:root{--bg: #f7f7fb;--surface: #ffffff;--surface-2: #f0f2f7;--border: #d8dde6;--text: #1f2330;--text-muted: #5a6173;--primary: #2952d3;--primary-hover: #1d40b0;--primary-soft: #e6edff;--accent: #0a7d52;--warning: #b35900;--danger: #b3261e;--shadow: 0 1px 3px rgba(0, 0, 0, .06), 0 4px 12px rgba(0, 0, 0, .04);--radius: 10px;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Hiragino Sans,Yu Gothic,Meiryo,sans-serif;color-scheme:light}@media (prefers-color-scheme: dark){:root:not([data-theme]){--bg: #0f1117;--surface: #181b25;--surface-2: #21253092;--border: #2a2f3d;--text: #e7e9f0;--text-muted: #9aa1b3;--primary: #6b8cff;--primary-hover: #889fff;--primary-soft: #1a2546;--accent: #4fd197;--warning: #f5b169;--danger: #ff8a82;--shadow: 0 1px 3px rgba(0, 0, 0, .4), 0 4px 12px rgba(0, 0, 0, .3);color-scheme:dark}}:root[data-theme=light]{--bg: #f7f7fb;--surface: #ffffff;--surface-2: #f0f2f7;--border: #d8dde6;--text: #1f2330;--text-muted: #5a6173;--primary: #2952d3;--primary-hover: #1d40b0;--primary-soft: #e6edff;--accent: #0a7d52;--warning: #b35900;--danger: #b3261e;--shadow: 0 1px 3px rgba(0, 0, 0, .06), 0 4px 12px rgba(0, 0, 0, .04);color-scheme:light}:root[data-theme=dark]{--bg: #0f1117;--surface: #181b25;--surface-2: #21253092;--border: #2a2f3d;--text: #e7e9f0;--text-muted: #9aa1b3;--primary: #6b8cff;--primary-hover: #889fff;--primary-soft: #1a2546;--accent: #4fd197;--warning: #f5b169;--danger: #ff8a82;--shadow: 0 1px 3px rgba(0, 0, 0, .4), 0 4px 12px rgba(0, 0, 0, .3);color-scheme:dark}*{box-sizing:border-box}html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font-size:16px;line-height:1.6}#app{max-width:980px;margin:0 auto;padding:24px 20px 80px}header.app-header{display:flex;align-items:baseline;justify-content:space-between;flex-wrap:wrap;gap:8px;margin-bottom:20px}header.app-header h1{margin:0;font-size:24px;font-weight:700;letter-spacing:-.01em}header.app-header .tagline{color:var(--text-muted);font-size:13px}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:18px 20px;margin-bottom:16px}.card h2{margin:0 0 12px;font-size:16px;letter-spacing:.02em;color:var(--text-muted);text-transform:uppercase;font-weight:600}.config-bar{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:12px}.field{display:flex;flex-direction:column;gap:4px}.field label{font-size:12px;color:var(--text-muted);font-weight:600}select,input[type=text],button{font:inherit;color:var(--text)}select,input[type=text]{background:var(--surface-2);border:1px solid var(--border);border-radius:6px;padding:8px 10px;width:100%;outline-offset:2px}select:focus,input:focus,button:focus{outline:2px solid var(--primary)}.button-row{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}button{cursor:pointer;border:1px solid var(--border);background:var(--surface-2);color:var(--text);padding:8px 14px;border-radius:6px;font-weight:500;transition:background .15s,border-color .15s}button:hover{background:var(--primary-soft);border-color:var(--primary)}button.primary{background:var(--primary);border-color:var(--primary);color:#fff}button.primary:hover{background:var(--primary-hover);border-color:var(--primary-hover)}button.subtle{background:transparent}button:disabled{opacity:.5;cursor:not-allowed}.problem-title{font-size:20px;font-weight:700;margin:0 0 4px}.problem-meta{font-size:12px;color:var(--text-muted);margin-bottom:12px}.problem-body{font-size:17px;line-height:1.8;background:var(--surface-2);border-left:4px solid var(--primary);padding:14px 16px;border-radius:6px;white-space:pre-wrap}.seed-bar{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:14px;font-size:13px}.seed-bar code{background:var(--surface-2);border:1px solid var(--border);padding:4px 8px;border-radius:4px;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:12.5px;word-break:break-all}.seed-bar input{flex:1 1 280px;min-width:200px;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:12.5px}.toast{position:fixed;bottom:24px;left:50%;transform:translate(-50%);background:var(--text);color:var(--bg);padding:10px 