/* Polyhedron Corpus Interactive Visual Gallery Stylesheet */

/* Default / Theme 1: Swiss Precision / Bauhaus Studio (Zero-Chroma Carbon & Archival Amber/Ochre) */
:root {
  color-scheme: dark;
}

:root,
body[data-theme="bauhaus"] {
  --bg-primary: #09090b;
  --bg-secondary: #121215;
  --bg-card: #18181c;
  --bg-card-hover: #24242a;
  --border-color: #282830;
  --border-focus: #f59e0b;
  --text-primary: #fafafa;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --accent-primary: #f59e0b;
  --accent-cyan: #f59e0b;
  --accent-teal: #fbbf24;
  --accent-indigo: #d97706;
  --accent-purple: #a855f7;
  --accent-emerald: #10b981;
  --accent-rose: #f43f5e;
  --canvas-bg: radial-gradient(circle at center, #272730 0%, #09090b 100%);
  --card-top-highlight: linear-gradient(180deg, rgba(255, 255, 255, 0.05) 0%, rgba(255, 255, 255, 0) 100%);
  --badge-bg: rgba(245, 158, 11, 0.12);
  --badge-border: rgba(245, 158, 11, 0.28);
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.5);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.6), 0 2px 4px -2px rgba(0, 0, 0, 0.6);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.7), 0 4px 6px -4px rgba(0, 0, 0, 0.7);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
}

/* Theme 2: Archival Vitrine (Da Vinci "De Divina Proportione" — Warm Obsidian & Burnished Gold) */
body[data-theme="vitrine"] {
  --bg-primary: #0f0e0d;
  --bg-secondary: #171513;
  --bg-card: #1a1714;
  --bg-card-hover: #24201b;
  --border-color: #2b251f;
  --border-focus: #d4af37;
  --text-primary: #fdfbf7;
  --text-secondary: #a89f91;
  --text-muted: #736b60;
  --accent-primary: #d4af37;
  --accent-cyan: #d4af37;
  --accent-teal: #e6ca65;
  --accent-indigo: #c5a059;
  --accent-purple: #c084fc;
  --accent-emerald: #10b981;
  --accent-rose: #e06c75;
  --canvas-bg: radial-gradient(circle at center, #221e1a 0%, #0d0c0b 100%);
  --card-top-highlight: linear-gradient(180deg, rgba(212, 175, 55, 0.05) 0%, rgba(212, 175, 55, 0) 100%);
  --badge-bg: rgba(212, 175, 55, 0.12);
  --badge-border: rgba(212, 175, 55, 0.28);
}

/* Theme 3: Nordic Mineral & Volcanic Basalt (Volcanic Basalt & Celestial Jade/Sage) */
body[data-theme="nordic"] {
  --bg-primary: #080a0c;
  --bg-secondary: #0e1217;
  --bg-card: #131920;
  --bg-card-hover: #1b2430;
  --border-color: #222d3a;
  --border-focus: #34d399;
  --text-primary: #f0fdf4;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-primary: #34d399;
  --accent-cyan: #34d399;
  --accent-teal: #2dd4bf;
  --accent-indigo: #10b981;
  --accent-purple: #818cf8;
  --accent-emerald: #34d399;
  --accent-rose: #fb7185;
  --canvas-bg: radial-gradient(circle at center, #1b2636 0%, #080a0c 100%);
  --card-top-highlight: linear-gradient(180deg, rgba(52, 211, 153, 0.06) 0%, rgba(52, 211, 153, 0) 100%);
  --badge-bg: rgba(52, 211, 153, 0.12);
  --badge-border: rgba(52, 211, 153, 0.28);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  overflow-x: hidden;
  max-width: 100vw;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header & Navigation */
header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 1.25rem 2rem;
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(12px);
}

.header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.4);
  transition: all 0.2s ease;
}

.brand-icon svg {
  width: 22px;
  height: 22px;
}

.brand h1 {
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.brand-badge {
  background: var(--badge-bg);
  color: var(--accent-primary);
  border: 1px solid var(--badge-border);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.55rem;
  border-radius: 9999px;
  font-family: ui-monospace, SFMono-Regular, "Roboto Mono", Menlo, Monaco, Consolas, monospace;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.search-bar {
  position: relative;
  width: 280px;
}

.search-bar input {
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.5rem 0.85rem 0.5rem 2.25rem;
  color: var(--text-primary);
  font-size: 0.875rem;
  outline: none;
  transition: all 0.2s ease;
}

.search-bar input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
}

.search-icon {
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  width: 16px;
  height: 16px;
}

