:root{--ink:#193530;--muted:#60776d;--line:#d9e4de;--green:#11685e;--green-dark:#0b4d46;--soft:#eaf3ee;--gold:#b88432;--paper:#fff;--bg:#f4f6f2;--danger:#a54d3f;font-family:Inter,"PingFang TC","PingFang HK","Microsoft JhengHei",system-ui,sans-serif;color:var(--ink);font-size:15px}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);min-height:100vh}
button,input,select{font:inherit}
button,select{cursor:pointer}
button{border:1px solid var(--line);border-radius:9px;background:#fff;color:var(--ink);min-height:42px;padding:9px 13px;transition:background .12s,border-color .12s,transform .12s}
button:hover{background:var(--soft);border-color:#a9cabe}
button:active{transform:translateY(1px)}
button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #8ec4b4;outline-offset:2px}
button:disabled{opacity:.5;cursor:default;transform:none}
.primary{background:var(--green);border-color:var(--green);color:#fff;font-weight:700}
.primary:hover{background:var(--green-dark);border-color:var(--green-dark)}
.secondary{background:#fff;border-color:#a9cabe;color:var(--green);font-weight:650}
.large{padding:12px 22px;min-height:48px}
.text-button{background:transparent;border-color:transparent;color:var(--muted)}
.link-button{text-decoration:none;display:inline-flex;align-items:center;justify-content:center}
.game-header{height:76px;padding:0 clamp(14px,4vw,46px);display:flex;align-items:center;gap:16px;background:#fff;border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink)}
.brand img{flex:none}
.brand strong{display:block;font-size:19px;letter-spacing:.5px}
.brand small{display:block;margin-top:3px;color:var(--muted);font-size:10px;letter-spacing:1px}
.header-meta{margin-left:auto;display:flex;align-items:center;gap:13px}
.credit{font-size:11px;color:#587168;white-space:nowrap}
.language-label select{min-width:92px;border:1px solid var(--line);border-radius:8px;background:white;color:var(--ink);padding:8px 10px;min-height:40px}
.game-shell{max-width:1350px;margin:0 auto;padding:36px clamp(14px,4vw,46px) 80px}
.card{background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 5px 22px #2546380b}
.welcome-card,.complete-card{max-width:690px;margin:9vh auto 0;padding:48px clamp(25px,6vw,68px);text-align:center}
.eyebrow{color:var(--green);font-size:11px;letter-spacing:2px;font-weight:750;margin:0 0 11px}
.welcome-card h1,.complete-card h1,.game-topline h1{font-size:clamp(28px,4vw,44px);line-height:1.2;margin:0 0 15px;font-weight:750}
.lead{color:#51685f;line-height:1.85;font-size:16px;margin:0 auto;max-width:520px}
.welcome-actions{display:flex;justify-content:center;align-items:center;gap:10px;flex-wrap:wrap;margin:30px 0 20px}
.privacy-note{font-size:11px;color:var(--muted);line-height:1.7;margin:0}
.game-topline{display:flex;justify-content:space-between;align-items:end;gap:20px;margin-bottom:19px}
.game-topline .eyebrow{margin-bottom:7px}
.game-topline h1{font-size:32px;margin:0}
.progress-wrap{min-width:230px;color:var(--muted);font-size:12px;text-align:right}
.progress-track{height:8px;background:#e5ebe6;border-radius:10px;overflow:hidden;margin-top:8px}
.progress-track span{display:block;height:100%;width:12.5%;background:var(--green);border-radius:inherit;transition:width .25s}
.prompt-card{display:grid;grid-template-columns:58px 1fr;gap:18px;align-items:start;background:var(--soft);border:1px solid #cfe0d5;border-radius:13px;padding:18px 22px;margin-bottom:18px}
.question-number{width:43px;height:43px;display:grid;place-items:center;background:var(--green);border-radius:11px;color:#fff;font-weight:750;font-variant-numeric:tabular-nums}
