:root{
  --ink:#172033; --muted:#5d6678; --paper:#f5f8fc; --panel:#fff; --line:#c5d2e2;
  --grid:#dce6f3; --blue:#2457c5; --green:#16745f; --red:#c7374f; --amber:#c07a18;
  --shadow:0 14px 40px rgba(23,32,51,.10);
}
*{box-sizing:border-box}
body{margin:0;color:var(--ink);background:var(--paper);
  font-family:"Noto Sans KR","Pretendard",system-ui,sans-serif;line-height:1.6;word-break:keep-all}
.wrap{max-width:980px;margin:0 auto;padding:24px 18px 80px}
header.top{display:flex;align-items:center;gap:12px;padding:18px 0;border-bottom:2px solid var(--ink);margin-bottom:22px}
header.top h1{font-size:22px;margin:0}
header.top .sub{color:var(--muted);font-size:13px}
.badge{background:var(--blue);color:#fff;font-weight:800;font-size:12px;padding:5px 10px;border-radius:6px}
.card{background:var(--panel);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);padding:20px;margin-bottom:18px}
.card h2{font-size:18px;margin:0 0 10px;border-left:5px solid var(--blue);padding-left:10px}
.muted{color:var(--muted)}
.row{display:flex;gap:12px;flex-wrap:wrap;align-items:center}
label{font-weight:700;font-size:14px}
input[type=text],input[type=number],input[type=password],input[type=file],textarea,select{
  font:inherit;border:1px solid var(--line);border-radius:8px;padding:9px 11px;background:#fff;color:var(--ink)}
input[type=number]{width:90px}
input[type=file]{width:100%;padding:6px;cursor:pointer}
input[type=file]::file-selector-button{
  margin-right:10px;padding:8px 12px;border:0;border-radius:7px;
  background:var(--blue);color:#fff;font:inherit;font-weight:800;cursor:pointer}
input[type=file]::file-selector-button:hover{filter:brightness(.9)}
textarea{width:100%;min-height:74px;resize:vertical}
.btn{font:inherit;font-weight:800;border:0;border-radius:9px;padding:11px 16px;cursor:pointer;background:var(--ink);color:#fff}
.btn.primary{background:var(--blue)}
.btn.green{background:var(--green)}
.btn.ghost{background:#eaf1fb;color:var(--blue)}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn.small{padding:8px 12px;font-size:13px}
.hidden{display:none}
.concept{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.concept .box{background:#f3f7ff;border:1px solid var(--line);border-radius:8px;padding:12px}
.concept code{background:#0f172a;color:#dbeafe;padding:2px 6px;border-radius:4px;font-family:"JetBrains Mono","Noto Sans KR",monospace}
.studio{display:grid;grid-template-columns:auto 1fr;gap:18px;align-items:start}
canvas{background:#fff;border:1px solid var(--line);border-radius:8px;display:block}
.tools{display:grid;gap:8px}
.tools .grp{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.tag{display:inline-block;background:#eef4ff;color:var(--blue);border-radius:999px;padding:3px 10px;font-size:12px;font-weight:800;margin:2px}
.q{border-top:1px dashed var(--grid);padding:14px 0}
.q:first-child{border-top:0}
.q .qh{font-weight:800;margin-bottom:6px}
.q .qh .pt{color:var(--blue);font-weight:800;margin-left:6px;font-size:13px}
.choices label{display:block;font-weight:500;padding:5px 0;cursor:pointer}
.coord-in{display:inline-flex;gap:6px;align-items:center}
.guard-dot{margin-left:auto;font-size:12px;color:var(--muted);display:flex;align-items:center;gap:6px}
.guard-dot b{display:inline-block;width:9px;height:9px;border-radius:50%;background:var(--green)}
.notice{background:#fff7ed;border:1px solid #f6cf9c;color:#8a4b09;border-radius:8px;padding:10px 12px;font-size:13px;margin-top:10px}
table.grade{width:100%;border-collapse:collapse;background:#fff;margin-top:12px;font-size:13px}
table.grade th,table.grade td{border:1px solid var(--line);padding:7px 9px;text-align:center;vertical-align:middle}
table.grade th{background:#eaf1fb;color:#15346f}
table.grade td.l{text-align:left}
.flag{color:var(--red);font-weight:800}
.ok{color:var(--green);font-weight:800}
@media(max-width:760px){.concept,.studio{grid-template-columns:1fr}canvas{width:100%;height:auto}}