:root {
  --bg: #0d1117;
  --bg-elev: #161b22;
  --bg-card: #141a21;
  --border: #27303a;
  --border-soft: #1e252d;
  --text: #e6edf3;
  --text-dim: #9aa6b2;
  --accent: #58a6ff;
  --accent-2: #a5d6ff;
  --accent-warm: #e3b341;
  --accent-glow: rgba(88, 166, 255, 0.14);
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: "Inter", system-ui, -apple-system, sans-serif;
  --serif: "Lora", Georgia, "Times New Roman", serif;
  --maxw: 1040px;
}

:root[data-theme="light"] {
  --bg: #fbfbfa;
  --bg-elev: #f3f4f1;
  --bg-card: #ffffff;
  --border: #d8dee4;
  --border-soft: #e8ebee;
  --text: #1c2024;
  --text-dim: #596069;
  --accent: #0b63c4;
  --accent-2: #0a4f9e;
  --accent-warm: #9a6700;
  --accent-glow: rgba(11, 99, 196, 0.08);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 70px; overflow-x: clip; }

/* Prevent any long string (math formulas, emails, URLs) from forcing
   the page wider than the viewport on small screens. */
p, li, h1, h2, h3, h4, .pub__title, .research__points li { overflow-wrap: break-word; word-break: break-word; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
em { color: var(--text); font-style: italic; }

/* ---------- NAV ---------- */
.nav {
  position: sticky; top: 0; z-index: 60;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.75rem clamp(1rem, 5vw, 3rem);
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav__brand {
  font-family: var(--mono); font-weight: 700; font-size: 1.05rem; color: var(--text);
  border: 1px solid var(--border); border-radius: 8px; padding: 0.2rem 0.55rem;
}
.nav__brand:hover { text-decoration: none; border-color: var(--accent); }
.nav__links { display: flex; align-items: center; gap: clamp(0.7rem, 2.4vw, 1.6rem); }
.nav__links > a { color: var(--text-dim); font-size: 0.9rem; font-weight: 500; }
.nav__links > a:hover { color: var(--text); text-decoration: none; }
.theme-toggle {
  background: none; border: 1px solid var(--border); color: var(--text);
  border-radius: 8px; width: 2rem; height: 2rem; cursor: pointer; font-size: 0.95rem;
}
.theme-toggle:hover { border-color: var(--accent); }
.nav__burger {
  display: none; background: none; border: 1px solid var(--border); color: var(--text);
  border-radius: 8px; width: 2.3rem; height: 2.3rem; font-size: 1.1rem; cursor: pointer;
}

/* ---------- LAYOUT ---------- */
main { max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(1rem, 5vw, 2rem); }
.section { padding: clamp(3rem, 7vw, 5.5rem) 0 1rem; }
.section__title {
  font-size: clamp(1.4rem, 4vw, 1.9rem); font-weight: 700; margin-bottom: 1.4rem;
  display: flex; align-items: baseline; gap: 0.7rem;
}
.section__num { font-family: var(--mono); font-size: 0.95rem; color: var(--accent); font-weight: 500; }
.section__intro { color: var(--text-dim); max-width: 680px; margin-bottom: 2rem; font-size: 1.02rem; }
.section__intro--tight { margin-bottom: 1.4rem; }
.subhead { font-size: 1.2rem; font-weight: 700; margin: 2.8rem 0 0.3rem; }

/* ---------- HERO ---------- */
.hero { min-height: calc(100vh - 58px); display: flex; align-items: center; position: relative; }
.hero::before {
  content: ""; position: absolute; top: 6%; left: -12%; width: 55%; height: 60%;
  background: radial-gradient(circle, var(--accent-glow), transparent 70%);
  filter: blur(40px); z-index: -1;
}
.hero__inner { max-width: 800px; padding: 2rem 0; }
.hero__avatar {
  width: 112px; height: 112px; border-radius: 50%; object-fit: cover;
  border: 2px solid var(--border); margin-bottom: 1.4rem; display: block;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.25);
}
.hero__eyebrow { font-family: var(--mono); color: var(--accent); font-size: 0.9rem; margin-bottom: 1rem; letter-spacing: 0.01em; }
.hero__title { font-size: clamp(2.3rem, 7.5vw, 4.2rem); font-weight: 800; line-height: 1.05; letter-spacing: -0.02em; margin-bottom: 1.3rem; }
.hero__title span { color: var(--accent); }
.hero__lede { font-size: clamp(1.02rem, 2.3vw, 1.25rem); color: var(--text-dim); max-width: 680px; margin-bottom: 2rem; }
.hero__lede strong { color: var(--text); font-weight: 600; }
.hero__cta { display: flex; gap: 0.8rem; flex-wrap: wrap; margin-bottom: 2.6rem; }
.hero__facts { list-style: none; display: flex; flex-wrap: wrap; gap: clamp(1.2rem, 5vw, 3rem); border-top: 1px solid var(--border-soft); padding-top: 1.6rem; }
.hero__facts li { display: flex; flex-direction: column; }
.hero__facts strong { font-size: 1.3rem; font-weight: 700; }
.hero__facts span { font-family: var(--mono); font-size: 0.78rem; color: var(--text-dim); }
.hero__facts .var { font-family: var(--serif); font-style: italic; }