.prompt-card h2{font-size:18px;margin:1px 0 8px}
.prompt-card p{margin:0;color:#3e5b50;line-height:1.75;font-size:15px}
.prompt-card .task-note{font-size:12px;color:#60776d;margin-top:8px}
.work-grid{display:grid;grid-template-columns:minmax(0,1fr) 318px;gap:18px;align-items:start}
.diagram-card{background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;min-width:0}
.diagram-toolbar{display:flex;align-items:center;justify-content:space-between;gap:9px;padding:11px 14px;border-bottom:1px solid var(--line);background:#fbfcfa}
.tool-group{display:flex;align-items:center;gap:6px;flex-wrap:wrap}
.tool-button{min-height:40px;font-size:12px;padding:8px 11px}
.tool-button.active{background:var(--soft);border-color:#8dbbab;color:var(--green);font-weight:700}
.secondary-tools{margin-left:auto}
.canvas-instruction{padding:10px 15px;margin:0;background:#fffdf5;border-bottom:1px solid #eee3bf;color:#725f35;font-size:12px;line-height:1.6}
.canvas-wrap{background:#e8eeea;padding:14px;overflow:auto}
.canvas-wrap svg{display:block;width:100%;height:auto;min-width:0;background:#fff;border:1px solid #d6e0d9;touch-action:none;user-select:none}
.canvas-footer{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:9px 15px;min-height:43px;color:var(--muted);font-size:11px}
.coordinate-note{white-space:nowrap}
.side-column{display:grid;gap:14px}
.inspector-card,.check-card,.checklist-card{padding:17px}
.card-heading{display:flex;align-items:baseline;justify-content:space-between;gap:8px;border-bottom:1px solid var(--line);padding-bottom:12px;margin-bottom:14px}
.card-heading h2,.checklist-card h2{font-size:15px;margin:0}
.card-heading span{font-size:11px;color:var(--green);font-weight:650}
.empty-inspector{color:var(--muted);font-size:12px;line-height:1.8;padding:5px 0 6px}
.field{display:block;color:#63786e;font-size:11px;margin:0 0 12px}
.field input{display:block;width:100%;margin-top:6px;min-height:42px;border:1px solid var(--line);border-radius:8px;padding:9px 10px;color:var(--ink);background:#fcfdfb}
.field input::placeholder{color:#b5c1ba}
.field-row{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.field-hint{color:var(--muted);font-size:11px;line-height:1.65;margin:0 0 13px}
.nudge-row{display:grid;grid-template-columns:repeat(4,1fr);gap:5px;margin:6px 0 13px}
.nudge-row button{font-size:19px;min-height:38px;padding:2px}
.check-grid{display:grid;gap:9px;margin:2px 0 14px;font-size:12px;color:#496158}
.check-grid input{accent-color:var(--green);width:16px;height:16px;vertical-align:-3px}
.danger-button{width:100%;color:var(--danger);background:#fff;border-color:#e5c2bc;font-size:11px}
.danger-button:hover{background:#fff4f1;border-color:#cf8c80}
.check-card{display:grid;gap:11px}
.check-button{width:100%;font-size:15px;min-height:50px}
.feedback{min-height:47px;background:#f6f8f5;border-radius:9px;padding:10px 12px;color:var(--muted);font-size:12px;line-height:1.65}
.feedback.success{background:#eaf6ed;color:#1a6844;border:1px solid #bdddc9}
.feedback.error{background:#fff5ef;color:#87513f;border:1px solid #eccbbc}
.next-button{width:100%;min-height:45px}
.checklist-card{color:#557066}
.checklist-card h2{color:var(--ink);margin-bottom:10px}
.checklist-card ul{padding-left:20px;margin:0}
.checklist-card li{font-size:12px;line-height:1.9}
.complete-card p:not(.eyebrow){color:#50685e;line-height:1.8}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
[hidden]{display:none!important}
.axis-line{stroke:#303d38;stroke-width:2.1}
.axis-arrow{fill:#303d38}
.axis-label{fill:#263e35;font-size:26px;font-weight:500}
