:root {
  --brand: #1f4fd8;
  --brand-2: #e8eefc;
  --ink: #1b1f2a;
  --muted: #667085;
  --line: #e4e7ec;
  --bg: #f6f7fb;
  --card: #ffffff;
  --ok: #12805c;
  --ok-bg: #e7f6ef;
  --warn: #b54708;
  --warn-bg: #fff4e5;
  --bad: #c01048;
  --radius: 14px;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  font-family: "Pretendard", "Apple SD Gothic Neo", "Malgun Gothic", system-ui, sans-serif;
  background: var(--bg); color: var(--ink); line-height: 1.6; font-size: 16px;
  -webkit-text-size-adjust: 100%;
}
.wrap { max-width: 720px; margin: 0 auto; padding: 0 16px 96px; }
.wrap.wide { max-width: 1180px; }
header.top {
  position: sticky; top: 0; z-index: 5; background: rgba(246, 247, 251, .92); backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
header.top .wrap { display: flex; align-items: center; gap: 12px; padding-top: 10px; padding-bottom: 10px; }
.logo { font-weight: 800; font-size: 20px; color: var(--brand); letter-spacing: -0.5px; }
.logo small { font-weight: 500; color: var(--muted); font-size: 13px; margin-left: 6px; }
.spacer { flex: 1; }
.who { font-size: 13px; color: var(--muted); }

.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; margin: 14px 0; }
h2 { font-size: 18px; margin: 0 0 12px; }
h3 { font-size: 16px; margin: 16px 0 8px; }
label { display: block; font-size: 14px; color: var(--muted); margin: 10px 0 4px; }
input, select, textarea {
  width: 100%; font: inherit; padding: 11px 12px; border: 1px solid var(--line); border-radius: 10px; background: #fff; color: var(--ink);
}
textarea { min-height: 90px; resize: vertical; }
.row { display: flex; gap: 10px; flex-wrap: wrap; }
.row > * { flex: 1 1 140px; }

button, .btn {
  font: inherit; font-weight: 600; border: 0; border-radius: 12px; padding: 12px 16px; cursor: pointer;
  background: var(--brand); color: #fff; display: inline-flex; align-items: center; justify-content: center; gap: 6px; text-decoration: none;
}
button.ghost, .btn.ghost { background: #fff; color: var(--ink); border: 1px solid var(--line); }
button.soft { background: var(--brand-2); color: var(--brand); }
button.ok { background: var(--ok); }
button.bad { background: #fff; color: var(--bad); border: 1px solid #f3c2d1; }
button:disabled { opacity: .5; cursor: default; }
button.small { padding: 7px 11px; font-size: 14px; border-radius: 9px; }

.shoot { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.shoot label.big {
  margin: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px;
  min-height: 132px; border-radius: 18px; cursor: pointer; font-weight: 700; font-size: 17px;
}
.shoot label.big.primary { background: var(--brand); color: #fff; }
.shoot label.big.secondary { background: #fff; color: var(--ink); border: 1px solid var(--line); }
.shoot label.big span.ico { font-size: 34px; line-height: 1; }
.shoot input { display: none; }
.hint { font-size: 13px; color: var(--muted); }

.tabs { display: flex; gap: 6px; margin: 14px 0 4px; overflow-x: auto; }
.tabs button { background: #fff; color: var(--muted); border: 1px solid var(--line); white-space: nowrap; }
.tabs button.on { background: var(--ink); color: #fff; border-color: var(--ink); }

.photo { width: 100%; border-radius: 12px; border: 1px solid var(--line); display: block; background: #fff; }
.thumb { width: 88px; height: 88px; object-fit: cover; border-radius: 10px; border: 1px solid var(--line); flex: none; }

.notice { border-radius: 12px; padding: 12px 14px; font-size: 15px; }
.notice.info { background: var(--brand-2); color: #1d3a8a; }
.notice.warn { background: var(--warn-bg); color: var(--warn); }
.notice.ok { background: var(--ok-bg); color: var(--ok); }
.notice.bad { background: #fdecf1; color: var(--bad); }

.spin { width: 22px; height: 22px; border: 3px solid var(--brand-2); border-top-color: var(--brand); border-radius: 50%; animation: sp 0.9s linear infinite; display: inline-block; vertical-align: middle; }
@keyframes sp { to { transform: rotate(360deg); } }

