*{box-sizing:border-box}body{margin:0;background:#f4f6f1;color:#263f36;font:14px/1.6 "Segoe UI","Microsoft YaHei",sans-serif}button,select,input{font:inherit}button,a,select{touch-action:manipulation}button{cursor:pointer;border:1px solid #cfdbd1;background:#fff;color:#2b5743;border-radius:7px;padding:8px 11px}button:hover{background:#eaf2e9}button:disabled{opacity:.4;cursor:default}button:focus-visible,a:focus-visible,select:focus-visible,input:focus-visible{outline:3px solid #e4a446;outline-offset:2px}header{height:68px;display:flex;align-items:center;gap:30px;padding:0 28px;background:#fcfdf9;border-bottom:1px solid #d9e2d8}header strong{font-size:17px}.brand{color:#396a51;text-decoration:none}.badge{margin-left:auto;font-size:12px;background:#f9efd9;color:#8d6226;padding:5px 12px;border-radius:20px}main{height:calc(100vh - 68px);display:grid;grid-template-columns:minmax(0,1fr) 385px}#stage{position:relative;overflow:hidden;min-width:0;background:radial-gradient(ellipse at center,#fff,#edf1e9)}#canvas{display:block;width:100%;height:100%;touch-action:none}.intro{position:absolute;top:24px;left:28px;pointer-events:none}.intro span{font-size:10px;letter-spacing:1.7px;color:#76927a}.intro h1{font-size:29px;margin:5px 0}.intro p{margin:0;font-size:12px;color:#7b8d7c}#loading{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);padding:14px 20px;background:#fff;border:1px solid #d0ded0;border-radius:9px;max-width:80%;text-align:center}.views{display:flex;gap:4px;position:absolute;bottom:24px;left:50%;transform:translateX(-50%);padding:6px;background:#fffffff0;border:1px solid #d3dfd1;border-radius:10px;white-space:nowrap}.views button{border:0;padding:8px 11px;font-size:12px}.stage-note{position:absolute;bottom:84px;left:28px;font-size:11px;color:#6e826d;pointer-events:none}.endpoint{position:absolute;pointer-events:none;max-width:260px;padding:6px 10px;border-radius:6px;background:#285642f5;color:#fff;font-size:12px;box-shadow:0 2px 8px #19332425;transform:translate(-50%,-120%);border:1px solid white}.end-b{background:#ac6920f5;transform:translate(-50%,30%)}.endpoint[hidden]{display:none}.block-label{position:absolute;pointer-events:none;font-size:10px;max-width:130px;background:#fff5df;color:#866427;padding:2px 6px;border:1px dashed #b6a586;border-radius:4px;transform:translate(-50%,-140%)}aside{min-width:0;overflow:auto;border-left:1px solid #d8e1d6;background:#fcfdf9;padding:23px 22px}.setup label{font-weight:600;font-size:12px}.setup select{width:100%;margin-top:6px;background:white;border:1px solid #c5d4c6;border-radius:7px;color:#2c5741;padding:8px}.setup p{font-size:11px;color:#83907c;margin:8px 0 15px}#groups{display:flex;gap:5px;flex-wrap:wrap;margin-bottom:16px}#groups button{font-size:11px;padding:5px 9px}#groups button.active{background:#28533e;color:white;border-color:#28533e}#detail{border:1px solid #d6e2d2;border-radius:10px;padding:15px;background:#fff}.detail-heading{display:flex;justify-content:space-between;font-size:11px;color:#87947e}#wire-id{font-weight:700;color:#3e7152}h2{font-size:18px;margin:6px 0 15px;line-height:1.5}.end-row{display:flex;gap:10px;align-items:flex-start}.end-row b{border-radius:50%;color:white;background:#285642;min-width:24px;height:24px;text-align:center}.end-row:last-of-type b{background:#ac6920}.end-row p{margin:0;overflow-wrap:anywhere}.connector{padding:4px 0 4px 34px;font-size:10px;color:#9caa92}#wire-note{font-size:12px;color:#71806b;margin:13px 0}.attention{font-size:11px;background:#fcf0d7;color:#8a6329;padding:9px;border-left:3px solid #c89544}.step-controls{display:flex;gap:8px;margin-top:15px}.step-controls button{flex:1;font-size:12px}.step-controls #next{background:#28533e;color:white}.toggles{margin:18px 0;font-size:12px}.toggles label{display:flex;align-items:center;gap:7px;margin:8px 0}.toggles input{accent-color:#326549}.toggles input[type=range]{width:100%}.toggles output{margin-left:auto}.toggles small{font-size:10px;color:#8b9681}details summary{font-size:12px;cursor:pointer;color:#54734d}#count{color:#a1aa97}#wire-list{margin:8px 0 18px}#wire-list button{display:block;width:100%;text-align:left;border:0;border-bottom:1px