@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+KR:wght@300;400;700&family=JetBrains+Mono:ital,wght@0,300;0,400;0,600;1,300&family=Noto+Sans+KR:wght@300;400;500&display=swap');

/* ═══════════════════════════════════════════════
   DESIGN TOKENS
   墨(Ink) · 朱(Vermillion) · 金(Gold)
═══════════════════════════════════════════════ */
:root {
  --ink:         #0c0c0e;
  --ink-soft:    #131316;
  --ink-panel:   #18181c;
  --ink-card:    #1e1e24;
  --border:      #252530;
  --border-soft: #1e1e28;
  --vermillion:  #b83228;
  --vred:        #9a2820;
  --vglow:       rgba(184,50,40,0.12);
  --gold:        #c4923c;
  --gold-soft:   rgba(196,146,60,0.1);
  --text:        #e4e4ee;
  --text-soft:   #9898aa;
  --text-mute:   #5a5a6a;
  --mono: 'JetBrains Mono', 'Courier New', monospace;
  --serif: 'Noto Serif KR', 'Georgia', serif;
  --sans: 'Noto Sans KR', sans-serif;
  --nav-h: 52px;
  --left-w: 260px;
}

/* ═══ RESET ═══ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 15px; scroll-behavior: smooth; }
body {
  background: var(--ink);
  color: var(--text);
  font-family: var(--sans);
  font-weight: 300;
  line-height: 1.75;
  min-height: 100vh;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ═══════════════════════════════════════════════
   TOP NAV
═══════════════════════════════════════════════ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  background: rgba(12,12,14,0.93);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 2rem;
  gap: 0;
  z-index: 200;
}

.nav::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent 0%, var(--vermillion) 40%, var(--vermillion) 60%, transparent 100%);
  opacity: 0.5;
}

.nav-brand {
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: 0.1em;
  margin-right: 2.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.nav-brand-glyph { color: var(--vermillion); }

.nav-links { display: flex; align-items: center; gap: 0; }

.nav-link {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--text-soft);
  padding: 0.35rem 1rem;
  border: 1px solid transparent;
  transition: all 180ms;
  cursor: pointer;
  white-space: nowrap;
}

.nav-link:hover { color: var(--text); }

.nav-link.active {
  color: var(--vermillion);
  border-color: var(--vermillion);
  background: var(--vglow);
}

.nav-spacer { flex: 1; }

.nav-date {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--border);
  letter-spacing: 0.05em;
}

/* ═══════════════════════════════════════════════
   PAGE SHELL
═══════════════════════════════════════════════ */
.page {
  display: none;
  padding-top: var(--nav-h);
  min-height: 100vh;
}
.page.active { display: block; }

/* ═══════════════════════════════════════════════
   HOME PAGE — two-column academic layout
═══════════════════════════════════════════════ */
.home-wrap {
  max-width: 1060px;
  margin: 0 auto 0 max(1rem, 3vw);
  padding: 3.5rem 2rem 5rem 0;
  display: grid;
  grid-template-columns: var(--left-w) 1fr;
  gap: 2rem;
  align-items: start;
}

/* ─── Left col: sticky profile ─── */
.home-left {
  position: sticky;
  top: calc(var(--nav-h) + 2rem);
}

.profile-photo-wrap {
  position: relative;
  width: 180px;
  margin: 0 auto 1.6rem;
}

.profile-photo {
  width: 180px;
  height: 180px;
  object-fit: cover;
  border-radius: 2px;
  border: 1px solid var(--border);
  filter: grayscale(15%);
  display: block;
}

/* Corner bracket decoration */
.profile-photo-wrap::before,
.profile-photo-wrap::after {
  content: '';
  position: absolute;
  width: 14px; height: 14px;
  border-color: var(--vermillion);
  border-style: solid;
  opacity: 0.7;
}
.profile-photo-wrap::before {
  top: -5px; left: -5px;
  border-width: 1.5px 0 0 1.5px;
}
.profile-photo-wrap::after {
  bottom: -5px; right: -5px;
  border-width: 0 1.5px 1.5px 0;
}

