:root {
  --bg: #1a1a2e;
  --bg-card: #16213e;
  --bg-input: #0f3460;
  --accent: #e94560;
  --accent-dim: #c73650;
  --text: #eee;
  --text-dim: #999;
  --text-label: #bbb;
  --green: #4ecca3;
  --yellow: #f0c040;
  --red: #e94560;
  --border: #2a2a4a;
  --radius: 8px;
  --svg-grid: #1a1a2e;
  --svg-frame: #555;
  --svg-dim-subtle: #555;
  --svg-text-subtle: #666;
  --svg-ground: #2a2a4a;
  --svg-bb-label: #999;
}

:root.light {
  --bg: #f0f2f5;
  --bg-card: #fff;
  --bg-input: #f7f8fa;
  --text: #1a1a2e;
  --text-dim: #666;
  --text-label: #555;
  --border: #d0d5dd;
  --svg-grid: #e8eaed;
  --svg-frame: #888;
  --svg-dim-subtle: #999;
  --svg-text-subtle: #888;
  --svg-ground: #ccc;
  --svg-bb-label: #777;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
  transition: background-color 0.3s, color 0.3s;
}

header {
  background: var(--bg-card);
  border-bottom: 2px solid var(--accent);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

header h1 {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

header h1 span { color: var(--accent); }

.mode-toggle {
  display: flex;
  background: var(--bg);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
}

.mode-toggle button {
  padding: 8px 16px;
  border: none;
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 500;
  transition: all 0.2s;
  white-space: nowrap;
}

.mode-toggle button.active {
  background: var(--accent);
  color: #fff;
}

.mode-toggle button:hover:not(.active) {
  color: var(--text);
  background: var(--border);
}

main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 20px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.card h2 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-size: 0.85rem;
}

.input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.input-group label {
  font-size: 0.75rem;
  color: var(--text-label);
  font-weight: 500;
}

.input-group input {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 8px 10px;
  color: var(--text);
  font-size: 0.9rem;
  width: 100%;
  font-family: inherit;
  transition: border-color 0.2s;
}

.input-group input:focus {
  outline: none;
  border-color: var(--accent);
}

.input-group input:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.input-group .unit {
  font-size: 0.7rem;
  color: var(--text-dim);
}

.results-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.result-item {
  background: var(--bg);
  border-radius: 6px;
  padding: 12px;
  text-align: center;
}

.result-item .result-label {
  font-size: 0.7rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 4px;
}

.info-tip {
  cursor: help;
  font-size: 0.85rem;
  color: var(--accent);
  vertical-align: middle;
  position: relative;
}

.inline-result {
  font-size: 0.72rem;
  color: var(--accent);
  margin-top: 2px;
  cursor: help;
  position: relative;
}

.tip-text {
  display: none;
  position: absolute;
  bottom: 100%;
  left: 0;
  background: var(--bg-input);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 10px;
  font-size: 0.7rem;
  line-height: 1.4;
  width: 260px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.3);
  z-index: 100;
  margin-bottom: 4px;
  text-transform: none;
  letter-spacing: normal;
  font-weight: 400;
}

.inline-result:hover .tip-text,
.label-tip:hover .tip-text,
.inline-result.tip-active .tip-text,
.label-tip.tip-active .tip-text {
  display: block;
}

.label-tip {
  cursor: help;
  color: var(--accent);
  position: relative;
  font-style: normal;
}

.result-item .result-value {
  font-size: 1.4rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.result-item .result-unit {
  font-size: 0.7rem;
  color: var(--text-dim);
}

.result-item.highlight {
  border: 1px solid var(--accent);
}

.result-good .result-value { color: var(--green); }
.result-warn .result-value { color: var(--yellow); }
.result-bad .result-value { color: var(--red); }

.diagram-container {
  grid-column: 1 / -1;
}

.diagram-container svg {
  width: 100%;
  height: auto;
  display: block;
}

.constraint-section {
  margin-bottom: 16px;
  padding: 12px;
  background: var(--bg);
  border-radius: 6px;
}