/* Category Filter Bar */
.filter-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 1rem;
  flex-wrap: wrap;
  gap: 0.75rem;
  max-width: 100%;
}

.category-pills {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  overflow-x: auto;
  max-width: 100%;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 0.25rem;
}

.pill-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.35rem 0.75rem;
  border-radius: 9999px;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.15s ease;
}

.pill-btn:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border-color: var(--text-muted);
}

.pill-btn.active {
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-cyan);
  border-color: var(--accent-cyan);
  font-weight: 600;
}

.filter-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.select-control {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.8125rem;
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius-sm);
  outline: none;
  cursor: pointer;
}

/* Main Layout Grid */
.main-container {
  display: grid;
  grid-template-columns: 1fr 460px;
  gap: 1.5rem;
  padding: 1.5rem 2rem;
  flex: 1;
  max-width: 1800px;
  margin: 0 auto;
  width: 100%;
  align-items: start;
}

@media (max-width: 1200px) {
  .main-container {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  header {
    padding: 0.75rem 1rem;
  }
  .main-container {
    padding: 1rem 0.75rem;
  }
  .search-bar {
    width: 100%;
  }
  .filter-bar {
    flex-direction: column;
    align-items: stretch;
  }
  .category-pills {
    width: 100%;
  }
  .filter-controls {
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 0.5rem;
  }
  .select-control {
    width: 100%;
  }
  .comparison-section {
    flex-direction: column;
    text-align: center;
  }
}

/* Left: Polyhedra Grid */
.gallery-section {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* Subset Description Banner */
.category-banner {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--accent-primary);
  border-radius: var(--radius-md);
  padding: 1.15rem 1.35rem;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
}

.category-banner-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.45rem;
}

.category-banner-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.category-banner-badge {
  background: var(--badge-bg);
  color: var(--accent-primary);
  border: 1px solid var(--badge-border);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 9999px;
  white-space: nowrap;
  font-family: ui-monospace, SFMono-Regular, "Roboto Mono", Menlo, Monaco, Consolas, monospace;
}

.category-banner-desc {
  font-size: 0.875rem;
  line-height: 1.55;
  color: var(--text-secondary);
}

.gallery-stats {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.polyhedra-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
}

.poly-card {
  background: var(--bg-card);
  background-image: var(--card-top-highlight);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.875rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.poly-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.12), transparent);
  pointer-events: none;
}

.poly-card:hover {
  transform: translateY(-2px);
  background: var(--bg-card-hover);
  border-color: var(--accent-primary);
  box-shadow: 0 8px 24px -4px rgba(0, 0, 0, 0.6), 0 0 0 1px var(--accent-primary);
}

.poly-card.selected {
  border-color: var(--accent-primary);
  background: var(--bg-card-hover);
  box-shadow: 0 0 0 2px var(--accent-primary);
}

.card-img-wrapper {
  width: 130px;
  height: 130px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 0.75rem;
  position: relative;
}

.card-img-wrapper img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.4));
  transition: transform 0.2s ease, filter 0.3s ease;
}

/* Shape Shading Palette Transforms for Gallery Cards & Inspector Preview */
body[data-palette="cool"] .card-img-wrapper img {
  filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.4));
}
body[data-palette="cool"] .svg-preview-box img {
  filter: none;
}

body[data-palette="warm"] .card-img-wrapper img {
  filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.4)) hue-rotate(165deg) saturate(1.4) contrast(1.02);
}
body[data-palette="warm"] .svg-preview-box img {
  filter: hue-rotate(165deg) saturate(1.4) contrast(1.02);
}

body[data-palette="slate"] .card-img-wrapper img {
  filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.4)) saturate(0.2) brightness(0.95) contrast(1.05);
}
body[data-palette="slate"] .svg-preview-box img {
  filter: saturate(0.2) brightness(0.95) contrast(1.05);
}

.poly-card:hover .card-img-wrapper img {
  transform: scale(1.05);
}

.card-info {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  text-align: center;
  flex: 1;
  justify-content: space-between;
}

.card-category {
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-primary);
  font-weight: 600;
}

.card-name {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: normal;
  overflow: visible;
  text-overflow: unset;
  word-break: normal;
  overflow-wrap: break-word;
  line-height: 1.35;
  width: 100%;
  min-height: 2.7em;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-metrics {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  margin-top: 0.4rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: ui-monospace, SFMono-Regular, "Roboto Mono", Menlo, Monaco, Consolas, monospace;
  font-variant-numeric: tabular-nums;
}

