:root{font-family:Inter,"Segoe UI","Microsoft YaHei",sans-serif;color:#202630;background:#eef0f3;font-synthesis:none;--blue:#386bf1;--muted:#7a8290;--line:rgba(43,58,83,.11)}*{box-sizing:border-box}body{margin:0;overflow:hidden}button,select,input{font:inherit}button{cursor:pointer;border:0;background:transparent;color:inherit;touch-action:manipulation}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #638df7;outline-offset:4px}button:disabled{opacity:.3;cursor:default}.hidden{display:none!important}#stage{position:fixed;inset:0;touch-action:none}#stage canvas{width:100%;height:100%;display:block}header{position:fixed;top:32px;left:42px;right:42px;z-index:10;display:flex;justify-content:space-between;align-items:center}.brand{display:flex;align-items:center;gap:10px;font-size:20px;font-weight:700;letter-spacing:-.5px}.logo{font-size:30px;color:var(--blue)}.version{font-size:12px;letter-spacing:1px;color:var(--muted);border-left:1px solid #cfd4dc;padding-left:14px;margin-left:8px;font-weight:400}.tools{display:flex;gap:8px}.tools button{background:#ffffff8c;border:1px solid #fff9;border-radius:30px;padding:10px 16px;font-size:12px}.tools button[aria-pressed=false]{color:#939aa6}#hero{position:fixed;left:6.2vw;top:31%;z-index:2;pointer-events:none}#hero button{pointer-events:auto}.eyebrow{text-transform:uppercase;letter-spacing:2px;font-size:12px;color:#6c7687;display:flex;align-items:center;gap:10px}.eyebrow>span{width:6px;height:6px;border-radius:100%;background:var(--blue)}h1{font-size:clamp(40px,5.1vw,78px);line-height:1.2;letter-spacing:-3px;margin:22px 0;font-weight:750}h1 span{color:#242f44}#hero>p{font-size:17px;line-height:1.9;color:#747e8d;margin:0 0 28px}.primary{background:var(--blue);color:white;padding:16px 24px;border-radius:30px;box-shadow:0 8px 28px #386bf13b;font-weight:600;font-size:15px}.primary span{padding-left:28px}.primary:hover{background:#2458da;transform:translateY(-2px)}.heroFoot{display:flex;gap:22px;align-items:center;margin-top:65px;color:#8b929e;font-size:11px;letter-spacing:.8px}.heroFoot span:first-child{font-family:monospace;color:#4e648d}.glass{background:#ffffffde;border:1px solid #fff;border-radius:20px;box-shadow:0 12px 48px #26374b0b;backdrop-filter:blur(20px)}#lesson{position:fixed;top:130px;left:42px;width:338px;max-height:calc(100dvh - 252px);overflow:auto;padding:25px 25px 0;z-index:5;scrollbar-width:thin}.cardHead{display:flex;justify-content:space-between;color:var(--blue);font-size:11px;letter-spacing:1.5px;font-weight:600}.cardHead span:last-child{color:#9aa1ad;font-family:monospace}h2{font-size:25px;line-height:1.5;letter-spacing:-.8px;margin:15px 0 10px}#lessonText{font-size:13px;line-height:1.9;color:#737e8d;margin:0 0 22px}.control{margin:20px 0}.control label{display:flex;justify-content:space-between;font-size:12px;color:#637083}.control output{color:#2c56b9;font-variant-numeric:tabular-nums;font-weight:600}.control input[type=range]{display:block;width:100%;accent-color:var(--blue);margin:15px 0 8px;cursor:pointer;height:5px}.rangeEnds{display:flex;justify-content:space-between;color:#a1a7b0;font-size:10px}.presets{display:flex;gap:5px;flex-wrap:wrap;margin-top:14px}.presets button{padding:7px 10px;border-radius:8px;background:#eef2f9;color:#69778e;font-size:11px}.presets button.active{background:#e1eaff;color:#315fcb}.readouts{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:18px 0}.readout{background:#f3f5f8;border-radius:11px;padding:12px}.readout small{display:block;font-size:10px;color:#8c94a1}.readout b{display:block;font-size:21px;font-weight:500;margin-top:5px;letter-spacing:-.5px}.readout b