/* =====================================================
   APCL Lab Site — Visual System
   Concept: a night-time static-fire test cell.
   Dark graphite ground, flame-gradient ignition accent,
   cool telemetry blue for data/links, thrust-curve motif
   as the recurring section divider.
   ===================================================== */

:root{
  --bg:        #12151a;
  --bg-panel:  #1b1f27;
  --bg-panel-2:#20252e;
  --line:      #2a3038;
  --text:      #e9ebee;
  --text-dim:  #9aa3b0;
  --text-faint:#6b7280;

  --flame-1:   #2f8fef;
  --flame-2:   #7dd3fc;
  --flame-grad: linear-gradient(90deg, var(--flame-1), var(--flame-2));
  --telemetry: #6cb6ff;
  --on-accent: #071726;

  --radius: 3px;

  --font-display: "Space Grotesk", "Pretendard", "Noto Sans KR", sans-serif;
  --font-body: "Inter", "Pretendard", "Noto Sans KR", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

*{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }

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

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

a{ color: var(--telemetry); text-decoration: none; }
a:hover{ text-decoration: underline; }

h1,h2,h3,h4{
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0 0 0.5em;
  color: var(--text);
}

.mono{ font-family: var(--font-mono); }

.wrap{
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Skip link / focus ---------- */
.skip-link{
  position: absolute; left: -999px; top: auto;
  background: var(--flame-2); color: #12151a; padding: 8px 14px;
  z-index: 999; border-radius: var(--radius);
}
.skip-link:focus{ left: 24px; top: 24px; }

:focus-visible{
  outline: 2px solid var(--flame-2);
  outline-offset: 2px;
}

/* ---------- Top nav ---------- */
.site-header{
  position: sticky; top: 0; z-index: 100;
  background: rgba(18,21,26,0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.nav{
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 24px;
  max-width: 1280px; margin: 0 auto;
}
.nav-brand{
  display: flex; align-items: center; gap: 12px;
  font-family: var(--font-display); font-weight: 700; font-size: 1.15rem;
  color: var(--text); text-decoration: none;
}
.nav-brand:hover{ text-decoration: none; }
.nav-brand .lab-code{
  font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.08em;
  color: var(--flame-2); border: 1px solid var(--flame-2);
  padding: 2px 6px; border-radius: var(--radius);
}
.nav-brand .lab-logo{
  height: 46px; width: auto; object-fit: contain;
}
.nav-links{
  list-style: none; display: flex; gap: 4px; margin: 0; padding: 0;
}
.nav-links a{
  display: inline-block; padding: 8px 12px; border-radius: var(--radius);
  color: var(--text-dim); font-size: 0.92rem; font-weight: 500;
}
.nav-links a:hover, .nav-links a.active{
  color: var(--text); text-decoration: none; background: var(--bg-panel);
}
.nav-toggle{ display:none; }

@media (max-width: 760px){
  .nav-links{
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; background: var(--bg-panel);
    border-bottom: 1px solid var(--line);
    max-height: 0; overflow: hidden; transition: max-height .25s ease;
  }
  .nav-links.open{ max-height: 400px; }
  .nav-links a{ padding: 14px 24px; border-radius: 0; }
  .nav-toggle{
    display: inline-flex; background: none; border: 1px solid var(--line);
    color: var(--text); padding: 6px 10px; border-radius: var(--radius);
    font-size: 1.1rem; cursor: pointer;
  }
}

/* ---------- Recruiting banner ---------- */
.recruit-banner{
  background: var(--flame-grad);
  color: var(--on-accent);
  font-weight: 600;
  text-align: center;
  padding: 10px 16px;
  font-size: 0.9rem;
}
.recruit-banner a{ color: var(--on-accent); text-decoration: underline; }

