:root {
  --bg: #f5f6f8;
  --card: #ffffff;
  --ink: #1f2933;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-dark: #1d4ed8;
  --border: #d8dce3;
  --ok: #047857;
  --err: #b91c1c;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.5;
  padding: 2rem 1rem;
}

main {
  max-width: 640px;
  margin: 0 auto;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 2rem;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.05);
}

h1 { margin: 0 0 .25rem; font-size: 1.5rem; }
.lead { margin: 0 0 1.5rem; color: var(--muted); }

form { display: flex; flex-direction: column; gap: 1.1rem; }
.row { display: flex; gap: 1rem; }
.row .field { flex: 1; }

.field { display: flex; flex-direction: column; gap: .35rem; }
label { font-weight: 600; font-size: .9rem; }
.opt { font-weight: 400; color: var(--muted); }

input {
  font: inherit;
  padding: .6rem .7rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
}
input:focus { outline: 2px solid var(--accent); border-color: var(--accent); }

.hint { margin: 0; font-size: .8rem; color: var(--muted); }

button {
  font: inherit;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: 8px;
  padding: .8rem 1rem;
  cursor: pointer;
  transition: background .15s;
}
button:hover:not(:disabled) { background: var(--accent-dark); }
button:disabled { opacity: .6; cursor: progress; }

.status {
  margin-top: 1.25rem;
  padding: .75rem 1rem;
  border-radius: 8px;
  font-size: .9rem;
  white-space: pre-line;
}
.status.ok  { background: #ecfdf5; color: var(--ok);  border: 1px solid #a7f3d0; }
.status.err { background: #fef2f2; color: var(--err); border: 1px solid #fecaca; }
.status.info{ background: #eff6ff; color: var(--accent-dark); border: 1px solid #bfdbfe; }

.preview { margin-top: 1.25rem; }
.preview table { border-collapse: collapse; width: 100%; font-size: .85rem; }
.preview th, .preview td { border: 1px solid var(--border); padding: .35rem .5rem; text-align: left; }
.preview th { background: #f3f4f6; }
.preview td.num { text-align: right; font-variant-numeric: tabular-nums; }