.profile-name {
  font-family: var(--serif);
  font-size: 1.65rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.2;
  margin-bottom: 0.25rem;
  text-align: center;
}

.profile-name-en {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--vermillion);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-bottom: 0.9rem;
  text-align: center;
}

.profile-bio {
  font-size: 0.85rem;
  color: var(--text-soft);
  line-height: 1.7;
  margin-bottom: 1.2rem;
  text-align: center;
}

.profile-links {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  align-items: center;
}

.profile-link {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--text-soft);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: color 150ms;
}

.profile-link:hover { color: var(--gold); }

.profile-link-icon {
  width: 14px;
  text-align: center;
  color: var(--text-mute);
  font-size: 0.75rem;
}

/* ─── Right col: sections ─── */
.home-right { min-width: 0; padding-left: 3rem; }

.section {
  margin-bottom: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--border-soft);
}
.section:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }

.section-head {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  margin-bottom: 1.5rem;
}

.section-head::before {
  content: '';
  width: 3px;
  height: 1.1rem;
  background: var(--vermillion);
  flex-shrink: 0;
}

.section-title {
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-soft);
}

/* Research interests */
.interests {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.interest-chip {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--text-soft);
  border: 1px solid var(--border);
  padding: 0.22rem 0.65rem;
  transition: all 150ms;
}

.interest-chip:hover {
  color: var(--vermillion);
  border-color: var(--vermillion);
  background: var(--vglow);
}

/* ─── NEWS / Timeline ─── */
.news-timeline {
  position: relative;
  padding-left: 1.6rem;
}

.news-timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(to bottom, var(--vermillion), var(--border));
}

.news-item {
  position: relative;
  margin-bottom: 1.1rem;
  padding-left: 1.2rem;
}

.news-item:last-child { margin-bottom: 0; }

.news-dot {
  position: absolute;
  left: -1.6rem;
  top: 0.25rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--ink);
  border: 1.5px solid var(--vermillion);
  transform: translateX(-4.5px);
  z-index: 1;
}

.news-date {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--vermillion);
  letter-spacing: 0.08em;
  margin-bottom: 0.15rem;
}

.news-text {
  font-size: 0.85rem;
  color: var(--text-soft);
  line-height: 1.6;
}

.news-text strong {
  color: var(--text);
  font-weight: 500;
}

.news-text a {
  color: var(--gold);
  border-bottom: 1px solid var(--gold-soft);
  transition: border-color 150ms;
}

.news-text a:hover { border-color: var(--gold); }

/* ─── Publications ─── */
.pub-item {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 1.2rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-soft);
}

.pub-item:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }

.pub-thumb {
  width: 120px;
  height: 80px;
  object-fit: cover;
  border: 1px solid var(--border);
  border-radius: 2px;
  background: var(--ink-panel);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-mute);
  font-size: 1.5rem;
  flex-shrink: 0;
}

.pub-title {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 0.2rem;
  line-height: 1.4;
}

.pub-authors {
  font-size: 0.78rem;
  color: var(--text-soft);
  margin-bottom: 0.2rem;
}

.pub-venue {
  font-size: 0.75rem;
  color: var(--gold);
  font-style: italic;
  margin-bottom: 0.4rem;
}

.pub-links { display: flex; gap: 0.5rem; flex-wrap: wrap; }

.pub-link {
  font-family: var(--mono);
  font-size: 0.66rem;
  color: var(--text-soft);
  border: 1px solid var(--border);
  padding: 0.12rem 0.5rem;
  transition: all 150ms;
}

.pub-link:hover {
  color: var(--vermillion);
  border-color: var(--vermillion);
  background: var(--vglow);
}

/* ─── Education / Experience items ─── */
.edu-item {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 1rem;
  margin-bottom: 1.2rem;
  padding-bottom: 1.2rem;
  border-bottom: 1px solid var(--border-soft);
}
.edu-item:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }

.edu-period {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--text-mute);
  padding-top: 0.1rem;
  line-height: 1.5;
}

.edu-school {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 0.15rem;
}

.edu-degree {
  font-size: 0.78rem;
  color: var(--text-soft);
  line-height: 1.5;
}

