/*
  Paper kit styles. Colors come from the site theme variables in
  _styles/-theme.scss, so every page follows the visitor's chosen theme.
  Layout is ruled sections and rows; no cards.
*/

/* ---------- reading levels ---------- */
.paper[data-level="public"] [data-levels]:not([data-levels~="public"]),
.paper[data-level="hs"] [data-levels]:not([data-levels~="hs"]),
.paper[data-level="ug"] [data-levels]:not([data-levels~="ug"]),
.paper[data-level="grad"] [data-levels]:not([data-levels~="grad"]),
.paper[data-level="res"] [data-levels]:not([data-levels~="res"]) {
  display: none !important;
}

.paper {
  --paper-rule: var(--light-gray);
  --paper-muted: var(--gray);
  --paper-sticky-top: 0px;
  text-align: left;
}

.paper h1, .paper h2, .paper h3 { text-align: left; }

/* ---------- head ---------- */
.paper-head { padding-bottom: 8px; }

.paper-kicker {
  margin: 0 0 6px;
  font-family: var(--code);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}

.paper-title {
  margin: 0;
  text-align: left;
  font-family: var(--title);
  font-size: clamp(1.6rem, 4.6vw, 2.6rem);
  line-height: 1.15;
  text-wrap: balance;
}

.paper-subtitle {
  margin: 10px 0 0;
  font-size: var(--large);
  color: var(--dark-gray);
  max-width: 60ch;
}

.paper-byline {
  margin: 16px 0 0;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 10px;
}

.paper-affil {
  font-size: 0.85rem;
  color: var(--paper-muted);
}

.paper-sep { color: var(--paper-muted); }

.paper-sources {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  border-top: 1px solid var(--paper-rule);
}

.paper-sources li {
  display: grid;
  grid-template-columns: minmax(0, 11rem) minmax(0, 1fr) auto;
  gap: 4px 14px;
  align-items: baseline;
  padding: 8px 0;
  border-bottom: 1px solid var(--paper-rule);
  margin: 0;
}

.paper-source-venue {
  font-family: var(--code);
  font-size: 0.78rem;
  color: var(--paper-muted);
}

.paper-source-access {
  font-family: var(--code);
  font-size: 0.72rem;
  color: var(--accent);
}

@media (max-width: 640px) {
  .paper-sources li { grid-template-columns: minmax(0, 1fr) auto; }
  .paper-source-venue { grid-column: 1 / -1; }
}

/* ---------- level bar ---------- */
.level-bar {
  position: sticky;
  top: var(--paper-sticky-top);
  z-index: 5;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
  margin: 20px 0 8px;
  padding: 10px 0;
  background: var(--background);
  border-top: 2px solid var(--primary);
  border-bottom: 1px solid var(--paper-rule);
}

.level-bar-label {
  font-family: var(--code);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--paper-muted);
}

.level-options {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border: 1px solid var(--paper-rule);
}

.level-option {
  appearance: none;
  margin: 0;
  padding: 7px 12px;
  border: 0;
  border-right: 1px solid var(--paper-rule);
  background: transparent;
  color: var(--text);
  font: inherit;
  font-family: var(--heading);
  font-size: 0.88rem;
  font-weight: var(--semi-bold);
  line-height: 1.2;
  transition: background var(--transition), color var(--transition);
}

.level-option:last-child { border-right: 0; }
.level-option:hover { color: var(--primary); }

.level-option[aria-checked="true"] {
  background: var(--primary);
  color: var(--background);
}

.level-option:focus-visible,
.share-btn:focus-visible,
.paper-copy:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.level-short { display: none; }

@media (max-width: 560px) {
  .level-bar { gap: 6px; padding: 6px 0; margin-top: 14px; }
  .level-bar-label { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  .level-options { width: 100%; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); }
  .level-option { padding: 8px 2px; font-size: 0.78rem; line-height: 1.15; }
  .level-long { display: none; }
  .level-short { display: inline; }
  .paper-subtitle { font-size: 1rem; }
}