.constraint-section label {
  font-size: 0.8rem;
  color: var(--text-label);
  display: block;
  margin-bottom: 8px;
}

.constraint-section select {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 6px 10px;
  color: var(--text);
  font-size: 0.85rem;
  width: 100%;
  font-family: inherit;
}

.constraint-section select:focus {
  outline: none;
  border-color: var(--accent);
}

.reverse-results {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 12px;
}

.reverse-result {
  background: var(--bg);
  border: 1px solid var(--green);
  border-radius: 6px;
  padding: 12px;
  text-align: center;
}

.reverse-result .rr-label {
  font-size: 0.7rem;
  color: var(--text-dim);
  text-transform: uppercase;
  margin-bottom: 4px;
}

.reverse-result .rr-value {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--green);
  font-variant-numeric: tabular-nums;
}

.reverse-result .rr-unit {
  font-size: 0.7rem;
  color: var(--text-dim);
}

.reverse-result.rr-warn {
  border-color: var(--yellow);
}

.reverse-result.rr-warn .rr-value {
  color: var(--yellow);
}

.reverse-result.rr-bad {
  border-color: var(--red);
}

.reverse-result.rr-bad .rr-value {
  color: var(--red);
}

.note {
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-top: 8px;
  font-style: italic;
}

.theme-toggle {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 6px 12px;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 0.85rem;
  font-family: inherit;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 6px;
}

.theme-toggle:hover {
  color: var(--text);
  border-color: var(--accent);
}

.theme-toggle .theme-icon { font-size: 1rem; }

.header-controls {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

footer {
  max-width: 1400px;
  margin: 0 auto;
  padding: 20px 20px 32px;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
}

.preset-trigger {
  margin-top: 12px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.preset-trigger-btn {
  background: var(--accent);
  border: none;
  border-radius: var(--radius);
  padding: 8px 20px;
  color: #fff;
  cursor: pointer;
  font-size: 0.85rem;
  font-family: inherit;
  font-weight: 600;
  transition: all 0.2s;
}

.preset-trigger-btn:hover {
  background: var(--accent-dim);
}

.frame-action-btn {
  width: 200px;
  text-align: center;
}

.compare-btn {
  background: var(--green);
}

.compare-btn:hover {
  background: #3db888;
}

.preset-active-label {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-style: italic;
}

.info-btn {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 6px 12px;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 0.85rem;
  font-family: inherit;
  transition: all 0.2s;
}

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

.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 1000;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.modal-overlay.open {
  display: flex;
}

.modal {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  max-width: 640px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  padding: 28px;
  position: relative;
}

.modal h2 {
  color: var(--accent);
  font-size: 1.1rem;
  margin-bottom: 16px;
}

.modal h3 {
  color: var(--text);
  font-size: 0.9rem;
  margin-top: 16px;
  margin-bottom: 6px;
}

.modal p, .modal li {
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.6;
}

.modal ul {
  padding-left: 20px;
  margin-bottom: 8px;
}

.modal li { margin-bottom: 4px; }

.modal-close {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 1.4rem;
  cursor: pointer;
  line-height: 1;
}

.modal-close:hover { color: var(--accent); }

/* Preset Modal */
.preset-modal {
  max-width: 700px;
  max-height: 85vh;
}

.preset-search {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 14px;
  color: var(--text);
  font-size: 0.9rem;
  font-family: inherit;
  margin-bottom: 16px;
}

.preset-search:focus {
  outline: none;
  border-color: var(--accent);
}

.preset-search::placeholder {
  color: var(--text-dim);
}

.preset-brand {
  margin-bottom: 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.preset-brand-header {
  background: var(--bg);
  padding: 10px 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 600;
  font-size: 0.95rem;
  user-select: none;
  transition: background 0.2s;
}