/* ─── Projects highlight on home ─── */
.home-proj-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1rem;
  align-items: start;
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-soft);
}
.home-proj-item:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }

.home-proj-name {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 0.2rem;
}

.home-proj-desc {
  font-size: 0.78rem;
  color: var(--text-soft);
  margin-bottom: 0.3rem;
  line-height: 1.5;
}

.home-proj-stack {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--gold);
}

.home-proj-links { display: flex; gap: 0.4rem; flex-wrap: wrap; margin-top: 0.4rem; }

.small-link {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--text-soft);
  border: 1px solid var(--border);
  padding: 0.1rem 0.45rem;
  transition: all 150ms;
}

.small-link:hover {
  color: var(--vermillion);
  border-color: var(--vermillion);
  background: var(--vglow);
}

/* ═══════════════════════════════════════════════
   PROJECTS PAGE — Album Grid
═══════════════════════════════════════════════ */
.proj-page-wrap {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2.5rem 2rem 5rem;
}

.page-heading {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-mute);
  margin-bottom: 2rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.page-heading::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.proj-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
}

.proj-card {
  background: var(--ink-soft);
  position: relative;
  overflow: hidden;
  cursor: pointer;
  aspect-ratio: 16/10;
  display: block;
  transition: background 180ms;
}

.proj-card:hover { background: var(--ink-card); }

.proj-card-img {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  opacity: 0.35;
  transition: opacity 250ms;
}

.proj-card:hover .proj-card-img { opacity: 0.2; }

.proj-card-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--mono);
  font-size: 3rem;
  color: var(--border);
}

.proj-card-body {
  position: absolute;
  inset: 0;
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  background: linear-gradient(to top, rgba(12,12,14,0.97) 0%, rgba(12,12,14,0.3) 55%, transparent 100%);
}

.proj-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-bottom: 0.5rem;
  opacity: 0;
  transform: translateY(5px);
  transition: all 200ms;
}

.proj-card:hover .proj-card-tags { opacity: 1; transform: translateY(0); }

.proj-card-tag {
  font-family: var(--mono);
  font-size: 0.6rem;
  color: var(--vermillion);
  border: 1px solid var(--vermillion);
  padding: 0.08rem 0.35rem;
}

.proj-card-title {
  font-family: var(--serif);
  font-size: 1.05rem;
  color: var(--text);
  margin-bottom: 0.25rem;
  line-height: 1.3;
}

.proj-card-desc {
  font-size: 0.76rem;
  color: var(--text-soft);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ═══════════════════════════════════════════════
   STUDY PAGE — sidebar + posts
═══════════════════════════════════════════════ */
.study-layout {
  display: grid;
  grid-template-columns: 200px 1fr;
  min-height: calc(100vh - var(--nav-h));
}

.study-sidebar {
  border-right: 1px solid var(--border);
  background: var(--ink-soft);
  position: sticky;
  top: var(--nav-h);
  height: calc(100vh - var(--nav-h));
  overflow-y: auto;
  padding: 1.5rem 0;
}

.sb-section { margin-bottom: 1.5rem; }

.sb-label {
  font-family: var(--mono);
  font-size: 0.58rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-mute);
  padding: 0 1rem;
  margin-bottom: 0.4rem;
  display: block;
}

.sb-link {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  padding: 0.32rem 1rem;
  font-size: 0.78rem;
  color: var(--text-soft);
  cursor: pointer;
  border-left: 2px solid transparent;
  transition: all 150ms;
}

.sb-link:hover { color: var(--text); background: var(--ink-panel); }

.sb-link.active {
  color: var(--vermillion);
  background: var(--vglow);
  border-left-color: var(--vermillion);
}

.sb-cnt {
  font-family: var(--mono);
  font-size: 0.6rem;
  color: var(--text-mute);
  margin-left: auto;
}

.sb-arrow {
  font-size: 0.55rem;
  margin-right: 0.35rem;
  color: var(--text-mute);
  flex-shrink: 0;
}

.sb-sub {
  padding-left: 1.2rem;
  font-size: 0.74rem;
  color: var(--text-mute);
}

