/*
 * Yeonkyoung So | personal research homepage
 * Visual basis: DESIGN-ollama.md. White canvas, 720px reading column,
 * Inter for Latin, Noto Sans KR/TC for Korean/Chinese, and restrained pills.
 * No branding, terminal mockups, section-color bands, or shadow effects.
 */
:root {
  --primary: #000000;
  --ink: #000000;
  --ink-deep: #090909;
  --charcoal: #525252;
  --body: #737373;
  --canvas: #ffffff;
  --surface-soft: #fafafa;
  --hairline: #e5e5e5;
  --hairline-strong: #d4d4d4;
  --on-primary: #ffffff;
  --focus-ring: rgba(59, 130, 246, 0.5);
  --font-heading: var(--font-body);
  --font-body: "Inter", "Noto Sans KR", ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Apple SD Gothic Neo", "Malgun Gothic", "Noto Sans CJK KR", sans-serif;
  --font-ko: "Noto Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", "Noto Sans CJK KR", sans-serif;
  --font-hanja: "Noto Sans TC", "Noto Sans CJK TC", "Noto Sans KR", sans-serif;
  --content-width: 720px;
  --section-space: 88px;
  --page-gutter: 24px;
  --nav-height: 56px;
  --pill: 9999px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body {
  margin: 0;
  background: var(--canvas);
  color: var(--body);
  font-family: var(--font-body);
  font-optical-sizing: auto;
  font-style: normal;
  font-size: 16px;
  line-height: 1.5;
  font-weight: 400;
  letter-spacing: 0;
  -webkit-font-smoothing: antialiased;
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
}
/* Explicit language tags prevent TC from overriding Korean or Inter text. */
[lang="ko"] { font-family: var(--font-ko); font-optical-sizing: auto; }
[lang="zh-Hant"] { font-family: var(--font-hanja); font-optical-sizing: auto; }
[hidden] { display: none !important; }
p, h1, h2, h3, ul { margin: 0; }
a { color: var(--ink); text-underline-offset: 3px; text-decoration-thickness: 1px; }
a, button { -webkit-tap-highlight-color: transparent; }
button { font: inherit; cursor: pointer; }
img { display: block; max-width: 100%; }
strong { font-weight: 600; color: var(--ink); }
h1, h2 { color: var(--ink); font-family: var(--font-heading); letter-spacing: 0; }
h1 { font-size: 36px; font-weight: 500; line-height: 1.11; }
h2 { font-size: 24px; font-weight: 600; line-height: 1.33; }
h3 { font-family: var(--font-body); color: var(--ink); font-size: 18px; font-weight: 500; line-height: 1.5; }
sup { vertical-align: super; font-size: .75em; line-height: 0; }
:focus-visible { outline: 3px solid var(--focus-ring); outline-offset: 4px; }
main:focus, section[tabindex="-1"]:focus { outline: none; }
.container { width: min(var(--content-width), calc(100% - var(--page-gutter) * 2)); margin-inline: auto; }
.section { margin-top: var(--section-space); }
.icon { width: 14px; height: 14px; flex: 0 0 auto; }
.skip-link { position: fixed; top: 8px; left: 8px; z-index: 100; padding: 10px 20px; border-radius: var(--pill); color: var(--on-primary); background: var(--primary); transform: translateY(-180%); text-decoration: none; }
.skip-link:focus { transform: translateY(0); }

/* White, text-only utility navigation. No personal name rendered as a logo. */
.site-header { position: relative; z-index: 10; background: var(--canvas); }
.nav-inner { min-height: var(--nav-height); display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.site-name { display: inline-flex; align-items: center; min-height: 44px; font-size: 14px; font-weight: 500; white-space: nowrap; text-decoration: none; border-radius: var(--pill); }
.primary-nav { display: flex; align-items: center; gap: 24px; }
.primary-nav a { display: inline-flex; align-items: center; min-height: 44px; font-size: 14px; font-weight: 500; text-decoration: none; border-radius: var(--pill); }
.menu-toggle { display: none; }

