:root {
  --challenge-bg: #f4f5f7;
  --challenge-surface: #ffffff;
  --challenge-border: #dfe2e7;
  --challenge-text: #17191d;
  --challenge-muted: #707782;
  --challenge-yellow: #ffd13f;
  --challenge-yellow-dark: #e1ac00;
  --challenge-green: #16875f;
  --challenge-red: #c83d4b;
  --challenge-blue: #3369d6;
  --challenge-star: #e9a928;
  --challenge-star-highlight: #ffd96a;
  --challenge-star-shadow: #c98513;
  --challenge-radius-panel: 22px;
  --challenge-radius-card: 18px;
  --challenge-radius-control: 14px;
  --challenge-radius-compact: 10px;
  --challenge-radius-pill: 999px;
}

#ai-case-challenges.panel.active { display: block; min-width: 0; max-width: 100%; }
body:has(#ai-case-challenges.panel.active) .container { width: 1000px; max-width: 1000px; }
.challenge-page { box-sizing: border-box; width: 960px; max-width: 960px; margin: 0 auto; padding: 6px 4px 80px; color: var(--challenge-text); letter-spacing: 0; }
.challenge-header { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin-bottom: 26px; padding: 0; border: 0; }
.challenge-header h2 { margin: 0; font-size: 34px; line-height: 1.12; font-weight: 850; letter-spacing: 0; }
.challenge-header p { margin: 8px 0 0; color: var(--challenge-muted); font-size: 14px; line-height: 1.45; }
.challenge-header-actions, .challenge-detail-actions { display: flex; align-items: center; gap: 8px; }
.challenge-primary, .challenge-secondary, .challenge-danger, .challenge-detail-actions button, .challenge-admin-footer button, .challenge-empty button, .challenge-back, .challenge-discussion header button, .challenge-solution footer button {
  border: 1px solid var(--challenge-border); border-radius: 12px; background: var(--challenge-surface); color: var(--challenge-text); min-height: 38px; padding: 0 16px; font: inherit; font-size: 13px; font-weight: 700; cursor: pointer; transition: transform .18s ease, border-color .18s ease, background .18s ease, box-shadow .18s ease;
}
.challenge-primary, .challenge-detail-actions button.primary, .challenge-solution footer button.primary { background: linear-gradient(180deg, #ffe477, var(--challenge-yellow) 65%, #f0b900); border-color: var(--challenge-yellow-dark); color: #261f00; }
.challenge-danger, button.danger { color: var(--challenge-red) !important; border-color: rgba(200,61,75,.35) !important; }
.challenge-primary:hover, .challenge-secondary:hover, .challenge-danger:hover, .challenge-detail-actions button:hover, .challenge-admin-footer button:hover, .challenge-empty button:hover, .challenge-discussion header button:hover, .challenge-solution footer button:hover { transform: scale(1.025); }
.challenge-page button:disabled, .challenge-modal-layer button:disabled { cursor: default !important; opacity: .55; transform: none !important; }
.challenge-toolbar { display: grid; grid-template-columns: minmax(300px, 390px) minmax(0, 1fr); gap: 16px 18px; margin: 0 0 18px; padding: 18px; border: 1px solid var(--challenge-border); border-radius: 24px; background: var(--challenge-surface); box-shadow: 0 18px 50px rgba(15,23,42,.04); }
.challenge-page.is-detail > .challenge-header,
.challenge-page.is-detail > .challenge-toolbar { display: none; }
.challenge-toolbar-main { min-width: 0; display: flex; align-items: center; justify-content: flex-end; }
.challenge-toolbar-primary { display: flex; width: 100%; justify-content: flex-end; gap: 10px; align-items: center; }
.challenge-toolbar-primary .challenge-primary { min-width: 96px; min-height: 48px; padding: 0 20px; white-space: nowrap; }
.challenge-toolbar-filters { grid-column: 1 / -1; display: flex; align-items: center; gap: 10px; flex-wrap: wrap; padding-top: 14px; border-top: 1px solid var(--challenge-border); }
.challenge-search { display: flex; flex: 0 1 430px; align-items: center; gap: 8px; min-width: 240px; height: 48px; padding: 0 16px; border: 1px solid var(--challenge-border); border-radius: 16px; background: color-mix(in srgb, var(--challenge-surface) 94%, var(--challenge-bg)); }
.challenge-search span { font-size: 20px; color: var(--challenge-muted); }
.challenge-search input { width: 100%; min-width: 0; border: 0; outline: 0; background: transparent; color: inherit; font-size: 13px; }
.challenge-toolbar select { width: 130px; height: 38px; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-control); padding: 0 12px; background: var(--challenge-surface); color: inherit; }
.challenge-toolbar select:focus,
.challenge-toolbar select:focus-visible {
  outline: none;
  border-color: var(--challenge-border);
  box-shadow: none;
}
.challenge-segments { display: grid; grid-auto-flow: column; padding: 4px; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-pill); background: #e9ebef; }
.challenge-segments button { min-width: 62px; height: 32px; border: 0; border-radius: var(--challenge-radius-pill); background: transparent; color: var(--challenge-muted); cursor: pointer; }
.challenge-segments button.active { background: var(--challenge-surface); color: var(--challenge-text); box-shadow: 0 1px 3px rgba(22,24,28,.12); }

.challenge-layout { display: block; }
.challenge-layout > main { min-width: 0; }
.challenge-list-head { display: flex; align-items: baseline; justify-content: space-between; padding: 2px 0 11px; }
.challenge-list-head strong { font-size: 14px; }