/* ---------- body ---------- */
.paper-body h2 {
  margin: 48px 0 14px;
  font-size: var(--xl);
}

.paper p, .paper li { text-align: left; }

.paper-body h3 { margin: 26px 0 6px; font-size: var(--large); }

.paper-body p,
.paper-body li { max-width: 72ch; }

.paper-body .callout {
  margin: 18px 0;
  padding: 2px 0 2px 16px;
  border-left: 3px solid var(--accent);
}

.paper-body table { font-size: 0.9rem; }

/* ---------- foot: cite + share ---------- */
.paper-foot {
  margin-top: 48px;
  border-top: 2px solid var(--primary);
}

.paper-cite-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-top: 22px;
}

.paper-cite-head h2 { margin: 0; font-size: var(--large); }

.paper-copy {
  appearance: none;
  padding: 6px 12px;
  border: 1px solid var(--primary);
  background: transparent;
  color: var(--primary);
  font: inherit;
  font-size: 0.85rem;
  font-family: var(--heading);
  font-weight: var(--semi-bold);
}

.paper-copy:hover { background: var(--primary); color: var(--background); }

.paper-bibtex {
  margin: 12px 0 0;
  padding: 14px;
  max-height: 16rem;
  overflow: auto;
  background: var(--background-alt);
  border-left: 3px solid var(--paper-rule);
  font-family: var(--code);
  font-size: 0.78rem;
  line-height: 1.5;
  white-space: pre;
}

.paper-credit {
  margin: 26px 0 0;
  font-size: 0.85rem;
  color: var(--paper-muted);
  max-width: 72ch;
}

/* ---------- share bar ---------- */
.share-bar { margin-top: 26px; }
.share-bar-compact { margin-top: 14px; }

.share-heading { margin: 0; font-size: var(--large); }

.share-note {
  margin: 4px 0 0;
  font-size: 0.85rem;
  color: var(--paper-muted);
}

.share-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
}

.share-bar-compact .share-buttons { margin-top: 0; }

.share-btn {
  appearance: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 38px;
  padding: 7px 12px;
  border: 1px solid var(--paper-rule);
  background: transparent;
  color: var(--text);
  font: inherit;
  font-size: 0.85rem;
  text-decoration: none;
  transition: border-color var(--transition), color var(--transition);
}

.share-btn:hover { border-color: var(--primary); color: var(--primary); }
.share-btn i, .share-svg { width: 1em; height: 1em; font-size: 1rem; text-align: center; }

.share-bar-compact .share-btn { min-width: 38px; justify-content: center; padding: 7px 10px; }
.share-bar-compact .share-btn span { display: none; }
.share-bar-compact .share-native span { display: inline; }

.share-status {
  min-height: 1.4em;
  margin: 6px 0 0;
  font-size: 0.85rem;
  color: var(--accent);
}

/* ---------- papers index ---------- */
.paper-index {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  border-top: 1px solid var(--light-gray);
}

.paper-index li {
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  grid-template-rows: auto auto 1fr;
  text-align: left;
  column-gap: 20px;
  row-gap: 4px;
  margin: 0;
  padding: 18px 0;
  border-bottom: 1px solid var(--light-gray);
}

.paper-index li > :not(.paper-index-icon) {
  grid-column: 2;
}

.paper-index .paper-index-icon {
  grid-column: 1;
  grid-row: 1 / span 3;
  align-self: start;
}

.paper-index .paper-index-icon img {
  display: block;
  width: 100%;
  height: auto;
}

@media (max-width: 480px) {
  .paper-index li {
    grid-template-columns: 56px minmax(0, 1fr);
    column-gap: 14px;
  }
}

.paper-index a.paper-index-title {
  font-family: var(--heading);
  font-size: var(--large);
  font-weight: var(--semi-bold);
  text-decoration: none;
}

.paper-index .paper-index-meta {
  font-family: var(--code);
  font-size: 0.78rem;
  color: var(--gray);
}

@media (prefers-reduced-motion: reduce) {
  .paper *, .paper *::before, .paper *::after { transition: none !important; animation: none !important; }
}