/* Public browser workspace, project previews and bounded motion. */
.no-js [data-motion-toggle], .no-js .concept-tabs, .no-js .preview-replay { display: none; }
.no-js .opening-choices { display: none; }
.motion-toggle { font: inherit; padding: 4px 2px; border: 0; background: none; color: inherit; cursor: pointer; text-decoration: underline; text-underline-offset: 3px; }
.motion-toggle:disabled { cursor: default; text-decoration: none; }
.motion-paused *, .motion-paused *::before, .motion-paused *::after { animation: none !important; transition: none !important; }
.board-arrows { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; z-index: 5; overflow: visible; }
.board-arrows path, .board-arrows circle { fill: none; stroke-width: .12; stroke-linecap: round; stroke-linejoin: round; }
.study-arrow { stroke: #d59220; opacity: .87; }
.analysis-arrow { stroke: #1c5f9d; opacity: .9; }
.sq:has(.piece) { overflow: visible; }
.sq .piece { position: relative; z-index: 2; }
.annotation-tools { justify-content: flex-start; }
.tbtn[aria-pressed="true"] { background: var(--brand); color: var(--on-brand); border-color: var(--brand); }
.eval-chip { background: var(--brand-soft); color: var(--brand-text); border-radius: 6px; padding: 4px 8px; font-variant-numeric: tabular-nums; min-width: 48px; text-align: center; }
[data-study] .moves { grid-template-columns: 44px 1fr; }
.analysis-status { font-size: .88rem; color: var(--ink-2); margin: 0; min-height: 2.8em; }
.analysis-lines { display: grid; gap: 6px; }
.analysis-line { text-align: left; display: grid; gap: 4px; padding: 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface-2); color: var(--ink); cursor: pointer; font: inherit; font-size: .88rem; }
.analysis-line strong { font-size: .82rem; }
.analysis-line span { overflow-wrap: anywhere; }
.analysis-line:hover { background: var(--brand-soft); border-color: var(--line-strong); }
.branch-options { display: flex; flex-wrap: wrap; gap: 6px; color: var(--ink-3); font-size: .84rem; padding-top: 7px; }
.solution-line { display: flex; gap: 6px; flex-wrap: wrap; }
.solution-line:empty { display: none; }
.solution-move { font-size: .86rem; background: var(--brand-soft); color: var(--brand-text); padding: 5px 8px; border-radius: 5px; font-weight: 600; }
.puzzle-filters { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.puzzle-filters .select { width: 100%; }
.games-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
.game-card { display: flex; flex-direction: column; gap: 16px; }
.game-card h3 { font-family: var(--serif); font-size: 1.7rem; font-weight: 400; margin: 0; }
.game-card p { font-size: .92rem; margin: 0; }
.game-card .link-arrow { margin-top: auto; }
.live-strip { border-bottom: 1px solid var(--line); }
.live-strip-grid { display: grid; grid-template-columns: repeat(4, 1fr); padding-block: 32px; gap: 24px; }
.live-strip-grid div { display: grid; gap: 6px; }
.live-strip strong { font: 400 2rem/1 var(--serif); }
.live-strip span { font-size: .84rem; color: var(--ink-2); }
.future-section, .future-page-hero { background: #142c27; color: #eff3e9; }
.future-section .section-head h2, .future-page-hero h1 { color: #faf6eb; }
.future-section h2 em, .future-page-hero h1 em { color: #d9bb83; }
.future-section .section-head p, .future-page-hero .lead { color: #d1ded3; }
.future-section .eyebrow, .future-page-hero .eyebrow { color: #d9bb83; }
.future-page-hero { padding-bottom: 70px; }
.future-page-hero h1 { max-width: 12ch; font-size: clamp(3.1rem, 6vw, 5.25rem); }
