/* ===========================================================
   Katie Luo — personal site
   Warm + minimal academic. Palette & fonts carried over from
   the current site (my_rose / earth theme).
   =========================================================== */

:root {
  --bg:          #ffffff;
  --bg-soft:     #faf7f6;   /* warm off-white for alternating sections */
  --text:        #212529;
  --muted:       #707070;   /* current primary link/accent (gray) */
  --muted-2:     #8a8a8a;
  --link:        #707070;
  --link-hover:  #4a4a4a;
  --accent:      #f2a49d;   /* favicon salmon-pink, used sparingly */
  --accent-deep: #e5877f;
  --accent-soft: #fdeeec;
  --border:      #ececec;
  --maxw:        920px;
  --radius:      10px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 72px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Lora", Georgia, "Times New Roman", serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--link); text-decoration: none; transition: color .15s ease; }
a:hover { color: var(--link-hover); }

img { max-width: 100%; }

h1, h2, h3 { font-weight: 700; line-height: 1.25; }

/* mono eyebrow / labels */
.mono {
  font-family: "Cutive Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;
}

/* ---------- layout ---------- */
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

section { padding: 68px 0; border-top: 1px solid var(--border); }
section.soft { background: var(--bg-soft); }
section:first-of-type { border-top: none; }

.section-eyebrow {
  font-family: "Cutive Mono", monospace;
  text-transform: uppercase;
  letter-spacing: .16em;
  font-size: 12px;
  color: var(--accent-deep);
  margin: 0 0 6px;
}
.section-title { font-size: 30px; margin: 0 0 4px; }
.section-sub { color: var(--muted); margin: 0 0 32px; font-size: 15px; }

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.86);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 10px 24px;
  display: flex; align-items: center; gap: 18px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.brand:hover { color: var(--text); }
.logo-k {
  width: 30px; height: 30px; border-radius: 8px;
  background: var(--accent);
  color: #fff; font-weight: 700;
  display: grid; place-items: center;
  font-family: "Lora", serif; font-size: 19px; line-height: 1;
}
.nav-links { margin-left: auto; display: flex; gap: 20px; flex-wrap: wrap; }
.nav-links a {
  font-size: 14.5px; color: var(--muted);
  font-family: "Cutive Mono", monospace;
}
.nav-links a:hover { color: var(--accent-deep); }

/* ---------- hero / about ---------- */
.about-grid { display: grid; grid-template-columns: 250px 1fr; gap: 48px; align-items: start; }
.profile { text-align: center; position: sticky; top: 90px; }
.avatar {
  width: 200px; height: 200px; border-radius: 50%;
  object-fit: cover; border: 4px solid #fff;
  box-shadow: 0 6px 26px rgba(0,0,0,.10);
}
.profile h1 { font-size: 26px; margin: 18px 0 2px; }
.profile .role { color: var(--muted); font-size: 14.5px; margin: 2px 0; }
.profile .role a { color: var(--muted); }
.profile .role a:hover { color: var(--accent-deep); }

.socials { display: flex; justify-content: center; gap: 16px; margin-top: 16px; }
.socials a { color: var(--muted); font-size: 20px; }
.socials a:hover { color: var(--accent-deep); }

.lead { font-size: 18px; }
.lead p { margin: 0 0 16px; }

.interests { margin: 22px 0 0; }
.interests .section-eyebrow { margin-bottom: 8px; }
.chips { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 8px; }
.chips li {
  font-size: 13.5px; padding: 4px 12px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent-deep);
  border: 1px solid #f6d9d5;
}

/* clickable topic-nav chips under "Research Areas" */
.areas { margin-top: 22px; }
.areas-hint { text-transform: none; letter-spacing: 0; font-size: 11px; color: var(--muted-2); font-family: "Lora", serif; font-style: italic; }
.chips-nav li { list-style: none; }
.chip-nav {
  display: inline-block; font-size: 13px; padding: 4px 12px; border-radius: 999px;
  background: #fff; color: var(--muted); border: 1px solid var(--border);
}
.chip-nav:hover { background: var(--accent-soft); color: var(--accent-deep); border-color: var(--accent); }

.edu { margin-top: 22px; }
.edu ul { list-style: none; padding: 0; margin: 8px 0 0; }
.edu li { margin-bottom: 12px; }
.edu .course { margin: 0; font-weight: 700; font-size: 15.5px; }
.edu .inst { margin: 0; color: var(--muted); font-size: 14px; }

/* ---------- news ---------- */
.news { margin-top: 30px; }
.news-item { display: grid; grid-template-columns: 92px 1fr; gap: 14px; padding: 9px 0; border-top: 1px dashed var(--border); }
.news-item:first-of-type { border-top: none; }
.news-date { font-family: "Cutive Mono", monospace; font-size: 13px; color: var(--accent-deep); padding-top: 2px; }
.news-body { font-size: 15.5px; }

/* ---------- publications (collapsible accordion) ---------- */
.pub-topic { border-top: 1px solid var(--border); }
.pub-topic:first-of-type { border-top: none; }

.topic-toggle {
  width: 100%; display: flex; align-items: center; gap: 14px;
  background: none; border: none; cursor: pointer;
  padding: 17px 4px 17px 13px; text-align: left; color: inherit;
  border-left: 3px solid transparent;
  transition: border-color .15s ease, background .15s ease;
}
.topic-toggle:hover { background: rgba(242,164,157,.07); }
.pub-topic.is-open > .topic-toggle { border-left-color: var(--accent); }

