:root {
  --paper: #f8f7f2;
  --surface: #fffefa;
  --ink: #1b1d20;
  --muted: #65686d;
  --faint: #8b8d91;
  --line: #d9d8d2;
  --line-strong: #babbb8;
  --link: #1756a9;
  --link-hover: #0d3f83;
  --content: 1120px;
  --reading: 760px;
  --header-height: 62px;
  --serif: Charter, "Bitstream Charter", Georgia, serif;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
  scroll-snap-type: y mandatory;
}
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Charter, "Bitstream Charter", Georgia, serif;
  font-size: 16px;
  line-height: 1.68;
  text-rendering: optimizeLegibility;
}
img { display: block; max-width: 100%; }
figure { margin: 0; }
button { font: inherit; }
a {
  color: var(--link);
  text-decoration-thickness: 1px;
  text-underline-offset: .18em;
}
a:hover { color: var(--link-hover); }
:focus-visible { outline: 2px solid var(--link); outline-offset: 3px; }

.major-snap {
  scroll-margin-top: 0;
  scroll-snap-align: start;
  scroll-snap-stop: always;
}
.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 100;
  padding: 8px 12px;
  background: var(--ink);
  color: white;
  font-family: var(--sans);
  transform: translateY(-160%);
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--line);
  background: rgba(248, 247, 242, .96);
}
.header-inner,
.profile-section,
.research-archive,
.section-block,
.site-footer {
  width: min(calc(100% - 48px), var(--content));
  margin-inline: auto;
}
.header-inner {
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}
.wordmark,
.primary-nav,
.nav-toggle,
.profile-links,
.section-kicker,
.current-role,
.topic-index,
.topic-directory,
.record-meta,
.record-links,
.record-status,
.topic-contribution span,
.experience-period,
.experience-role,
.site-footer {
  font-family: var(--sans);
}
.wordmark {
  color: var(--ink);
  font-size: .91rem;
  font-weight: 650;
  letter-spacing: .012em;
  text-decoration: none;
}
.primary-nav { display: flex; align-items: center; gap: 25px; }
.primary-nav a {
  color: #474a4f;
  font-size: .82rem;
  text-decoration: none;
}
.primary-nav a:hover { color: var(--link); }
.nav-toggle {
  display: none;
  min-height: 40px;
  border: 0;
  background: transparent;
  color: var(--ink);
  font-size: .82rem;
  cursor: pointer;
}

.profile-section {
  min-height: 0;
  display: grid;
  grid-template-columns: minmax(0, 700px) 176px;
  justify-content: start;
  align-items: center;
  gap: 56px;
  padding-block: 64px 60px;
  border-bottom: 1px solid var(--line-strong);
}
.section-kicker {
  margin: 0 0 15px;
  color: var(--link);
  font-size: .7rem;
  font-weight: 650;
  letter-spacing: .11em;
  text-transform: uppercase;
}
.profile-copy h1 {
  margin: 0;
  font-family: var(--sans);
  font-size: clamp(2.5rem, 5vw, 3.6rem);
  font-weight: 620;
  letter-spacing: -.055em;
  line-height: 1;
}
.current-role {
  margin: 17px 0 0;
  color: #44474c;
  font-size: .86rem;
}
.positioning {
  max-width: 680px;
  margin: 25px 0 0;
  color: #33363a;
  font-size: clamp(1.02rem, 1.7vw, 1.18rem);
  line-height: 1.58;
}
.profile-links {
  display: flex;
  flex-wrap: wrap;
  gap: 13px 24px;
  margin-top: 30px;
}
.profile-links a { font-size: .83rem; }
.profile-portrait { align-self: center; }
.profile-portrait img {
  width: 176px;
  height: 200px;
  object-fit: cover;
  object-position: 50% 36%;
  border: 1px solid var(--line-strong);
}
.profile-portrait figcaption {
  margin-top: 8px;
  color: var(--faint);
  font-family: var(--sans);
  font-size: .66rem;
  line-height: 1.35;
}