.challenge-list-head span { color: var(--challenge-muted); font-size: 11px; }
.challenge-grid { display: grid; grid-template-columns: minmax(0,1fr); gap: 12px; }
.challenge-card { min-width: 0; overflow: hidden; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-card); background: var(--challenge-surface); cursor: pointer; transition: border-color .18s ease, box-shadow .18s ease, transform .18s ease; }
.challenge-card:hover { border-color: #bcc2cb; box-shadow: 0 8px 22px rgba(25,29,36,.08); transform: translateY(-1px); }
.challenge-compare-mini { position: relative; box-sizing: border-box; display: grid; grid-template-columns: repeat(3, minmax(0, 168px)); align-items: center; justify-content: center; gap: clamp(30px, 5vw, 56px); width: min(760px, 100%); min-width: 0; margin: 18px auto 0; padding: 18px 0; background: transparent; }
.challenge-compare-mini::before { content: ""; position: absolute; left: 18%; right: 18%; top: 50%; height: 1px; background: var(--challenge-border); }
.challenge-compare-mini figure { position: relative; z-index: 1; min-width: 0; aspect-ratio: 1; margin: 0; overflow: visible; border: 5px solid var(--challenge-bg); border-radius: var(--challenge-radius-control); background: #eef0f3; }
.challenge-compare-mini figure.failed { background: #f5ecee; }
.challenge-compare-mini figure.correct { background: #e8f3ee; }
.challenge-compare-mini img { width: 100%; max-width: 100%; height: 100%; aspect-ratio: 1; border-radius: inherit; object-fit: cover; display: block; }
.challenge-compare-mini figure > span { height: 100%; display: grid; place-items: center; color: var(--challenge-muted); font-size: 10px; }
.challenge-compare-mini figcaption { position: absolute; left: 7px; bottom: 7px; padding: 3px 7px; border-radius: var(--challenge-radius-pill); background: rgba(20,22,26,.72); color: white; font-size: 9px; }
.challenge-compare-mini > i { position: absolute; display: none; }
.challenge-compare-mini figure:nth-of-type(1)::after,
.challenge-compare-mini figure:nth-of-type(2)::after { content: "→"; position: absolute; left: calc(100% + clamp(12px, 2vw, 20px)); top: 50%; width: 18px; color: var(--challenge-muted); background: var(--challenge-surface); font-size: 17px; text-align: center; transform: translateY(-50%); }
.challenge-card-body { min-width: 0; padding: 22px 24px 15px; }
.challenge-card-top { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.challenge-status { display: inline-flex; align-items: center; height: 23px; padding: 0 9px; border-radius: var(--challenge-radius-pill); font-size: 10px; font-weight: 700; background: #edf0f3; color: #5d6570; }
.challenge-status.open { color: #9e3d48; background: #f9e8ea; }
.challenge-status.progress { color: #76580a; background: #fff4c7; }
.challenge-status.solved { color: #116d4c; background: #dff3e9; }
.challenge-difficulty { display: inline-flex; align-items: center; gap: 6px; white-space: nowrap; }
.challenge-difficulty > span { color: var(--challenge-star); font-size: 11px; letter-spacing: 0; text-shadow: 0 1px 0 rgba(255,255,255,.45); }
.challenge-difficulty small { color: var(--challenge-muted); font-size: 9px; }
.challenge-card h3 { margin: 12px 0 6px; font-size: 17px; line-height: 1.35; letter-spacing: 0; overflow-wrap: anywhere; }
.challenge-card p { margin: 0; color: #5d6570; font-size: 13px; line-height: 1.65; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.challenge-card-summary { display: grid; grid-template-columns: minmax(0,1.25fr) minmax(0,.75fr); gap: 24px; margin-top: 4px; padding-top: 16px; border-top: 1px solid var(--challenge-border); }
.challenge-card-prompt { display: grid; min-width: 0; gap: 6px; padding: 0; }
.challenge-card-prompt b { color: var(--challenge-text); font-size: 10px; }
.challenge-card-prompt span { display: -webkit-box; overflow: hidden; color: var(--challenge-muted); font-size: 11px; line-height: 1.6; -webkit-line-clamp: 4; -webkit-box-orient: vertical; }
.challenge-card-attempt { display: grid; min-width: 0; gap: 6px; padding: 0 0 0 24px; border-left: 1px solid var(--challenge-border); color: var(--challenge-muted); font-size: 10px; }
.challenge-card-attempt b { color: var(--challenge-text); font-size: 10px; }
.challenge-card-attempt span { display: -webkit-box; min-width: 0; overflow: hidden; line-height: 1.5; -webkit-line-clamp: 3; -webkit-box-orient: vertical; }
.challenge-card-meta { display: flex; gap: 9px; margin-top: 13px; padding-top: 11px; border-top: 1px solid var(--challenge-border); color: var(--challenge-muted); font-size: 10px; }
.challenge-card-meta time { margin-left: auto; }
.challenge-aside { min-width: 0; display: grid; grid-template-columns: 116px minmax(0,1fr); gap: 12px; padding-right: 18px; border-right: 1px solid var(--challenge-border); }
.challenge-my-stars { display: flex; min-width: 0; flex-direction: column; justify-content: center; padding: 12px; border: 1px solid #edc55b; border-radius: var(--challenge-radius-card); background: linear-gradient(145deg, #fffaf0, #fff4c9); }
.challenge-my-stars span, .challenge-my-stars small { display: block; color: #68540e; font-size: 10px; line-height: 1.35; }
.challenge-my-stars strong { display: block; margin: 3px 0; font-size: 27px; line-height: 1; color: var(--challenge-star-shadow); font-variant-numeric: tabular-nums; letter-spacing: 0; }
