@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Space+Grotesk:wght@400;500;600;700&display=swap');
:root{font-family:'DM Sans',system-ui,sans-serif;color:#172b3d;background:#f3f5f7;font-synthesis:none;--ink:#172b3d;--muted:#637180;--mint:#9ce8d1;--line:#dce2e7;--blue:#285ad7}
*{box-sizing:border-box}body{margin:0}button,a{-webkit-tap-highlight-color:transparent}button{font:inherit;cursor:pointer}button:disabled{cursor:not-allowed}button:focus-visible,a:focus-visible,[tabindex]:focus-visible{outline:3px solid #448af5;outline-offset:5px}button{color:inherit}button[hidden],[hidden]{display:none!important}a{color:inherit;text-decoration:none}.skip{position:fixed;top:-80px;left:20px;z-index:20;background:white;padding:15px}.skip:focus{top:12px}
.topbar{height:86px;border-bottom:1px solid var(--line);display:flex;align-items:center;gap:34px;padding:0 5%;background:#fff}.brand{display:flex;align-items:center;font:700 22px 'Space Grotesk',sans-serif;letter-spacing:1.2px}.brand-light{font-weight:400}.brand-icon{width:36px;height:36px;border-radius:9px;display:grid;place-items:center;background:var(--ink);color:var(--mint);font-size:34px;margin-right:12px;line-height:1}.tagline{color:var(--muted);font-size:14px;border-left:1px solid var(--line);padding-left:30px}.topbar>.quiet{margin-left:auto}.quiet{background:none;border:0;font-size:14px;font-weight:600;padding:11px 4px;white-space:nowrap}.quiet:hover{color:var(--blue)}.quiet span{margin-left:14px}
main{max-width:1360px;margin:auto;padding:43px 5% 22px}.heading{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:31px}.eyebrow{font:600 11px 'Space Grotesk',sans-serif;letter-spacing:1.9px;color:var(--muted)}h1,h2{font-family:'Space Grotesk',sans-serif;font-weight:500;margin:0}h1{font-size:44px;letter-spacing:-2px;margin:8px 0 10px}.heading p{font-size:15px;color:var(--muted);margin:0;line-height:1.6}.progress-caption{text-align:right;font-size:14px;color:var(--muted)}.progress-caption>span:first-child{font:500 27px 'Space Grotesk',sans-serif;color:var(--ink);margin-right:4px}.small-note{display:block;font-size:12px;margin-top:4px}.level-nav{border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:16px 0;display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:25px}.level-nav>div{display:flex;gap:10px;align-items:center}.level{border:1px solid transparent;background:none;width:36px;height:36px;font-family:'Space Grotesk',sans-serif;border-radius:50%;font-size:13px;color:#566776;position:relative}.level:hover:enabled{background:#e3eaf0}.level.current{background:var(--ink);color:#fff}.level.completed:not(.current){background:#d6eee5;color:#256953}.level:disabled{color:#8c98a2;background:#e9edf0}.level:disabled:after{content:'';height:4px;width:4px;background:#8c98a2;position:absolute;bottom:4px;left:15px;border-radius:50%}#stage-label{font:500 11px 'Space Grotesk',sans-serif;letter-spacing:1.5px;color:var(--muted)}