em{font-size:11px;font-style:normal;color:#8e97a5;margin-left:3px}.insight{border-top:1px solid var(--line);padding-top:15px;margin-top:20px}.insight>span{font-size:10px;letter-spacing:2px;color:var(--blue)}.insight p{font-size:12px;line-height:1.8;color:#667181;margin:7px 0 15px}details{font-size:11px;color:#89919c;line-height:1.8}summary{cursor:pointer}details p{color:#758091}.stepNav{display:flex;align-items:center;justify-content:space-between;position:sticky;bottom:0;background:#fff;padding:16px 0;margin-top:18px;border-top:1px solid var(--line)}.stepNav button{font-size:12px;padding:7px}.stepNav #next{color:var(--blue)}#dots{display:flex;gap:6px}#dots button{height:6px;width:6px;padding:0;border-radius:50%;background:#dfe4ec}#dots button.active{background:var(--blue);width:18px;border-radius:5px}#chapters{position:fixed;bottom:28px;left:50%;transform:translateX(-50%);padding:6px;display:flex;z-index:10;gap:4px;border-radius:40px;white-space:nowrap}#chapters button{padding:12px 19px;border-radius:30px;color:#7b8594;font-size:12px;transition:.25s}#chapters button span{margin-right:7px;font-size:10px;opacity:.6}#chapters button.active{background:#253044;color:white;box-shadow:0 3px 8px #0002}#observer{position:fixed;bottom:157px;right:36px;width:270px;padding:18px;z-index:4}.observerHead{display:flex;justify-content:space-between;font-size:11px;color:#59677a}.liveDot{color:#8b95a3;font-size:9px}.liveDot:before{content:'';display:inline-block;width:5px;height:5px;background:#8fac9a;border-radius:50%;margin-right:5px}.observerBody{display:flex;align-items:center;gap:16px;padding:13px 0}.observerBody canvas{width:90px;height:90px}.observerBody strong{font-size:18px;font-weight:500}.observerBody p{font-size:11px;color:#808c9d;margin:9px 0 6px}.observerBody span{font-size:10px;color:#929aa6}.observerFoot{font-size:9px;color:#a2a9b2;border-top:1px solid var(--line);padding-top:10px}#transport{position:fixed;right:36px;bottom:101px;display:flex;align-items:center;gap:12px;padding:8px 14px;z-index:4;font-size:11px;border-radius:30px}#play{background:#edf2ff;color:var(--blue);border-radius:50%;width:28px;height:28px}#clockLabel{min-width:90px;color:#738097}#transport label{font-size:10px;color:#9ba3b0;border-left:1px solid var(--line);padding-left:10px}select{border:0;background:transparent;color:#52637e;font-size:10px}#viewTools{position:fixed;top:110px;left:56%;display:flex;align-items:center;gap:4px;transform:translateX(-30%);z-index:4;white-space:nowrap}#viewTools button{font-size:11px;color:#97a0ad;padding:8px 12px;border-radius:20px}#viewTools button.active{color:#43619c;background:#fff9}#viewTools>span{font-size:10px;color:#a0a8b3;margin-left:12px}#modelNote{position:fixed;bottom:13px;right:24px;font-size:9px;color:#9ba4b0;letter-spacing:.5px}#sceneLabels{position:fixed;inset:0;pointer-events:none;z-index:1}#sceneLabels>span{position:absolute;background:#ffffffc9;box-shadow:0 3px 16px #182e4b08;border:1px solid #fff;border-radius:7px;padding:8px 12px;font-size:11px;white-space:nowrap;transform:translate(-50%,-100%)}#sceneLabels i{font-size:8px;letter-spacing:1.6px;font-style:normal;color:#a4adba;margin-left:8px}#sunLabel{color:#c78b32}#loading{position:fixed;inset:0;display:grid;place-content:center;z-index:50;background:#eef0f3;color:#60708a;font-size:14px}dialog{width:min(520px,90vw);border:1px solid white;border-radius:24px;padding:35px;box-shadow:0 30px 100px #263b4c33;color:#253044}dialog::backdrop{background:#25304544;backdrop-filter:blur(6px)}dialog .close{position:absolute;right:20px;top:12px;font-size:27px;color:#9aa3b1}dialog p{color:#8c95a3;font-size:13px}#questionList{display:grid;gap:8px;margin:24px 