@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;450;500;550;600;650;700&family=Space+Grotesk:wght@400;500;600;700&display=swap');
:root{color-scheme:light;--ink:#182a3b;--muted:#667686;--line:#dce3e8;--green:#087f69;--mint:#53dfbd;--navy:#102439}*{box-sizing:border-box}body{margin:0;background:#f3f6f8;color:var(--ink);font-family:'DM Sans',system-ui,sans-serif;font-size:16px}button,input,select{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #008eac;outline-offset:4px}header{height:86px;padding:0 4.5%;display:flex;justify-content:space-between;align-items:center;background:#fff;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:13px;font-family:'Space Grotesk',sans-serif;font-size:30px;font-weight:700;text-decoration:none;color:var(--ink)}.brand-icon{background:var(--navy);color:var(--mint);width:35px;height:39px;border-radius:9px;text-align:center;line-height:39px;font-size:28px}.brand-divider{height:25px;width:1px;background:var(--line);margin:0 7px}.brand-sub{font-family:'DM Sans',sans-serif;font-size:15px;font-weight:500}.course{font-size:12px;letter-spacing:1px;color:var(--muted)}.course b{margin-left:15px;border:1px solid var(--line);padding:8px 10px;border-radius:5px;font-size:12px}main{max-width:1480px;margin:auto;padding:34px 4.5% 0}.intro{display:flex;justify-content:space-between;align-items:center;margin-bottom:29px}.eyebrow{font-size:11px;letter-spacing:1.7px;font-weight:700;color:var(--green)}h1{font-family:'Space Grotesk',sans-serif;font-size:32px;letter-spacing:-1px;font-weight:600;margin:10px 0}p{color:var(--muted);line-height:1.55;margin:8px 0}.intro p{font-size:15px}.author{font-size:13px;color:var(--muted);line-height:1.8;text-align:right}.author strong{font-size:14px;color:var(--ink);font-weight:500}nav{display:grid;grid-template-columns:repeat(5,1fr);gap:5px;background:#e6ecef;padding:5px;border-radius:11px;margin-bottom:22px}nav button{border:0;background:none;color:#586878;border-radius:7px;padding:15px 10px;font-weight:600;font-size:15px}nav button span{font-size:12px;font-weight:400;margin-right:10px;opacity:.6}nav button.active{background:var(--navy);color:white;box-shadow:0 3px 7px #10243915}nav button:hover:not(.active){background:#ffffff80}.workspace{display:grid;grid-template-columns:300px minmax(0,1fr);gap:22px}.panel{background:white;border:1px solid var(--line);border-radius:12px;overflow:hidden}.panel-head{display:flex;justify-content:space-between;align-items:center;padding:20px 24px;gap:12px}h2{font-family:'Space Grotesk',sans-serif;font-size:18px;letter-spacing:-.4px;margin:0;font-weight:600}.parameters .panel-head{border-bottom:1px solid #e9edef;padding:18px 22px}.icon-button{background:none;border:1px solid var(--line);border-radius:6px;color:var(--muted);width:30px;height:30px;font-size:21px}#controls{padding:18px 22px 5px}.control{margin-bottom:20px}.control label{font-size:14px;display:block;font-weight:500;margin-bottom:8px}.input-wrap{display:flex;align-items:center;border:1px solid #dbe2e7;border-radius:6px;overflow:hidden;background:#fafcfd}.input-wrap input{width:100%;min-width:0;border:0;background:transparent;padding:7px 10px;color:var(--ink);font-family:'Space Grotesk',sans-serif;font-size:16px}.input-wrap span{font-size:12px;white-space:nowrap;color:var(--muted);padding:0 10px}.control input[type=range]{display:block;width:100%;height:4px;margin:13px 0 4px;accent-color:var(--green);cursor:pointer}.ends{display:flex;justify-content:space-between;font-size:11px;color:#8594a1;margin-top:6px}.control select{width:100%;padding:9px;border:1px solid var(--line);background:#fafcfd;border-radius:6px;color:var(--ink);font-size:14px}.tip{margin:4px 22px 20px;padding:12px;background:#f0f7f6;color:#51756c;font-size:12px;line-height:1.6;border-radius:6px}.experiment .panel-head{padding:22px 25px}.experiment h2{font-size:23px;margin-top:5px}.live{font-size:12px;color:var(--green);background:#eaf8f2;padding:6px 9px;border-radius:5px;white-space:nowrap}.live:before{content:'';display:inline-block;width:6px;height:6px;border-radius:50%;background:var(--green);margin-right:6px}.scene{background-color:var(--navy);background-image:radial-gradient(#66839833 