/* Site styles. Plain CSS, no build step.
   Colors are tokens on :root. Dark is the default for every visitor; the
   light values apply when the visitor switches to light (data-theme="light"). */

:root {
  --bg: #0f1217;
  --surface: #171b22;
  --text: #e6e8ec;
  --muted: #a3abb8;
  --faint: #7c8594;
  --border: #272d37;
  --accent: #8bbfff;
  --accent-hover: #b3d5ff;
  --accent-soft: #1a2739;
  --figure-bg: #f4f4f1;
  --pub-authors: #c3c9d3;      /* author lists: brighter than --muted */
  --control-bg: #1c222c;       /* buttons: lifted fill */
  --control-border: #5a6476;   /* buttons: 3.1:1 against the page */
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 6px 20px rgba(0, 0, 0, 0.25);
  --radius: 12px;
  --measure: 42rem;
  --wide: 60rem;
  color-scheme: dark;
}

:root[data-theme="light"] {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --text: #1c1f24;
  --muted: #5d6470;
  --faint: #6b717c;
  --border: #e6e3dc;
  --accent: #1f5c99;
  --accent-hover: #174a7c;
  --accent-soft: #eaf1f9;
  --figure-bg: #ffffff;
  --pub-authors: #3f454f;
  --control-bg: #ffffff;
  --control-border: #8d8a82;   /* 3.3:1 against the page */
  --shadow: 0 1px 2px rgba(20, 24, 31, 0.05), 0 4px 16px rgba(20, 24, 31, 0.05);
  color-scheme: light;
}

/* ---------- Base ---------- */

*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 5rem;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 1.0625rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main { flex: 1; width: 100%; max-width: var(--wide); margin: 0 auto; padding: 2.5rem 1.25rem 4rem; }
main.page > :not(.wide) { max-width: var(--measure); }

h1, h2, h3 { line-height: 1.25; letter-spacing: -0.015em; font-weight: 650; }
h1 { font-size: 2.1rem; margin: 0 0 1rem; }
h2 { font-size: 1.4rem; margin: 2.75rem 0 0.75rem; }
h3 { font-size: 1.1rem; margin: 1.75rem 0 0.4rem; }
p { margin: 0 0 1rem; }
ul { padding-left: 1.2rem; }
li { margin: 0.2rem 0; }
img { max-width: 100%; height: auto; }
em { font-style: italic; }

a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  text-decoration-color: color-mix(in srgb, var(--accent) 40%, transparent);
}
a:hover { color: var(--accent-hover); text-decoration-color: currentColor; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

.skip-link { position: absolute; left: -999px; top: 0.5rem; background: var(--surface); padding: 0.5rem 0.75rem; z-index: 20; }
.skip-link:focus { left: 0.5rem; }

.muted { color: var(--muted); }
.small { font-size: 0.875rem; }

/* ---------- Header / navigation ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  -webkit-backdrop-filter: saturate(1.4) blur(10px);
  backdrop-filter: saturate(1.4) blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0.7rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav-brand { font-weight: 650; font-size: 1.12rem; color: var(--text); text-decoration: none; white-space: nowrap; margin-right: auto; }
.nav-brand:hover { color: var(--accent); }

.nav-links { display: flex; gap: 0.25rem; list-style: none; margin: 0; padding: 0; }
.nav-links li { margin: 0; }
.nav-links a {
  display: block;
  padding: 0.4rem 0.75rem;
  border-radius: 8px;
  color: var(--muted);
  text-decoration: none;
  font-size: 1.02rem;
}
.nav-links a:hover { color: var(--text); background: var(--accent-soft); }
.nav-links a[aria-current="page"] { color: var(--text); background: var(--accent-soft); font-weight: 550; }

.theme-toggle {
  flex: none;
  width: 2.1rem;
  height: 2.1rem;
  display: grid;
  place-items: center;
  border: 1px solid var(--control-border);
  border-radius: 999px;
  background: var(--control-bg);
  color: var(--text);
  cursor: pointer;
}
.theme-toggle:hover { color: var(--text); }
.theme-toggle svg { width: 1.05rem; height: 1.05rem; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.theme-toggle .icon-moon { fill: currentColor; stroke: none; }
/* Show the sun in dark mode (click for light) and the moon in light mode. */
.icon-moon { display: none; }
:root[data-theme="light"] .icon-moon { display: block; }
:root[data-theme="light"] .icon-sun { display: none; }