.challenge-my-stars strong::after { content: " ★"; color: var(--challenge-star); font-size: .62em; vertical-align: .16em; text-shadow: 0 1px 0 rgba(255,255,255,.55); }
.challenge-rank { min-width: 0; }
.challenge-rank h3 { margin: 0 0 8px; font-size: 12px; }
.challenge-rank ol { display: flex; gap: 7px; margin: 0; padding: 0 0 5px; overflow-x: auto; list-style: none; scrollbar-width: thin; }
.challenge-rank li { box-sizing: border-box; display: grid; flex: 0 0 168px; grid-template-columns: 20px minmax(0,1fr); align-items: center; gap: 6px; min-height: 54px; padding: 7px 8px; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-compact); background: color-mix(in srgb, var(--challenge-surface) 94%, var(--challenge-bg)); }
.challenge-rank li > b { color: var(--challenge-muted); font-size: 11px; font-variant-numeric: tabular-nums; }
.challenge-rank li span { min-width: 0; }
.challenge-rank li strong, .challenge-rank li small { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.challenge-rank li strong { font-size: 11px; }.challenge-rank li small { color: var(--challenge-muted); font-size: 9px; margin-top: 2px; }
.challenge-rank li em { grid-column: 2; color: var(--challenge-star-shadow); font-size: 10px; font-style: normal; font-weight: 750; text-shadow: 0 1px 0 rgba(255,255,255,.4); }
.challenge-rank li.empty { display: block; flex-basis: 100%; padding: 12px; color: var(--challenge-muted); font-size: 11px; }

.challenge-loading, .challenge-empty { min-height: 300px; display: grid; place-items: center; align-content: center; gap: 8px; color: var(--challenge-muted); }
.challenge-empty strong { color: var(--challenge-text); font-size: 16px; }.challenge-empty span { font-size: 12px; }
.challenge-detail { min-width: 0; opacity: 1; transform: translateY(0); transition: opacity .24s ease, transform .28s cubic-bezier(.22,1,.36,1); }
.challenge-detail.is-entering { opacity: 0; transform: translateY(18px); }
.challenge-detail.is-entered { opacity: 1; transform: translateY(0); }
.challenge-back { margin-bottom: 12px; border: 0; padding: 0; background: transparent; color: var(--challenge-muted); }
.challenge-detail-head { display: flex; justify-content: space-between; gap: 20px; padding: 18px 0; border-top: 1px solid var(--challenge-border); border-bottom: 1px solid var(--challenge-border); }
.challenge-detail-head h2 { margin: 9px 0 6px; font-size: 23px; line-height: 1.25; letter-spacing: 0; }
.challenge-detail-head p { margin: 0; color: var(--challenge-muted); font-size: 11px; }
.challenge-detail-badges { display: flex; gap: 8px; align-items: center; }
.challenge-detail-actions .challenge-banana-import { position: relative; display: grid; width: 44px; min-width: 44px; height: 44px; min-height: 44px; place-items: center; padding: 5px; border-color: var(--challenge-border); border-radius: 12px; background: color-mix(in srgb, var(--challenge-surface) 91%, var(--challenge-yellow)); }
.challenge-banana-import img { display: block; width: 32px; height: 32px; object-fit: contain; }
.challenge-banana-import [role="tooltip"] { position: absolute; z-index: 5; left: 50%; bottom: calc(100% + 10px); width: max-content; max-width: 180px; padding: 7px 10px; border-radius: 8px; background: #24272c; color: #fff; box-shadow: 0 8px 24px rgba(15,17,20,.2); font-size: 11px; font-weight: 600; line-height: 1.35; white-space: nowrap; opacity: 0; pointer-events: none; transform: translate(-50%, 5px) scale(.96); transform-origin: 50% 100%; transition: opacity .15s ease, transform .15s ease; }
.challenge-banana-import [role="tooltip"]::after { content: ""; position: absolute; left: 50%; top: 100%; border: 5px solid transparent; border-top-color: #24272c; transform: translateX(-50%); }
.challenge-banana-import:hover [role="tooltip"],
.challenge-banana-import:focus-visible [role="tooltip"] { opacity: 1; transform: translate(-50%, 0) scale(1); }
.challenge-problem { padding: 20px 0 14px; }.challenge-problem h3, .challenge-detail-columns h3, .challenge-compare-track h3, .challenge-community-difficulty h3, .challenge-solutions-head h3, .challenge-discussion h3, .challenge-attachments h3 { margin: 0 0 8px; font-size: 13px; }
.challenge-problem p, .challenge-detail-columns p { margin: 0; font-size: 13px; line-height: 1.7; white-space: pre-wrap; overflow-wrap: anywhere; }
.challenge-compare-track { display: grid; grid-template-columns: minmax(0,1fr) 24px minmax(0,1fr) 24px minmax(0,1fr) 24px minmax(0,1fr); align-items: center; padding: 16px; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-card); background: #f7f8f9; }
.challenge-compare-track > i { color: var(--challenge-muted); font-style: normal; text-align: center; }
.challenge-compare-track > div { min-width: 0; }.challenge-compare-track .failed h3 { color: var(--challenge-red); }.challenge-compare-track .resolved h3 { color: var(--challenge-green); }
.challenge-image-strip { display: grid; grid-template-columns: repeat(auto-fit,minmax(72px,1fr)); gap: 5px; min-height: 105px; }
.challenge-image-strip button { min-width: 0; height: 105px; padding: 0; overflow: hidden; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-compact); background: white; cursor: zoom-in; }
