/* =============================================================================
   Gu Lab @ JNU — Main Stylesheet
   - 깔끔한 학계 스타일 (al-folio 영감)
   - 라이트 모드 기본, 향후 다크 모드 손쉽게 확장 가능
   ========================================================================== */

:root {
  /* Warm, friendly academic palette — stone + indigo + amber */
  --color-bg: #fdfbf7;          /* warm off-white */
  --color-surface: #f9f5ef;     /* warm surface */
  --color-surface-alt: #f1ebe1; /* warm alt surface */
  --color-text: #2b2622;        /* warm near-black */
  --color-text-soft: #57514a;
  --color-text-mute: #8c8278;
  --color-border: #e9e1d5;      /* warm border */

  --color-accent: #5750dd;      /* warm indigo-violet */
  --color-accent-soft: #e8e6fb; /* light indigo wash */
  --color-accent-deep: #3f39ad;

  --color-accent2: #e08a16;     /* amber secondary */
  --color-accent2-soft: #fceccf;
  --color-accent2-deep: #b56a06;

  --font-sans: "Inter", "Noto Sans KR", system-ui, -apple-system, "Segoe UI",
    "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;

  --shadow-card: 0 1px 2px rgba(67, 47, 20, 0.04),
                 0 6px 18px rgba(67, 47, 20, 0.07);
  --shadow-lift: 0 4px 10px rgba(67, 47, 20, 0.06),
                 0 16px 40px rgba(67, 47, 20, 0.12);

  --container-max: 1080px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.15s ease;
}
a:hover { color: var(--color-accent-deep); text-decoration: underline; }

h1, h2, h3, h4 { font-weight: 700; line-height: 1.25; color: var(--color-text); margin-top: 0; }
h1 { font-size: 2.25rem; }
h2 { font-size: 1.6rem; margin-bottom: 0.75rem; }
h3 { font-size: 1.2rem; margin-bottom: 0.5rem; }

p { margin: 0 0 1rem; color: var(--color-text-soft); }

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ----------------------------- Header --------------------------------------*/
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--color-border);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  height: 68px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--color-text);
  font-weight: 700;
  text-decoration: none;
}
.brand:hover { text-decoration: none; }
.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent2) 130%);
  color: #fff;
  border-radius: 10px;
  font-weight: 800;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(87, 80, 221, 0.28);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name { font-size: 0.98rem; }
.brand-affil { font-size: 0.78rem; color: var(--color-text-mute); font-weight: 500; }

.site-nav {
  margin-left: auto;
  display: flex;
  gap: 1.5rem;
}
.site-nav a {
  color: var(--color-text-soft);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.4rem 0;
  border-bottom: 2px solid transparent;
}
.site-nav a:hover {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
  text-decoration: none;
}

.lang-toggle {
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 0.4rem 0.7rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s ease;
}
.lang-toggle:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  width: 36px;
  height: 36px;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  align-items: center;
  justify-content: center;
}
.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
}

/* ----------------------------- Hero / Home ---------------------------------*/
.hero {
  padding: 5rem 0 4rem;
  background:
    radial-gradient(ellipse at top right, var(--color-accent-soft) 0%, transparent 50%),
    radial-gradient(ellipse at bottom left, var(--color-accent2-soft) 0%, transparent 55%),
    linear-gradient(180deg, var(--color-bg) 0%, var(--color-surface) 100%);
  border-bottom: 1px solid var(--color-border);
}

/* ----------------------------- Venn diagram (research areas) -----------*/
.venn-container {
  margin: 2rem 0 1rem;
  display: flex;
  justify-content: center;
}
.venn-diagram {
  width: 100%;
  max-width: 700px;
  height: auto;
  display: block;
}
.venn-diagram .venn-orb {
  fill-opacity: 0.8;
  transition: fill-opacity 0.25s ease, transform 0.3s cubic-bezier(0.22, 1, 0.36, 1);
  transform-origin: center;
  transform-box: fill-box;
  cursor: pointer;
}
.venn-diagram .venn-orb:hover {
  fill-opacity: 0.97;
  transform: scale(1.06);
}
.venn-diagram .venn-gloss { pointer-events: none; }
.venn-label {
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 600;
  fill: var(--color-text);
}
.venn-center {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  fill: var(--color-text-mute);
  letter-spacing: 0.04em;
}

