:root{font-family:"Microsoft YaHei UI","Microsoft YaHei","PingFang SC",sans-serif;color:#142f49;background:#fff;--blue:#2563eb;--ink:#142f49;--muted:#72869e;--line:#dce6f1;--canvas:#f0f5fb;--purple:#9277c9;--gold:#ae7a25;font-synthesis:none}*{box-sizing:border-box}body{margin:0;overflow:hidden}button,input,select{font:inherit}button{cursor:pointer;border:1px solid var(--line);background:#fff;color:var(--ink);border-radius:7px;padding:8px 11px;font-size:12px;line-height:1.35}button:hover{border-color:#9cb7e8;background:#f4f7ff}button:disabled{cursor:default;opacity:.45}button.primary,button.active{color:#fff;background:var(--blue);border-color:var(--blue)}button:focus-visible,input:focus-visible,select:focus-visible,.viewport:focus-visible{outline:3px solid #90b8ff;outline-offset:3px}button.text-button{border:0;padding:5px 0;color:#436a9c;background:none}header{height:76px;background:var(--ink);display:flex;align-items:center;justify-content:space-between;padding:0 25px;gap:15px;color:#fff}.brand{display:flex;align-items:center;gap:10px;color:inherit;text-decoration:none;font-size:22px;font-weight:700}.brand svg{width:35px;height:35px;fill:#142f49;stroke:#a8d1ff;stroke-width:1.5}.brand small{display:block;font-size:10px;font-weight:400;color:#bed0e4;letter-spacing:1px;margin-top:4px}.header-actions{display:flex;gap:8px}.header-actions button{color:#e6effa;border-color:#48617a;background:#25435f}.header-actions button:hover{background:#355a7e}.header-actions .primary{background:#2563eb}.mobile{display:none}main{height:calc(100dvh - 105px);display:grid;grid-template-columns:216px minmax(0,1fr) 330px;min-height:0}aside{min-height:0;background:#fff}#library{padding:24px 17px 16px;border-right:1px solid var(--line);display:flex;flex-direction:column;gap:16px}.library-heading{display:flex;align-items:start;flex-direction:column;gap:5px}.library-heading h2{font-size:15px;margin:0}.library-heading span{font-size:10px;color:var(--muted)}.search input{width:100%;padding:10px 11px;border:1px solid var(--line);border-radius:7px;color:var(--ink);font-size:11px;background:#f9fbfe}.search input::placeholder{color:#8c9db1}#model-list{flex:1;min-height:0;overflow-y:auto;scrollbar-width:thin;padding-right:3px}.model-group h3{font-size:11px;font-weight:500;color:var(--muted);margin:16px 0 9px}.model-group:first-child h3{margin-top:0}.model-button{display:flex;width:100%;text-align:left;align-items:center;gap:9px;padding:10px 8px;margin-bottom:6px;border:1px solid transparent;background:#f5f8fc;border-radius:7px}.model-button strong{display:block;font-size:12px;font-weight:500}.model-button small{font-size:9px;color:var(--muted);display:block;margin-top:3px}.model-button.active{color:#1b4fbe;background:#eaf1ff;border-color:#b6cbfa}.formula-symbol{font-family:Cambria,Georgia,serif;font-size:14px;min-width:51px;color:#3e5e82}.model-button.active .formula-symbol{color:#225acd}.library-foot{border-top:1px solid var(--line);padding-top:14px}.library-foot p{color:var(--muted);font-size:10px;line-height:1.9;margin:10px 0 6px}.library-foot #builder-open{width:100%;display:flex;justify-content:space-between;align-items:center;color:#49679b;background:#f8faff}.workspace{position:relative;min-width:0;min-height:0;background:var(--canvas);overflow:hidden}.workspace-heading{position:absolute;top:29px;left:27px;right:27px;display:flex;justify-content:space-between;align-items:center;z-index:3;pointer-events:none}.workspace-heading p{font-size:11px;color:var(--muted);margin:0 0 7px}h1{font-size:29px;line-height:1.2;margin:0;letter-spacing:.4px}h1 small{font-family:Cambria,Georgia,serif;font-size:20px;color:#6d85a1;font-weight:400;letter-spacing:0;margin-left:7px}#model-badge{font-size:10px;color:#64819f;border:1px solid #d2e1f0;padding:8px 