.future-feature { display: grid; grid-template-columns: 1fr 1fr; align-items: center; gap: clamp(24px, 5vw, 70px); padding: clamp(24px, 4vw, 48px); border: 1px solid #3a584b; border-radius: 20px; position: relative; overflow: hidden; }
.future-feature + .future-feature { margin-top: 24px; }
.ai-feature { background: linear-gradient(115deg, #1b392e, #244b3c); }
.engine-feature { background: linear-gradient(115deg, #18382f, #263e35); }
.future-copy { position: relative; z-index: 1; }
.future-copy h3 { font-family: var(--serif); font-weight: 400; font-size: clamp(2.4rem, 4.2vw, 3.8rem); color: #faf4e5; line-height: 1.03; letter-spacing: -.025em; margin: 26px 0 20px; }
.future-copy h3 em { color: #dbc18d; }
.future-copy p { color: #d8e3d8; max-width: 43ch; }
.btn-light { margin-top: 12px; background: #e6d8b8; color: #172a25; }
.btn-light:hover { color: #172a25; background: #faf0d6; }
.ai-concept { background: #f5f1e5; color: #172a25; border-radius: 16px; padding: clamp(20px, 3vw, 32px); box-shadow: 0 14px 50px rgba(0, 0, 0, .12); }
.ai-concept-light { border: 1px solid var(--line); background: #e7eddf; }
.concept-label { display: block; color: #52624f; font-size: .66rem; font-weight: 700; letter-spacing: .11em; line-height: 1.6; }
.concept-tabs { display: flex; gap: 6px; flex-wrap: wrap; margin: 22px 0; }
.concept-tabs button { min-height: 42px; padding: 9px 12px; border: 1px solid #bdc5b3; border-radius: 7px; background: transparent; color: #354a3b; font: inherit; font-size: .83rem; font-weight: 600; cursor: pointer; }
.concept-tabs button[aria-pressed="true"] { background: #214e40; color: #fff; border-color: #214e40; }
.concept-dialogue { min-height: 260px; display: flex; flex-direction: column; align-items: flex-start; }
.concept-question { align-self: flex-end; padding: 12px 14px; background: #e4ddc9; border-radius: 13px 13px 2px 13px; color: #3b432f; font-size: .88rem; max-width: 29ch; margin-bottom: 30px; }
.concept-dialogue h4 { color: #182e23; font: 400 1.65rem/1.1 var(--serif); margin-bottom: 10px; }
.concept-dialogue p { color: #40523e; font-size: .96rem; max-width: 38ch; }
.concept-footer { border-top: 1px solid #c6c9b9; padding-top: 14px; display: flex; gap: 10px; color: #52624f; font-size: .74rem; line-height: 1.5; }
.concept-footer > span:first-child { font-size: 1.2rem; color: #7d5e22; }
.opening-preview { background: #f5f1e5; padding: 16px; border-radius: 14px; color: #314333; max-width: 430px; width: 100%; justify-self: center; }
.opening-preview-light { border: 1px solid var(--line); }
.opening-preview .concept-label { margin-bottom: 12px; }
.opening-preview .board { box-shadow: none; }
.opening-preview .sq:disabled { cursor: default; }
.preview-foot { display: flex; gap: 14px; justify-content: space-between; align-items: center; padding-top: 12px; font-size: .76rem; min-height: 52px; }
.preview-foot > span { flex: 1; }
.preview-replay { border: 1px solid #b6bfae; border-radius: 5px; padding: 7px 9px; font: inherit; font-weight: 600; color: #33462e; background: transparent; cursor: pointer; }
.preview-replay:disabled { cursor: default; }
.future-goal h3 { font: 400 1.8rem/1.08 var(--serif); margin-top: 20px; }
.future-goal p { max-width: 33ch; }
@media (min-width: 1081px) { [data-study] .board-col, [data-trainer]:not([data-compact]) .board-col { position: sticky; top: 94px; } }