.research-archive { padding-block: 72px 0; }
.archive-intro {
  max-width: var(--reading);
  padding-bottom: 48px;
}
.archive-intro h2,
.section-heading h2 {
  margin: 0;
  font-family: var(--sans);
  font-size: clamp(1.9rem, 4vw, 2.7rem);
  font-weight: 620;
  letter-spacing: -.035em;
  line-height: 1.12;
}
.archive-intro > p:last-child {
  max-width: 620px;
  margin: 18px 0 0;
  color: var(--muted);
}
.research-layout {
  display: grid;
  grid-template-columns: 180px minmax(0, var(--reading));
  justify-content: space-between;
  gap: 72px;
}
.topic-directory {
  position: sticky;
  top: calc(var(--header-height) + 24px);
  align-self: start;
  padding-bottom: 28px;
  color: var(--muted);
  font-size: .76rem;
  line-height: 1.38;
}
.topic-directory > p {
  margin: 0 0 13px;
  color: var(--ink);
  font-weight: 650;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.topic-directory nav {
  position: relative;
  display: grid;
  gap: 4px;
  padding-left: 16px;
  border-left: 1px solid var(--line);
}
.topic-directory a {
  min-height: 28px;
  display: flex;
  align-items: center;
  color: var(--muted);
  text-decoration: none;
}
.topic-directory a[aria-current="location"] { color: var(--link); }
.active-rule {
  --active-y: 0px;
  --active-height: 28px;
  position: absolute;
  top: 0;
  left: -1px;
  width: 2px;
  height: var(--active-height);
  background: var(--link);
  transform: translateY(var(--active-y));
  transition: transform .24s ease, height .24s ease;
}
.topic-stack { min-width: 0; }
.topic-section {
  padding-block: 64px 76px;
  border-top: 1px solid var(--line-strong);
}
.topic-section:first-child { padding-top: 36px; }
.topic-heading {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 18px;
  margin-bottom: 36px;
}
.topic-index {
  margin: 4px 0 0;
  color: var(--link);
  font-size: .7rem;
  font-weight: 650;
}
.topic-title-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 22px;
}
.topic-title-row h2 {
  margin: 0;
  font-family: var(--sans);
  font-size: clamp(1.45rem, 2.4vw, 1.9rem);
  font-weight: 620;
  letter-spacing: -.035em;
  line-height: 1.18;
}
.record-status {
  flex: 0 0 auto;
  color: var(--muted);
  font-size: .71rem;
  font-weight: 500;
  letter-spacing: .015em;
}
.topic-overview {
  margin: 17px 0 0;
  color: #35383c;
  font-size: 1.02rem;
}
.topic-contribution {
  margin: 20px 0 0;
  padding-left: 17px;
  border-left: 2px solid var(--link);
  color: #36393d;
}
.topic-contribution span {
  display: block;
  margin-bottom: 4px;
  color: var(--muted);
  font-size: .66rem;
  font-weight: 650;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.research-record {
  padding-block: 30px;
  border-top: 1px solid var(--line);
}
.research-record-heading {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: start;
}
.research-record-heading h3 {
  max-width: 680px;
  margin: 4px 0 0;
  font-size: 1.2rem;
  line-height: 1.38;
}
.record-label,
.experience-context { font-family: var(--sans); }
.record-label {
  margin: 0;
  color: var(--muted);
  font-size: .69rem;
  letter-spacing: .11em;
  text-transform: uppercase;
}
.research-record-overview {
  max-width: 760px;
  margin: 16px 0 0;
  color: #3f4247;
}

.publication-entry {
  display: grid;
  grid-template-columns: 205px minmax(0, 1fr);
  gap: 28px;
  padding-block: 34px;
  border-top: 1px solid var(--line);
}
.paper-figure img {
  width: 100%;
  height: 168px;
  padding: 5px;
  border: 1px solid var(--line);
  background: white;
  object-fit: contain;
}
.paper-figure figcaption,
.evidence-figure figcaption {
  margin-top: 7px;
  color: var(--faint);
  font-family: var(--sans);
  font-size: .64rem;
  line-height: 1.42;
}
.publication-copy h3 {
  margin: -3px 0 9px;
  font-size: 1.13rem;
  font-weight: 700;
  line-height: 1.38;
}
.authors {
  margin: 0;
  color: #45484d;
  font-size: .88rem;
  line-height: 1.55;
}
.authors strong { color: var(--ink); font-weight: 700; }
.record-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 12px;
  margin: 10px 0 0;
  color: var(--muted);
  font-size: .72rem;
}
.record-links {
  display: flex;
  gap: 15px;
  margin: 10px 0 0;
  font-size: .75rem;
}
.paper-explanation {
  margin: 17px 0 0;
  color: #3c3f43;
  font-size: .96rem;
}

.evidence-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px 22px;
  margin-top: 28px;
}
.evidence-figure img {
  width: 100%;
  height: 210px;
  padding: 7px;
  border: 1px solid var(--line);
  background: white;
  object-fit: contain;
}