.card-metrics span {
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
}

.card-metrics b {
  color: var(--text-secondary);
  font-weight: 600;
}

/* Infinite Scroll Sentinel & Status */
.scroll-sentinel {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2.5rem 1rem;
  margin-top: 1rem;
}

.scroll-status {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.5rem 1.25rem;
  border-radius: 9999px;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
}

.scroll-status.all-loaded {
  background: var(--badge-bg);
  border-color: var(--badge-border);
  color: var(--accent-primary);
}


/* Right: 3D Inspector Panel (Sticky) */
.inspector-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1rem 1.15rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  position: sticky;
  top: 7.5rem;
  align-self: start;
  height: fit-content;
  box-shadow: var(--shadow-lg);
}

.inspector-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.5rem;
}

.inspector-title-group h2 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.inspector-title-group p {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.15rem;
  font-family: ui-monospace, SFMono-Regular, "Roboto Mono", Menlo, Monaco, Consolas, monospace;
}

.badge-tag {
  background: var(--badge-bg);
  color: var(--accent-primary);
  border: 1px solid var(--badge-border);
  font-size: 0.6875rem;
  font-weight: 600;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  font-family: ui-monospace, SFMono-Regular, "Roboto Mono", Menlo, Monaco, Consolas, monospace;
}

/* 3D WebGL Canvas Area */
.canvas-wrapper {
  width: 100%;
  height: 200px;
  min-height: 200px;
  flex-shrink: 0;
  background: var(--canvas-bg);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  position: relative;
  overflow: hidden;
  transition: background 0.3s ease;
}

#viewport-canvas {
  width: 100%;
  height: 100%;
  display: block;
  outline: none;
}

.viewport-overlay {
  position: absolute;
  bottom: 0.6rem;
  right: 0.6rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.overlay-btn {
  background: rgba(15, 23, 42, 0.75);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--text-primary);
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 0.75rem;
  transition: all 0.15s ease;
}

.overlay-btn:hover {
  background: var(--badge-bg);
  border-color: var(--accent-primary);
  color: var(--accent-primary);
}

.overlay-btn.active {
  background: var(--accent-primary);
  color: #0b0f19;
  border-color: var(--accent-primary);
}

/* Side-by-Side SVG Preview Card */
.comparison-section {
  display: flex;
  gap: 0.65rem;
  background: rgba(11, 15, 25, 0.5);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.45rem 0.65rem;
  align-items: center;
}

.svg-preview-box {
  width: 48px;
  height: 48px;
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-color);
  flex-shrink: 0;
}

.svg-preview-box img {
  max-width: 90%;
  max-height: 90%;
}

.comparison-details {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  font-size: 0.72rem;
}

.comparison-details b {
  color: var(--text-primary);
  font-size: 0.8125rem;
}

.comparison-details span {
  color: var(--text-muted);
}

/* Metric Invariants Cards */
.metrics-table {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.35rem;
}

.metric-cell {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.35rem 0.45rem;
  text-align: center;
}

.metric-cell .label {
  font-size: 0.625rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.metric-cell .value {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 0.1rem;
  font-family: ui-monospace, SFMono-Regular, "Roboto Mono", Menlo, Monaco, Consolas, monospace;
  font-variant-numeric: tabular-nums;
}

/* Verification Badges */
.verification-status-box {
  background: rgba(16, 185, 129, 0.08);
  border: 1px solid rgba(16, 185, 129, 0.25);
  border-radius: var(--radius-sm);
  padding: 0.45rem 0.6rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.verification-status-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-emerald);
}

.gates-pills {
  display: flex;
  gap: 0.3rem;
  flex-wrap: wrap;
}

.gate-pill {
  font-size: 0.625rem;
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-weight: 600;
  font-family: ui-monospace, SFMono-Regular, "Roboto Mono", Menlo, Monaco, Consolas, monospace;
}

/* Inspector Downloads (OBJ Default, STL Last) */
.inspector-downloads {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding-top: 0.45rem;
  border-top: 1px solid var(--border-color);
}

.downloads-heading {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.downloads-heading-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.downloads-title {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.downloads-badge {
  font-size: 0.625rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 0.15rem 0.4rem;
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--accent-primary);
}

.downloads-subhead {
  font-size: 0.6875rem;
  color: var(--text-muted);
  line-height: 1.3;
}

.download-category {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  min-width: 0;
}

.category-header-line {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.4rem;
  min-height: 1.1rem;
}

.category-label {
  font-size: 0.6875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  white-space: nowrap;
}

