*{box-sizing:border-box}:root{--ink:#202942;--muted:#727c92;--line:#e2e6ef;--panel:#fff;--indigo:#5c61df;--indigo-dark:#4449bd;--coral:#ff705e;--gold:#f5ad3f;--teal:#1db79b;--navy:#34426d;--shadow:0 18px 52px rgba(39,49,81,.13)}html,body{width:100%;height:100%;margin:0;overflow:hidden}body{font-family:"DM Sans",system-ui,sans-serif;color:var(--ink);background:#eef1f8}button,input{font:inherit;color:inherit}.app-shell{width:100vw;height:100vh;display:grid;grid-template-rows:66px minmax(0,1fr);background:linear-gradient(135deg,#fafbfe,#edf0f7)}.topbar{display:flex;align-items:center;justify-content:space-between;padding:0 24px;background:rgba(255,255,255,.92);border-bottom:1px solid rgba(69,82,117,.12);backdrop-filter:blur(14px);z-index:5}.brand{display:flex;align-items:center;gap:11px}.brand-mark{width:39px;height:39px;border-radius:13px;display:grid;place-items:center;background:linear-gradient(145deg,var(--indigo),#989af6);color:#fff;font:800 22px/1 Manrope,sans-serif;box-shadow:0 8px 20px rgba(89,98,230,.28);transform:rotate(-4deg)}.brand p,.kicker,.section-heading p{margin:0;text-transform:uppercase;letter-spacing:.13em;font-size:9px;font-weight:800;color:var(--indigo)}h1,h2,h3,p{margin-top:0}h1{font:800 20px/1.05 Manrope,sans-serif;margin:3px 0 0}.top-actions{display:flex;gap:8px}.button{border:0;border-radius:10px;padding:10px 14px;font-weight:700;cursor:pointer;transition:.2s transform,.2s box-shadow,.2s background}.button:hover{transform:translateY(-1px)}.button:focus-visible,.preset-row button:focus-visible,.text-button:focus-visible,input:focus-visible{outline:3px solid rgba(89,98,230,.32);outline-offset:2px}.ghost{background:#eeeefe;color:var(--indigo-dark)}.ghost[aria-pressed=true]{background:var(--indigo);color:#fff}.quiet{background:#f0f2f6;color:#5e687d}.primary{background:var(--indigo);color:#fff;box-shadow:0 8px 18px rgba(89,98,230,.25)}.workspace{min-height:0;display:grid;grid-template-columns:minmax(0,1fr) 370px;gap:14px;padding:14px}.stage,.controls{min-height:0;border-radius:22px;background:var(--panel);border:1px solid rgba(92,104,137,.12);box-shadow:var(--shadow)}.stage{position:relative;overflow:hidden;display:grid;grid-template-rows:auto minmax(0,1fr);background:linear-gradient(145deg,#fff,#fafaff)}.stage-heading{display:flex;justify-content:space-between;align-items:flex-start;gap:18px;padding:20px 24px 8px}.stage-heading h2{font:800 clamp(18px,2vw,27px)/1.2 Manrope,sans-serif;margin:4px 0 0}.key{display:flex;gap:13px;color:var(--muted);font-size:11px;white-space:nowrap}.key span{display:flex;align-items:center;gap:6px}.key i{width:13px;height:13px;border-radius:4px}.key-a{background:var(--coral)}.key-b{background:var(--gold)}.key-c{background:var(--indigo)}.visual-wrap{position:relative;min-height:0;margin:0 18px 18px;border:1px solid #e8eaf2;border-radius:20px;overflow:hidden;background:radial-gradient(circle at 72% 22%,rgba(92,97,223,.1),transparent 34%),linear-gradient(180deg,#fbfbff,#f3f5fa)}#triangleScene{width:100%;height:100%;display:block}.square{stroke-width:2.5;stroke-linejoin:round}.square-a{fill:var(--coral);stroke:#e85b49}.square-b{fill:var(--gold);stroke:#db9226}.square-c{fill:var(--indigo);stroke:#454abc}.triangle{fill:#fff;stroke:var(--navy);stroke-width:4;stroke-linejoin:round}.right-angle{fill:none;stroke:var(--navy);stroke-width:3}.area-label{font:800 16px Manrope,sans-serif;text-anchor:middle;dominant-baseline:middle;pointer-events:none}.area-label-light{fill:#fff}.side-label{fill:#283454;font:800 13px