.section-block {
  max-width: 960px;
  display: grid;
  grid-template-columns: 210px minmax(0, 1fr);
  gap: 56px;
  padding-block: 88px;
  border-top: 1px solid var(--line-strong);
}
.section-heading h2 { font-size: clamp(1.65rem, 3vw, 2.2rem); }
.experience-list {
  margin: 0;
  padding: 0;
  list-style: none;
}
.experience-row {
  display: grid;
  grid-template-columns: minmax(88px, .24fr) minmax(0, 1fr);
  gap: 20px;
  padding: 0 0 28px;
}
.experience-row + .experience-row {
  padding-top: 28px;
  border-top: 1px solid var(--line);
}
.experience-period {
  margin: 3px 0 0;
  color: var(--muted);
  font-size: .7rem;
}
.experience-row h3 {
  margin: 0;
  font-family: var(--sans);
  font-size: 1.02rem;
  font-weight: 650;
  line-height: 1.45;
}
.experience-organization {
  margin: 5px 0 0;
  font-family: var(--sans);
  font-size: .78rem;
}
.experience-organization a { color: var(--link); }
.experience-context {
  margin: 5px 0 8px;
  color: var(--muted);
  font-size: .74rem;
}
.experience-description {
  margin: 10px 0 0;
  color: #45484d;
  font-size: .94rem;
}
.interactive-layout { min-width: 0; }
.taogpt-intro > p {
  max-width: 580px;
  margin: 0;
  color: #45484d;
}
.prompt-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
}
.prompt-row button {
  min-height: 38px;
  padding: 7px 12px;
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--link);
  font-family: var(--sans);
  font-size: .75rem;
  cursor: pointer;
}
.prompt-row button:hover { border-color: var(--link); background: var(--surface); }
.chat-panel {
  margin-top: 28px;
  padding-block: 20px 16px;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
}
.chat-messages {
  max-height: min(46vh, 440px);
  min-height: 150px;
  overflow-y: auto;
  padding: 4px 12px 18px 0;
  overscroll-behavior: contain;
}
.message {
  max-width: 88%;
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
  color: #373a3e;
}
.message + .message { margin-top: 4px; }
.message p { margin: 0; white-space: pre-wrap; }
.message.user {
  margin-left: auto;
  color: var(--ink);
  text-align: right;
}
.message.user::before,
.message.assistant::before {
  display: block;
  margin-bottom: 3px;
  color: var(--faint);
  font-family: var(--sans);
  font-size: .64rem;
  letter-spacing: .07em;
  text-transform: uppercase;
}
.message.user::before { content: "You"; }
.message.assistant::before { content: "TaoGPT"; }
.chat-form { margin-top: 18px; }
.chat-form label {
  display: block;
  margin-bottom: 7px;
  color: var(--muted);
  font-family: var(--sans);
  font-size: .7rem;
  font-weight: 650;
  letter-spacing: .06em;
  text-transform: uppercase;
}
.chat-input-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: stretch;
}
.chat-input-row textarea {
  min-height: 86px;
  resize: vertical;
  padding: 11px 12px;
  border: 1px solid var(--line-strong);
  border-right: 0;
  border-radius: 0;
  background: var(--surface);
  color: var(--ink);
  font: inherit;
  line-height: 1.45;
}
.chat-input-row textarea:focus-visible {
  outline: 2px solid var(--link);
  outline-offset: -2px;
}
.chat-input-row button {
  min-width: 76px;
  border: 1px solid var(--ink);
  border-radius: 0;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--sans);
  font-size: .76rem;
  cursor: pointer;
}
.chat-input-row button:disabled { cursor: wait; opacity: .62; }
.chat-status {
  min-height: 1.4em;
  margin: 9px 0 0;
  color: var(--muted);
  font-family: var(--sans);
  font-size: .68rem;
}
.contact-section { padding-bottom: 100px; }
.contact-section > p { margin: 0; font-size: 1.08rem; }

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding-block: 24px 38px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: .68rem;
}
.site-footer p { margin: 0; }

@media (max-width: 900px) {
  .research-layout { grid-template-columns: 150px minmax(0, 1fr); gap: 40px; }
  .publication-entry { grid-template-columns: 180px minmax(0, 1fr); gap: 22px; }
  .paper-figure img { height: 150px; }
}

