/* ==========================================================================
   SC Lab — Base tokens
   ========================================================================== */
:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f5f7fb;
  --color-text: #1c2230;
  --color-text-muted: #5b6474;
  --color-border: #e4e8f0;
  --color-primary: #1f3a8f;
  --color-primary-dark: #16296b;
  --color-primary-light: #eef1fb;
  --color-accent: #2f6fed;

  --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", "Pretendard",
    "Noto Sans KR", Roboto, Helvetica, Arial, sans-serif;

  --max-width: 1120px;
  --radius: 10px;
  --shadow: 0 4px 16px rgba(20, 30, 60, 0.06);
  --shadow-hover: 0 10px 28px rgba(20, 30, 60, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-base);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

img {
  max-width: 100%;
  display: block;
}

/* ==========================================================================
   Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.logo span {
  color: var(--color-primary);
}

.logo:hover {
  text-decoration: none;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.main-nav a {
  color: var(--color-text);
  font-weight: 500;
  font-size: 0.95rem;
}

.main-nav a:hover {
  color: var(--color-primary);
  text-decoration: none;
}

.main-nav a.active {
  color: var(--color-primary);
  font-weight: 700;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  margin: 0 auto;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  background: linear-gradient(160deg, var(--color-primary-light) 0%, #ffffff 65%);
  padding: 96px 0 80px;
  border-bottom: 1px solid var(--color-border);
}

.eyebrow {
  color: var(--color-primary);
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin: 0 0 12px;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  line-height: 1.2;
  margin: 0 0 20px;
  letter-spacing: -0.02em;
}

.hero h1 .accent {
  color: var(--color-primary);
}

.hero-desc {
  max-width: 620px;
  color: var(--color-text-muted);
  font-size: 1.05rem;
  margin: 0 0 32px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: var(--shadow);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  box-shadow: var(--shadow-hover);
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 1.5px solid var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-primary-light);
}

/* ==========================================================================
   Page header (banner for inner pages)
   ========================================================================== */
.page-header {
  background: linear-gradient(160deg, var(--color-primary-light) 0%, #ffffff 65%);
  padding: 56px 0;
  border-bottom: 1px solid var(--color-border);
}

.page-header h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  margin: 0;
  letter-spacing: -0.02em;
}

.page-header .eyebrow {
  margin-bottom: 8px;
}

.page-lede {
  margin: 14px 0 0;
  color: var(--color-text-muted);
  font-size: 1rem;
}

/* Home quick-links */
.card-link {
  display: block;
  color: inherit;
}

.card-link:hover {
  text-decoration: none;
}

.card-link .card-arrow {
  display: inline-block;
  margin-top: 12px;
  color: var(--color-primary);
  font-weight: 600;
  font-size: 0.88rem;
}

/* ==========================================================================
   Sections
   ========================================================================== */
.section {
  padding: 88px 0;
}

.section-alt {
  background: var(--color-bg-alt);
}

.section-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: 0 0 12px;
  letter-spacing: -0.01em;
}

.section-desc {
  color: var(--color-text-muted);
  margin: 0 0 40px;
  max-width: 640px;
}

/* About */
.about-text p {
  color: var(--color-text-muted);
  margin: 0 0 16px;
}

.about-facts {
  margin-top: 24px;
  display: grid;
  gap: 10px;
}

.about-facts li {
  font-size: 0.95rem;
}

.about-facts strong {
  display: inline-block;
  width: 90px;
  color: var(--color-text);
}

.contact-map iframe {
  width: 100%;
  aspect-ratio: 4 / 3;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.research-figure {
  width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow);
  margin-bottom: 32px;
}

/* Research cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 20px;
}

.card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: box-shadow 0.15s ease, transform 0.15s ease;
}

.card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
}

.card-icon {
  font-size: 1.8rem;
  margin-bottom: 12px;
}

.card h3 {
  margin: 0 0 8px;
  font-size: 1.1rem;
}

.card p {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.92rem;
}

/* Members */
.member-group-title {
  font-size: 1.05rem;
  color: var(--color-text);
  margin: 40px 0 20px;
  padding-top: 8px;
  border-top: 1px solid var(--color-border);
}

.member-group-title:first-of-type {
  margin-top: 0;
  border-top: none;
  padding-top: 0;
}

.prof-card {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 32px;
  align-items: start;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
}

.prof-card img {
  width: 100%;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: 8px;
  display: block;
}

.prof-card h4 {
  margin: 0 0 4px;
  font-size: 1.3rem;
}

.prof-card .role {
  color: var(--color-primary);
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.02em;
  margin: 0 0 14px;
}

.prof-card p {
  margin: 0 0 12px;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

