:root{--bg:#f5f6f8;--ink:#202b37;--muted:#77818d;--line:#e4e8ed;--green:#276753;--light:#e9f1eb}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.75 "Segoe UI","Microsoft YaHei",sans-serif}button,input,textarea,select{font:inherit}button,a,label.import{touch-action:manipulation}button{cursor:pointer;border:1px solid var(--line);border-radius:9px;padding:9px 16px;background:white;color:var(--ink)}button:hover{border-color:var(--green);color:var(--green)}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid #d9ac58;outline-offset:3px}aside{position:fixed;inset:0 auto 0 0;width:246px;background:#fff;border-right:1px solid var(--line);padding:35px 25px;display:flex;flex-direction:column}.brand{display:flex;gap:12px;align-items:center;font-size:24px;color:var(--green);text-decoration:none;font-weight:700}.brand span{font-size:18px}.brand small{display:block;font-size:9px;letter-spacing:2px;color:var(--muted)}.year{font-size:11px;color:var(--muted);margin:24px 0 30px}nav{display:grid;gap:10px}nav button{text-align:left;border:0;background:none;padding:13px 17px}nav button.active{background:var(--light);color:var(--green);font-weight:600}.side-bottom{margin-top:auto;font-size:13px;color:var(--muted)}.side-bottom button,.import{display:block;background:none;border:0;padding:6px 0;font-size:12px;cursor:pointer}.import input{display:none}.side-bottom small{display:block;margin-top:16px;font-size:10px}main{margin-left:246px;padding:0 48px;max-width:1600px}header{height:83px;display:flex;align-items:center;justify-content:space-between;font-size:12px;color:var(--muted)}header b{color:var(--ink);font-weight:500}.badge{border:1px solid var(--line);border-radius:30px;padding:5px 12px;font-size:10px;letter-spacing:1px}.hero{position:relative;display:flex;justify-content:space-between;overflow:hidden;border:1px solid #dbe4df;border-radius:18px;background:#eaf0ea;padding:37px 42px;min-height:310px}.eyebrow{font-size:10px;letter-spacing:3px;color:var(--green)}h1{font-size:37px;line-height:1.4;font-weight:650;letter-spacing:1px;margin:14px 0}p{margin:8px 0;color:var(--muted)}.hero p{font-size:12px}.primary{background:var(--green);color:white;border-color:var(--green)}.primary:hover{background:#1a4c3d;color:white}.hero button{margin-top:17px;font-size:12px}.orbit{position:relative;width:37%;min-height:230px;background-image:radial-gradient(#adc0b466 1px,transparent 1px);background-size:18px 18px}.orbit-ring{position:absolute;width:230px;height:130px;border:1px solid #9eb9a9;border-radius:50%;transform:rotate(-30deg);left:15%;top:60px}.second{transform:rotate(55deg)}.ball{position:absolute;left:45%;top:70px;font-size:76px;filter:drop-shadow(12px 20px 12px #234b3522)}.formula{position:absolute;right:0;top:17px;font:italic 20px Georgia;color:var(--green)}.orbit-label{position:absolute;bottom:5px;left:22%;font-size:10px;letter-spacing:3px;color:#77917d}.stats{display:grid;grid-template-columns:1fr 1fr 1.5fr;gap:18px;margin:25px 0 35px}.stats>div,.card{background:white;border:1px solid var(--line);border-radius:13px;padding:23px}.stats span{color:var(--muted);font-size:12px}.stats strong{display:block;font-size:30px;font-weight:600;margin-top:5px}.stats small{font-size:13px;color:var(--muted);font-weight:400}.stats .text-stat{font-size:18px;margin:14px 0}.stats p{font-size:11px}.track{height:4px;background:#edf0ed;border-radius:5px;margin-top:13px;overflow:hidden}.track i{display:block;height:100%;background:var(--green)}h2{font-size:22px;margin:0}h3{font-size:17px;margin:0 0 12px}h4{font-size:14px;margin:15px 0 5px}.section-head{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-bottom:20px}.section-head