@media (max-width: 720px) {
  .venn-label { font-size: 14px; }
  .venn-center { font-size: 12px; }
}
@media (max-width: 480px) {
  .venn-label { font-size: 11px; }
  .venn-center { font-size: 10px; }
}

/* ----------------------------- Vanta NET Hero (animated network) -------- */
.hero.hero-vanta {
  position: relative;
  background:
    radial-gradient(ellipse at 75% 15%, rgba(87, 80, 221, 0.35) 0%, transparent 55%),
    radial-gradient(ellipse at 15% 90%, rgba(224, 138, 22, 0.18) 0%, transparent 50%),
    linear-gradient(160deg, #161430 0%, #11102a 100%);
  color: #fff;
  min-height: 540px;
  padding: 7rem 0 6rem;
  border-bottom: none;
  overflow: hidden;
}
.hero.hero-vanta .hero-inner {
  position: relative;
  z-index: 2;
}
.hero.hero-vanta h1 {
  color: #fff;
  text-shadow: 0 2px 24px rgba(0, 0, 0, 0.45);
}
.hero.hero-vanta .subtitle {
  color: rgba(255, 255, 255, 0.85);
  text-shadow: 0 1px 12px rgba(0, 0, 0, 0.4);
}
.hero.hero-vanta .tagline {
  background: rgba(96, 165, 250, 0.18);
  color: #93c5fd;
  border: 1px solid rgba(96, 165, 250, 0.35);
  backdrop-filter: blur(6px);
}
.hero.hero-vanta .btn-primary {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 4px 20px rgba(29, 78, 216, 0.45);
}
.hero.hero-vanta .btn-primary:hover {
  background: #2563eb;
  box-shadow: 0 6px 24px rgba(29, 78, 216, 0.6);
}
.hero.hero-vanta .btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.28);
  backdrop-filter: blur(8px);
}
.hero.hero-vanta .btn-secondary:hover {
  background: rgba(255, 255, 255, 0.18);
  border-color: rgba(255, 255, 255, 0.55);
  color: #fff;
}
.hero-inner { max-width: 760px; }
.hero h1 {
  font-size: 2.7rem;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}
.hero .tagline {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--color-accent);
  background: var(--color-accent-soft);
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  margin-bottom: 1rem;
}
.hero .subtitle {
  font-size: 1.1rem;
  color: var(--color-text-soft);
  margin-bottom: 2rem;
}
.hero-cta { display: flex; gap: 0.8rem; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.7rem 1.2rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: all 0.15s ease;
  border: 1px solid transparent;
  cursor: pointer;
}
.btn-primary { background: var(--color-accent); color: #fff; }
.btn-primary:hover { background: var(--color-accent-deep); color: #fff; text-decoration: none; }
.btn-secondary {
  background: #fff;
  color: var(--color-text);
  border-color: var(--color-border);
}
.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  text-decoration: none;
}

/* ----------------------------- Section --------------------------------------*/
.section { padding: 4rem 0; }
.section + .section { border-top: 1px solid var(--color-border); }
.section-title {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 0.78rem;
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}
.section-title::before {
  content: "";
  width: 22px;
  height: 2px;
  border-radius: 2px;
  background: var(--color-accent2);
}
.section-heading { font-size: 1.8rem; margin-bottom: 1.2rem; }

/* ----------------------------- Grid / cards --------------------------------*/
.grid {
  display: grid;
  gap: 1.2rem;
}
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.4rem;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}
.card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-lift);
  transform: translateY(-4px);
}
.card h3 { font-size: 1.05rem; margin-bottom: 0.5rem; }
.card p { font-size: 0.92rem; color: var(--color-text-soft); margin: 0; }

/* Tag pills */
.tags { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  background: var(--color-surface-alt);
  color: var(--color-text-soft);
  padding: 0.3rem 0.65rem;
  border-radius: 999px;
}
.tag.accent { background: var(--color-accent-soft); color: var(--color-accent-deep); }

