:root{--ink:#17342b;--forest:#124c38;--green:#24865f;--lime:#c9df70;--paper:#edf1ef;--white:#fbfdfc;--accent:#24865f;--muted:#61736d;--line:#cfd9d5;--alert:#61736d;--secondary:#74857f}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--paper);color:var(--ink);font-family:Arial,Helvetica,sans-serif;font-size:16px}a{color:inherit}.topbar{min-height:72px;padding:12px clamp(18px,5vw,72px);display:flex;align-items:center;justify-content:space-between;gap:20px;border-bottom:1px solid var(--line);background:#edf1eff5;position:sticky;top:0;z-index:10}.brand{display:flex;align-items:center;gap:11px;font-weight:850;text-decoration:none}.mark{width:38px;height:38px;border-radius:50%;display:grid;place-items:center;background:var(--forest);color:#fff;font:800 12px Georgia,serif}.back{font-weight:800;color:var(--forest);text-decoration:none}.lab{padding:clamp(28px,5vw,64px) clamp(18px,6vw,88px) 72px}.intro{max-width:980px;margin:0 auto 28px}.eyebrow{text-transform:uppercase;letter-spacing:.14em;color:var(--green);font-size:.78rem;font-weight:850}.intro h1{font:500 clamp(2.3rem,5vw,4.6rem)/1 Georgia,serif;letter-spacing:-.04em;margin:12px 0}.intro p{max-width:760px;color:var(--muted);font-size:1.08rem;line-height:1.6}.workspace{max-width:1180px;margin:auto;display:grid;grid-template-columns:minmax(250px,340px) 1fr;gap:24px}.panel,.stage,.challenge{background:var(--white);border:1px solid var(--line);box-shadow:0 12px 30px #17342b10}.panel{padding:24px}.stage{padding:24px;min-height:440px}.panel h2,.stage h2,.challenge h2{font:500 1.55rem Georgia,serif;margin:0 0 18px}.control{margin:0 0 22px}.control label{display:flex;justify-content:space-between;gap:12px;font-weight:750;margin-bottom:8px}.value{color:var(--accent);font-weight:850}.control input[type=range]{width:100%;accent-color:var(--green)}button,.button{border:0;background:var(--green);color:#fff;min-height:46px;padding:0 18px;font:800 1rem Arial;border-radius:4px;cursor:pointer}button:hover,.button:hover{background:var(--forest)}button.secondary{background:transparent;color:var(--forest);border:1px solid var(--forest)}.button-row{display:flex;flex-wrap:wrap;gap:10px}.formula{padding:16px;background:#e5f2ec;border-left:4px solid var(--accent);font:500 1.25rem Georgia,serif;line-height:1.5;margin:14px 0}.note{color:var(--muted);line-height:1.55}.challenge{max-width:1180px;margin:24px auto 0;padding:24px}.feedback{min-height:46px;margin-top:14px;padding:12px 14px;border-left:4px solid var(--lime);background:#f4f7e7;line-height:1.45}.feedback.ok{border-color:var(--green);background:#e7f5ee}.feedback.no{border-color:var(--alert);background:#edf1ef}.graph-wrap{width:100%;overflow:hidden}.graph-wrap canvas{display:block;width:100%;height:360px;background:#fff;border:1px solid var(--line)}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:16px 0}.stat{padding:14px;background:var(--paper);text-align:center}.stat strong{display:block;font-size:1.25rem;color:var(--accent)}.fraction-bar{display:grid;height:86px;border:2px solid var(--forest);margin:24px 0}.fraction-piece{border-right:1px solid #fff;background:#dde6e2}.fraction-piece.on{background:var(--accent)}.balance{position:relative;min-height:260px;padding-top:70px}.beam{height:10px;background:var(--forest);transform-origin:center;transition:transform .35s}.pivot{width:0;height:0;border-left:45px solid transparent;border-right:45px solid transparent;border-bottom:100px solid var(--green);margin:0 auto}.pans{display:flex;justify-content:space-between;margin-top:-122px;padding:0 5%}.pan{width:38%;min-height:105px;border:3px solid var(--accent);border-top:0;display:grid;place-items:center;padding:12px;font-weight:850;background:#edf4f1}.sign-line{display:grid;grid-template-columns:repeat(3,1fr);height:70px;border:2px solid var(--forest);margin-top:24px}.sign-line div{display:grid;place-items:center;font-weight:850}.positive{background:#dcebe5;color:#124c38}.negative{background:#e5e9e7;color:#46544f}.zero{background:var(--lime)}.triangle-svg{width:100%;height:330px;border:1px solid var(--line);background:linear-gradient(#ffffff 95%,#edf1ef 95%);background-size:100% 28px}.dice-chart{height:300px;display:flex;align-items:flex-end;gap:6px;border-left:2px solid var(--forest);border-bottom:2px solid var(--forest);padding:14px 8px 0}.bar{flex:1;min-width:12px;background:var(--accent);position:relative;transition:height .25s}.bar span{position:absolute;bottom:100%;left:50%;transform:translateX(-50%);font-size:.75rem}.bar b{position:absolute;top:100%;left:50%;transform:translate(-50%,6px);font-size:.75rem}.nav-labs{max-width:1180px;margin:28px auto 0;display:flex;justify-content:space-between;gap:12px}.nav-labs a{font-weight:800;color:var(--green)}footer{padding:28px;text-align:center;background:#0c2a20;color:#c7d3cf;font-size:.86rem}@media(max-width:780px){.workspace{grid-template-columns:1fr}.stage{min-height:360px}.graph-wrap canvas{height:300px}.stats{grid-template-columns:1fr}.back{font-size:.86rem}.topbar{align-items:flex-start}.pans{padding:0}.pan{width:43%}.dice-chart{height:250px}.nav-labs{flex-direction:column}}