.category-hint {
  font-size: 0.625rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.actions-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.4rem;
}

.actions-group-secondary {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.4rem;
}

.actions-group-stl {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.35rem;
}

.download-subcategories-header {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.35rem;
  align-items: center;
  min-height: 1.1rem;
}

.subcat-header-col.design-col {
  grid-column: span 2;
  display: flex;
  align-items: center;
}

.subcat-header-col.data-col {
  grid-column: span 1;
  display: flex;
  align-items: center;
}

.actions-group-secondary-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.35rem;
}

.btn-action {
  background-color: var(--accent-primary) !important;
  border: 1px solid var(--accent-primary) !important;
  color: #000000 !important;
  -webkit-text-fill-color: #000000 !important;
  min-height: 2.15rem;
  padding: 0.45rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.15s ease;
  white-space: nowrap;
  box-sizing: border-box;
}

.btn-action:hover {
  filter: brightness(1.12);
  color: #000000 !important;
  -webkit-text-fill-color: #000000 !important;
}

.btn-primary {
  background-color: var(--accent-primary) !important;
  border: 1px solid var(--accent-primary) !important;
  color: #000000 !important;
  -webkit-text-fill-color: #000000 !important;
  font-weight: 700;
}

.btn-primary:hover {
  filter: brightness(1.12);
  color: #000000 !important;
  -webkit-text-fill-color: #000000 !important;
}

.btn-sm {
  min-height: 1.7rem;
  padding: 0.25rem 0.25rem;
  font-size: 0.6875rem;
  font-weight: 600;
}

.btn-stl {
  background-color: var(--accent-primary) !important;
  border: 1px solid var(--accent-primary) !important;
  color: #000000 !important;
  -webkit-text-fill-color: #000000 !important;
}

.btn-stl:hover {
  filter: brightness(1.12);
  color: #000000 !important;
  -webkit-text-fill-color: #000000 !important;
}

/* Explicit high-contrast icon styling inside action buttons */
.btn-action svg {
  color: #000000 !important;
  stroke: #000000 !important;
  flex-shrink: 0;
}

.btn-action svg[fill="currentColor"] {
  fill: #000000 !important;
  stroke: none !important;
}

.btn-action svg[fill="currentColor"] path {
  fill: #000000 !important;
}

.btn-action svg[stroke="currentColor"] {
  stroke: #000000 !important;
  fill: none !important;
}

.btn-action svg[stroke="currentColor"] polygon,
.btn-action svg[stroke="currentColor"] polyline,
.btn-action svg[stroke="currentColor"] path,
.btn-action svg[stroke="currentColor"] circle {
  stroke: #000000 !important;
}

.nav-action-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.8125rem;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.nav-action-btn:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
}

/* How It Works Modal Dialog */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  max-width: 900px;
  width: 100%;
  max-height: 85vh;
  display: flex;
  flex-direction: column;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.75);
  overflow: hidden;
}

.modal-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
}

.modal-title-group h2 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.modal-title-group p {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

.modal-close-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.75rem;
  line-height: 1;
  cursor: pointer;
  padding: 0.25rem;
  border-radius: var(--radius-sm);
  transition: color 0.15s ease;
}

.modal-close-btn:hover {
  color: var(--text-primary);
}

.modal-tabs {
  display: flex;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  overflow-x: auto;
}

.modal-tab-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.15s ease;
}

.modal-tab-btn:hover {
  color: var(--text-primary);
}

.modal-tab-btn.active {
  background: var(--bg-card);
  border-color: var(--border-color);
  color: var(--accent-primary);
}

.modal-body {
  padding: 1.5rem;
  overflow-y: auto;
  flex: 1;
}

.tab-pane {
  display: none;
}

.tab-pane.active {
  display: block;
}

.tab-pane h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.tab-pane p {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.modal-list {
  padding-left: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  font-size: 0.875rem;
  line-height: 1.55;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.modal-list b {
  color: var(--text-primary);
}

.formula-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1rem;
  font-family: ui-monospace, SFMono-Regular, "Roboto Mono", Menlo, Monaco, Consolas, monospace;
  color: var(--accent-primary);
  font-size: 0.875rem;
}

.modal-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8125rem;
  margin-top: 0.75rem;
  margin-bottom: 1rem;
}

.modal-table th,
.modal-table td {
  padding: 0.65rem 0.85rem;
  text-align: left;
  border: 1px solid var(--border-color);
}

.modal-table th {
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-weight: 600;
}

.modal-table td {
  color: var(--text-secondary);
}

.modal-table td b {
  color: var(--text-primary);
}