/* ---------- Hero (Home) ---------- */
.hero{
  position: relative;
  min-height: 92vh;
  display: flex; align-items: center;
  overflow: hidden;
  background: radial-gradient(ellipse at 50% 20%, #1a2130 0%, #12151a 70%);
  border-bottom: 1px solid var(--line);
}
.hero-media{
  position: absolute; inset: 0; z-index: 0;
}
.hero-media video, .hero-media iframe, .hero-media img.hero-gif{
  width: 100%; height: 100%; object-fit: cover;
  opacity: 1;
}
.hero-media img.hero-gif{
  filter: brightness(1.18) contrast(1.08) saturate(1.15);
}
.hero-media::after{
  content: "";
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(18,21,26,0.0) 0%, rgba(18,21,26,0.05) 45%, rgba(18,21,26,0.55) 100%);
}
.hero-fallback{
  position:absolute; inset:0; z-index:0;
  background:
    radial-gradient(circle at 30% 30%, rgba(47,143,239,0.20), transparent 45%),
    radial-gradient(circle at 70% 60%, rgba(125,211,252,0.14), transparent 50%);
}
.hero-content{
  position: relative; z-index: 1;
  padding: 24px 24px;
  max-width: 1280px; margin: 0 auto; width: 100%;
}
.hero-eyebrow{
  font-family: var(--font-mono); font-size: 0.8rem; letter-spacing: 0.12em;
  color: var(--flame-2); text-transform: uppercase; margin-bottom: 14px;
  text-shadow: 0 1px 4px rgba(0,0,0,0.85), 0 2px 16px rgba(0,0,0,0.7);
}
.hero h1{
  font-size: clamp(2.1rem, 5vw, 3.4rem);
  line-height: 1.1; margin-bottom: 14px;
  text-shadow: 0 1px 6px rgba(0,0,0,0.85), 0 4px 26px rgba(0,0,0,0.75);
}
.hero h1 .en{
  display:block; font-size: 0.42em; color: var(--text-dim); font-weight: 500;
  margin-top: 8px; letter-spacing: 0.02em;
}
.hero p.lead{
  color: var(--text-dim); font-size: 1.05rem; max-width: 560px; margin-bottom: 26px;
  text-shadow: 0 1px 4px rgba(0,0,0,0.85), 0 2px 16px rgba(0,0,0,0.7);
}
.hero-ctas{ display: flex; gap: 12px; flex-wrap: wrap; }
.btn{
  display: inline-block; padding: 11px 20px; border-radius: var(--radius);
  font-weight: 600; font-size: 0.92rem; border: 1px solid var(--line);
}
.btn:hover{ text-decoration: none; }
.btn-primary{
  background: var(--flame-grad); color: var(--on-accent); border: none;
}
.btn-ghost{
  background: transparent; color: var(--text); border-color: var(--line);
}
.btn-ghost:hover{ border-color: var(--text-dim); }

/* ---------- Thrust-curve divider (signature motif) ---------- */
.thrust-divider{
  width: 100%; height: 46px; display: block;
  margin: 0 auto;
}
.thrust-divider path{
  fill: none; stroke: url(#thrustGrad); stroke-width: 2;
}

/* ---------- Partners / affiliation banner ---------- */
.partners-banner{
  padding: 36px 0 28px;
  border-bottom: 1px solid var(--line);
  text-align: center;
}
.partners-line{
  color: var(--flame-2); font-family: var(--font-mono); font-size: 0.82rem;
  letter-spacing: 0.02em; margin-bottom: 22px;
}
.partners-logos{
  display: flex; align-items: center; justify-content: center;
  gap: 40px; flex-wrap: wrap; margin-bottom: 14px;
}
.partner-logo{ display: inline-flex; align-items: center; }
.partner-logo img{
  height: 44px; width: auto; max-width: 180px; object-fit: contain;
  filter: grayscale(1) brightness(1.6);
  opacity: 0.75; transition: opacity .2s ease, filter .2s ease;
}
.partner-logo:hover img{ opacity: 1; filter: none; }
.partners-updated{ color: var(--text-faint); font-family: var(--font-mono); font-size: 0.75rem; }

/* ---------- Sections ---------- */
.section{ padding: 72px 0; border-bottom: 1px solid var(--line); }
.section:last-of-type{ border-bottom: none; }
.section-head{ margin-bottom: 36px; }
.section-eyebrow{
  font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.1em;
  color: var(--flame-2); text-transform: uppercase; display:block; margin-bottom: 10px;
}
.section h2{ font-size: 1.85rem; }
.section-sub{ color: var(--text-dim); max-width: 920px; margin-top: 8px; }
.research-intro .section-sub{ max-width: none; }