@media (max-width: 40rem) {
  .nav { flex-wrap: wrap; row-gap: 0.35rem; padding: 0.6rem 1rem 0.5rem; }
  .nav-links { order: 3; width: calc(100% + 0.8rem); margin: 0 -0.4rem; justify-content: space-between; overflow-x: auto; scrollbar-width: none; }
  .nav-links::-webkit-scrollbar { display: none; }
  .nav-links a { padding: 0.3rem 0.4rem; font-size: 0.9rem; white-space: nowrap; }
  main { padding: 1.75rem 1rem 3rem; }
  h1 { font-size: 1.75rem; }
}

/* ---------- Footer ---------- */

.site-footer { border-top: 1px solid var(--border); color: var(--muted); font-size: 0.9rem; }
.footer-inner { max-width: var(--wide); margin: 0 auto; padding: 1.5rem 1.25rem 2rem; display: flex; flex-wrap: wrap; gap: 0.5rem 1.5rem; justify-content: space-between; }
.footer-links { display: flex; flex-wrap: wrap; gap: 0.25rem 1.25rem; }
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--text); }

/* ---------- Buttons ---------- */

.buttons { display: flex; flex-wrap: wrap; gap: 0.6rem; margin: 1.25rem 0 0; }
.button {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 0.95rem;
  border-radius: 999px;
  border: 1px solid var(--control-border);
  background: var(--control-bg);
  color: var(--text);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 550;
  line-height: 1.2;
}
.button:hover { border-color: var(--accent); color: var(--accent); }
.button.primary { background: var(--accent); border-color: var(--accent); color: var(--bg); }
.button.primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); color: var(--bg); }

/* ---------- Home ---------- */

.hero { display: grid; grid-template-columns: 9rem 1fr; gap: 2rem; align-items: center; margin: 0.5rem 0 1rem; }
.hero-photo { width: 9rem; height: 9rem; border-radius: 50%; object-fit: cover; object-position: 50% 30%; border: 1px solid var(--border); }
.hero h1 { font-size: 2.4rem; margin: 0 0 0.2rem; }
.hero-role { color: var(--muted); font-size: 1.1rem; margin: 0; }
.hero-intro { max-width: var(--measure); font-size: 1.12rem; margin: 1.5rem 0 0; }
.hero-intro p { margin: 0; }
@media (max-width: 40rem) {
  .hero { grid-template-columns: 5.5rem 1fr; gap: 1.1rem; }
  .hero-photo { width: 5.5rem; height: 5.5rem; }
  .hero h1 { font-size: 1.8rem; }
  .hero-role { font-size: 1rem; }
  .hero-intro { font-size: 1.05rem; }
}

.section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; margin: 3rem 0 1rem; }
.section-head h2 { margin: 0; }
.section-head a { font-size: 0.95rem; white-space: nowrap; }

/* ---------- Cards ---------- */

.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(17rem, 1fr)); gap: 1rem; }
.card {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  color: inherit;
  text-decoration: none;
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s;
}
a.card:hover { border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); box-shadow: var(--shadow); transform: translateY(-1px); color: inherit; }
.card-media { position: relative; aspect-ratio: 16 / 9; background: var(--figure-bg); overflow: hidden; border-bottom: 1px solid var(--border); }
.card-media img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.card-media.contain img { object-fit: contain; padding: 0.5rem; }
.card-body { padding: 0.95rem 1.1rem 1.1rem; display: flex; flex-direction: column; gap: 0.35rem; flex: 1; }
.card-title { font-weight: 650; font-size: 1.05rem; line-height: 1.3; margin: 0; }
.card-text { color: var(--muted); font-size: 0.95rem; line-height: 1.5; margin: 0; }
.card-more { margin-top: auto; padding-top: 0.4rem; color: var(--accent); font-size: 0.9rem; font-weight: 550; }
.card-credit { font-size: 0.75rem; color: var(--faint); margin: 0; }

.link-row { display: flex; flex-wrap: wrap; gap: 0.4rem 0.9rem; margin: 0.4rem 0 0; padding: 0; list-style: none; font-size: 0.92rem; }
.link-row li { margin: 0; }

/* ---------- Figures ---------- */

figure { margin: 1.5rem 0 2rem; }
figure .frame { background: var(--figure-bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 0.75rem; }
figure img { display: block; margin: 0 auto; }
figcaption { color: var(--muted); font-size: 0.875rem; line-height: 1.5; margin-top: 0.6rem; }

