*{box-sizing:border-box}body{font-family:Inter,Segoe UI,Roboto,Arial,sans-serif;margin:0;color:#1b1b1b;background:#fbfbfb}
.wrap{max-width:980px;margin:22px auto;padding:18px}
h1{font-size:20px;margin:6px 0 14px;text-align:center}
.controls{background:#fff;border:1px solid #e6e6e6;padding:12px;border-radius:8px;box-shadow:0 2px 6px rgba(16,24,40,.04)}
.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center;justify-content:center;margin-bottom:8px}
label{font-size:14px;color:#333}
input[type=number]{width:86px;padding:6px;border-radius:6px;border:1px solid #ccc}
select{padding:6px;border-radius:6px;border:1px solid #ccc}
button{padding:8px 12px;border-radius:8px;border:1px solid #2b6cb0;background:#2b6cb0;color:#fff;cursor:pointer}
button[disabled]{opacity:.45;cursor:not-allowed}
.number-line{position:relative;margin:22px auto 6px;width:100%;height:90px;background:linear-gradient(#fff,#fff);display:flex;align-items:flex-end;justify-content:space-between;padding:18px;border-radius:8px;border:1px solid #e8e8e8}
.cell{flex:1;text-align:center;position:relative;height:100%}
.tick{width:2px;height:22px;background:#666;margin:0 auto 6px;border-radius:2px}
.label{font-size:13px;color:#333}
.cell.marked{outline:3px solid rgba(59,130,246,.12);box-shadow:0 4px 8px rgba(59,130,246,.06)}
.apple{position:absolute;top:6px;width:46px;height:46px;transition:left 350ms cubic-bezier(.22,.9,.32,1),transform 350ms ease,filter 350ms ease;pointer-events:none}
.equation{font-weight:600;margin-top:6px;text-align:center}
.status{color:#444;margin-top:6px;text-align:center;font-size:14px}
.footer{margin-top:12px;text-align:center;color:#666;font-size:13px}
@media (max-width:640px){.apple{width:38px;height:38px}.controls .row{flex-direction:column}}