.arena-demo {
  min-inline-size: 0;
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  container-type: inline-size;
  font-family: var(--font-body);
}
.arena-demo *, .arena-demo *::before, .arena-demo *::after { box-sizing: border-box; }
.arena-demo p, .arena-demo h2, .arena-demo h3, .arena-demo h4, .arena-demo h5 { margin: 0; }
.arena-demo__head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-6);
  padding: var(--space-5) var(--space-6);
  background: var(--color-surface-inverse);
  color: var(--color-text-inverse);
  border-radius: calc(var(--radius-md) - 1px) calc(var(--radius-md) - 1px) 0 0;
}
.arena-demo__head strong { font-size: var(--type-h3); font-weight: 600; }
.arena-demo__head > span { color: var(--color-text-inverse-secondary); font-size: var(--type-body-sm); }
.arena-demo__steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-4);
  margin: 0;
  padding: var(--space-4) var(--space-6) 0;
  list-style: none;
  background: var(--color-bg-subtle);
}
.arena-demo__steps li {
  padding-block-end: var(--space-3);
  border-block-end: 3px solid transparent;
  color: var(--color-text-secondary);
  font-size: var(--type-body-sm);
  line-height: 1.4;
  transition: border-color var(--duration-fast) var(--ease-standard), color var(--duration-fast) var(--ease-standard);
}
.arena-demo__steps li[aria-current] { border-color: var(--color-brand); color: var(--color-text); font-weight: 600; }
.arena-demo__stage { padding: clamp(1rem, 3cqi, 2rem); }
.arena-demo__setup-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, .9fr); gap: clamp(1.5rem, 4cqi, 3rem); align-items: center; }
.arena-demo__setup { display: grid; gap: var(--space-4); }
.arena-demo .arena-demo__title { color: var(--color-text); font-size: var(--type-h2); line-height: 1.2; font-weight: 600; text-wrap: balance; max-inline-size: 30ch; }
.arena-demo__setup > p { max-inline-size: 52ch; color: var(--color-text-secondary); font-size: var(--type-body); line-height: 1.55; }
.arena-demo__modes, .arena-demo__answers { min-inline-size: 0; padding: 0; border: 0; margin: 0; }
.arena-demo__modes { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-3); }
.arena-demo__modes legend { margin-block-end: var(--space-3); font-size: var(--type-body-sm); font-weight: 600; }
.arena-demo__mode { display: flex; align-items: flex-start; gap: var(--space-2); padding: var(--space-3); border: 1px solid var(--color-border-strong); border-radius: var(--radius-sm); cursor: pointer; }
.arena-demo__mode:has(input:checked) { background: var(--color-brand-subtle); border-color: var(--color-brand); }
.arena-demo input { accent-color: var(--color-brand); inline-size: 1rem; block-size: 1rem; margin: .2rem 0 0; flex-shrink: 0; }
.arena-demo__mode strong { display: block; font-weight: 600; font-size: var(--type-body); }
.arena-demo__mode small { display: block; margin-block-start: var(--space-1); color: var(--color-text-secondary); font-size: var(--type-caption); line-height: 1.4; }
.arena-demo .arena-demo__mode-copy { min-block-size: 4.65em; font-size: var(--type-body-sm); }
.arena-demo__timing { display: flex; align-items: center; gap: var(--space-3); min-block-size: var(--control-height); font-size: var(--type-body-sm); cursor: pointer; }
.arena-demo__timing input { margin: 0; }
.arena-demo__button {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  min-block-size: var(--control-height);
  padding: var(--space-3) var(--space-5);
  border: 1px solid var(--color-brand);
  border-radius: var(--radius-sm);
  background: var(--color-brand);
  color: var(--color-text-inverse);
  font: 600 var(--type-body-sm)/1.3 var(--font-body);
  text-align: center;
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-standard), border-color var(--duration-fast) var(--ease-standard);
}
.arena-demo__setup > .arena-demo__button { justify-self: start; }
.arena-demo__button--quiet { border-color: var(--color-border-strong); background: transparent; color: var(--color-text); }
.arena-demo__button:disabled { color: var(--color-disabled); background: var(--color-disabled-bg); border-color: var(--color-border); cursor: not-allowed; }
.arena-demo :focus-visible { outline: 2px solid var(--color-focus); outline-offset: 3px; }
.arena-demo__mode:has(input:focus-visible), .arena-demo__option:has(input:focus-visible) { outline: 2px solid var(--color-focus); outline-offset: 3px; }
