.tool-main { max-width: 920px; margin: 0 auto; padding: 48px 24px 72px; }
.tool-heading { max-width: 680px; margin-bottom: 32px; }
.tool-heading h1 { font-size: clamp(32px, 5vw, 48px); line-height: 1.1; letter-spacing: -.02em; margin: 0 0 16px; }
.tool-heading p { color: var(--muted); }
.tool-main fieldset { border: 0; padding: 0; margin: 0 0 24px; min-width: 0; }
.tool-main legend { font-weight: 600; margin-bottom: 14px; }
.choices { display: flex; flex-wrap: wrap; gap: 12px; }
.choices label { display: flex; align-items: center; gap: 10px; background: var(--card); border: 1px solid var(--sec-line); border-radius: 12px; padding: 16px 24px; cursor: pointer; }
.choices input { width: 18px; height: 18px; accent-color: var(--primary); }
.choices label:has(:checked) { border-color: var(--primary); background: var(--info-bg); }
.fields { display: grid; grid-template-columns: 1fr 1fr; gap: 18px 24px; }
.fields label { display: flex; flex-direction: column; gap: 6px; font-size: 16px; font-weight: 600; }
.fields input { font: 400 18px/1.4 var(--font); width: 100%; min-width: 0; border: 1px solid var(--sec-line); border-radius: 8px; padding: 11px 12px; background: var(--page); color: var(--ink); }
.fields label:last-child { grid-column: 1 / -1; }
#invoice-fields { padding: 24px; background: var(--card); border-radius: 20px; }
#unsupported { background: var(--card); padding: 24px; border-radius: 20px; margin-bottom: 32px; }
.tool-main h2 { font-size: 24px; line-height: 1.25; margin: 0 0 12px; }
.tool-main h3 { font-size: 18px; margin: 24px 0 8px; }
#draft-result { border: 1px solid var(--sec-line); border-radius: 20px; padding: 24px; margin: 24px 0; }
.result-head { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.tool-notice { font-weight: 600; font-size: 16px; }
#letter-output { display: block; width: 100%; border: 1px solid var(--sec-line); border-radius: 8px; padding: 20px; resize: vertical; font: 400 16px/1.6 var(--font); color: var(--ink); background: var(--paper); }
.result-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 20px; }
.tool-explainer { max-width: 680px; border-top: 1px solid var(--line); margin-top: 40px; padding-top: 32px; }
.tool-explainer section { margin-bottom: 32px; }
.tool-explainer p { color: var(--muted); margin: 0; }
.tool-main [hidden] { display: none !important; }
.tool-main :focus-visible { outline: var(--focus-ring); outline-offset: var(--focus-offset); }
.tool-main .sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
@media (max-width: 600px) {
  .tool-main { padding: 32px 16px 48px; }
  .fields { grid-template-columns: 1fr; }
  .choices { flex-direction: column; }
  #invoice-fields, #draft-result, #unsupported { padding: 18px; }
  .top .wrap > a:not(.brand) { font-size: 14px; max-width: 125px; text-align: right; }
}