*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #080F1A;
  --bg-mid: #0D1724;
  --bg-surface: #111E2E;
  --text: #F0EDE6;
  --text-muted: #7A8B9A;
  --text-dim: #3A4D5E;
  --accent: #2DCCB4;
  --accent-dim: #1A7A6B;
  --accent-faint: rgba(45, 204, 180, 0.08);
  --amber: #C4832A;
  --amber-bg: rgba(196, 131, 42, 0.12);
  --rule: rgba(45, 204, 180, 0.18);
  --rule-quiet: rgba(240, 237, 230, 0.07);
  --serif: 'IBM Plex Serif', Georgia, serif;
  --sans: 'IBM Plex Sans', system-ui, sans-serif;
  --mono: 'IBM Plex Mono', monospace;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  font-weight: 300;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

/* NAV (shared) */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 3rem;
  height: 56px;
  background: rgba(8, 15, 26, 0.94);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--rule-quiet);
}

.nav-left { display: flex; align-items: center; gap: 2.5rem; }

.wordmark {
  font-family: var(--serif);
  font-size: 0.95rem;
  font-weight: 400;
  letter-spacing: 0.01em;
  color: var(--text);
  text-decoration: none;
}
.wordmark span { color: var(--accent); }

.nav-links { display: flex; gap: 2rem; list-style: none; }

.nav-links a {
  font-size: 0.78rem;
  font-weight: 400;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}
.nav-links a:hover { color: var(--text); }
.nav-links a.active { color: var(--accent); }

/* BREADCRUMB */
.breadcrumb {
  max-width: 1180px;
  margin: 0 auto;
  padding: 1.5rem 3rem 0;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.breadcrumb a { color: var(--text-muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb .sep { color: var(--text-dim); }
.breadcrumb .current { color: var(--text-muted); }

/* PAPER HEADER */
.paper-header {
  max-width: 1180px;
  margin: 0 auto;
  padding: 2rem 3rem 2.5rem;
  border-bottom: 1px solid var(--rule-quiet);
}

.paper-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--mono);
  font-size: 0.65rem;
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-faint);
  border: 1px solid var(--rule);
  padding: 0.3rem 0.7rem;
  border-radius: 2px;
  margin-bottom: 1.5rem;
}

.paper-title {
  font-family: var(--serif);
  font-size: clamp(1.9rem, 3.4vw, 2.7rem);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 0.9rem;
  max-width: 42ch;
}

.paper-subtitle {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-style: italic;
  font-weight: 300;
  color: var(--text-muted);
  line-height: 1.5;
  max-width: 52ch;
  margin-bottom: 1.5rem;
}

.paper-authors {
  font-size: 0.95rem;
  color: var(--text);
  margin-bottom: 0.6rem;
}

.paper-meta-row {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--text-dim);
  letter-spacing: 0.04em;
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}
.paper-meta-row span.hl { color: var(--accent); }

/* BODY GRID */
.paper-body {
  max-width: 1180px;
  margin: 0 auto;
  padding: 3rem 3rem 5rem;
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 4rem;
}

.paper-main {}

.block-label {
  font-family: var(--mono);
  font-size: 0.65rem;
  font-weight: 400;
  letter-spacing: 0.15em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.abstract-text {
  font-family: var(--serif);
  font-size: 1.02rem;
  line-height: 1.85;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.keywords-line {
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.8;
  margin-bottom: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--rule-quiet);
}
.keywords-line strong { color: var(--text-muted); font-weight: 500; }

.toc-list {
  list-style: none;
  counter-reset: toc;
}
.toc-list li {
  display: flex;
  gap: 1rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--rule-quiet);
  font-size: 0.92rem;
  color: var(--text-muted);
}
.toc-list li:last-child { border-bottom: none; }
.toc-num {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--text-dim);
  flex-shrink: 0;
  padding-top: 0.15rem;
}