.arena-demo .arena-demo__meta { color: var(--color-text-secondary); font: 500 var(--type-body-sm)/1.5 var(--font-body); }
.arena-demo__figure { margin: var(--space-3) 0 0; }
.arena-demo__figure > a { display: block; cursor: zoom-in; background: var(--color-bg-subtle); border: 1px solid var(--color-border); }
.arena-demo__figure img { display: block; inline-size: 100%; block-size: auto; max-block-size: 23rem; object-fit: contain; }
.arena-demo__image-error { display: grid; justify-items: start; gap: var(--space-3); padding: var(--space-5); border: 1px solid var(--color-error); color: var(--color-error); background: var(--color-error-subtle); font-size: var(--type-body-sm); line-height: 1.5; }
.arena-demo [hidden] { display: none; }
.arena-demo__figure figcaption { display: grid; gap: var(--space-1); padding-block: var(--space-2); color: var(--color-text-secondary); font-size: var(--type-caption); line-height: 1.45; }
.arena-demo__image-caption { display: flex; justify-content: space-between; flex-wrap: wrap; gap: var(--space-1) var(--space-4); align-items: center; }
.arena-demo .arena-demo__image-credit { display: flex; align-items: center; flex-wrap: wrap; gap: var(--space-1) var(--space-4); max-inline-size: none; font-size: inherit; }
.arena-demo__figure figcaption a { display: inline-flex; align-items: center; min-block-size: var(--space-6); }
.arena-demo .arena-demo__preview-note { margin-block-start: var(--space-3); color: var(--color-text-secondary); font-size: var(--type-body-sm); line-height: 1.5; max-inline-size: 44ch; }
.arena-demo__round { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: var(--space-2) var(--space-4); margin-block-end: var(--space-4); }
.arena-demo__clock { font-size: var(--type-body-sm); font-weight: 600; font-variant-numeric: tabular-nums; }
.arena-demo__clock-track { block-size: 3px; margin-block: calc(-1 * var(--space-2)) var(--space-6); background: var(--color-border); overflow: hidden; }
.arena-demo__clock-track span { display: block; block-size: 100%; background: var(--color-brand); transform-origin: left; transition: transform var(--duration-normal) linear; }
.arena-demo__question-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(1.5rem, 3cqi, 2.5rem); align-items: start; }
.arena-demo .arena-demo__stem { margin-block-start: var(--space-2); font-family: var(--font-clinical); font-size: var(--type-clinical); line-height: 1.55; }
.arena-demo__decision .arena-demo__title { font-size: var(--type-body-lg); font-family: var(--font-clinical); line-height: 1.45; max-inline-size: none; }
.arena-demo__answers { display: grid; gap: var(--space-2); margin-block-start: var(--space-4); }
.arena-demo__option { position: relative; display: grid; grid-template-columns: 1rem 1.25rem minmax(0, 1fr); align-items: start; gap: var(--space-2); min-block-size: var(--control-height); border: 1px solid var(--color-border-strong); border-radius: var(--radius-sm); padding: var(--space-3); cursor: pointer; transition: background-color var(--duration-fast) var(--ease-standard), border-color var(--duration-fast) var(--ease-standard); }
.arena-demo__option-copy { font-family: var(--font-clinical); font-size: var(--type-clinical); line-height: 1.4; }
.arena-demo__option-key { font-weight: 600; line-height: 1.5; }
.arena-demo__option:has(input:checked) { background: var(--color-brand-subtle); border-color: var(--color-brand); }
.arena-demo__option:has(input:disabled) { cursor: default; }
.arena-demo[data-phase="review"] .arena-demo__option.is-correct { background: var(--color-success-subtle); border-color: var(--color-success); }
.arena-demo[data-phase="review"] .arena-demo__option.is-wrong { background: var(--color-error-subtle); border-color: var(--color-error); }
.arena-demo__option-result { grid-column: 3; font-size: var(--type-caption); font-weight: 600; color: var(--color-error); }
.arena-demo__option.is-correct .arena-demo__option-result { color: var(--color-success); }
.arena-demo__actions { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-3); margin-block-start: var(--space-5); }
.arena-demo__locked { display: grid; justify-items: start; gap: var(--space-3); margin-block-start: var(--space-5); padding-block-start: var(--space-4); border-block-start: 1px solid var(--color-border); }
