/* roll-parser — shared tokens & components + playground layout.
   Warm candlelit palette; rainbow reserved for the logo/favicon, gold elsewhere.
   The reference page loads this file for tokens, fonts, logo, dice, and buttons,
   then layers reference.css on top. Keep token definitions here only. */

/*
 * * Fonts
 */

/* Self-hosted latin woff2. Cinzel, IBM Plex Sans, and JetBrains Mono are
   variable (one file spans the weight range); B612 is static (one file per
   weight). Dev path is ../public/fonts; build rewrites it to ../fonts. */
@font-face {
  font-family: 'Cinzel';
  font-style: normal;
  font-weight: 400 700;
  font-display: swap;
  src: url('../fonts/cinzel-latin.woff2') format('woff2');
}

@font-face {
  font-family: 'IBM Plex Sans';
  font-style: normal;
  font-weight: 400 700;
  font-display: swap;
  src: url('../fonts/ibm-plex-sans-latin.woff2') format('woff2');
}

@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 400 700;
  font-display: swap;
  src: url('../fonts/jetbrains-mono-latin.woff2') format('woff2');
}

@font-face {
  font-family: 'B612';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('../fonts/b612-latin-400.woff2') format('woff2');
}

@font-face {
  font-family: 'B612';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url('../fonts/b612-latin-700.woff2') format('woff2');
}

/*
 * * Tokens
 */

/* ! Foreground tokens are tuned to clear WCAG AA (4.5:1) against the tightest
   surface they land on — `--surface-strong`, not `--bg`, since the 7%/9% ink
   wash sits under the breakdown chips and mini-dice. `--die-stroke` and
   `--border` answer to the 3:1 non-text bar instead: they only paint strokes
   and component edges. The `--surface` washes carry none of that bar, so
   `--border` is measured composited over every fill it lands on, not just
   `--bg`. Re-measure before weakening any of these. */
:root {
  --bg: #16120b;
  --bg-glow: #2a2113;
  --surface: rgba(255, 240, 210, 0.05);
  --surface-strong: rgba(255, 240, 210, 0.09);
  --border: rgba(255, 230, 190, 0.45);
  --text: #f0e6d2;
  --text-muted: #b3a583;
  --text-dim: #9a8d70;
  --accent: #d9a441;
  --accent-soft: rgba(217, 164, 65, 0.4);
  --success: #a3c585;
  --failure: #d4776b;
  --die-stroke: #8a7d63;
  --gold-gradient: linear-gradient(135deg, #f0c060, #d9a441 45%, #a3622f);

  --font-head: 'Cinzel', 'Iowan Old Style', Georgia, serif;
  --font-body: 'IBM Plex Sans', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', 'Cascadia Code', Menlo, monospace;
  --font-num: 'B612', var(--font-body);

  --radius: 14px;
  --die-size: 56px;
  /* Shared height for the notation input and the square icon buttons beside it. */
  --control-h: 52px;
  --transition: 300ms cubic-bezier(0.22, 1, 0.36, 1);
  --spring: 420ms cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Light palette. The `:root` dark tokens above are the default (and the
   forced-dark case); light applies when the toggle forces it, or — in `auto`
   and before the theme script runs — when the OS prefers light. The forced
   block and the `prefers-color-scheme` block below MUST hold identical values:
   keep them in sync. */
:root[data-theme='light'] {
  --bg: #f5ecdb;
  --bg-glow: #fffaf0;
  --surface: rgba(43, 35, 23, 0.04);
  --surface-strong: rgba(43, 35, 23, 0.07);
  --border: rgba(43, 35, 23, 0.55);
  --text: #2b2317;
  --text-muted: #6b5d45;
  --text-dim: #6e6049;
  --accent: #855512;
  --accent-soft: rgba(133, 85, 18, 0.35);
  --success: #456b33;
  --failure: #9c4136;
  --die-stroke: #8a7a5c;
  --gold-gradient: linear-gradient(135deg, #976d23, #855512 45%, #593611);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme='dark']):not([data-theme='light']) {
    --bg: #f5ecdb;
    --bg-glow: #fffaf0;
    --surface: rgba(43, 35, 23, 0.04);
    --surface-strong: rgba(43, 35, 23, 0.07);
    --border: rgba(43, 35, 23, 0.55);
    --text: #2b2317;
    --text-muted: #6b5d45;
    --text-dim: #6e6049;
    --accent: #855512;
    --accent-soft: rgba(133, 85, 18, 0.35);
    --success: #456b33;
    --failure: #9c4136;
    --die-stroke: #8a7a5c;
    --gold-gradient: linear-gradient(135deg, #976d23, #855512 45%, #593611);
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