/* ---------- BUTTONS ---------- */
.btn { display: inline-block; padding: 0.68rem 1.3rem; border-radius: 10px; font-weight: 600; font-size: 0.92rem; transition: transform 0.15s ease, border-color 0.15s ease, filter 0.15s ease; }
.btn:hover { text-decoration: none; transform: translateY(-2px); }
.btn--primary { background: var(--accent); color: #fff; }
.btn--primary:hover { filter: brightness(1.08); }
.btn--ghost { border: 1px solid var(--border); color: var(--text); }
.btn--ghost:hover { border-color: var(--accent); }

/* ---------- ABOUT ---------- */
.about { max-width: 740px; }
.about p { color: var(--text-dim); margin-bottom: 1.1rem; font-size: 1.05rem; }
.about strong { color: var(--text); font-weight: 600; }

/* ---------- TAGS ---------- */
.tag { font-family: var(--mono); font-size: 0.72rem; padding: 0.18rem 0.55rem; border-radius: 20px; background: var(--accent-glow); color: var(--accent); white-space: nowrap; }
.tag--sm { font-size: 0.68rem; padding: 0.14rem 0.45rem; }

/* ---------- RESEARCH ---------- */
.research { display: grid; gap: 1.2rem; }
.research__card { background: var(--bg-card); border: 1px solid var(--border); border-left: 3px solid var(--accent); border-radius: 12px; padding: 1.5rem clamp(1.1rem, 3vw, 1.7rem); transition: transform 0.18s ease, border-color 0.18s ease; }
.research__card:hover { transform: translateY(-3px); }
.research__top { display: flex; align-items: center; gap: 0.6rem; margin-bottom: 0.6rem; }
.research__icon { font-size: 1.3rem; }
.research__area { font-family: var(--mono); font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--accent-warm); }
.research__title { font-family: var(--serif); font-size: clamp(1.15rem, 3vw, 1.4rem); font-weight: 600; line-height: 1.25; margin-bottom: 0.35rem; }
.research__venue { font-family: var(--mono); font-size: 0.78rem; color: var(--text-dim); margin-bottom: 0.3rem; }
.research__advisor { font-size: 0.85rem; color: var(--text-dim); margin-bottom: 0.9rem; }
.research__advisor .is-placeholder { color: var(--accent-warm); font-style: italic; }
.research__points { list-style: none; margin-bottom: 1rem; }
.research__points li { position: relative; padding-left: 1.1rem; margin-bottom: 0.5rem; color: var(--text-dim); font-size: 0.95rem; }
.research__points li::before { content: "▸"; position: absolute; left: 0; color: var(--accent); }
.research__points strong { color: var(--text); font-weight: 600; }
.research__tags { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 1rem; }
.research__links { display: flex; flex-wrap: wrap; gap: 1rem; }
.research__link { font-family: var(--mono); font-size: 0.82rem; font-weight: 500; }

/* ---------- COLLABORATORS ---------- */
.collab { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1rem; }
.collab__card { background: var(--bg-elev); border: 1px solid var(--border); border-radius: 12px; padding: 1.2rem 1.3rem; }
.collab__card--placeholder { border-style: dashed; }
.collab__name { font-size: 1.05rem; font-weight: 700; margin-bottom: 0.2rem; }
.collab__role { font-size: 0.86rem; color: var(--accent); margin-bottom: 0.15rem; }
.collab__org { font-size: 0.84rem; color: var(--text-dim); margin-bottom: 0.6rem; }
.collab__note { font-size: 0.85rem; color: var(--text-dim); }

/* ---------- PUBLICATIONS ---------- */
.pubs { list-style: none; counter-reset: pub; display: grid; gap: 0.9rem; }
.pub { counter-increment: pub; }
.pub__link { display: flex; align-items: stretch; gap: 1rem; background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px; padding: 1.3rem clamp(1.1rem, 3vw, 1.6rem); transition: border-color 0.18s ease, transform 0.18s ease; }
.pub__link:hover { text-decoration: none; border-color: var(--accent); transform: translateY(-2px); }
.pub__link::before { content: counter(pub, decimal-leading-zero); font-family: var(--mono); font-size: 0.8rem; color: var(--text-dim); padding-top: 0.15rem; }
.pub__main { flex: 1; }
.pub__type { display: inline-block; font-family: var(--mono); font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.06em; padding: 0.1rem 0.5rem; border-radius: 5px; margin-bottom: 0.5rem; }
.pub__type--preprint { background: var(--accent-glow); color: var(--accent); }
.pub__type--project { background: color-mix(in srgb, var(--accent-warm) 18%, transparent); color: var(--accent-warm); }
.pub__title { font-family: var(--serif); font-size: 1.1rem; font-weight: 600; line-height: 1.3; margin-bottom: 0.3rem; }
.pub__meta { font-family: var(--mono); font-size: 0.76rem; color: var(--text-dim); margin-bottom: 0.5rem; }
.pub__summary { font-size: 0.92rem; color: var(--text-dim); }
.pub__cta { align-self: center; font-family: var(--mono); font-size: 0.82rem; font-weight: 600; color: var(--accent); white-space: nowrap; border: 1px solid var(--border); border-radius: 8px; padding: 0.4rem 0.7rem; }
.pub__link:hover .pub__cta { background: var(--accent); color: #fff; border-color: var(--accent); }

