/*
  Design notes
  - One memorable element: the "contents bar", a single strip split by share, drawn with
    textures (solid, stripes, dots, crosshatch) so it never relies on color alone.
  - Everything else stays quiet: system fonts, one accent for actions, no cards.
  - Monospace is used for exactly one thing: the extension itself.
*/

:root {
  --paper: #f4f6f8;
  --paper-2: #e8ecf0;
  --ink: #17212b;
  --ink-soft: #4b5a68;
  --rule: #c3ccd5;
  --tape: #2450d6;
  --tape-ink: #ffffff;
  --ok: #17724f;
  --near: #8f5400;
  --bad: #ae2a1d;

  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-ext: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --measure: 38rem;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #10161c;
    --paper-2: #1a232c;
    --ink: #e7ecf1;
    --ink-soft: #9aa9b7;
    --rule: #2f3d4a;
    --tape: #8eacff;
    --tape-ink: #0b1220;
    --ok: #52c79a;
    --near: #e0a44a;
    --bad: #ff8a7a;
  }
}

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

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.55;
}

.page {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 1rem 1rem 3rem;
}

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

a {
  color: var(--tape);
  text-underline-offset: 0.15em;
}

:focus-visible {
  outline: 3px solid var(--tape);
  outline-offset: 2px;
}

main:focus {
  outline: none;
}

/* Masthead */

.masthead {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--ink);
  margin-bottom: 1.5rem;
}

.masthead h1 {
  margin: 0;
  font-size: 1.5rem;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

/* Buttons */

.btn {
  font: inherit;
  font-size: 0.95rem;
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--ink);
  border-radius: 2px;
  padding: 0.45rem 0.8rem;
  cursor: pointer;
}

.btn:hover {
  background: var(--paper-2);
}

.btn-primary {
  background: var(--tape);
  border-color: var(--tape);
  color: var(--tape-ink);
  font-weight: 600;
}

.btn-primary:hover {
  background: var(--tape);
  filter: brightness(1.08);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 1.25rem 0 0;
}

.status {
  align-self: center;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

/* Intro */

.lede {
  font-size: 1.35rem;
  line-height: 1.35;
  margin: 0 0 1rem;
  font-weight: 600;
}

.intro p {
  margin: 0 0 0.9rem;
}

.legend {
  margin: 1.25rem 0 0;
  padding: 0;
}

.legend dt {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 600;
  margin-top: 0.9rem;
}

.legend dd {
  margin: 0.15rem 0 0 1.6rem;
  color: var(--ink-soft);
}

.legend code {
  font-family: var(--font-ext);
  font-size: 0.9em;
  color: var(--ink);
}

.hint {
  color: var(--ink-soft);
  font-size: 0.9rem;
  margin: 1rem 0 0;
}

/* Question */

.progress {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  color: var(--ink-soft);
  font-size: 0.9rem;
  margin: 0 0 1rem;
}

.ext-line {
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
  flex-wrap: wrap;
  margin: 0 0 0.25rem;
}

.ext {
  margin: 0;
  font-family: var(--font-ext);
  font-weight: 600;
  font-size: clamp(3rem, 15vw, 5.5rem);
  line-height: 1;
  letter-spacing: -0.03em;
  overflow-wrap: anywhere;
}

.ext:focus {
  outline: none;
}

.group {
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.question-prompt {
  margin: 0.5rem 0 1rem;
  color: var(--ink-soft);
}

.choices {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.choice {
  display: grid;
  grid-template-columns: auto auto 1fr auto;
  align-items: center;
  gap: 0.7rem;
  width: 100%;
  text-align: left;
  font: inherit;
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--rule);
  border-left: 4px solid var(--rule);
  border-radius: 2px;
  padding: 0.7rem 0.8rem;
  cursor: pointer;
}

.choice:hover:not(:disabled) {
  background: var(--paper-2);
  border-color: var(--ink);
}

.choice:disabled {
  cursor: default;
  color: var(--ink);
}

.choice kbd {
  font-family: var(--font-ext);
  font-size: 0.8rem;
  min-width: 1.4rem;
  text-align: center;
  padding: 0.05rem 0.3rem;
  border: 1px solid var(--rule);
  border-radius: 2px;
  color: var(--ink-soft);
}

.choice .tags {
  display: inline-flex;
  gap: 0.4rem;
  font-size: 0.8rem;
  color: var(--ink-soft);
}

.choice.is-top {
  border-left-color: var(--ok);
  border-color: var(--ok);
}

.choice.is-chosen {
  border-width: 2px;
  border-left-width: 4px;
  padding: calc(0.7rem - 1px) calc(0.8rem - 1px);
}