.related-block {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--rule-quiet);
}
.related-card {
  display: block;
  text-decoration: none;
  padding: 1.1rem 1.3rem;
  border: 1px solid var(--rule-quiet);
  border-radius: 2px;
  transition: background 0.15s, border-color 0.15s;
  margin-top: 0.9rem;
}
.related-card:hover { background: var(--accent-faint); border-color: var(--rule); }
.related-kicker {
  font-family: var(--mono);
  font-size: 0.62rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.4rem;
}
.related-title {
  font-family: var(--serif);
  font-size: 0.98rem;
  color: var(--text);
  line-height: 1.4;
}

/* SIDEBAR */
.paper-sidebar { display: flex; flex-direction: column; gap: 1.75rem; }

.thumb-frame {
  display: block;
  border: 1px solid var(--rule-quiet);
  background: var(--bg-mid);
  padding: 10px;
  transition: border-color 0.15s;
}
.thumb-frame:hover { border-color: var(--rule); }
.thumb-frame img {
  display: block;
  width: 100%;
  height: auto;
  box-shadow: 0 8px 28px rgba(0,0,0,0.45);
}

.btn-download {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  width: 100%;
  background: var(--accent);
  color: #080F1A;
  font-family: var(--sans);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  padding: 0.85rem 1rem;
  text-decoration: none;
  border-radius: 2px;
  transition: background 0.2s;
}
.btn-download:hover { background: #3FDFC8; }

.sidebar-box {
  border: 1px solid var(--rule-quiet);
  padding: 1.25rem 1.4rem;
}
.sidebar-box-label {
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 0.8rem;
}
.sidebar-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.82rem;
  padding: 0.4rem 0;
  color: var(--text-muted);
}
.sidebar-row span:last-child { color: var(--text); font-family: var(--mono); font-size: 0.78rem; }

.cite-box {
  font-family: var(--mono);
  font-size: 0.72rem;
  line-height: 1.7;
  color: var(--text-muted);
  background: var(--bg-mid);
  padding: 0.9rem 1rem;
  border-left: 2px solid var(--accent);
  word-break: break-word;
}

/* PREV/NEXT FOOTER NAV */
.paper-pagenav {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 3rem 4rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}
.pagenav-link {
  display: block;
  text-decoration: none;
  padding: 1.5rem 1.75rem;
  border: 1px solid var(--rule-quiet);
  transition: background 0.15s, border-color 0.15s;
}
.pagenav-link:hover { background: var(--accent-faint); border-color: var(--rule); }
.pagenav-link.next { text-align: right; }
.pagenav-dir {
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 0.5rem;
}
.pagenav-title {
  font-family: var(--serif);
  font-size: 1rem;
  color: var(--text);
}

/* FOOTER */
footer {
  border-top: 1px solid var(--rule-quiet);
  padding: 2rem 3rem;
}
.footer-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.footer-left {
  font-family: var(--serif);
  font-size: 0.8rem;
  font-weight: 300;
  color: var(--text-dim);
}
.footer-links { display: flex; gap: 2rem; }
.footer-links a {
  font-family: var(--mono);
  font-size: 0.6rem;
  color: var(--text-dim);
  text-decoration: none;
  letter-spacing: 0.08em;
  transition: color 0.15s;
}
.footer-links a:hover { color: var(--text-muted); }

/* RESPONSIVE */
@media (max-width: 900px) {
  nav { padding: 0.85rem 1.5rem; height: auto; flex-wrap: wrap; row-gap: 0.6rem; }
  .nav-left { gap: 1.25rem; }
  .nav-links { gap: 1.1rem; flex-wrap: wrap; }
  .nav-links a { font-size: 0.72rem; }
  .breadcrumb { padding: 1.25rem 1.5rem 0; }
  .paper-header { padding: 1.75rem 1.5rem 2rem; }
  .paper-body { padding: 2.5rem 1.5rem 3rem; grid-template-columns: 1fr; gap: 2.5rem; }
  .paper-sidebar { order: -1; flex-direction: row; flex-wrap: wrap; }
  .paper-sidebar > * { flex: 1 1 240px; }
  .paper-pagenav { grid-template-columns: 1fr; padding: 0 1.5rem 3rem; }
  .pagenav-link.next { text-align: left; }
  footer { padding: 1.5rem; }
  .footer-inner { flex-direction: column; gap: 1.25rem; align-items: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}