:root {
  --bg: #eaf1fb;                /* soft sky-blue page */
  --surface: #ffffff;           /* cards / inputs pop as white */
  --ink: #1e293b;               /* slate-800 */
  --ink-soft: #475569;          /* slate-600 */
  --ink-faint: #94a3b8;         /* slate-400 */
  --line: #cfdcec;              /* cool blue-gray border */
  --accent: #1d4ed8;            /* blue-700 — UI accent */
  --accent-soft: #dbeafe;       /* blue-100 — focus rings, code bg */
  --accent-bar: hsl(210, 60%, 48%);
  --user: #ea580c;              /* warm coral, pops against the cool palette */
  --user-soft: #ffedd5;         /* peach */
  --track-bg: rgba(29, 78, 216, 0.08);
  --radius: 8px;
  --max-w: 960px;
  --max-w-text: 720px;
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.04), 0 4px 12px rgba(15, 23, 42, 0.05);
  --footer-h: 44px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
}

code {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.875em;
  background: var(--accent-soft);
  padding: 1px 6px;
  border-radius: 4px;
}

/* ----- Header ----- */

.site-header {
  padding: 0;
  flex-shrink: 0;
}

.site-header h1 {
  margin: 0;
  font-size: 1.5rem;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.tagline {
  margin: 2px 0 0;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

/* ----- Scroll stage / main view ----- */

.scroll-stage {
  position: relative;
  /* dynamic height set by JS based on bar count */
}

.main-view {
  position: sticky;
  top: 0;
  height: 100vh;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 16px 24px calc(var(--footer-h) + 16px);
  display: flex;
  flex-direction: column;
  gap: 14px;
  background: var(--bg);
  z-index: 2;
}

/* ----- Inputs ----- */

.inputs {
  display: flex;
  flex-direction: column;
  gap: 10px;
  width: 100%;
  max-width: var(--max-w-text);
  align-self: center;
}

.output {
  width: 100%;
  max-width: var(--max-w-text);
  align-self: center;
}

.tabs {
  display: flex;
  gap: 4px;
  border-bottom: 1px solid var(--line);
}

.tab {
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  padding: 8px 14px;
  color: var(--ink-soft);
  font-weight: 500;
  margin-bottom: -1px;
  transition: color 120ms ease, border-color 120ms ease;
}

.tab:hover {
  color: var(--ink);
}

.tab.is-active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab-panel.is-hidden {
  display: none;
}

#paste-input {
  width: 100%;
  min-height: 96px;
  max-height: 30vh;
  padding: 12px 14px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 0.95rem;
  line-height: 1.5;
  color: var(--ink);
  resize: vertical;
  outline: none;
  transition: border-color 120ms ease, box-shadow 120ms ease;
}

#paste-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

#count-input {
  width: 100%;
  padding: 12px 14px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;
  font-size: 1rem;
  color: var(--ink);
  outline: none;
  transition: border-color 120ms ease, box-shadow 120ms ease;
}

#count-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.count-hint {
  margin: 6px 0 0;
  color: var(--ink-faint);
  font-size: 0.85rem;
}

.stats {
  margin: 4px 0 0;
  color: var(--ink-soft);
  font-size: 0.9rem;
  font-variant-numeric: tabular-nums;
  min-height: 1.4em;
}

.stats strong {
  color: var(--ink);
  font-weight: 600;
}

.stats-loading {
  color: var(--ink-faint);
  font-style: italic;
}

/* ----- Comparison output ----- */

.output {
  min-height: 2.6em;
}

.comparison {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--ink);
}

.comparison-empty {
  color: var(--ink-faint);
}

.comparison-num {
  color: var(--accent);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  margin-right: 2px;
}

/* ----- Reference picker (chip + popover) ----- */

.ref-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px 3px 12px;
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid transparent;
  border-radius: 999px;
  font: inherit;
  font-size: 0.95em;
  font-weight: 600;
  line-height: 1.4;
  cursor: pointer;
  vertical-align: baseline;
  white-space: nowrap;
  transition: background-color 160ms ease, color 160ms ease,
              border-color 160ms ease, box-shadow 160ms ease;
}

.ref-chip:hover {
  background: #c7dafe;
}

.ref-chip:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px rgba(29, 78, 216, 0.25);
}

.ref-chip[aria-expanded="true"] {
  background: var(--accent);
  color: white;
}

.ref-chip-arrow {
  display: inline-block;
  font-size: 0.7em;
  line-height: 1;
  transition: transform 200ms cubic-bezier(0.22, 1, 0.36, 1);
  opacity: 0.85;
}

.ref-chip[aria-expanded="true"] .ref-chip-arrow {
  transform: rotate(180deg);
}

.ref-popover {
  position: fixed;
  top: 0;
  left: 0;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow:
    0 16px 40px rgba(15, 23, 42, 0.14),
    0 4px 12px rgba(15, 23, 42, 0.08);
  padding: 6px;
  z-index: 100;
  min-width: 300px;
  max-width: min(380px, calc(100vw - 24px));
  max-height: min(360px, calc(100vh - 80px));
  overflow-y: auto;
  opacity: 0;
  transform: translateY(-6px) scale(0.98);
  transform-origin: top left;
  visibility: hidden;
  pointer-events: none;
  transition:
    opacity 160ms ease,
    transform 180ms cubic-bezier(0.22, 1, 0.36, 1),
    visibility 0s linear 180ms;
}

