/* ─── Reader Page Design System ─── */
/* Matches index.html: warm dark academic palette */

:root {
  --bg: #191a21;
  --bg-warm: #1e1f28;
  --surface: #232430;
  --surface-raised: #2a2b38;
  --border: rgba(255, 255, 255, 0.07);
  --border-strong: rgba(255, 255, 255, 0.12);
  --text: #d4d2cc;
  --text-bright: #eae8e3;
  --text-dim: #8a8880;
  --text-muted: #5e5d57;
  --accent: #c9a84c;
  --accent-soft: #b89a47;
  --accent-glow: rgba(201, 168, 76, 0.08);
  --teal: #5a9e8f;
  --teal-dim: rgba(90, 158, 143, 0.12);
  --warm-white: #f0ece4;
  --serif: 'Libre Baskerville', 'Georgia', serif;
  --sans: 'Source Sans 3', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  font-weight: 400;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ─── Grain overlay ─── */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 9999;
}

/* ─── Sticky Nav ─── */
.reader-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.5rem;
  background: rgba(25, 26, 33, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.reader-nav a {
  color: var(--text-dim);
  text-decoration: none;
  font-size: 0.85rem;
  font-family: var(--sans);
  transition: color 0.2s;
}

.reader-nav a:hover {
  color: var(--accent);
}

.reader-nav .btn-pdf {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  color: var(--text);
  font-size: 0.8rem;
  text-decoration: none;
  transition: all 0.2s;
}

.reader-nav .btn-pdf:hover {
  background: var(--surface-raised);
  border-color: var(--accent);
  color: var(--accent);
}

/* ─── Paper Header ─── */
.paper-header {
  max-width: 720px;
  margin: 0 auto;
  padding: 4rem 1.5rem 2rem;
  border-bottom: 1px solid var(--border);
}

.paper-meta {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
}

.paper-header h1 {
  font-family: var(--serif);
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-bright);
  line-height: 1.3;
  margin-bottom: 1.5rem;
}

.paper-authors {
  font-size: 0.95rem;
  color: var(--text-dim);
  margin-bottom: 0.5rem;
}

.paper-affiliation {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-style: italic;
}

.paper-doi {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 1rem;
}

/* ─── Abstract ─── */
.abstract {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.abstract h2 {
  font-family: var(--serif);
  font-size: 1.1rem;
  color: var(--accent);
  margin-bottom: 1rem;
  font-weight: 700;
}

.abstract p {
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--text);
}

/* ─── Main Content ─── */
.paper-content {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

/* Sections */
.paper-content h1 {
  font-family: var(--serif);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--accent);
  margin: 3rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.paper-content h2 {
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-bright);
  margin: 2.5rem 0 0.75rem;
}

.paper-content h3 {
  font-family: var(--serif);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-bright);
  margin: 2rem 0 0.5rem;
}

.paper-content h4 {
  font-family: var(--sans);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  margin: 1.5rem 0 0.5rem;
}

/* Paragraphs */
.paper-content p {
  margin-bottom: 1rem;
  font-size: 0.95rem;
}

/* Lists */
.paper-content ul, .paper-content ol {
  margin: 0.75rem 0 1rem 1.5rem;
  font-size: 0.95rem;
}

.paper-content li {
  margin-bottom: 0.4rem;
}

/* Links */
.paper-content a {
  color: var(--teal);
  text-decoration: none;
  border-bottom: 1px solid var(--teal-dim);
  transition: all 0.2s;
}

.paper-content a:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* ─── Theorem-like blocks ─── */
.paper-content .theorem,
.paper-content .proposition,
.paper-content .lemma,
.paper-content .corollary,
.paper-content .axiom,
.paper-content .assumption {
  background: var(--surface);
  border-left: 3px solid var(--accent);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  border-radius: 0 4px 4px 0;
}

.paper-content .definition {
  background: var(--surface);
  border-left: 3px solid var(--teal);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  border-radius: 0 4px 4px 0;
}

.paper-content .remark,
.paper-content .example {
  background: var(--accent-glow);
  border-left: 3px solid var(--text-muted);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  border-radius: 0 4px 4px 0;
}