p{font-size:12px}.layout{display:grid;grid-template-columns:240px 1fr;gap:22px}.week-list{max-height:860px;overflow:auto;padding-right:8px}.week-list button{width:100%;display:block;text-align:left;padding:13px;margin-bottom:8px;border-radius:10px}.week-list button.selected{border-color:var(--green);background:var(--light)}.week-list small{display:block;color:var(--muted);font-size:10px}.week-list b{font-size:12px;font-weight:500}.tag{font-size:10px;color:var(--green);background:var(--light);padding:4px 8px;border-radius:5px}.lesson-head{display:flex;justify-content:space-between;gap:15px;margin-bottom:20px}.lesson h2{margin:10px 0 4px}.lesson p,.lesson li{font-size:13px;color:#56616c}.lesson .formula-box{background:#f5f7f8;border-left:3px solid #a5b8ac;padding:16px;font:20px/1.6 Georgia,"Microsoft YaHei";margin:18px 0}.task{display:flex;align-items:flex-start;gap:12px;border-top:1px solid var(--line);padding:12px 0;font-size:13px}.task input{accent-color:var(--green);margin-top:6px;width:17px;height:17px}.task small{display:block;color:var(--muted)}details{border:1px solid var(--line);border-radius:8px;padding:12px 15px;margin-top:12px;font-size:13px}summary{cursor:pointer;color:var(--green)}textarea{width:100%;min-height:110px;resize:vertical;background:#fafbfc;border:1px solid var(--line);border-radius:8px;padding:13px;font-size:13px}input[type=search],select{max-width:100%;border:1px solid var(--line);border-radius:8px;background:white;padding:8px 12px;font-size:12px}.tools{display:flex;gap:8px;flex-wrap:wrap}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.phase button{display:block;width:100%;text-align:left;margin-top:8px;font-size:12px}.phase h3{margin-top:12px}.note{white-space:pre-wrap;overflow-wrap:anywhere}.lab-controls{display:flex;gap:28px;flex-wrap:wrap;margin:20px 0}.lab-controls label{flex:1;min-width:160px}.lab-controls input{width:100%;accent-color:var(--green)}svg{width:100%;max-height:370px}.callout{background:#f8f3e8;border-radius:8px;padding:12px 15px;color:#877342!important;font-size:12px!important}footer{padding:40px 0;color:#949ca5;font-size:10px}#toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);background:var(--green);color:white;padding:10px 22px;border-radius:10px;display:none;z-index:10}.lesson-actions{display:flex;justify-content:space-between;margin-top:20px}button:disabled{opacity:.4;cursor:default}@media(min-width:1450px){main{padding-left:65px;padding-right:65px}}@media(max-width:1100px){aside{width:210px;padding:25px 18px}main{margin-left:210px;padding:0 25px}.layout{grid-template-columns:190px 1fr}.grid{grid-template-columns:repeat(2,1fr)}.orbit{width:35%}.orbit-ring{left:0;width:180px}.ball{left:30%}.stats{gap:10px}.stats>div{padding:17px}.hero{padding:30px}.stats .text-stat{font-size:15px}}@media(max-width:760px){aside{position:static;width:auto;padding:18px;border-right:0}.year,.side-bottom{display:none}nav{display:flex;margin-top:16px;gap:4px;overflow:auto}nav button{white-space:nowrap;padding:8px 10px;font-size:12px}.brand{font-size:20px}main{margin:0;padding:0 16px}header{height:58px}.badge{font-size:8px}.hero{padding:26px;min-height:270px}h1{font-size:29px}.orbit{display:none}.stats{grid-template-columns:1fr 1fr;margin:16px 0 26px}.stats>div:last-child{grid-column:1/-1}.stats .text-stat{margin:5px 0}.layout{display:block}.week-list{max-height:200px;display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-bottom:18px}.week-list button{margin:0}.section-head{align-items:flex-start;flex-direction:column}.grid{grid-template-columns:1fr}.card{padding:20px}.lesson-head{flex-wrap:wrap}.side-bottom{display:none}}@media print{aside,header,.hero,.stats,.week-list,.tools,footer,.lesson-actions{display:none}main{margin:0;padding:0}.layout{display:block}.card{border:0}details>*{display:block}}