.ref-popover.is-open {
  opacity: 1;
  transform: translateY(0) scale(1);
  visibility: visible;
  pointer-events: auto;
  transition:
    opacity 160ms ease,
    transform 180ms cubic-bezier(0.22, 1, 0.36, 1),
    visibility 0s;
}

.ref-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.ref-item {
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: 12px;
  align-items: center;
  padding: 8px 10px;
  border-radius: 7px;
  cursor: pointer;
  font-size: 0.88rem;
  color: var(--ink);
  transition: background-color 100ms ease, color 100ms ease;
}

.ref-item:hover {
  background: rgba(29, 78, 216, 0.07);
}

.ref-item.is-selected {
  background: var(--accent);
  color: white;
}

.ref-item-label {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.ref-item-count {
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
  font-size: 0.82em;
}

.ref-item-ratio {
  color: var(--ink-soft);
  font-variant-numeric: tabular-nums;
  font-size: 0.78em;
  font-weight: 600;
  background: rgba(29, 78, 216, 0.08);
  padding: 2px 7px;
  border-radius: 999px;
  white-space: nowrap;
  min-width: 44px;
  text-align: center;
}

.ref-item.is-selected .ref-item-count,
.ref-item.is-selected .ref-item-ratio {
  color: white;
  background: rgba(255, 255, 255, 0.18);
}

/* ----- Chart ----- */

.chart-section {
  margin-top: 4px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-height: 0;
  overflow: hidden;
}

.bars {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.bar-row {
  order: var(--order, 0);
  display: grid;
  grid-template-columns: minmax(0, 42%) 1fr;
  align-items: center;
  gap: 14px;
  max-height: 50px;
  opacity: 1;
  overflow: hidden;
  padding-top: 7px;
  transition:
    max-height 480ms cubic-bezier(0.22, 1, 0.36, 1),
    opacity 320ms ease,
    padding-top 480ms cubic-bezier(0.22, 1, 0.36, 1);
}

.bar-row.is-inactive {
  max-height: 0;
  opacity: 0;
  padding-top: 0;
  pointer-events: none;
}

.bar-label {
  font-size: 0.84rem;
  font-weight: 500;
  color: var(--ink);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin: 0;
}

.bar-track {
  position: relative;
  height: 26px;
  background: var(--track-bg);
  border-radius: 5px;
}

.bar-fill {
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 0%;
  background: var(--bar-color, var(--accent-bar));
  border-radius: 5px;
  transition: width 540ms cubic-bezier(0.22, 1, 0.36, 1),
              background-color 240ms ease;
}

.bar-count {
  position: absolute;
  top: 50%;
  left: 0;
  transform: translate3d(0, -50%, 0);
  font-size: 0.74rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: white;
  white-space: nowrap;
  pointer-events: none;
  text-shadow: 0 1px 1px rgba(0, 0, 0, 0.12);
  transition: transform 540ms cubic-bezier(0.22, 1, 0.36, 1),
              color 320ms ease,
              text-shadow 320ms ease;
}

.bar-row.count-outside .bar-count {
  color: var(--ink-soft);
  text-shadow: none;
}

.bar-row.is-user .bar-fill {
  background: var(--user);
}

.bar-row.is-user .bar-label {
  color: var(--user);
  font-weight: 600;
}

.bar-row.is-user .bar-track {
  background: var(--user-soft);
}

.bar-row.is-user.count-outside .bar-count {
  color: var(--user);
}

.disclaimer {
  margin: 12px 0 0;
  font-size: 0.78rem;
  color: var(--ink-faint);
  line-height: 1.5;
}

.disclaimer code {
  font-size: 0.78rem;
  background: rgba(0, 0, 0, 0.04);
}

/* ----- Scroll driver ----- */

.scroll-driver {
  /* invisible — pure scroll length to drive bar reveals */
  pointer-events: none;
  position: relative;
  z-index: 1;
}

.scroll-step {
  height: 45vh;
  width: 100%;
}

/* ----- Footer ----- */

.site-footer {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 5;
  margin: 0;
  padding: 10px 24px;
  background: var(--bg);
  border-top: 1px solid var(--line);
  color: var(--ink-faint);
  font-size: 0.85rem;
  text-align: center;
}

.site-footer p {
  margin: 0;
  max-width: var(--max-w);
  margin: 0 auto;
}

/* ----- Responsive ----- */

@media (max-width: 540px) {
  .site-header h1 { font-size: 1.35rem; }
  .tagline { font-size: 0.85rem; }
  .main-view { padding: 12px 16px calc(var(--footer-h) + 12px); gap: 12px; }
  .tab { padding: 6px 10px; font-size: 0.95rem; }
  #paste-input { min-height: 80px; }
  .comparison { font-size: 1rem; }
  .bar-meta { font-size: 0.8rem; }
  .bar-track { height: 12px; }
  .site-footer { padding: 8px 16px; }
}

@media (prefers-reduced-motion: reduce) {
  .bar-fill,
  .bar-row,
  .tab,
  #paste-input,
  #count-input {
    transition: none !important;
  }
}