@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700;800&family=Noto+Sans+TC:wght@400;500;600;700;800&display=swap');
:root{font-family:'DM Sans','Noto Sans TC',system-ui,sans-serif;color:#20242b;background:#f5f6f7;font-size:16px;line-height:1.55;font-synthesis:none}*{box-sizing:border-box}body{margin:0}button,input,select{font:inherit}button{cursor:pointer}a{color:inherit;text-decoration:none}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #ff8a2a;outline-offset:2px}.shell{display:grid;grid-template-columns:264px minmax(0,1fr);min-height:100vh}.sidebar{background:#171b22;color:#f7f8fa;display:flex;flex-direction:column;padding:26px 15px;position:sticky;top:0;height:100vh}.brand{display:flex;align-items:center;gap:12px;padding:8px 11px 30px}.brand img{background:#fff;border-radius:13px;padding:5px}.brand span{display:grid;line-height:1.15}.brand strong{font-size:1.32rem;letter-spacing:-.04em}.brand small{font-size:.85rem;color:#aab1bd;margin-top:5px}.sidebar nav{display:grid;gap:4px}.nav-link{display:flex;align-items:center;gap:13px;padding:12px 14px;color:#bdc3cc;border-radius:12px;font-size:.96rem;font-weight:600;transition:.18s}.nav-link:hover{background:#272d36;color:white}.nav-link.active{background:#34383e;color:#fff}.nav-link.active .ico{color:#ff810c}.ico{width:22px;text-align:center;font-size:1.15rem}.sidebar-foot{margin-top:auto;border-top:1px solid #343943;padding:20px 12px 0;color:#9ba3ad;font-size:.73rem;display:flex;gap:9px;align-items:center}.version-dot{width:7px;height:7px;background:#ff7900;border-radius:50%}main{padding:32px clamp(22px,4vw,68px) 80px;min-width:0}.page{max-width:1230px;margin:auto}.topline{display:flex;align-items:center;justify-content:space-between;gap:16px;color:#78818e;font-weight:700;font-size:.78rem;letter-spacing:.12em;text-transform:uppercase;margin:0 0 16px}.topline .date{letter-spacing:0;font-weight:500}.page-title{font-size:clamp(1.8rem,3vw,2.6rem);line-height:1.2;letter-spacing:-.035em;margin:0 0 9px}.lead{color:#65707c;margin:0 0 27px;max-width:760px}.section-title{font-size:1.26rem;letter-spacing:-.02em;margin:32px 0 14px}.grid{display:grid;gap:16px}.grid.two{grid-template-columns:repeat(2,minmax(0,1fr))}.grid.three{grid-template-columns:repeat(3,minmax(0,1fr))}.card{background:#fff;border:1px solid #e6e8eb;border-radius:20px;padding:23px;box-shadow:0 8px 32px rgba(28,34,40,.025)}.card h2,.card h3{margin:0 0 9px;line-height:1.3}.muted{color:#68727d}.small{font-size:.85rem}.eyebrow{color:#eb7000;font-size:.76rem;letter-spacing:.13em;font-weight:800}.hero{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(290px,.75fr);gap:18px}.hero-panel{background:#171b22;color:#fff;border-radius:24px;padding:clamp(25px,3vw,43px);position:relative;overflow:hidden;min-height:350px}.hero-panel:after{content:'1';position:absolute;right:12px;bottom:-100px;font-weight:800;font-size:380px;line-height:1;color:#fff;opacity:.035;pointer-events:none}.hero-panel h2{font-size:clamp(2rem,3.2vw,3.25rem);line-height:1.15;letter-spacing:-.055em;max-width:560px;margin:16px 0}.hero-panel p{color:#bac1ca;max-width:480px}.hero-panel .accent{color:#ff850e}.hero-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:30px}.btn{border:0;border-radius:11px;background:#ff7900;color:#171b22;font-weight:800;padding:11px 