/* ----------------------------- Research Interests (4 columns) ------------*/
.interests-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin-top: 1.5rem;
}
.interest-card {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
  padding: 1.4rem 1.2rem;
  border-radius: var(--radius-md);
  transition: background 0.2s ease, transform 0.2s ease;
}
.interest-card:hover {
  background: var(--color-surface);
  text-decoration: none;
  color: inherit;
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}
.interest-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  padding: 13px;
  border-radius: 16px;
  background: var(--color-accent-soft);
  color: var(--color-accent-deep);
  margin-bottom: 1rem;
  transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
}
.interest-card:hover .interest-icon {
  background: var(--color-accent);
  color: #fff;
  transform: scale(1.06) rotate(-3deg);
}
.interest-icon svg { width: 100%; height: 100%; }
.interest-card h3 {
  font-size: 1.05rem;
  margin: 0 0 0.5rem;
  font-weight: 700;
  color: var(--color-text);
}
.interest-card p {
  font-size: 0.9rem;
  color: var(--color-text-soft);
  line-height: 1.6;
  margin: 0;
}

@media (max-width: 900px) {
  .interests-grid { grid-template-columns: repeat(2, 1fr); gap: 1rem; }
}
@media (max-width: 480px) {
  .interests-grid { grid-template-columns: 1fr; }
}

/* ----------------------------- News split layout -------------------------*/
.news-split {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 3rem;
  align-items: start;
}
.news-side {
  position: sticky;
  top: 90px;
}
.news-side .section-title {
  margin-bottom: 0.4rem;
}
.news-side .section-heading {
  font-size: 1.8rem;
  margin-bottom: 0.8rem;
}
.view-all-link {
  display: inline-block;
  font-size: 0.9rem;
  color: var(--color-text-mute);
  text-decoration: none;
  transition: color 0.15s ease;
}
.view-all-link:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.news-list-detailed {
  list-style: none;
  padding: 0;
  margin: 0;
}
.news-list-detailed li {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 1.2rem;
  padding: 1rem 0;
  border-bottom: 1px dashed var(--color-border);
  font-size: 0.96rem;
}
.news-list-detailed li:first-child { padding-top: 0; }
.news-list-detailed li:last-child { border-bottom: none; }
.news-list-detailed .date {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text-mute);
  font-weight: 500;
  padding-top: 0.15rem;
}
.news-list-detailed .news-text {
  margin: 0;
  color: var(--color-text-soft);
  line-height: 1.6;
}
.news-list-detailed .news-text strong {
  color: var(--color-text);
  font-weight: 600;
}
.news-list-detailed .news-text em {
  font-style: italic;
  color: var(--color-text);
}

@media (max-width: 800px) {
  .news-split {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  .news-side { position: static; }
  .news-list-detailed li { grid-template-columns: 70px 1fr; gap: 0.8rem; }
}

/* ----------------------------- News page sections + Seminars -------------*/
.news-section-title {
  font-size: 1.25rem;
  margin-top: 3rem;
  margin-bottom: 1rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--color-border);
}
.news-section-title:first-of-type { margin-top: 1.5rem; }

.seminar-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.seminar-entry {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 1.2rem;
  padding: 1rem 0;
  border-bottom: 1px dashed var(--color-border);
}
.seminar-entry:last-child { border-bottom: none; }
.seminar-entry .date {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text-mute);
  font-weight: 500;
  padding-top: 0.15rem;
  line-height: 1.4;
}
.seminar-entry.upcoming .date {
  color: var(--color-accent);
  font-weight: 700;
}
.seminar-presenter {
  margin: 0;
  color: var(--color-text);
  line-height: 1.55;
}
.seminar-presenter strong {
  font-weight: 700;
  margin-right: 0.2rem;
  color: var(--color-text);
}
.seminar-title-text {
  color: var(--color-text-soft);
  font-style: italic;
}
.seminar-meta {
  margin: 0.3rem 0 0;
  font-size: 0.85rem;
  color: var(--color-text-mute);
}

/* News tag (used on Home page split list) */
.news-tag {
  display: inline-block;
  background: var(--color-accent-soft);
  color: var(--color-accent-deep);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.15rem 0.55rem;
  border-radius: 999px;
  margin-right: 0.45rem;
  vertical-align: middle;
  letter-spacing: 0.02em;
}

@media (max-width: 600px) {
  .seminar-entry { grid-template-columns: 110px 1fr; gap: 0.8rem; }
}

/* ----------------------------- News list ----------------------------------*/
.news-list { list-style: none; padding: 0; margin: 0; }
.news-list li {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 1rem;
  padding: 0.8rem 0;
  border-bottom: 1px dashed var(--color-border);
  font-size: 0.95rem;
}
.news-list li:last-child { border-bottom: none; }
.news-list .date {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text-mute);
}