.arena-demo__locked p { font-size: var(--type-body-sm); line-height: 1.55; color: var(--color-text-secondary); }
.arena-demo__sources { margin-block-start: var(--space-3); font-size: var(--type-caption); line-height: 1.5; color: var(--color-text-secondary); }
.arena-demo__sources summary { cursor: pointer; min-block-size: var(--control-height); padding-block: var(--space-3); color: var(--color-text); }
.arena-demo__sources p + p { margin-block-start: var(--space-2); }
.arena-demo__source-links { display: flex; flex-wrap: wrap; gap: var(--space-4); }
.arena-demo a { color: var(--color-link); text-underline-offset: .2em; text-decoration-thickness: 1px; }
.arena-demo__text-link { display: inline-flex; min-block-size: var(--control-height); align-items: center; font-size: var(--type-body-sm); }
.arena-demo__teaching { margin-block-start: var(--space-6); padding: var(--space-5) 0 0; border-block-start: 2px solid var(--color-border-strong); }
.arena-demo__result { display: flex; align-items: baseline; justify-content: space-between; flex-wrap: wrap; gap: var(--space-2) var(--space-4); }
.arena-demo__result > strong { font-size: var(--type-h3); }
.arena-demo__points { color: var(--color-link); font-size: var(--type-h3); font-weight: 600; font-variant-numeric: tabular-nums; }
.arena-demo .arena-demo__score-note { margin-block: var(--space-2) var(--space-5); max-inline-size: 70ch; color: var(--color-text-secondary); font-size: var(--type-body-sm); line-height: 1.5; }
.arena-demo__teaching h3, .arena-demo__teaching h4, .arena-demo__teaching h5, .arena-demo__teaching h6 { font: 600 var(--type-body)/1.5 var(--font-body); }
.arena-demo .arena-demo__reasoning { max-inline-size: 76ch; margin-block-start: var(--space-2); font: var(--type-clinical)/1.6 var(--font-clinical); }
.arena-demo__reference { display: inline-block; margin-block-start: var(--space-3); font-size: var(--type-body-sm); }
.arena-demo .arena-demo__disclosure { max-inline-size: none; padding: var(--space-4) var(--space-6); border-block-start: 1px solid var(--color-border); background: var(--color-bg-subtle); color: var(--color-text-secondary); font-size: var(--type-caption); line-height: 1.55; border-radius: 0 0 calc(var(--radius-md) - 1px) calc(var(--radius-md) - 1px); }
.arena-demo__loading { min-block-size: 20rem; padding: var(--space-6); display: grid; place-content: center; justify-items: start; gap: var(--space-4); }
.arena-demo__status { position: absolute; inline-size: 1px; block-size: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
@media (hover: hover) {
  .arena-demo__button:not(:disabled):hover { background: var(--color-brand-hover); border-color: var(--color-brand-hover); }
  .arena-demo__button--quiet:not(:disabled):hover { color: var(--color-text); background: var(--color-bg-subtle); border-color: var(--color-border-strong); }
  .arena-demo__option:not(:has(input:disabled)):hover, .arena-demo__mode:hover { border-color: var(--color-text); }
}
@container (max-width: 700px) {
  .arena-demo__setup-grid, .arena-demo__question-grid { grid-template-columns: minmax(0, 1fr); }
  .arena-demo__first-case { padding-block-start: var(--space-5); border-block-start: 1px solid var(--color-border); }
  .arena-demo__first-case .arena-demo__figure img { max-block-size: 18rem; }
  .arena-demo__setup { gap: var(--space-3); }
  .arena-demo .arena-demo__mode-copy { min-block-size: auto; }
  .arena-demo__head, .arena-demo__disclosure { padding-inline: var(--space-4); }
  .arena-demo__steps { padding-inline: var(--space-4); gap: var(--space-3); }
}
@media (prefers-reduced-motion: no-preference) {
  .arena-demo[data-phase="question"] .arena-demo__question-grid, .arena-demo[data-phase="review"] .arena-demo__teaching { animation: arena-demo-enter var(--duration-slow) var(--ease-out) both; }
  .arena-demo[data-phase="locked"] .arena-demo__locked { animation: arena-demo-enter var(--duration-normal) var(--ease-out) both; }
  .arena-demo[data-phase="review"] .arena-demo__points { animation: arena-demo-enter var(--duration-slow) var(--ease-out) both; }
  @keyframes arena-demo-enter { from { opacity: .4; transform: translateY(5px); } to { opacity: 1; transform: none; } }
}
@media (prefers-reduced-motion: reduce) {
  .arena-demo *, .arena-demo *::before, .arena-demo *::after { animation: none; transition: none; }
}