17px;min-height:45px;display:inline-flex;align-items:center;justify-content:center;gap:7px}.btn:hover{background:#ff942e}.btn.secondary{background:#f0f2f4;color:#222932}.btn.secondary:hover{background:#e6e9ec}.btn.dark{background:#303640;color:#fff}.btn.ghost{background:transparent;border:1px solid #d7dce1;color:#28313b}.btn.small-btn{font-size:.84rem;padding:8px 11px;min-height:36px}.btn:disabled{opacity:.45;cursor:not-allowed}.kpi{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.kpi .card{padding:21px}.kpi b{display:block;font-size:1.65rem;letter-spacing:-.04em}.kpi span{font-size:.82rem;color:#69727d}.metric{font-size:clamp(2rem,3vw,3rem);font-weight:800;line-height:1.15;letter-spacing:-.05em;color:#e86d00;margin:10px 0}.metric small{font-size:1rem;letter-spacing:0;color:#53606c}.field{display:grid;gap:7px;font-weight:700;font-size:.9rem;margin:0 0 17px}.field input,.field select,.field textarea{width:100%;border:1px solid #d8dde2;border-radius:10px;background:#fff;color:#222;padding:11px 13px;min-height:47px}.field input[type=range]{padding:0;accent-color:#ff7900;min-height:30px}.field-note{font-size:.82rem;color:#68727d;font-weight:400}.segmented,.chips{display:flex;gap:8px;flex-wrap:wrap;margin:0 0 20px}.segmented button,.chips button{border:1px solid #dfe3e7;background:#fff;border-radius:10px;padding:9px 15px;color:#56616d;font-weight:700}.segmented button[aria-pressed=true],.chips button[aria-pressed=true]{background:#20252c;border-color:#20252c;color:#fff}.result{background:#fff8f2;border:1px solid #ffddc2;border-radius:16px;padding:18px;margin:16px 0}.formula{font-family:'DM Sans',system-ui,sans-serif;color:#37414b;background:#f4f5f6;padding:12px 14px;border-radius:9px;font-size:.94rem;overflow-wrap:anywhere}.choice{display:block;width:100%;text-align:left;border:1px solid #dce1e5;background:#fff;border-radius:11px;padding:13px 15px;margin:8px 0}.choice:hover,.choice.selected{border-color:#fa800d;background:#fff8f1}.lesson-card,.resource-card{display:flex;flex-direction:column;gap:8px}.lesson-card .btn,.resource-card .btn{align-self:flex-start;margin-top:auto}.chapter{background:#fff;border:1px solid #e5e8eb;border-radius:20px;padding:21px;margin-bottom:14px}.chapter summary{cursor:pointer;font-weight:800;font-size:1.15rem}.chapter p{color:#68727d}.progress-track{height:8px;background:#e8eaed;border-radius:9px;overflow:hidden}.progress-track span{display:block;height:100%;background:#ff7900}.tags{display:flex;gap:7px;flex-wrap:wrap}.tag{display:inline-block;padding:4px 8px;border-radius:6px;background:#f1f2f3;color:#66717b;font-size:.75rem;font-weight:700}.tag.orange{background:#fff0df;color:#c25a00}.list-row{display:flex;align-items:center;justify-content:space-between;gap:15px;padding:15px 0;border-bottom:1px solid #e9ebed}.list-row:last-child{border:0}.list-row strong{display:block}.list-row .muted{font-size:.85rem}.empty{border:1px dashed #ccd2d8;border-radius:16px;padding:30px;text-align:center;color:#64707c}.notice{border-left:4px solid #ff7900;background:#fff7ef;padding:12px 16px;border-radius:0 10px 10px 0;color:#5f4937}.error{color:#a43d23;font-weight:700}.success{color:#267451;font-weight:700}.statusline{min-height:27px}.mobile-nav{display:none}#toast{position:fixed;bottom:24px;right:24px;background:#242b33;color:#fff;padding:11px 18px;border-radius:10px;box-shadow:0 10px 30px #0003;opacity:0;transform:translateY(12px);pointer-events:none;transition:.2s;z-index:20}#toast.show{opacity:1;transform:none}.plain-list{margin:0;padding-left:20px;color:#5f6b76}.plain-list li{margin:7px 0}.resource-tools{display:flex;gap:10px;align-items:end;flex-wrap:wrap}.resource-tools .field{min-width:220px;flex:1}.resource-card h3{font-size:1rem}.barline{display:flex;justify-content:space-between;align-items:center;gap:15px}.score-table{display:grid;grid-template-columns:120px 1fr 48px;align-items:center;gap:11px;margin:11px 0}.score-table .progress-track{height:10px}.tight{margin-top:0}.footer-note{font-size:.8rem;color:#838c96;margin-top:34px}.hidden{display:none!important}
@media(max-width:1050px){.shell{grid-template-columns:220px minmax(0,1fr)}.hero{grid-template-columns:1fr}.hero-panel{min-height:280px}.grid.three{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:760px){.shell{display:block}.sidebar{height:auto;position:relative;padding:11px 18px;background:#171b22}.brand{padding:0}.brand img{width:37px;height:37px}.brand strong{font-size:1.12rem}.sidebar nav,.sidebar-foot{display:none}main{padding:24px 16px 98px}.grid.two,.grid.three{grid-template-columns:1fr}.hero-panel{min-height:300px;padding:26px}.hero-panel:after{font-size:290px;bottom:-70px}.mobile-nav{display:flex;position:fixed;bottom:0;left:0;right:0;z-index:10;background:#fff;border-top:1px solid #e1e4e7;padding:5px 5px max(5px,env(safe-area-inset-bottom));justify-content:space-around;box-shadow:0 -6px 20px #1111}.mobile-nav .nav-link{display:grid;gap:0;place-items:center;color:#6a7480;font-size:.68rem;padding:5px 8px;border-radius:8px}.mobile-nav .nav-link.active{color:#e86f00;background:#fff3e8}.mobile-nav .ico{font-size:1.18rem}.topline{font-size:.7rem}.card{padding:18px}.kpi{grid-template-columns:repeat(2,1fr)}.kpi b{font-size:1.35rem}#toast{left:16px;right:16px;bottom:77px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
[hidden]{display:none!important}
.install-app{border:1px solid #8b929d;background:transparent;color:#fff;border-radius:8px;padding:7px 10px;font-weight:700;font-size:.8rem;white-space:nowrap}
.sidebar-foot{flex-wrap:wrap}.sidebar-foot .install-app{margin-top:10px;width:100%}
.sidebar-copyright{flex-basis:100%;font-size:.72rem;color:#aeb6c1}
.sidebar>.install-app{display:none}
.pwa-banner{position:fixed;z-index:30;left:50%;bottom:22px;transform:translateX(-50%);background:#20252c;color:#fff;box-shadow:0 10px 35px #0004;border-radius:12px;padding:11px 13px;display:flex;gap:12px;align-items:center;max-width:calc(100vw - 24px)}
.pwa-banner button{border:0;border-radius:7px;padding:8px 10px;background:#ff7900;color:#171b22;font-weight:700;white-space:nowrap}.pwa-banner button:last-child{background:#3b434c;color:#fff}
@media(max-width:760px){.sidebar{display:flex;flex-direction:row;align-items:center;justify-content:space-between}.sidebar>.install-app{display:block}.pwa-banner{bottom:76px;left:12px;right:12px;transform:none;justify-content:space-between;font-size:.83rem}.pwa-banner button{font-size:.78rem}}

/* Energy workbench visual system */
:root{--ink:#192028;--orange:#ef7200;--paper:#f5f5f1;--line:#dde1df}
body{background:var(--paper);color:var(--ink)}
.shell{grid-template-columns:248px minmax(0,1fr)}
.sidebar{background:#181d22;padding:26px 17px;border-right:1px solid #343a3e}
.brand{padding:6px 11px 27px}