/* ---------- Research cards ---------- */
.research-grid{
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px,1fr));
  gap: 20px;
}
.research-grid-home{
  grid-template-columns: repeat(2, minmax(0,1fr));
}
.research-card{
  background: var(--bg-panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; overflow: hidden;
}
.research-card-link{
  display: block;
  color: inherit;
  min-height: 0;
  transition: transform .16s ease, border-color .16s ease, background .16s ease;
}
.research-grid-home .research-card{
  padding: 20px 24px;
}
.research-card-link:hover{
  text-decoration: none;
  transform: translateY(-2px);
  border-color: var(--flame-1);
  background: var(--bg-panel-2);
}
.research-img{
  width: calc(100% + 48px); margin: -24px -24px 18px;
  aspect-ratio: 16/10; object-fit: cover; border-bottom: 1px solid var(--line);
}
.research-card .idx, .research-feature .idx{
  font-family: var(--font-mono); color: var(--flame-2); font-size: 0.85rem;
  display:inline-block; margin: 0 10px 0 0;
}
.research-card h3{
  display: inline;
  font-size: 1.05rem;
  margin: 0;
}
.research-card p{ color: var(--text-dim); font-size: 0.92rem; margin: 10px 0 0; }

.research-feature-list{
  display: grid;
  gap: 36px;
}
.research-feature{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 32px;
  align-items: center;
  padding: 32px 0;
  border-bottom: 1px solid var(--line);
  scroll-margin-top: 110px;
}
.research-feature:nth-child(odd) .research-feature-media{ order: 2; }
.research-feature:nth-child(odd) .research-feature-body{ order: 1; }
.research-feature:nth-child(even) .research-feature-media{ order: 1; }
.research-feature:nth-child(even) .research-feature-body{ order: 2; }
.research-feature:first-child{ padding-top: 0; }
.research-feature:last-child{ border-bottom: none; padding-bottom: 0; }
.research-feature-media{
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}
.research-feature-media img{
  display: block;
  width: 100%;
  height: auto;
  object-fit: contain;
  background: #fff;
}
.research-feature-body h3{
  display: inline;
  font-size: 1.35rem;
  margin: 0;
}
.research-feature-body p{
  color: var(--text-dim);
  margin: 14px 0 12px;
}
.research-feature-body p + p{ margin-top: 0; }
.research-feature-body p:last-child{ margin-bottom: 0; }

@media (max-width: 760px){
  .research-grid-home{ grid-template-columns: 1fr; }
  .research-feature{
    grid-template-columns: 1fr;
    gap: 18px;
  }
  .research-feature:nth-child(n) .research-feature-media,
  .research-feature:nth-child(n) .research-feature-body{ order: 0; }
}

/* ---------- Board (News & Gallery / shared with Publications) ---------- */
.board-toolbar{ margin-bottom: 20px; }
.board-search{
  width: 100%; max-width: 360px; padding: 10px 14px;
  background: var(--bg-panel); border: 1px solid var(--line); border-radius: var(--radius);
  color: var(--text); font-family: var(--font-body); font-size: 0.92rem;
}
.board-search::placeholder{ color: var(--text-faint); }
.board-search:focus{ border-color: var(--flame-1); outline: none; }

.board-list{ border-top: 1px solid var(--line); }
.board-row{
  display: grid; grid-template-columns: 110px 1fr auto; align-items: center; gap: 18px;
  padding: 16px 6px; border-bottom: 1px solid var(--line);
  cursor: pointer; background: transparent; transition: background .15s ease;
}
.board-row:hover{ background: var(--bg-panel); }
.board-row .date{ font-family: var(--font-mono); color: var(--flame-2); font-size: 0.85rem; }
.board-row .title{ color: var(--text); font-size: 0.98rem; }
.badge{
  font-family: var(--font-mono); font-size: 0.75rem; color: var(--text-faint);
  border: 1px solid var(--line); border-radius: var(--radius); padding: 2px 8px; white-space: nowrap;
  display: inline-block;
}
.board-row .badge{ justify-self: end; }
.pub-title .badge{ margin-left: 8px; vertical-align: middle; color: var(--flame-2); border-color: var(--flame-1); }
.board-empty{ color: var(--text-dim); padding: 32px 0; text-align: center; }

.board-pagination{
  display: flex; justify-content: center; gap: 6px; margin-top: 28px; flex-wrap: wrap;
}
.board-page-btn{
  font-family: var(--font-mono); font-size: 0.85rem;
  min-width: 34px; padding: 6px 10px; border: 1px solid var(--line); border-radius: var(--radius);
  background: transparent; color: var(--text-dim); cursor: pointer;
}
.board-page-btn:hover{ color: var(--text); border-color: var(--flame-1); }
.board-page-btn.active{ color: var(--on-accent); background: var(--flame-grad); border-color: transparent; }
.board-page-btn:disabled{ opacity: 0.35; cursor: default; }