/* Center-aligned introduction, with the existing repository photo kept small. */
.hero { padding-top: 56px; }
.hero-stack { display: flex; flex-direction: column; align-items: center; gap: 24px; }
.portrait { position: relative; width: 112px; height: 112px; border-radius: 50%; overflow: hidden; background: var(--surface-soft); flex: 0 0 auto; }
.portrait img { width: 100%; height: 100%; object-fit: cover; object-position: center; }
.photo-fallback { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 4px; padding: 12px; text-align: center; color: var(--body); font-size: 12px; line-height: 1.4; }
.photo-fallback span { font-size: 10px; }
.hero-copy { text-align: center; max-width: 640px; width: 100%; }
.korean-name { margin-top: 8px; font-size: 16px; color: var(--charcoal); }
.role { margin-top: 20px; font-size: 16px; font-weight: 500; color: var(--ink); }
.affiliation { margin-top: 6px; font-size: 14px; line-height: 1.6; }
.hero-bio { max-width: 592px; margin: 24px auto 0; font-size: 16px; line-height: 1.5; text-wrap: pretty; }
.profile-links { margin-top: 24px; display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; }
.button { min-height: 36px; display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 8px 20px; border-radius: var(--pill); border: 1px solid transparent; font-size: 14px; font-weight: 500; line-height: 1.25; text-decoration: none; }
.button-primary { color: var(--on-primary); background: var(--primary); }
.button-primary:active { background: var(--ink-deep); }
.button-secondary { color: var(--ink); background: var(--canvas); border-color: var(--hairline-strong); }
.button-secondary:active { background: var(--surface-soft); }

/* The research section stays on the same white canvas, in the same column. */
.research-topics { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.research-topics li { color: var(--charcoal); background: var(--surface-soft); padding: 6px 12px; border-radius: var(--pill); font-size: 14px; line-height: 1.43; }
.research-copy { margin-top: 20px; }
.research-copy p { font-size: 16px; line-height: 1.5; }
.research-copy .broader-interest { margin-top: 12px; }

/* A bibliography, not marketing cards. Dividers are limited to list rows. */
.section-heading { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.text-link { display: inline-flex; align-items: center; gap: 4px; min-height: 36px; font-size: 14px; line-height: 1.43; border-radius: var(--pill); }
.section-heading .text-link { white-space: nowrap; }
.publication-key { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-top: 24px; }
.year { color: var(--charcoal); font-size: 14px; font-weight: 500; font-variant-numeric: tabular-nums; }
.publication-key p { font-size: 12px; line-height: 1.33; }
.publication { padding-block: 28px; border-bottom: 1px solid var(--hairline); }
.publication:first-child { padding-top: 24px; }
.publication:last-child { border-bottom: 0; padding-bottom: 0; }
.publication-meta { display: flex; align-items: center; flex-wrap: wrap; gap: 6px 10px; margin-bottom: 8px; }
.venue { color: var(--charcoal); font-size: 12px; font-weight: 500; line-height: 1.6; }
.paper-status { background: var(--surface-soft); color: var(--charcoal); border: 1px solid var(--hairline); border-radius: var(--pill); padding: 2px 8px; font-size: 12px; line-height: 1.4; }
.publication h3 { text-wrap: pretty; overflow-wrap: break-word; }
.authors { margin-top: 8px; font-size: 14px; line-height: 1.55; }
.publication-description { margin-top: 10px; font-size: 16px; line-height: 1.5; }
.paper-links { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.paper-links a { display: inline-flex; align-items: center; justify-content: center; padding: 8px 16px; min-height: 36px; color: var(--ink); background: var(--canvas); border: 1px solid var(--hairline-strong); border-radius: var(--pill); text-decoration: none; font-size: 14px; font-weight: 500; line-height: 1.25; }
.paper-links a:active { background: var(--surface-soft); }