Manrope,sans-serif;text-anchor:middle;paint-order:stroke;stroke:#fff;stroke-width:5px;stroke-linejoin:round}.proof-badge{position:absolute;right:15px;bottom:15px;min-width:205px;padding:11px 13px;border:1px solid rgba(89,98,230,.14);border-radius:13px;background:rgba(255,255,255,.95);box-shadow:0 10px 30px rgba(48,58,91,.1)}.proof-badge small{display:block;color:var(--muted);font-size:9px;text-transform:uppercase;letter-spacing:.08em;font-weight:800}.proof-badge strong{display:block;margin-top:3px;color:var(--indigo-dark);font:800 18px Manrope,sans-serif}.proof-badge p{margin:2px 0 0;color:var(--muted);font-size:9px}.challenge-card{position:absolute;inset:82px 34px 34px;z-index:4;display:grid;align-content:center;justify-items:center;text-align:center;padding:28px;border:1px solid rgba(89,98,230,.16);border-radius:20px;background:rgba(255,255,255,.97);box-shadow:0 20px 70px rgba(37,48,82,.2);backdrop-filter:blur(16px)}.challenge-copy h3{font:800 clamp(23px,2.5vw,34px)/1.2 Manrope,sans-serif;margin:7px 0}.challenge-copy>p:last-child{color:var(--muted);font-size:14px}.challenge-card form{width:min(430px,100%)}.challenge-card label{display:block;text-align:left;font-size:10px;text-transform:uppercase;letter-spacing:.1em;color:var(--muted);font-weight:800}.answer-row{display:grid;grid-template-columns:1fr auto auto;align-items:center;gap:8px;margin-top:7px}.answer-row input{width:100%;min-width:0;border:2px solid #dfe2ec;border-radius:12px;padding:11px 12px;font-weight:800}.answer-row>span{font-weight:700;color:var(--muted)}.feedback{min-height:22px;margin:9px 0 0;font-size:12px;font-weight:700}.feedback.correct{color:#128461}.feedback.try{color:#c05245}.text-button{border:0;background:transparent;padding:0;color:var(--indigo);font-size:10px;font-weight:800;cursor:pointer}.controls{display:flex;flex-direction:column;overflow:hidden}.control-section{padding:16px 18px;border-bottom:1px solid #eceef4}.section-heading{display:flex;align-items:center;gap:9px;margin-bottom:12px}.section-heading>span{width:23px;height:23px;border-radius:7px;display:grid;place-items:center;background:#eef0ff;color:var(--indigo);font-size:10px;font-weight:800}.section-heading h2{font:800 13px Manrope,sans-serif;margin:2px 0 0}.slider-label{display:flex;justify-content:space-between;font-size:11px;font-weight:700}.slider-label output{color:var(--indigo)}.slider-label.second{margin-top:6px}input[type=range]{width:100%;accent-color:var(--indigo);margin:9px 0 7px;cursor:pointer}.preset-row{display:grid;grid-template-columns:repeat(3,1fr);gap:7px}.preset-row button{border:1px solid #e1e4ec;border-radius:9px;padding:7px 3px;background:#f7f8fb;color:var(--muted);font-size:10px;font-weight:800;cursor:pointer}.preset-row button.active{border-color:var(--indigo);background:#eff0ff;color:var(--indigo-dark)}.measure-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:7px}.measure-grid article{padding:11px 8px;border:1px solid #e7e9f0;border-radius:13px;text-align:center}.measure-a{background:#fff2ef}.measure-b{background:#fff8e9}.measure-c{background:#f0f1ff}.measure-grid small{display:block;color:var(--muted);font-size:9px;text-transform:uppercase;letter-spacing:.08em;font-weight:800}.measure-grid strong{font:800 22px Manrope,sans-serif}.measure-a strong{color:#d95746}.measure-b strong{color:#bd7916}.measure-c strong{color:var(--indigo-dark)}.measure-grid span{display:block;font-size:8px;color:var(--muted)}.equation{display:flex;align-items:center;justify-content:center;gap:11px;padding:9px;border-radius:12px;background:linear-gradient(135deg,#eef0ff,#f8f8ff);color:var(--indigo-dark);font:800 22px Manrope,sans-serif}.equation