/* Landing page — single-page academic site.
   Layout: sticky mono top bar; hero with portrait, role and links;
   research as a vertical timeline with bracketed actions; contact list; theme toggle. */

:root {
  --bg: #f5f6f8;
  --bg-elev: #ffffff;
  --glow: rgba(176, 109, 0, 0.07);
  --fg: #131923;
  --muted: #5a6474;
  --faint: #8a93a2;
  --rule: #d8dde5;
  --accent: #a96500;
  --accent-ink: #7f4b00;
  --accent-soft: rgba(169, 101, 0, 0.12);
  --curve: rgba(169, 101, 0, 0.32);
  --shadow: 0 10px 30px rgba(19, 25, 35, 0.10);

  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;

  --wrap: 980px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e131c;
    --bg-elev: #151c28;
    --glow: rgba(64, 104, 170, 0.22);
    --fg: #e6eaf0;
    --muted: #97a1b2;
    --faint: #6b7587;
    --rule: #263042;
    --accent: #f2b544;
    --accent-ink: #ffd27a;
    --accent-soft: rgba(242, 181, 68, 0.13);
    --curve: rgba(242, 181, 68, 0.30);
    --shadow: 0 12px 34px rgba(0, 0, 0, 0.35);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0e131c;
  --bg-elev: #151c28;
  --glow: rgba(64, 104, 170, 0.22);
  --fg: #e6eaf0;
  --muted: #97a1b2;
  --faint: #6b7587;
  --rule: #263042;
  --accent: #f2b544;
  --accent-ink: #ffd27a;
  --accent-soft: rgba(242, 181, 68, 0.13);
  --curve: rgba(242, 181, 68, 0.30);
  --shadow: 0 12px 34px rgba(0, 0, 0, 0.35);
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-padding-top: 72px; }
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }

body {
  margin: 0;
  background:
    radial-gradient(1100px 520px at 18% -8%, var(--glow), transparent 70%),
    var(--bg);
  background-attachment: fixed;
  color: var(--fg);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-ink); text-decoration: none; }
a:hover { color: var(--accent); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }

.skip {
  position: absolute; left: -9999px; top: 8px;
  font-family: var(--mono); font-size: 13px;
  background: var(--bg-elev); padding: 6px 10px; border: 1px solid var(--rule);
}
.skip:focus { left: 16px; z-index: 50; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}
.topbar__inner {
  max-width: var(--wrap); margin: 0 auto;
  padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  font-family: var(--mono); font-size: 13px;
}
.topbar__brand { color: var(--fg); font-weight: 500; letter-spacing: 0.01em; }
.topbar__links { list-style: none; margin: 0 0 0 auto; padding: 0; display: flex; gap: 6px; }
.topbar__links a {
  color: var(--muted); padding: 4px 10px; border-radius: 4px;
  transition: color .15s, background-color .15s;
}
.topbar__links a:hover { color: var(--fg); background: var(--accent-soft); }
.topbar__links a.is-active { color: var(--accent-ink); }

/* ---------- hero ---------- */
.hero { position: relative; overflow: hidden; }
.hero__inner {
  position: relative; z-index: 1;
  max-width: var(--wrap); margin: 0 auto;
  padding: 88px 24px 72px;
  display: grid; grid-template-columns: 200px minmax(0, 1fr); gap: 56px; align-items: center;
}
.hero__photo {
  width: 200px; height: 200px; border-radius: 50%; object-fit: cover; object-position: 50% 30%;
  border: 2px solid var(--accent);
  box-shadow: 0 0 0 6px var(--accent-soft), var(--shadow);
  max-width: 100%;
}
.hero__text { min-width: 0; }
.hero__name {
  font-family: var(--mono); font-weight: 700;
  font-size: clamp(30px, 4.4vw, 44px); line-height: 1.1; letter-spacing: -0.02em;
  margin: 0 0 14px; text-wrap: balance;
}
.hero__role { font-family: var(--mono); font-size: 15px; color: var(--accent-ink); margin: 0 0 18px; }
.hero__slash { color: var(--faint); margin-right: 4px; }
.hero__tags { list-style: none; padding: 0; margin: 0 0 20px; display: flex; flex-wrap: wrap; gap: 8px; }
.hero__tags li {
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.02em;
  color: var(--muted); border: 1px solid var(--rule); border-radius: 999px; padding: 3px 11px;
  background: var(--bg-elev);
}
.hero__about { max-width: 62ch; color: var(--fg); }
.hero__about p { margin: 0 0 12px; }
.hero__links { list-style: none; padding: 0; margin: 18px 0 0; display: flex; flex-wrap: wrap; gap: 6px 18px; }