/* Education retains the exact degree dates and owner-corrected thesis title. */
.education-list { display: grid; gap: 28px; margin-top: 24px; }
.education-entry { display: grid; grid-template-columns: 176px minmax(0, 1fr); gap: 24px; }
.dates { padding-top: 3px; color: var(--body); font-size: 14px; line-height: 1.5; font-variant-numeric: tabular-nums; }
.degree-heading { display: flex; align-items: center; flex-wrap: wrap; gap: 4px 12px; }
.degree-status { color: var(--body); font-size: 12px; line-height: 1.4; }
.institution { margin-top: 4px; font-size: 14px; line-height: 1.5; }
.thesis { margin-top: 12px; font-size: 14px; line-height: 1.55; }
.detail-label { display: block; margin-bottom: 3px; color: var(--charcoal); font-weight: 500; font-size: 12px; }
.thesis cite { font-style: normal; }
.education-detail { margin-top: 8px; font-size: 14px; }


/* Thesis details remain within Education; no separate content page is required. */
.thesis-description {
  margin-top: 8px;
  color: var(--charcoal);
  font-size: 13px;
  line-height: 1.75;
  overflow-wrap: break-word;
}
.thesis-details { margin-top: 8px; }
.thesis-details > summary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  max-width: 100%;
  min-height: 44px;
  margin-left: -12px;
  padding: 8px 12px;
  border-radius: var(--pill);
  color: var(--charcoal);
  font-size: 13px;
  font-weight: 500;
  line-height: 1.5;
  cursor: pointer;
  list-style: none;
}
.thesis-details > summary::-webkit-details-marker { display: none; }
.thesis-details > summary::marker { content: ""; }
.thesis-details > summary:active { background: var(--surface-soft); }
.thesis-details[open] > summary .details-chevron { transform: rotate(180deg); }
.thesis-details-copy {
  display: grid;
  gap: 8px;
  padding: 6px 0 0;
  color: var(--charcoal);
  font-size: 13px;
  line-height: 1.75;
  overflow-wrap: break-word;
}
.thesis-work-title { font-size: 14px; color: var(--ink); }
.thesis-work-title cite { font-style: normal; }
.thesis-details-copy .thesis-language { color: var(--body); font-size: 12px; }

/* Selected awards stay concise; certifications are supporting detail, closed by default. */
.awards-list { display: grid; gap: 24px; margin-top: 24px; }
/* Korean and its English translation form one award, not two entries. */
.award-entry { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); align-items: start; gap: 12px 32px; min-width: 0; break-inside: avoid; }
.award-copy { min-width: 0; }
.award-prize { color: var(--charcoal); font-size: 12px; font-weight: 500; line-height: 1.6; margin-bottom: 5px; }
.award-entry h3, .award-title-en { font-size: 16px; font-weight: 500; line-height: 1.5; overflow-wrap: break-word; text-wrap: pretty; }
.award-copy[lang="ko"] h3 { font-family: var(--font-ko); word-break: keep-all; }
.award-title-en { color: var(--charcoal); }
@media (max-width: 640px) {
  .award-entry { grid-template-columns: minmax(0, 1fr); gap: 12px; }
}
.certifications { margin-top: 24px; }
.certifications > summary { display: inline-flex; align-items: center; gap: 8px; max-width: 100%; min-height: 44px; margin-left: -12px; padding: 8px 12px; border-radius: var(--pill); color: var(--charcoal); font-size: 14px; font-weight: 500; line-height: 1.5; cursor: pointer; list-style: none; }
.certifications > summary::-webkit-details-marker { display: none; }
.certifications > summary::marker { content: ""; }
.certifications > summary:active { background: var(--surface-soft); }
.certifications[open] > summary .details-chevron { transform: rotate(180deg); }
.certification-list { display: grid; gap: 12px; padding: 12px 0 0; list-style: none; }
.certification-list li { display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px 12px; font-size: 14px; line-height: 1.7; }
.certification-name { color: var(--charcoal); font-weight: 500; }
.certification-detail { color: var(--body); font-size: 13px; word-break: keep-all; }
/* Keep six section links on one line inside the existing 720px column. */
@media (min-width: 768px) {
  .primary-nav { gap: 18px; }
  .nav-inner { gap: 16px; }
}

