/* ── Design tokens ── */
:root {
  --yellow:  #FFD700;
  --green:   #34C759;
  --blue:    #007AFF;
  --pink:    #FF2D55;
  --orange:  #FF9500;
  --purple:  #AF52DE;
  --red:     #FF3B30;
  --unknown: #8E8E93;

  --bg:      #F0F2F5;
  --surface: #FFFFFF;
  --border:  #E5E5EA;
  --text:    #1C1C1E;
  --muted:   #636366;
  --accent:  #007AFF;

  --word-blue:       #2B579A;
  --obsidian-purple: #7C5CBF;
  --error-bg:        #FFF2F2;
  --error-border:    #FFCDD2;
  --error-text:      #C62828;

  --radius:    12px;
  --shadow:    0 1px 4px rgba(0,0,0,0.07);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.10);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

/* ── Header ── */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(0,0,0,0.04);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 11px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo { display: flex; align-items: center; gap: 12px; }
.logo-img { width: 36px; height: 36px; object-fit: contain; }
.logo h1 { font-size: 1.1rem; font-weight: 700; letter-spacing: -0.3px; }
.tagline { font-size: 0.72rem; color: var(--muted); margin-top: 1px; }
.header-free-badge {
  font-size: 0.72rem; font-weight: 600;
  background: #E8F5E9; color: #2e7d32;
  border: 1px solid #c8e6c9;
  border-radius: 20px; padding: 3px 10px;
  white-space: nowrap;
}

/* ── Error banner ── */
.error-banner {
  background: var(--error-bg);
  border-bottom: 1px solid var(--error-border);
  color: var(--error-text);
  font-size: 0.88rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 20px;
  gap: 12px;
}
.error-close {
  background: none; border: none; cursor: pointer;
  color: var(--error-text); font-size: 1rem; padding: 0 4px;
  flex-shrink: 0;
}

/* ── Drop zone ── */
#main {
  max-width: 520px;
  margin: 64px auto;
  padding: 0 20px;
}

/* Full-page drag overlay */
.page-drag-overlay {
  position: fixed; inset: 0; z-index: 50;
  background: rgba(0,122,255,0.06);
  border: 3px dashed var(--accent);
  border-radius: var(--radius);
  pointer-events: none;
}

.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 52px 28px 44px;
  text-align: center;
  cursor: pointer;
  outline: none;
  transition: border-color 0.18s, background 0.18s, box-shadow 0.18s;
  box-shadow: var(--shadow);
}
.drop-zone:hover, .drop-zone:focus, .drop-zone.drag-over {
  border-color: var(--accent);
  background: #F0F6FF;
  box-shadow: 0 0 0 4px rgba(0,122,255,0.08);
}

.drop-logo  {
  width: 72px; height: 72px; object-fit: contain; margin-bottom: 18px;
  filter: drop-shadow(0 4px 8px rgba(0,0,0,0.12));
}
.drop-title { font-size: 1.15rem; font-weight: 700; margin-bottom: 6px; letter-spacing: -0.2px; }
.drop-sub   { font-size: 0.88rem; color: var(--muted); }
.browse-link { color: var(--accent); text-decoration: underline; cursor: pointer; }
.drop-hint  { font-size: 0.74rem; color: var(--muted); margin-top: 10px; }

/* ── Trust strip ── */
.trust-strip {
  display: flex; align-items: center; justify-content: center;
  gap: 8px; flex-wrap: wrap; margin-top: 18px;
}
.trust-badge {
  font-size: 0.75rem; font-weight: 600; color: #2e7d32;
}
.trust-sep { color: var(--border); font-size: 0.85rem; }

/* ── Loading ── */
.loading {
  position: fixed; inset: 0;
  background: rgba(255,255,255,0.94);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 14px; z-index: 200;
  font-size: 0.88rem; color: var(--muted);
}
.loading-logo {
  width: 52px; height: 52px; object-fit: contain;
  opacity: 0.65;
}
.spinner {
  width: 28px; height: 28px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.75s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Results ── */
.results {
  max-width: 1100px;
  margin: 0 auto;
  padding: 20px 20px 60px;
}

/* ── PDF info card ── */
.pdf-card {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  background: var(--surface);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-md);
}
.pdf-thumb-col { flex-shrink: 0; }
.pdf-thumb {
  width: 110px;
  border-radius: 6px;
  box-shadow: 0 0 0 1px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.15);
  display: block;
}
.pdf-thumb-ph {
  width: 110px; height: 142px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  font-size: 2.2rem;
}
.pdf-info { flex: 1; min-width: 0; }
.info-filename {
  font-size: 0.98rem; font-weight: 700; margin-bottom: 3px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.info-sub {
  font-size: 0.81rem; color: var(--muted); margin-bottom: 2px;
}
.copy-bar {
  display: flex; gap: 10px; flex-wrap: wrap;
  align-items: center; margin-top: 16px;
}
.copy-feedback {
  font-size: 0.8rem; font-weight: 600; color: #1a7a40;
  margin-top: 10px;
}