.challenge-image-strip img { width: 100%; height: 100%; object-fit: cover; display: block; }
.challenge-image-empty { height: 105px; display: grid; place-items: center; border: 1px dashed #cbd0d7; border-radius: var(--challenge-radius-compact); color: var(--challenge-muted); font-size: 11px; }
.challenge-detail-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; padding: 14px 0; }
.challenge-detail-columns > section { min-width: 0; padding: 14px; border: 1px solid var(--challenge-border); border-left: 3px solid #b9c0ca; border-radius: var(--challenge-radius-control); background: #f7f8f9; }
.challenge-detail-columns pre, .challenge-solution pre { margin: 0; white-space: pre-wrap; overflow-wrap: anywhere; font: inherit; font-size: 12px; line-height: 1.65; }
.challenge-attachments { display: grid; grid-template-columns: minmax(260px,.7fr) minmax(0,1.3fr); gap: 12px; padding: 0 0 14px; }.challenge-attachments > div { min-width: 0; }.challenge-attachments h3 small { margin-left: 5px; color: var(--challenge-muted); font-size: 10px; font-weight: 500; }.challenge-presentation-card { box-sizing: border-box; display: grid; width: 100%; grid-template-columns: 44px minmax(0,1fr) auto; align-items: center; gap: 11px; min-height: 68px; padding: 10px 12px; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-control); background: var(--challenge-surface); color: inherit; font: inherit; text-align: left; cursor: pointer; transition: border-color .16s ease, background .16s ease, transform .16s ease; }.challenge-presentation-card:hover { border-color: #c69212; background: #fff9df; transform: scale(1.005); }.challenge-presentation-card:focus-visible { outline: 2px solid rgba(198,146,18,.34); outline-offset: 2px; }.challenge-presentation-card strong, .challenge-presentation-card small { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }.challenge-presentation-card strong { font-size: 12px; }.challenge-presentation-card small { margin-top: 4px; color: var(--challenge-muted); font-size: 10px; }.challenge-presentation-card > b { color: #8b680b; font-size: 11px; }.challenge-attachment-empty { display: grid; min-height: 68px; place-items: center; border: 1px dashed var(--challenge-border); border-radius: var(--challenge-radius-control); color: var(--challenge-muted); font-size: 11px; }
.challenge-community-difficulty { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 13px 0; border-top: 1px solid var(--challenge-border); border-bottom: 1px solid var(--challenge-border); }
.challenge-vote-count, .challenge-vote-empty { margin-left: 7px; color: var(--challenge-muted); font-size: 10px; }.challenge-vote-buttons { display: flex; gap: 5px; }
.challenge-vote-buttons button { min-width: 38px; height: 30px; padding: 0 7px; border: 1px solid var(--challenge-border); border-radius: 12px; background: var(--challenge-surface); color: var(--challenge-star); font-size: 10px; font-weight: 700; cursor: pointer; text-shadow: 0 1px 0 rgba(255,255,255,.45); }
.challenge-solutions-head { display: flex; align-items: center; justify-content: space-between; padding: 18px 0 10px; }.challenge-solutions-head > div { display: flex; align-items: baseline; gap: 8px; }.challenge-solutions-head span { color: var(--challenge-muted); font-size: 10px; }
.challenge-solutions { display: grid; gap: 10px; }.challenge-solution { padding: 16px; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-card); background: var(--challenge-surface); }.challenge-solution.accepted { border-color: var(--challenge-yellow-dark); box-shadow: inset 4px 0 0 var(--challenge-yellow); }
.challenge-solution > header { display: flex; justify-content: space-between; align-items: center; }.challenge-solution > header span { font-size: 12px; font-weight: 700; }.challenge-solution > header time { margin-left: 8px; color: var(--challenge-muted); font-size: 10px; }.challenge-solution > header > strong { color: #7c5e00; font-size: 11px; }
.challenge-solution-images { margin: 12px 0; }.challenge-solution section { padding: 11px 0; border-top: 1px solid var(--challenge-border); }.challenge-solution h4 { margin: 0 0 7px; font-size: 11px; color: var(--challenge-muted); }.challenge-solution section p { margin: 0; font-size: 12px; line-height: 1.65; white-space: pre-wrap; }
.challenge-solution footer { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding-top: 12px; border-top: 1px solid var(--challenge-border); }.challenge-solution footer > span { color: var(--challenge-muted); font-size: 10px; }.challenge-solution footer > div { display: flex; gap: 6px; }.challenge-solution footer button { min-height: 31px; padding: 0 9px; font-size: 10px; }
.challenge-solution-empty { padding: 35px; border: 1px dashed var(--challenge-border); border-radius: var(--challenge-radius-card); text-align: center; color: var(--challenge-muted); font-size: 12px; }