/* ---------- Research page ---------- */

.jump { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 1.25rem 0 0.5rem; padding: 0; list-style: none; }
.jump li { margin: 0; }
.jump a { display: inline-block; padding: 0.3rem 0.8rem; border: 1px solid var(--control-border); border-radius: 999px; background: var(--control-bg); color: var(--text); text-decoration: none; font-size: 0.9rem; }
.jump a:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- Publications ---------- */

.pub-toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 0.75rem 1rem; margin: 0.5rem 0 1.5rem; }
.segmented { display: inline-flex; border: 1px solid var(--control-border); border-radius: 999px; padding: 3px; background: var(--control-bg); }
.segmented button { border: 0; background: none; color: var(--muted); font: inherit; font-size: 0.92rem; padding: 0.3rem 0.85rem; border-radius: 999px; cursor: pointer; }
.segmented button[aria-pressed="true"] { background: var(--accent-soft); color: var(--text); font-weight: 550; }
.pub-year { display: grid; grid-template-columns: 4.5rem 1fr; gap: 0 1rem; border-top: 1px solid var(--border); padding-top: 1rem; margin-bottom: 0.5rem; }
.pub-year h2 { font-size: 1.2rem; font-weight: 700; margin: 0.05rem 0 0; color: var(--text); font-variant-numeric: tabular-nums; }
.pub-list { list-style: none; margin: 0; padding: 0; }
.pub { margin: 0 0 1.5rem; line-height: 1.5; }
.pub-title { font-weight: 550; font-size: 1.1rem; line-height: 1.4; margin-bottom: 0.25rem; }
.pub-title a { color: var(--text); text-decoration: none; }
.pub-title a:hover { color: var(--accent); }
.pub-authors { color: var(--pub-authors); font-size: 0.97rem; margin-bottom: 0.1rem; }
.pub-authors strong { color: var(--accent); font-weight: 700; }
.pub-meta { font-size: 0.93rem; color: var(--muted); display: flex; flex-wrap: wrap; align-items: center; gap: 0.2rem 0.9rem; }
.pub-meta a { font-weight: 550; }
.badge { display: inline-block; font-size: 0.72rem; font-weight: 600; letter-spacing: 0.02em; text-transform: uppercase; color: var(--accent); background: var(--accent-soft); border-radius: 4px; padding: 0.05rem 0.35rem; vertical-align: 0.1em; margin-right: 0.15rem; }
.only-first .pub:not(.is-first),
.only-first .pub-year[data-has-first="false"] { display: none; }
@media (max-width: 40rem) {
  .pub-year { grid-template-columns: 1fr; }
  .pub-year h2 { margin-bottom: 0.5rem; }
}

/* Short list on the home page */
.pub-compact { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--border); }
.pub-compact li { margin: 0; padding: 0.8rem 0; border-bottom: 1px solid var(--border); display: grid; grid-template-columns: 1fr auto; gap: 0.25rem 1rem; align-items: baseline; }
.pub-compact a { color: var(--text); text-decoration: none; font-weight: 550; }
.pub-compact a:hover { color: var(--accent); }
.pub-compact .pub-meta { white-space: nowrap; }
@media (max-width: 40rem) { .pub-compact li { grid-template-columns: 1fr; } }

/* ---------- CV ---------- */

.cv-section { margin: 2.25rem 0 0; }
.cv-section h2 { font-size: 1.15rem; margin: 0 0 0.6rem; }
.cv-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--border); }
.cv-list li { display: grid; grid-template-columns: 1fr auto; gap: 0.1rem 1.5rem; margin: 0; padding: 0.6rem 0; border-bottom: 1px solid var(--border); }
.cv-what { font-weight: 550; }
.cv-detail { color: var(--muted); font-size: 0.93rem; grid-column: 1; }
.cv-when { color: var(--faint); font-size: 0.92rem; font-variant-numeric: tabular-nums; white-space: nowrap; grid-column: 2; grid-row: 1; text-align: right; }
@media (max-width: 40rem) {
  .cv-list li { grid-template-columns: 1fr; }
  .cv-when { grid-column: 1; grid-row: auto; text-align: left; }
}