10px;border-radius:6px;background:#ffffffc9}.mode-tabs{position:absolute;left:27px;top:108px;display:flex;gap:2px;background:#e4ecf7;padding:4px;border-radius:9px;z-index:4}.mode-tabs button{font-size:11px;padding:8px 10px;border:0;background:transparent;color:#627c9a}.mode-tabs button.active{background:#fff;color:#2259c7;box-shadow:0 1px 3px #142f4912}.mode-tabs button:hover{color:#1a4ca6}#stage{position:absolute;inset:0}#stage>canvas{position:absolute;inset:0;display:block;width:100%;height:100%;pointer-events:none}#viewports{position:absolute;inset:155px 18px 110px;display:flex;z-index:1;min-width:0;min-height:0}.viewport{position:relative;min-width:0;flex:1;touch-action:none;overflow:hidden;outline:none;cursor:grab}.viewport:active{cursor:grabbing}.viewport[hidden]{display:none!important}.compare #view-right{border-left:1px solid #d6e3f0}.view-caption{position:absolute;top:10px;left:12px;font-size:11px;color:#5f7995;pointer-events:none;z-index:2}.view-caption strong{color:#22445f;margin-right:7px}.view-caption:empty{display:none}.annotation-layer{position:absolute;inset:0;pointer-events:none;overflow:hidden}.model-label{position:absolute;transform:translate(-50%,-50%);font-size:11px;padding:4px 7px;border-radius:5px;border:1px solid #d8c193;background:#ffffffed;color:var(--gold);white-space:nowrap;box-shadow:0 1px 4px #152f4910}.model-label.purple{color:#8062b2;border-color:#d7caeb}.model-label.blue{color:#2b68b5;border-color:#bed2ec}.stage-footer{position:absolute;left:25px;right:25px;bottom:19px;display:flex;justify-content:space-between;align-items:center;gap:10px;z-index:3}#legend{display:flex;flex-wrap:wrap;gap:11px;font-size:10px;color:#536f8d;max-width:220px}#legend span{display:flex;align-items:center;gap:6px}#legend i{width:10px;height:10px;border-radius:50%;background:var(--color);border:1px solid #142f491c}.view-actions{display:flex;gap:5px}.view-actions button{font-size:10px;padding:7px 9px}#stage-hint{position:absolute;bottom:66px;left:50%;transform:translateX(-50%);margin:0;color:#7188a1;font-size:10px;line-height:1.6;text-align:center;width:max-content;max-width:90%;padding:6px 12px;border:1px solid #d6e3f1;border-radius:7px;background:#ffffffcc;pointer-events:none;z-index:2}#inspector{overflow:auto;padding:24px 22px;border-left:1px solid var(--line);scrollbar-width:thin}.inspector-heading{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line);padding-bottom:17px;margin-bottom:20px;font-size:13px}.inspector-heading>span{font-size:9px;color:var(--muted);white-space:nowrap}.inspector-heading i{display:inline-block;width:5px;height:5px;background:#3faaa0;border-radius:50%;vertical-align:middle}#panel-body{font-size:12px}.label{display:block;font-size:10px;color:var(--muted);margin:0 0 8px}select{width:100%;padding:9px;border:1px solid var(--line);border-radius:6px;color:#355775;background:#fff;font-size:12px}.shape-result{margin:16px 0 17px;padding:17px 15px;background:#edf3ff;border-left:3px solid #6b95f4}.shape-result .kicker{font-size:10px;color:#6a85a8;margin-bottom:7px}.shape-result strong{font-size:25px;font-weight:600;color:#245ac0;display:block}.shape-result small{display:block;color:#6d85a2;font-family:Cambria,serif;font-size:14px;margin-top:6px}.metric{display:flex;justify-content:space-between;gap:12px;align-items:center;padding:8px 0;font-size:11px}.metric span{color:#73879c}.metric strong{font-weight:500;text-align:right}.section{border-top:1px solid var(--line);margin-top:18px;padding-top:17px}.section h2{font-size:12px;margin:0 0 12px;font-weight:600}.note{font-size:11px;line-height:1.9;color:#476987;margin:9px 0}.note.emphasis{background:#f3f7fd;border-left:2px solid #a8c1e8;padding:10px 11px}.subtle{font-size:10px;line-height:1.85;color:var(--muted);margin:8px 0}.toggle{display:flex;align-items:center;gap:8px;font-size:11px;margin:10px 0;line-height:1.6}.toggle