:root {
  --ink: #1b2430;
  --muted: #5b6672;
  --line: #d8dee6;
  --brand: #123f6b;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  display: flex;
  align-items: flex-start;
  min-height: 100vh;
  color: var(--ink);
  background: #eef1f5;
}

/* ---- control panel ---- */

.panel {
  flex: none;
  width: 340px;
  padding: 24px 22px 40px;
  background: #fff;
  border-right: 1px solid var(--line);
  position: sticky;
  top: 0;
  max-height: 100vh;
  overflow-y: auto;
}

.panel h1 { font-size: 18px; margin: 0 0 20px; color: var(--brand); }

.field { display: block; margin-bottom: 20px; }

.label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 6px; }
.label small { display: block; font-weight: 400; color: var(--muted); margin-top: 2px; }

textarea {
  width: 100%;
  font: 13px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  resize: vertical;
}

textarea:focus, input:focus { outline: 2px solid var(--brand); outline-offset: 1px; }

input[type=file] { font-size: 13px; width: 100%; }

.hint, .warn { font-size: 12px; color: var(--muted); line-height: 1.45; margin: 6px 0 0; }
.warn { margin-top: 12px; }
code { font-size: 11.5px; background: #f1f4f8; padding: 1px 4px; border-radius: 3px; }

.radios { display: flex; flex-direction: column; gap: 6px; font-size: 13px; }
.check { display: block; font-size: 13px; margin-bottom: 6px; }

.count { font-size: 13px; font-weight: 600; margin: 0 0 10px; }

.print-btn {
  width: 100%;
  padding: 11px;
  font-size: 14px;
  font-weight: 600;
  color: #fff;
  background: var(--brand);
  border: 0;
  border-radius: 6px;
  cursor: pointer;
}
.print-btn:hover { background: #0d2e4e; }

/* ---- on-screen preview of the sheets ---- */

.preview {
  flex: 1;
  padding: 28px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
}

@media screen {
  .sheet {
    box-shadow: 0 2px 14px rgba(20, 35, 60, 0.18);
    flex: none;
  }
}

.empty-state { color: var(--muted); font-size: 14px; margin-top: 60px; }

select {
  width: 100%;
  font-size: 13px;
  padding: 7px 8px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
}

.custom-size {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px 10px;
  margin-top: 10px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #f8fafc;
  font-size: 12px;
}
.custom-size label { display: flex; align-items: center; gap: 5px; }
.custom-size input { width: 100%; min-width: 0; padding: 4px 6px; border: 1px solid var(--line); border-radius: 4px; }
.custom-size .hint { grid-column: 1 / -1; margin: 0; }

.topmargin { display: flex; align-items: center; gap: 6px; font-size: 13px; margin-top: 10px; }
.topmargin input { width: 70px; padding: 4px 6px; border: 1px solid var(--line); border-radius: 4px; }