.challenge-discussion { margin-top: 18px; padding-top: 14px; border-top: 1px solid var(--challenge-border); }.challenge-discussion > header { display: flex; align-items: center; justify-content: space-between; }.challenge-discussion header > div { display: flex; gap: 8px; align-items: baseline; }.challenge-discussion header span { color: var(--challenge-muted); font-size: 10px; }.challenge-discussion ul { margin: 8px 0 0; padding: 0; list-style: none; }.challenge-discussion li { display: grid; grid-template-columns: 95px minmax(0,1fr) 70px; gap: 12px; padding: 10px 0; border-top: 1px solid var(--challenge-border); font-size: 11px; }.challenge-discussion li b { overflow: hidden; text-overflow: ellipsis; }.challenge-discussion li p { margin: 0; line-height: 1.55; white-space: pre-wrap; }.challenge-discussion li time { text-align: right; color: var(--challenge-muted); }.challenge-discussion li.empty { display: block; color: var(--challenge-muted); }
.challenge-admin-footer { display: flex; justify-content: flex-end; gap: 7px; padding-top: 14px; }

.challenge-modal-layer { position: fixed; inset: 0; z-index: 10050; display: grid; place-items: center; padding: 20px; }.challenge-modal-layer[hidden] { display: none; }.challenge-modal-scrim { position: absolute; inset: 0; background: rgba(15,17,20,.5); backdrop-filter: blur(3px); }.challenge-modal { position: relative; width: min(760px,100%); max-height: min(880px,94vh); overflow: auto; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-panel); background: var(--challenge-surface); box-shadow: 0 22px 70px rgba(0,0,0,.25); padding: 22px; }.challenge-modal > header { padding-right: 24px; margin-bottom: 17px; }.challenge-modal > header h2 { margin: 0; font-size: 19px; letter-spacing: 0; }.challenge-modal > header p { margin: 5px 0 0; color: var(--challenge-muted); font-size: 11px; }
.challenge-modal { box-sizing: border-box; }
.challenge-presentation-modal { width: min(980px, 100%); height: min(820px, 94vh); overflow: hidden; }
.challenge-presentation-viewer { min-height: 0; height: calc(100% - 58px); overflow: hidden; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-control); background: #eef0f3; }
.challenge-presentation-viewer iframe { display: block; width: 100%; height: 100%; border: 0; background: #fff; }
.challenge-modal-wide { width: min(1180px, 100%); max-height: calc(100vh - 40px); overflow: hidden; }
.challenge-form { display: grid; gap: 13px; }
.challenge-form-meta,
.challenge-form-visual-flow,
.challenge-form-details,
.challenge-form-attachments { min-width: 0; display: grid; gap: 12px; }
.challenge-form-visual-flow > *,
.challenge-form-details > *,
.challenge-form-attachments > * { min-width: 0; }
.challenge-form label > span,
.challenge-file-picker header > span,
.challenge-difficulty-picker legend { display: block; margin-bottom: 6px; font-size: 11px; font-weight: 650; }
.challenge-form b { color: var(--challenge-red); font-size: 9px; }
.challenge-form input:not([type=radio]):not([type=file]),
.challenge-form textarea { box-sizing: border-box; width: 100%; border: 1px solid var(--challenge-border); border-radius: var(--challenge-radius-control); padding: 10px 12px; background: var(--challenge-surface); color: inherit; font: inherit; font-size: 12px; line-height: 1.5; resize: vertical; }
.challenge-form input:focus,
.challenge-form textarea:focus { outline: 2px solid rgba(51,105,214,.22); border-color: var(--challenge-blue); }
.challenge-form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 11px; }
.challenge-form-files { display: grid; grid-template-columns: 1fr 1fr; gap: 11px; align-items: start; }
.challenge-file-picker { min-width: 0; padding: 12px; border: 1px dashed #bbc1ca; border-radius: var(--challenge-radius-control); transition: border-color .16s ease, background .16s ease; }
.challenge-file-picker > input { position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none; }
.challenge-file-picker > header { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; }
.challenge-file-picker header > span { margin-bottom: 8px; }
.challenge-file-picker header > small { color: var(--challenge-muted); font-size: 9px; font-variant-numeric: tabular-nums; }
.challenge-upload-grid { display: grid; gap: 8px; outline: none; }
.challenge-file-picker[data-max="6"] .challenge-upload-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.challenge-file-picker[data-max="2"] .challenge-upload-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.challenge-file-picker[data-max="1"] .challenge-upload-grid { grid-template-columns: minmax(0, 1fr); justify-content: center; }
.challenge-form-create .challenge-file-picker[data-max="1"] .challenge-upload-grid { grid-template-columns: minmax(0, 1fr); }
.challenge-form-create .challenge-file-picker[data-max="1"] .challenge-upload-slot { max-width: none; }
.challenge-file-picker.is-compact { padding: 9px 12px; }.challenge-file-picker.is-compact .challenge-upload-grid { grid-auto-flow: column; grid-auto-columns: 68px; grid-template-columns: none; align-content: start; justify-content: start; overflow-x: auto; overflow-y: hidden; padding: 2px 2px 5px; scrollbar-width: thin; }.challenge-file-picker.is-compact .challenge-upload-slot { width: 68px; }.challenge-file-picker.is-compact header > span { margin-bottom: 5px; }
.challenge-upload-slot { position: relative; display: grid; width: 100%; min-width: 0; aspect-ratio: 1; place-items: center; padding: 0; border: 1px dashed var(--challenge-border); border-radius: 12px; background: #f4f5f7; color: var(--challenge-muted); cursor: pointer; transition: border-color .16s ease, background .16s ease, transform .16s ease; }
.challenge-upload-slot:hover { border-color: #b58a12; background: #fff9df; transform: scale(1.015); }