input{accent-color:#2563eb;width:15px;height:15px;margin:0;flex:none}.segmented{display:flex;gap:5px}.segmented button{flex:1;font-size:11px;padding:8px}.control-row{display:flex;gap:7px;align-items:center;margin:11px 0}.control-row select{flex:1}.control-row button{flex:none}input[type=range]{width:100%;accent-color:#2563eb}.step{padding:10px 0;border-bottom:1px dashed #e1e8f1;font-size:11px;line-height:1.8}.step span{display:block;color:var(--muted);font-size:10px}.step strong{font-weight:500}.step.pending{color:#a6b2c0}.step.pending strong{font-weight:400}.button-row{display:flex;gap:7px;margin-top:13px}.button-row button{flex:1}.pill-row{display:flex;flex-wrap:wrap;gap:5px;margin:10px 0}.pill-row button{font-size:10px;padding:6px 8px}.angle-readout{padding:11px 12px;background:#fff8e9;border-left:2px solid #d4b267;margin:12px 0;color:#956722;font-size:12px;line-height:1.7}.angle-readout strong{font-family:Cambria,serif;font-size:21px}.pick-progress{font-size:10px;color:var(--muted);line-height:1.8}.quiz-question{font-size:13px;line-height:1.9;margin:12px 0}.quiz-answers{display:grid;grid-template-columns:1fr 1fr;gap:7px}.quiz-answers button{text-align:center;min-height:42px}.quiz-answers button.correct{border-color:#65ac9a;background:#edf8f5;color:#247e68}.quiz-answers button.wrong{border-color:#d8a0a0;background:#fff2f2;color:#b14d4d}.quiz-feedback{line-height:1.9;font-size:11px;padding:11px;background:#f1f6fc;margin-top:12px;border-radius:6px}.score{font-size:10px;color:var(--muted)}.builder-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}.builder-grid label{color:var(--muted);font-size:10px}.builder-grid select{margin-top:8px}.measurement-selects{display:grid;grid-template-columns:1fr 1fr 1fr;gap:4px;margin:9px 0}.measurement-selects select{font-size:10px;padding:7px 3px}.hidden-answers .answer{visibility:hidden!important}.hidden-answers .quiz-feedback{display:none}footer{height:29px;padding:0 22px;border-top:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:12px;font-size:9px;color:#7a8ca1;background:#fff}#toast{position:absolute;left:50%;top:165px;transform:translateX(-50%);padding:10px 15px;border-radius:6px;background:#142f49;color:#fff;font-size:11px;line-height:1.6;z-index:5;pointer-events:none;opacity:0;transition:opacity .15s}#toast.show{opacity:1}#webgl-error{position:absolute;left:12%;right:12%;top:42%;padding:20px;border:1px solid #bed0e5;background:white;font-size:13px;line-height:1.9;z-index:2}dialog{width:min(620px,calc(100% - 32px));max-height:85dvh;border:1px solid var(--line);border-radius:12px;padding:25px;color:var(--ink);line-height:1.9}dialog::backdrop{background:#142f4966}.dialog-head{display:flex;justify-content:space-between;align-items:center;gap:15px}.dialog-head h2{font-size:17px;margin:0}dialog p{font-size:12px}dialog a{color:#2563eb}#shade{display:none}.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}.empty{color:var(--muted);font-size:11px;line-height:1.9;padding:15px 0}
@media(min-width:1600px){main{grid-template-columns:235px minmax(0,1fr) 365px}#inspector{padding:28px}.model-button{padding:12px 9px}.workspace-heading{top:32px}}
@media(max-width:1150px){main{grid-template-columns:minmax(0,1fr) 315px}#library{position:fixed;left:0;top:76px;bottom:29px;width:225px;z-index:9;transform:translateX(-100%);transition:transform .18s}.mobile#library-toggle{display:block}body.library-open #library{transform:none}body.library-open #shade{display:block;position:fixed;inset:76px 0 29px;background:#142f4955;z-index:8}.workspace-heading{left:23px;right:23px}.mode-tabs{left:23px}}
