.challenges-page .shell { max-width: 1100px; padding: 20px 0 36px; grid-template-columns: minmax(0, 1fr); }
.challenges-page main { padding: 26px 10px; min-width: 0; }
.challenges-page a { color: var(--accent-strong); text-underline-offset: 4px; }
.challenges-page h1 { line-height: 1.12; margin: 10px 0 18px; overflow-wrap: anywhere; }
.challenges-page h2 { line-height: 1.2; overflow-wrap: anywhere; }
.challenges-page .landing-header { position: static; padding: 0 10px; }
.challenges-page .landing-nav { justify-content: flex-start; flex-wrap: wrap; }
.challenges-page .locale-nav { margin-left: auto; }
.challenge-brand { flex-shrink: 0; }
.challenge-navigation { flex: 1; min-width: 0; }
.challenge-navigation > summary { display: none; }
.challenges-page .lede { margin-bottom: 24px; }
.challenge-card { border-radius: var(--radius); overflow: hidden; padding: 16px; min-width: 0; }
.challenge-featured { margin-top: 24px; display: grid; grid-template-columns: minmax(240px, 360px) 1fr; grid-template-areas: "board intro" "board action" "board meta"; align-items: center; gap: 12px 28px; padding: 24px; }
.challenge-featured .challenge-board-preview { grid-area: board; }
.challenge-intro { grid-area: intro; }
.challenge-action { grid-area: action; display: grid; gap: 12px; }
.challenge-meta { grid-area: meta; display: grid; gap: 8px; }
.challenge-intro h2 { font-size: clamp(1.25rem, 2.4vw, 1.8rem); }
.challenge-intro h2 a { color: var(--ink); text-decoration: none; }
.challenge-position-facts strong { color: var(--accent-strong); }
.challenge-archive-intro { margin-top: 24px; }
.challenge-board-link { display: block; }
.challenge-board-preview { position: relative; min-width: 0; }
/* Use the card's existing gutter so the bar never reduces the board's width. */
.challenge-evaluation { position: absolute; top: 0; bottom: 0; left: -12px; width: 8px; overflow: hidden; border: 1px solid #496078; border-radius: 3px; background: #263342; }
.challenge-evaluation-fill { position: absolute; inset: auto 0 0; height: var(--hero-percent); background: #f3ecdf; }
.challenge-evaluation[data-side='b'] { background: #f3ecdf; }
.challenge-evaluation[data-side='b'] .challenge-evaluation-fill { background: #263342; }
.challenge-board-link img { display: block; width: 100%; height: auto; aspect-ratio: 1; border-radius: 8px; }
.challenge-content { display: grid; grid-template-columns: minmax(0, 1fr); gap: 12px; min-width: 0; }
.challenge-content h2 { font-size: clamp(1.25rem, 2.4vw, 1.8rem); overflow-wrap: anywhere; }
.challenge-content h2 a { color: var(--ink); text-decoration: none; }
.challenge-content h3 { margin: 4px 0 0; font-size: 1.1rem; }
.challenge-content p { line-height: 1.5; }
.challenge-featured p { line-height: 1.4; }
.challenge-context, .challenge-date, .challenge-calendar-note { color: var(--muted); font-size: .9rem; }
.challenge-advantage strong { color: var(--accent-strong); }
.challenge-play-form { display: grid; gap: 12px; }
.challenge-play-form label { display: grid; gap: 8px; }
.challenge-play-form button { width: 100%; }
.challenge-difficulty { min-width: 0; width: min(100%, 380px); border: 0; margin: 0; padding: 0; }
.challenge-difficulty legend { width: 100%; padding: 0; margin-bottom: 6px; }
.challenge-difficulty-heading { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 2px 8px; }
.challenge-time { color: var(--muted); font-size: .78rem; }
.challenge-difficulty-options { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 2px; padding: 3px; border: 1px solid #496078; border-radius: 10px; background: #0b1826; }
.challenge-difficulty-options label { position: relative; display: flex; align-items: center; justify-content: center; min-width: 0; min-height: 44px; padding: 4px; border: 1px solid transparent; border-radius: 7px; color: var(--muted); font-size: .875rem; font-weight: 650; cursor: pointer; }
.challenge-difficulty-options input { position: absolute; inset: 0; width: 100%; height: 100%; opacity: 0; margin: 0; cursor: pointer; }
.challenge-difficulty-options label:has(input:checked) { color: var(--accent-strong); background: #d9a85b20; border-color: var(--accent); }
.challenge-difficulty-options label:has(input:focus-visible) { outline: 2px solid var(--accent-strong); outline-offset: 2px; }
.challenge-source-note { line-height: 1.6; color: var(--muted); margin: 24px 0; max-width: 760px; }
.challenge-explore { display: inline-block; margin: 0 0 4px; }
#archive { margin-top: 32px; }
.challenge-filters { border-radius: 20px; padding: 16px; margin: 16px 0; }
.challenge-filter-main { display: flex; align-items: center; gap: 12px; }
.challenge-search-field { flex: 1; }
.challenge-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; }
.challenge-clear { white-space: nowrap; }
.challenge-filter-details { margin-top: 10px; }
.challenge-filter-details summary { color: var(--accent-strong); cursor: pointer; width: fit-content; padding: 6px 2px; }
.challenge-filter-count { display: inline-block; min-width: 22px; text-align: center; border-radius: 999px; background: rgba(217,168,91,.16); color: var(--ink); font-size: .8em; }