.preset-brand-header:hover {
  background: var(--border);
}

.preset-brand-header .chevron {
  transition: transform 0.2s;
  font-size: 0.8rem;
  color: var(--text-dim);
}

.preset-brand.open .chevron {
  transform: rotate(90deg);
}

.preset-brand-body {
  display: none;
  padding: 8px 14px 14px;
}

.preset-brand.open .preset-brand-body {
  display: block;
}

.preset-model {
  margin-bottom: 10px;
}

.preset-model:last-child {
  margin-bottom: 0;
}

.preset-model-name {
  font-size: 0.8rem;
  color: var(--text-label);
  font-weight: 500;
  margin-bottom: 6px;
}

.preset-model-name .model-year {
  color: var(--text-dim);
  font-weight: 400;
}

.preset-sizes {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.preset-size-btn {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 5px 12px;
  color: var(--text);
  cursor: pointer;
  font-size: 0.78rem;
  font-family: inherit;
  font-weight: 600;
  transition: all 0.2s;
}

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

.preset-size-btn.no-data {
  opacity: 0.35;
  cursor: not-allowed;
}

.preset-size-btn.no-data:hover {
  border-color: var(--border);
  color: var(--text);
}

/* Compare Frames */
.compare-selectors {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 20px;
}

.compare-frame-selector {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 16px;
  text-align: center;
}

.compare-frame-selector h3 {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.compare-frame-selector.frame-a h3 { color: var(--accent); }
.compare-frame-selector.frame-b h3 { color: var(--green); }

.compare-frame-label {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 12px;
  font-style: italic;
  min-height: 1.3em;
}

.compare-diagram {
  margin-bottom: 20px;
}

.compare-diagram svg {
  width: 100%;
  height: auto;
  display: block;
}

.compare-legend {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-top: 8px;
  font-size: 0.8rem;
  color: var(--text-dim);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.legend-swatch {
  display: inline-block;
  width: 14px;
  height: 3px;
  border-radius: 2px;
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}

.compare-table th,
.compare-table td {
  padding: 10px 14px;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.compare-table th {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-dim);
  font-weight: 600;
}

.compare-table td.compare-metric {
  text-align: left;
  font-weight: 500;
  color: var(--text-label);
}

.compare-table td.compare-val-a {
  color: var(--accent);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.compare-table td.compare-val-b {
  color: var(--green);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.compare-table td.compare-diff {
  color: var(--text);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* Hoods / Handlebars Toggle */
.measure-toggle-wrapper {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-left: 12px;
  vertical-align: middle;
  color: #fff;
  font-size: 0.75rem;
  font-weight: 500;
}

.measure-toggle-wrapper .separator {
  color: var(--text-dim);
  font-weight: 300;
}

.measure-toggle {
  display: inline-flex;
  background: var(--bg);
  border-radius: 4px;
  overflow: hidden;
  border: 1px solid var(--border);
}

.measure-toggle button {
  padding: 3px 10px;
  border: none;
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 0.75rem;
  font-family: inherit;
  font-weight: 500;
  transition: all 0.2s;
  white-space: nowrap;
}

.measure-toggle button.active {
  background: var(--accent);
  color: #fff;
}

.measure-toggle button:hover:not(.active) {
  color: var(--text);
  background: var(--border);
}

.hidden { display: none !important; }

@media (max-width: 768px) {
  main {
    grid-template-columns: 1fr;
    padding: 12px;
  }
  .input-grid {
    grid-template-columns: 1fr;
  }
  header {
    padding: 12px 16px;
  }
  header h1 {
    font-size: 1.1rem;
  }
  .mode-toggle button {
    padding: 6px 12px;
    font-size: 0.8rem;
  }
  .diagram-container svg text {
    font-size: 16px !important;
  }
  .tip-text {
    left: 50% !important;
    transform: translateX(-50%);
  }
  .compare-selectors {
    grid-template-columns: 1fr;
  }
}