:root {
  --bg: #f5f6f8;
  --sidebar-bg: #ffffff;
  --card-bg: #ffffff;
  --border: #e2e4e9;
  --text: #1c1f26;
  --text-muted: #6b7280;
  --accent: #3457d5;
  --accent-bg: #eef1fd;
  --chip-bg: #eef0f4;
  --chip-active-bg: #4b5158;
  --chip-active-text: #ffffff;
  --shadow: 0 1px 2px rgba(20, 20, 30, 0.06), 0 2px 8px rgba(20, 20, 30, 0.04);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
}

.app {
  display: grid;
  grid-template-columns: 300px 1fr;
  min-height: 100vh;
}

/* Sidebar */

.sidebar {
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  padding: 20px 18px 32px;
  overflow-y: auto;
  height: 100vh;
  position: sticky;
  top: 0;
}

.sidebar-header {
  margin-bottom: 22px;
}

.sidebar-header h1 {
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.15;
  margin: 0 0 6px;
  color: var(--accent);
}

.sidebar-header .subtitle {
  font-size: 0.85rem;
  font-weight: 600;
  line-height: 1.35;
  margin: 0 0 8px;
  color: var(--text);
}

.sidebar-header .authors {
  font-size: 0.75rem;
  line-height: 1.4;
  margin: 0;
  color: var(--text-muted);
}

.filter-group {
  margin-bottom: 18px;
}

.filter-group > label {
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.search-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
}

.search-row label {
  margin-bottom: 6px;
}

#reset {
  flex: none;
  padding: 3px 9px;
  border: 1px solid var(--border);
  background: transparent;
  border-radius: 999px;
  font-size: 0.72rem;
  cursor: pointer;
  color: var(--text-muted);
}

#reset:hover {
  border-color: var(--accent);
  color: var(--accent);
}

#search {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.9rem;
  background: var(--bg);
}

#search:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.checkbox-row {
  display: flex !important;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 400 !important;
  text-transform: none !important;
  color: var(--text) !important;
  cursor: pointer;
}

/* Year range. The two native range inputs are made fully invisible
   (opacity: 0) and only handle interaction/dragging; every visible pixel
   (track, filled segment, thumbs) is a plain div whose position we compute
   and set ourselves in js/main.js. This sidesteps cross-browser native
   slider thumb styling entirely (recent Chromium versions render their own
   affordance glyph inside a thumb even with -webkit-appearance: none, which
   is what showed up as an unexpected icon before this rewrite). */

.year-range {
  position: relative;
  height: 20px;
  margin-top: 4px;
}

.year-range input[type="range"] {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  opacity: 0;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
  pointer-events: none;
}

.year-range input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  pointer-events: auto;
}

.year-range input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  pointer-events: auto;
  border: none;
}

.year-range .year-track {
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 3px;
  transform: translateY(-50%);
  background: var(--border);
  border-radius: 1.5px;
  pointer-events: none;
}

.year-range .year-range-fill {
  position: absolute;
  top: 50%;
  height: 3px;
  transform: translateY(-50%);
  background: var(--accent);
  border-radius: 1.5px;
  pointer-events: none;
}

.year-range .year-thumb {
  position: absolute;
  top: 50%;
  width: 16px;
  height: 16px;
  margin-left: -8px;
  transform: translateY(-50%);
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid #fff;
  box-shadow: 0 0 0 1px var(--accent);
  pointer-events: none;
}

.year-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 8px;
}

/* Category filter groups (built dynamically) */

.category-group {
  margin-bottom: 16px;
}

.category-group h3 {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-muted);
  margin: 0 0 6px;
}

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  border: 1px solid var(--border);
  background: var(--chip-bg);
  color: var(--text);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 0.78rem;
  cursor: pointer;
  line-height: 1.4;
  user-select: none;
}

.chip:hover {
  border-color: var(--accent);
}

.chip.active {
  background: var(--chip-active-bg);
  border-color: var(--chip-active-bg);
  color: var(--chip-active-text);
}

.chip img {
  width: 14px;
  height: 14px;
  object-fit: contain;
}

/* Main gallery */

main {
  padding: 20px 28px 40px;
  min-width: 0;
}

.results-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.sort-controls {
  display: flex;
  align-items: center;
  gap: 6px;
}

.sort-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.sort-btn {
  border: 1px solid var(--border);
  background: var(--card-bg);
  color: var(--text);
  border-radius: 999px;
  padding: 4px 12px;
  font-size: 0.78rem;
  cursor: pointer;
}

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

.sort-btn.active {
  background: var(--chip-active-bg);
  border-color: var(--chip-active-bg);
  color: var(--chip-active-text);
}

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
  box-shadow: var(--shadow);
  color: var(--text);
  transition: transform 0.12s ease, box-shadow 0.12s ease;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 14px rgba(20, 20, 30, 0.1);
}

/* Stretched-link pattern: the whole card links to the paper, but the
   GitHub link (rendered above it, z-index 2) still gets its own clicks. */
.card-overlay-link {
  position: absolute;
  inset: 0;
  z-index: 1;
  border-radius: inherit;
}

.card-title {
  font-size: 0.95rem;
  font-weight: 600;
  margin: 0 0 4px;
  line-height: 1.35;
}

.card-abbr {
  color: var(--accent);
}

.card-authors {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin: 0 0 10px;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.card-tags .chip {
  cursor: default;
  font-size: 0.72rem;
  padding: 3px 8px;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: auto;
  padding-top: 10px;
}

.card-github {
  position: relative;
  z-index: 2;
  color: var(--accent);
  font-weight: 500;
  text-decoration: none;
}

.card-github:hover {
  text-decoration: underline;
}

.empty-state {
  color: var(--text-muted);
  font-size: 0.9rem;
  padding: 40px 0;
  text-align: center;
  grid-column: 1 / -1;
}

@media (max-width: 800px) {
  .app {
    grid-template-columns: 1fr;
  }
  .sidebar {
    position: static;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
}