/* A small personal corner on the same white page. No large slogan or autoplay. */
.personal-section h2 { font-size: 20px; font-weight: 500; }
.favorite-quote, .collected-quote { margin: 0; }
.favorite-quote { margin-top: 24px; }
.hanja-quote { margin: 0; color: var(--ink); font-size: 26px; font-weight: 500; line-height: 1.6; letter-spacing: .14em; }
.quote-meta { margin-top: 8px; color: var(--body); font-size: 12px; line-height: 1.7; }
.quote-meta cite, .collected-quote cite { font-style: normal; }
.quote-meta a, .collected-quote figcaption a { color: var(--body); text-decoration-color: var(--hairline-strong); }
.quote-gloss { margin-top: 7px; color: var(--charcoal); font-size: 14px; line-height: 1.8; word-break: keep-all; overflow-wrap: break-word; }
.more-quotes { margin-top: 12px; }
.more-quotes > summary { display: inline-flex; align-items: center; gap: 8px; min-height: 44px; padding: 8px 12px; margin-left: -12px; border-radius: var(--pill); color: var(--charcoal); font-size: 13px; line-height: 1.5; cursor: pointer; list-style: none; }
.more-quotes > summary::-webkit-details-marker { display: none; }
.more-quotes > summary::marker { content: ""; }
.more-quotes > summary:active { background: var(--surface-soft); }
.details-chevron { width: 14px; height: 14px; flex: 0 0 auto; }
.more-quotes[open] .details-chevron { transform: rotate(180deg); }
.quote-collection { display: grid; gap: 24px; padding: 12px 0 8px; }
.collected-quote blockquote { margin: 0; color: var(--charcoal); font-size: 15px; line-height: 1.7; overflow-wrap: break-word; }
.collected-quote blockquote[lang="ko"] { word-break: keep-all; }
.collected-quote figcaption { margin-top: 6px; color: var(--body); font-size: 12px; line-height: 1.7; }
.quote-location { display: block; margin-top: 2px; }
.bgm-strip { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 20px 24px; margin-top: 28px; padding: 20px; border: 1px solid var(--hairline); border-radius: 12px; background: var(--surface-soft); }
.bgm-copy { min-width: 0; }
.bgm-label { color: var(--body); font-size: 11px; font-weight: 500; letter-spacing: .12em; line-height: 1.5; }
.track-title { margin-top: 6px; color: var(--ink); font-size: 16px; font-weight: 500; line-height: 1.5; overflow-wrap: break-word; }
.track-artist { color: var(--body); font-size: 13px; font-weight: 400; white-space: nowrap; }
.track-note { margin-top: 4px; color: var(--body); font-size: 13px; line-height: 1.6; }
.bgm-link { flex-shrink: 0; min-height: 44px; padding-inline: 14px; font-size: 13px; }
.play-icon { width: 13px; height: 13px; flex: 0 0 auto; }

/* Optional personal details, collapsed until the reader chooses to open them. */
.personal-facts { margin-top: 24px; }
.personal-facts > summary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  max-width: 100%;
  min-height: 44px;
  margin-left: -12px;
  padding: 8px 12px;
  border-radius: var(--pill);
  color: var(--charcoal);
  font-size: 14px;
  font-weight: 500;
  line-height: 1.5;
  cursor: pointer;
  list-style: none;
}
.personal-facts > summary::-webkit-details-marker { display: none; }
.personal-facts > summary::marker { content: ""; }
.personal-facts > summary:active { background: var(--surface-soft); }
.personal-facts[open] > summary .details-chevron { transform: rotate(180deg); }
.personal-facts-copy {
  display: grid;
  gap: 14px;
  padding-top: 12px;
  color: var(--charcoal);
  font-size: 14px;
  line-height: 1.75;
  overflow-wrap: break-word;
}