1px,transparent 1px);background-size:20px 20px;margin:0 24px;border-radius:8px;min-height:290px;display:grid;place-items:center;overflow:hidden}.scene svg{width:100%;display:block;max-height:330px}.scene text{font-family:'DM Sans',sans-serif;font-size:13px}.scene-footer{display:flex;justify-content:space-between;align-items:center;padding:13px 24px;color:var(--muted);font-size:12px;gap:10px}.play{background:white;border:1px solid var(--line);padding:8px 12px;border-radius:6px;font-size:12px;color:var(--ink);white-space:nowrap}.metrics{display:grid;grid-template-columns:repeat(3,1fr);padding:14px 24px 24px;gap:14px}.metric{border-right:1px solid var(--line);padding-right:10px}.metric:last-child{border:0}.metric-label{font-size:12px;color:var(--muted);margin-bottom:8px}.metric-value{font-family:'Space Grotesk',sans-serif;font-size:28px;font-weight:500;letter-spacing:-1px}.metric-value small{font-family:'DM Sans',sans-serif;font-size:13px;color:var(--muted);margin-left:5px;letter-spacing:0}.metric:first-child .metric-value{color:var(--green)}.lower{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(0,1fr);gap:22px;margin-top:22px}.small{font-size:10px;color:var(--muted);letter-spacing:1px}.chart-panel svg{display:block;width:100%;height:215px}.chart-note{font-size:12px;margin:3px 24px 20px}.explanation .panel-head{padding-bottom:14px}.book-icon{color:var(--green);font-family:serif;font-size:24px}#explanation{padding:0 24px 23px;font-size:14px;line-height:1.6}.status{display:inline-block;padding:4px 9px;border-radius:4px;background:#e9f6f1;color:var(--green);font-size:12px;font-weight:600;margin-bottom:6px}.status.warn{background:#fff1d9;color:#8c5c0b}.formula{background:#f4f7f9;border-left:3px solid #60b5a2;border-radius:0 5px 5px 0;padding:11px 14px;font-family:'Space Grotesk',sans-serif;font-size:16px;margin:12px 0}.substitution{font-size:13px;color:var(--muted)}footer{display:flex;justify-content:space-between;gap:20px;padding:24px 0;font-size:11px;color:var(--muted)}footer strong{font-family:'Space Grotesk';font-size:16px;color:var(--ink);margin-right:5px}.invalid{border-color:#c66620!important}.error-box{padding:30px;color:#ffd699;text-align:center;line-height:1.6}.note{font-size:12px}.mobile-only{display:none}@media(min-width:1200px){.workspace{grid-template-columns:310px minmax(0,1fr)}.scene{min-height:310px}}@media(max-width:850px){header{height:70px}.course{display:none}.intro h1{font-size:27px}.author{display:none}.workspace{grid-template-columns:250px minmax(0,1fr)}.metrics{padding:12px 18px 20px;gap:8px}.metric-value{font-size:23px}.scene{margin:0 15px;min-height:280px}.experiment .panel-head{padding:18px}.live{display:none}.lower{grid-template-columns:1fr}.small{font-size:11px}}@media(max-width:620px){header{padding:0 20px}.brand{font-size:25px}.brand-sub{font-size:12px}.brand-divider{margin:0}.brand{gap:9px}main{padding:25px 16px 0}.intro{margin-bottom:20px}h1{font-size:25px!important}.intro p{font-size:14px}.eyebrow{font-size:10px}nav{gap:2px}nav button{font-size:12px;padding:13px 2px}nav button span{display:none}.workspace{display:flex;flex-direction:column;gap:16px}#controls{display:grid;grid-template-columns:1fr 1fr;gap:0 18px}.parameters .panel-head{padding:13px 20px}.control{margin-bottom:16px}.tip{margin-bottom:15px}.scene{min-height:240px}.scene svg{min-height:220px}.metrics{padding:12px 20px 22px}.metric-value{font-size:24px}.metric-value small{font-size:11px;display:block;margin:2px 0 0}.metric-label{font-size:11px}.scene-footer{padding:12px 18px}.lower{margin-top:16px;gap:16px}.panel-head{padding:18px 20px}.chart-panel h2{font-size:16px}footer{flex-direction:column;gap:10px}.chart-panel svg{height:auto}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}

.control{margin-bottom:14px}.control label{margin-bottom:6px}.control input[type=range]{margin-top:10px}.experiment{display:flex;flex-direction:column}.experiment .scene{flex:1}.experiment .metrics{margin-top:0}.error-box p{color:#ffd699}.play:disabled{opacity:.5;cursor:default}