/* One gold focus ring for every link and button on both pages — components only
   need a `border-radius` for the ring to hug their shape. The notation input
   opts out: it draws a flush `box-shadow` ring instead. */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ! JetBrains Mono ligatures rewrite notation (`!=` → ≠, `>=` → ⩾), which
   changes its meaning — every notation glyph must stay literal. */
.notation-input,
.chip,
.error-echo,
.expr-note,
.grp-label,
.eq-var,
.eq-fn,
.die-badge,
.widget-notation {
  font-variant-ligatures: none;
}

html,
body {
  margin: 0;
}

body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  background-image: radial-gradient(120% 90% at 50% -10%, var(--bg-glow) 0%, var(--bg) 55%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
}

.defs {
  position: absolute;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/*
 * * Logo (shared)
 */

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  /* Rounds the shared focus ring; there is no painted border to round. */
  border-radius: 10px;
  user-select: none;
  -webkit-user-select: none;
}

.logo:hover .wordmark {
  color: var(--accent);
}

.logo-die {
  width: 46px;
  height: 46px;
}

.logo-stroke {
  fill: none;
  stroke: url(#rp-rainbow);
  stroke-width: 3;
  stroke-linejoin: round;
  stroke-linecap: round;
}

.wordmark {
  font-family: var(--font-head);
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--text);
  transition: color 150ms ease;
}

/*
 * * Dice (shared — rendered by dice.ts on both pages)
 */

.die {
  position: relative;
  width: var(--die-size);
  height: var(--die-size);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  /* `color` drives the stroke via currentColor, so state = one color swap. */
  color: var(--die-stroke);
}

@media (prefers-reduced-motion: no-preference) {
  .die {
    animation: die-pop var(--spring) both;
    animation-delay: calc(var(--i) * 32ms);
  }
}

@keyframes die-pop {
  from {
    opacity: 0;
    transform: rotate(-12deg) scale(0.4) translateY(6px);
  }
  to {
    opacity: 1;
    transform: rotate(0) scale(1) translateY(0);
  }
}

.die svg {
  width: 100%;
  height: 100%;
  overflow: visible;
}

.die-shape {
  fill: var(--surface-strong);
  stroke: currentColor;
  stroke-width: 3.5;
  stroke-linejoin: round;
  transition: stroke 150ms ease;
}

.die-facets {
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linejoin: round;
  stroke-linecap: round;
  opacity: 0.55;
}

.die-value {
  fill: var(--text);
  font-family: var(--font-num);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.die-badge {
  position: absolute;
  bottom: -2px;
  right: -2px;
  font-family: var(--font-mono);
  font-size: 0.55rem;
  font-weight: 700;
  color: var(--text-muted);
  background: var(--bg);
  border-radius: 6px;
  padding: 0 3px;
}

.die-mark {
  position: absolute;
  top: -5px;
  right: -5px;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.82rem;
  font-weight: 700;
  line-height: 1;
  border-radius: 50%;
}

/* Exploded — amber coin with a dark, readable glyph. */
.mark-explode {
  color: #1a1206;
  background: radial-gradient(circle at 35% 30%, #ffcf70, #e0952f);
  border: 1px solid rgba(0, 0, 0, 0.25);
  box-shadow: 0 0 6px rgba(224, 149, 47, 0.7);
}

.mark-reroll {
  color: var(--accent);
  background: var(--bg);
  border: 1px solid var(--border);
}

/* Colored states — one currentColor swap tints stroke + facets together. */
.die.is-success {
  color: var(--success);
}

.die.is-failure {
  color: var(--failure);
}

.die.is-fumble {
  color: var(--failure);
}

.die.is-fumble .die-shape {
  fill: color-mix(in srgb, var(--failure) 18%, transparent);
}

.die.is-critical {
  color: var(--accent);
}

.die.is-critical .die-shape {
  stroke-width: 4;
  filter: drop-shadow(0 0 7px rgba(240, 192, 96, 0.95));
}