.origin-label,.curve-label,.equilibrium-label,.guide-label{font-family:Georgia,"Times New Roman",serif;font-size:28px;font-weight:400;fill:#263e35}
.curve-line{fill:none;stroke-width:3.2;stroke-linecap:round}
.curve-line.demand{stroke:#2b776b}.curve-line.supply{stroke:#ad6e38}
.curve-label.demand{fill:#286b60}.curve-label.supply{fill:#995d2c}
.curve-label,.equilibrium-label{pointer-events:all;cursor:pointer}
.curve-hit{fill:none;stroke:transparent;pointer-events:stroke;cursor:grab}
.curve-hit:active,.point-hit:active{cursor:grabbing}
.curve-selection{stroke:#719e8e;stroke-width:12;opacity:.18;stroke-linecap:round}
.equilibrium-point{fill:#263e35;stroke:none;pointer-events:none}
.point-hit{fill:transparent;stroke:none;pointer-events:all;cursor:grab}
.point-selection{fill:#11685e18;stroke:#749e8e;stroke-width:1.5;pointer-events:none}
.guide-line{stroke:#6c7c74;stroke-width:1.6;stroke-dasharray:6 6;pointer-events:none}
.guide-label{fill:#354c41;pointer-events:none}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}
@media(max-width:980px){.work-grid{grid-template-columns:minmax(0,1fr) 276px}
.game-topline h1{font-size:28px}
.coordinate-note{white-space:normal;text-align:right}
}
@media(max-width:760px){.game-header{height:auto;min-height:72px;padding:9px 14px;flex-wrap:wrap;gap:7px}
.brand strong{font-size:17px}
.brand small{font-size:9px}
.header-meta{margin-left:auto;gap:6px}
.credit{order:3;width:100%;padding-left:46px;font-size:9px;margin-top:-5px}
.language-label select{min-width:80px;padding:7px 5px;font-size:12px}
.game-shell{padding:24px 12px 70px}
.welcome-card,.complete-card{margin-top:5vh;padding:34px 21px}
.welcome-card h1,.complete-card h1{font-size:30px}
.lead{font-size:14px}
.game-topline{align-items:start;flex-direction:column;gap:13px;margin-bottom:14px}
.game-topline h1{font-size:27px}
.progress-wrap{width:100%;min-width:0;text-align:left}
.prompt-card{grid-template-columns:46px 1fr;gap:11px;padding:14px}
.question-number{width:38px;height:38px;font-size:13px}
.prompt-card h2{font-size:16px}
.prompt-card p{font-size:14px}
.work-grid{display:flex;flex-direction:column}
.diagram-card{order:1;width:100%}
.side-column{order:2;width:100%}
.diagram-toolbar{align-items:stretch;flex-direction:column}
.secondary-tools{margin-left:0;display:grid;grid-template-columns:1fr 1fr}
.tool-group:first-child{display:grid;grid-template-columns:1fr 1fr}
.tool-button{min-height:46px}
.canvas-instruction{font-size:11px}
.canvas-wrap{padding:7px}
.canvas-wrap svg{min-width:0}
.canvas-footer{align-items:flex-start;flex-direction:column;gap:4px;padding:9px 12px}
.coordinate-note{text-align:left}
.inspector-card,.check-card,.checklist-card{padding:14px}
.check-button{min-height:54px}
.field input{font-size:16px}
.complete-card .welcome-actions{flex-direction:column}
.complete-card .large{width:100%}
}


.curve-label{pointer-events:all;cursor:pointer}
.equilibrium-label{pointer-events:all;cursor:pointer}
.compact-diagram .curve-label,.compact-diagram .equilibrium-label,.compact-diagram .guide-label,.compact-diagram .origin-label{font-size:40px}
.compact-diagram .axis-label{font-size:34px}

/* Familiar studio layout: tools / drawing / properties. */
.game-shell{max-width:1560px;padding-left:24px;padding-right:24px}
.work-grid{grid-template-columns:138px minmax(0,1fr) 286px;gap:14px}
.toolbox{padding:14px 10px;position:sticky;top:12px}
.toolbox h2{font-size:13px;margin:0 0 13px}
.studio-tools{display:grid;gap:7px;margin-bottom:12px}
.studio-tools button{display:flex;align-items:center;gap:9px;text-align:left;min-height:48px}