.paper-content .proof {
  padding: 0.75rem 0;
  margin: 1rem 0;
  border-bottom: 1px solid var(--border);
}

.paper-content .proof > p:first-child::before {
  content: "Proof. ";
  font-style: italic;
  font-weight: 600;
  color: var(--text-dim);
}

/* QED square */
.paper-content .proof::after {
  content: "□";
  display: block;
  text-align: right;
  color: var(--text-muted);
  margin-top: 0.5rem;
}

/* ─── Pseudocode / Algorithm ─── */
.paper-content .algorithm {
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  margin: 1.5rem 0;
  overflow-x: auto;
}

.paper-content .algorithmic {
  padding: 1rem 1.25rem;
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.9;
}

.paper-content .algo-line {
  white-space: nowrap;
  position: relative;
}

.paper-content .algo-num {
  display: inline-block;
  width: 28px;
  color: var(--text-muted);
  font-size: 0.7rem;
  text-align: right;
  margin-right: 12px;
  user-select: none;
  opacity: 0.6;
}

.paper-content .algo-line .kw {
  color: var(--accent);
  font-weight: 500;
}

.paper-content .algo-line .comment {
  color: var(--text-muted);
  font-style: italic;
}

/* ─── Tables ─── */
.paper-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.85rem;
}

.paper-content thead th {
  font-family: var(--sans);
  font-weight: 600;
  color: var(--text-bright);
  padding: 0.6rem 0.75rem;
  border-bottom: 2px solid var(--accent);
  text-align: left;
}

.paper-content tbody td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--border);
}

.paper-content tbody tr:nth-child(even) {
  background: var(--surface);
}

.paper-content caption {
  font-size: 0.8rem;
  color: var(--text-dim);
  text-align: left;
  margin-bottom: 0.5rem;
  font-style: italic;
}

/* ─── Math display blocks ─── */
.paper-content .math.display {
  overflow-x: auto;
  padding: 0.5rem 0;
  margin: 1rem 0;
}

/* ─── Blockquotes ─── */
.paper-content blockquote {
  border-left: 3px solid var(--accent-soft);
  padding: 0.75rem 1.25rem;
  margin: 1.5rem 0;
  font-style: italic;
  color: var(--text-dim);
  background: var(--accent-glow);
  border-radius: 0 4px 4px 0;
}

/* ─── Code ─── */
.paper-content code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--surface);
  padding: 0.15em 0.35em;
  border-radius: 3px;
  color: var(--teal);
}

.paper-content pre {
  background: var(--surface);
  padding: 1rem;
  border-radius: 4px;
  overflow-x: auto;
  margin: 1rem 0;
  border: 1px solid var(--border);
}

.paper-content pre code {
  background: none;
  padding: 0;
}

/* ─── Footnotes ─── */
.paper-content .footnotes {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-dim);
}

/* ─── References section ─── */
.paper-content #references,
.paper-content #bibliography {
  margin-top: 3rem;
}

.paper-content #references + .references,
.paper-content .references {
  font-size: 0.85rem;
  line-height: 1.7;
}

.paper-content .references p,
.paper-content .csl-entry {
  padding-left: 2rem;
  text-indent: -2rem;
  margin-bottom: 0.6rem;
}

/* ─── Figure captions ─── */
.paper-content figcaption,
.paper-content .caption {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-style: italic;
  margin-top: 0.5rem;
}

/* ─── Horizontal rules ─── */
.paper-content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}

/* ─── Footer ─── */
.reader-footer {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

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

/* ─── Mobile ─── */
@media (max-width: 768px) {
  .paper-header {
    padding: 3rem 1rem 1.5rem;
  }

  .paper-header h1 {
    font-size: 1.5rem;
  }

  .abstract, .paper-content {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .paper-content h1 {
    font-size: 1.3rem;
  }

  .paper-content h2 {
    font-size: 1.15rem;
  }

  .paper-content table {
    font-size: 0.75rem;
  }

  .paper-content .math.display {
    font-size: 0.85em;
  }

  .reader-nav {
    padding: 0.6rem 1rem;
  }
}

/* ─── Print ─── */
@media print {
  body { background: white; color: #1a1a1a; }
  .reader-nav { display: none; }
  .paper-content a { color: inherit; border: none; }
}