/* Search bar */
.search-wrap {
  padding: 0.7rem 1.2rem;
  border-bottom: 1px solid var(--border);
  background: var(--ink);
}

.search-input {
  width: 100%;
  background: var(--ink-panel);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--mono);
  font-size: 0.78rem;
  padding: 0.45rem 0.9rem;
  outline: none;
  transition: border-color 150ms;
}

.search-input:focus { border-color: var(--vermillion); }
.search-input::placeholder { color: var(--text-mute); }

/* Tag filter bar */
.tag-bar {
  padding: 0.8rem 1.2rem;
  border-bottom: 1px solid var(--border);
  background: var(--ink-soft);
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  align-items: center;
}

.tag-label {
  font-family: var(--mono);
  font-size: 0.6rem;
  color: var(--text-mute);
  letter-spacing: 0.1em;
  margin-right: 0.2rem;
}

.tag-btn {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--text-soft);
  border: 1px solid var(--border);
  background: none;
  padding: 0.15rem 0.55rem;
  cursor: pointer;
  transition: all 150ms;
}

.tag-btn:hover, .tag-btn.active {
  color: var(--vermillion);
  border-color: var(--vermillion);
  background: var(--vglow);
}

/* Posts list */
.study-main { display: flex; flex-direction: column; }

.posts-list { padding: 0.5rem 1.5rem 3rem; }

.post-row {
  border-bottom: 1px solid var(--border-soft);
  padding: 1rem 0;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1rem;
  align-items: start;
  cursor: pointer;
  transition: background 150ms;
}

.post-row:last-child { border-bottom: none; }

.post-row:hover {
  background: var(--ink-soft);
  margin: 0 -1.5rem;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.post-title {
  font-family: var(--serif);
  font-size: 0.95rem;
  color: var(--text);
  margin-bottom: 0.25rem;
  line-height: 1.4;
  transition: color 150ms;
}

.post-row:hover .post-title { color: var(--vermillion); }

.post-excerpt {
  font-size: 0.77rem;
  color: var(--text-soft);
  line-height: 1.6;
  margin-bottom: 0.4rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-tags { display: flex; flex-wrap: wrap; gap: 0.3rem; }

.post-tag {
  font-family: var(--mono);
  font-size: 0.62rem;
  color: var(--text-mute);
  border: 1px solid var(--border);
  padding: 0.08rem 0.38rem;
  transition: all 150ms;
  cursor: pointer;
}

.post-tag:hover {
  color: var(--vermillion);
  border-color: var(--vermillion);
}

.post-date {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--text-mute);
  white-space: nowrap;
  padding-top: 0.1rem;
}

/* ═══════════════════════════════════════════════
   POST / PROJECT DETAIL VIEW
═══════════════════════════════════════════════ */
.detail-wrap {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2.5rem 3rem 5rem;
  display: grid;
  grid-template-columns: 1fr 160px;
  gap: 1.5rem;
  align-items: start;
}

.detail-back {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--text-soft);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 1.8rem;
  transition: color 150ms;
}

.detail-back:hover { color: var(--vermillion); }

.detail-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.detail-cat {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--vermillion);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 0.7rem;
}

.detail-title {
  font-family: var(--serif);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.25;
  margin-bottom: 0.8rem;
}

.detail-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  align-items: center;
}

.detail-date {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--text-soft);
}

/* Markdown body */
.detail-body {
  font-size: 0.9rem;
  line-height: 1.88;
  color: var(--text-soft);
}

.detail-body h1, .detail-body h2, .detail-body h3, .detail-body h4 {
  font-family: var(--serif);
  color: var(--text);
  margin: 2.2rem 0 0.8rem;
  line-height: 1.3;
}

.detail-body h2 {
  font-size: 1.25rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
}

.detail-body h3 { font-size: 1.05rem; }
.detail-body h4 { font-size: 0.92rem; color: var(--text-soft); }

.detail-body p { margin-bottom: 1.2rem; }

.detail-body a {
  color: var(--gold);
  border-bottom: 1px solid rgba(196,146,60,0.3);
  transition: border-color 150ms;
}

