:root {
  --bg: #f4f6f8;
  --panel: #ffffff;
  --ink: #1f2d3d;
  --muted: #7a8699;
  --primary: #2b7de9;
  --primary-d: #1f6fd0;
  --line: #e3e8ef;
  --used: #c7ced8;
  --accent: #fff4d6;
  --neg: #e8743b;
  --pos: #2bb673;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.55;
}
#app { max-width: 1180px; margin: 0 auto; padding: 24px 16px 60px; }
.hidden { display: none !important; }

.panel {
  background: var(--panel);
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(20,40,70,.07);
  padding: 28px 32px;
  max-width: 720px;
  margin: 0 auto;
}
.panel.wide { max-width: 1100px; }
.panel.center { text-align: center; }

h1 { font-size: 24px; margin: 0 0 8px; }
h2 { font-size: 20px; margin: 0 0 12px; }
h3 { font-size: 15px; margin: 18px 0 6px; color: var(--ink); }
.lead { color: var(--muted); margin-top: 0; }
.muted { color: var(--muted); font-size: 13px; }
.err { color: #c0392b; font-size: 13px; min-height: 16px; margin: 6px 0; }

.intro { background: #f8fafc; border: 1px solid var(--line); border-radius: 10px; padding: 4px 18px 12px; margin: 16px 0; }
.intro p { font-size: 14px; margin: 6px 0; }
.intro ul { margin: 6px 0; padding-left: 20px; font-size: 14px; }
.dist { display: inline-block; font-family: ui-monospace, Menlo, Consolas, monospace; background: #eef3fa; border-radius: 6px; padding: 4px 8px; font-size: 13px; }

.field { display: block; margin: 18px 0 4px; }
.field span { display: block; font-size: 14px; margin-bottom: 6px; font-weight: 600; }
.field input {
  width: 100%; padding: 11px 12px; font-size: 15px;
  border: 1px solid var(--line); border-radius: 8px; outline: none;
}
.field input:focus { border-color: var(--primary); }

.btn {
  display: inline-block; border: 0; border-radius: 8px; padding: 11px 20px;
  font-size: 15px; cursor: pointer; background: #eef2f7; color: var(--ink);
  text-decoration: none; transition: .15s;
}
.btn:hover { filter: brightness(.97); }
.btn.primary { background: var(--primary); color: #fff; }
.btn.primary:hover { background: var(--primary-d); }
.btn.primary:disabled { background: #b9c6d6; cursor: not-allowed; }
.btn.ghost { background: #eef2f7; }

.actions { display: flex; gap: 12px; justify-content: flex-end; margin-top: 22px; }

/* Step 2 list */
.stmt-list { max-height: 52vh; overflow: auto; border: 1px solid var(--line); border-radius: 10px; padding: 6px; }
.stmt-item { display: flex; gap: 10px; padding: 10px 12px; border-bottom: 1px solid #f0f3f7; font-size: 14px; }
.stmt-item:last-child { border-bottom: 0; }
.stmt-item .sid { flex: 0 0 38px; font-weight: 700; color: var(--primary); }

/* Step 3 layout */
.sort-head { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 8px; }
.progress { font-size: 14px; color: var(--muted); }
.progress b { color: var(--primary); font-size: 18px; }
.hint { font-size: 13px; color: var(--muted); background: #f8fafc; border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; margin: 12px 0 16px; }

.sort-layout { display: flex; gap: 20px; align-items: flex-start; flex-wrap: wrap; }
.pool-wrap { flex: 1 1 320px; min-width: 280px; }
.pool-title, .grid-banner { font-size: 13px; font-weight: 600; color: var(--muted); margin-bottom: 8px; }
.pool { max-height: 62vh; overflow: auto; padding-right: 4px; }
.pool-grid { display: grid; grid-template-columns: 58px 1fr; gap: 6px; align-items: stretch; }
.pool-h { font-size: 12px; font-weight: 700; color: var(--muted); padding: 4px 8px; position: sticky; top: 0; background: var(--panel); z-index: 1; }
.pool-row { display: contents; }
.pool-num, .pool-txt {
  border: 1px solid var(--line); border-radius: 8px; background: #fff;
  padding: 9px 10px; font-size: 13px; user-select: none; min-width: 0;
}
.pool-num { font-weight: 700; color: var(--primary); text-align: center; cursor: grab; }
.pool-txt { cursor: grab; line-height: 1.45; }
.pool-row.carry .pool-num, .pool-row.carry .pool-txt { outline: 2px solid var(--primary); background: var(--accent); }
.pool-row.used .pool-num, .pool-row.used .pool-txt { background: #f1f3f6; color: var(--used); border-style: dashed; cursor: not-allowed; }
.pool-row.used .pool-num { color: var(--used); }
.pool-row.dragging .pool-num, .pool-row.dragging .pool-txt { opacity: .4; }

.card {
  display: flex; gap: 8px; align-items: flex-start;
  background: #fff; border: 1px solid var(--line); border-radius: 8px;
  padding: 9px 11px; font-size: 13px; cursor: grab; user-select: none;
  box-shadow: 0 1px 2px rgba(0,0,0,.04);
}
.card .sid { flex: 0 0 34px; font-weight: 700; color: var(--primary); }
.card .txt { flex: 1; }
.card.sx-only { justify-content: center; padding: 8px 6px; }
.card.sx-only .sid { flex: none; font-size: 15px; }
.card.used { background: #f1f3f6; color: var(--used); border-style: dashed; cursor: not-allowed; }
.card.used .sid { color: var(--used); }
.card.carry { outline: 2px solid var(--primary); background: var(--accent); }
.card.dragging { opacity: .4; }

.grid-wrap { flex: 2 1 560px; min-width: 320px; }
.grid-banner { display: flex; justify-content: space-between; }

.qgrid { display: flex; gap: 6px; align-items: flex-start; background: #f8fafc; border: 1px solid var(--line); border-radius: 10px; padding: 14px 10px; overflow-x: auto; }
.column { display: flex; flex-direction: column; gap: 6px; align-items: stretch; min-width: 56px; }
.col-head { text-align: center; font-weight: 700; font-size: 15px; padding: 4px 0; border-radius: 6px; }
.col-head.neg { color: var(--neg); }
.col-head.pos { color: var(--pos); }
.col-cap { text-align: center; font-size: 11px; color: var(--muted); margin-bottom: 2px; }
.slot {
  min-height: 46px; border: 1.5px dashed #cdd6e2; border-radius: 8px;
  background: #fff; display: flex; align-items: center; justify-content: center;
  font-size: 12px; padding: 4px; transition: .12s;
}
.slot.over { border-color: var(--primary); background: #eaf3ff; }
.slot.filled { border-style: solid; border-color: #bcd2ee; cursor: pointer; }
.slot .card { width: 100%; cursor: grab; }

/* Preview grid read-only */
#previewGrid .slot { cursor: default; border-style: solid; }
#previewGrid .card { cursor: default; }
#previewGrid .slot .sid { color: var(--primary); }

.check { font-size: 46px; color: var(--pos); margin-bottom: 8px; }

@media (max-width: 720px) {
  .sort-layout { flex-direction: column; }
  .pool, #qgrid { max-height: none; }
}