:root{font-family:Arial,Helvetica,sans-serif;color:#29362f;background:#f8f7f2;font-synthesis:none;--accent:#286e58;--soft:#e6eee6;--muted:#66726b;--line:#dedfd5}*{box-sizing:border-box}body{margin:0}button,select,input{font:inherit}button{cursor:pointer;color:inherit}button:focus-visible,select:focus-visible,input:focus-visible{outline:3px solid #4c9375;outline-offset:4px}button:disabled{opacity:.32;cursor:default}[hidden]{display:none!important}.site-header{height:100px;max-width:1600px;margin:auto;padding:0 5%;display:flex;align-items:center;justify-content:space-between;gap:24px;border-bottom:1px solid #e7e6dd}.site-title{font-size:25px;font-weight:500;letter-spacing:-.5px}.header-tools{display:flex;gap:14px;align-items:center}.icon-button{border:1px solid #d6dace;background:#fffef9;border-radius:8px;min-width:39px;height:39px;font-size:23px;display:inline-grid;place-items:center}.icon-button:hover,.secondary-button:hover{background:#eeeee5}#lesson{max-width:1660px;margin:auto;padding:25px 4% 40px}.lesson-heading{display:flex;align-items:center;justify-content:space-between;margin-bottom:23px;gap:20px}.text-button{border:0;padding:0;background:transparent;color:var(--muted);font-size:14px}.lesson-title-line{display:flex;align-items:center;gap:20px;margin-top:9px}.lesson-title-line h1{font-size:29px;letter-spacing:-.6px;font-weight:400;margin:0}.score-panel{display:flex;align-items:center;gap:20px;padding-left:25px}.score-panel>span{font-size:14px;color:var(--muted)}.score-panel strong{font-size:43px;color:var(--accent);font-weight:500;font-variant-numeric:tabular-nums}.score-panel small{font-size:23px;color:#839084}.lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 335px;gap:24px;align-items:start}.arena-shell{position:relative;background:#efede5;border:1px solid #d8d8cc;border-radius:13px;overflow:hidden}.arena-top{position:absolute;top:15px;left:18px;right:18px;z-index:2;display:flex;justify-content:flex-end;align-items:center;gap:8px}.view-controls{display:flex;border:1px solid #d7d8ce;background:#fffef8f0;border-radius:7px;padding:3px;box-shadow:0 2px 8px #3e46350a}.view-controls button{border:0;background:transparent;color:#526057;font-size:13px;padding:8px 11px;border-radius:4px}.view-controls button.active{color:#1b513c;background:#dcebdd}#arena{height:clamp(390px,49vh,590px);min-height:390px}#arena canvas{display:block;width:100%;height:100%;touch-action:none}.arena-help{font-size:12px;color:#667065;position:absolute;bottom:13px;left:18px;right:18px;display:flex;justify-content:space-between;pointer-events:none}.arena-help>span{font-size:11px}.award{pointer-events:none;position:absolute;top:72px;left:50%;transform:translate(-50%,8px) scale(.85);opacity:0;background:#fffefa;color:#216546;font-size:30px;font-weight:600;padding:10px 24px;border:1px solid #9fc4a7;border-radius:30px;box-shadow:0 5px 24px #244b3520;transition:opacity .2s,transform .3s;white-space:nowrap;z-index:4}.award.show{opacity:1;transform:translate(-50%,0) scale(1)}#score-burst{position:absolute;left:50%;top:100px;pointer-events:none;z-index:3}.spark{position:absolute;width:6px;height:6px;border-radius:2px;background:var(--spark);animation:spark-out .9s cubic-bezier(.1,.5,.3,1) forwards}0%{transform:translate(0,0) scale(.5);opacity:1}70%{opacity:1}100%{transform:translate(var(--dx),var(--dy)) rotate(var(--spin));opacity:0}.score-pop{animation:score-pop .5s ease-out}0%,100%{transform:scale(1)}40%{transform:scale(1.2)}.finished{position:absolute;bottom:42px;left:50%;transform:translateX(-50%);background:#fffdf4f5;border:1px solid #99bfa4;border-radius:11px;padding:14px 22px;display:flex;align-items:center;gap:14px;white-space:nowrap;box-shadow:0 5px 16px #4f523410}.finished>span{display:grid;place-items:center;background:#d9ead8;color:#286e48;width:34px;height:34px;border-radius:50%;font-size:23px}.finished