*{box-sizing:border-box}html{color-scheme:light}body{--bg:#f9f8f3;--paper:#fffefa;--ink:#1c3442;--muted:#536c79;--line:#cfdbdf;--blue:#2766a3;--soft:#eef3f7;--green:#297b63;--amber:#976112;background:var(--bg);color:var(--ink);margin:0;font-family:"Segoe UI","Microsoft YaHei",sans-serif;font-size:16px;line-height:1.8}body.dark{color-scheme:dark;--bg:#142631;--paper:#203a48;--ink:#edf5f4;--muted:#b5c8d0;--line:#536c78;--blue:#8bbfff;--soft:#243f51;--green:#81d3b3;--amber:#e7b669}
button,input,textarea{font:inherit}button,a,input,textarea{touch-action:manipulation}button{min-height:44px;border:1px solid var(--line);border-radius:7px;padding:9px 16px;color:var(--ink);background:var(--paper);cursor:pointer;line-height:1.5;transition:background-color .18s,border-color .18s}button:hover:not(:disabled){border-color:var(--blue);background:var(--soft)}button:disabled{cursor:default;opacity:.48}button.primary{background:var(--blue);color:var(--paper);border-color:var(--blue);font-weight:600}body.dark button.primary{color:#142631}button.primary:hover:not(:disabled){filter:brightness(.95);background:var(--blue)}.text-button{border-color:transparent;background:transparent;color:var(--muted)}:focus-visible{outline:3px solid var(--blue);outline-offset:4px}a{color:var(--blue);text-underline-offset:4px}[hidden]{display:none!important}
.skip-link{position:fixed;left:20px;top:-100px;z-index:30;background:var(--paper);padding:10px}.skip-link:focus{top:10px}.site-header{height:76px;border-bottom:1px solid var(--line);padding:12px clamp(16px,4vw,56px);display:flex;gap:30px;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:13px;font-size:26px;font-weight:700;color:var(--ink);text-decoration:none;line-height:1.35}.brand>span{font-size:17px}.brand small{font-size:12px;font-weight:400;display:block;color:var(--muted)}.simulation{font-size:12px;color:var(--muted);flex:1}.site-header nav{display:flex;gap:8px}.site-header button{font-size:13px;padding:8px 12px}main{max-width:1240px;margin:auto;padding:0 28px}.intro{width:min(100%,710px);margin:clamp(38px,8vh,90px) auto 50px}.eyebrow{font-size:13px;letter-spacing:.07em;color:var(--muted);margin:0 0 14px}h1{font-size:clamp(27px,3.4vw,41px);line-height:1.35;margin:0 0 27px;letter-spacing:-.025em}h2{font-size:19px;line-height:1.5}.boss-note{padding:30px 36px;border:1px solid var(--line);border-left:3px solid var(--blue);border-radius:10px;background:var(--paper);box-shadow:0 10px 35px #14273506}.sender{display:flex;gap:12px;align-items:center;font-size:16px;line-height:1.5}.sender small{display:block;color:var(--muted);font-size:12px}.sender-mark{display:grid;place-items:center;width:40px;height:40px;background:var(--soft);color:var(--blue);border-radius:8px;font-size:16px}.boss-note blockquote{margin:24px 0 4px;font-size:21px;line-height:2}.intro-actions{display:flex;gap:10px;align-items:center;margin:30px 0 18px;flex-wrap:wrap}.intro-actions .primary{padding:14px 24px}.fine{color:var(--muted);font-size:13px;line-height:1.85}.intro-copy{color:var(--muted);margin-top:-10px}.compose-card{padding:27px;background:var(--paper);border:1px solid var(--line);border-radius:10px}.compose-card label{display:block;font-size:14px;color:var(--muted);margin-bottom:12px}textarea,input[type=text]{width:100%;background:var(--paper);color:var(--ink);border:1px solid var(--line);padding:14px;border-radius:6px;line-height:1.9}textarea{resize:vertical;min-height:150px}.compose-actions{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-top:18px}