@media (max-width: 960px) { .future-feature { grid-template-columns: 1fr; } .future-copy p { max-width: 58ch; } .ai-concept { width: 100%; } .opening-preview { max-width: 480px; } .games-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 620px) { .live-strip-grid { grid-template-columns: 1fr 1fr; gap: 20px; } .future-feature { border-radius: 14px; } .games-grid { grid-template-columns: 1fr; } .concept-dialogue { min-height: 275px; } .preview-foot { flex-wrap: wrap; } .board-meta { gap: 7px; font-size: .79rem; } .eval-chip { font-size: .78rem; } .puzzle-filters { grid-template-columns: 1fr; } .pmeta { white-space: normal !important; text-align: right; } .motion-toggle { display: inline-block; } }

/* Puzzle-first homepage: one active task at a time, rather than a wall of demos. */
.reading-progress { position: fixed; top: 0; inset-inline: 0; height: 3px; z-index: 110; pointer-events: none; }
.reading-progress span { display: block; height: 100%; background: #a26a2c; transform: scaleX(0); transform-origin: left; }
.play-hero { padding-block: 50px 64px; }
.play-hero .hero-grid { grid-template-columns: 1fr 1fr; gap: clamp(28px, 6vw, 80px); }
.play-hero .hero-copy { padding-block: 14px; }
.play-hero h1 { font-size: clamp(3.7rem, 6.7vw, 6.4rem); margin-bottom: 2px; }
.hero-signature { display: block; width: min(90%, 320px); height: 28px; margin-bottom: 24px; overflow: visible; }
.hero-signature path { fill: none; stroke: #c9a86e; stroke-width: 2; stroke-linecap: round; }
.play-hero .lead { max-width: 34ch; margin-bottom: 24px; }
.play-hero .btn-primary { color: #172a25; background: #edddbd; border-color: #edddbd; }
.play-hero .btn-primary:hover { background: #fff3dc; }
.hero-proof { display: flex; gap: 16px; align-items: center; margin: 24px 0; color: #d8e3d8; }
.hero-proof strong { font: 400 3.2rem/1 var(--serif); color: #faf4e5; }
.hero-proof span { font-size: .85rem; line-height: 1.5; border-left: 1px solid #537365; padding-left: 16px; }
.hero-discover { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; font-size: .83rem; color: #d8e3d8; }
.hero-discover a { text-decoration: none; }
.hero-discover a:hover { color: #f6dfaf; text-decoration: underline; }
.hero-discover > span { color: #a8c0ae; }
.challenge-player { scroll-margin-top: 90px; }
.challenge-topline { display: flex; justify-content: space-between; gap: 12px; align-items: center; flex-wrap: wrap; margin-bottom: 12px; }
.challenge-progress { color: #52624f; font-size: .67rem; white-space: nowrap; }
.challenge-progress b { font-variant-numeric: tabular-nums; color: #214e40; }
.challenge-modes { display: grid; grid-template-columns: repeat(3, 1fr); background: #e9eddf; border-radius: 8px; padding: 4px; gap: 4px; margin-bottom: 14px; }
.challenge-modes button { min-width: 0; min-height: 40px; font: inherit; font-size: .78rem; font-weight: 600; border: 0; border-radius: 6px; background: transparent; color: #41583f; cursor: pointer; transition: background .18s, transform .18s; }
.challenge-modes button[aria-pressed="true"] { color: #fff; background: #214e40; box-shadow: 0 2px 5px #173a2514; }
.challenge-heading { display: flex; gap: 10px; align-items: center; justify-content: space-between; margin-bottom: 12px; }
.challenge-heading > div { display: grid; gap: 2px; min-width: 0; }
.challenge-heading strong { font-size: .87rem; line-height: 1.4; }
.challenge-heading [data-p-meta] { font-size: .72rem; }
.challenge-heading .select { font-size: .76rem; width: 116px; flex: 0 0 116px; padding: 8px; }
.challenge-player .trainer-feedback { min-height: 104px; font-size: .82rem; }
.challenge-player .trainer-feedback .fb-title { font-size: .88rem; }