/* ---------- bracketed actions ---------- */
.bracket {
  font-family: var(--mono); font-size: 13.5px; color: var(--fg);
  background: none; border: 0; padding: 0; cursor: pointer;
  display: inline-flex; align-items: center;
}
.bracket::before, .bracket::after { color: var(--accent); transition: transform .15s; }
.bracket::before { content: "["; margin-right: 3px; }
.bracket::after { content: "]"; margin-left: 3px; }
.bracket:hover { color: var(--accent-ink); }
.bracket:hover::before { transform: translateX(-2px); }
.bracket:hover::after { transform: translateX(2px); }
.bracket--btn[aria-expanded="true"] { color: var(--accent-ink); }

/* ---------- sections ---------- */
.section { max-width: var(--wrap); margin: 0 auto; padding: 40px 24px 56px; }
.section__title {
  font-family: var(--mono); font-weight: 500; font-size: 15px;
  text-transform: uppercase; letter-spacing: 0.14em; color: var(--fg);
  display: flex; align-items: center; gap: 12px; margin: 0 0 28px;
}
.section__title span { color: var(--accent); }
.section__title::after { content: ""; flex: 1; height: 1px; background: var(--rule); }

.group__title {
  font-family: var(--mono); font-weight: 500; font-size: 12px;
  text-transform: uppercase; letter-spacing: 0.12em; color: var(--muted);
  margin: 0 0 18px;
}

/* ---------- research timeline ---------- */
.timeline { list-style: none; margin: 0 0 32px; padding: 0 0 0 28px; position: relative; }
.timeline::before {
  content: ""; position: absolute; left: 5px; top: 10px; bottom: 10px; width: 1px; background: var(--rule);
}
.paper { position: relative; padding: 4px 0 30px; }
.paper:last-child { padding-bottom: 6px; }
.paper::before {
  content: ""; position: absolute; left: -28px; top: 12px;
  width: 11px; height: 11px; border-radius: 50%;
  background: var(--bg); border: 2px solid var(--accent);
}
.paper:first-child::before { background: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
.paper__title {
  font-family: var(--serif); font-weight: 600; font-size: 21px; line-height: 1.35;
  margin: 0 0 4px; text-wrap: balance;
}
.paper__title a { color: var(--fg); background-image: linear-gradient(var(--accent), var(--accent)); background-size: 0 1px; background-position: 0 100%; background-repeat: no-repeat; transition: background-size .25s, color .15s; }
.paper__title a:hover { color: var(--accent-ink); background-size: 100% 1px; }
.paper__with { margin: 0 0 10px; color: var(--muted); font-style: italic; font-size: 16.5px; }
.paper__with a.coauthor { color: inherit; text-decoration: underline; text-decoration-color: var(--rule); text-decoration-thickness: 1px; text-underline-offset: 3px; }
.paper__with a.coauthor:hover { color: var(--accent-ink); text-decoration-color: currentColor; }
.paper__venue { margin: 0 0 10px; font-family: var(--mono); font-size: 13px; color: var(--accent-ink); }
.paper__tagline { margin: 0 0 10px; max-width: 70ch; font-size: 16.5px; line-height: 1.55; color: var(--fg); opacity: .86; }
.paper__links { display: flex; flex-wrap: wrap; gap: 6px 18px; }
.presented {
  margin: 4px 0 0; max-width: 72ch; font-size: 15px; color: var(--muted);
  padding-top: 16px; border-top: 1px dashed var(--rule);
}
.presented span {
  font-family: var(--mono); font-size: 11.5px; text-transform: uppercase; letter-spacing: 0.12em;
  color: var(--muted); margin-right: 8px;
}
.paper__abstract {
  margin-top: 14px; padding: 14px 18px; max-width: 72ch;
  background: var(--bg-elev); border: 1px solid var(--rule); border-left: 2px solid var(--accent);
  border-radius: 0 6px 6px 0; font-size: 16.5px; line-height: 1.65; color: var(--fg);
}
.paper__abstract p { margin: 0; }