.die.is-critical .die-value {
  fill: var(--accent);
}

.die.is-dropped {
  opacity: 0.4;
  filter: grayscale(1);
}

.die.is-dropped .die-value {
  text-decoration: line-through;
}

/* Dice past the tray's first row, hidden until the `+N` chip unfolds the tray.
   The chip is a sibling, so `is-expanded` on the tray reveals them. */
.die.is-folded {
  display: none;
}

/* Revealing restarts the pop (a `display: none` die never ran it), so the
   stagger re-bases on the fold-relative `--j` — the first die pops the instant
   the chip is clicked. The interval is tighter than the visible row's 32ms so a
   60-die tray cascades in well under a second instead of dripping. */
.is-expanded > .die.is-folded {
  display: inline-flex;
  animation-delay: calc(var(--j) * 14ms);
}

/* Squares up with a d6 so the chip reads as one more die in the row. */
.die-overflow {
  align-self: center;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: var(--die-size);
  height: var(--die-size);
  padding: 0 0.6rem;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-muted);
  background: transparent;
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  user-select: none;
  -webkit-user-select: none;
}

button.die-overflow {
  cursor: pointer;
  transition:
    color 150ms ease,
    border-color 150ms ease,
    background 150ms ease;
}

button.die-overflow:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--surface);
}

/*
 * * Icon buttons (shared)
 */

.icon-btn {
  position: relative;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--control-h);
  height: var(--control-h);
  font-size: 1.2rem;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  transition:
    background 150ms ease,
    border-color 150ms ease,
    color 150ms ease,
    transform 150ms ease;
}

.icon-btn:hover {
  background: var(--surface-strong);
  border-color: var(--accent);
  color: var(--accent);
}

/* ! Chrome matches `:active` on disabled buttons, so the press-scale needs an
   explicit `:not(:disabled)` guard — otherwise dead buttons animate on click. */
.icon-btn:not(:disabled):active {
  transform: scale(0.94);
}

.icon-btn:disabled {
  color: var(--text-dim);
  cursor: default;
  opacity: 0.55;
}

.icon-btn:disabled:hover {
  background: var(--surface);
  border-color: var(--border);
  color: var(--text-dim);
}

/* Inline Lucide icons — geometry carries fill/stroke as attributes; CSS only
   sizes them so they scale with the host button's font-size. */
.icon-svg {
  display: block;
  width: 1.4em;
  height: 1.4em;
}

.icon-btn .icon-svg {
  width: 1.25em;
  height: 1.25em;
}

/*
 * * Breakdown & degree markers (shared)
 */

.mk-dropped {
  color: var(--text-dim);
  text-decoration: line-through;
}

.mk-success {
  color: var(--success);
  font-weight: 700;
}

.mk-failure {
  color: var(--failure);
  font-weight: 700;
}

/*
 * * Structured breakdown (shared)
 */

.breakdown.equation {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.3rem 0.45rem;
  line-height: 1.4;
  word-break: normal;
}

/* Vertical padding matches the horizontal so a wrapped chip — notation on the
   first row, dice on the rest — leaves the last dice row as much room below as
   the sides get. The dice are hard-edged boxes, so any shortfall reads as a
   crop; `.grp-label` drops its leading for the same reason. */
.grp,
.brace-grp {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.3rem;
  padding: 0.45rem 0.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.grp-label {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1;
  color: var(--text-muted);
}

.grp-dice {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.25rem;
}

.grp-sub {
  font-family: var(--font-body);
  font-weight: 700;
  color: var(--text);
}

.mini-die {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 22px;
  height: 22px;
  padding: 0 3px;
  font-family: var(--font-num);
  font-size: 0.82rem;
  /* B612 regular — the small breakdown chips read cleanly at 400, leaving 700
     to the hero total and tray dice (and this loads the B612 400 face). */
  font-weight: 400;
  font-variant-numeric: tabular-nums;
  color: var(--text);
  background: var(--surface-strong);
  border: 1.5px solid var(--die-stroke);
  border-radius: 5px;
}

.mini-die.is-success {
  border-color: var(--success);
  color: var(--success);
}

.mini-die.is-failure {
  border-color: var(--failure);
  color: var(--failure);
}

.mini-die.is-critical {
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: 0 0 5px rgba(240, 192, 96, 0.6);
}

.mini-die.is-fumble {
  border-color: var(--failure);
  background: color-mix(in srgb, var(--failure) 18%, transparent);
}