.studio-tools button>span:first-child{font-size:22px}
.toolbox #duplicateBtn{width:100%;margin-bottom:14px}
.studio-link{font-size:11px;color:var(--green);line-height:1.6;display:block;margin-top:15px}
.view-controls{display:flex;align-items:center;justify-content:flex-end;gap:8px;flex-wrap:wrap;padding:10px;border-top:1px solid var(--line);font-size:12px}
.view-controls label{display:flex;gap:4px;align-items:center}
.view-controls button{padding:5px 10px;min-height:34px}
.canvas-wrap{max-height:78vh;overflow:auto}
.canvas-wrap svg{max-width:none}
.object-section{border-top:1px solid var(--line);margin-top:18px;padding-top:10px}
.object-section h3{font-size:12px;margin:4px 0 10px}
.object-row{display:block;text-align:left;width:100%;min-height:34px;padding:6px 9px;margin-bottom:5px;font-size:12px}
.object-row.selected{background:var(--soft);border-color:#8dbbab}
#arrowInspector button{width:100%;margin:0 0 10px}
.movement-arrow{fill:none;stroke:#263e35;stroke-width:2.5;stroke-linecap:round}
.arrow-handle{fill:white;stroke:#11685e;stroke-width:2;cursor:crosshair}
.editor-grid{stroke:#e7eeea;stroke-width:1;pointer-events:none}
.feedback ul{margin:0;padding-left:17px}.feedback li+li{margin-top:8px}
.feedback.success{font-size:14px;font-weight:600}
.dialog-actions{display:flex;gap:10px;justify-content:center}
dialog{border:1px solid var(--line);border-radius:18px;max-width:min(620px,calc(100vw - 30px));padding:32px;color:var(--ink);text-align:center;box-shadow:0 24px 90px #19353030}
dialog::backdrop{background:#102e2966}dialog h2{margin:10px 0;font-size:28px}dialog p{line-height:1.8;color:var(--muted)}
.success-icon{margin:auto;width:64px;height:64px;border-radius:50%;background:#eaf6ed;color:#11685e;font-size:38px;display:grid;place-items:center}
#exportDialog{width:820px;max-width:calc(100vw - 30px);max-height:92vh;overflow:auto}#exportPreview{width:100%;max-height:62vh;object-fit:contain}
@media(max-width:1100px){.work-grid{grid-template-columns:110px minmax(0,1fr) 244px;gap:10px}.game-shell{padding-left:14px;padding-right:14px}.toolbox{padding:12px 8px}.tool-button{padding:7px;font-size:11px}.diagram-toolbar{flex-wrap:wrap}.diagram-toolbar button{font-size:12px}}
@media(max-width:900px){.work-grid{grid-template-columns:110px minmax(0,1fr)}.side-column{grid-column:2;grid-template-columns:1fr 1fr;align-items:start}.checklist-card{grid-column:1/-1}.toolbox{grid-row:1/3}.game-shell{padding-top:22px}}
@media(max-width:760px){.work-grid{display:flex;flex-direction:column}.toolbox{position:static;width:100%;order:0;display:flex;align-items:center;gap:8px;flex-wrap:wrap}.toolbox h2,.toolbox .field-hint,.studio-link{display:none}.studio-tools{display:flex;gap:6px;margin:0;flex:1}.studio-tools button{flex:1;padding:6px 9px;justify-content:center}.toolbox #duplicateBtn{width:auto;margin:0;min-height:46px}.side-column{display:grid;grid-template-columns:1fr}.diagram-toolbar{flex-direction:row;gap:4px;padding:8px}.diagram-toolbar .tool-group{display:flex}.diagram-toolbar button{padding:7px}.canvas-wrap{max-height:70vh}.game-shell{padding:20px 10px 60px}.view-controls{justify-content:center;gap:6px}.checklist-card{grid-column:auto}dialog{padding:25px 20px}}
@media(max-width:760px){.game-header{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:5px 8px}.header-meta{display:contents}.brand{min-width:0}.brand strong{font-size:15px}.brand small{font-size:8px;letter-spacing:.6px}.language-label{grid-column:2;grid-row:1}.credit{grid-column:1/-1;grid-row:2;padding:0;margin:0;width:auto;justify-self:end;font-size:10px}}