.brand img{border-radius:11px}
.sidebar nav{gap:5px}
.nav-link{border-radius:10px;padding:11px 13px;font-size:.94rem}
.nav-link.active{background:#303840;box-shadow:inset 3px 0 var(--orange)}
.ico{width:24px;height:24px;display:inline-grid;place-items:center;flex:none}
.ico svg{display:block;width:20px;height:20px}
main{padding:34px clamp(24px,4.2vw,66px) 68px}
.page{max-width:1280px}
.topline{margin-bottom:12px;color:#8a7463;font-size:.72rem}
.page-title{font-size:clamp(2rem,3vw,2.72rem);letter-spacing:-.045em}
.lead{margin-bottom:23px;color:#5d6970}
.card{border:1px solid var(--line);border-radius:17px;box-shadow:0 4px 20px #27313b08;padding:22px}
.section-title{margin:32px 0 14px;padding-left:12px;border-left:3px solid var(--orange);font-size:1.22rem}
.eyebrow{color:#bc5700;font-size:.72rem;letter-spacing:.11em}
.hero{grid-template-columns:minmax(0,1fr) minmax(335px,1fr);gap:16px;align-items:stretch}
.hero-panel{min-height:0;border-radius:18px;padding:27px 29px;background-color:#171e23;background-image:linear-gradient(#ffffff0b 1px,transparent 1px),linear-gradient(90deg,#ffffff0b 1px,transparent 1px);background-size:29px 29px;display:flex;flex-direction:column}
.hero-panel:after{display:none}
.hero-panel .eyebrow{color:#ff9c43}
.hero-panel h2{font-size:clamp(2rem,3.15vw,3rem);margin:13px 0 10px}
.hero-panel p{margin:0;color:#c4ced0;line-height:1.7}
.hero-panel .hero-actions{margin-top:22px}
.hero-trace{display:flex;align-items:center;gap:9px;margin-top:auto;padding-top:21px;color:#aab6b6;font-size:.72rem;font-weight:700;letter-spacing:.12em}
.hero-trace i{width:24px;height:1px;background:#fa892d}
.btn{border-radius:9px;min-height:44px;padding:10px 16px;background:#ff8117;color:#172027;transition:background .16s,transform .16s}
.btn:hover{background:#ff9d4b;transform:translateY(-1px)}
.btn.secondary{background:#ecefeb;color:#263139}
.btn.secondary:hover{background:#dfe6df}
.btn.dark{background:#303a41}
.btn.dark:hover{background:#455159}
.btn.small-btn{min-height:38px;padding:8px 12px}
.explorer{padding:23px 25px;display:flex;flex-direction:column;justify-content:center}
.explorer .barline{align-items:start}
.explorer h2{font-size:1.34rem;line-height:1.3;margin:4px 0 13px}
.explorer-badge{font-size:.68rem;letter-spacing:.02em;background:#fdf1e4;color:#a45000;padding:5px 8px;border-radius:6px;white-space:nowrap;font-weight:800}
.explorer .field{margin:5px 0 11px}
.explorer .field .barline{align-items:center}
.explorer .field strong{color:#c65a00;font-size:1.05rem}
.explorer .field input[type=range]{margin-top:8px;width:100%;accent-color:#f47707}
.explorer-output{border-top:1px solid #e5e5de;display:flex;align-items:baseline;justify-content:space-between;gap:10px;padding-top:11px;color:#596870;font-size:.85rem;font-weight:700}
.explorer-output .metric{margin:0;color:#d96500;font-size:clamp(2.25rem,3.5vw,3.45rem)}
.explorer .formula{margin:8px 0 0}
.explorer p.small{margin:9px 0 12px}
.explorer .btn{align-self:flex-start}
.metric{color:#d96500}
.formula{background:#f0f2ee;border-left:3px solid #ff8a25;border-radius:0 8px 8px 0;font-variant-numeric:tabular-nums}
.progress-track{background:#e9e8e2}
.progress-track span{background:#f47707}
.segmented{padding:5px;background:#e9ebe7;border:1px solid #dce1dc;border-radius:12px;gap:4px;margin-bottom:16px}