.mini-die.is-dropped {
  opacity: 0.45;
  filter: grayscale(1);
  text-decoration: line-through;
}

.mini-dot {
  position: absolute;
  top: -3px;
  right: -3px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, #ffcf70, #e0952f);
  box-shadow: 0 0 3px rgba(224, 149, 47, 0.8);
}

.eq-op {
  color: var(--text-muted);
  padding: 0 0.1rem;
}

.eq-lit {
  color: var(--text);
  font-weight: 700;
}

.eq-var {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--accent);
}

.eq-fn {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-muted);
}

.eq-paren,
.eq-comma {
  color: var(--text-dim);
}

.eq-vs {
  font-family: var(--font-head);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  padding: 0 0.3rem;
}

.eq-dropped {
  opacity: 0.5;
}

@media (prefers-reduced-motion: no-preference) {
  .equation .grp,
  .equation .brace-grp {
    animation: chip-in 320ms cubic-bezier(0.22, 1, 0.36, 1) both;
    animation-delay: calc(150ms + var(--i) * 45ms);
  }
}

@keyframes chip-in {
  from {
    opacity: 0;
    transform: translateY(5px) scale(0.96);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/*
 * * Tray legend (playground)
 */

.tray-legend {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.3rem 0.55rem;
  font-family: var(--font-body);
  font-size: 0.8rem;
  color: var(--text-muted);
  user-select: none;
  -webkit-user-select: none;
}

.lg-item {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.lg-sep {
  color: var(--text-dim);
}

.lg-sample {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.15rem;
  height: 1.15rem;
  font-size: 0.66rem;
  font-weight: 700;
  color: var(--text);
  border: 1.5px solid var(--die-stroke);
  border-radius: 4px;
  font-variant-numeric: tabular-nums;
}

.lg-sample.is-critical {
  border-color: var(--accent);
  color: var(--accent);
}

.lg-sample.is-fumble {
  border-color: var(--failure);
  background: color-mix(in srgb, var(--failure) 18%, transparent);
}

.lg-sample.is-success {
  border-color: var(--success);
  color: var(--success);
}

.lg-sample.is-failure {
  border-color: var(--failure);
  color: var(--failure);
}

.lg-sample.is-dropped {
  opacity: 0.5;
  text-decoration: line-through;
}

/* Reuse the die badge styling inline in the legend row. */
.lg-badge {
  position: static;
  width: 1.15rem;
  height: 1.15rem;
  font-size: 0.72rem;
}

.degree-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.02em;
  border: 1px solid var(--border);
}

.degree-nat {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.8rem;
  letter-spacing: 0;
  color: var(--text-muted);
}

.deg-crit-success {
  color: var(--success);
  border-color: var(--success);
}

.deg-success {
  color: var(--success);
}

.deg-failure {
  color: var(--failure);
}

.deg-crit-failure {
  color: var(--failure);
  border-color: var(--failure);
}

/*
 * ============================================================
 * * Playground layout (index.html only)
 * ============================================================
 */

.app {
  display: flex;
  flex-direction: column;
  height: 100dvh;
  overflow: hidden;
  padding: 0 1rem;
}

.main {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  padding-top: min(28vh, 220px);
  transition: padding-top var(--transition);
}

.app.is-active .main {
  padding-top: clamp(1rem, 4vh, 2.5rem);
}

/* Top navigation — Guide/Docs pills, present in both idle and active states. */
.top-nav {
  position: fixed;
  top: calc(0.75rem - 1px);
  right: calc(0.75rem - 1px);
  z-index: 5;
  display: flex;
  gap: 0.4rem;
  user-select: none;
  -webkit-user-select: none;
}

.guide-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.75rem;
  font-family: var(--font-head);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--text-muted);
  text-decoration: none;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  transition:
    color 150ms ease,
    border-color 150ms ease,
    background 150ms ease;
}

.guide-link:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--surface-strong);
}

.guide-glyph {
  display: inline-flex;
  align-items: center;
}

.guide-glyph .icon-svg {
  width: 1.05em;
  height: 1.05em;
}

/* Theme toggle — sits in .top-nav and cycles auto → light → dark. Only the
   icon for the active mode shows, driven by the <html data-theme> attribute. */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  align-self: center;
  width: 1.95rem;
  height: 1.95rem;
  padding: 0;
  color: var(--text-muted);
  cursor: pointer;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  transition:
    color 150ms ease,
    border-color 150ms ease,
    background 150ms ease;
}