16px;border-radius:999px;font-size:14px;box-shadow:var(--shadow);z-index:100;opacity:0;transition:opacity .2s;pointer-events:none}.toast.show{opacity:1}.disclosure{margin-top:16px;border:1px solid var(--border);border-radius:var(--radius);background:var(--surface)}.disclosure summary{cursor:pointer;padding:12px 16px;font-weight:600;list-style:none;display:flex;align-items:center;gap:8px}.disclosure summary::-webkit-details-marker{display:none}.disclosure summary:before{content:"▶";font-size:11px;transition:transform .15s;color:var(--text-muted)}.disclosure[open]>summary:before{transform:rotate(90deg)}.disclosure .disclosure-body{padding:0 16px 16px}.answer-final{background:var(--primary-soft);border-radius:6px;padding:12px 14px;font-size:18px;margin-bottom:4px}.solution-step{margin-bottom:14px;padding-left:12px;border-left:3px solid var(--accent)}.solution-step h4{margin:0 0 4px;font-size:14px;color:var(--accent)}.solution-step .body{font-size:15px;line-height:1.7}.mistake-card{background:var(--surface-2);border-left:3px solid var(--warning);padding:10px 14px;border-radius:6px;margin-bottom:10px}.mistake-card .wrong{color:var(--danger);font-weight:600;margin-bottom:4px}.mistake-card .cause{font-size:14px;margin-bottom:4px}.mistake-card .hint{font-size:14px;color:var(--text-muted)}.error{color:var(--danger);background:#ffebec;border:1px solid var(--danger);padding:10px 14px;border-radius:6px;font-size:14px}@media (prefers-color-scheme: dark){:root:not([data-theme]) .error{background:#3a1715}}:root[data-theme=dark] .error{background:#3a1715}footer{margin-top:32px;text-align:center;font-size:12px;color:var(--text-muted)}.katex{font-size:1em}.katex-display{margin:.6em 0!important;overflow-x:auto;overflow-y:hidden}@media (max-width: 600px){#app{padding:16px 12px 60px}header.app-header h1{font-size:20px}.problem-title{font-size:18px}}.app-subtitle{font-weight:400;font-size:.8em;color:var(--text-muted)}.muted{color:var(--text-muted)}.small{font-size:12.5px}.search-bar{display:flex;gap:8px;margin-bottom:12px}.search-bar input{flex:1}.browser-body{display:flex;flex-direction:column;gap:16px;max-height:60vh;overflow-y:auto;padding-right:4px}.domain-block{border-top:2px solid var(--border);padding-top:10px}.domain-block:first-child{border-top:none;padding-top:0}.domain-block h3{margin:0 0 8px;font-size:16px;letter-spacing:.02em}.subject-block{margin:0 0 14px 4px}.subject-block h4{margin:0 0 4px;font-size:14px;font-weight:600;color:var(--accent)}.topic-chips{display:flex;flex-wrap:wrap;gap:6px;margin-top:6px}.topic-chip{padding:4px 10px;font-size:13px;border-radius:999px;background:var(--surface-2);border:1px solid var(--border);cursor:pointer}.topic-chip:hover:not(:disabled){background:var(--primary-soft);border-color:var(--primary)}.topic-chip:disabled,.topic-chip.disabled{cursor:not-allowed;opacity:.55;font-style:italic}.tag-row{display:flex;flex-wrap:wrap;gap:6px;margin:6px 0 10px}.tag{background:var(--surface-2);border:1px solid var(--border);color:var(--text-muted);padding:2px 8px;border-radius:4px;font-size:11.5px;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}.tag-clickable{cursor:pointer;transition:background .12s,border-color .12s,color .12s}.tag-clickable:hover{background:var(--primary-soft);border-color:var(--primary);color:var(--primary)}.choices{display:flex;flex-direction:column;gap:8px;margin:14px 0 6px}.choice-btn{display:flex;align-items:flex-start;gap:10px;text-align:left;background:var(--surface-2);border:1px solid var(--border);border-radius:8px;padding:12px 14px;font-size:15px;width:100%;cursor:pointer;transition:background .12s,border-color .12s}.choice-btn:hover:not(.correct):not(.incorrect){background:var(--primary-soft);border-color:var(--primary)}.choice-btn .choice-letter{font-weight:700;color:var(--text-muted);min-width:1.6em}.choice-btn .choice-text{flex:1}.choice-btn.correct{background:#0f99601f;border-color:var(--accent);color:var(--text)}.choice-btn.incorrect{background:#b3261e1a;border-color:var(--danger)}.choice-feedback{margin-top:4px;font-size:14px;font-weight:600}.choice-feedback.correct{color:var(--accent)}.choice-feedback.incorrect{color:var(--danger)}@media (prefers-color-scheme: dark){:root:not([data-theme]) .choice-btn.correct{background:#4fd19729}:root:not([data-theme]) .choice-btn.incorrect{background:#ff8a8224}}:root[data-theme=dark] .choice-btn.correct{background:#4fd19729}:root[data-theme=dark] .choice-btn.incorrect{background:#ff8a8224}*:focus{outline:none}*:focus-visible{outline:3px solid var(--primary);outline-offset:2px;border-radius:4px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.header-tools{display:flex;gap:8px;flex-wrap:wrap}.header-tools button{padding:6px 12px;font-size:13px}.lang-wrapper{display:inline-flex;align-items:center;gap:4px}.lang-icon{font-size:14px;line-height:1}.lang-select{padding:6px 24px 6px 10px;font-size:12px;font-weight:500;letter-spacing:.03em;border:1px solid var(--border);border-radius:6px;background:var(--surface-2);color:var(--text);cursor:pointer;min-width:56px;appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%235a6173' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 6px center;background-size:12px;transition:border-color .15s,background-color .15s}.lang-select:hover{border-color:var(--primary);background-color:var(--surface)}.lang-select:focus{outline:2px solid var(--primary);outline-offset:1px;background-color:var(--surface)}:root[data-theme=dark] .lang-select{background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%239aa1b3' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E")}@media (prefers-color-scheme: dark){:root:not([data-theme]) .lang-select{background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%239aa1b3' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E")}}.theme-toggle{display:inline-flex;align-items:center;gap:4px}.theme-toggle .theme-icon{font-size:14px}.fav-btn{border:1px solid var(--border);background:transparent;cursor:pointer;padding:4px 10px;font-size:14px;border-radius:6px}.fav-btn.starred{color:var(--warning);border-color:var(--warning);background:#ffc8641a}.fav-btn:hover{background:var(--primary-soft)}.history-list,.fav-list{display:flex;flex-direction:column;gap:6px;max-height:320px;overflow-y:auto}.history-item,.fav-item{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:8px 12px;border:1px solid var(--border);border-radius:6px;background:var(--surface-2);font-size:13px}.history-item:hover,.fav-item:hover{background:var(--primary-soft);border-color:var(--primary)}.history-item .meta,.fav-item .meta{flex:1;min-width:0}.history-item .title,.fav-item .title{font-weight:600;color:var(--text);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.history-item .seed,.fav-item .seed{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:11px;color:var(--text-muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.history-item button,.fav-item button{flex-shrink:0;font-size:12px;padding:4px 10px}.danger{color:var(--danger);border-color:var(--danger)}.danger:hover{background:#b3261e14;border-color:var(--danger)}.worksheet-form{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:12px;margin-bottom:12px}.worksheet-form label{font-size:12px;color:var(--text-muted);font-weight:600;display:block;margin-bottom:4px}.worksheet-form input[type=number],.worksheet-form input[type=text],.worksheet-form select{width:100%;background:var(--surface-2);border:1px solid var(--border);border-radius:6px;padding:8px 10px;color:var(--text);font:inherit}.worksheet-mix{display:flex;gap:8px;flex-wrap:wrap}.worksheet-mix label{display:block;font-size:11px}.worksheet-mix input{width:70px}.worksheet-summary{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:12px;font-size:13px;color:var(--text-muted)}.worksheet-summary code{background:var(--surface-2);padding:2px 