.detail-body a:hover { border-color: var(--gold); }

.detail-body code {
  font-family: var(--mono);
  font-size: 0.81em;
  background: var(--ink-panel);
  border: 1px solid var(--border);
  padding: 0.1em 0.4em;
  color: var(--gold);
}

.code-wrap {
  margin: 1.5rem 0;
  border-radius: 4px;
  overflow: hidden;
  border: 1px solid var(--border);
}

.code-header {
  background: #2a2a2a;
  border-bottom: 1px solid var(--border);
  padding: 0 1rem;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.code-dots {
  display: flex;
  gap: 0.35rem;
}

.code-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--border);
}

.code-copy-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-mute);
  font-family: var(--mono);
  font-size: 0.62rem;
  padding: 0.15rem 0.55rem;
  cursor: pointer;
  transition: all 150ms;
  border-radius: 2px;
}

.code-copy-btn:hover { color: var(--text); border-color: var(--text-soft); }
.code-copy-btn.copied { color: #7ec8a4; border-color: #7ec8a4; }

.detail-body pre {
  background: #1e1e1e !important;
  border: none;
  border-radius: 0;
  padding: 1.2rem 1.4rem;
  overflow-x: auto;
  margin: 0;
}

.detail-body pre code {
  background: none !important;
  border: none;
  padding: 0;
  color: #d4d4d4;
  font-size: 0.82rem;
  font-family: var(--mono);
}

.detail-body blockquote {
  border-left: 3px solid var(--gold);
  padding: 0.7rem 1.2rem;
  margin: 1.5rem 0;
  background: var(--gold-soft);
  color: var(--text-soft);
  font-style: italic;
}

.detail-body ul, .detail-body ol {
  padding-left: 1.5rem;
  margin-bottom: 1.2rem;
}

.detail-body li { margin-bottom: 0.3rem; }

.detail-body hr {
  border: none;
  border-top: 1px solid var(--border-soft);
  margin: 2rem 0;
}

.detail-body img {
  max-width: 100%;
  border: 1px solid var(--border);
  margin: 1.5rem 0;
}

.detail-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.84rem;
}

.detail-body th {
  background: var(--ink-panel);
  border: 1px solid var(--border);
  padding: 0.55rem 0.9rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--text-soft);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: left;
}

.detail-body td {
  border: 1px solid var(--border);
  padding: 0.55rem 0.9rem;
  color: var(--text-soft);
}

/* Giscus comments */
.giscus-wrap {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

/* Prev / Next navigation */
.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.post-nav-btn {
  padding: 0.8rem 1rem;
  border: 1px solid var(--border);
  background: var(--ink-soft);
  cursor: pointer;
  transition: all 150ms;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
}

.post-nav-btn:hover {
  border-color: var(--vermillion);
  background: var(--vglow);
}

.post-nav-btn.next { flex-direction: row-reverse; }

.post-nav-label {
  font-family: var(--mono);
  font-size: 0.6rem;
  color: var(--text-mute);
  letter-spacing: 0.1em;
  flex-shrink: 0;
}

.post-nav-title {
  font-size: 0.82rem;
  color: var(--text-soft);
  line-height: 1.4;
  transition: color 150ms;
}

.post-nav-btn:hover .post-nav-title { color: var(--text); }

/* TOC */
.toc-panel {
  position: sticky;
  top: calc(var(--nav-h) + 2rem);
  max-height: calc(100vh - var(--nav-h) - 4rem);
  overflow-y: auto;
}

.toc-label {
  font-family: var(--mono);
  font-size: 0.6rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-mute);
  margin-bottom: 0.7rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.toc-list { list-style: none; }

.toc-list a {
  display: block;
  font-size: 0.76rem;
  color: var(--text-mute);
  padding: 0.22rem 0;
  padding-left: 0.8rem;
  border-left: 2px solid transparent;
  transition: all 150ms;
  line-height: 1.4;
}

.toc-list a:hover, .toc-list a.active {
  color: var(--text);
  border-left-color: var(--vermillion);
}

