:root {
  --brand: #1d4ed8; --brand-soft: #e8efff;
  --ink: #0f172a; --muted: #64748b; --line: #e2e8f0; --bg: #f5f7fb; --card: #fff;
  --ok: #059669; --ok-soft: #e7f8f1; --bad: #dc2626; --bad-soft: #fdecec; --warn: #c2410c; --warn-soft: #fff3e8;
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 15px/1.5 Inter, Prompt, system-ui, sans-serif; }
h2 { font-size: 18px; margin: 0; display: flex; align-items: center; gap: 10px; }
h3 { font-size: 15px; margin: 20px 0 8px; }
small, .small { font-size: 12px; font-weight: 400; }
.muted { color: var(--muted); }
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 16px; }

.topbar { background: #fff; border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 5; }
.topbar-in { display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 12px; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand b { display: block; font-size: 17px; }
.brand small { color: var(--muted); }
.pill { font-size: 12px; padding: 4px 10px; border-radius: 999px; background: #f1f5f9; color: var(--muted); white-space: nowrap; }
.pill.ok { background: var(--ok-soft); color: var(--ok); }
.pill.warn { background: var(--warn-soft); color: var(--warn); }

main { padding-top: 20px; padding-bottom: 40px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 20px; margin-bottom: 18px; }
.card > h2 { margin-bottom: 14px; }
.card-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 14px; }
.step { width: 26px; height: 26px; border-radius: 50%; background: var(--brand); color: #fff; font-size: 14px; display: inline-grid; place-items: center; }
.row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.row.between { justify-content: space-between; }
.gap-lg { gap: 16px; align-items: flex-end; }

.field { display: flex; flex-direction: column; gap: 4px; font-size: 13px; color: var(--muted); }
.field.wide { max-width: 640px; }
input { font: inherit; color: var(--ink); border: 1px solid var(--line); border-radius: 8px; padding: 7px 10px; background: #fff; min-width: 0; }
input:focus { outline: 2px solid var(--brand-soft); border-color: var(--brand); }
#quick { font-family: ui-monospace, Menlo, monospace; letter-spacing: 1px; }

.btn { font: inherit; font-size: 14px; border: 1px solid transparent; border-radius: 8px; padding: 7px 14px; cursor: pointer; white-space: nowrap; }
.btn:disabled { opacity: .45; cursor: default; }
.btn-primary { background: var(--brand); color: #fff; }
.btn-light { background: #fff; border-color: var(--line); color: var(--ink); }
.btn-light:hover:not(:disabled) { background: #f8fafc; }
.btn-sm { padding: 3px 10px; font-size: 13px; }

/* ชุดข้อสอบ */
.sets { display: flex; align-items: flex-end; gap: 14px; flex-wrap: wrap; margin-bottom: 14px; padding-bottom: 14px; border-bottom: 1px solid var(--line); }
select { font: inherit; color: var(--ink); border: 1px solid var(--line); border-radius: 8px; padding: 7px 10px; background: #fff; }
.tabs { display: flex; gap: 6px; }
.tab { font: inherit; font-size: 14px; border: 1px solid var(--line); background: #fff; border-radius: 99px; padding: 6px 16px; cursor: pointer; color: var(--muted); }
.tab.on { background: var(--brand); border-color: var(--brand); color: #fff; font-weight: 600; }
.tab small { opacity: .8; margin-left: 4px; }
.row3 { display: grid; grid-template-columns: 1fr 1fr 90px; gap: 8px; }
.row3 input, .row3 select { width: 100%; }

/* ตารางเฉลย Part 1: 4 คอลัมน์ x 15 ข้อ เหมือนกระดาษ */
.keygrid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 4px 18px; margin-top: 10px; }
.krow { display: flex; align-items: center; gap: 4px; }
.krow .q { width: 24px; text-align: right; font-size: 12px; color: var(--muted); margin-right: 4px; }
.opt { width: 28px; height: 28px; border-radius: 50%; border: 1px solid #cbd5e1; background: #fff; font-size: 12px; cursor: pointer; padding: 0; color: var(--muted); }
.opt.on { background: var(--brand); border-color: var(--brand); color: #fff; font-weight: 600; }
.key2 { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; }
.key2 label { display: flex; align-items: center; gap: 6px; font-size: 13px; color: var(--muted); }
.key2 input { width: 100%; }