@media (max-width: 760px) {
  :root { --header-height: 58px; }
  .header-inner,
  .profile-section,
  .research-archive,
  .section-block,
  .site-footer { width: min(calc(100% - 32px), var(--content)); }
  .header-inner { min-height: var(--header-height); }
  .primary-nav {
    width: 100%;
    display: flex;
    flex-wrap: wrap;
    gap: 2px 16px;
    padding-bottom: 12px;
  }
  .primary-nav a {
    min-height: 44px;
    display: inline-flex;
    align-items: center;
  }
  .wordmark,
  .nav-toggle,
  .profile-links a,
  .record-links a,
  .contact-section a,
  .site-footer a {
    min-block-size: 44px;
    display: inline-flex;
    align-items: center;
  }
  .is-enhanced .nav-toggle { display: inline-flex; }
  .is-enhanced .header-inner { flex-wrap: wrap; }
  .is-enhanced .primary-nav { display: none; }
  .is-enhanced .primary-nav.is-open { display: flex; }

  .profile-section {
    min-height: 0;
    grid-template-columns: minmax(0, 1fr) 92px;
    align-items: start;
    gap: 20px;
    padding-block: 64px 60px;
  }
  .profile-copy h1 { font-size: clamp(2.6rem, 13vw, 3.7rem); }
  .current-role { font-size: .75rem; }
  .positioning { font-size: 1rem; }
  .profile-links { grid-column: 1 / -1; gap: 12px 20px; margin-top: 24px; }
  .profile-portrait img { width: 92px; height: 110px; }

  .research-archive { padding-top: 56px; }
  .archive-intro { padding-bottom: 30px; }
  .research-layout { display: block; }
  .topic-directory {
    position: static;
    margin-bottom: 14px;
    padding: 0 0 12px;
    overflow-x: auto;
    overscroll-behavior-inline: contain;
  }
  .topic-directory > p { margin-bottom: 7px; }
  .topic-directory nav {
    width: max-content;
    display: flex;
    gap: 18px;
    padding: 0;
    border-left: 0;
  }
  .topic-directory a { min-height: 44px; white-space: nowrap; }
  .active-rule { display: none; }
  .topic-section { padding-block: 48px 58px; }
  .topic-section:first-child { padding-top: 34px; }
  .topic-heading { grid-template-columns: 28px minmax(0, 1fr); gap: 9px; margin-bottom: 30px; }
  .topic-title-row { display: block; }
  .topic-title-row .record-status { display: block; margin-top: 7px; }
  .topic-overview { font-size: 1rem; }
  .topic-contribution { padding-left: 13px; font-size: .94rem; }
  .research-record { padding-block: 26px; }
  .research-record-heading { display: block; }
  .research-record-heading .record-status { display: block; margin-top: 7px; }

  .publication-entry {
    grid-template-columns: 106px minmax(0, 1fr);
    gap: 14px;
    padding-block: 28px;
  }
  .paper-figure img { height: 104px; padding: 3px; }
  .paper-figure figcaption { font-size: .57rem; line-height: 1.3; }
  .publication-copy h3 { font-size: 1.02rem; line-height: 1.34; }
  .authors { font-size: .79rem; }
  .record-meta { font-size: .66rem; }
  .paper-explanation {
    grid-column: 1 / -1;
    margin-top: 15px;
    font-size: .9rem;
  }
  .record-links { font-size: .71rem; }
  .evidence-grid { grid-template-columns: 1fr; gap: 24px; }
  .evidence-figure img { height: auto; max-height: 260px; }

  .section-block {
    display: block;
    padding-block: 66px;
  }
  .section-heading { margin-bottom: 34px; }
  .experience-row { grid-template-columns: 72px minmax(0, 1fr); gap: 14px; }
  .experience-row a {
    min-block-size: 44px;
    display: inline-flex;
    align-items: center;
  }
  .prompt-row button,
  .chat-input-row button {
    min-height: 44px;
  }
  .chat-input-row { grid-template-columns: minmax(0, 1fr); }
  .chat-input-row textarea { border-right: 1px solid var(--line-strong); }
  .chat-input-row button { min-height: 46px; }
  .contact-section { padding-bottom: 76px; }
}

@media (max-width: 430px) {
  .profile-section { grid-template-columns: minmax(0, 1fr) 82px; }
  .profile-portrait img { width: 82px; height: 98px; }
  .profile-portrait figcaption { display: none; }
  .publication-entry { grid-template-columns: 96px minmax(0, 1fr); }
  .paper-figure img { height: 94px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto !important; scroll-snap-type: none !important; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}