6px;border-radius:4px;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:11.5px}.worksheet-items{display:flex;flex-direction:column;gap:14px}.ws-item{border:1px solid var(--border);border-radius:var(--radius);background:var(--surface);padding:14px 18px;page-break-inside:avoid;break-inside:avoid}.ws-item .ws-num{display:inline-block;background:var(--primary);color:#fff;border-radius:4px;padding:1px 8px;font-weight:700;font-size:13px;margin-bottom:6px}.ws-item .ws-meta{font-size:11.5px;color:var(--text-muted);margin-bottom:4px}.ws-item .ws-title{font-size:16px;font-weight:700;margin:0 0 6px}.ws-item .ws-question{background:var(--surface-2);border-left:3px solid var(--primary);padding:10px 12px;border-radius:4px;white-space:pre-wrap;margin-bottom:8px}.ws-item .ws-choices{margin-top:8px;list-style:upper-alpha;padding-left:28px}.ws-item .ws-choices li{margin-bottom:2px}.ws-answer{border-top:1px dashed var(--border);margin-top:8px;padding-top:8px;font-size:14px}.ws-answer .ws-answer-label{font-weight:700;color:var(--accent);margin-right:6px}.ws-seed{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:10.5px;color:var(--text-muted);margin-top:4px}.answers-page{margin-top:24px;padding-top:16px;border-top:2px solid var(--border);page-break-before:always;break-before:page}.answers-page h2{margin:0 0 12px}.answers-page .answer-row{padding:6px 0;border-bottom:1px solid var(--border);font-size:14px}.answers-page .answer-row .ws-num{display:inline-block;font-weight:700;margin-right:8px;min-width:2em}@media print{:root,:root[data-theme=light],:root[data-theme=dark]{--bg: #ffffff !important;--surface: #ffffff !important;--surface-2: #f5f5f5 !important;--border: #888888 !important;--text: #000000 !important;--text-muted: #444444 !important;--primary: #000000 !important;--primary-soft: #eeeeee !important;--accent: #000000 !important;--warning: #000000 !important;--danger: #000000 !important;--shadow: none !important;color-scheme:light!important}body,html,#app{background:#fff!important;color:#000!important;font-size:12pt;padding:0!important;margin:0!important;max-width:100%!important}.app-header .header-tools,.config-bar,.button-row,.browser-body,.search-bar,#browserCard,.tag-row,#worksheetForm .button-row,.seed-bar input,.seed-bar button,.toast,.disclosure summary,.fav-btn,.history-list,.fav-list,#historyCard,#favoritesCard,#seedCard,#problemCard,footer,.no-print{display:none!important}.ws-item{box-shadow:none!important;border:1px solid #999!important;page-break-inside:avoid!important;break-inside:avoid!important}.answers-page{page-break-before:always!important;break-before:page!important}a{color:#000;text-decoration:underline}@page{margin:18mm 14mm 22mm}@page{@bottom-center{content:"ProblemForge — " counter(page) " / " counter(pages);font-size:9pt;color:#666}@top-right{content:string(print-master-seed);font-size:8pt;color:#999}}.print-master-seed{string-set:print-master-seed content();display:none!important}.ws-seed{color:#666!important}.print-footer{display:block!important;text-align:center;font-size:9pt;color:#666;margin-top:8mm;border-top:1px solid #ccc;padding-top:4mm}.print-footer .pf-page-info{display:none}.print-footer .pf-help{display:block;font-size:8pt;margin-top:2mm}.katex,.katex-display{page-break-inside:avoid!important;break-inside:avoid!important}}.print-footer,.ws-item.questions-only .ws-answer,.ws-item.hints-only .ws-answer{display:none}.ws-item.hints-only .ws-hints{display:block;margin-top:8px;font-size:13px;color:var(--text-muted);background:var(--surface-2);border-left:3px solid var(--warning);padding:8px 12px;border-radius:4px}.ws-item .ws-hints{display:none}.ws-item.with-answers .ws-answer,.ws-item.with-explanations .ws-answer{display:block}.ws-item .ws-explanation{display:none}.ws-item.with-explanations .ws-explanation{display:block;margin-top:10px;border-top:1px dashed var(--border);padding-top:8px;page-break-inside:avoid;break-inside:avoid}.ws-item.with-explanations .ws-solution-steps,.ws-item.with-explanations .ws-mistakes{margin-top:6px;font-size:13px;background:var(--surface-2);border-left:3px solid var(--accent);padding:8px 12px;border-radius:4px}.ws-item.with-explanations .ws-mistakes{border-left-color:var(--warning);margin-top:8px}.ws-item.with-explanations .ws-solution-step{display:block;margin:4px 0}.ws-item.with-explanations .ws-step-heading{display:block;font-weight:600;color:var(--accent);font-size:12.5px}.ws-item.with-explanations .ws-step-body{display:block;margin-left:8px;font-size:13px;line-height:1.65}.ws-item.with-explanations .ws-mistake{display:block;margin:6px 0;padding:4px 0;border-bottom:1px dotted var(--border)}.ws-item.with-explanations .ws-mistake:last-child{border-bottom:none}.ws-item.with-explanations .ws-mistake-wrong{display:block;color:var(--danger);font-weight:600;font-size:13px}.ws-item.with-explanations .ws-mistake-cause,.ws-item.with-explanations .ws-mistake-hint{display:block;font-size:12.5px;margin-top:2px;color:var(--text-muted)}@media print{.ws-item.with-explanations .ws-explanation{display:block!important}.ws-item.with-explanations .ws-solution-steps,.ws-item.with-explanations .ws-mistakes{background:#f5f5f5!important;border-left-color:#444!important}.ws-item.with-explanations .ws-mistake-wrong{color:#000!important}}.app-header{align-items:center!important}.modal-backdrop{position:fixed;inset:0;background:#00000073;z-index:100;display:flex;align-items:flex-start;justify-content:center;padding:5vh 4vw;overflow-y:auto}.modal{background:var(--surface);color:var(--text);border:1px solid var(--border);border-radius:8px;max-width:720px;width:100%;box-shadow:0 12px 32px #00000024;display:flex;flex-direction:column;max-height:90vh}.modal-wide{max-width:960px}.modal-header{display:flex;justify-content:space-between;align-items:center;padding:14px 18px;border-bottom:1px solid var(--border)}.modal-header h2{margin:0;font-size:18px}.modal-close{font-size:22px;line-height:1;padding:2px 10px;min-height:32px}.modal-body{padding:14px 18px;overflow-y:auto}.modal-body h3{margin:18px 0 8px;font-size:15px;border-bottom:1px solid var(--border);padding-bottom:4px}.hotkey-list{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:6px;list-style:none;padding:0}.hotkey-list kbd{display:inline-block;padding:2px 8px;background:var(--surface-2);border:1px solid var(--border);border-radius:4px;font-family:var(--font-mono, monospace);font-size:12px;margin-right:6px}.exp-preview{margin-top:8px}.exp-preview pre{background:var(--surface-2);padding:8px 10px;border-radius:6px;font-size:11px;max-height:200px;overflow:auto}.exp-result{padding:8px 12px;border-radius:6px;border-left:3px solid var(--primary);background:var(--surface-2);font-size:13px}.exp-result.ok{border-left-color:var(--success, #22c55e)}.exp-result.warn{border-left-color:var(--warning, #f59e0b)}.exp-options label{display:inline-flex;align-items:center;gap:4px;font-size:13px}.topic-tree{margin-top:8px;display:flex;flex-direction:column;gap:8px}.domain-tree{border:1px solid var(--border);border-radius:6px;padding:6px 10px;background:var(--surface-2)}.domain-tree summary{cursor:pointer;padding:4px 0;font-size:14px}.subject-tree{margin:8px 0;padding:8px;background:var(--surface);border-radius:4px;border:1px solid var(--border)}.subject-tree-header{display:flex;align-items:center;gap:6px;margin-bottom:6px;flex-wrap:wrap}.subject-tree-header h4{margin:0 0 0 auto;font-size:14px;color:var(--text-muted)}.topic-checkboxes{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:4px 12px}.topic-checkbox{display:flex;align-items:center;gap:6px;padding:4px 6px;border-radius:4px;cursor:pointer;font-size:13px}.topic-checkbox:hover{background:var(--surface-2)}.topic-checkbox input[type=checkbox]{margin:0;flex:0 0 auto}#topicSelCounter{color:var(--primary)}.print-master-seed{display:none}@media (max-width: 720px){.modal-backdrop{padding:2vh 2vw}.modal{max-height:95vh}}