.workspace{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:24px;margin-bottom:24px}.model-panel{background:#13283b;border-radius:15px;color:white;overflow:hidden;position:relative}.panel-top{display:flex;justify-content:space-between;align-items:center;padding:24px 28px;gap:12px}.panel-top h2{font-size:20px;letter-spacing:-.4px;margin-top:7px}.model-panel .eyebrow{color:#9eafbe}.model-badge{font-size:12px;color:#c9d8e3;border:1px solid #3b4f61;padding:7px 12px;border-radius:20px;white-space:nowrap}.graph-wrap{background-image:radial-gradient(#45617766 .9px,transparent .9px);background-size:22px 22px;margin:0 17px;height:310px}#graph{width:100%;height:100%;overflow:visible}.edge{fill:none;stroke:#70889c;stroke-width:1.7}.edge.highlight{stroke:#9ce8d1;stroke-width:2.2}.world{cursor:pointer;outline:none}.world .halo{fill:none;stroke:#88e4c6;stroke-width:1.5;stroke-dasharray:3 5;opacity:0}.world.inspected .halo,.world:hover .halo,.world:focus .halo{opacity:1}.world .disc{fill:#20394f;stroke:#7790a5;stroke-width:1.5}.world.actual .disc{fill:#9ce8d1;stroke:#9ce8d1}.world text{fill:#edf4fa;text-anchor:middle;pointer-events:none}.world.actual text{fill:#143e3a}.world .world-name{font:500 15px 'Space Grotesk',sans-serif;opacity:.75}.world .atom-label{font:500 25px 'DM Sans',sans-serif}.world .actual-label{font:600 10px 'Space Grotesk',sans-serif;letter-spacing:1.7px;fill:#9ce8d1}.truth-indicator{font:700 12px 'DM Sans',sans-serif;fill:#13283b}.graph-legend{display:flex;gap:19px;padding:15px 27px 20px;align-items:center;color:#bacbd8;font-size:12px;flex-wrap:wrap}.graph-legend>span{display:flex;align-items:center;gap:7px}.actual-key{width:8px;height:8px;background:var(--mint);border-radius:50%;display:inline-block}.arrow-key{font-size:21px;font-style:normal;line-height:10px}.world-detail{border-top:1px solid #344758;padding:16px 27px;color:#baccd9;font-size:13px;line-height:1.6;background:#102333;min-height:54px}.world-detail strong{color:#e6f2f8;font-weight:500}
.mission-panel{border:1px solid var(--line);border-radius:15px;padding:27px 25px;background:#fff}.mission-panel h2{font-size:28px;line-height:1.2;letter-spacing:-1px;margin:18px 0}.mission-panel>p{font-size:14px;line-height:1.7;color:var(--muted);margin:0 0 25px}.mission-panel strong{color:var(--ink)}.rule{display:flex;align-items:flex-start;gap:12px;margin:21px 0}.rule-symbol{width:40px;height:42px;flex-shrink:0;display:grid;place-items:center;border-radius:8px;line-height:1}.diamond,.box{background:#e8f1fe;color:#285ad7}.rule strong{font-size:13px;font-weight:600}.rule p{font-size:13px;line-height:1.6;color:var(--muted);margin:5px 0}.rule em{font-style:normal;color:var(--ink)}.mission-note{border-top:1px solid var(--line);padding-top:18px;margin-top:24px;font-size:12px;line-height:1.7;color:var(--muted);display:flex;gap:10px}.mission-note>span{font-size:22px}
.formula-panel{background:white;border:1px solid var(--line);border-radius:15px;overflow:hidden}.formula-panel .panel-top{padding-bottom:18px}.builder{display:flex;padding:0 28px 24px;min-height:135px;align-items:stretch;gap:25px}.operator-bank{min-width:210px;max-width:250px;padding-right:24px;border-right:1px solid var(--line)}.bank-title{font:500 10px 'Space Grotesk',sans-serif;letter-spacing:1px;color:var(--muted);display:block}.bank-title #remaining{letter-spacing:0;margin-left:8px;color:#8a959f}#tokens{display:flex;gap:8px;flex-wrap:wrap;min-height:56px;padding-top:13px}.token{font:inherit;line-height:1;width:46px;height:48px;padding:0;border:1px solid #d0dcf1;border-radius:9px;box-shadow:0 3px 0 #d9e2ef;touch-action:none;user-select:none;cursor:grab;display:inline-grid;place-items:center}.token.selected{outline:3px solid #285ad7;outline-offset:3px}.token:active{cursor:grabbing}.token:hover{filter:brightness(.97)}.bank-note{font-size:11px;color:var(--muted);display:block;margin-top:12px}.empty-bank{font-size:13px;color:var(--muted);align-self:center}.formula-area{flex:1;min-width:0;display:flex;flex-direction:column;justify-content:center;align-items:center;padding-top:6px}.formula-scroll{max-width:100%;overflow-x:auto;padding:10px 