.demo-page {
  max-width: 1120px;
  margin-inline: auto;
  padding: 48px 24px 56px;
  color: var(--text);
  font-family: var(--font-sans);
}
.demo-page *, .demo-page *::before, .demo-page *::after { box-sizing: border-box; }
.demo-page [hidden] { display: none !important; }
.demo-page h1, .demo-page h2, .demo-page h3, .demo-page p { margin: 0; }
.demo-page button, .demo-page input { font: inherit; }
.demo-page button { cursor: pointer; }
.demo-page button:disabled { cursor: default; opacity: .55; }
.demo-page :focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
.demo-intro { max-width: 760px; margin-bottom: 32px; }
.demo-question-position { font-size: .8rem; font-weight: 600; color: var(--muted); }
.demo-intro h1 { margin: 0 0 14px; font-size: clamp(1.85rem, 3.5vw, 2.75rem); font-weight: 620; line-height: 1.15; letter-spacing: -.035em; text-wrap: balance; }
.demo-intro > p { line-height: 1.65; color: var(--muted); }
.demo-intro .demo-disclosure { margin-top: 9px; font-size: .8rem; }
.demo-workspace { display: grid; grid-template-columns: minmax(0, 1fr) 200px; border: 1px solid var(--line); border-radius: 16px; overflow: clip; background: var(--surface); }
.demo-session { padding: 26px 20px; background: var(--page); border-left: 1px solid var(--line); }
.demo-session-heading h2 { display: flex; align-items: center; gap: 8px; font-size: 1rem; font-weight: 650; letter-spacing: -.015em; }
.demo-sample-label { display: block; margin-top: 5px; color: var(--muted); font-size: .75rem; }
.demo-progress-label { display: flex; justify-content: space-between; gap: 8px; margin-top: 28px; font-size: .7rem; color: var(--muted); }
.demo-progress-label span { font-variant-numeric: tabular-nums; white-space: nowrap; }
.demo-progress { width: 100%; height: 5px; margin: 10px 0 24px; border: 0; border-radius: 9px; overflow: hidden; background: var(--line); accent-color: var(--accent); display: block; }
.demo-progress::-webkit-progress-bar { background: var(--line); }
.demo-progress::-webkit-progress-value { background: var(--accent); }
.demo-progress::-moz-progress-bar { background: var(--accent); }
.demo-question-nav { padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; list-style: none; }
.demo-nav-button { width: 100%; min-height: 52px; border: 1px solid var(--line); border-radius: 9px; background: var(--surface); color: var(--text); display: flex; align-items: center; justify-content: center; gap: 4px; position: relative; font-size: .95rem; font-weight: 600; font-variant-numeric: tabular-nums; }
.demo-nav-button[aria-current="step"] { outline: 2px solid var(--accent); outline-offset: 2px; }
.demo-nav-button[data-outcome="correct"] { border-color: var(--correct); color: var(--correct); background: color-mix(in srgb, var(--correct) 7%, var(--surface)); }
.demo-nav-button[data-outcome="incorrect"] { border-color: var(--incorrect); color: var(--incorrect); background: color-mix(in srgb, var(--incorrect) 7%, var(--surface)); }
.demo-icon { width: 18px; height: 18px; flex: 0 0 auto; fill: none; stroke: currentColor; stroke-width: 1.75; stroke-linecap: round; stroke-linejoin: round; vertical-align: middle; }
.demo-icon.demo-nav-mark { width: 12px; height: 12px; }
.demo-icon.demo-nav-flag { position: absolute; right: 3px; top: 3px; width: 11px; height: 11px; color: var(--muted); }
.demo-nav-hint { font-size: .73rem; line-height: 1.6; margin-top: 14px !important; color: var(--muted); }
.demo-session > .demo-button { margin-top: 24px; width: 100%; font-size: .8rem; }
.demo-panel { min-width: 0; padding: 26px 34px 24px; }
.demo-question-meta { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px; margin-bottom: 26px; }