/* ---------- EXPERIENCE TIMELINE ---------- */
.timeline { position: relative; }
.timeline::before { content: ""; position: absolute; left: 7px; top: 6px; bottom: 6px; width: 2px; background: var(--border); }
.exp { position: relative; padding-left: 2.2rem; padding-bottom: 1.8rem; }
.exp__dot { position: absolute; left: 0; top: 6px; width: 16px; height: 16px; border-radius: 50%; background: var(--bg); border: 3px solid var(--accent); }
.exp--placeholder .exp__dot { border-color: var(--accent-warm); border-style: dashed; }
.exp__body { background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px; padding: 1.2rem clamp(1rem, 3vw, 1.5rem); }
.exp--placeholder .exp__body { border-style: dashed; }
.exp__head { display: flex; justify-content: space-between; align-items: baseline; gap: 0.8rem; flex-wrap: wrap; }
.exp__role { font-size: 1.08rem; font-weight: 700; }
.exp__date { font-family: var(--mono); font-size: 0.76rem; color: var(--text-dim); white-space: nowrap; }
.exp__org { font-size: 0.92rem; color: var(--accent); margin-bottom: 0.7rem; }
.exp__loc { color: var(--text-dim); }
.exp__points { list-style: none; margin-bottom: 0.9rem; }
.exp__points li { position: relative; padding-left: 1rem; margin-bottom: 0.4rem; color: var(--text-dim); font-size: 0.9rem; }
.exp__points li::before { content: "–"; position: absolute; left: 0; color: var(--accent); }
.exp__footer { display: flex; justify-content: space-between; align-items: center; gap: 1rem; flex-wrap: wrap; }
.exp__tags { display: flex; flex-wrap: wrap; gap: 0.35rem; }
.exp__repos { display: flex; flex-wrap: wrap; gap: 0.6rem; }
.exp__repo { font-family: var(--mono); font-size: 0.76rem; }
.exp__repo--private { color: var(--text-dim); }

/* ---------- SKILLS ---------- */
.skills { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; }
.skills__group { background: var(--bg-elev); border: 1px solid var(--border); border-radius: 12px; padding: 1.2rem; }
.skills__group h3 { font-size: 0.95rem; margin-bottom: 0.8rem; color: var(--accent); }
.skills__group ul { list-style: none; display: flex; flex-wrap: wrap; gap: 0.4rem; }
.skills__group li { font-family: var(--mono); font-size: 0.78rem; padding: 0.22rem 0.55rem; border: 1px solid var(--border); border-radius: 8px; color: var(--text-dim); }

/* ---------- CONTACT ---------- */
.section--contact { text-align: center; padding-bottom: 3.5rem; }
.section--contact .section__title { justify-content: center; }
.contact__lede { color: var(--text-dim); max-width: 540px; margin: 0 auto 1.6rem; font-size: 1.08rem; }
.contact__links { display: flex; gap: 0.8rem; justify-content: center; flex-wrap: wrap; }
.contact__loc { font-family: var(--mono); font-size: 0.8rem; color: var(--text-dim); margin-top: 1.4rem; }

/* ---------- FOOTER ---------- */
.footer { border-top: 1px solid var(--border); text-align: center; padding: 2rem 1rem; color: var(--text-dim); font-size: 0.82rem; font-family: var(--mono); }

/* ---------- REVEAL ---------- */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- RESPONSIVE ---------- */
@media (max-width: 720px) {
  .nav__burger { display: block; }
  .nav__links {
    position: fixed; top: 56px; right: 0; left: 0;
    flex-direction: column; align-items: flex-start; gap: 0;
    background: var(--bg-elev); border-bottom: 1px solid var(--border);
    padding: 0.5rem clamp(1rem, 5vw, 3rem) 1rem;
    transform: translateY(-130%); transition: transform 0.28s ease;
    max-height: calc(100vh - 56px); overflow-y: auto;
  }
  .nav__links.is-open { transform: translateY(0); }
  .nav__links > a { width: 100%; padding: 0.7rem 0; border-bottom: 1px solid var(--border-soft); }
  .theme-toggle { margin-top: 0.7rem; }
  .pub__link { flex-direction: column; gap: 0.7rem; }
  .pub__link::before { display: none; }
  .pub__cta { align-self: flex-start; }
  .exp__head { flex-direction: column; gap: 0.1rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn:hover, .research__card:hover, .pub__link:hover { transform: none; }
  .nav__links { transition: none; }
}