/* =============================================
   RECON Paper Website — style.css
   ============================================= */

:root {
  --bg: #fafaf8;
  --bg-alt: #f4f4f0;
  --text: #1a1a1a;
  --text-muted: #555550;
  --accent: #1a56db;
  --accent-hover: #1340ad;
  --accent-light: #eef3ff;
  --green: #0e7f6b;
  --green-light: #edf7f5;
  --red: #c0392b;
  --red-light: #fdf0ee;
  --code-bg: #f0f0ec;
  --border: #e2e2de;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}

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

html {
  scroll-behavior: smooth;
  font-size: 17px;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ---- Container ---- */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---- Nav ---- */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 248, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 4px;
  height: 48px;
  overflow-x: auto;
  scrollbar-width: none;
}

.nav-inner::-webkit-scrollbar { display: none; }

.nav-inner a {
  white-space: nowrap;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  padding: 4px 10px;
  border-radius: 6px;
  transition: background 0.15s, color 0.15s;
}

.nav-inner a:hover {
  background: var(--accent-light);
  color: var(--accent);
}

/* ---- Hero ---- */
#hero {
  padding: 80px 0 64px;
  text-align: center;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}

.venue-badge {
  display: inline-block;
  background: var(--accent-light);
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 4px 14px;
  border-radius: 999px;
  margin-bottom: 24px;
}

.paper-title {
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.2;
  max-width: 720px;
  margin: 0 auto 24px;
  color: var(--text);
}

.paper-title .method {
  color: var(--accent);
}

.authors {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.authors sup {
  font-size: 11px;
  color: var(--accent);
}

.authors a {
  color: var(--text-muted);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: color 0.15s, border-color 0.15s;
}

.authors a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.equal-note {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.affiliation {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  padding-top: 14px;
  margin-bottom: 28px;
}


.action-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.hero-tldr {
  font-size: 15px;
  color: var(--text-muted);
  max-width: 720px;
  margin: 0 auto;
  line-height: 1.5;
  font-style: italic;
}

.btn {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  padding: 9px 22px;
  border-radius: 8px;
  text-decoration: none;
  transition: background 0.15s, color 0.15s, border-color 0.15s, box-shadow 0.15s;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  border: 1.5px solid var(--accent);
}

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

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

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

.btn-disabled {
  opacity: 0.5;
  cursor: default;
  pointer-events: none;
}

/* ---- Section base ---- */
section {
  padding: 72px 0;
}

section:nth-of-type(even) {
  background: var(--bg-alt);
}

section h2 {
  font-size: 1.65rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  color: var(--text);
}

section p {
  margin-bottom: 16px;
  color: var(--text);
}

.subsection-header {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-top: 52px;
  margin-bottom: 16px;
  color: var(--text);
}

section p:last-child {
  margin-bottom: 0;
}

/* ---- Abstract ---- */
.tldr-box {
  border-left: 4px solid var(--accent);
  background: var(--accent-light);
  padding: 16px 20px;
  border-radius: 0 8px 8px 0;
  margin-bottom: 24px;
  font-size: 1.02rem;
  line-height: 1.65;
}

.tldr-label {
  font-weight: 700;
  color: var(--accent);
  margin-right: 8px;
}

.abstract-text {
  font-size: 0.97rem;
  color: var(--text-muted);
  line-height: 1.75;
}

/* ---- Figures ---- */
.figure-block {
  margin: 40px 0 0;
  text-align: center;
}

.figure-block img {
  max-width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: var(--shadow);
  display: block;
  margin: 0 auto;
}

.figure-padded img {
  background: #fff;
  padding: 12px;
}

.figure-block figcaption {
  margin-top: 14px;
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.55;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}

.figure-medium img {
  max-width: 680px;
}

/* ---- Concept grid (method) ---- */
.concept-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 28px 0;
}

.concept-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 22px;
}

.concept-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text);
}

.concept-card p {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.6;
}

/* ---- Variant cards ---- */
.variant-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 8px 0 32px;
}

.variant-card {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  background: var(--bg);
}

.variant-select {
  border-left: 4px solid var(--accent);
}

.variant-grpo {
  border-left: 4px solid var(--green);
}

.variant-label {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  margin-bottom: 8px;
}

.variant-select .variant-label { color: var(--accent); }
.variant-grpo .variant-label { color: var(--green); }

.variant-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.6;
}

/* ---- Stats row ---- */
.stats-row {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.stat-card {
  flex: 1 1 0;
  min-width: 180px;
  border-radius: 12px;
  padding: 28px 20px;
  text-align: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  border: 1px solid var(--border);
  background: var(--bg);
}

.stat-number {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1;
  margin-bottom: 10px;
}

.stat-label {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.45;
}

.stat-card-blue .stat-number  { color: var(--accent); }
.stat-card-green .stat-number { color: var(--green); }
.stat-card-red .stat-number   { color: var(--red); }

.stat-card-blue  { background: var(--accent-light); border-color: #c5d8ff; }
.stat-card-green { background: var(--green-light);  border-color: #b3e4dc; }
.stat-card-red   { background: var(--red-light);    border-color: #f5c6c2; }

.stats-note {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 0 !important;
}

/* ---- BibTeX ---- */
.bibtex-wrapper {
  position: relative;
  margin-top: 20px;
}

.bibtex-block {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
  padding-right: 80px;
  font-family: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
  font-size: 13px;
  line-height: 1.65;
  overflow-x: auto;
  white-space: pre;
  color: var(--text);
}

.copy-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: 6px;
  padding: 5px 12px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}

.copy-btn:hover {
  background: var(--accent-light);
  border-color: var(--accent);
}

/* ---- Footer ---- */
footer {
  padding: 40px 0;
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  text-align: center;
}

footer p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 6px;
}

footer p:last-child { margin-bottom: 0; }

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

footer a:hover { text-decoration: underline; }

/* ---- Responsive ---- */
@media (max-width: 768px) {
  html { font-size: 16px; }

  section { padding: 52px 0; }

  #hero { padding: 56px 0 44px; }

  .paper-title { font-size: 1.8rem; }

  .concept-grid,
  .variant-grid { grid-template-columns: 1fr; }

  .stat-number { font-size: 2.4rem; }

  .stat-card { flex: 1 1 100%; }
}

@media (max-width: 480px) {
  .paper-title { font-size: 1.5rem; }

  #hero { padding: 44px 0 36px; }

  .stat-number { font-size: 2rem; }
}