.challenge-bottom { display: flex; align-items: center; justify-content: space-between; gap: 16px; border-top: 1px solid var(--line); margin-top: 14px; padding-top: 12px; color: #52624f; font-size: .68rem; }
.challenge-bottom > span { max-width: 29ch; }
.challenge-bottom a { white-space: nowrap; font-weight: 600; }
.experience-nav { background: #e7dfca; border-bottom: 1px solid #d8ceb5; }
.experience-nav .shell { display: grid; grid-template-columns: repeat(4, 1fr); }
.experience-nav a { min-height: 68px; display: flex; align-items: center; justify-content: center; gap: 14px; border-right: 1px solid #cfc6af; color: #304d41; text-decoration: none; font-size: .85rem; font-weight: 600; transition: background .18s; }
.experience-nav a:first-child { border-left: 1px solid #cfc6af; }
.experience-nav a:hover { background: #f0e8d4; }
.experience-nav span { color: #71592f; font-size: .65rem; }
.section-link { margin-top: 20px; }
.challenge-paths { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.challenge-path { position: relative; overflow: hidden; display: flex; flex-direction: column; min-height: 272px; border: 1px solid #c5d4bd; border-radius: 12px; background: #e6eddf; padding: 26px; text-decoration: none; color: #213d2e; transition: background .2s, border-color .2s, transform .2s; }
.challenge-path:nth-child(2n) { background: #eee5d3; border-color: #dacdb7; color: #493f2a; }
.challenge-path:hover { transform: translateY(-4px); color: #213d2e; border-color: #718f6d; background: #dce9d6; }
.challenge-path:active, .challenge-modes button:active, .tbtn:active:not(:disabled) { transform: scale(.98); }
.path-number { font-size: .65rem; font-weight: 700; letter-spacing: .13em; }
.challenge-path svg { position: absolute; width: 105px; height: 68px; right: 18px; top: 30px; color: currentColor; }
.challenge-path svg path, .challenge-path svg circle { fill: none; stroke: currentColor; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; transition: transform .35s; transform-origin: center; }
.challenge-path:hover svg path { transform: translate(2px, -3px); }
.challenge-path h3 { font: 400 clamp(1.8rem, 2.6vw, 2.5rem)/1.07 var(--serif); color: inherit; margin: 74px 0 22px; letter-spacing: -.025em; }
.path-foot { margin-top: auto; display: flex; justify-content: space-between; align-items: center; font-size: .82rem; font-weight: 600; }
.path-foot b { font-size: 1.2rem; transition: transform .2s; }
.challenge-path:hover .path-foot b { transform: translate(3px, -3px); }
.collection-note { font-size: .79rem; color: var(--ink-2); max-width: 90ch; margin: 24px 0 0; }
.master-experience { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(24px, 6vw, 70px); align-items: center; }
.master-board { min-width: 0; max-width: 520px; width: 100%; justify-self: center; }
.master-copy { display: flex; flex-direction: column; align-items: flex-start; gap: 16px; min-width: 0; }
.master-copy .select { width: 100%; max-width: 100%; }
.master-copy .field-label { margin-bottom: -10px; }
.master-copy h3 { font: 400 clamp(2rem, 3vw, 3rem)/1.08 var(--serif); letter-spacing: -.025em; margin: 10px 0 0; }
.master-copy p { color: var(--ink-2); margin: 0; }
.master-copy .master-players { font-weight: 600; font-size: .86rem; color: var(--brand-text); }
.master-position { font-size: .82rem; font-variant-numeric: tabular-nums; }
.master-moves { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; width: 100%; }
.master-moves button { font: inherit; font-size: .76rem; min-height: 38px; border: 1px solid var(--line-strong); border-radius: 5px; background: transparent; color: var(--ink); cursor: pointer; }