solid #e3e9dd;border-radius:0;padding:8px 4px;font-size:11px}#wire-list button.active{background:#e7efe2;color:#244b35;font-weight:600}#wire-list i{display:inline-block;width:8px;height:8px;border-radius:50%;margin-right:7px;vertical-align:middle}.limits{margin-top:18px;padding-top:14px;border-top:1px solid #d8e2d1}.limits ul{padding-left:18px}.limits li,.limits p{font-size:11px;color:#7a856d;margin:9px 0}.downloads{margin-top:22px}.downloads a{display:block;font-size:11px;color:#487443;padding:8px 0;border-bottom:1px solid #e0e6d9;text-decoration:none}.footer{font-size:10px;color:#8a947b;margin:18px 0 0}@media(max-width:850px){header{height:60px;padding:0 15px;gap:12px}header strong{font-size:13px}.brand{font-size:11px}.badge{font-size:9px;padding:4px 7px}main{height:auto;grid-template-columns:1fr}#stage{height:66vh;min-height:470px}aside{overflow:visible;border-top:1px solid #d8e1d6;border-left:0;padding:20px}.intro{top:18px;left:18px}.intro h1{font-size:24px}.intro p{font-size:10px}.views{max-width:96%;gap:0;bottom:15px}.views button{font-size:10px;padding:7px 8px}.stage-note{left:18px;bottom:66px;font-size:9px}.endpoint{font-size:10px;max-width:180px}.block-label{font-size:9px}}
.pin-label{position:absolute;pointer-events:none;font:bold 11px Consolas,monospace;color:white;padding:1px 4px;border:1px solid white;border-radius:3px;background:#345846;transform:translate(-50%,-50%)}.pin-V{background:#b94039}.pin-S{background:#b96a18}.pin-label[hidden]{display:none}.intro.closeup{background:#ffffffe6;border-radius:8px;padding:8px 12px}.intro.closeup h1{font-size:16px;margin:0}.intro.closeup span{display:none}.intro.closeup p{font-size:10px}

/* Compact classroom dock: one desktop row, two touch-friendly mobile rows. */
#stage{display:flex;flex-direction:column;min-height:0}#scene-area{position:relative;flex:1;min-height:0;overflow:hidden}
.connection-dock{position:relative;flex:none;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:6px 12px;padding:8px 14px;background:#fcfdf9;border-top:1px solid #d9e3d5}
.connection-heading{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
#component-connections{display:flex;align-items:center;flex-wrap:nowrap;gap:5px;min-width:0;max-width:100%}
#component-connections button:not(.quick-set){display:none}
.connection-dock #component-connections button.quick-set{display:flex;align-items:center;justify-content:center;gap:4px;flex:0 0 auto;min-height:34px;padding:5px 9px;font-size:12px;white-space:nowrap}
#component-connections button.active{background:#28533e;color:white;border-color:#28533e;box-shadow:0 0 0 1px #28533e}
.connection-count{font-size:10px;opacity:.72;min-width:10px;text-align:center}
#component-connections button[hidden]{display:none}
#more-connections{min-height:34px;min-width:0;width:164px;max-width:190px;border:1px solid #cfdbd1;border-radius:7px;padding:5px 24px 5px 9px;background:#fff;color:#2b5743;font-size:12px;cursor:pointer;text-overflow:ellipsis}
#more-connections.active{border-color:#28533e;background:#e8f0e4;color:#28533e}
.connection-dock .views{position:static;transform:none;flex:0 0 auto;justify-content:center;gap:2px;max-width:100%;width:fit-content;margin:0;padding:2px;box-shadow:none;background:#f1f5ee}
.connection-dock .views button{min-height:32px;padding:4px 9px;font-size:12px;white-space:nowrap}
.stage-note{bottom:10px;font-size:10px}.intro h1{font-size:26px}.intro{top:18px}
@media(max-width:850px){#stage{height:auto;min-height:0}#scene-area{flex:none;height:64vh;min-height:370px}.connection-dock{padding:8px 10px;justify-content:center;gap:6px 10px}.stage-note{bottom:10px}.intro h1{font-size:23px}}
@media(max-width:620px){#component-connections{width:100%;justify-content:center}.connection-dock #component-connections button.quick-set[data-wire-set="servo"],.connection-dock #component-connections button.quick-set[data-wire-set="driver"]{display:none}.connection-dock #component-connections button.quick-set{min-height:36px;padding:6px 10px}#more-connections{flex:1 1 auto;width:auto;max-width:190px;min-height:36px}.connection-dock .views button{min-height:34px;padding:5px 10px;font-size:11px}}