.demo-flag { display: inline-flex; align-items: center; gap: 6px; min-height: 44px; padding: 8px 10px; border: 1px solid transparent; border-radius: 9px; background: transparent; color: var(--muted); font-size: .76rem !important; }
.demo-flag[aria-pressed="true"] { color: var(--accent-ink); background: color-mix(in srgb, var(--accent) 8%, var(--surface)); border-color: var(--line); }
.demo-topic { margin-bottom: 10px !important; color: var(--muted); font-size: .78rem; }
.demo-question-title { max-width: 70ch; font-family: var(--font-serif); font-size: clamp(1.2rem, 2.2vw, 1.48rem); line-height: 1.6; letter-spacing: 0; font-weight: 400; text-wrap: pretty; }
.demo-filter-bar { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 6px 14px; margin: -8px 0 20px; padding: 10px 12px; border-radius: 9px; background: var(--page); font-size: .78rem; }
.demo-options-fieldset { border: 0; margin: 25px 0 0; padding: 0; min-width: 0; }
.demo-options-fieldset legend { padding: 0; margin-bottom: 12px; color: var(--muted); font-size: .78rem; }
.demo-options { display: grid; gap: 10px; }
.demo-option { display: grid; grid-template-columns: 18px 20px minmax(0, 1fr); align-items: start; gap: 6px 12px; padding: 14px 16px; border: 1px solid var(--line); border-radius: 9px; min-height: 52px; line-height: 1.5; cursor: pointer; }
.demo-answer-label { padding-top: 2px; font-size: .86rem; color: var(--muted); }
.demo-answer-text { font-family: var(--font-serif); font-size: 1.125rem; line-height: 1.5; }
.demo-option input { flex: 0 0 auto; width: 17px; height: 17px; margin: 4px 0 0; accent-color: var(--outcome-color, var(--accent)); }
.demo-option:not([data-outcome]):has(input:checked) { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 6%, var(--surface)); }
.demo-option:has(input:disabled) { cursor: default; }
.demo-option[data-outcome="correct"] { --outcome-color: var(--correct); border-color: var(--correct); background: color-mix(in srgb, var(--correct) 6%, var(--surface)); }
.demo-option[data-outcome="incorrect"] { --outcome-color: var(--incorrect); border-color: var(--incorrect); background: color-mix(in srgb, var(--incorrect) 6%, var(--surface)); }
.demo-option-answer { grid-column: 3; display: flex; align-items: center; gap: 6px; font-family: var(--font-sans); font-size: .75rem; font-weight: 600; color: var(--outcome-color); }
.demo-option-answer .demo-icon { width: 14px; height: 14px; }
.demo-answer-actions { display: flex; align-items: center; gap: 16px; margin-top: 22px; }
.demo-answer-actions p { color: var(--muted); font-size: .72rem; line-height: 1.5; max-width: 220px; }
.demo-button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 44px; border: 1px solid var(--accent-ink); border-radius: 9px; padding: 11px 17px; background: var(--accent-ink); color: var(--button-text); font-size: .83rem !important; font-weight: 600; line-height: 1.35; text-align: center; }
.demo-button-secondary { border-color: var(--line); background: var(--surface); color: var(--text); }
.demo-button:not(:disabled):hover { background: color-mix(in oklch, var(--accent-ink) 90%, var(--text)); }
.demo-button-secondary:not(:disabled):hover, .demo-nav-button:hover { background: var(--page); }
.demo-text-button { min-height: 44px; padding: 8px 0; border: 0; background: transparent; color: var(--accent-ink); font-size: .78rem !important; text-decoration: underline; text-underline-offset: 3px; text-align: left; }
.demo-question-footer { display: flex; justify-content: space-between; gap: 12px; border-top: 1px solid var(--line); padding-top: 20px; margin-top: 28px; }
.demo-feedback { margin-top: 24px; padding-top: 20px; border-top: 1px solid var(--line); line-height: 1.65; }
.demo-feedback[data-outcome="correct"] { --outcome-color: var(--correct); }