.theme-toggle:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--surface-strong);
}

.theme-icon {
  width: 1.05rem;
  height: 1.05rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.theme-icon--auto,
.theme-icon--light,
.theme-icon--dark {
  display: none;
}

:root[data-theme='auto'] .theme-icon--auto,
:root[data-theme='light'] .theme-icon--light,
:root[data-theme='dark'] .theme-icon--dark {
  display: block;
}

/*
 * * Idle logo gap
 */

/* Idle, the collapsed tray and legend leave the logo resting on the input —
   open the same gap the examples get below it. */
.app .logo {
  transition: margin-bottom var(--transition);
}

.app:not(.is-active) .logo {
  margin-bottom: 1.1rem;
}

/*
 * * Dice tray
 */

/* Single fixed-height row — never wraps, never scrolls. The extra headroom
   over `--die-size` leaves room for the -5px explode/reroll badge overhang so
   `overflow: visible` (needed for the badges) can't spawn a scrollbar. */
.tray {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  width: 100%;
  height: 0;
  opacity: 0;
  overflow: hidden;
  margin: 0;
  user-select: none;
  -webkit-user-select: none;
  transition:
    height var(--transition),
    opacity var(--transition),
    margin var(--transition);
}

.app.is-active .tray {
  height: calc(var(--die-size) + 12px);
  opacity: 1;
  margin: 1.25rem 0;
  overflow: visible;
}

/* Unfolded: wrap into as many rows as fit, then scroll. The result panel below
   is `flex: 1` with its own scroll, so it yields the space instead of clipping.
   `overflow-y` kills the badge overhang `visible` allowed — padding buys it back. */
.app.is-active .tray.is-expanded {
  flex-wrap: wrap;
  height: auto;
  max-height: 34vh;
  padding: 6px 4px;
  overflow-y: auto;
}

/* Reserved slot for the state legend — fixed height while active so legend
   content appears/disappears without nudging the input below it. */
.legend-slot {
  width: 100%;
  height: 0;
  opacity: 0;
  overflow: hidden;
  transition:
    height var(--transition),
    opacity var(--transition);
}

.app.is-active .legend-slot {
  height: 1.7rem;
  opacity: 1;
}

/*
 * * Input
 */

.input-zone {
  width: 100%;
  flex-shrink: 0;
}

.input-row {
  display: flex;
  gap: 0.5rem;
  width: 100%;
}

.input-wrap {
  position: relative;
  flex: 1;
  min-width: 0;
}

.notation-input {
  width: 100%;
  height: var(--control-h);
  font-size: 1.1rem;
  font-family: var(--font-mono);
  /* Extra right padding so typed text never runs under the clear button. */
  padding: 0 2.75rem 0 1rem;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  outline: none;
  transition:
    border-color 150ms ease,
    box-shadow 150ms ease;
}

/* Clear (×) — inside the input on the right, shown only when non-empty. */
.input-clear {
  position: absolute;
  top: 50%;
  right: 0.55rem;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 1.9rem;
  height: 1.9rem;
  padding: 0;
  /* Anchors the glyph's `em` sizing — buttons don't inherit font-size. */
  font-size: 1rem;
  color: var(--text-muted);
  background: transparent;
  border: 0;
  border-radius: 8px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  user-select: none;
  -webkit-user-select: none;
  transition:
    color 150ms ease,
    background 150ms ease,
    opacity 150ms ease;
}

.input-wrap.has-value .input-clear {
  opacity: 1;
  visibility: visible;
}

.input-clear:hover {
  color: var(--text);
  background: var(--surface-strong);
}

.input-clear .icon-svg {
  width: 1.3em;
  height: 1.3em;
}

.notation-input::placeholder {
  color: var(--text-dim);
}

.notation-input:focus-visible {
  border-color: transparent;
  box-shadow: 0 0 0 2px var(--accent);
}

.notation-input.is-invalid {
  border-color: var(--failure);
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--failure) 40%, transparent);
}

.copied-flag {
  position: absolute;
  bottom: calc(100% + 6px);
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-body);
  font-size: 0.7rem;
  padding: 2px 6px;
  border-radius: 6px;
  background: var(--text);
  color: var(--bg);
  opacity: 0;
  pointer-events: none;
  transition: opacity 150ms ease;
  white-space: nowrap;
}