8px 12px;width:100%;text-align:center}.formula{display:inline-flex;align-items:center;white-space:nowrap;font:32px Georgia,'Times New Roman',serif;min-height:57px;gap:4px}.formula .atom{font-style:italic;padding:0 4px}.formula .connective{padding:0 7px}.slot-wrap{display:inline-flex;align-items:center;gap:2px}.slot{position:relative;display:inline-flex;align-items:center;justify-content:center;min-width:24px;height:43px;border:0;border-radius:4px;background:transparent;color:inherit;font:inherit;padding:0;flex-shrink:0;isolation:isolate}.slot::before{content:'';position:absolute;inset:-2px -2px -18px -8px;border-radius:5px;z-index:-1}.slot-caret{position:absolute;bottom:-10px;left:-2px;width:6px;height:6px;border-left:1.5px solid #99a7b3;border-top:1.5px solid #99a7b3;transform:translateX(-50%) rotate(45deg);pointer-events:none}.slot:hover .slot-caret,.slot:focus-visible .slot-caret,.slot.drop-target .slot-caret,.slot.hint-target .slot-caret{border-color:var(--blue);border-width:2px}.slot.drop-target::before,.slot.hint-target::before{background:#e8f1fe}.slot:hover .formula-symbol,.slot.drop-target .formula-symbol{color:var(--blue)}.formula-scroll{padding-bottom:27px}.formula .token{width:34px;height:44px;border-radius:6px;box-shadow:none}.formula-area>p{font-size:12px;color:var(--muted);text-align:center;margin:8px 0 0;line-height:1.5}.action-row{border-top:1px solid var(--line);padding:18px 28px;display:flex;justify-content:space-between;align-items:center;gap:20px;background:#fafbfc}.feedback{font-size:13px;color:var(--muted);line-height:1.6;max-width:620px}.feedback.good{color:#216b52}.feedback.bad{color:#b14c36}.actions{display:flex;align-items:center;gap:22px;flex-shrink:0}.primary{background:var(--blue);color:white;border:1px solid var(--blue);padding:13px 20px;border-radius:8px;font-size:14px;font-weight:500;white-space:nowrap;box-shadow:0 2px 3px #183d8720}.primary:hover{background:#1949bd}.primary>span{margin-left:20px}.primary.success{background:#17674e;border-color:#17674e}.primary:disabled{opacity:.55}.evaluation{padding:14px 28px;font-size:13px;color:#566777;line-height:1.7;border-top:1px solid var(--line);overflow-wrap:anywhere}.evaluation strong{color:var(--ink)}footer{display:flex;justify-content:space-between;font-size:11px;color:#7b8793;margin-top:23px;gap:20px;line-height:1.7}.drag-ghost{position:fixed;z-index:100;pointer-events:none;opacity:.95;transform:translate(-50%,-50%) rotate(-6deg);box-shadow:0 8px 20px #172b3d30}.dragging{opacity:.3}.drop-bank{background:#e4f7ef}dialog{border:1px solid var(--line);border-radius:18px;max-width:580px;width:calc(100% - 32px);padding:28px 32px;color:var(--ink);max-height:90vh;overflow:auto;box-shadow:0 25px 100px #071e4850}dialog::backdrop{background:#0b203aba;backdrop-filter:blur(4px)}.dialog-top{display:flex;justify-content:space-between;align-items:center}dialog h2{font-size:29px;letter-spacing:-.8px;margin:13px 0 20px}dialog p{font-size:15px;line-height:1.7;color:#526170}dialog .primary{margin-top:8px}kbd{font:12px monospace;border:1px solid #bcc8d1;padding:2px 5px;border-radius:4px;background:#f6f8fa}
.world.actual .actual-label{fill:#9ce8d1}
@media(max-width:380px){.topbar{gap:10px}.brand{font-size:20px}.topbar>.quiet{font-size:12px}.topbar .quiet span{margin-left:6px}}
