/* Cyber Law and Policy Lab, Korea University */

:root {
  --paper: #ffffff;
  --ink: #222222;
  --muted: #62626a;
  --rule: #e3e3e6;
  --crimson: #862633;      /* KU crimson (PANTONE 202 C) */
  --crimson-wash: #f7f0f1;
  --crimson-deep: #6e1d29;
  --tint: #f3f4f6;         /* cool grey band, not cream */

  --font: "IBM Plex Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  --wrap: 1080px;
  --label: 200px;          /* left column for section headings */
  --header-h: 64px;
}

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

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 16px); -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.75 var(--font);
  word-break: keep-all;
  overflow-wrap: break-word;
  -webkit-font-smoothing: antialiased;
}
body.menu-open { overflow: hidden; }

h1, h2, h3, p, dl, dd, ol, ul { margin: 0; }
ol, ul { padding: 0; list-style: none; }
img { display: block; max-width: 100%; height: auto; }

a { color: inherit; text-decoration: underline; text-decoration-color: var(--rule); text-underline-offset: 3px; text-decoration-thickness: 1px; }
a:hover { color: var(--crimson); text-decoration-color: currentColor; }
:focus-visible { outline: 2px solid var(--crimson); outline-offset: 2px; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.muted { color: var(--muted); }

.skip-link { position: absolute; left: 16px; top: -100px; z-index: 100; padding: 6px 12px; background: var(--ink); color: #fff; }
.skip-link:focus { top: 12px; }

/* Header ----------------------------------------------------------------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  height: var(--header-h);
  background: var(--paper);
  border-bottom: 1px solid var(--rule);
}
.header-inner { height: 100%; display: flex; align-items: center; gap: 32px; }

.brand { display: flex; align-items: center; gap: 10px; min-width: 0; font-weight: 600; font-size: 16px; text-decoration: none; color: var(--ink); }
.brand:hover { color: var(--ink); }
.brand img { width: 32px; flex: none; }
.brand-text { display: flex; flex-direction: column; min-width: 0; }
.brand-affil { font-size: 14px; font-weight: 500; line-height: 1.25; color: #4a4a52; overflow: hidden; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.brand-name { font-size: 17px; line-height: 1.35; }

.nav { display: flex; gap: 24px; margin-left: auto; }
.nav a { font-size: 16px; color: var(--muted); text-decoration: none; }
.nav a:hover, .nav a.active { color: var(--ink); }
.nav a.active { box-shadow: inset 0 -2px 0 var(--crimson); }

.lang-toggle {
  padding: 0; border: 0; background: none; cursor: pointer;
  font: 500 15px var(--font); color: var(--muted);
}
.lang-toggle:hover { color: var(--crimson); }

.menu-toggle { display: none; width: 40px; height: 40px; margin-right: -8px; padding: 0; border: 0; background: none; cursor: pointer; }
.menu-toggle span { display: block; width: 20px; height: 1.5px; margin: 5px auto; background: var(--ink); transition: transform .2s; }
.menu-toggle[aria-expanded="true"] span:first-child { transform: translateY(3.25px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] span:last-child { transform: translateY(-3.25px) rotate(-45deg); }

/* Intro ------------------------------------------------------------------ */
.intro { padding: 104px 0 96px; background: var(--crimson); color: #fff; }
.intro a { color: #fff; }
.intro-affil { font-size: 17px; color: rgba(255, 255, 255, .78); }
.intro-title {
  margin-top: 12px;
  font-size: clamp(44px, 8.4vw, 104px);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.035em;
}
.intro-en { margin-top: 10px; font-size: clamp(18px, 2.2vw, 23px); color: rgba(255, 255, 255, .78); }
.intro-lead { color: rgba(255, 255, 255, .94); }
html[lang="en"] .intro-en,
html[lang="en"] .prof-name-en { display: none; }
.intro-lead { margin-top: 40px; max-width: 34em; font-size: 20px; line-height: 1.8; }

/* Section rows: heading left, content right ------------------------------- */
.row-tint { background: var(--tint); }
.row:not(.row-tint) + .row:not(.row-tint) { border-top: 1px solid var(--rule); }
.row-inner { display: grid; grid-template-columns: var(--label) minmax(0, 1fr); gap: 32px; padding-top: 80px; padding-bottom: 88px; }
.row h2 { font-size: 24px; font-weight: 600; line-height: 1.4; letter-spacing: -0.01em; }
.row-body { max-width: 760px; }
.row-note { margin-bottom: 28px; color: var(--muted); }

.prose p + p { margin-top: 1em; }

/* Research --------------------------------------------------------------- */
.research-list {
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px;
  background: var(--rule); border: 1px solid var(--rule);
}
.research-list > div { padding: 24px 26px 26px; background: var(--paper); }
.research-list dt { font-size: 18px; font-weight: 600; }
.research-list dd { margin-top: 6px; color: var(--muted); font-size: 16px; line-height: 1.65; }

/* Facts (definition rows) -------------------------------------------------- */
.facts > div { display: grid; grid-template-columns: 88px minmax(0, 1fr); gap: 16px; padding: 10px 0; border-bottom: 1px solid var(--rule); }
.facts > div:first-child { border-top: 1px solid var(--rule); }
.facts dt { color: var(--muted); }

