:root{font-family:system-ui,sans-serif;color:#192c31;background:#f2f5f4;font-size:18px}*{box-sizing:border-box}body{margin:0}main{max-width:780px;margin:auto;padding:24px}header{display:flex;align-items:center;justify-content:space-between;gap:12px}h1{font-size:1.6rem;line-height:1.25}p{line-height:1.6}.stage{background:white;border:1px solid #baccc8;border-radius:12px;padding:20px;margin:20px 0}.row{display:flex;gap:8px;flex-wrap:nowrap;height:32px}.piece{font-family:Arial,sans-serif;font-size:28px;line-height:30px;color:#192c31}label{display:block;margin-top:18px;font-weight:600}input{display:block;width:100%;max-width:260px;font:inherit;padding:12px;margin-top:8px;border:2px solid #647b75;border-radius:6px}button{font:inherit;padding:12px 16px;min-height:48px;border:1px solid #255e50;border-radius:8px;background:#255e50;color:white;cursor:pointer}button:disabled{opacity:.65;cursor:default}#status{border-left:4px solid #255e50;padding:12px;background:white}#exit,#reload{background:white;color:#255e50}#reload{margin-bottom:20px}[hidden]{display:none!important}@media(max-width:450px){main{padding:16px}header{font-size:.8rem}.stage{padding:16px}h1{font-size:1.4rem}}
#signin{margin-top:20px}#login{background:white;border:1px solid #baccc8;padding:24px;border-radius:12px;max-width:520px}#login input{max-width:100%}#activity{background:white;padding:24px;border-radius:12px}