/* ============================================================
   SHARED STYLESHEET — every page links to this one file.
   You normally won't need to touch this. The block right below
   (THEME) is the only part we'll change when we pick the final
   colors and fonts.
============================================================ */

/* ---------- THEME: fonts + colors (we'll swap this later) ---------- */
@import url('https://fonts.googleapis.com/css2?family=Archivo:wght@400;500;600;700&family=IBM+Plex+Sans:wght@400;500;600&family=IBM+Plex+Mono:wght@400;500&display=swap');

:root {
  --paper:      #F4F5F9;
  --card:       #FFFFFF;
  --ink:        #161B2E;
  --muted:      #5B6172;
  --spruce:     #263471;
  --spruce-deep:#171F49;
  --ochre:      #5E6AD2;
  --mark:       rgba(94,106,210,0.26);
  --line:       #DFE1EC;

  --serif: "Archivo", system-ui, sans-serif;
  --sans:  "IBM Plex Sans", system-ui, sans-serif;
  --mono:  "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, monospace;

  --maxw: 940px;
}

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--spruce); text-decoration: none; }
a:hover { color: var(--spruce-deep); }

.eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--spruce);
  margin: 0 0 14px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.eyebrow::after { content: ""; flex: 1; height: 1px; background: var(--line); }

/* Signature "study-notes highlighter" swipe. Wrap text in <mark>. */
mark {
  background: linear-gradient(180deg, transparent 55%, var(--mark) 55%);
  color: inherit;
  padding: 0 1px;
}

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }

section { padding: 68px 0; }
section + section { border-top: 1px solid var(--line); }

/* ---------- Top bar / navigation (same on every page) ---------- */
header.topbar {
  position: sticky; top: 0; z-index: 20;
  background: rgba(241,243,242,0.82);
  backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--line);
}
.topbar .wrap { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.brand { font-family: var(--mono); font-size: 13px; letter-spacing: 0.06em; color: var(--ink); font-weight: 500; }
.brand:hover { color: var(--spruce); }
.brand .dot { color: var(--ochre); }
nav.menu { display: flex; gap: 26px; }
nav.menu a { font-family: var(--mono); font-size: 12.5px; letter-spacing: 0.05em; color: var(--muted); }
nav.menu a:hover { color: var(--spruce); }
nav.menu a[aria-current="page"] { color: var(--ink); font-weight: 500; }

/* ---------- Hero (home page) ---------- */
.hero { padding: 84px 0 72px; }
.hero .kicker { font-family: var(--mono); font-size: 12.5px; letter-spacing: 0.16em; text-transform: uppercase; color: var(--spruce); margin: 0 0 20px; }
.hero h1 { font-family: var(--serif); font-weight: 500; font-size: clamp(2.7rem, 7vw, 4.6rem); line-height: 1.02; letter-spacing: -0.015em; margin: 0 0 22px; }
.hero .lede { font-size: 1.22rem; color: var(--ink); max-width: 42ch; margin: 0 0 34px; }

.facts { display: flex; flex-wrap: wrap; gap: 14px 40px; padding-top: 28px; border-top: 1px solid var(--line); }
.facts div { min-width: 150px; }
.facts dt { font-family: var(--mono); font-size: 11px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); margin-bottom: 4px; }
.facts dd { margin: 0; font-weight: 500; }

/* ---------- Page header (sub-pages) ---------- */
.pagehead { padding: 64px 0 44px; }
.pagehead .kicker { font-family: var(--mono); font-size: 12.5px; letter-spacing: 0.16em; text-transform: uppercase; color: var(--spruce); margin: 0 0 16px; }
.pagehead h1 { font-family: var(--serif); font-weight: 500; font-size: clamp(2.2rem, 5.5vw, 3.4rem); line-height: 1.05; letter-spacing: -0.015em; margin: 0 0 18px; }
.pagehead .lede { font-size: 1.12rem; color: var(--muted); max-width: 56ch; margin: 0; }

h2.title { font-family: var(--serif); font-weight: 500; font-size: clamp(1.7rem, 4vw, 2.35rem); letter-spacing: -0.01em; margin: 0 0 26px; }

/* ---------- Record rows (education, CV lists) ---------- */
.record { display: grid; grid-template-columns: 170px 1fr; gap: 8px 32px; padding: 22px 0; border-top: 1px solid var(--line); }
.record:first-of-type { border-top: none; }
.record .when { font-family: var(--mono); font-size: 13px; color: var(--muted); padding-top: 3px; }
.record h3 { font-family: var(--serif); font-weight: 500; font-size: 1.3rem; margin: 0 0 2px; }
.record .place { color: var(--spruce); font-weight: 500; margin-bottom: 8px; }
.record p { margin: 0; color: var(--muted); }