.lesson{padding:32px 0 0}.lesson-heading{max-width:800px;margin-bottom:23px}.lesson-heading .eyebrow{margin-bottom:9px}.lesson-heading h1{font-size:30px;margin-bottom:14px}.lesson-heading>p:last-child{font-size:17px;line-height:1.9;margin:0;color:var(--ink)}.lesson-grid{display:grid;grid-template-columns:minmax(0,1.65fr) minmax(300px,1fr);gap:22px;align-items:start}.stage-frame{margin:0;min-width:0;background:var(--paper);border:1px solid var(--line);border-radius:10px;overflow:hidden}#stage{height:415px;background:var(--bg)}#stage canvas{display:block;width:100%;height:100%}.stage-frame figcaption{min-height:69px;padding:12px 18px;border-top:1px solid var(--line);font-size:13px;color:var(--muted);line-height:1.7}.stage-frame figcaption span{display:block}.detail-window{border:1px solid var(--blue);border-radius:10px;background:var(--paper);overflow:hidden;min-width:0;box-shadow:0 5px 22px #2766a30a}.detail-window>header{display:flex;align-items:center;gap:8px;padding:14px 18px;border-bottom:1px solid var(--line);background:var(--soft)}.window-dot{width:7px;height:7px;background:var(--blue);border-radius:50%;flex-shrink:0}.detail-window h2{font-size:16px;margin:0;flex:1}.detail-window #window-status{font-size:11px;color:var(--muted)}#window-lines{padding:7px 20px}#window-lines p{margin:15px 0;font-size:16px;line-height:1.9;overflow-wrap:anywhere}#draft:empty{display:none}#draft{padding:0 20px 10px}.draft-item{padding:13px 0;border-top:1px solid var(--line)}.draft-item h3{font-size:17px;line-height:1.6;margin:0 0 10px}.draft-item p{font-size:15px;line-height:1.9;margin:8px 0}.draft-item small{font-size:13px;color:var(--muted);display:block;line-height:1.8}.source-button{font-size:13px;min-height:36px;margin:4px 5px 4px 0;padding:5px 9px}.lesson-actions{position:sticky;bottom:0;background:var(--bg);display:flex;justify-content:flex-end;align-items:center;gap:8px;padding:17px 0 max(17px,env(safe-area-inset-bottom));margin-top:26px;border-top:1px solid var(--line);z-index:3}.lesson-actions #back{margin-right:auto}.lesson-actions .primary{min-width:150px}.lesson-actions #skip{font-size:13px}.lesson-actions #replay{font-size:13px}.transfer,.deeper{padding:23px 0;border-top:1px solid var(--line);margin-top:24px}.transfer h2{margin:0 0 12px}.transfer>div,.deeper>div{display:flex;gap:10px;flex-wrap:wrap}.deeper p{color:var(--muted)}.deeper #end{margin-top:15px}.transfer p[role=status]{color:var(--green)}#branch-controls:empty{display:none}#branch-controls{padding:14px 18px;border-top:1px solid var(--line)}#branch-controls button{margin:4px 3px 5px 0;font-size:14px}#branch-controls label{display:block;line-height:1.8;margin:12px 0}input[type=checkbox],input[type=radio]{width:18px;height:18px;vertical-align:middle;accent-color:var(--blue);margin-right:9px}.branch-note{color:var(--muted);font-size:13px}.error{color:var(--amber)}
dialog{width:min(680px,calc(100% - 24px));max-height:88svh;max-width:1100px;padding:0;color:var(--ink);background:var(--paper);border:1px solid var(--line);border-radius:12px;box-shadow:0 18px 70px #13263235}dialog::backdrop{background:#10212d77}.dialog-header{display:flex;align-items:center;justify-content:space-between;position:sticky;top:0;z-index:2;background:var(--paper);padding:15px 22px;border-bottom:1px solid var(--line)}.dialog-header h2{margin:0;font-size:20px}.dialog-header button{width:44px;padding:6px;font-size:24px}.dialog-header+#panel-body{padding:22px}#panel-body>p:first-child{margin-top:0}#panel-body p{line-height:1.9}#panel-body .menu{display:flex;gap:9px;flex-wrap:wrap}#panel-body label.setting{display:block;padding:12px 0}#panel-body .question-list button{display:block;width:100%;text-align:left;margin:10px 0}.answer{border-left:3px solid