.lesson-head{align-items:flex-start}
.formula-guide{background:#f7faf8;margin:16px 0}.formula-guide>summary{font-weight:600}.formula-guide-row{border-top:1px solid var(--line);padding:15px 0;min-width:0}.formula-guide-title{display:flex;align-items:flex-start;justify-content:space-between;gap:12px;flex-wrap:wrap;font-size:13px}.formula-guide-title a{font-size:12px;color:var(--green);text-decoration:none;border:1px solid #ceded3;background:white;border-radius:6px;padding:5px 9px;white-space:nowrap}.formula-guide-title a:hover{text-decoration:underline;background:var(--light)}.formula-guide-row code{display:block;white-space:normal;overflow-wrap:anywhere;font:14px/1.7 Consolas,monospace;margin:9px 0;color:#2a5544}.lesson .formula-guide-row p,.formula-guide-row p{font-size:13px;color:#56616c;line-height:1.7}.lesson .formula-guide-disclaimer,.formula-guide-disclaimer{font-size:11px;color:var(--muted);margin:12px 0}.formula-guide-row:last-child{padding-bottom:0}
.session-card{border:1px solid var(--line);border-radius:12px;padding:20px;margin:18px 0;background:#fff}.session-heading{display:flex;align-items:center;justify-content:space-between;gap:10px;flex-wrap:wrap;margin-bottom:14px}.session-check{font-size:12px;display:flex;align-items:center;gap:7px;cursor:pointer}.session-check input{width:17px;height:17px;accent-color:var(--green)}.session-card h3{font-size:17px}.session-steps{list-style:none;padding:0;margin:18px 0}.session-steps li{display:flex;align-items:flex-start;gap:12px;padding:12px 0;border-top:1px solid #edf0ed}.session-steps li>span{flex:0 0 58px;color:var(--green);background:var(--light);border-radius:5px;text-align:center;font-size:11px;padding:3px}.session-steps li>div{flex:1;min-width:0}.session-question{padding:12px 14px;margin:10px 0;background:#f7f9f8;border-radius:8px}.session-question details{background:white}.lesson .session-deliver{background:#edf4ef;padding:12px;border-radius:8px;color:#3d6652}.lesson .session-note-hint{font-size:11px;color:#89938c}@media(max-width:760px){.session-card{padding:14px}.session-steps li{gap:9px}.session-steps li>span{flex-basis:50px}}@media print{.session-card{break-inside:auto}.session-heading,.session-question{break-inside:avoid}.session-note-hint{display:none}}
/* Click-to-open navigation drawer */
.nav-toggle{position:fixed;top:18px;left:16px;z-index:103;min-height:44px;background:var(--green);color:white;border-color:var(--green);box-shadow:0 3px 14px #203b2520}.nav-toggle:hover{background:#1a4c3d;color:white}
#site-sidebar{position:fixed;inset:0 auto 0 0;width:min(280px,85vw);height:100vh;height:100dvh;padding:82px 24px 24px;z-index:102;overflow-y:auto;transform:translateX(-100%);visibility:hidden;transition:transform .22s ease,visibility .22s;box-shadow:8px 0 30px #203b2518;display:flex;flex-direction:column}
.nav-open #site-sidebar{transform:translateX(0);visibility:visible}
#site-sidebar nav{display:grid;gap:10px;overflow:visible;margin-top:0}#site-sidebar nav button{white-space:normal;padding:13px 17px}#site-sidebar .year{display:block;margin:24px 0 30px}#site-sidebar .side-bottom{display:block;padding-top:28px;margin-top:auto}
.nav-backdrop{position:fixed;inset:0;background:#15271d40;z-index:101}.nav-backdrop[hidden]{display:none}
main{margin-left:auto;margin-right:auto}main>header{padding-left:88px}
@media(max-width:760px){.nav-toggle{top:10px;left:12px;padding:8px 12px}main>header{height:105px;padding:62px 0 10px;gap:8px}#site-sidebar{padding-top:76px}}
@media(prefers-reduced-motion:reduce){#site-sidebar{transition:none}}
