: inline-block; }
.dot--corr { background: var(--hot); }

/* ===== Cards ===== */
.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.card {
  background: var(--bg-elev); border: 1px solid var(--line); border-radius: 16px;
  padding: 26px 24px; box-shadow: var(--shadow); transition: transform .2s ease, border-color .2s ease;
}
.card:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--accent) 40%, var(--line)); }
.card__icon { font-size: 1.8rem; margin-bottom: 12px; }
.card h3 { font-size: 1.12rem; margin-bottom: 8px; }
.card p { margin: 0; color: var(--text-soft); font-size: .95rem; }

/* ===== Publication filters ===== */
.pub-filters { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 26px; }
.chip {
  border: 1px solid var(--line); background: var(--bg-elev); color: var(--text-soft);
  padding: 7px 16px; border-radius: 999px; font-size: .88rem; font-weight: 500; cursor: pointer;
  font-family: var(--sans); transition: all .18s ease;
}
.chip:hover { border-color: var(--accent); color: var(--accent); }
.chip.is-active { background: var(--accent); border-color: var(--accent); color: #fff; }

/* ===== Publications ===== */
.pubs { list-style: none; margin: 0; padding: 0; }
.pub {
  display: grid; grid-template-columns: 64px 1fr; gap: 20px;
  padding: 22px 0; border-top: 1px solid var(--line);
}
.pub:first-child { border-top: none; }
.pub__year { font-family: var(--serif); font-size: 1.05rem; color: var(--text-faint); font-weight: 500; padding-top: 1px; }
.pub__title { margin: 0; font-weight: 600; font-size: 1.04rem; color: var(--text); }
.corr { color: var(--hot); font-size: .9em; margin-right: 2px; }
.pub__authors { margin: 5px 0 0; color: var(--text-soft); font-size: .93rem; }
.pub__authors strong { color: var(--text); }
.pub__venue { margin: 3px 0 0; color: var(--text-soft); font-size: .92rem; }
.pub__tags { margin: 10px 0 0; display: flex; gap: 8px; flex-wrap: wrap; }
.tag {
  font-size: .74rem; font-weight: 600; letter-spacing: .02em; padding: 3px 10px; border-radius: 6px;
  background: var(--bg-soft); color: var(--text-soft); border: 1px solid var(--line);
}
.tag--hot { background: var(--hot-soft); color: var(--hot); border-color: color-mix(in srgb, var(--hot) 30%, transparent); }
.pub.is-hidden { display: none; }

/* ===== Research projects ===== */
.projects__asof { display: inline-block; margin-left: 16px; font-size: .875rem; }
.project-filters { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 26px; }
.projects { list-style: none; margin: 0; padding: 0; }
.project { padding: 28px 0; border-top: 1px solid var(--line); }
.project:first-child { border-top: none; padding-top: 0; }
.project[hidden] { display: none; }
.project__badges { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.project__status, .project__role {
  padding: 4px 10px; border: 1px solid var(--line); border-radius: 6px;
  font-size: .875rem; font-weight: 500; color: var(--text-soft); background: var(--bg-soft);
}
.project__status--ongoing { color: var(--accent); background: var(--accent-soft); border-color: var(--accent); }
.project__role { background: var(--bg-elev); color: var(--text); }
.project h3 { font-size: 1.15rem; line-height: 1.45; }
.project__original { margin: 5px 0 0; color: var(--text-soft); font-size: .875rem; word-break: keep-all; overflow-wrap: anywhere; }
.project__purpose { margin: 12px 0 16px; font-size: 1rem; color: var(--text-soft); }
.project__purpose a { white-space: normal; font-size: .875rem; text-decoration: underline; text-underline-offset: 3px; }
.project__details { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 28px; margin: 0; font-size: .875rem; }
.project__details > div { min-width: 0; }
.project__details dt { color: var(--text-soft); font-weight: 500; }
.project__details dd { margin: 2px 0 0; color: var(--text); overflow-wrap: anywhere; }
.project__source { margin: 12px 0 0; color: var(--text-soft); font-size: .8125rem; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.chip:focus-visible, .nav__links a:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }

/* ===== Two column (edu / exp) ===== */
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; }
.timeline { list-style: none; margin: 0; padding: 0; }
.timeline li { position: relative; padding: 0 0 26px 24px; border-left: 2px solid var(--line); }
.timeline li:last-child { padding-bottom: 0; }
.timeline li::before {
  content: ""; position: absolute; left: -7px; top: 4px; width: 12px; height: 12px;
  border-radius: 50%; background: var(--bg); border: 2px solid var(--accent);
}
.timeline__date { font-size: .82rem; color: var(--accent); font-weight: 600; }
.timeline h3 { font-size: 1.05rem; margin: 2px 0 2px; }
.timeline p { margin: 0; color: var(--text-soft); font-size: .93rem; }

/* ===== Contact ===== */
.section--contact { padding-bottom: 24px; }
.contact__lead { color: var(--text-soft); font-size: 1.05rem; max-width: 52ch; margin: 0 0 24px; }
.contact__list { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 14px 40px; }
.contact__list li { display: flex; gap: 16px; align-items: baseline; border-bottom: 1px solid var(--line); padding-bottom: 12px; }
.contact__k { width: 84px; flex: none; color: var(--text-faint); font-size: .82rem; text-transform: uppercase; letter-spacing: .04em; font-weight: 600; }

/* ===== Footer ===== */
.footer {
  max-width: var(--maxw); margin: 72px auto 0; padding: 32px 24px 48px;
  border-top: 1px solid var(--line); color: var(--text-faint); font-size: .88rem;
}
.footer p { margin: 0; }
.footer__sub { margin-top: 6px; }

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .nav__inner { height: auto; min-height: 60px; flex-wrap: wrap; gap: 8px 16px; padding-top: 10px; padding-bottom: 10px; }
  .nav__links { order: 3; width: 100%; margin: 0; gap: 10px 18px; flex-wrap: wrap; }
  .theme-toggle { margin-left: auto; }
  html { scroll-padding-top: 130px; }
  .hero { grid-template-columns: 1fr; gap: 32px; padding-top: 48px; text-align: left; }
  .hero__photo { max-width: 180px; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .cards { grid-template-columns: 1fr; }
  .two-col { grid-template-columns: 1fr; gap: 40px; }
  .contact__list { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .nav__links { display: flex; }
  .project__details { grid-template-columns: 1fr; gap: 10px; }
  .projects__asof { display: block; margin: 5px 0 0; }
  .pub { grid-template-columns: 1fr; gap: 6px; }
  .pub__year { font-size: .92rem; }
  .section__title { font-size: 1.6rem; }
}
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto; transition: none !important; }
}