@media(min-width:761px){.topbar{height:72px}main{padding-top:28px}.heading{margin-bottom:23px}h1{font-size:38px;margin:6px 0 8px}.mission-panel h2{font-size:25px;margin:13px 0}.mission-panel>p{margin-bottom:18px}.rule{margin:15px 0}.mission-note{margin-top:17px;padding-top:14px}.graph-wrap{height:270px}.panel-top{padding-top:21px;padding-bottom:20px}.builder{min-height:117px}}
@media(min-width:1500px){main{padding-left:20px;padding-right:20px}.graph-wrap{height:300px}.mission-panel{padding:30px}.workspace{grid-template-columns:minmax(0,1fr) 320px}.heading{margin-bottom:28px}}
@media(max-width:1000px){.workspace{grid-template-columns:minmax(0,1fr) 260px;gap:18px}.mission-panel{padding:24px 20px}.mission-panel h2{font-size:25px}.graph-legend{gap:12px;padding-left:20px}.panel-top{padding:21px}.builder{padding:0 21px 22px;gap:18px}.operator-bank{min-width:170px;max-width:190px;padding-right:17px}.action-row{padding:18px 21px}.actions{gap:15px}.tagline{font-size:13px}.graph-wrap{height:300px}.formula{font-size:27px}}
@media(max-width:760px){.topbar{height:70px;padding:0 5%}.tagline{display:none}main{padding-top:26px}.heading{align-items:flex-end;margin-bottom:24px}h1{font-size:36px}.heading p{font-size:14px;max-width:260px}.heading .eyebrow{font-size:10px}.progress-caption{font-size:12px}.small-note{max-width:110px;font-size:10px}.workspace{grid-template-columns:1fr}.mission-panel{display:none}.level-nav{gap:8px}.level-nav>div{gap:5px}.level{width:32px;height:32px}.level:disabled:after{left:13px}#stage-label{font-size:9px;letter-spacing:.5px}.graph-wrap{height:290px}.builder{flex-direction:column;gap:16px}.operator-bank{border-right:0;border-bottom:1px solid var(--line);padding:0 0 17px;max-width:none;display:grid;grid-template-columns:1fr auto;align-items:center}.bank-title{grid-column:1}.bank-note{grid-column:1;grid-row:2;margin:7px 0 0}.operator-bank #tokens{grid-column:2;grid-row:1/3;padding-top:0;min-height:48px}.action-row{align-items:flex-start;flex-direction:column;gap:14px}.actions{width:100%;justify-content:space-between}.feedback{font-size:13px}.formula-panel .panel-top{padding:21px}.panel-top h2{font-size:18px}.formula-panel .quiet{font-size:12px}.graph-legend{justify-content:center}.world-detail{padding:14px 20px}footer{flex-direction:column;gap:3px;font-size:10px}.formula-area>p{font-size:11px}.evaluation{padding:14px 21px}}
@media(max-width:760px){.world .atom-label{font-size:25px}.world .world-name{font-size:15px}.world .actual-label{font-size:11px;letter-spacing:.7px}.graph-wrap{margin:0 9px}.model-panel .panel-top{padding-left:18px;padding-right:18px}.model-badge{font-size:11px;padding:7px 9px}.graph-legend{padding-top:10px;padding-bottom:15px}.operator-bank #tokens{max-width:108px}}
@media(prefers-reduced-motion:no-preference){.token,.slot,.primary{transition:background .15s,box-shadow .15s}.world .halo{transition:opacity .2s}.feedback.good{animation:appear .3s ease-out}@keyframes appear{from{opacity:.3;transform:translateY(3px)}to{opacity:1;transform:translateY(0)}}}

/* Shared 2px outlines; the diamond side is 93% of the 16px box side.
   Even tile dimensions avoid half-pixel offsets within the tiles. */
.operator-icon{display:block;width:16px;height:16px;border:2px solid currentColor;flex-shrink:0;pointer-events:none}
.operator-icon--diamond{width:14.88px;height:14.88px;transform:rotate(45deg)}