/* ---------- Code & media ---------- */

.project-logo { width: 2rem; height: 2rem; object-fit: contain; vertical-align: middle; margin-right: 0.45rem; }
.card .card-body .link-row a { font-weight: 550; }
.source { display: inline-block; font-size: 0.78rem; font-weight: 600; color: var(--muted); border: 1px solid var(--border); border-radius: 999px; padding: 0.05rem 0.55rem; margin-right: 0.35rem; }

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

/* A page title followed directly by a section heading (CV, Media). */
.page-title + h2,
.page-title + p + h2 { margin-top: 1.25rem; }

/* Two images in one figure: equal height side by side, stacked on phones. */
.frame.pair { display: flex; gap: 0.75rem; align-items: flex-start; }
.frame.pair img { min-width: 0; width: 100%; margin: 0; }
@media (max-width: 40rem) {
  .frame.pair { flex-direction: column; }
  .frame.pair img { flex: none !important; }
}

/* Home: the longer "about" text continues the intro, in the same column. */
.hero-more { max-width: var(--measure); margin-top: 1rem; }
.hero-intro p, .hero-more p { margin: 0 0 0.9rem; }

/* Home: quick links under the name. The email button shows the address. */
.hero-links { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.9rem; }
.hero-links .button { font-size: 0.92rem; padding: 0.45rem 0.85rem; }
.button .icon { width: 1.05em; height: 1.05em; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
@media (max-width: 40rem) {
  .hero > div { display: contents; }
  .hero { row-gap: 0.1rem; }
  .hero h1 { grid-column: 2; grid-row: 1; align-self: end; }
  .hero-role { grid-column: 2; grid-row: 2; align-self: start; }
  .hero-photo { grid-column: 1; grid-row: 1 / span 2; }
  .hero-links { grid-column: 1 / -1; grid-row: 3; margin-top: 0.9rem; }
}

/* Dark figures shown edge to edge, without the light frame. */
.frame.bare { background: none; border: 0; padding: 0; overflow: hidden; }
.frame.bare img { border-radius: var(--radius); }

/* Small brand icons in link lists (Code page). */
svg.brand { width: 1em; height: 1em; vertical-align: -0.14em; margin-right: 0.4em; }
.brand-links { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: 0.5rem 1.4rem; }
.brand-links li { margin: 0; }
.brand-links a { white-space: nowrap; }

/* Square project icons: faint outline so dark tiles stay visible in dark mode. */
img.project-logo[src*="/icons/"] { border-radius: 26%; box-shadow: 0 0 0 1px color-mix(in srgb, var(--text) 16%, transparent); }

/* Email button with an attached copy button. */
.email-group { display: inline-flex; }
.email-group .email-link { border-top-right-radius: 0; border-bottom-right-radius: 0; }
.email-group .copy-email {
  border-top-left-radius: 0; border-bottom-left-radius: 0; margin-left: 1px;
  padding-left: 0.65rem; padding-right: 0.75rem; cursor: pointer; font: inherit;
}
.copy-email .icon-check { display: none; }
.copy-email.copied .icon-check { display: block; }
.copy-email.copied .icon-copy { display: none; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* Comfortable tap targets for small standalone links (footer, publication links). */
.site-footer a { display: inline-block; padding: 0.3rem 0; }
.pub-meta a { display: inline-block; padding: 0.2rem 0.1rem; }
@media (max-width: 40rem) {
  .site-footer a { padding: 0.55rem 0; }
  .pub-meta a { padding: 0.45rem 0.2rem; }
}

/* Publications: editorial style. Serif titles (Source Serif 4,
   loaded only on this page), italic journal lines, outlined link tags,
   thin rules between papers. */
.pub-title { font-family: "Source Serif 4", Georgia, "Times New Roman", serif; font-size: 1.22rem; font-weight: 600; letter-spacing: -0.005em; }
.pub-meta > span:first-child { font-style: italic; }
.pub-meta > span:first-child .badge { font-style: normal; }
.pub-meta a { border: 1px solid var(--control-border); border-radius: 6px; padding: 0.1rem 0.5rem; text-decoration: none; font-size: 0.85rem; }
.pub-meta a:hover { border-color: var(--accent); }
.pub { padding-bottom: 1.1rem; border-bottom: 1px solid var(--border); }
.pub:last-child { border-bottom: 0; }
@media (max-width: 40rem) {
  .pub-meta a { padding: 0.4rem 0.65rem; }
}

/* Preprint tag in neutral gray so the blue stays reserved for my name. */
.badge { color: var(--muted); background: color-mix(in srgb, var(--text) 9%, transparent); }