var(--blue);padding:5px 18px;margin:20px 0;background:var(--soft)}#panel-body h3{font-size:17px}.record{border-top:1px solid var(--line);padding:17px 0}.record p{font-size:14px;color:var(--muted)}.report-photos img{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:6px}.report-photos figure{margin:20px 0}.report-photos figcaption{font-size:13px;color:var(--muted)}.quiz-item{border-bottom:1px solid var(--line);padding:12px 0 22px}.quiz-item label{display:flex;align-items:flex-start;gap:5px;line-height:1.8;margin:13px 0}.quiz-item input{flex-shrink:0;margin-top:6px}.toast{position:fixed;top:86px;left:50%;transform:translateX(-50%);width:max-content;max-width:90%;padding:12px 20px;background:var(--ink);color:var(--paper);border-radius:7px;box-shadow:0 5px 20px #13263220;z-index:40;font-size:14px}.text-stage #stage{display:none}.text-stage .stage-frame figcaption{min-height:120px;font-size:17px;padding:24px}.text-stage .lesson-grid{grid-template-columns:1fr 1fr}
@media(min-width:1400px){main{max-width:1320px}#stage{height:465px}}
@media(max-width:759px){.site-header{height:64px;padding:9px 14px;gap:7px}.brand{font-size:22px;gap:9px}.brand>span{font-size:14px}.brand small{font-size:10px}.simulation{display:none}.site-header nav{gap:4px}.site-header button{padding:8px;font-size:12px}.site-header #pause{max-width:66px}main{padding:0 16px}.intro{margin:36px auto}.intro h1{font-size:28px;margin-bottom:23px}.boss-note{padding:22px}.boss-note blockquote{font-size:18px;line-height:1.95;margin-top:20px}.intro-actions{margin-top:25px}.intro-actions>.primary{width:100%}.intro-actions .text-button{width:100%}.fine{font-size:12px}.compose-card{padding:18px}.compose-card textarea{font-size:16px;min-height:205px}.compose-actions{align-items:stretch;flex-direction:column-reverse;gap:8px}.lesson{padding-top:25px}.lesson-heading{margin-bottom:18px}.lesson-heading h1{font-size:25px;line-height:1.5;margin-bottom:12px}.lesson-heading>p:last-child{font-size:16px;line-height:1.9}.lesson-heading .eyebrow{font-size:11px}.lesson-grid,.text-stage .lesson-grid{display:flex;flex-direction:column;gap:16px}.stage-frame,.detail-window{width:100%}#stage{height:320px}body[data-context=true] #stage{height:440px}.stage-frame figcaption{min-height:64px;padding:9px 14px;font-size:12px}.detail-window>header{padding:13px 16px}.detail-window h2{font-size:16px}#window-lines{padding:3px 18px}#window-lines p{font-size:16px}#draft{padding:0 18px 10px}.lesson-actions{padding:12px 0 max(12px,env(safe-area-inset-bottom));gap:5px;flex-wrap:wrap;margin-top:22px}.lesson-actions button{font-size:14px;padding:9px 11px}.lesson-actions #replay{display:none}.lesson-actions #back{padding-left:4px}.lesson-actions .primary{min-width:116px}.lesson-actions #skip{order:5;width:100%;min-height:34px;padding:4px}.lesson-actions #back[disabled]{display:none}.lesson-actions #branch-close{margin-left:auto}.transfer,.deeper{margin-top:21px}.transfer>div,.deeper>div{flex-direction:column}.transfer>div button,.deeper>div button{text-align:left}.dialog-header{padding:12px 16px}.dialog-header h2{font-size:18px}.dialog-header+#panel-body{padding:18px}.text-stage .stage-frame figcaption{font-size:16px;min-height:90px}}
@media(prefers-reduced-motion:reduce){button{transition:none}}@media print{.site-header,.lesson-actions,.dialog-header button,.menu,.skip-link{display:none!important}dialog[open]{position:static;display:block;max-height:none;width:100%;border:0;box-shadow:none}dialog[open]~*{display:none}body:has(dialog[open])>main{display:none}.report-photos figure{break-inside:avoid}}
.source-button{min-height:44px}.site-header button{min-width:44px}