.prof-subhead {
  margin: 0 0 8px;
  color: var(--color-primary);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.career-list {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
}

.career-list li {
  display: flex;
  gap: 16px;
  padding: 8px 0;
  border-bottom: 1px dashed var(--color-border);
  font-size: 0.9rem;
}

.career-list li:first-child {
  padding-top: 0;
}

.career-period {
  flex: none;
  width: 150px;
  color: var(--color-text-muted);
  font-weight: 600;
}

.career-desc {
  color: var(--color-text);
}

.career-list + .prof-subhead {
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
}

.prof-card .contact {
  font-size: 0.9rem;
  color: var(--color-text);
  margin: 0;
}

.prof-card .contact a {
  color: var(--color-primary);
}

.member-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 20px;
}

.member-grid-alumni {
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
}

.member-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.member-card.small {
  text-align: left;
  padding: 16px 18px;
}

.member-photo {
  width: 100%;
  aspect-ratio: 3 / 4;
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-weight: 700;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.member-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.member-card-body {
  padding: 14px 16px 18px;
  text-align: center;
}

.member-card h4 {
  margin: 0 0 4px;
  font-size: 1rem;
}

.member-role {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.88rem;
}

.member-links a {
  font-size: 0.85rem;
}

@media (max-width: 640px) {
  .prof-card {
    grid-template-columns: 1fr;
  }

  .prof-card img {
    max-width: 200px;
    aspect-ratio: 3 / 4;
  }

  .career-list li {
    flex-direction: column;
    gap: 2px;
  }

  .career-period {
    width: auto;
  }
}

/* Publications */
.pub-filter {
  display: flex;
  gap: 8px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 8px 18px;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: #fff;
  color: var(--color-text-muted);
  font-weight: 600;
  font-size: 0.88rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.filter-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.filter-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

.pub-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.pub-item {
  display: flex;
  gap: 20px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px 24px;
}

.pub-item.is-hidden {
  display: none;
}

.pub-year {
  flex: none;
  width: 56px;
  font-weight: 700;
  color: var(--color-primary);
  font-size: 1.05rem;
}

.pub-body h4 {
  margin: 0 0 6px;
  font-size: 1rem;
  line-height: 1.4;
}

.pub-authors {
  margin: 0 0 4px;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.pub-venue {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.88rem;
  font-style: italic;
}

.pub-tag {
  display: inline-block;
  font-style: normal;
  font-weight: 600;
  font-size: 0.75rem;
  color: var(--color-primary);
  background: var(--color-primary-light);
  border-radius: 999px;
  padding: 2px 10px;
  margin-left: 4px;
}

/* News */
.news-list {
  display: flex;
  flex-direction: column;
}

.news-item {
  display: flex;
  gap: 24px;
  padding: 18px 0;
  border-bottom: 1px solid var(--color-border);
}

.news-item:first-child {
  border-top: 1px solid var(--color-border);
}

.news-item time {
  flex: none;
  width: 110px;
  color: var(--color-text-muted);
  font-size: 0.88rem;
  font-weight: 600;
}

.news-item p {
  margin: 0;
}

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 48px;
  align-items: start;
}

.contact-info p {
  margin: 0 0 20px;
  color: var(--color-text-muted);
}

.contact-info strong {
  display: block;
  color: var(--color-text);
  margin-bottom: 4px;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  padding: 32px 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.88rem;
}

.visitor-count {
  display: inline-flex;
  align-items: stretch;
  border-radius: 3px;
  overflow: hidden;
  font-size: 0.72rem;
  font-weight: 600;
  line-height: 1;
}

.visitor-count-label {
  background: #555555;
  color: #fff;
  padding: 5px 7px;
}

.visitor-count-value {
  background: var(--color-primary);
  color: #fff;
  padding: 5px 7px;
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 860px) {
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .contact-map {
    order: -1;
  }
}

@media (max-width: 720px) {
  .main-nav {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: 12px 24px 24px;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-140%);
    opacity: 0;
    transition: transform 0.2s ease, opacity 0.2s ease;
  }

  .main-nav.is-open {
    transform: translateY(0);
    opacity: 1;
  }

  .main-nav a {
    padding: 10px 0;
    border-bottom: 1px solid var(--color-border);
  }

  .nav-toggle {
    display: flex;
  }

  .nav-toggle.is-open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle.is-open span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle.is-open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .hero {
    padding: 64px 0 56px;
  }

  .section {
    padding: 64px 0;
  }

  .pub-item {
    flex-direction: column;
    gap: 8px;
  }

  .news-item {
    flex-direction: column;
    gap: 4px;
  }

  .news-item time {
    width: auto;
  }
}