strong{font-size:18px;color:#295f43;font-weight:500}.finished p{font-size:13px;color:var(--muted);margin:4px 0 0}.playback{padding:16px 0 12px}.playback-main{display:flex;align-items:center;gap:8px}.primary-button,.secondary-button{border-radius:7px;font-size:14px;font-weight:500;height:39px;padding:0 16px;white-space:nowrap}.primary-button{background:var(--accent);color:#fffefa;border:1px solid var(--accent);min-width:139px}.primary-button:hover{filter:brightness(1.08)}.secondary-button{background:#fffef9;border:1px solid #cdd3c7}.control-separator{width:1px;background:#d3d7cd;height:24px;margin:0 5px}.speed-label{margin-left:auto;display:flex;align-items:center;gap:8px;font-size:13px;color:var(--muted)}select{font-size:13px;padding:7px;background:#fffef9;border:1px solid #cdd3c7;border-radius:6px;color:#3c493e}.timeline-row{display:flex;align-items:center;gap:12px;font-size:12px;color:var(--muted);margin-top:13px;font-variant-numeric:tabular-nums}.timeline-row input{flex:1;min-width:0;accent-color:var(--accent);height:4px;cursor:pointer}.instruction-card{display:flex;gap:20px;padding:19px 20px;border:1px solid var(--line);border-radius:10px;background:#fffef9;min-height:109px}.instruction-card>span{color:var(--accent);font-size:12px;line-height:1.7;white-space:nowrap;padding-top:1px}.instruction-card h2{font-size:18px;font-weight:500;margin:0 0 7px}.instruction-card p{font-size:16px;line-height:1.6;color:#5c685e;margin:0}.steps-panel{background:#fffef9;border:1px solid var(--line);border-radius:12px;overflow:hidden}.steps-panel-heading{padding:23px 21px}.steps-panel-heading>span,.steps-panel-heading>p{display:none}.steps-panel-heading h2{font-size:22px;font-weight:400;letter-spacing:-.3px;margin:0}.step{border:0;border-top:1px solid #e4e7dd;background:transparent;text-align:left;width:100%;display:flex;align-items:center;gap:12px;padding:14px 17px;position:relative;min-height:62px}.step:hover{background:#f0f3e9}.step.active{background:#eaf1e5}.step.active:before{content:'';position:absolute;left:0;top:0;bottom:0;width:3px;background:var(--accent)}.step-index{flex-shrink:0;display:grid;place-items:center;width:25px;height:25px;border:1px solid #bfcbbd;color:#61745e;border-radius:50%;font-size:12px}.step.done .step-index{background:#deecda;border-color:#9db68e;color:#3e6b34}.step-label{font-size:14px;line-height:1.5;color:#3e4a40}.step-points{margin-left:auto;color:#347148;font-size:15px;white-space:nowrap}.rubric-note{padding:17px 21px;font-size:13px;line-height:1.6;color:#657261;background:#f5f5ed;border-top:1px solid var(--line)}.rubric-note strong{color:#3e523d;font-weight:500}#canvas-fallback{padding:120px 30px;font-size:18px;color:#493f31}body.edison{--accent:#965327;--soft:#f3e8d9}.edison .view-controls button.active{background:#f3e2ca;color:#78461f}.edison .step.active{background:#f5ecdc}.edison .step.done .step-index{background:#f1e3cc;color:#86572c;border-color:#c7ac86}.edison .finished{border-color:#c6a77d}.edison .finished strong{color:#7e5626}.edison .finished>span{background:#f1dfc0;color:#7e5626}
@media(max-width:1150px){.lesson-layout{grid-template-columns:minmax(0,1fr) 290px;gap:17px}#lesson{padding-left:3%;padding-right:3%}.playback-main{gap:5px;flex-wrap:wrap}.primary-button,.secondary-button{padding:0 11px}.speed-label{gap:4px}.control-separator{margin:0 2px}}
@media(max-width:900px){.site-header{height:82px}.lesson-layout{grid-template-columns:1fr}.steps-panel{margin-top:5px}#steps{display:grid;grid-template-columns:1fr 1fr}.step:nth-child(odd){border-right:1px solid var(--line)}#arena{height:480px}}