@media print{#site-sidebar,.nav-toggle,.nav-backdrop{display:none!important}main{margin:0}}
.experiment-zone{margin:28px 0;padding:20px;background:#eef5f1;border-radius:12px}.experiment-card{background:white;border:1px solid #d9e5dd;padding:20px;border-radius:10px;margin-top:16px}.experiment-card h4{font-size:20px;margin:12px 0}.experiment-card li{margin:10px 0}.experiment-card ol{padding-left:22px}.lesson .experiment-prompt{font-size:15px;color:#285d47;background:#f1f7f3;padding:14px;border-left:3px solid #57856b}.experiment-predict-label{font-size:12px;color:#637a6a}.experiment-prediction{min-height:80px;margin-top:8px}.lesson .experiment-safety{font-size:12px;color:#806d47;background:#faf6ed;padding:10px;border-radius:6px}.experiment-card button{white-space:normal;text-align:left;font-size:12px}@media(max-width:760px){.experiment-zone{padding:12px}.experiment-card{padding:14px}}
/* Experiment-led workspace */
.hero{min-height:190px;padding:24px 32px}.hero h1{font-size:30px}.hero h1 br{display:none}.hero .orbit{min-height:150px}.hero .orbit-ring{top:15px;height:100px}.hero .ball{font-size:58px;top:22px}.hero .orbit-label{bottom:0}.hero button{margin-top:10px}.stats{margin:16px 0;gap:14px}.stats>div{padding:14px 20px}.stats strong{font-size:24px}.stats .text-stat{margin:6px 0}.upgrade-note{margin:12px 0 26px}.experiment-layout{display:block}.experiment-picker{margin:0 0 18px;background:white;padding:15px 20px}.experiment-picker>summary{font-weight:600}.experiment-picker>summary span{font-weight:400;font-size:11px;margin-left:12px;color:var(--muted)}.experiment-picker .week-list{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:9px;max-height:370px;margin-top:18px}.experiment-picker .week-list button{margin:0}.experiment-flow{display:flex;gap:10px;flex-wrap:wrap;margin:12px 0 20px}.experiment-flow a{background:var(--light);color:var(--green);font-size:12px;text-decoration:none;padding:9px 14px;border-radius:7px}.experiment-flow a:hover{background:#d9e9df}.experiment-zone{margin:0;padding:24px}.experiment-notebook{margin:22px 0;padding:22px;background:#f8f6f0;border:1px solid #e8e1d3;border-radius:12px}.experiment-notebook textarea{min-height:190px;background:white}.study-drawer{margin:18px 0;padding:20px;background:#fafcfb}.study-drawer>summary{font-size:16px;font-weight:600}.study-drawer[open]>summary{margin-bottom:22px}#experiment-start,#experiment-notes,#experiment-theory,#experiment-study{scroll-margin-top:78px}.lesson{padding:28px}.experiment-card h4{font-size:24px}.experiment-card{padding:24px}.experiment-card .experiment-prompt{font-size:18px}.experiment-card>ol{counter-reset:experiment-step;list-style:none;padding:0}.experiment-card>ol>li{counter-increment:experiment-step;position:relative;padding:12px 12px 12px 50px;border:1px solid var(--line);border-radius:8px}.experiment-card>ol>li:before{content:counter(experiment-step);position:absolute;left:14px;top:12px;background:var(--light);color:var(--green);border-radius:50%;width:25px;text-align:center}.experiment-card button{background:var(--green);color:white}
@media(max-width:760px){.hero{min-height:0;padding:20px}.hero h1{font-size:26px}.hero h1 br{display:block}.stats>div:last-child{display:none}.stats strong{font-size:23px}.experiment-picker .week-list{grid-template-columns:1fr 1fr}.lesson{padding:16px}.experiment-zone,.experiment-card,.experiment-notebook,.study-drawer{padding:14px}.experiment-card h4{font-size:21px}.experiment-card .experiment-prompt{font-size:16px}.experiment-flow{display:grid;grid-template-columns:1fr 1fr;gap:6px}.experiment-flow a{padding:9px;font-size:11px}.experiment-picker>summary span{display:block;margin-left:18px}}
