@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;600;700;800&display=swap');
:root{font-family:'Noto Sans SC',system-ui,sans-serif;color:#253e35;background:#f7f8f2;font-synthesis:none;--green:#317b63;--muted:#76847a}*{box-sizing:border-box}body{margin:0}button,a,input{-webkit-tap-highlight-color:transparent}button{font:inherit;cursor:pointer;border:0;transition:transform .15s,background .15s}button:hover{transform:translateY(-2px)}button:disabled{opacity:.45;cursor:default;transform:none}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #e3ac42;outline-offset:4px}header{max-width:1120px;margin:auto;padding:26px 30px;display:flex;justify-content:space-between;align-items:center}.brand{text-decoration:none;color:#253e35;font-size:21px;font-weight:800;display:flex;align-items:center;gap:10px}.brand-icon{display:grid;place-items:center;background:var(--green);color:#fff;width:38px;height:38px;border-radius:13px;font-size:30px}.quiet{background:transparent;color:#60776a;font-size:14px;padding:12px;border-radius:12px}main{max-width:1000px;margin:30px auto 55px;padding:0 28px}.intro{display:flex;justify-content:space-between;align-items:center;margin-bottom:30px}.eyebrow{font-size:12px;letter-spacing:2px;color:var(--green);font-weight:700}.intro h1{font-size:38px;letter-spacing:-1.5px;margin:12px 0}.intro p{color:var(--muted);font-size:15px;line-height:1.9}.art{width:200px;height:150px;position:relative;flex-shrink:0}.tile{position:absolute;display:grid;place-items:center;font-size:55px;font-weight:700;width:85px;height:85px;border-radius:25px;box-shadow:0 8px 0 #00000005}.tile.one{background:#f4d77b;left:0;top:0;transform:rotate(-12deg)}.tile.two{background:#a8cebb;left:92px;top:35px;transform:rotate(12deg)}.art small{position:absolute;bottom:0;left:48px;color:#df9e56;font-size:30px}.panel{background:#fff;border:1px solid #e5e9df;border-radius:26px;padding:30px;box-shadow:0 8px 32px #294e3510}.section-title{display:flex;align-items:center;gap:10px;font-size:17px;font-weight:700;margin-bottom:18px}.step{background:#eef4ed;color:var(--green);font-size:12px;border-radius:8px;padding:5px 9px}.operations{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-bottom:30px}.operation{border:2px solid transparent;border-radius:18px;padding:22px 12px;background:#f5f7f2;color:#52635a;display:flex;align-items:center;justify-content:center;gap:13px;font-weight:600}.operation .symbol{font-size:32px;font-weight:500}.operation.selected{background:#eef7f0;border-color:var(--green);color:var(--green)}.levels{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.level{text-align:left;border:1.5px solid #e4e9e1;background:#fff;border-radius:15px;padding:17px 14px;color:#506257;min-height:104px}.level.selected{border-color:var(--green);background:#f3f8f1}.level strong{display:block;font-size:16px;margin:7px 0}.level small{display:block;font-size:11px;line-height:1.7;color:var(--muted)}.dots{letter-spacing:3px;color:#c4cdc1;font-size:11px}.dots b{color:var(--green)}.start-row{margin-top:28px;padding-top:24px;border-top:1px dashed #dce4d9;display:flex;justify-content:space-between;align-items:center;gap:20px}.hint{font-size:13px;color:var(--muted);line-height:1.9}.primary{background:var(--green);color:white;border-radius:13px;padding:16px 30px;font-weight:700}.secondary{background:#edf2e9;color:#365a46;padding:14px 22px;border-radius:13px}.features{display:flex;justify-content:center;gap:36px;font-size:13px;color:#819080;margin-top:25px}footer{max-width:1056px;margin:auto;padding:24px 30px;color:#8b968b;font-size:12px;border-top:1px solid #e5e9df;display:flex;justify-content:space-between}.practice{max-width:650px;margin:auto}.practice-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:18px}.badge{background:#eaf1e8;padding:8px 12px;border-radius:9px;font-size:13px;color:#56725c}.progress{height:7px;border-radius:9px;background:#e9eee4;overflow:hidden;margin-bottom:25px}.progress i{height:100%;background:#77ac8d;display:block;transition:width .3s}.question-panel{text-align:center}.question-caption{font-size:13px;color:var(--muted)}.equation{font-size:clamp(28px,5vw,46px);font-weight:700;margin:30px 0 22px;display:flex;justify-content:center;align-items:center;gap:12px}.answer{font:inherit;color:var(--green);width:135px;min-width:0;text-align:center;border:2px solid #b6ceba;border-radius:14px;background:#f6f9f1;padding:10px 3px}.feedback{min-height:54px;font-size:15px;line-height:1.7;color:#66816d}.feedback.wrong{color:#ae762b}.feedback.correct{color:var(--green)}.keypad{max-width:330px;margin:0 auto 20px;display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.keypad button{background:#f1f4ec;border:1px solid #e3e9dd;border-bottom:3px solid #dce4d6;border-radius:13px;min-height:57px;font-size:23px;color:#344f3f}.keypad button.utility{font-size:14px;color:#7a887b}.wide{width:100%;max-width:330px}.result{text-align:center}.medal{font-size:50px}.result h1{font-size:28px;margin:12px 0}.score{font-size:76px;font-weight:800;color:var(--green);line-height:1.3}.score small{font-size:16px;color:var(--muted);font-weight:400}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:24px 0}.stat{padding:18px 5px;background:#f4f7ef;border-radius:14px;font-size:12px;color:#7b887c}.stat b{display:block;font-size:25px;color:#345b43;margin-bottom:7px}.result-actions{display:flex;gap:12px;justify-content:center}.review{margin-top:26px}.review h2{font-size:18px}.review-row{display:flex;justify-content:space-between;gap:10px;border-top:1px solid #edf0e8;padding:16px 0;align-items:center;font-size:15px}.review-row small{display:block;color:#8b9589;font-size:12px;margin-top:5px}.points{color:var(--green);font-size:13px;white-space:nowrap}dialog{border:0;border-radius:24px;padding:28px;max-width:calc(100% - 36px);color:#344f3f;box-shadow:0 20px 80px #0002}dialog::backdrop{background:#243e3266}dialog h2{font-size:21px}dialog p{font-size:14px;color:var(--muted);line-height:1.8}.dialog-actions{display:flex;gap:12px;margin-top:25px}@media(max-width:620px){header{padding:18px}.brand{font-size:17px}.quiet{font-size:12px;padding:8px}main{margin:18px auto 32px;padding:0 16px}.intro h1{font-size:29px}.intro p{font-size:13px}.art{width:100px;height:120px;transform:scale(.65);transform-origin:right center;margin-left:-30px}.panel{padding:22px 16px;border-radius:22px}.operations{gap:8px}.operation{padding:15px 5px;flex-direction:column;gap:2px;font-size:13px}.levels{grid-template-columns:repeat(2,1fr)}.level{min-height:90px}.start-row{flex-direction:column;align-items:stretch;gap:12px}.start-row .hint{text-align:center}.features{gap:16px;font-size:11px}footer{padding:20px;justify-content:center}footer span{display:none}.equation{gap:8px}.answer{width:110px}.result-actions button{padding:14px 20px}.question-panel{padding-top:26px}}

@media(max-width:620px){.stats{grid-template-columns:repeat(2,1fr)}}