@media(max-width:760px),(max-width:1150px) and (max-height:540px){header{height:62px;padding:0 12px}.brand{font-size:18px;gap:7px}.brand svg{width:27px;height:30px}.brand small{font-size:8px;letter-spacing:0}.header-actions{gap:5px}.header-actions button{padding:7px 8px;font-size:10px}.mobile{display:block}#fullscreen{display:none}#export{font-size:0}#export:after{content:'导图';font-size:10px}#hide-answers{font-size:0}#hide-answers:after{content:'答案';font-size:10px}main{display:block;height:calc(100dvh - 88px)}.workspace{height:100%}#library{top:62px;bottom:26px}#inspector{position:fixed;right:0;top:62px;bottom:26px;width:min(330px,88vw);transform:translateX(100%);transition:transform .18s;z-index:9;padding:21px 18px}.panel-open #inspector{transform:none}body.panel-open #shade,body.library-open #shade{display:block;position:fixed;inset:62px 0 26px;z-index:8;background:#142f4955}.workspace-heading{top:21px;left:17px;right:17px}.workspace-heading p{font-size:10px}h1{font-size:25px}h1 small{font-size:17px}#model-badge{font-size:9px;padding:7px 8px;max-width:105px}.mode-tabs{top:96px;left:17px;right:17px;justify-content:space-between}.mode-tabs button{font-size:10px;padding:8px 7px;flex:1}#viewports{inset:143px 8px 112px}.compare #viewports{flex-direction:column}.compare #view-right{border-left:0;border-top:1px solid #d6e3f0}.view-caption{top:7px;left:10px;font-size:10px}.stage-footer{left:15px;right:15px;bottom:14px;align-items:end}.view-actions{gap:4px}.view-actions button{padding:7px;font-size:9px}#legend{font-size:9px;max-width:110px;gap:7px}#stage-hint{bottom:67px;font-size:9px;max-width:90%}footer{height:26px;padding:0 12px;font-size:8px}footer span:last-child{display:none}#toast{top:145px;max-width:90%;width:max-content}.view-caption small{font-size:9px}}
@media(max-height:540px){header{height:49px}.brand small{display:none}main{height:calc(100dvh - 72px)}footer{height:23px}#library,#inspector{top:49px;bottom:23px}body.panel-open #shade,body.library-open #shade{inset:49px 0 23px}.workspace-heading{top:10px}h1{font-size:21px}.workspace-heading p{margin-bottom:3px;font-size:9px}.mode-tabs{top:64px;right:auto}.mode-tabs button{padding:6px 9px}#viewports{inset:101px 10px 65px}.compare #viewports{flex-direction:row}.compare #view-right{border-left:1px solid #d6e3f0;border-top:0}.stage-footer{bottom:9px}#stage-hint{bottom:42px;padding:4px 8px;font-size:9px}.view-caption{top:3px}#toast{top:95px}}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}
.mode-tabs button{white-space:nowrap}
@media(max-width:380px){header{gap:8px}.brand{font-size:16px;gap:6px}.brand svg{width:23px}.brand small{display:none}.header-actions{gap:4px}.header-actions button{padding:7px 6px}.workspace-heading{left:13px;right:13px}.mode-tabs{left:13px;right:13px}.mode-tabs button{padding:8px 5px;font-size:9px}.view-actions button{padding:6px}.stage-footer{left:12px;right:12px}#legend{max-width:90px}}

.molecule-facts{margin:16px 0}.fact-item{padding:13px 0;border-bottom:1px solid var(--line)}.fact-item h3{font-size:11px;font-weight:500;color:#657f9c;margin:0}.fact-heading{display:flex;justify-content:space-between;align-items:baseline;gap:12px}.fact-heading .fact-value{font-size:16px;font-weight:500;color:#245ac0;text-align:right}.fact-item.shape-result{padding:15px;margin:0 0 2px;border-bottom:0}.fact-item.shape-result h3{margin-bottom:8px}.fact-item.shape-result strong{font-size:23px}.count-inputs,.count-explanation,.count-breakdown,.count-conclusion{font-size:11px;line-height:1.85;margin:8px 0 0;color:#486987;overflow-wrap:anywhere}.count-equation{font:15px/1.8 Cambria,'Microsoft YaHei',serif;color:#245ac0;margin:7px 0 0;padding:6px 8px;background:#f1f6ff;border-left:2px solid #9ebbef;overflow-wrap:anywhere}.count-conclusion{color:#2c5c9a}.lone-equation{font-size:14px}.count-note{font-size:9px;margin-bottom:0}.step-detail{font-size:11px;line-height:1.85;color:#3c6084;margin-top:4px}.step.pending .step-detail{color:#a6b2c0}.step-detail .count-equation{font-size:13px}.count-process .subtle{margin-top:7px}