.challenge-upload-slot:focus-visible { outline: 2px solid rgba(198,146,18,.34); outline-offset: 2px; }
.challenge-upload-slot.is-filled { border-style: solid; background: #eceff2; }
.challenge-upload-slot > img { width: 100%; height: 100%; border-radius: 11px; object-fit: cover; display: block; }
.challenge-upload-remove { position: absolute; top: 5px; right: 5px; z-index: 2; display: grid; width: 24px; height: 24px; place-items: center; padding: 0 0 2px; border: 0; border-radius: 999px; background: rgba(0,0,0,.64); color: #fff; font: 500 20px/1 system-ui,sans-serif; cursor: pointer; transition: background-color .16s ease, transform .16s ease; }
.challenge-upload-remove:hover { background: rgba(0,0,0,.78); transform: scale(1.06); }
.challenge-upload-remove:active { transform: scale(.96); }
.challenge-upload-remove:focus-visible { outline: 2px solid rgba(255,255,255,.92); outline-offset: 2px; }
.challenge-upload-annotate { position: absolute; left: 8px; bottom: 8px; z-index: 2; min-height: 27px; padding: 0 10px; border: 1px solid rgba(255,255,255,.76); border-radius: 9px; background: rgba(24,27,31,.72); backdrop-filter: blur(8px); color: #fff; font-size: 10px; font-weight: 650; cursor: pointer; transition: transform 140ms cubic-bezier(.23,1,.32,1), background-color 140ms ease; }.challenge-upload-annotate:hover { background: rgba(24,27,31,.88); transform: scale(1.04); }.challenge-upload-annotate:active { transform: scale(.97); }.challenge-upload-annotate:focus-visible { outline: 2px solid #ffd13f; outline-offset: 2px; }
.challenge-upload-plus { position: relative; width: 22px; height: 22px; opacity: .72; }
.challenge-upload-plus::before,
.challenge-upload-plus::after { content: ""; position: absolute; left: 50%; top: 50%; width: 16px; height: 2px; border-radius: 2px; background: currentColor; transform: translate(-50%,-50%); }
.challenge-upload-plus::after { transform: translate(-50%,-50%) rotate(90deg); }
.challenge-file-picker.is-dragging,
.challenge-file-picker.is-paste-target { border-color: #c69212; background: #fff9df; }
.challenge-file-picker.is-dragging .challenge-upload-slot { border-color: #c69212; background: #fff4c5; }
.challenge-presentation-picker { min-width: 0; padding: 9px 12px; border: 1px dashed #bbc1ca; border-radius: var(--challenge-radius-control); transition: border-color .16s ease, background .16s ease; }.challenge-presentation-picker > header { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; }.challenge-presentation-picker > header span { font-size: 11px; font-weight: 650; }.challenge-presentation-picker > header small { color: var(--challenge-muted); font-size: 9px; }.challenge-presentation-picker > input { position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none; }.challenge-presentation-select { box-sizing: border-box; display: grid; width: 100%; min-height: 58px; grid-template-columns: 38px minmax(0,1fr) auto; align-items: center; gap: 10px; margin-top: 5px; padding: 6px 10px; border: 1px solid var(--challenge-border); border-radius: 12px; background: #f4f5f7; color: inherit; text-align: left; cursor: pointer; transition: border-color .16s ease, background .16s ease, transform .16s ease; }.challenge-presentation-select:hover { border-color: #b58a12; background: #fff9df; transform: scale(1.005); }.challenge-presentation-select:focus-visible { outline: 2px solid rgba(198,146,18,.34); outline-offset: 2px; }.challenge-presentation-icon { display: grid; width: 36px; height: 36px; place-items: center; border-radius: 9px; background: #e64b3c; color: #fff; font-size: 9px; font-weight: 800; }.challenge-presentation-copy { min-width: 0; }.challenge-presentation-copy strong, .challenge-presentation-copy small { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }.challenge-presentation-copy strong { font-size: 12px; }.challenge-presentation-copy small { margin-top: 3px; color: var(--challenge-muted); font-size: 9px; }.challenge-presentation-action { color: #896708; font-size: 10px; font-weight: 700; }.challenge-presentation-picker.has-file, .challenge-presentation-picker.is-dragging { border-color: #c69212; background: #fff9df; }
.challenge-difficulty-picker { margin: 0; padding: 0; border: 0; }.challenge-difficulty-picker { display: grid; grid-template-columns: repeat(5,1fr); gap: 5px; }.challenge-difficulty-picker legend { grid-column: 1/-1; }.challenge-difficulty-picker label { min-width: 0; }.challenge-difficulty-picker input { position: absolute; opacity: 0; }.challenge-difficulty-picker label > span { height: 44px; display: grid; place-items: center; align-content: center; margin: 0; border: 1px solid var(--challenge-border); border-radius: 12px; color: var(--challenge-star); cursor: pointer; font-size: 10px; text-shadow: 0 1px 0 rgba(255,255,255,.45); }.challenge-difficulty-picker small { display: block; color: var(--challenge-muted); font-size: 8px; margin-top: 2px; text-shadow: none; }.challenge-difficulty-picker input:checked + span { border-color: #e0ad32; background: linear-gradient(145deg, #fffdf4, #fff2bf); }
.challenge-form footer { display: flex; justify-content: flex-end; align-items: center; gap: 12px; min-height: 40px; padding-top: 5px; }.challenge-form footer > span { margin-right: auto; color: var(--challenge-red); font-size: 11px; }