/* 풀이 */
.sol-unit { font-size: 13px; color: var(--brand); font-weight: 700; }
.sol-problem { margin: 8px 0; font-size: 14px; color: var(--muted); }
.sol-problem summary { cursor: pointer; }
.sol-problem > div { background: var(--bg); border-radius: 10px; padding: 10px 12px; margin-top: 6px; color: var(--ink); }
.sol-concept { background: var(--brand-2); border-radius: 12px; padding: 12px 14px; margin: 10px 0; }
.sol-concept b { color: var(--brand); font-size: 14px; }
.sol-steps { list-style: none; counter-reset: st; padding: 0; margin: 12px 0; }
.sol-steps li { counter-increment: st; position: relative; padding: 2px 0 14px 40px; border-left: 2px solid var(--line); margin-left: 13px; }
.sol-steps li:last-child { border-left-color: transparent; }
.sol-steps li::before {
  content: counter(st); position: absolute; left: -14px; top: 0; width: 26px; height: 26px; border-radius: 50%;
  background: var(--brand); color: #fff; font-weight: 700; font-size: 14px; display: grid; place-items: center;
}
.step-title { font-weight: 700; }
.step-body { overflow-x: auto; }
.sol-answer { background: var(--ink); color: #fff; border-radius: 12px; padding: 12px 14px; font-size: 18px; font-weight: 700; }
.sol-answer > span:first-child { font-size: 13px; opacity: .7; margin-right: 8px; }
.sol-answer > span:not(:first-child) { font-size: inherit; opacity: 1; }
.sol-warn, .sol-check { margin-top: 10px; font-size: 15px; padding: 10px 12px; border-radius: 10px; }
.sol-warn { background: var(--warn-bg); }
.sol-warn b { color: var(--warn); margin-right: 6px; }
.sol-check { background: var(--ok-bg); }
.sol-check b { color: var(--ok); margin-right: 6px; }
.katex-display { overflow-x: auto; overflow-y: hidden; padding: 4px 0; }

.fb { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 14px; }
.followup { border-top: 1px dashed var(--line); margin-top: 14px; padding-top: 12px; }
.followup .q { font-weight: 700; color: var(--brand); }

.list-item { display: flex; gap: 12px; align-items: center; padding: 10px 0; border-bottom: 1px solid var(--line); cursor: pointer; }
.list-item:last-child { border-bottom: 0; }
.list-item .meta { flex: 1; min-width: 0; }
.list-item .meta .t { font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.pill { display: inline-block; font-size: 12px; padding: 2px 8px; border-radius: 99px; background: var(--bg); color: var(--muted); font-weight: 600; }
.pill.ok { background: var(--ok-bg); color: var(--ok); }
.pill.warn { background: var(--warn-bg); color: var(--warn); }
.pill.bad { background: #fdecf1; color: var(--bad); }
.pill.brand { background: var(--brand-2); color: var(--brand); }

table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { text-align: left; padding: 8px 6px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { color: var(--muted); font-weight: 600; background: #fafbfc; }
.num { text-align: right; font-variant-numeric: tabular-nums; }
.table-scroll { overflow-x: auto; }

.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 800px) { .grid2 { grid-template-columns: 1fr; } }
.kpis { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; }
.kpi { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; }
.kpi .v { font-size: 24px; font-weight: 800; }
.kpi .l { font-size: 13px; color: var(--muted); }
.hidden { display: none !important; }

/* 오답노트 인쇄 */
@media print {
  header.top, .tabs, .no-print, button { display: none !important; }
  body { background: #fff; }
  .wrap { max-width: none; padding: 0; }
  .card { border: 0; padding: 0; margin: 0 0 12mm; break-inside: avoid; }
  .print-page { break-after: page; }
}
.dasibom-cover { text-align: center; padding: 60px 16px; border: 2px solid var(--ink); border-radius: 18px; background: #fff; }
.dasibom-cover .b1 { font-size: 15px; letter-spacing: 6px; color: var(--muted); }
.dasibom-cover .b2 { font-size: 40px; font-weight: 900; letter-spacing: -1px; margin: 6px 0; }
.dasibom-cover .b3 { font-size: 20px; color: var(--brand); font-weight: 700; }
.redo-box { border: 1.5px dashed var(--line); border-radius: 12px; min-height: 160px; margin-top: 10px; padding: 8px 12px; color: var(--muted); font-size: 13px; }
.pill:empty { display: none; }