/* ----------------------------- Members -------------------------------------*/
.members-group {
  margin-top: 4rem;
  margin-bottom: 1rem;
}
.members-group h3 {
  font-size: 1.05rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-mute);
  border-bottom: 2px solid var(--color-border);
  padding-bottom: 0.5rem;
  margin-bottom: 1.2rem;
}
.member-card {
  display: flex;
  flex-direction: column;
  text-align: center;
  align-items: center;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.4rem 1rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.member-card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-lift);
  transform: translateY(-4px);
}
.member-avatar {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  background: var(--color-surface-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--color-accent-deep);
  margin-bottom: 0.9rem;
  overflow: hidden;
  box-shadow: 0 0 0 3px var(--color-bg), 0 0 0 5px var(--color-accent-soft);
  transition: box-shadow 0.2s ease;
}
.member-card:hover .member-avatar {
  box-shadow: 0 0 0 3px var(--color-bg), 0 0 0 5px var(--color-accent);
}
.member-avatar img { width: 100%; height: 100%; object-fit: cover; }
.member-name { font-weight: 600; margin: 0; font-size: 1rem; }
.member-role {
  font-size: 0.85rem;
  color: var(--color-text-mute);
  margin: 0.1rem 0 0.5rem;
}
.member-card .member-interests {
  font-size: 0.8rem;
  color: var(--color-text-soft);
  margin: 0;
}

/* ----------------------------- Member card link --------------------------*/
a.member-card {
  text-decoration: none;
  color: inherit;
  cursor: pointer;
}
a.member-card:hover {
  text-decoration: none;
  color: inherit;
}

/* ----------------------------- Member detail page -------------------------*/
.back-link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text-mute);
  margin-bottom: 1.5rem;
  text-decoration: none;
}
.back-link:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.member-detail {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 2.5rem;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-card);
}
.member-detail-photo {
  width: 240px;
  height: 280px;
  border-radius: var(--radius-md);
  background: var(--color-surface-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-mute);
  font-size: 5rem;
  font-weight: 700;
  overflow: hidden;
}
.member-detail-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.member-detail-info h1 {
  font-size: 2rem;
  margin-bottom: 0.4rem;
}
.member-detail-role {
  font-size: 1rem;
  color: var(--color-accent);
  font-weight: 500;
  margin-bottom: 0.8rem;
}
.member-detail-interests {
  font-size: 0.95rem;
  color: var(--color-text-soft);
  font-style: italic;
  margin-bottom: 1.2rem;
}
.member-detail-meta {
  margin-bottom: 1.2rem;
  font-size: 0.95rem;
}
.member-detail-meta p {
  margin: 0.2rem 0;
}
.member-detail-meta .label {
  color: var(--color-text-mute);
  font-weight: 500;
  margin-right: 0.4rem;
}
.member-detail-links {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  margin-top: 0.6rem;
}

.member-detail-content {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem 2.5rem;
}
.member-detail-content h2 {
  font-size: 1.3rem;
  margin-top: 2rem;
  margin-bottom: 0.8rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--color-border);
}
.member-detail-content h2:first-child { margin-top: 0; }
.member-detail-content h3 {
  font-size: 1.05rem;
  margin-top: 1.4rem;
  margin-bottom: 0.5rem;
}
.member-detail-content ul {
  padding-left: 1.4rem;
  color: var(--color-text-soft);
}
.member-detail-content li { margin-bottom: 0.4rem; }
.member-detail-content em {
  color: var(--color-text-mute);
  font-style: italic;
}

@media (max-width: 720px) {
  .member-detail {
    grid-template-columns: 1fr;
    padding: 1.5rem;
    gap: 1.5rem;
  }
  .member-detail-photo {
    width: 100%;
    height: 320px;
  }
  .member-detail-content {
    padding: 1.5rem;
  }
}

/* ----------------------------- Professor card ------------------------------*/
.prof-card {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 2rem;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-card);
}
.prof-photo {
  width: 200px;
  height: 240px;
  border-radius: var(--radius-md);
  background: var(--color-surface-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-mute);
  font-size: 4rem;
  font-weight: 700;
  overflow: hidden;
}
.prof-photo img { width: 100%; height: 100%; object-fit: cover; }
.prof-name { font-size: 1.6rem; margin-bottom: 0.2rem; }
.prof-title { font-size: 0.95rem; color: var(--color-text-mute); margin-bottom: 1rem; }
.prof-meta { display: flex; gap: 1.5rem; flex-wrap: wrap; font-size: 0.9rem; color: var(--color-text-soft); margin-bottom: 1rem; }
.prof-meta .label { color: var(--color-text-mute); margin-right: 0.3rem; font-weight: 500; }