.toc-list .toc-h3 {
  padding-left: 1.5rem;
  font-size: 0.7rem;
}

/* ═══════════════════════════════════════════════
   FOOTER
═══════════════════════════════════════════════ */
.footer {
  border-top: 1px solid var(--border);
  padding: 1.2rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-text {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--text-mute);
}

.footer-text a { color: var(--text-mute); transition: color 150ms; }
.footer-text a:hover { color: var(--vermillion); }

/* ═══════════════════════════════════════════════
   SYNTAX HIGHLIGHTING
═══════════════════════════════════════════════ */
.highlight .c, .highlight .cm, .highlight .cp, .highlight .c1 { color: #4a5568; font-style: italic; }
.highlight .k, .highlight .kd, .highlight .kn { color: #b83228; }
.highlight .s, .highlight .s1, .highlight .s2 { color: #c4923c; }
.highlight .mi, .highlight .mf { color: #7ec8a4; }
.highlight .na, .highlight .nb, .highlight .nf { color: #7eb8f0; }
.highlight .nc { color: #7ec8a4; }
.highlight .nt { color: #b83228; }

/* ─── Scroll progress bar ─── */
.scroll-progress {
  position: fixed;
  top: var(--nav-h);
  left: 0;
  height: 2px;
  width: 0%;
  background: var(--vermillion);
  z-index: 199;
  transition: width 80ms linear;
  display: none;
}
.scroll-progress.visible { display: block; }

/* ═══════════════════════════════════════════════
   ANIMATIONS
═══════════════════════════════════════════════ */
.fade-in {
  animation: fadeIn 0.4s ease both;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Scrollbar */
::-webkit-scrollbar { width: 4px; height: 4px; }
::-webkit-scrollbar-track { background: var(--ink); }
::-webkit-scrollbar-thumb { background: var(--border); }
::-webkit-scrollbar-thumb:hover { background: var(--text-mute); }

/* ═══════════════════════════════════════════════
   RESPONSIVE
═══════════════════════════════════════════════ */
@media (max-width: 820px) {
  /* Nav */
  .nav { padding: 0 1rem; }
  .nav-date { display: none; }
  .nav-brand { margin-right: 1.2rem; }

  /* Home */
  .home-wrap {
    grid-template-columns: 1fr;
    padding: 2rem 1.4rem 4rem;
    margin: 0 auto;
    gap: 2rem;
  }
  .home-left {
    position: static;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    text-align: center;
  }
  .profile-photo-wrap { width: 130px; flex-shrink: 0; }
  .profile-photo { width: 130px; height: 130px; }
  .profile-name { font-size: 1.3rem; }
  .profile-links { align-items: center; }
  .home-right { padding-left: 0; }

  /* Study */
  .study-layout { grid-template-columns: 1fr; }
  .study-sidebar { display: none; }

  /* Detail */
  .detail-wrap {
    grid-template-columns: 1fr;
    padding: 1.8rem 1.4rem 4rem;
  }
  .toc-panel { display: none; }

  /* Publications */
  .pub-item { grid-template-columns: 1fr; }
  .pub-thumb { width: 100%; height: 120px; }

  /* Footer */
  .footer { flex-direction: column; gap: 0.4rem; text-align: center; padding: 1rem; }
}

@media (max-width: 480px) {
  /* Nav — very small screens */
  .nav-link { padding: 0.35rem 0.6rem; font-size: 0.68rem; }
  .nav-brand { font-size: 0.75rem; }

  /* Profile — smaller photo on very small screens */
  .profile-photo-wrap { width: 110px; }
  .profile-photo { width: 110px; height: 110px; }
  .profile-name { font-size: 1.15rem; }
  .profile-bio { font-size: 0.82rem; }

  /* Education — stack period above content */
  .edu-item {
    grid-template-columns: 1fr;
    gap: 0.2rem;
  }

  /* Home project period — below content */
  .home-proj-item {
    grid-template-columns: 1fr;
    gap: 0.3rem;
  }

  /* Detail title */
  .detail-title { font-size: 1.35rem; }

  /* Posts padding */
  .posts-list { padding: 0.5rem 1rem 3rem; }
  .post-row:hover { margin: 0 -1rem; padding-left: 1rem; padding-right: 1rem; }
}