:root{
  --ink:#14181d; --paper:#fafbf8; --card:#ffffff;
  --rule:#e2e6dd; --rule-strong:#c8cfc2;
  --green:#1f8a4c; --green-dim:#e8f3ec;
  --amber:#ffc000; --slate:#5a6472; --faint:#8b93a1;
  --danger:#b4451f;
  --mono:ui-monospace,"SFMono-Regular",Consolas,"D2Coding",monospace;
  --sans:-apple-system,BlinkMacSystemFont,"Segoe UI","Pretendard","Malgun Gothic",sans-serif;
}
*{box-sizing:border-box}
body{
  margin:0; font-family:var(--sans); color:var(--ink); background:var(--paper);
  background-image:linear-gradient(var(--rule) 1px, transparent 1px),linear-gradient(90deg, var(--rule) 1px, transparent 1px);
  background-size:28px 22px;
}
.wrap{max-width:760px;margin:0 auto;padding:40px 20px 80px}
h1{font-size:26px;font-weight:800;letter-spacing:-.02em;margin:0 0 6px}
.sub{color:var(--slate);font-size:14px;margin:0 0 24px}
.panel{background:var(--card);border:1px solid var(--rule-strong);border-radius:6px;padding:22px;margin-top:18px}
.panel h2{font-size:13px;letter-spacing:.06em;text-transform:uppercase;color:var(--slate);margin:0 0 14px;font-weight:700;font-family:var(--mono)}
label{display:block;font-size:13px;color:var(--slate);margin:12px 0 5px;font-weight:600}
input,select{width:100%;padding:10px 12px;border:1px solid var(--rule-strong);border-radius:5px;font-size:14px;font-family:var(--sans);background:#fff}
button{margin-top:16px;width:100%;padding:13px;border:0;border-radius:5px;background:var(--ink);color:#fff;font-size:14.5px;font-weight:700;cursor:pointer}
button:hover{background:var(--green)}
button.secondary{background:#fff;color:var(--ink);border:1px solid var(--rule-strong)}
button.secondary:hover{background:var(--green-dim);color:var(--green)}
.err{background:#fdf0eb;border:1px solid #eccbbc;color:var(--danger);padding:12px 14px;border-radius:5px;font-size:13.5px;margin-top:14px}
.ok{background:var(--green-dim);border:1px solid #bfe0cd;color:var(--green);padding:12px 14px;border-radius:5px;font-size:13.5px;margin-top:14px}
table{width:100%;border-collapse:collapse;font-size:13.5px}
th,td{text-align:left;padding:8px 10px;border-bottom:1px solid var(--rule)}
th{color:var(--faint);font:600 11px var(--mono);text-transform:uppercase;letter-spacing:.05em}
.row{display:flex;gap:10px;align-items:center;justify-content:space-between;padding:10px 0;border-top:1px solid var(--rule)}
.row:first-child{border-top:0}
.tag{font:600 11px var(--mono);padding:3px 7px;border-radius:3px;background:#f2f4ef;border:1px solid var(--rule);color:var(--slate)}
.topbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:6px}
.topbar span{font-size:13px;color:var(--slate)}
.topbar a{font-size:13px;color:var(--slate);cursor:pointer;text-decoration:underline}
.grid3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:12px}
.hidden{display:none}

/* drag & drop zone (모범답안 업로드) */
#modelDrop{
  border:2px dashed var(--rule-strong); border-radius:6px; background:#fdfefc;
  padding:34px 20px; text-align:center; cursor:pointer; transition:.14s; margin-top:14px;
}
#modelDrop:hover,#modelDrop.hot{border-color:var(--green); background:var(--green-dim)}
#modelDrop .big{font-size:14.5px;font-weight:600}
#modelDrop .small{color:var(--faint);font-size:12.5px;margin-top:5px}
.detected-row{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:9px 0;border-top:1px solid var(--rule)}
.detected-row:first-child{border-top:0}
.detected-row .fn{font-size:13px;word-break:break-all}
.detected-row select{width:auto;padding:6px 8px;font-size:13px}

/* 년도 > 월 > 형 드릴다운 브라우저 */
.drill{display:flex;gap:10px;flex-wrap:wrap}
.drill select{width:auto;min-width:110px}