/* ----------------------------- Professor citation stats ------------------*/
.prof-stats {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 0.9rem 1.3rem;
  margin: 0.4rem 0 1rem;
  width: fit-content;
  flex-wrap: wrap;
}
.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 64px;
}
.stat-num {
  font-family: var(--font-mono);
  font-size: 1.55rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}
.stat-label {
  font-size: 0.78rem;
  color: var(--color-text-mute);
  margin-top: 0.35rem;
  letter-spacing: 0.02em;
  font-weight: 500;
}
.stat-source {
  font-size: 0.72rem;
  color: var(--color-text-mute);
  font-style: italic;
  border-left: 1px solid var(--color-border);
  padding-left: 1rem;
  margin-left: 0.2rem;
}

@media (max-width: 600px) {
  .prof-stats { gap: 1rem; padding: 0.7rem 1rem; }
  .stat-num { font-size: 1.3rem; }
  .stat-source { display: none; }
}

/* ----------------------------- Professor sub-sections (Education / Exp) -- */
.prof-section {
  margin: 2rem 0 0;
  padding-left: 1rem;
  border-left: 4px solid var(--color-accent);
}
.prof-section-title {
  font-size: 1.2rem;
  margin-bottom: 0.7rem;
  color: var(--color-text);
}
.prof-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.prof-list li {
  margin-bottom: 0.55rem;
  font-size: 0.95rem;
  color: var(--color-text-soft);
  line-height: 1.55;
}
.prof-list li strong {
  color: var(--color-text);
  font-weight: 600;
  margin-right: 0.25rem;
}

/* ----------------------------- Publications --------------------------------*/
.pub-year {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-top: 2rem;
  margin-bottom: 0.6rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--color-border);
}
.pub-list { list-style: none; padding: 0; margin: 0; }
.pub-item {
  padding: 1rem 0;
  border-bottom: 1px dashed var(--color-border);
}
.pub-item:last-child { border-bottom: none; }
.pub-title { font-weight: 600; color: var(--color-text); margin: 0 0 0.2rem; font-size: 1rem; }
.pub-authors { font-size: 0.92rem; color: var(--color-text-soft); margin: 0 0 0.2rem; }
.pub-authors strong { color: var(--color-accent-deep); }
.pub-venue {
  font-style: italic;
  font-size: 0.9rem;
  color: var(--color-text-mute);
  margin: 0 0 0.4rem;
}
.pub-links { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.pub-link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 0.25rem 0.6rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-soft);
}
.pub-link:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  text-decoration: none;
}
.bibtex {
  margin-top: 0.6rem;
  background: #0f172a;
  color: #e2e8f0;
  padding: 0.9rem 1rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  white-space: pre;
  overflow-x: auto;
  display: none;
}
.bibtex.is-open { display: block; }

/* ----------------------------- Research page (groups & projects) ----------*/
.research-group {
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
}
.research-group:first-of-type {
  margin-top: 2rem;
  padding-top: 0;
  border-top: none;
}
.research-group-title {
  font-size: 1.7rem;
  margin-bottom: 0.8rem;
  position: relative;
  padding-left: 1rem;
}
.research-group-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.3rem;
  bottom: 0.3rem;
  width: 4px;
  background: var(--color-accent);
  border-radius: 2px;
}
.research-group-intro {
  font-size: 1rem;
  color: var(--color-text-soft);
  margin-bottom: 2rem;
  max-width: 800px;
  line-height: 1.7;
}

.project-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.project-card {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 1.8rem;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  transition: border-color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}
.project-card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-lift);
  transform: translateY(-4px);
}
.project-figure img { transition: transform 0.35s ease; }
.project-card:hover .project-figure img { transform: scale(1.05); }

.project-figure {
  width: 320px;
  height: 200px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}
.project-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.project-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: rgba(255, 255, 255, 0.95);
  text-align: center;
  padding: 1rem;
}
.ph-acronym {
  font-family: var(--font-mono);
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.25);
}
.ph-venue {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  margin-top: 0.6rem;
  opacity: 0.85;
  background: rgba(0, 0, 0, 0.18);
  padding: 0.25rem 0.7rem;
  border-radius: 12px;
  backdrop-filter: blur(2px);
}

