.bt-app{--bt-accent:var(--brand-accent,#e55d2e);--bt-text:var(--brand-ink,#1f2326);--bt-muted:var(--brand-muted,#686a67);--bt-border:var(--brand-border,#d9d0c6);background:var(--brand-paper,#f6f1e8);min-height:100vh;color:var(--bt-text)}.bt-app button{cursor:pointer}.bt-app button:disabled{opacity:.38;cursor:not-allowed}.bt-app ::selection{background:var(--brand-accent-deep,#b84422);color:#fff}.bt-shell{max-width:1510px;margin:0 auto;padding:clamp(20px,3vw,48px)}.bt-heading{justify-content:space-between;align-items:flex-end;gap:32px;margin:10px 0 28px;display:flex}.bt-heading h1{letter-spacing:-.065em;margin:10px 0;font-size:clamp(2.5rem,5.2vw,4.5rem);font-weight:800;line-height:1.08}.bt-heading h1 em{color:var(--bt-accent);font-style:normal}.bt-heading p{max-width:690px;color:var(--bt-muted);margin:12px 0 0;font-size:1rem;line-height:1.65}.bt-heading-actions{flex-wrap:wrap;justify-content:flex-end;align-items:center;gap:9px;padding-bottom:5px;display:flex}.bt-clean-button,.bt-focus-button,.bt-focus-toolbar button,.bt-close-filters{border:1px solid var(--bt-border);white-space:nowrap;background:#fff;border-radius:13px;justify-content:center;align-items:center;gap:9px;padding:13px 17px;font-size:.91rem;font-weight:700;transition:background .2s,border-color .2s,transform .2s;display:inline-flex}.bt-focus-button{background:var(--bt-accent);border-color:var(--bt-accent);color:#fff}.bt-clean-button:hover,.bt-focus-toolbar button:hover{background:#f9eae0;border-color:#e5b49e}.bt-focus-button:hover{background:#b84422}.bt-main{grid-template-columns:minmax(235px,280px) minmax(0,1fr);align-items:start;gap:clamp(18px,3vw,38px);display:grid}.bt-sidebar{border:1px solid var(--bt-border);background:#fff;border-radius:22px;padding:24px 18px}.bt-side-heading{justify-content:space-between;align-items:center;margin:0 8px 22px;display:flex}.bt-close-filters{padding:6px;display:none}.bt-field{gap:8px;margin:0 4px 18px;display:grid}.bt-field>span{color:#68605b;text-transform:uppercase;letter-spacing:.06em;font-size:.78rem;font-weight:800}.bt-field select{appearance:auto;border:1px solid var(--bt-border);width:100%;min-width:0;color:var(--bt-text);background:#fffdf8;border-radius:10px;padding:12px 10px;font-size:.91rem;font-weight:600}.bt-field select:focus-visible{outline-offset:1px;outline:3px solid #e5b49e}.bt-spoiler-note{color:var(--bt-muted);margin:-6px 5px 20px;font-size:.78rem;line-height:1.6}.bt-section-title{justify-content:space-between;align-items:center;gap:10px;margin:28px 8px 12px;font-size:.82rem;font-weight:800;display:flex}.bt-section-title small{color:var(--bt-muted);font-size:.7rem;font-weight:500}.bt-section-list{gap:4px;display:grid}.bt-section-list button{text-align:left;color:#5b534f;background:0 0;border:0;border-radius:11px;justify-content:space-between;align-items:center;gap:8px;padding:11px 10px;font-size:.84rem;font-weight:650;line-height:1.35;display:flex}.bt-section-list button:hover{background:#f9eae0}.bt-section-list button.is-current{color:#873e24;background:#f9e3d8}.bt-section-list button span{align-items:baseline;gap:8px;display:flex}.bt-section-list button i{color:#998f89;font-variant-numeric:tabular-nums;font-size:.68rem;font-style:normal}.bt-section-list button small{color:#7c736d;font-variant-numeric:tabular-nums;font-size:.68rem}.bt-challenge-link{color:#873e24;text-align:left;background:#f9e3d8;border:1px solid #e5b49e;border-radius:12px;align-items:center;gap:8px;width:100%;margin-top:18px;padding:13px 12px;font-size:.84rem;font-weight:760;display:flex}.bt-challenge-link svg:last-child{margin-left:auto}.bt-challenge-link:hover,.bt-challenge-link.is-current{background:#f6d5c4}.bt-teacher-footnote{color:#857b74;margin:18px 8px 0;font-size:.74rem;line-height:1.6}.bt-stage{min-width:0}.bt-card{border:1px solid var(--bt-border);background:#fff;border-radius:26px;flex-direction:column;min-height:580px;padding:clamp(26px,4vw,54px);display:flex;box-shadow:0 20px 70px #1e454c0e}.bt-card-meta{text-transform:uppercase;letter-spacing:.07em;color:var(--bt-muted);justify-content:space-between;align-items:center;gap:14px;font-size:.7rem;font-weight:800;display:flex}.bt-card-meta>div{flex-wrap:wrap;align-items:center;gap:12px;display:flex}.bt-pill{color:#873e24;letter-spacing:0;text-transform:none;background:#f9e3d8;border-radius:999px;align-items:center;padding:7px 10px;font-size:.75rem;font-weight:750;display:inline-flex}.bt-type{color:#817770}.bt-card-counter{font-variant-numeric:tabular-nums;color:#998e87;white-space:nowrap}.bt-sentence-group{flex-direction:column;flex:1;justify-content:center;padding:clamp(50px,8vw,95px) 0 clamp(34px,5vw,65px);display:flex}.bt-speak-label{text-transform:uppercase;letter-spacing:.14em;color:#866d60;margin-bottom:19px;font-size:.72rem;font-weight:850}.bt-sentence-group h2{letter-spacing:-.065em;overflow-wrap:break-word;max-width:16ch;margin:0;font-size:clamp(2.8rem,5.9vw,6.2rem);font-weight:800;line-height:1.12}.bt-sentence-rule{background:var(--bt-accent);border-radius:999px;width:55px;height:6px;margin-top:32px}.bt-current-topic{color:#7c736d;flex-wrap:wrap;align-items:center;gap:9px;margin-bottom:23px;font-size:.85rem;display:flex}.bt-current-topic svg{color:var(--bt-accent)}.bt-dot{color:#c6b9af}.bt-reveal-controls{flex-wrap:wrap;gap:11px;display:flex}.bt-reveal-button{background:var(--bt-accent);color:#fff;border:1px solid var(--bt-accent);border-radius:13px;justify-content:center;align-items:center;gap:10px;min-height:54px;padding:16px 20px;font-weight:800;display:inline-flex}.bt-reveal-button svg:last-child{margin-left:2px;transition:transform .2s}.bt-reveal-button.is-open svg:last-child{transform:rotate(180deg)}.bt-reveal-button:hover{background:#b84422}.bt-reveal-button.bt-outline{color:#66483a;background:#fff;border-color:#e5b49e}.bt-reveal-button.bt-outline:hover{background:#fff4eb}.bt-reveal-panel{background:#fff4eb;border:1px solid #edcdbb;border-radius:16px;margin-top:17px;padding:clamp(20px,2.5vw,30px);animation:.18s ease-out bt-reveal}@keyframes bt-reveal{0%{opacity:.2;transform:translateY(-5px)}to{opacity:1;transform:translateY(0)}}.bt-panel-label{letter-spacing:.1em;color:#873e24;align-items:center;gap:9px;font-size:.7rem;font-weight:850;display:flex}.bt-reveal-panel ol,.bt-reveal-panel ul{gap:14px;margin:15px 0 0;padding-left:26px;display:grid}.bt-reveal-panel li{padding-left:5px;font-size:clamp(1rem,1.6vw,1.18rem);line-height:1.5}.bt-forms-panel{background:#fffaf5;border-color:#e2d5ca}.bt-forms-panel .bt-panel-label{color:#675e57}.bt-forms-panel li{font-size:1rem}.bt-forms-panel>small{color:#7c736d;margin-top:20px;font-size:.76rem;line-height:1.5;display:block}.bt-card-bottom{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;margin-top:25px;display:flex}.bt-source-toggle{color:#7c736d;background:0 0;border:none;align-items:center;gap:7px;padding:7px 0;font-size:.79rem;display:inline-flex}.bt-source-toggle:hover{color:#873e24}.bt-external-note{color:#8c6c49;font-size:.75rem}.bt-source-info{color:#6c625c;background:#fcf7f1;border:1px solid #e2d5ca;border-radius:12px;margin-top:6px;padding:15px 18px;font-size:.82rem}.bt-source-info strong{color:#50433a}.bt-source-info p{margin:7px 0}.bt-source-info a{color:#873e24;align-items:center;gap:5px;font-weight:700;text-decoration:underline;display:inline-flex}.bt-controls{justify-content:space-between;align-items:center;gap:18px;margin:22px 2px 0;display:flex}.bt-controls button{background:#fff;border:1px solid #dfcbbf;border-radius:13px;justify-content:center;align-items:center;gap:10px;min-height:50px;padding:15px 19px;font-weight:800;display:inline-flex}.bt-controls button.bt-next{color:#fff;background:#1f2326;border-color:#1f2326;min-width:125px}.bt-controls button:hover:not(:disabled){border-color:#e55d2e}.bt-controls button.bt-next:hover:not(:disabled){background:#34393c}.bt-progress-wrap{text-align:center;flex:1;max-width:280px}.bt-progress{background:#eadbd0;border-radius:10px;height:5px;margin-bottom:7px;overflow:hidden}.bt-progress