.site-footer { margin-top: var(--section-space); }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding-block: 24px 32px; border-top: 1px solid var(--hairline); font-size: 12px; line-height: 1.5; }
.footer-inner > div { display: flex; flex-wrap: wrap; align-items: center; column-gap: 20px; row-gap: 4px; }
.footer-inner a { display: inline-flex; align-items: center; min-height: 36px; border-radius: var(--pill); }
.footer-inner > div a { color: var(--body); }
.back-to-top { gap: 4px; white-space: nowrap; }
.back-to-top .icon { width: 12px; height: 12px; }

@media (max-width: 850px) {
  :root { --section-space: 64px; }
}
@media (max-width: 767px) {
  .nav-inner { flex-wrap: wrap; gap: 0 16px; }
  .primary-nav { flex-wrap: wrap; gap: 0 20px; }
  .nav-enhanced .menu-toggle { display: inline-flex; align-items: center; justify-content: center; gap: 10px; min-height: 36px; padding: 8px 14px; border-radius: var(--pill); border: 1px solid var(--hairline-strong); color: var(--ink); background: var(--canvas); font-size: 14px; font-weight: 500; }
  .menu-lines { display: flex; flex-direction: column; gap: 4px; width: 14px; }
  .menu-lines span { display: block; width: 14px; height: 1px; background: currentColor; }
  .menu-toggle[aria-expanded="true"] .menu-lines span:first-child { transform: translateY(2.5px) rotate(45deg); }
  .menu-toggle[aria-expanded="true"] .menu-lines span:last-child { transform: translateY(-2.5px) rotate(-45deg); }
  .nav-enhanced .primary-nav { display: none; width: 100%; padding-block: 8px 16px; flex-direction: column; align-items: stretch; gap: 4px; }
  .nav-enhanced .primary-nav.is-open { display: flex; }
  .nav-enhanced .primary-nav a { padding-inline: 14px; min-height: 44px; }
}
@media (max-width: 640px) {
  .hanja-quote { font-size: 24px; }
  .bgm-strip { padding: 18px; gap: 16px; }
  .track-artist { display: block; margin-top: 2px; }
  .artist-divider { display: none; }
  :root { --section-space: 48px; }
  .hero { padding-top: 32px; }
  .hero-stack { gap: 20px; }
  h1 { font-size: 28px; line-height: 1.15; }
  .role { margin-top: 16px; }
  .hero-bio { margin-top: 20px; }
  .profile-links { margin-top: 20px; }
  .button, .paper-links a { min-height: 44px; }
  .research-topics { gap: 6px; }
  .research-topics li { font-size: 12px; }
  .section-heading { align-items: flex-start; flex-direction: column; gap: 4px; }
  .publication-key { margin-top: 20px; }
  .publication { padding-block: 24px; }
  .publication:first-child { padding-top: 20px; }
  .education-entry { grid-template-columns: 1fr; gap: 6px; }
  .dates { padding-top: 0; font-size: 12px; }
  .education-list { gap: 24px; }
  .footer-inner { align-items: flex-start; }
  .footer-inner > div { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 360px) {
  :root { --page-gutter: 20px; }
  .button { padding-inline: 15px; font-size: 13px; }
  .profile-links { gap: 6px; }
  .primary-nav a { font-size: 13px; }
  .research-topics li { padding-inline: 10px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}
@media print {
  body { color: #000; font-size: 10pt; }
  .site-header, .skip-link, .back-to-top { display: none !important; }
  .container { width: 100%; }
  .hero { padding-top: 0; }
  .portrait { width: 72pt; height: 72pt; }
  h1 { font-size: 24pt; }
  h2 { font-size: 16pt; }
  h3 { font-size: 12pt; }
  .section, .site-footer { margin-top: 24pt; }
  .hero-bio, .research-copy p, .publication-description { font-size: 10pt; }
  .publication, .education-entry { break-inside: avoid; }
  .publication { padding-block: 14pt; }
  .button, .paper-links a { min-height: 0; padding: 4pt 8pt; background: none; color: #000; border-color: #d4d4d4; }
  .education-entry { grid-template-columns: 120pt minmax(0, 1fr); }
  .research-topics li, .paper-status { background: none; }
}