/* ---------- Card grid (research interests, hobbies) ---------- */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 18px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 26px 24px; }
.card .tag { font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ochre); margin-bottom: 12px; }
.card h3 { font-family: var(--serif); font-weight: 500; font-size: 1.28rem; margin: 0 0 10px; }
.card p { margin: 0; color: var(--muted); font-size: 0.98rem; }

/* ---------- Project entries ---------- */
.proj { padding: 26px 0; border-top: 1px solid var(--line); }
.proj:first-of-type { border-top: none; }
.proj .meta { font-family: var(--mono); font-size: 12.5px; letter-spacing: 0.03em; color: var(--muted); margin: 0 0 8px; }
.proj h3 { font-family: var(--serif); font-weight: 500; font-size: 1.42rem; margin: 0 0 8px; }
.proj p { margin: 0; color: var(--muted); max-width: 68ch; }
.proj .links { display: flex; flex-wrap: wrap; gap: 18px; margin-top: 14px; }
.proj .links a { font-family: var(--mono); font-size: 12.5px; }
.proj .links a::before { content: "↗ "; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  font-family: var(--mono); font-size: 13px; letter-spacing: 0.03em;
  padding: 12px 20px; border-radius: 9px;
  background: var(--spruce); color: #fff; border: 1px solid var(--spruce);
}
.btn:hover { background: var(--spruce-deep); border-color: var(--spruce-deep); color: #fff; }
.btn.secondary { background: transparent; color: var(--spruce); }
.btn.secondary:hover { background: rgba(30,91,79,0.08); color: var(--spruce-deep); }
.btn svg { width: 15px; height: 15px; }

/* ---------- About ---------- */
.about p { max-width: 62ch; }
.about p + p { margin-top: 18px; }
.pills { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.pill { font-family: var(--mono); font-size: 12.5px; color: var(--ink); background: transparent; border: 1px solid var(--line); border-radius: 999px; padding: 7px 15px; }

/* ---------- Media embeds (Spotify, etc.) ---------- */
.embed { border-radius: 12px; overflow: hidden; border: 1px solid var(--line); background: var(--card); margin-top: 16px; }
.embed iframe { display: block; width: 100%; border: 0; }
.embed-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }

/* ---------- Contact ---------- */
.contact-card { background: var(--spruce-deep); color: rgba(255,255,255,0.90); border-radius: 14px; padding: 40px 38px; }
.contact-card h2 { font-family: var(--serif); font-weight: 500; font-size: 2rem; margin: 0 0 8px; color: #fff; }
.contact-card p.sub { margin: 0 0 26px; color: rgba(255,255,255,0.62); max-width: 46ch; }
.contact-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px,1fr)); gap: 20px 32px; }
.contact-list .row .k { font-family: var(--mono); font-size: 11px; letter-spacing: 0.14em; text-transform: uppercase; color: rgba(255,255,255,0.55); margin-bottom: 4px; }
.contact-list .row a, .contact-list .row span { color: #fff; font-weight: 500; word-break: break-word; }
.contact-list .row a:hover { color: var(--ochre); }

/* ---------- Footer ---------- */
footer.foot { padding: 34px 0 48px; }
footer.foot .wrap { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; font-family: var(--mono); font-size: 12px; color: var(--muted); }

/* ---------- Motion ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in { opacity: 1; transform: none; }

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

/* ---------- Mobile ---------- */
@media (max-width: 640px) {
  nav.menu { gap: 16px; }
  nav.menu a { font-size: 11.5px; }
  .record { grid-template-columns: 1fr; gap: 4px; }
  .record .when { padding-top: 0; }
  .contact-card { padding: 30px 24px; }
  section { padding: 52px 0; }
}

/* ---------- Social links row (hobbies) ---------- */
.socials { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 4px; }

/* ---------- Photo carousel (hobbies) ---------- */
.carousel-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.carousel-nav { display: flex; gap: 8px; }
.carousel-nav button {
  width: 40px; height: 40px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--card);
  color: var(--ink); font-size: 18px; line-height: 1; cursor: pointer;
}
.carousel-nav button:hover { border-color: var(--spruce); color: var(--spruce); }
.carousel {
  display: flex; gap: 18px; margin-top: 22px;
  overflow-x: auto; scroll-snap-type: x mandatory;
  padding-bottom: 10px; scrollbar-width: thin;
}
.slide { flex: 0 0 clamp(260px, 76%, 500px); scroll-snap-align: center; margin: 0; }
.slide img { width: 100%; aspect-ratio: 3 / 2; object-fit: cover; border-radius: 12px; border: 1px solid var(--line); display: block; background: var(--card); }
.slide figcaption { font-family: var(--mono); font-size: 12.5px; color: var(--muted); margin-top: 12px; line-height: 1.5; }

/* ---------- Brand name (English / Chinese) ---------- */
.brand-sep { color: var(--muted); margin: 0 5px; }
/* Spread the Chinese characters so they breathe like the roman name;
   the negative margin keeps the trailing dot tucked in close. */
.brand-zh { letter-spacing: 0.22em; margin-right: -0.22em; }