b{font-size:14px;color:#8c94aa}.equation-section>p{margin:7px 0;text-align:center;color:var(--muted);font-size:10px;font-weight:700}.area-bar{display:flex;height:10px;overflow:hidden;border-radius:99px;background:#e7e9f4;margin:9px 0}.area-bar span{display:block;transition:width .3s ease}.bar-a{background:var(--coral)}.bar-b{background:var(--gold)}.constant-note{display:flex;gap:7px;padding:9px 10px;border-radius:11px;background:#f5f6fa;color:#687187}.constant-note>span{color:var(--indigo)}.constant-note p{margin:0;font-size:9px;line-height:1.4}.prompt-card{margin:12px 18px 16px;padding:13px;border-radius:14px;background:linear-gradient(135deg,#293152,#454d7c);color:#fff}.prompt-card>span{font-size:8px;text-transform:uppercase;letter-spacing:.1em;color:#c3c8ef;font-weight:800}.prompt-card p{font-size:11px;line-height:1.4;margin:5px 0 8px}.prompt-card .text-button{color:#c4c8ff}.prompt-card #revealText{color:#d7daef;font-size:9px}
@media(max-width:850px){.workspace{grid-template-columns:minmax(0,1fr) 330px}.control-section{padding-left:13px;padding-right:13px}.prompt-card{margin-left:13px;margin-right:13px}}
@media(max-width:700px){.app-shell{grid-template-rows:56px minmax(0,1fr)}.topbar{padding:0 11px}.brand-mark{width:32px;height:32px;font-size:18px}.brand p{display:none}h1{font-size:16px}.button{padding:8px 10px;font-size:10px}.workspace{grid-template-columns:1fr;grid-template-rows:minmax(0,56%) minmax(0,44%);padding:7px;gap:7px}.stage,.controls{border-radius:16px}.stage-heading{padding:9px 12px 3px}.stage-heading h2{font-size:13px}.kicker{font-size:7px}.key{display:none}.visual-wrap{margin:0 8px 8px;border-radius:13px}.proof-badge{right:7px;bottom:7px;min-width:146px;padding:7px 8px}.proof-badge small{font-size:7px}.proof-badge strong{font-size:12px}.proof-badge p{font-size:7px}.controls{display:grid;grid-template-columns:1fr 1fr;grid-template-rows:auto auto;align-content:start}.control-section{padding:8px 10px}.control-section:nth-child(3){grid-column:1/-1;padding-top:6px}.prompt-card{display:none}.section-heading{margin-bottom:5px}.section-heading h2{font-size:9px}.section-heading p{font-size:6px}.section-heading>span{width:18px;height:18px;font-size:8px}.slider-label{font-size:7px}.slider-label.second{margin-top:1px}input[type=range]{margin:4px 0 3px}.preset-row{gap:3px}.preset-row button{padding:4px 2px;font-size:7px}.measure-grid{gap:3px}.measure-grid article{padding:6px 3px}.measure-grid strong{font-size:14px}.measure-grid small{font-size:6px}.equation{padding:4px;font-size:15px}.equation-section>p{margin:3px 0;font-size:7px}.area-bar{height:6px;margin:4px 0}.constant-note{padding:5px 6px}.constant-note p{font-size:7px}.challenge-card{inset:56px 16px 16px;padding:14px}.challenge-copy h3{font-size:19px}.challenge-copy>p:last-child{font-size:10px}.answer-row input{padding:8px}.feedback{font-size:9px}}
@media(max-width:420px){.top-actions .ghost span{display:none}.workspace{grid-template-rows:minmax(0,55%) minmax(0,45%)}.stage-heading h2{font-size:12px}.control-section{padding:6px 8px}.constant-note p{font-size:6.5px}.challenge-card{inset:46px 10px 10px}.answer-row{grid-template-columns:1fr auto}.answer-row .button{grid-column:1/-1}.challenge-card form{max-width:270px}}
@media(min-width:701px) and (max-height:700px){.workspace{padding:9px;gap:9px}.stage-heading{padding:12px 18px 5px}.visual-wrap{margin:0 12px 12px}.control-section{padding-top:10px;padding-bottom:10px}.section-heading{margin-bottom:7px}.prompt-card{margin-top:8px;margin-bottom:8px;padding:9px}.challenge-card{inset:60px 28px 25px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}}