.topic-head {
  flex: 1; min-width: 0;            /* allow the label to wrap instead of forcing overflow */
  overflow-wrap: break-word;
  font-family: "Cutive Mono", monospace;
  text-transform: uppercase; letter-spacing: .1em; font-size: 13.5px;
  color: var(--text);
}
.topic-count {
  font-family: "Cutive Mono", monospace; font-size: 12px;
  color: var(--muted); background: #fff; border: 1px solid var(--border);
  border-radius: 999px; padding: 1px 10px;
}
.pub-topic.is-open .topic-count { color: var(--accent-deep); border-color: var(--accent); }
.chev {
  font-size: 24px; line-height: 1; color: var(--muted-2);
  transition: transform .25s ease, color .15s ease;
}
.pub-topic.is-open .chev { transform: rotate(90deg); color: var(--accent-deep); }

/* smooth height collapse */
.topic-body { display: grid; grid-template-rows: 0fr; transition: grid-template-rows .3s ease; }
.topic-body.open { grid-template-rows: 1fr; }
.topic-inner { overflow: hidden; }
.topic-body.open .topic-inner { padding: 2px 0 14px; }

.pub { display: grid; grid-template-columns: 168px 1fr; gap: 20px; padding: 18px 0; border-top: 1px solid var(--border); }
.pub > div { min-width: 0; }        /* let the text column shrink; long titles/authors wrap */
.pub-title, .pub-authors, .pub-venue { overflow-wrap: break-word; }
.pub:first-child { border-top: none; }
.pub-thumb {
  width: 168px; border-radius: 8px; border: 1px solid var(--border);
  background: var(--bg-soft); align-self: start;
}
.pub-thumb.placeholder {
  aspect-ratio: 16/10; display: grid; place-items: center;
  color: var(--muted-2); font-family: "Cutive Mono", monospace; font-size: 12px;
}
.pub-title { font-size: 17.5px; font-weight: 700; margin: 0 0 3px; line-height: 1.35; }
.pub-title a { color: var(--text); }
.pub-title a:hover { color: var(--accent-deep); }
.pub-venue { margin: 0 0 6px; font-size: 14.5px; color: var(--muted); }
.pub-venue em { font-style: italic; }
.badge {
  display: inline-block; font-family: "Cutive Mono", monospace;
  font-size: 11px; text-transform: uppercase; letter-spacing: .06em;
  color: var(--accent-deep); border: 1px solid var(--accent);
  border-radius: 4px; padding: 0 5px; margin-left: 6px;
}
.pub-authors { margin: 0 0 10px; font-size: 14px; color: #555; line-height: 1.5; }
.pub-authors .me { font-weight: 700; color: var(--text); }

.btns { display: flex; flex-wrap: wrap; gap: 7px; }
.btn {
  font-family: "Cutive Mono", monospace; font-size: 12px;
  padding: 3px 11px; border-radius: 5px;
  border: 1px solid var(--border); color: var(--muted); background: #fff;
}
.btn:hover { border-color: var(--accent); color: var(--accent-deep); background: var(--accent-soft); }

.pub-note { color: var(--muted); font-size: 14px; margin: 0 0 26px; }

/* ---------- timeline (research / experience) ---------- */
.timeline { border-left: 2px solid var(--border); margin-left: 8px; padding-left: 26px; }
.tl-item { position: relative; padding-bottom: 26px; }
.tl-item:last-child { padding-bottom: 0; }
.tl-item::before {
  content: ""; position: absolute; left: -34px; top: 6px;
  width: 11px; height: 11px; border-radius: 50%;
  background: #fff; border: 2px solid var(--accent);
}
.tl-date { font-family: "Cutive Mono", monospace; font-size: 12.5px; color: var(--accent-deep); }
.tl-role { font-weight: 700; margin: 2px 0 1px; font-size: 16.5px; }
.tl-org { color: var(--muted); font-size: 14.5px; margin: 0; }
.tl-loc { color: var(--muted-2); font-size: 13px; margin: 2px 0 0; }

/* ---------- talks ---------- */
.talk { padding: 16px 0; border-top: 1px solid var(--border); }
.talk:first-child { border-top: none; }
.talk-title { font-weight: 700; font-size: 16px; margin: 0 0 2px; }
.talk-meta { color: var(--muted); font-size: 14px; margin: 0; }
.talk-meta .date { font-family: "Cutive Mono", monospace; color: var(--accent-deep); font-size: 12.5px; }

/* ---------- footer ---------- */
.footer { text-align: center; padding: 40px 0 60px; color: var(--muted-2); font-size: 13px; font-family: "Cutive Mono", monospace; }
.footer a { color: var(--muted-2); text-decoration: underline; }

/* ---------- responsive ---------- */
@media (max-width: 760px) {
  .about-grid { grid-template-columns: 1fr; gap: 28px; }
  .profile { position: static; }
  .nav-links { display: none; }
  .pub { grid-template-columns: 110px 1fr; gap: 14px; }
  .pub-thumb { width: 110px; }
  .news-item { grid-template-columns: 78px 1fr; }
}