.choice.is-chosen:not(.is-top) {
  border-color: var(--ink);
}

/* Textures. The same six are used for bars, swatches, and share rows. */

.cat-0 { --tex-bg: var(--ink); }
.cat-1 {
  --tex-bg: repeating-linear-gradient(135deg, var(--ink) 0 2px, transparent 2px 5px);
}
.cat-2 {
  --tex-bg: radial-gradient(circle at 3px 3px, var(--ink) 1.2px, transparent 1.6px) 0 0 / 6px 6px;
}
.cat-3 {
  --tex-bg:
    repeating-linear-gradient(45deg, var(--ink-soft) 0 1px, transparent 1px 6px),
    repeating-linear-gradient(135deg, var(--ink-soft) 0 1px, transparent 1px 6px);
}
.cat-4 {
  --tex-bg: repeating-linear-gradient(0deg, var(--ink) 0 2px, transparent 2px 5px);
}
.cat-5 {
  --tex-bg: conic-gradient(var(--ink) 25%, transparent 0 50%, var(--ink) 0 75%, transparent 0) 0 0 / 8px 8px;
}

.swatch {
  display: inline-block;
  width: 1.1rem;
  height: 1.1rem;
  flex: none;
  border: 1px solid var(--ink);
  background: var(--tex-bg);
}

/* Feedback */

.feedback {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 2px solid var(--ink);
}

.verdict {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0 0 0.75rem;
}

.feedback[data-verdict="correct"] .verdict { color: var(--ok); }
.feedback[data-verdict="close"] .verdict { color: var(--near); }
.feedback[data-verdict="wrong"] .verdict { color: var(--bad); }

/* Row: shared by quiz feedback and reference mode */

.row {
  margin: 0 0 1.75rem;
}

.row.is-target {
  outline: 3px solid var(--tape);
  outline-offset: 6px;
}

.row-head {
  display: flex;
  align-items: baseline;
  gap: 0.8rem;
  margin: 0 0 0.5rem;
}

.row-head .ext {
  font-size: 2rem;
  letter-spacing: -0.02em;
}

.contents {
  display: flex;
  width: 100%;
  height: 1.6rem;
  border: 1px solid var(--ink);
  background: var(--paper);
  overflow: hidden;
}

.seg {
  min-width: 2px;
  background: var(--tex-bg);
  border-right: 1px solid var(--ink);
}

.seg:last-child {
  border-right: 0;
}

.shares {
  list-style: none;
  margin: 0.6rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.2rem;
}

.share {
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.95rem;
}

.share .pct {
  font-variant-numeric: tabular-nums;
  text-align: right;
  min-width: 3ch;
}

.share .flag {
  font-size: 0.8rem;
  color: var(--ink-soft);
  min-width: 6.5rem;
}

.share.is-top {
  font-weight: 700;
}

.share.is-top .flag {
  color: var(--ok);
  font-weight: 700;
}

.note {
  margin: 0.8rem 0 0.3rem;
}

.meta {
  margin: 0.2rem 0 0;
  color: var(--ink-soft);
  font-size: 0.88rem;
}

.meta a {
  margin-right: 0.2rem;
}

/* Debug panel */

.debug {
  margin: 0 0 1rem;
  border-left: 2px solid var(--rule);
  padding-left: 0.8rem;
}

.debug summary {
  cursor: pointer;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.debug pre {
  margin: 0.5rem 0 0;
  font-family: var(--font-ext);
  font-size: 0.82rem;
  line-height: 1.5;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

/* Results */

.total {
  font-size: clamp(2.5rem, 12vw, 4rem);
  font-weight: 700;
  line-height: 1;
  margin: 0;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}

.percent {
  color: var(--ink-soft);
  margin: 0.25rem 0 0.75rem;
}

.marks {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0;
  font-family: var(--font-ext);
  font-size: 1.1rem;
}

.mark[data-verdict="correct"] { color: var(--ok); }
.mark[data-verdict="close"] { color: var(--near); }
.mark[data-verdict="wrong"] { color: var(--bad); }

.table-wrap {
  overflow-x: auto;
  margin-top: 1.5rem;
}

.debug-table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.85rem;
  font-variant-numeric: tabular-nums;
}

.debug-table th,
.debug-table td {
  text-align: left;
  padding: 0.3rem 0.6rem 0.3rem 0;
  border-bottom: 1px solid var(--rule);
  white-space: nowrap;
}

.debug-table th {
  color: var(--ink-soft);
  font-weight: 600;
}

/* Reference */

.ref-intro {
  color: var(--ink-soft);
  margin: 0 0 0.5rem;
}

.group-title {
  font-size: 1.1rem;
  margin: 2rem 0 1rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--rule);
}

h2.screen-title {
  font-size: 1.35rem;
  margin: 0 0 0.5rem;
}

/* Colophon */

.colophon {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  color: var(--ink-soft);
  font-size: 0.85rem;
}

.colophon p {
  margin: 0;
}

/* Motion: only the bar reveal after a person answers. */

@media (prefers-reduced-motion: no-preference) {
  .feedback .seg {
    animation: grow 0.45s ease-out;
  }

  @keyframes grow {
    from { flex-grow: 0; }
  }
}

@media (max-width: 26rem) {
  .choice {
    grid-template-columns: auto auto 1fr;
  }

  .choice .tags {
    grid-column: 3;
  }

  .share {
    grid-template-columns: auto 1fr auto;
  }

  .share .flag {
    grid-column: 2 / -1;
    min-width: 0;
  }
}