.drop { display: flex; flex-direction: column; align-items: center; gap: 4px; padding: 34px 16px; border: 2px dashed #c7d2fe; border-radius: 12px; background: #f8faff; cursor: pointer; text-align: center; }
.drop.over { background: var(--brand-soft); border-color: var(--brand); }
.progress { margin-top: 14px; display: flex; align-items: center; gap: 12px; }
.bar { flex: 1; height: 8px; border-radius: 99px; background: #eef2f7; overflow: hidden; }
.bar > div { height: 100%; width: 0; background: var(--brand); transition: width .2s; }

.stats { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 12px; }
.stat { background: #f8fafc; border: 1px solid var(--line); border-radius: 10px; padding: 8px 14px; min-width: 110px; }
.stat b { display: block; font-size: 20px; }
.stat span { font-size: 12px; color: var(--muted); }
.table-wrap { overflow-x: auto; }
.tbl { width: 100%; border-collapse: collapse; font-size: 14px; }
.tbl th { text-align: left; font-size: 12px; color: var(--muted); font-weight: 500; padding: 8px; border-bottom: 1px solid var(--line); white-space: nowrap; }
.tbl td { padding: 8px; border-bottom: 1px solid #f1f5f9; vertical-align: middle; }
.tbl .num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.tbl .file { max-width: 220px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.tbl .mono { font-family: ui-monospace, Menlo, monospace; }
.tbl .empty { text-align: center; color: var(--muted); padding: 28px; }
.badge { font-size: 12px; padding: 2px 8px; border-radius: 99px; white-space: nowrap; }
.b-ok { background: var(--ok-soft); color: var(--ok); }
.b-bad { background: var(--bad-soft); color: var(--bad); }
.b-warn { background: var(--warn-soft); color: var(--warn); }
.b-wait { background: #f1f5f9; color: var(--muted); }
.foot { text-align: center; font-size: 12px; }

/* หน้าต่างดูผลรายแผ่น */
dialog { border: 0; padding: 0; border-radius: 14px; width: min(1200px, 96vw); height: 92vh; max-height: 92vh; }
dialog::backdrop { background: rgba(15, 23, 42, .55); }
.viewer { display: grid; grid-template-columns: minmax(0, 1fr) 400px; height: 100%; }
.viewer-img { background: #1e293b; overflow: auto; padding: 12px; }
.viewer-img canvas { width: 100%; height: auto; display: block; background: #fff; border-radius: 6px; }
.viewer-side { overflow-y: auto; overflow-x: hidden; padding: 16px; display: flex; flex-direction: column; gap: 10px; }
.viewer-side h3 { margin: 6px 0 0; }
.scores { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.scores div { background: #f8fafc; border: 1px solid var(--line); border-radius: 10px; padding: 8px; }
.scores b { font-size: 20px; display: block; }
.scores span { font-size: 12px; color: var(--muted); }
.review { background: var(--warn-soft); color: var(--warn); border-radius: 10px; padding: 8px 12px; font-size: 13px; }
.review ul { margin: 4px 0 0; padding-left: 18px; }
.vgrid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 4px; }
.vgrid label, .vgrid2 label { display: flex; align-items: center; gap: 4px; font-size: 12px; border: 1px solid var(--line); border-radius: 6px; padding: 2px 4px; }
.vgrid label span, .vgrid2 label span { width: 20px; text-align: right; color: var(--muted); }
.vgrid select { flex: 1; border: 0; background: transparent; font: inherit; min-width: 0; }
.vgrid2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 4px; }
.vgrid2 input { flex: 1; border: 0; padding: 3px; width: 100%; }
.c-ok { background: var(--ok-soft); border-color: #a7e3cb !important; }
.c-bad { background: var(--bad-soft); border-color: #f5b5b5 !important; }
.c-warn { background: var(--warn-soft); border-color: #f8c9a0 !important; }
.vgrid label i, .vgrid2 label i { font-style: normal; font-size: 11px; color: var(--ok); white-space: nowrap; }

@media (max-width: 900px) {
  .keygrid { grid-template-columns: repeat(2, 1fr); }
  .key2 { grid-template-columns: repeat(2, 1fr); }
  .viewer { grid-template-columns: 1fr; }
  .viewer-img { max-height: 50vh; }
}
@media (max-width: 600px) {
  .keygrid { grid-template-columns: 1fr; }
  .brand small { display: none; }
  .card { padding: 14px; }
}