/* 학생 고르기 (현황판) */
.picker{position:relative}
.picker input{width:100%}
.picker-menu{
  position:absolute; z-index:20; left:0; right:0; top:calc(100% + 4px);
  background:#fff; border:1px solid var(--rule-strong); border-radius:5px;
  max-height:230px; overflow:auto; box-shadow:0 6px 18px rgba(20,24,29,.10);
}
.picker-menu div{padding:9px 12px;font-size:13.5px;cursor:pointer}
.picker-menu div:hover,.picker-menu div.active{background:var(--green-dim);color:var(--green)}
.picker-menu .none{color:var(--faint);cursor:default}
.picker-menu .none:hover{background:#fff;color:var(--faint)}
.chips{display:flex;flex-wrap:wrap;gap:7px;margin-top:11px}
.chip{
  display:inline-flex;align-items:center;gap:7px;font-size:13px;font-weight:600;
  background:var(--green-dim);border:1px solid #bfe0cd;color:var(--green);
  padding:5px 6px 5px 11px;border-radius:14px;
}
.chip b{font-weight:700}
.chip .x{cursor:pointer;font-size:15px;line-height:1;color:var(--green);opacity:.6;padding:0 3px}
.chip .x:hover{opacity:1}
.dup{font:600 10.5px var(--mono);background:var(--amber);color:#3a2c00;border-radius:8px;padding:1px 5px;margin-left:5px}

/* 학생 플로팅 문제창 (Document PiP 또는 화면 고정 폴백 둘 다 이 스타일을 씀) */
#problem-panel{font-family:var(--sans);color:var(--ink);background:var(--paper);font-size:13.5px}
#problem-panel.pp-fallback{
  position:fixed; right:16px; bottom:16px; width:380px; height:520px; max-width:92vw; max-height:88vh;
  min-width:280px; min-height:120px; overflow:auto; resize:both;
  border:1px solid var(--rule-strong); border-radius:8px; box-shadow:0 10px 30px rgba(20,24,29,.18); z-index:9999;
  background:var(--card);
}
#problem-panel .pp-header{display:flex;justify-content:space-between;align-items:center;gap:8px;padding:10px 12px;background:var(--ink);color:#fff;border-radius:8px 8px 0 0;position:sticky;top:0}
#problem-panel .pp-title{font-weight:700;font-size:0.95em;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
#problem-panel .pp-controls{display:flex;gap:4px;flex-shrink:0}
#problem-panel .pp-controls button{width:auto;margin:0;padding:4px 8px;font-size:0.85em;background:rgba(255,255,255,.15);color:#fff;border:0;border-radius:4px;cursor:pointer}
#problem-panel .pp-controls button:hover{background:rgba(255,255,255,.28)}
#problem-panel.pp-collapsed .pp-body{display:none}
#problem-panel .pp-body{padding:8px 12px 14px}
#problem-panel details.pp-layer{border-bottom:1px solid var(--rule);padding:8px 0}
#problem-panel details.pp-layer:last-child{border-bottom:0}
#problem-panel details.pp-layer summary{cursor:pointer;font-weight:700;font-size:0.95em;padding:2px 0}
#problem-panel .pp-guide{font-size:0.9em;color:var(--slate);margin:6px 0 8px}
#problem-panel .pp-conditions{list-style:none;margin:0;padding:0}
#problem-panel .pp-conditions li{padding:4px 0}
#problem-panel .pp-conditions label{display:flex;gap:7px;align-items:flex-start;font-size:0.92em;line-height:1.5;cursor:pointer}
#problem-panel .pp-conditions input{margin-top:3px;flex-shrink:0}
#problem-panel .pp-conditions li:has(input:checked) span{color:var(--faint);text-decoration:line-through}
#problem-panel .pp-images{margin-top:8px;display:flex;flex-direction:column;gap:8px}
#problem-panel .pp-img{width:100%;border:1px solid var(--rule-strong);border-radius:4px;cursor:zoom-in}
#problem-panel .pp-img.zoomed{cursor:zoom-out;width:auto;max-width:none}
#problem-panel .pp-empty{padding:20px 14px;color:var(--slate);font-size:0.95em;text-align:center}
#problem-panel .pp-fallback-hint{font-size:0.82em;color:var(--faint);padding:8px 12px 0}