@media print{.experiment-picker,.experiment-flow{display:none}.study-drawer>*,.study-drawer::details-content{display:block;content-visibility:visible}}
/* First screen opens directly on the experiment workspace. */
.site-overview{margin-top:28px;background:white}.site-overview>summary{font-weight:600}.site-overview[open]>summary{margin-bottom:20px}main>header{height:72px}.experiment-picker{margin-bottom:12px}.lesson-head{margin-bottom:12px}.experiment-zone>p{font-size:12px}.experiment-zone{padding:16px}.experiment-card{margin-top:12px}.experiment-flow{margin:10px 0 14px}.experiment-card h4{margin-top:10px}
@media(max-width:760px){main>header{height:70px;padding:12px 0 12px 84px}main>header .badge{display:none}#content>.section-head{gap:8px;margin-bottom:12px}#content>.section-head h2{font-size:21px}#content>.section-head p{margin:2px 0}#content .tools{width:100%;display:grid;grid-template-columns:minmax(0,1fr) 115px;gap:6px}#content .tools input{min-width:0;width:100%}.experiment-picker{padding:10px 12px}.experiment-picker>summary span{display:none}.lesson-head h2{font-size:23px}.lesson-head>button{padding:5px 10px;font-size:11px}.experiment-zone{padding:12px}.experiment-zone>p{font-size:11px;line-height:1.6}.experiment-card{padding:12px}.experiment-flow{gap:4px}.experiment-flow a{padding:7px 5px}}
.experiment-figure{margin:20px 0;border:1px solid #dce7df;border-radius:12px;padding:12px;background:#f5f9f6}.experiment-figure svg{display:block;width:100%;height:auto;max-height:none}.experiment-figure svg text{font:14px "Microsoft YaHei",sans-serif;fill:#305342}.experiment-figure figcaption{font-size:11px;color:#738578;margin-top:8px}.experiment-card h5{font-size:16px;color:var(--green);margin:22px 0 9px}.experiment-card .detailed-steps{list-style:none;padding:0}.experiment-card .detailed-steps li{padding:16px;border:1px solid var(--line);border-radius:9px;margin:12px 0}.experiment-card .detailed-steps li:before{display:none}.detailed-steps b{color:var(--green);font-size:13px}.detailed-steps p{margin-bottom:0}.lesson .experiment-pitfall{background:#fcf5e9;padding:14px;border-radius:8px;color:#79633c}.experiment-duration{font-size:12px!important}@media(max-width:760px){.experiment-figure{padding:4px;margin:16px -4px}.experiment-figure svg{min-width:0}.experiment-figure figcaption{padding:6px}.experiment-card .detailed-steps li{padding:12px}}@media print{.experiment-figure{break-inside:avoid}}
.diagram-enlarge{margin-bottom:12px}.experiment-table-scroll{overflow-x:auto;max-width:100%;margin:14px 0}.experiment-table{border-collapse:collapse;min-width:560px;width:100%;font-size:12px}.experiment-table caption{text-align:left;color:var(--green);padding:10px 0}.experiment-table th,.experiment-table td{border:1px solid #d9e5dd;padding:12px;text-align:left}.experiment-table th{background:#eef5f1}.experiment-table td{color:#8a968e}#diagram-dialog{width:min(960px,94vw);max-width:94vw;max-height:90dvh;border:1px solid #cbdcd0;border-radius:14px;padding:22px;color:var(--ink)}#diagram-dialog::backdrop{background:#14291fcc}.diagram-dialog-head{display:flex;align-items:center;justify-content:space-between;gap:15px}.diagram-dialog-head h3{margin:0}.diagram-dialog-head button{white-space:nowrap}.diagram-zoom-scroll{overflow-x:auto}.diagram-zoom-scroll .experiment-figure{min-width:650px}.diagram-zoom-scroll svg text{font-size:15px}#diagram-dialog>p{font-size:12px}@media(max-width:760px){#diagram-dialog{padding:14px}.diagram-dialog-head h3{font-size:15px}.diagram-dialog-head button{padding:7px 10px}}@media print{.diagram-enlarge,#diagram-dialog{display:none}.experiment-table{min-width:0}.experiment-table-scroll{overflow:visible}}