.challenge-form footer [data-save-challenge-draft] { min-width: 88px; }
.challenge-image-preview { height: min(760px,82vh); display: grid; place-items: center; background: #f0f1f3; }.challenge-image-preview img { max-width: 100%; max-height: 100%; object-fit: contain; }
.image-challenge-toast { position: fixed; z-index: 11000; left: 50%; bottom: 28px; transform: translate(-50%,16px); opacity: 0; pointer-events: none; padding: 10px 15px; border-radius: var(--challenge-radius-control); background: #1c1f24; color: white; font-size: 12px; transition: opacity .18s ease, transform .18s ease; }.image-challenge-toast.show { opacity: 1; transform: translate(-50%,0); }.image-challenge-toast.error { background: #9f2935; }

html.theme-dark .challenge-page,
html.theme-dark .challenge-modal-layer {
  --challenge-bg: #181a1e;
  --challenge-surface: #22252a;
  --challenge-border: #3a3e45;
  --challenge-text: #f2f3f5;
  --challenge-muted: #a1a7b0;
  --challenge-star: #ffd45a;
  --challenge-star-highlight: #ffeaa3;
  --challenge-star-shadow: #e3af2f;
  color: var(--challenge-text);
  color-scheme: dark;
}
html.theme-dark .challenge-toolbar,
html.theme-dark .challenge-modal,
html.theme-dark .challenge-card,
html.theme-dark .challenge-solution { background: var(--challenge-surface); }
html.theme-dark .challenge-segments { background: #2d3036; }
html.theme-dark .challenge-card p { color: #b8bdc5; }
html.theme-dark .challenge-card-attempt b { background: transparent; }
html.theme-dark .challenge-compare-mini { background: transparent; }
html.theme-dark .challenge-status { color: #c2c7cf; background: #30343a; }
html.theme-dark .challenge-status.open { color: #ffabb4; background: #482b31; }
html.theme-dark .challenge-status.progress { color: #f4d779; background: #433a1e; }
html.theme-dark .challenge-status.solved { color: #8eddbf; background: #203d34; }
html.theme-dark .challenge-my-stars { background: #3b3214; border-color: #806811; }
.theme-dark .challenge-my-stars span,
.theme-dark .challenge-my-stars small { color: #dccb83; }
.theme-dark .challenge-my-stars strong { color: var(--challenge-star-highlight); }
html.theme-dark .challenge-rank li { background: #1d2024; }
html.theme-dark .challenge-detail-actions .challenge-banana-import { border-color: #545960; background: #2b2e33; }
html.theme-dark .challenge-compare-track,
html.theme-dark .challenge-detail-columns > section { background: #202328; }
.theme-dark .challenge-compare-mini figure { background: #282c32; }
html.theme-dark .challenge-compare-mini figure.failed { background: #34272b; }
html.theme-dark .challenge-compare-mini figure.correct { background: #203d34; }
html.theme-dark .challenge-image-strip button { background: #202328; }
html.theme-dark .challenge-image-empty,
html.theme-dark .challenge-file-picker,
html.theme-dark .challenge-presentation-picker,
html.theme-dark .challenge-attachment-empty { border-color: #535861; }
html.theme-dark .challenge-upload-slot { background: #1d2024; }
html.theme-dark .challenge-upload-slot:hover { border-color: #b98b1e; background: #332d19; }
html.theme-dark .challenge-upload-slot.is-filled { background: #292d32; }
html.theme-dark .challenge-presentation-select { background: #1d2024; }
html.theme-dark .challenge-presentation-viewer { background: #17191d; }
html.theme-dark .challenge-presentation-select:hover,
html.theme-dark .challenge-presentation-card:hover { border-color: #b98b1e; background: #332d19; }
html.theme-dark .challenge-presentation-picker.has-file,
html.theme-dark .challenge-presentation-picker.is-dragging { border-color: #b98b1e; background: #2f2918; }
html.theme-dark .challenge-file-picker.is-dragging,
html.theme-dark .challenge-file-picker.is-paste-target { border-color: #b98b1e; background: #2f2918; }
html.theme-dark .challenge-file-picker.is-dragging .challenge-upload-slot { border-color: #b98b1e; background: #3a321a; }
html.theme-dark .challenge-difficulty-picker input:checked + span { border-color: #b98b1e; background: #403617; }
html.theme-dark .challenge-form input:not([type=radio]):not([type=file]),
html.theme-dark .challenge-form textarea { background: #1d2024; }
html.theme-dark .challenge-image-preview { background: #17191d; }
html.theme-dark .challenge-modal-scrim { background: rgba(0,0,0,.72); }

@media (max-width: 1040px) { body:has(#ai-case-challenges.panel.active) .container { width: 100%; max-width: 100%; } }
@media (max-width: 1040px) { .challenge-toolbar { grid-template-columns: minmax(0,1fr); }.challenge-toolbar-main { order: 1; }.challenge-aside { order: 2; padding: 14px 0 0; border-top: 1px solid var(--challenge-border); border-right: 0; }.challenge-toolbar-filters { order: 3; } }
@media (min-width: 901px) {
  .challenge-form-wide { gap: 12px; }
  .challenge-form-meta { grid-template-columns: minmax(260px, 1.15fr) minmax(160px, .65fr) minmax(480px, 1.6fr); align-items: end; }
  .challenge-form-meta-solution { grid-template-columns: repeat(2, minmax(0, 240px)); }
  .challenge-form-visual-flow { grid-template-columns: minmax(280px, .9fr) minmax(320px, 1.15fr) minmax(280px, .9fr); align-items: stretch; }
  .challenge-form-create .challenge-form-visual-flow { grid-template-columns: minmax(190px,.55fr) minmax(380px,1.35fr) minmax(210px,.72fr) minmax(210px,.72fr); }