.master-moves button[aria-current="true"] { background: var(--brand); color: #fff; border-color: var(--brand); }
.future-copy h2 { font: 400 clamp(2.5rem, 4.2vw, 4rem)/1.04 var(--serif); color: #faf4e5; margin: 26px 0 20px; letter-spacing: -.025em; }
.future-copy h2 em { color: #dbc18d; }
.future-copy > .eyebrow { display: block; margin-bottom: 18px; }
.future-copy .future-disclosure { color: #d8e3d8; font-size: .8rem; line-height: 1.6; }
.ai-home-section { padding-top: 0; }
.opening-choices { display: flex; flex-wrap: wrap; gap: 5px; margin-bottom: 12px; }
.opening-choices button { background: transparent; color: #344b35; border: 1px solid #bdc5b3; font: inherit; font-size: .73rem; font-weight: 600; border-radius: 5px; min-height: 38px; padding: 6px 9px; cursor: pointer; }
.opening-choices button[aria-pressed="true"] { background: #214e40; border-color: #214e40; color: #fff; }
.home-closing { text-align: center; }
.home-closing p { max-width: 48ch; margin: 20px auto; color: var(--ink-2); }
.home-closing .link-arrow { display: inline-flex; margin-top: 24px; font-size: .85rem; }
.challenge-complete [data-board] { animation: solved-ring .65s ease-out 1; }
@keyframes solved-ring { 0%, 100% { box-shadow: 0 0 0 0 #39754d00; } 45% { box-shadow: 0 0 0 6px #39754d66; } }
@media (max-width: 960px) { .play-hero .hero-grid, .master-experience { grid-template-columns: 1fr; } .play-hero .hero-copy { max-width: 610px; } .play-hero h1 { font-size: clamp(3.8rem, 9vw, 5.4rem); } .play-hero .hero-visual { max-width: 520px; } .challenge-paths { grid-template-columns: 1fr 1fr; } .master-copy { max-width: 620px; } }
@media (max-width: 620px) { .play-hero { padding-block: 30px 40px; } .play-hero .hero-copy { padding: 0; } .play-hero h1 { font-size: clamp(3.15rem, 13vw, 4.5rem); } .play-hero .lead { font-size: .96rem; margin-bottom: 16px; } .hero-signature { width: 240px; height: 18px; margin-bottom: 14px; } .hero-proof { margin-block: 16px; } .hero-proof strong { font-size: 2.7rem; } .hero-discover { margin-top: 18px; } .play-hero .btn-row { flex-direction: row; align-items: center; gap: 6px 14px; } .play-hero .hero-text-link { font-size: .8rem; } .challenge-topline { gap: 4px; } .challenge-heading { flex-wrap: wrap; } .challenge-heading strong { font-size: .83rem; } .challenge-heading .select { width: 108px; flex-basis: 108px; } .challenge-modes button { font-size: .72rem; } .challenge-player .tbtn { padding-inline: 9px; font-size: .75rem; } .challenge-bottom { gap: 10px; font-size: .62rem; } .experience-nav .shell { grid-template-columns: 1fr 1fr; } .experience-nav a { min-height: 52px; border-bottom: 1px solid #cfc6af; justify-content: flex-start; padding-left: 14px; } .experience-nav a:nth-child(3) { border-left: 1px solid #cfc6af; } .challenge-path { min-height: 244px; padding: 18px; } .challenge-path svg { width: 72px; right: 8px; top: 38px; } .challenge-path h3 { font-size: 1.6rem; margin-top: 86px; } .path-number { font-size: .55rem; letter-spacing: .05em; } .path-foot { font-size: .72rem; gap: 5px; } .master-copy h3 { font-size: 2rem; } .master-moves { grid-template-columns: repeat(4, minmax(0, 1fr)); } .master-moves button { font-size: .69rem; } }
@media (max-width: 359px) { .challenge-paths { grid-template-columns: 1fr; } .challenge-path { min-height: 220px; } .challenge-path svg { width: 100px; top: 20px; } .challenge-path h3 { margin-top: 58px; } .challenge-player .hero-puzzle-foot { gap: 8px; } .challenge-progress { font-size: .62rem; } }