@media (max-width: 640px){
  .board-row{ grid-template-columns: 1fr; gap: 4px; }
  .board-row .badge{ justify-self: start; }
}

/* Modal (detail view) */
.board-modal{
  position: fixed; inset: 0; z-index: 200; display: none;
}
.board-modal.open{ display: block; }
.board-modal-backdrop{
  position: absolute; inset: 0; background: rgba(8,10,14,0.75); backdrop-filter: blur(2px);
}
.board-modal-content{
  position: relative; z-index: 1;
  max-width: 720px; margin: 6vh auto; max-height: 88vh; overflow-y: auto;
  background: var(--bg-panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 32px;
}
.board-modal-close{
  position: absolute; top: 16px; right: 16px;
  background: transparent; border: 1px solid var(--line); color: var(--text-dim);
  border-radius: var(--radius); width: 32px; height: 32px; cursor: pointer; font-size: 1rem;
}
.board-modal-close:hover{ color: var(--text); border-color: var(--flame-1); }
.board-modal-body .date{ font-family: var(--font-mono); color: var(--flame-2); font-size: 0.85rem; }
.board-modal-body h3{ font-size: 1.3rem; margin: 10px 0 18px; }
.board-modal-body .content-block{ color: var(--text-dim); white-space: pre-line; margin: 0 0 20px; }
.board-modal-gallery{
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px,1fr)); gap: 10px;
  margin-bottom: 20px;
}
.board-modal-gallery img{
  border-radius: var(--radius); border: 1px solid var(--line);
  aspect-ratio: 4/3; object-fit: cover; background: var(--bg);
}
.board-modal-gallery img.portrait{ aspect-ratio: 3/4; }
.board-modal-gallery.large{ grid-template-columns: 1fr; }
.board-modal-gallery.large img{
  aspect-ratio: 16/9; width: 100%; max-height: 70vh;
  object-fit: cover; background: var(--bg);
}
.board-modal-gallery.large img.portrait{
  aspect-ratio: 3/4; width: auto; max-width: 100%; max-height: 70vh;
  display: block; margin: 0 auto; object-fit: cover;
}
@media (max-width: 640px){
  .board-modal-content{ margin: 0; max-height: 100vh; border-radius: 0; }
}

/* ---------- Members ---------- */
.member-group-title{
  font-family: var(--font-mono); font-size: 0.85rem; letter-spacing: 0.06em;
  color: var(--text-dim); text-transform: uppercase; margin: 40px 0 16px;
  border-top: 1px solid var(--line); padding-top: 32px;
}
.member-group-title:first-child{ border-top: none; padding-top: 0; margin-top: 0; }
.member-grid{
  display: grid; grid-template-columns: repeat(auto-fill, minmax(190px,1fr));
  gap: 20px;
}
.member-card{ text-align: left; }
.member-photo{
  width: 100%; aspect-ratio: 3/4; object-fit: cover;
  border-radius: var(--radius); background: var(--bg-panel);
  border: 1px solid var(--line); margin-bottom: 10px;
  transition: transform 0.14s ease;
}
.member-photo.photo-flip{ transform: scaleX(0); }
.member-card h3{ font-size: 1rem; margin-bottom: 2px; }
.member-card .role{ color: var(--flame-2); font-size: 0.82rem; font-family: var(--font-mono); }
.member-card .en{ color: var(--text-faint); font-size: 0.85rem; }
.member-card .email{ font-size: 0.82rem; margin-top: 6px; }
.member-card .research{
  font-size: 0.82rem; color: var(--text-faint); margin-top: 6px;
  padding-top: 6px; border-top: 1px dashed var(--line);
}

.prof-card{
  display: grid; grid-template-columns: 200px 1fr; gap: 28px;
  background: var(--bg-panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; margin-bottom: 8px;
}
.prof-card .member-photo{ aspect-ratio: 3/4; margin-bottom: 0; }
.prof-card .bio{ color: var(--text-dim); margin-top: 10px; font-size: 0.95rem; }
.prof-detail{ margin-top: 20px; }
.prof-detail h4{
  font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.08em;
  color: var(--flame-2); text-transform: uppercase; margin-bottom: 8px;
}
.prof-list{ list-style: none; margin: 0; padding: 0; }
.prof-list li{
  position: relative; padding-left: 14px; margin-bottom: 5px;
  color: var(--text-dim); font-size: 0.9rem; line-height: 1.5;
}
.prof-list li::before{
  content: "–"; position: absolute; left: 0; color: var(--text-faint);
}
.prof-list li.highlight{ color: var(--text); font-weight: 600; }
.prof-list li.highlight::before{ color: var(--flame-2); }
@media (max-width: 600px){
  .prof-card{ grid-template-columns: 140px 1fr; }
}