@media(max-width:620px){.site-header{padding:0 6%;height:78px}.site-title{font-size:21px}.header-tools{gap:7px}.lesson-title-line h1{font-size:25px}.lesson-heading{margin-bottom:16px}.score-panel{padding-left:8px;gap:8px}.score-panel>span{font-size:12px}.score-panel strong{font-size:32px}.score-panel small{font-size:18px}#arena{height:380px;min-height:380px}.arena-help{font-size:10px;left:10px;right:10px}.arena-help>span{display:none}.arena-top{right:10px;top:10px}.view-controls button{font-size:12px;padding:7px 9px}.playback-main{flex-wrap:wrap;gap:6px}.speed-label{font-size:12px}.primary-button{min-width:116px}.icon-button{min-width:33px;height:36px}.primary-button,.secondary-button{height:36px;font-size:13px;padding:0 10px}.control-separator{display:none}.instruction-card{padding:16px 12px;gap:12px}.instruction-card p{font-size:15px}#steps{grid-template-columns:1fr}.step:nth-child(odd){border-right:0}.finished{padding:12px;max-width:95%;white-space:normal;width:310px}.finished strong{font-size:16px}.award{font-size:25px;max-width:95%;white-space:normal;text-align:center}}
@media(prefers-reduced-motion:reduce){.award{transition:none}.spark,.score-pop{animation:none}.spark{display:none}}


.header-control{display:inline-flex;align-items:center;justify-content:center;gap:9px;min-height:44px;padding:10px 14px;border:1px solid #cdd3c7;border-radius:10px;background:#fffef9;font-size:13px;font-weight:500;white-space:nowrap;transition:background .18s,border-color .18s}
.header-control:hover{background:#eeeee5;border-color:#96a795}
.header-control svg{width:21px;height:21px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round;flex-shrink:0}
#sound[aria-pressed="true"]{background:#e6eee6;color:#286e58;border-color:#b6cbb9}
.sound-indicator{width:6px;height:6px;border-radius:50%;background:#286e58}
#sound[aria-pressed="false"] .sound-indicator{background:#9b9e96}
.sound-slash,.collapse-icon{display:none}
#sound[aria-pressed="false"] .sound-waves{display:none}
#sound[aria-pressed="false"] .sound-slash{display:block}
#fullscreen[aria-pressed="true"] .expand-icon{display:none}
#fullscreen[aria-pressed="true"] .collapse-icon{display:block}
@media(max-width:620px){.header-control{padding:9px;gap:6px}.header-control .control-label,.sound-indicator{display:none}}


#finish-fireworks{position:absolute;inset:0;overflow:hidden;pointer-events:none;z-index:3}
.firework-burst{position:absolute}
.firework-burst i{position:absolute;width:7px;height:7px;border-radius:50%;background:var(--color);box-shadow:0 0 7px var(--color);opacity:0;animation:finish-firework 2s var(--delay) cubic-bezier(.12,.6,.25,1) both}0%{opacity:0;transform:translate(0,45px) scale(.3)}12%{opacity:1;transform:translate(0,0) scale(1.1)}65%{opacity:1}100%{opacity:0;transform:translate(var(--fx),calc(var(--fy) + 45px)) scale(.2)}.firework-burst i{animation:finish-glow 1.5s var(--delay) ease both;transform:translate(var(--fx),var(--fy))}0%,100%{opacity:0}40%{opacity:.7}
/* Task brief */
.task-intro{padding:30px 0 34px;border-bottom:1px solid var(--line);margin-bottom:28px}
.eyebrow{margin:0 0 10px;font-size:12px;letter-spacing:.12em;color:var(--accent);font-weight:600}
.task-intro h1{font-size:38px;font-weight:400;letter-spacing:-.8px;margin:0 0 12px}
.task-lead{font-size:19px;line-height:1.55;color:#4a564c;margin:0 0 22px;max-width:860px}
.task-facts{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}
.task-facts div{background:#fffef9;border:1px solid var(--line);border-radius:10px;padding:14px 16px;display:flex;flex-direction:column;gap:5px}
.task-facts b{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);font-weight:600}
.task-facts span{font-size:15px;line-height:1.5;color:#3e4a40}
.lesson-title-line h2{font-size:24px;letter-spacing:-.4px;font-weight:400;margin:0}
@media(max-width:900px){.task-facts{grid-template-columns:1fr 1fr}.task-intro h1{font-size:32px}}
@media(max-width:620px){.task-facts{grid-template-columns:1fr}.task-intro{padding:22px 0 24px}.task-intro h1{font-size:28px}.task-lead{font-size:17px}.lesson-title-line h2{font-size:20px}}
.score-panel strong{white-space:nowrap}