.project-info {
  display: flex;
  flex-direction: column;
}
.project-title {
  font-size: 1.15rem;
  margin: 0 0 0.5rem;
  color: var(--color-text);
}
.project-desc {
  font-size: 0.95rem;
  color: var(--color-text-soft);
  line-height: 1.65;
  margin: 0 0 0.9rem;
}
.project-paper {
  font-size: 0.85rem;
  color: var(--color-text-mute);
  margin: auto 0 0;
  padding-top: 0.5rem;
  border-top: 1px dashed var(--color-border);
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  align-items: baseline;
}
.paper-icon { font-size: 0.95rem; }
.paper-title {
  color: var(--color-text);
  font-weight: 500;
  font-style: italic;
}
.paper-venue {
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 0.78rem;
}

@media (max-width: 800px) {
  .project-card {
    grid-template-columns: 1fr;
    gap: 1.2rem;
  }
  .project-figure {
    width: 100%;
    height: 220px;
  }
  .research-group-title { font-size: 1.4rem; }
}

/* ----------------------------- Research cards ------------------------------*/
.research-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.6rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  transition: all 0.18s ease;
}
.research-card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-lift);
  transform: translateY(-4px);
}
.research-card .icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: var(--color-accent-soft);
  color: var(--color-accent-deep);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 700;
  font-family: var(--font-mono);
}

/* ----------------------------- Contact page ------------------------------*/
.contact-grid {
  display: flex;
  flex-direction: column;
  gap: 2rem;
  margin-top: 2rem;
}
.contact-block {
  border-top: 1px solid var(--color-border);
  padding-top: 1.5rem;
}
.contact-block:first-child { border-top: none; padding-top: 0; }
.contact-heading {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-mute);
  margin-bottom: 0.7rem;
}
.contact-line {
  font-size: 1rem;
  color: var(--color-text-soft);
  line-height: 1.7;
  margin: 0 0 0.6rem;
}
.contact-line strong { color: var(--color-text); font-weight: 600; }
.contact-map {
  margin-top: 1rem;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-card);
}

/* ----------------------------- Footer --------------------------------------*/
.site-footer {
  margin-top: 4rem;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  color: var(--color-text-soft);
  font-size: 0.92rem;
}
.footer-inner {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  padding: 2.5rem 1.5rem 1.5rem;
  max-width: var(--container-max);
  margin: 0 auto;
}
.footer-col h4 { font-size: 0.95rem; color: var(--color-text); margin-bottom: 0.6rem; }
.footer-col p { margin: 0.2rem 0; font-size: 0.9rem; }
.footer-bottom {
  text-align: center;
  border-top: 1px solid var(--color-border);
  padding: 1rem;
  color: var(--color-text-mute);
  font-size: 0.82rem;
}

/* ----------------------------- Responsive ----------------------------------*/
@media (max-width: 820px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .prof-card { grid-template-columns: 1fr; }
  .prof-photo { width: 100%; height: 280px; }
  .footer-inner { grid-template-columns: 1fr; gap: 1.4rem; }

  .menu-toggle { display: flex; }
  .site-nav {
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 1rem 1.5rem;
    gap: 0.8rem;
    display: none;
  }
  .site-nav.is-open { display: flex; }
}

@media (max-width: 520px) {
  .hero { padding: 3rem 0; }
  .hero h1 { font-size: 2rem; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .news-list li { grid-template-columns: 1fr; gap: 0.2rem; }
}

/* ----------------------------- Scroll reveal animations ------------------- */
@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0;
    transform: translateY(26px);
    transition: opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1),
                transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
    will-change: opacity, transform;
  }
  .reveal.is-visible {
    opacity: 1;
    transform: none;
  }
  /* Staggered children (cards inside a grid/list) */
  .reveal-group > * {
    opacity: 0;
    transform: translateY(22px);
    transition: opacity 0.55s cubic-bezier(0.22, 1, 0.36, 1),
                transform 0.55s cubic-bezier(0.22, 1, 0.36, 1);
    transition-delay: var(--reveal-delay, 0ms);
  }
  .reveal-group.is-visible > * {
    opacity: 1;
    transform: none;
  }
}