.segmented button{flex:1;min-width:94px;background:transparent;border:0;border-radius:8px;color:#4d5960;padding:10px 12px}
.segmented button:hover{background:#f8f9f5}
.segmented button[aria-pressed=true]{background:#202a30;color:#fff}
.lab-grid{align-items:start;grid-template-columns:minmax(280px,.85fr) minmax(0,1.15fr)}
.lab-grid .card{min-height:0}
.lab-grid h2{font-size:1.38rem;margin:5px 0 14px}
.lab-input .field{margin-bottom:12px}
.lab-input .field input{background:#fbfcfa}
.lab-input .small{margin:0 0 15px}
.lab-input p:last-child{margin:12px 0 0}
.lab-output .result{margin:13px 0 11px;background:#fff7ef;border:1px solid #f4d9bf;padding:17px}
.lab-output .metric{margin:4px 0;font-size:clamp(2rem,3vw,3.1rem)}
.lab-output .formula{margin-bottom:9px}
.lab-output .btn{margin-top:1px}
.equation-flow{display:flex;align-items:center;gap:8px;flex-wrap:wrap;color:#4b5b62;font-size:.79rem;font-weight:700;margin:12px 0}
.equation-flow span,.equation-flow strong{padding:7px 9px;border:1px solid #e1e5df;border-radius:7px;background:#f7f8f5}
.equation-flow strong{background:#202a30;color:#fff;border-color:#202a30}
.equation-flow b{color:#e4750d}
.resource-filter{padding-bottom:15px}
.resource-filter .barline{border-top:1px solid #eceeea;padding-top:14px}
.resource-grid{margin-top:16px;align-items:start}
.resource-card{gap:10px}
.resource-card h3{font-size:1.08rem;line-height:1.45;margin:0}
.resource-variants{display:grid;gap:5px;margin-top:4px}
.resource-link{display:flex;align-items:center;justify-content:space-between;gap:12px;border:1px solid #e5e9e5;border-radius:8px;padding:8px 11px;color:#334149;font-size:.85rem;font-weight:700;background:#fbfcfa}
.resource-link:hover,.resource-link:focus-visible{border-color:#f78b2c;background:#fff7ef}
.resource-link span:last-child{color:#b45700;font-size:.73rem}
.footer-note{margin-top:35px;padding-top:17px;border-top:1px solid #e0e3df;color:#737d80;line-height:1.8}
@media(max-width:1120px){
 .shell{grid-template-columns:210px minmax(0,1fr)}
 main{padding:28px 24px 68px}
 .hero{grid-template-columns:minmax(0,.9fr) minmax(300px,1.1fr)}
 .hero-panel{padding:24px}
 .hero-panel h2{font-size:2.15rem}
}
@media(max-width:860px){
 .hero{grid-template-columns:1fr}
 .hero-panel{min-height:270px}
 .explorer{min-height:320px}
 .lab-grid{grid-template-columns:1fr}
 .grid.three{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:760px){
 .shell{display:block}
 .sidebar{height:auto;position:relative;padding:11px 16px}
 main{padding:23px 16px 98px}
 .hero-panel{min-height:0;padding:24px}
 .hero-panel h2{font-size:2.25rem}
 .explorer{min-height:0;padding:20px}
 .explorer .barline{flex-wrap:wrap}
 .grid.two,.grid.three{grid-template-columns:1fr}
 .segmented{overflow-x:auto;flex-wrap:nowrap}
 .segmented button{white-space:nowrap;flex:none}
 .mobile-nav .nav-link{font-size:.68rem;padding:5px 7px}
 .mobile-nav .ico{width:22px;height:22px}
 .mobile-nav svg{width:19px;height:19px}
 .resource-filter .barline{align-items:flex-start;flex-direction:column}
 .resource-filter .field{min-width:0;width:100%}
 .resource-tools{display:grid}
 .equation-flow{gap:5px;font-size:.72rem}
}
@media(max-width:390px){
 .explorer-output{align-items:start;flex-direction:column}
 .topline .date{display:none}
 .hero-actions .btn{width:100%}
}
@media(prefers-reduced-motion:reduce){.btn:hover{transform:none}}