:root{font-family:Arial,sans-serif;color:#1b1f2a;background:#fff;line-height:1.5;letter-spacing:0}
*{box-sizing:border-box}body{margin:0;overflow-wrap:anywhere}button,input,select{font:inherit}button,input,select,textarea{max-width:100%}button,select{cursor:pointer}
a{color:#176b87}button{padding:10px 18px;border:1px solid #c9d6df;border-radius:4px;background:#fff;font-weight:700;color:inherit}
button.primary{background:#176b87;color:white;border-color:#176b87}button:disabled{opacity:.5;cursor:default}
:focus-visible{outline:3px solid #0b63ce;outline-offset:3px}[hidden]{display:none!important}
.breadcrumbs{padding:12px 24px;border-bottom:1px solid #d9dee8;display:flex;flex-wrap:wrap;gap:8px}
main{max-width:1080px;margin:0 auto;padding:22px 24px}h1{font-size:2rem;color:#176b87;margin:0 0 4px}h2{font-size:1.3rem;margin:0}
.parts{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin:16px 0}.part{display:grid;gap:8px;border:1px solid #d9dee8;border-top:4px solid #176b87;padding:16px;text-decoration:none;color:inherit}.part:nth-child(2){border-top-color:#288446}.part:hover{background:#eef8fb}.part svg{width:100%;height:90px}.part strong{font-size:1.25rem}.part span{color:#5f6675}.part-navigation{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;margin:14px 0}.part-navigation strong{font-size:1.2rem}
.prototype-note{font-size:.85rem;color:#5f6675;margin:0 0 20px}.settings,.actions,.status{display:flex;align-items:center;flex-wrap:wrap;gap:14px}
.settings{padding:12px 0;border-bottom:1px solid #d9dee8}.settings label{display:flex;align-items:center;gap:8px}select{padding:8px;border:1px solid #9fb3c8;border-radius:4px}
.status{padding:14px 0;justify-content:space-between;font-variant-numeric:tabular-nums}#lives{color:#c53645;font-size:1.6rem;white-space:nowrap}
.task{border-left:5px solid #176b87;background:#eef8fb;padding:18px 24px;margin:12px 0 20px}.task p{margin:0 0 8px}
#expression{font-size:2.5rem;font-weight:700;line-height:1.5;overflow-wrap:anywhere;min-height:1.5em}#hint{margin:10px 0 0;border-top:1px solid #bdd6df;padding:12px 0 0;font-size:1rem}#hint ul{margin:0;padding-left:22px}
#answer{width:8ch;padding:10px;border:2px solid #176b87;background:#f4fbfd;border-radius:4px;font-size:1.6rem;font-weight:700}
#number-answer{display:flex;align-items:center;gap:10px}.divisors{display:flex;flex-wrap:wrap;gap:10px;margin:12px 0}
.divisors label{display:flex;align-items:center;justify-content:center;gap:10px;border:1px solid #9fb3c8;padding:12px;min-width:70px;border-radius:4px;cursor:pointer}
.divisors label:has(:checked){background:#eaf6f8;border-color:#176b87}.divisors input{width:20px;height:20px;accent-color:#176b87}
fieldset{border:0;padding:0;margin:0}legend{font-weight:700}#feedback{margin:18px 0;padding:12px 16px;min-height:3.4em;font-size:1.3rem;font-weight:700;background:#f4f6f8;border-left:4px solid #9fb3c8;overflow-wrap:anywhere}
#feedback.good{background:#edf8f0;border-color:#288446}#feedback.bad{background:#fff3f2;border-color:#bd3434}
.secondary{display:flex;gap:20px;flex-wrap:wrap;margin:18px 0}.secondary button{border:0;padding:5px;color:#176b87}
#summary{border-top:3px solid #288446;padding:20px 0;margin-top:20px}#summary-text{font-size:1.2rem}.results{padding-left:24px;overflow-wrap:anywhere}.results li{padding:6px 0}
footer{padding:20px 24px;border-top:1px solid #d9dee8;display:flex;flex-wrap:wrap;gap:24px;font-size:.9rem}
@media(max-width:600px){main{padding:16px}.breadcrumbs{padding:10px 16px}h1{font-size:1.6rem}#expression{font-size:1.8rem}.task{padding:14px}select{width:100%}.settings label:first-child{flex-basis:100%;flex-direction:column;align-items:stretch;gap:4px}.status{gap:4px;font-size:.9rem}.actions{gap:10px}button{padding:10px 13px}#feedback{font-size:1.1rem}.divisors{gap:8px}}
@media print{.settings,.actions,.secondary,footer,.breadcrumbs{display:none}main{max-width:none}}
@media(max-width:600px){.parts{grid-template-columns:1fr}.part{padding:12px}.part svg{height:65px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important;scroll-behavior:auto!important}}