/* ════════════════════════════════════════
   PAPER VIEWER — sidebar + PDF embed
   ════════════════════════════════════════ */

.paper-viewer-page {
  background: var(--bg);
  background-image:
    linear-gradient(to right, color-mix(in srgb, var(--accent) 5.5%, transparent) 1px, transparent 1px),
    linear-gradient(to bottom, color-mix(in srgb, var(--accent) 5.5%, transparent) 1px, transparent 1px),
    var(--noise);
  background-size: 48px 48px, 48px 48px, 200px 200px;
  overflow: hidden;
  height: 100vh;
  height: 100dvh;
}

/* ── LAYOUT ── */
.paper-viewer-layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  height: 100vh;
  height: 100dvh;
}

/* ── SIDEBAR ── */
.paper-sidebar {
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  border-right: 1px solid var(--line);
  overflow-y: auto;
  overflow-x: hidden;
  padding: 0;
  display: flex;
  flex-direction: column;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}

.sidebar-header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  flex-shrink: 0;
}

.sidebar-back {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--ink-3);
  text-decoration: none;
  transition: color var(--dur-fast);
}

.sidebar-back:hover { color: var(--accent); }

.sidebar-back .material-symbols-outlined {
  font-size: 18px;
  width: 18px;
  height: 18px;
}

/* Paper info card */
.sidebar-card {
  padding: 18px 16px;
  border-bottom: 1px solid var(--line);
  flex-shrink: 0;
}

.sidebar-title {
  font-family: "Bricolage Grotesque", "Inter", system-ui, sans-serif;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 2px;
}

.sidebar-author {
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.82rem;
  color: var(--ink-2);
  margin-bottom: 2px;
}

.sidebar-year {
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.72rem;
  color: var(--ink-3);
  margin-bottom: 10px;
}

.sidebar-meta {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 12px;
}

.sidebar-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.72rem;
  color: var(--ink-3);
}

.sidebar-meta-item .material-symbols-outlined {
  font-size: 16px;
  width: 16px;
  height: 16px;
}

.sidebar-download {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.78rem;
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  padding: 9px 14px;
  border-radius: 3px;
  text-decoration: none;
  transition: transform var(--dur-fast), box-shadow var(--dur-fast);
}

.sidebar-download:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.sidebar-download .material-symbols-outlined {
  font-size: 18px;
  width: 18px;
  height: 18px;
}

/* TOC */
.sidebar-toc {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  flex-shrink: 0;
}

.sidebar-toc-title {
  padding: 0 16px 10px;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0;
}

.toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.toc-list li {
  margin: 0;
}

.toc-link {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
  padding: 6px 16px;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--ink-2);
  text-decoration: none;
  transition: background var(--dur-fast), color var(--dur-fast);
  border-left: 2px solid transparent;
}

.toc-link:hover {
  background: var(--bg-2);
  color: var(--accent);
}

.toc-link.active {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 4%, transparent);
  border-left-color: var(--accent);
}

.toc-link span {
  font-size: 0.68rem;
  font-weight: 500;
  color: var(--ink-4);
  white-space: nowrap;
}

.toc-chapter > .toc-link {
  font-weight: 700;
  color: var(--ink);
  padding-top: 10px;
}

.toc-sublist {
  list-style: none;
  margin: 0;
  padding: 0;
}

.toc-sublist .toc-link {
  padding-left: 28px;
  font-size: 0.72rem;
  font-weight: 500;
}

/* Citation guide */
.sidebar-cite {
  padding: 14px 0 24px;
}

.sidebar-cite-title {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0 16px 10px;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0;
}

.sidebar-cite-title .material-symbols-outlined {
  font-size: 16px;
  width: 16px;
  height: 16px;
}

.sidebar-cite-intro {
  padding: 0 16px 10px;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.74rem;
  color: var(--ink-3);
  line-height: 1.55;
  margin: 0;
}

.cite-details {
  margin: 0;
}

.cite-details[open] {
  margin-bottom: 8px;
}

.cite-details summary {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  cursor: pointer;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.74rem;
  font-weight: 600;
  color: var(--ink-2);
  list-style: none;
  transition: background var(--dur-fast), color var(--dur-fast);
}

.cite-details summary::-webkit-details-marker { display: none; }

.cite-details summary::after {
  content: "+";
  display: grid;
  place-items: center;
  width: 20px;
  height: 20px;
  border-radius: var(--r-full);
  border: 1px solid var(--line);
  color: var(--ink-3);
  background: var(--bg-2);
  flex-shrink: 0;
  font-size: 0.8rem;
  margin-left: auto;
}

.cite-details[open] summary::after { content: "−"; }

.cite-details summary:hover {
  background: var(--bg-2);
  color: var(--accent);
}

.cite-block {
  padding: 0 16px 4px;
}

.cite-block pre {
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 3px;
  padding: 12px;
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 0.72rem;
  line-height: 1.6;
  color: var(--ink-2);
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
  user-select: text;
  margin: 0;
}

/* ── PDF EMBED ── */
.paper-main-viewer {
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
  background:
    linear-gradient(to right, color-mix(in srgb, var(--accent) 4%, transparent) 1px, transparent 1px),
    linear-gradient(to bottom, color-mix(in srgb, var(--accent) 4%, transparent) 1px, transparent 1px),
    var(--bg-2);
  background-size: 48px 48px, 48px 48px;
}

.paper-embed {
  width: 100%;
  height: 100%;
  border: none;
}

/* ── SIDEBAR TOGGLE (mobile) ── */
.sidebar-toggle {
  display: none;
  position: fixed;
  bottom: 20px;
  left: 20px;
  width: 48px;
  height: 48px;
  border-radius: var(--r-full);
  background: var(--accent);
  color: #fff;
  border: none;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  z-index: 200;
  grid: place-items;
}

.sidebar-toggle .material-symbols-outlined {
  font-size: 24px;
  width: 24px;
  height: 24px;
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 140;
}

.sidebar-overlay.active {
  display: block;
}

/* ── PRINT ── */
@media print {
  .paper-sidebar, .sidebar-toggle { display: none !important; }
  .paper-viewer-layout { grid-template-columns: 1fr; }
  .paper-viewer-page { overflow: auto; }
}

/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  .paper-viewer-layout {
    grid-template-columns: 1fr;
  }

  .paper-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: min(340px, 90vw);
    z-index: 150;
    transform: translateX(-100%);
    transition: transform 300ms var(--ease-out);
    box-shadow: var(--shadow-xl);
  }

  .paper-sidebar.open {
    transform: translateX(0);
  }

  .sidebar-toggle {
    display: grid;
  }
}