:root{font-family:system-ui,-apple-system,'Apple SD Gothic Neo',sans-serif;color:#20362e;background:#f4f7f2;font-size:15px}*{box-sizing:border-box}body{margin:0;padding:24px}header{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:20px}h1{font-size:27px;letter-spacing:-1px;margin:0}h2{font-size:19px;margin-top:0}p{line-height:1.65}.muted{color:#64756c;font-size:13px}.panel{background:white;border:1px solid #dce6da;border-radius:18px;padding:22px;margin-bottom:18px;box-shadow:0 6px 22px #193c2210}.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.grow{flex:1}label{display:block;font-size:13px;line-height:1.6}input,select,textarea,button{font:inherit;border-radius:10px;border:1px solid #bccdbd;padding:10px;background:#fff;color:inherit}input[type=number]{width:85px}input[type=checkbox]{width:auto}textarea{width:100%;min-height:110px;line-height:1.6}button{cursor:pointer;background:#edf3e9;font-weight:650}button.primary{background:#246d49;color:white;border-color:#246d49}button.danger{color:#a12f2f;background:#fff3f1}button:disabled{opacity:.5;cursor:wait}button:hover:enabled{filter:brightness(.96)}.toolbar{margin:14px 0;display:flex;gap:10px;align-items:center;flex-wrap:wrap}.notice{padding:12px 16px;border-radius:12px;background:#fff4d3;margin-bottom:16px;white-space:pre-wrap;line-height:1.6}.error{background:#ffe6e3;color:#8e2626}.hidden{display:none!important}.board{min-width:280px}.blackboard{text-align:center;background:#234e3e;color:#fff;padding:11px;border-radius:8px;margin:12px auto;width:70%;letter-spacing:8px;font-size:14px}.rear{text-align:center;color:#849285;font-size:12px;margin:12px}.seats{display:grid;gap:9px}.seat{min-height:88px;background:#f4f6f1;border:1px solid #dce4d8;border-radius:12px;padding:9px;text-align:center;display:flex;flex-direction:column;justify-content:center;overflow-wrap:anywhere}.seat .number{font-size:12px;color:#72806c}.seat strong{font-size:18px;margin:4px 0}.seat .studentId{font-size:12px;color:#677564}.seat.mine{background:#fff0b7;border:3px solid #d89e19}.seat.filled{background:#e7f2e4}.seat.mine.filled{background:#fff0b7}.seat.pairEdge{border-right:4px solid #b5c5ae}.seat.flash{animation:pop .65s ease-out}.stats{font-size:16px;color:#35694b}.big-result{text-align:center;font-size:64px;font-weight:800;color:#246d49;margin:18px}.scroll{overflow:auto}table{border-collapse:collapse;width:100%;font-size:13px}th,td{text-align:left;padding:8px;border-bottom:1px solid #e0e7dd}th{background:#f4f7f1}td input[type=number]{width:65px;padding:6px}.grid2{display:grid;grid-template-columns:1fr 1fr;gap:18px}#qr img,#qr canvas{margin:12px auto}.particle{position:fixed;width:10px;height:10px;pointer-events:none;z-index:9999;animation:confetti .8s ease-out forwards}@keyframes pop{0%{transform:scale(.8);background:#ffe194}65%{transform:scale(1.06)}100%{transform:scale(1)}}@keyframes confetti{from{transform:translate(0,0) rotate(0);opacity:1}to{transform:translate(var(--dx),var(--dy)) rotate(270deg);opacity:0}}@media(max-width:650px){body{padding:14px}.panel{padding:15px}.grid2{grid-template-columns:1fr}.seat{min-height:75px;padding:5px}.seat strong{font-size:15px}.seats{gap:5px}h1{font-size:23px}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important}}

a{color:#246d49}a.button{display:inline-block;padding:10px;border-radius:10px;border:1px solid #bccdbd;text-decoration:none}
.login-panel{max-width:440px;margin:10vh auto}.login-panel input{width:100%}.login-panel label{margin-bottom:18px}
.seat.mine strong::after{content:" · 내 자리";font-size:12px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}
@media(min-width:1200px){body{max-width:1500px;margin:auto}.seats .seat{min-height:100px}}


/* Initial HTML stays closed even before scripts run or when JavaScript is disabled. */
#teacherContent[hidden],#authGate[hidden],#authRetry[hidden]{display:none!important}

[data-feature-panel][hidden],[hidden]{display:none!important}.feature-tabs{display:flex;gap:8px;margin:16px 0}.feature-tabs button{flex:1;padding:14px}.feature-tabs [aria-selected=true]{background:#246d49;color:white;border:2px solid #123e2b}.feature-tabs [aria-selected=true]::before{content:"✓ "}.cleaning-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:12px}.cleaning-zone{margin:0}.cleaning-zone ul{padding-left:20px}.cleaning-member{padding:8px 0}.cleaning-member.mine,.my-zone{border:2px solid #ad7b12;background:#fff6d5}.my-label{font-weight:bold}.participant-list{display:flex;gap:12px;flex-wrap:wrap}.zone-editor{border:1px solid #c6d6c3;border-radius:10px;padding:14px;margin:12px 0}pre{white-space:pre-wrap;overflow-wrap:anywhere}.notice:empty{display:none}.big-result{overflow-wrap:anywhere}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #ba7b0a;outline-offset:3px}@media(max-width:650px){.big-result{font-size:38px}.cleaning-grid{grid-template-columns:1fr}.feature-tabs button{font-size:14px;padding:12px 8px}}