/* Professor ------------------------------------------------------------- */
.prof { display: grid; grid-template-columns: 208px minmax(0, 1fr); gap: 40px; align-items: start; }
.prof-photo { width: 208px; aspect-ratio: 249 / 376; object-fit: cover; background: #eee; }
.prof-name { font-size: 32px; font-weight: 600; line-height: 1.3; letter-spacing: -0.01em; }
.prof-name-en { margin-left: 6px; font-size: 17px; font-weight: 400; color: var(--muted); }
.prof-role { margin: 8px 0 24px; color: var(--muted); }

/* Research trends ------------------------------------------------------- */
.sub-title { margin: 44px 0 16px; font-size: 18px; font-weight: 600; }
.row-note + .sub-title, .row-body > .sub-title:first-child { margin-top: 0; }
.heat-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.heat { width: 100%; min-width: 560px; border-collapse: separate; border-spacing: 2px; font-size: 15px; font-variant-numeric: tabular-nums; }
.heat th, .heat td { padding: 8px 10px; font-weight: 400; }
.heat thead th { font-size: 14px; color: var(--muted); text-align: center; white-space: nowrap; }
.heat thead th:first-child, .heat tbody th, .heat tfoot th { text-align: left; }
.heat tbody th { white-space: nowrap; }
.heat td { width: 13%; text-align: center; }
.heat .h0 { background: #f6f6f7; color: #a2a2aa; }
.heat .h1 { background: #f4e4e7; }
.heat .h2 { background: #e6bec5; }
.heat .h3 { background: #c97c88; }
.heat .h4 { background: var(--crimson); color: #fff; }
.heat .heat-sum { font-weight: 600; }
.heat tfoot th, .heat tfoot td { border-top: 1px solid var(--ink); color: var(--muted); }
.heat tfoot .heat-sum { color: var(--ink); }

.net { position: relative; border: 1px solid var(--rule); background: var(--paper); }
.net canvas { display: block; cursor: grab; }
.net canvas:active { cursor: grabbing; }
.net-zoom { position: absolute; right: 10px; top: 10px; display: flex; gap: 4px; }
.net-zoom button {
  min-width: 32px; height: 32px; padding: 0 8px; border: 1px solid var(--rule); border-radius: 2px;
  background: rgba(255, 255, 255, .92); cursor: pointer; font: 500 15px var(--font); color: var(--ink);
}
.net-zoom button:hover { border-color: var(--crimson); color: var(--crimson); }
.net-foot { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 8px 32px; margin-top: 12px; align-items: start; }
.net-legend { display: flex; flex-wrap: wrap; gap: 4px 16px; font-size: 14px; color: var(--muted); white-space: nowrap; }
.net-dot { display: inline-block; width: 10px; height: 10px; margin-right: 6px; border-radius: 50%; vertical-align: 0; }
.net-info { min-height: 72px; font-size: 15px; }
.net-hint, .net-kind, .net-meta { color: var(--muted); }
.net-kind { font-size: 14px; }
.net-name { font-weight: 600; line-height: 1.5; }
.net-name a { text-decoration: none; }
.net-name a:hover { text-decoration: underline; }
.net-meta { margin-top: 2px; font-size: 14px; line-height: 1.6; }
.net-info .text-button { margin-top: 6px; font-size: 15px; }

.kw-help { margin-bottom: 14px; font-size: 15px; color: var(--muted); }
.kw-list { display: flex; flex-wrap: wrap; gap: 8px; }
.kw {
  padding: 5px 12px; border: 1px solid var(--rule); border-radius: 999px; background: var(--paper); cursor: pointer;
  font: 400 15px/1.4 var(--font); color: var(--ink);
}
.kw:hover { border-color: var(--crimson); color: var(--crimson); }
.kw .count { margin-left: 6px; font-size: 13px; color: var(--muted); }

/* Members --------------------------------------------------------------- */
.member-group + .member-group { margin-top: 32px; }
.member-group h3 { margin-bottom: 12px; font-size: 16px; font-weight: 600; color: var(--muted); }
.member-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 12px 32px; }
.member-list span { display: block; color: var(--muted); font-size: 15px; }
.empty { color: var(--muted); }

/* Publications ---------------------------------------------------------- */
.pub-tools { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px 24px; padding-bottom: 16px; border-bottom: 1px solid var(--ink); }
.pub-tools[hidden] { display: none; }
.pub-tabs { display: flex; flex-wrap: wrap; gap: 4px 20px; }
.pub-tabs button {
  padding: 4px 0; border: 0; background: none; cursor: pointer;
  font: 400 16px var(--font); color: var(--muted);
}
.pub-tabs button:hover { color: var(--ink); }
.pub-tabs button[aria-selected="true"] { color: var(--ink); font-weight: 600; box-shadow: inset 0 -2px 0 var(--crimson); }
.pub-tabs .count { margin-left: 4px; font-size: 14px; font-weight: 400; color: var(--muted); }
.pub-search {
  width: 260px; max-width: 100%; height: 40px; padding: 0 12px;
  border: 1px solid var(--rule); border-radius: 2px; background: var(--paper);
  font: 400 15px var(--font); color: var(--ink);
}
.pub-search:focus { outline: none; border-color: var(--ink); }