/* ---------- Publications ---------- */
.pub-tabs{ display:flex; gap: 8px; flex-wrap: wrap; margin-bottom: 28px; }
.pub-tab{
  font-family: var(--font-mono); font-size: 0.82rem;
  padding: 8px 14px; border: 1px solid var(--line); border-radius: var(--radius);
  color: var(--text-dim); cursor: pointer; background: transparent;
}
.pub-tab.active, .pub-tab:hover{ color: var(--text); border-color: var(--flame-2); }

.pub-list{ list-style: none; padding: 0; margin: 0; }
.pub-list li{
  display: grid; grid-template-columns: 70px 1fr; gap: 18px;
  padding: 16px 0; border-bottom: 1px solid var(--line);
}
.pub-list li:last-child{ border-bottom: none; }
.pub-year{ font-family: var(--font-mono); color: var(--flame-2); font-size: 0.95rem; }
.pub-title{ color: var(--text); }
.pub-title a{ color: var(--text); text-decoration: none; }
.pub-title a:hover{ color: var(--telemetry); text-decoration: underline; }
.pub-title-kr{ display: inline; }
.pub-title-en{ display: block; }
.pub-title-en{ color: var(--text-dim); font-size: 0.9rem; margin-top: 2px; }
.pub-meta{ color: var(--text-dim); font-size: 0.88rem; margin-top: 4px; }
.pub-meta-line{ margin-top: 2px; }
.pub-url, .pub-doi{ color: var(--telemetry); }
.pub-group{ margin-bottom: 44px; }
.pub-group h3{
  font-family: var(--font-mono); font-size: 0.85rem; letter-spacing: 0.06em;
  color: var(--text-dim); text-transform: uppercase; margin-bottom: 4px;
}

/* ---------- Projects ---------- */
.project-list{
  display: grid;
  gap: 18px;
}
.project-item{
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 28px;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}
.project-item:first-child{ padding-top: 0; }
.project-item:last-child{ border-bottom: none; padding-bottom: 0; }
.project-period{
  font-family: var(--font-mono);
  color: var(--flame-2);
  font-size: 0.95rem;
  white-space: nowrap;
}
.project-body h3{
  margin: 0 0 10px;
  font-size: 1.15rem;
  line-height: 1.45;
}
.project-meta{
  display: grid;
  gap: 4px;
  color: var(--text-dim);
  font-size: 0.92rem;
}
.project-keywords{
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}
.project-keywords span{
  display: inline-flex;
  align-items: center;
  border: 1px solid rgba(56, 189, 248, 0.45);
  color: var(--telemetry);
  border-radius: 999px;
  padding: 3px 9px;
  font-size: 0.78rem;
  line-height: 1.5;
}
@media (max-width: 760px){
  .project-item{
    grid-template-columns: 1fr;
    gap: 8px;
  }
}

/* ---------- Contact ---------- */
.contact-grid{
  display: grid; grid-template-columns: 1fr 1fr; gap: 40px;
}
.contact-info dt{
  font-family: var(--font-mono); font-size: 0.78rem; color: var(--flame-2);
  text-transform: uppercase; letter-spacing: 0.06em; margin-top: 20px;
}
.contact-info dt:first-child{ margin-top: 0; }
.contact-info dd{ margin: 4px 0 0; color: var(--text-dim); }
.map-embed{
  border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
  min-height: 320px;
}
.map-embed iframe{ width: 100%; height: 100%; min-height: 320px; border: 0; }
.recruit-box{
  background: var(--bg-panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; margin-top: 28px;
}
@media (max-width: 760px){
  .contact-grid{ grid-template-columns: 1fr; }
}

/* ---------- Footer ---------- */
.site-footer{
  padding: 32px 0; text-align: center; color: var(--text-faint); font-size: 0.85rem;
}
.site-footer .lab-line{ color: var(--text-dim); margin-bottom: 6px; }