.demo-feedback[data-outcome="incorrect"] { --outcome-color: var(--incorrect); }
.demo-feedback p { max-width: 70ch; font-family: var(--font-serif); font-size: 1.125rem; line-height: 1.7; }
.demo-feedback h3 { display: flex; align-items: center; gap: 8px; font-family: var(--font-sans); font-size: .94rem; margin-bottom: 10px; color: var(--outcome-color); }
.demo-feedback p + p { margin-top: 7px; }
.demo-reference { margin-top: 18px; }
.demo-reference table { width: 100%; font-family: var(--font-serif); border-collapse: collapse; font-size: 1rem; line-height: 1.5; }
.demo-reference caption { text-align: left; font-family: var(--font-sans); color: var(--muted); margin-bottom: 8px; font-size: .75rem; }
.demo-reference th, .demo-reference td { border-bottom: 1px solid var(--line); padding: 9px 7px; text-align: left; }
.demo-reference thead th { font-family: var(--font-sans); color: var(--muted); font-size: .8rem; font-weight: 500; }
.demo-reference tbody th { font-weight: 500; }
.demo-summary { padding-block: 14px 4px; }
.demo-summary h2 { margin: 16px 0 24px; font-size: 1.6rem; line-height: 1.25; letter-spacing: -.025em; }
.demo-score { font-size: clamp(2.6rem, 6vw, 4rem); font-weight: 600; line-height: 1; letter-spacing: -.035em; font-variant-numeric: tabular-nums; }
.demo-score[data-empty="true"] { font-size: 1.6rem; line-height: 1.3; letter-spacing: -.025em; }
.demo-score-caption { margin-top: 10px !important; color: var(--muted); font-size: .82rem; }
.demo-summary-counts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; margin: 28px 0; padding-block: 18px; border-block: 1px solid var(--line); }
.demo-summary-counts dt { color: var(--muted); font-size: .75rem; }
.demo-summary-counts dd { margin: 7px 0 0; font-size: 1.3rem; font-variant-numeric: tabular-nums; }
.demo-summary > p:not(.demo-score):not(.demo-score-caption) { font-size: .86rem; line-height: 1.65; }
.demo-summary-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.demo-summary-note { margin-top: 24px !important; color: var(--muted); }
.demo-storage { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; padding-top: 20px; }
.demo-storage p { max-width: 610px; font-size: .73rem; line-height: 1.7; color: var(--muted); }
.demo-storage .demo-text-button { flex-shrink: 0; padding-top: 0; min-height: 44px; }
.demo-status { min-height: 1.5em; margin-top: 8px !important; color: var(--muted); font-size: .78rem; line-height: 1.6; }
.demo-notice { border: 1px solid var(--line); border-radius: 10px; padding: 24px; line-height: 1.7; }
@media (max-width: 760px) {
  .demo-page { padding-top: 32px; }
  .demo-workspace { grid-template-columns: 1fr; }
  .demo-session { border-left: 0; border-top: 1px solid var(--line); padding: 20px; }
  .demo-session-heading { display: flex; align-items: baseline; justify-content: space-between; flex-wrap: wrap; gap: 6px; }
  .demo-sample-label { margin: 0; }
  .demo-progress-label { margin-top: 18px; }
  .demo-progress { margin-bottom: 16px; }
  .demo-question-nav { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .demo-nav-button { min-height: 44px; }
  .demo-session > .demo-button { width: auto; margin-top: 14px; }
  .demo-panel { padding: 22px; }
  .demo-question-meta { margin-bottom: 18px; }
  .demo-storage { flex-direction: column; gap: 8px; }
}
@media (max-width: 430px) {
  .demo-page { padding-inline: 18px; }
  .demo-panel, .demo-session { padding: 18px; }
  .demo-question-nav { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .demo-answer-actions { align-items: flex-start; flex-direction: column; gap: 9px; }
  .demo-option { padding: 12px; column-gap: 8px; }
  .demo-question-footer .demo-button { padding-inline: 12px; }
  .demo-summary-actions { flex-direction: column; }
}