/* ── DOI row ── */
.doi-row {
  display: flex; align-items: center; gap: 8px;
  margin-top: 10px; flex-wrap: wrap;
}
.doi-label {
  font-size: 0.72rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.5px; color: var(--muted); flex-shrink: 0;
}
.doi-value {
  font-size: 0.8rem; color: var(--muted);
  word-break: break-all; flex: 1;
}
.btn-bibtex {
  background: #1a7a40; color: white; flex-shrink: 0;
}
.btn-bibtex:hover:not(:disabled) { filter: brightness(1.1); }

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 16px; border-radius: 8px;
  font-size: 0.87rem; font-weight: 600;
  cursor: pointer; border: none;
  transition: filter 0.15s, transform 0.1s;
  white-space: nowrap;
}
.btn:active:not(:disabled) { transform: scale(0.97); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }

.btn-badge {
  display: inline-flex; align-items: center; justify-content: center;
  width: 20px; height: 20px; border-radius: 4px;
  font-size: 0.72rem; font-weight: 900;
  background: rgba(255,255,255,0.28); flex-shrink: 0;
}
.btn-word     { background: var(--word-blue);       color: white; }
.btn-obsidian { background: var(--obsidian-purple);  color: white; }
.btn-word:hover:not(:disabled),
.btn-obsidian:hover:not(:disabled) { filter: brightness(1.1); }

.btn-ghost { background: transparent; color: var(--muted); padding: 6px 12px; }
.btn-ghost:hover:not(:disabled) { color: var(--text); background: var(--bg); }
.btn-sm { padding: 5px 10px; font-size: 0.8rem; }

/* ── Filter bar ── */
.filter-bar {
  display: flex; align-items: center; gap: 8px;
  padding: 12px 0; flex-wrap: wrap;
  border-bottom: 1px solid var(--border);
  margin-bottom: 18px;
}
.count-label { font-size: 0.78rem; color: var(--muted); margin-left: auto; }

/* ── Pills ── */
.pills { display: flex; gap: 6px; flex-wrap: wrap; }

.pill {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 4px 10px; border-radius: 20px;
  border: 1.5px solid var(--border); background: var(--surface);
  cursor: pointer; font-size: 0.78rem; font-weight: 500;
  transition: border-color 0.15s, background 0.15s, color 0.15s;
  white-space: nowrap;
}
.pill:hover { border-color: var(--accent); }
.pill.active {
  background: var(--pill-color, var(--accent));
  border-color: transparent; color: white;
}
.color-dot {
  width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0;
}
.pill.active .color-dot { background: rgba(255,255,255,0.65); }

.pill-count {
  font-size: 0.7rem; opacity: 0.7;
  background: rgba(0,0,0,0.08);
  border-radius: 10px; padding: 0 5px;
  min-width: 18px; text-align: center;
}
.pill.active .pill-count { background: rgba(255,255,255,0.25); }

/* ── Inputs ── */
.select {
  padding: 6px 10px;
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--surface); color: var(--text);
  font-size: 0.85rem; cursor: pointer;
}
.select:focus { outline: none; border-color: var(--accent); }
.select-sm { padding: 4px 8px; font-size: 0.8rem; }

.search-wrap { flex: 1; min-width: 130px; max-width: 240px; }
.search-input {
  width: 100%; padding: 5px 10px;
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--surface); color: var(--text); font-size: 0.85rem;
}
.search-input:focus { outline: none; border-color: var(--accent); }

/* ── Cards ── */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 12px;
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}
.card {
  background: var(--surface); border-radius: var(--radius);
  box-shadow: var(--shadow); overflow: hidden;
  transition: box-shadow 0.18s, transform 0.18s;
  animation: fadeUp 0.22s ease both;
}
.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.card-header {
  padding: 9px 14px; border-left: 4px solid #ccc;
  display: flex; align-items: center; gap: 8px;
  flex-wrap: wrap; background: var(--bg);
}
.color-dot-sm {
  width: 9px; height: 9px; border-radius: 50%; flex-shrink: 0;
}
.card-type {
  font-size: 0.72rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.5px;
}
.card-page {
  margin-left: auto; font-size: 0.75rem; color: var(--muted); white-space: nowrap;
}
.card-section { font-size: 0.7rem; color: var(--muted); width: 100%; margin-top: 1px; }
.card-body {
  padding: 10px 14px 14px; font-size: 0.9rem;
  line-height: 1.6; white-space: pre-wrap;
}

/* ── No-results / empty state ── */
.no-results {
  text-align: center; color: var(--muted);
  padding: 48px 0; font-size: 0.9rem;
}
.empty-state {
  display: flex; flex-direction: column;
  align-items: center; text-align: center;
  padding: 48px 20px; gap: 14px;
}
.empty-logo { width: 80px; height: 80px; object-fit: contain; opacity: 0.5; }
.empty-state h3 { font-size: 1.05rem; color: var(--text); }
.empty-state p  { font-size: 0.87rem; color: var(--muted); line-height: 1.6; }

/* ── Utility ── */
.hidden { display: none !important; }

/* ── Responsive ── */
@media (max-width: 580px) {
  .pdf-card { flex-direction: column; }
  .pdf-thumb, .pdf-thumb-ph { width: 80px; }
  .pdf-thumb-ph { height: 104px; font-size: 1.8rem; }
  .cards { grid-template-columns: 1fr; }
  .copy-bar { flex-direction: column; align-items: stretch; }
  .copy-bar .btn { justify-content: center; }
  .search-wrap { max-width: none; }
  .header-free-badge { display: none; }
}