/* ---------- news ---------- */
.news { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.news li { display: grid; grid-template-columns: 96px minmax(0, 1fr); gap: 18px; align-items: baseline; }
.news__date { font-family: var(--mono); font-size: 12.5px; color: var(--accent-ink); letter-spacing: 0.02em; white-space: nowrap; }
.news__text { font-size: 16.5px; }
.news__text em { font-style: italic; }

/* ---------- contact ---------- */
.contact { margin: 0; display: grid; gap: 10px; }
.contact div { display: grid; grid-template-columns: 110px minmax(0, 1fr); gap: 16px; align-items: baseline; }
.contact dt { font-family: var(--mono); font-size: 12px; text-transform: uppercase; letter-spacing: 0.12em; color: var(--muted); }
.contact dd { margin: 0; overflow-wrap: anywhere; }
.contact__list { display: flex; flex-direction: column; gap: 4px; }
.contact__inline { display: flex; flex-wrap: wrap; align-items: baseline; }
.contact__inline a + a::before { content: "\00b7"; color: var(--muted); padding: 0 10px; display: inline-block; }
.contact a { text-decoration: underline; text-decoration-color: var(--rule); text-underline-offset: 3px; }
.contact a:hover { text-decoration-color: currentColor; }

/* ---------- footer & toggle ---------- */
.footer {
  max-width: var(--wrap); margin: 0 auto; padding: 24px 24px 48px;
  border-top: 1px solid var(--rule);
  font-family: var(--mono); font-size: 12px; color: var(--faint);
}
.footer p { margin: 0; }

.theme-toggle {
  width: 32px; height: 32px; border-radius: 6px; flex: none;
  display: grid; place-items: center; cursor: pointer;
  background: transparent; color: var(--muted); border: 1px solid var(--rule);
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent-ink); }
.theme-toggle svg { width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; }
.theme-toggle .icon-moon { fill: currentColor; stroke: none; }
.icon-sun { display: none; }
:root[data-theme="dark"] .icon-sun { display: block; }
:root[data-theme="dark"] .icon-moon { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .icon-sun { display: block; }
  :root:not([data-theme="light"]) .icon-moon { display: none; }
}

/* ---------- small screens ---------- */
@media (max-width: 760px) {
  body { font-size: 17px; }
  .topbar__inner { padding: 12px 16px; }
  .topbar__brand { display: none; }
  .topbar__links { flex: 1; margin: 0; justify-content: space-between; }
  .topbar__inner { flex-wrap: nowrap; }
  .hero__inner { grid-template-columns: 1fr; gap: 26px; padding: 44px 16px 44px; justify-items: start; }
  .hero__photo { width: 132px; height: 132px; }
  .section { padding: 28px 16px 40px; }
  .footer { padding: 20px 16px 40px; }
  .paper__title { font-size: 19px; }
  .contact div { grid-template-columns: 1fr; gap: 2px; }
  .news li { grid-template-columns: 1fr; gap: 0; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; }
}

/* ---------- plain pages (404) ---------- */
.plain { padding-top: 96px; padding-bottom: 120px; }