span{background:var(--bt-accent);height:100%;transition:width .18s;display:block}.bt-progress-wrap small{color:#7c736d;font-variant-numeric:tabular-nums;font-size:.74rem}.bt-footer-hint{text-align:center;color:#988f87;margin:16px 0 10px;font-size:.74rem}.bt-focus-toolbar{display:none}.bt-hydration{position:absolute;top:-9999px}.bt-empty{border:1px solid var(--bt-border);text-align:center;background:#fff;border-radius:24px;justify-items:center;gap:15px;padding:75px 25px;display:grid}.bt-empty h2{letter-spacing:-.04em;margin:0;font-size:1.6rem}.bt-empty p{color:var(--bt-muted);margin:0 0 12px}.bt-final-card{background:#fff}.bt-final-card h2{letter-spacing:-.06em;margin:54px 0 14px;font-size:clamp(2.7rem,5vw,4.8rem);line-height:1.12}.bt-final-card h2 em{color:var(--bt-accent);font-style:normal}.bt-final-subtitle{color:#776c64;max-width:620px;margin:0 0 29px;line-height:1.65}.bt-cue-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;display:grid}.bt-cue{border:1px solid var(--bt-border);background:#fffaf5;border-radius:15px;gap:8px;padding:20px;display:grid}.bt-cue small{color:var(--bt-accent);font-weight:850}.bt-cue strong{font-size:1.16rem}.bt-cue span{color:#80766d;font-size:.84rem;line-height:1.5}.bt-final-tip{color:#72665f;padding-top:25px;line-height:1.6}.bt-app.bt-focus{z-index:9999;background:#fff;position:fixed;inset:0;overflow-y:auto}.bt-focus .bt-shell{flex-direction:column;max-width:none;height:auto;min-height:100%;padding:17px clamp(20px,3vw,50px) 22px;display:flex}.bt-focus .bt-site-header,.bt-focus .bt-heading,.bt-focus .bt-sidebar,.bt-focus .bt-footer-hint{display:none}.bt-focus .bt-focus-toolbar{justify-content:space-between;align-items:center;gap:20px;padding-bottom:12px;display:flex}.bt-focus-toolbar>div{flex-wrap:wrap;align-items:center;gap:20px;display:flex}.bt-focus-toolbar button{min-width:120px}.bt-focus-kicker{letter-spacing:.11em;color:#77564c;font-size:.8rem;font-weight:850}.bt-focus-counter{color:#a6998f;font-variant-numeric:tabular-nums;font-size:.8rem}.bt-focus .bt-main{flex:1;display:block}.bt-focus .bt-stage{flex-direction:column;min-height:calc(100vh - 95px);display:flex}.bt-focus .bt-card{box-shadow:none;border:none;flex:1;min-height:0;padding:clamp(18px,3.6vw,50px) clamp(10px,5.2vw,90px)}.bt-focus .bt-sentence-group{padding:clamp(45px,9vh,120px) 0}.bt-focus .bt-sentence-group h2{max-width:18ch;font-size:clamp(3.5rem,7vw,8.8rem)}.bt-focus .bt-current-topic{margin-bottom:18px}.bt-focus .bt-controls{margin-bottom:12px;padding:0 clamp(14px,5vw,90px)}.bt-focus .bt-final-card h2{margin-top:35px}@media (width<=1080px){.bt-main{grid-template-columns:minmax(210px,250px) minmax(0,1fr);gap:18px}.bt-card{padding:30px}.bt-sentence-group h2{font-size:clamp(2.6rem,6vw,5rem)}}@media (width<=760px){.bt-shell{padding:19px 15px 30px}.bt-heading{flex-direction:column;align-items:start;gap:18px}.bt-heading-actions{justify-content:flex-start;width:100%}.bt-main{display:block}.bt-sidebar{margin-bottom:18px;display:none}.bt-sidebar.bt-filters-open{display:block}.bt-close-filters{display:inline-flex}.bt-card{border-radius:19px;min-height:480px;padding:26px 21px}.bt-sentence-group{padding:75px 0 55px}.bt-sentence-group h2{font-size:clamp(2.8rem,8vw,4.5rem)}.bt-reveal-button{justify-content:space-between;width:100%}.bt-controls{gap:8px}.bt-controls button{padding:13px 12px;font-size:.85rem}.bt-controls button.bt-next{min-width:80px}.bt-progress-wrap{max-width:120px}.bt-cue-grid{grid-template-columns:1fr}.bt-focus .bt-shell{padding:15px 14px}.bt-focus .bt-card{padding:24px 10px}.bt-focus .bt-sentence-group h2{font-size:clamp(3.25rem,9.4vw,5rem)}.bt-focus .bt-controls{padding:0}.bt-focus-kicker{font-size:.67rem}}@media (prefers-reduced-motion:reduce){.bt-reveal-panel{animation:none}.bt-app *,.bt-app :before,.bt-app :after{scroll-behavior:auto!important;transition:none!important}}