.pub-year { display: grid; grid-template-columns: 68px minmax(0, 1fr); gap: 16px; padding: 20px 0; border-bottom: 1px solid var(--rule); }
.pub-year h3 { font-size: 16px; font-weight: 600; line-height: 1.6; color: var(--crimson); }
.pub-year li + li { margin-top: 16px; }
.pub-title { font-weight: 500; line-height: 1.6; }
.pub-title a { text-decoration: none; }
.pub-title a:hover { text-decoration: underline; }
.pub-meta { margin-top: 2px; font-size: 15px; line-height: 1.6; color: var(--muted); }

.text-button {
  margin-top: 20px; padding: 0; border: 0; background: none; cursor: pointer;
  font: 500 16px var(--font); color: var(--crimson);
  text-decoration: underline; text-underline-offset: 3px;
}
.text-button[hidden] { display: none; }

/* Video ------------------------------------------------------------------ */
.video-frame { position: relative; aspect-ratio: 16 / 9; background: #000; }
.video-frame iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.yt-facade { position: absolute; inset: 0; width: 100%; height: 100%; padding: 0; border: 0; background: #000; cursor: pointer; }
.yt-facade img { width: 100%; height: 100%; object-fit: cover; }
.yt-play {
  position: absolute; left: 50%; top: 50%; width: 64px; height: 64px; margin: -32px 0 0 -32px;
  border-radius: 50%; background: var(--crimson);
}
.yt-play::after {
  content: ""; position: absolute; left: 26px; top: 21px;
  border-style: solid; border-width: 11px 0 11px 17px; border-color: transparent transparent transparent #fff;
}
.yt-facade:hover .yt-play { background: #6e1d29; }
.video-caption { margin-top: 12px; font-size: 15px; color: var(--muted); }

/* Footer ----------------------------------------------------------------- */
.site-footer { background: var(--tint); border-top: 1px solid var(--rule); padding: 40px 0 48px; font-size: 15px; }
.footer-inner { display: flex; flex-wrap: wrap; align-items: center; gap: 24px 32px; }
.footer-logo img { width: 144px; }
.footer-text { line-height: 1.6; }
.footer-links { display: flex; gap: 20px; margin-left: auto; }
.footer-links a { color: var(--muted); text-decoration: none; }
.footer-links a:hover { color: var(--crimson); }

/* Responsive ------------------------------------------------------------- */
@media (max-width: 900px) {
  .menu-toggle { display: block; }
  .header-inner { gap: 16px; }
  .lang-toggle { margin-left: auto; }
  .nav {
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; gap: 0; margin: 0; padding: 8px 24px 24px;
    background: var(--paper); border-bottom: 1px solid var(--rule);
    display: none;
  }
  .nav.open { display: flex; }
  .nav a { padding: 12px 0; font-size: 18px; color: var(--ink); border-bottom: 1px solid var(--rule); }
  .nav a.active { box-shadow: none; color: var(--crimson); }

  .row-inner { grid-template-columns: minmax(0, 1fr); gap: 24px; padding-top: 56px; padding-bottom: 64px; }
}

@media (max-width: 600px) {
  .wrap { padding-left: 16px; padding-right: 16px; }
  .nav { padding: 8px 16px 20px; }
  .header-inner { gap: 12px; }
  .brand { gap: 8px; }
  .brand img { width: 28px; }
  .brand-affil { font-size: 12.5px; }
  .brand-name { font-size: 16px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .intro { padding: 72px 0 64px; }
  .intro-lead { margin-top: 28px; font-size: 18px; }
  .research-list { grid-template-columns: minmax(0, 1fr); }
  .research-list > div { padding: 20px; }
  .prof { grid-template-columns: minmax(0, 1fr); gap: 20px; }
  .prof-photo { width: 160px; }
  .pub-search { width: 100%; }
  .pub-year { grid-template-columns: minmax(0, 1fr); gap: 8px; }
  .facts > div { grid-template-columns: 72px minmax(0, 1fr); }
  .net-foot { grid-template-columns: minmax(0, 1fr); }
  .heat { min-width: 0; font-size: 14px; }
  .heat th, .heat td { padding: 7px 4px; }
  .heat thead th { font-size: 12.5px; white-space: normal; line-height: 1.3; }
  .heat tbody th { white-space: normal; padding-left: 0; font-size: 13.5px; line-height: 1.35; }
  .heat td { width: 15%; }
  .footer-links { margin-left: 0; }
}

@media (max-width: 360px) {
  .header-inner { gap: 8px; }
  .brand { gap: 6px; }
  .brand img { width: 24px; }
  .brand-affil { font-size: 12px; }
  .brand-name { font-size: 14.5px; letter-spacing: -0.01em; }
  .lang-toggle { font-size: 14px; }
  .menu-toggle { width: 36px; margin-right: -6px; }
}

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