.copied-flag.is-visible {
  opacity: 1;
}

/*
 * * Grouped example chips + error slot
 */

.examples {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem 1.25rem;
  margin-top: 1.1rem;
}

.app.is-active .examples {
  display: none;
}

.example-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
}

.example-label {
  font-family: var(--font-head);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  user-select: none;
  -webkit-user-select: none;
}

.example-chips {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.35rem;
}

.chip {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 0.35rem 0.65rem;
  color: var(--text-muted);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  transition:
    color 150ms ease,
    border-color 150ms ease;
}

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

.error-slot {
  margin-top: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.error-slot:empty {
  margin-top: 0;
}

/* Reserve space while active so a transient parse error appearing mid-type
   doesn't shove the result panel down. */
.app.is-active .error-slot {
  min-height: 1.5rem;
}

.error-msg {
  color: var(--failure);
  font-size: 0.9rem;
}

.error-echo {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text-muted);
  word-break: break-all;
}

/* ! `--failure` text sits on this wash, so the tint eats its own contrast.
   Measured over `--bg`, 14% holds 4.93 dark / 4.55 light; 18% drops the light
   theme to 4.29, under AA. Re-measure before raising it. */
.error-span {
  background: color-mix(in srgb, var(--failure) 14%, transparent);
  color: var(--failure);
  border-bottom: 2px solid var(--failure);
  border-radius: 2px;
}

/*
 * * Result panel
 */

.result-panel {
  flex: 1;
  min-height: 0;
  width: 100%;
  overflow-y: auto;
  margin-top: 1.5rem;
  text-align: center;
}

@media (prefers-reduced-motion: no-preference) {
  .result-panel.is-fresh {
    animation: panel-rise var(--spring) both;
  }
}

@keyframes panel-rise {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.total {
  /* fit-content keeps the gradient box tight to the digits. */
  width: fit-content;
  /* Wrap, never clip — a truncated number reads as a different number. */
  max-width: 100%;
  overflow-wrap: anywhere;
  margin: 0 auto;
  font-family: var(--font-num);
  font-size: clamp(3rem, 12vw, 5.5rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  background: var(--gold-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.success-summary {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
}

.count-item {
  display: flex;
  flex-direction: column;
  font-family: var(--font-head);
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.count-item b {
  font-family: var(--font-num);
  font-size: 3rem;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.count-success b {
  color: var(--success);
}

.count-fail b {
  color: var(--failure);
}

.result-panel .degree-badge {
  margin-bottom: 0.75rem;
}

.breakdown {
  margin: 1rem auto 0;
  max-width: 640px;
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--text);
  word-break: break-word;
}

.breakdown.too-many {
  color: var(--text-muted);
  font-style: italic;
}

.expr-note {
  margin-top: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-dim);
}

/*
 * * Footer
 */

.footer {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.9rem 0;
  font-size: 0.85rem;
  color: var(--text-dim);
}

.footer a {
  color: var(--text-muted);
  text-decoration: none;
  /* Rounds the shared focus ring; there is no painted border to round. */
  border-radius: 5px;
  transition: color 150ms ease;
}

.footer a:hover {
  color: var(--accent);
}

.footer .dot {
  opacity: 0.5;
}

/*
 * * Mobile (playground)
 */

@media (max-width: 640px) {
  .main {
    padding-top: min(18vh, 120px);
  }

  /* Logo keeps one size across states; nudge it smaller on mobile so the
     centered wordmark clears the fixed theme toggle. */
  .logo-die {
    width: 42px;
    height: 42px;
  }

  .wordmark {
    font-size: 1.3rem;
  }

  :root {
    --die-size: 40px;
    --control-h: 48px;
  }

  .notation-input {
    /* 16px+ prevents iOS from zooming the viewport on focus. */
    font-size: 16px;
  }

  .app.is-active .main {
    padding-top: 0.75rem;
  }

  /* Guide/Docs pills crowd the centered logo at this width — drop them and keep
     the theme toggle. Both stay reachable from the footer. */
  .guide-link {
    display: none;
  }

  /* Keep examples from pushing the input off-screen — only the marked groups
     survive on narrow viewports. */
  .example-group:not(.example-group--mobile) {
    display: none;
  }
}

/*
 * * Reduced motion
 */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}