  .challenge-form-create [data-challenge-file-picker="referenceFiles"] .challenge-upload-grid { grid-template-columns: repeat(2, 72px); justify-content: center; }
  .challenge-form-create .challenge-file-picker[data-challenge-file-picker="failedFiles"] .challenge-upload-grid,
  .challenge-form-create .challenge-file-picker[data-challenge-file-picker="correctFiles"] .challenge-upload-grid { grid-template-columns: minmax(0, 180px); justify-content: center; }
  .challenge-form-create .challenge-file-picker[data-challenge-file-picker="failedFiles"] .challenge-upload-slot,
  .challenge-form-create .challenge-file-picker[data-challenge-file-picker="correctFiles"] .challenge-upload-slot { max-width: 180px; }
  .challenge-form-details { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .challenge-form-attachments { grid-template-columns: minmax(320px,.75fr) minmax(0,1.25fr); align-items: stretch; }
  .challenge-form-details-single { grid-template-columns: minmax(0, 1fr); }
  .challenge-prompt-field { display: flex; min-height: 0; flex-direction: column; }
  .challenge-prompt-field textarea { flex: 1 1 auto; min-height: 0; }
  .challenge-form-wide textarea { resize: none; }
  .challenge-form-visual-flow .challenge-file-picker { display: grid; grid-template-rows: auto 1fr; }
  .challenge-form-visual-flow .challenge-upload-grid { align-content: center; }
  .challenge-form-create .challenge-form-visual-flow { min-height: 250px; }
  .challenge-form-solution .challenge-form-visual-flow { min-height: 248px; }
  .challenge-form-details textarea { height: 82px; }
}
@media (min-width: 901px) and (max-height: 720px) {
  .challenge-modal-wide { max-height: calc(100vh - 24px); padding: 18px; }
  .challenge-modal-wide > header { margin-bottom: 12px; }
  .challenge-form-wide { gap: 8px; }
  .challenge-form-create .challenge-form-visual-flow,
  .challenge-form-solution .challenge-form-visual-flow { min-height: 232px; }
  .challenge-form-details textarea { height: 72px; }
  .challenge-form-create .challenge-form-visual-flow { min-height: 240px; }
}
@media (max-width: 900px) { .challenge-page { width: 100%; max-width: 100%; }.challenge-modal-wide { width: min(760px,100%); max-height: min(880px,94vh); overflow: auto; }.challenge-presentation-modal { width: min(760px,100%); height: 94vh; }.challenge-toolbar-filters { display: grid; grid-template-columns: 1fr 1fr; }.challenge-segments { grid-column: 1/-1; }.challenge-toolbar select { width: 100%; }.challenge-grid { grid-template-columns: 1fr; }.challenge-compare-track { grid-template-columns: 1fr; gap: 7px; }.challenge-compare-track > i { transform: rotate(90deg); }.challenge-detail-columns, .challenge-attachments, .challenge-form-attachments { grid-template-columns: 1fr; } }
@media (max-width: 620px) { .challenge-file-picker[data-max="1"] .challenge-upload-grid { grid-template-columns: minmax(0, 190px); }.challenge-form footer { gap: 7px; }.challenge-form footer [data-save-challenge-draft], .challenge-form footer .challenge-primary { min-width: 0; padding-left: 11px; padding-right: 11px; } }
@media (max-width: 620px) { .challenge-page { padding: 6px 12px 60px; }.challenge-header > div:first-child { min-width: 0; }.challenge-header h2 { font-size: 28px; }.challenge-header p { display: none; }.challenge-toolbar { padding: 14px; }.challenge-toolbar-primary { display: grid; grid-template-columns: 1fr; }.challenge-search { width: auto; min-width: 0; }.challenge-toolbar-primary .challenge-primary { width: 100%; }.challenge-toolbar-filters { grid-template-columns: 1fr; }.challenge-segments { grid-column: auto; overflow-x: auto; }.challenge-toolbar select { width: 100%; }.challenge-list-head span { display: none; }.challenge-card { width: 100%; min-width: 0; }.challenge-card-body { padding: 16px 14px 13px; }.challenge-compare-mini { height: auto; padding: 12px 0; gap: 18px; }.challenge-compare-mini figure { border-width: 3px; }.challenge-compare-mini figure:nth-of-type(1)::after, .challenge-compare-mini figure:nth-of-type(2)::after { left: calc(100% + 3px); font-size: 13px; }.challenge-card-summary { grid-template-columns: 1fr; gap: 12px; }.challenge-card-attempt { padding: 12px 0 0; border-top: 1px solid var(--challenge-border); border-left: 0; }.challenge-aside { grid-template-columns: 100px minmax(0,1fr); }.challenge-rank li { flex-basis: 152px; }.challenge-detail-head { display: grid; }.challenge-detail-actions { justify-content: flex-end; }.challenge-community-difficulty, .challenge-solution footer { align-items: flex-start; flex-direction: column; }.challenge-solution footer > div { width: 100%; overflow-x: auto; }.challenge-discussion li { grid-template-columns: 75px minmax(0,1fr); }.challenge-discussion li time { display: none; }.challenge-modal-layer { padding: 8px; }.challenge-modal { padding: 17px; }.challenge-form-row, .challenge-form-files { grid-template-columns: 1fr; }.challenge-difficulty-picker { grid-template-columns: repeat(3,1fr); }.challenge-difficulty-picker legend { grid-column: 1/-1; } }
@media (prefers-reduced-motion: reduce) { .challenge-card, .challenge-detail, .challenge-primary, .challenge-secondary, .challenge-danger, .image-challenge-toast { transition: none; } }