0}#questionList button{text-align:left;border-radius:12px;background:#f2f5fa;padding:16px;font-size:13px}#questionList button:hover{color:var(--blue);background:#e9f0ff}dialog small{font-size:10px;color:#a1a9b4}.entering #hero{animation:fadeout .4s forwards}.lab #hero{display:none}@keyframes fadeout{to{opacity:0;transform:translateY(15px)}}@media(min-width:1500px){#lesson{left:5vw;top:16vh;width:360px}#observer{right:5vw}#transport{right:5vw}}@media(max-height:750px) and (min-width:761px){#lesson{top:95px;max-height:calc(100dvh - 190px);padding:20px 20px 0}#lesson h2{font-size:22px}.control{margin:14px 0}#observer{bottom:142px}#viewTools{top:92px}}@media(max-width:760px){header{top:18px;left:18px;right:18px}.brand{font-size:16px;gap:6px}.logo{font-size:25px}.version{display:none}.tools{gap:4px}.tools button{padding:8px 10px;font-size:10px}#hero{left:7%;top:auto;bottom:12%}h1{font-size:42px;letter-spacing:-2px}#hero>p{font-size:14px}.heroFoot{margin-top:28px;font-size:9px;gap:12px}#lesson{left:14px;top:auto;bottom:91px;width:calc(100% - 28px);max-height:38dvh;padding:18px 20px 0;border-radius:18px}#lesson h2{font-size:21px;margin:8px 0}#lessonText{margin-bottom:12px;font-size:12px}.control{margin:14px 0}.insight{margin-top:12px}.stepNav{margin-top:12px;padding:9px 0}#chapters{bottom:25px;max-width:calc(100vw - 20px);overflow:auto;padding:5px;gap:0}#chapters button{font-size:11px;padding:11px 12px}#chapters button span{display:none}#observer{right:14px;top:99px;bottom:auto;width:156px;padding:12px;pointer-events:none}.observerHead{font-size:10px}.liveDot{display:none}.observerBody{gap:9px;padding:8px 0}.observerBody canvas{width:48px;height:48px}.observerBody strong{font-size:13px}.observerBody p{font-size:9px;margin:5px 0}.observerBody span{font-size:8px}.observerFoot{display:none}#transport{top:183px;bottom:auto;right:14px;padding:4px 9px;gap:7px;font-size:9px}#clockLabel{min-width:70px}#transport label{display:none}#viewTools{left:15px;top:75px;transform:none;display:block}#viewTools button{padding:6px 8px;font-size:10px}#viewTools>span{display:block;font-size:9px;margin-top:8px}#modelNote{bottom:7px;font-size:8px;right:15px}#sceneLabels>span{font-size:9px;padding:5px 8px}#sceneLabels i{display:none}}

/* Language controls keep the existing desktop composition. */
.language-switch{display:inline-flex;gap:3px;padding:4px;border:1px solid #d8dfeb;border-radius:25px;background:#ffffffb8;align-items:center;flex-shrink:0}
.tools .language-switch button{font-size:12px;min-width:32px;padding:7px 8px;border:0;background:transparent}
.tools .language-switch button[aria-pressed=true]{background:#3b6ff5;color:#fff}
html:not([lang^=zh]) #hero h1{font-size:clamp(38px,4.5vw,66px);max-width:680px;line-height:1.12}
html:not([lang^=zh]) #lesson h2{font-size:clamp(24px,2.2vw,34px);line-height:1.2}
html:not([lang^=zh]) #lesson p{line-height:1.65}
html:not([lang^=zh]) .tools>button{padding:10px 14px}
html:not([lang^=zh]) #chapters button{padding:14px 18px;white-space:normal}
html:not([lang^=zh]) #chapterTag{font-size:11px;letter-spacing:1px}
html:not([lang^=zh]) #observer{width:330px}
html:not([lang^=zh]) .observerHead{font-size:12px;gap:8px}
html:not([lang^=zh]) #phaseAge{font-size:11px}
html:not([lang^=zh]) #transport{font-size:12px;max-width:calc(100vw - 30px)}
html:not([lang^=zh]) #aigcPanel button{white-space:normal;overflow-wrap:anywhere;line-height:1.4}
html:not([lang^=zh]) #aigcPanel select{max-width:100%}
html:not([lang^=zh]) #aigcPanel h3{line-height:1.4}
@media(max-width:1100px){header .version{display:none}.tools{gap:5px}.tools>button{font-size:12px!important;padding:9px 10px!important}}