.challenge-filter-advanced { display: grid; gap: 18px; padding-top: 18px; margin-top: 8px; border-top: 1px solid var(--border); }
.challenge-filters label { display: grid; gap: 8px; min-width: 0; }
.challenge-filters input[type="search"], .challenge-filters input[type="date"] { min-width: 0; width: 100%; min-height: 44px; padding: 10px; background: var(--bg); border: 1px solid var(--border); border-radius: 10px; color: var(--ink); font: inherit; }
.challenge-filters fieldset { margin: 0; padding: 0; border: 0; min-width: 0; }
.challenge-filters legend { margin-bottom: 10px; }
.challenge-dates { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.challenge-buckets { display: flex; flex-wrap: wrap; gap: 8px; }
.challenge-buckets label { display: flex; align-items: center; gap: 6px; border: 1px solid var(--border); border-radius: 10px; padding: 8px 10px; min-height: 44px; cursor: pointer; }
.challenge-buckets label:has(input:checked) { border-color: var(--accent); background: rgba(217,168,91,.12); }
.challenge-buckets input { accent-color: var(--accent); width: 16px; height: 16px; }
.challenge-filter-advanced .challenge-calendar-note { margin: 0; }
.challenge-result-count { margin: 20px 0; color: var(--muted); }
.challenge-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.challenge-grid .challenge-content { margin-top: 16px; }
.challenge-grid h2 { font-size: 1.2rem; }
.challenge-link { display: inline-block; padding: 12px 18px; border-radius: 12px; text-align: center; text-decoration: none; overflow-wrap: anywhere; hyphens: auto; }
.challenge-pagination, .challenge-footer { display: flex; gap: 20px; flex-wrap: wrap; align-items: center; margin-top: 28px; }
.challenge-footer { padding: 20px 10px; border-top: 1px solid var(--border); }
.challenge-empty { padding: 24px; line-height: 1.6; grid-column: 1 / -1; }
.challenges-page :focus-visible { outline: 2px solid var(--accent-strong); outline-offset: 4px; }
#archive { scroll-margin-top: 20px; }
@media (max-width: 760px) {
  .challenge-featured { grid-template-columns: minmax(160px, 260px) 1fr; gap: 12px 18px; padding: 16px; }
  .challenge-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
  .challenge-filter-main { flex-wrap: wrap; }
  .challenge-search-field { flex-basis: 100%; }
}
@media (max-width: 540px) {
  .challenges-page .shell { padding-top: 4px; gap: 4px; }
  .challenges-page main { padding: 4px 0 26px; }
  .challenges-page .shell .landing-header { flex-direction: row; align-items: center; justify-content: space-between; padding: 0 4px; border: 0; }
  .challenge-brand { display: inline-flex; align-items: center; min-height: 44px; font-size: .9375rem; text-decoration: none; }
  .challenge-navigation { position: relative; flex: none; }
  .challenge-navigation > summary { display: flex; align-items: center; justify-content: center; gap: 8px; min-height: 44px; padding: 6px 10px; border: 1px solid var(--border); border-radius: 10px; color: var(--ink); list-style: none; cursor: pointer; }
  .challenge-navigation > summary::-webkit-details-marker { display: none; }
  .challenge-navigation .landing-nav { position: absolute; z-index: 5; top: calc(100% + 6px); right: 0; width: min(320px, calc(100vw - 28px)); padding: 12px; gap: 4px 12px; border: 1px solid var(--border); border-radius: 12px; background: var(--panel); box-shadow: 0 12px 28px #0008; }
  .challenge-navigation .landing-nav > a { flex-basis: 100%; }
  .challenges-page main > .eyebrow, .challenges-page main > h1 { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
  .challenge-featured { margin-top: 0; grid-template-columns: minmax(0, 1fr); grid-template-areas: "intro" "board" "action" "meta"; gap: 8px; padding: 10px; --challenge-bottom-space: env(safe-area-inset-bottom, 0px); }
  .challenge-intro { display: grid; gap: 3px; }
  .challenge-intro h2 { font-size: 1.15rem; line-height: 1.2; }
  .challenge-intro .label { font-size: .75rem; }
  .challenge-featured .challenge-board-preview { width: min(calc(100% - 12px), var(--challenge-board-size, calc(100svh - 360px))); justify-self: center; margin: 0 0 0 12px; }
  .challenge-action { gap: 6px; }
  .challenge-position-facts { font-size: .88rem; }
  .challenge-play-form { grid-template-columns: minmax(0, 1fr); gap: 6px; }
  .challenge-difficulty legend { margin-bottom: 3px; font-size: .875rem; }
  .challenges-page .challenge-play-form button, .challenges-page .challenge-start-tower { min-height: 44px; padding: 9px 12px; font-size: 1rem; }
  .challenge-meta { padding-top: 10px; border-top: 1px solid var(--border); }
  .challenge-grid { grid-template-columns: 1fr; }
  .challenge-grid .challenge-card { display: grid; grid-template-columns: minmax(100px, .7fr) 1fr; gap: 14px; align-items: start; }
  .challenge-grid .challenge-content { margin: 0; gap: 8px; }
  .challenge-grid h2 { font-size: 1.05rem; }
  .challenge-grid .challenge-link { padding: 10px; }
  .challenges-page .locale-nav { margin-left: 0; }
  .challenge-filters { padding: 12px; }
}