:root {
  --red: #EE3124;
  --red-dark: #C8231A;
  --dark: #1c1c1c;
  --ink: #1a1a1a;
  --muted: #5b5853;
  --line: #dcd8d2;
  --panel: #f3f2ef;
  --stage: #f2f2f2;
  --bg: #ffffff;
  --radius: 6px;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font-family: 'Barlow', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; line-height: 1.5;
}
img { max-width: 100%; }
.wrap { max-width: 1240px; margin: 0 auto; padding: 0 24px; }

/* Header */
.site-head { background: var(--dark); color: #fff; border-bottom: 3px solid var(--red); }
.site-head-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 68px; flex-wrap: wrap; padding-top: 10px; padding-bottom: 10px; }
.logo { height: 28px; width: auto; display: block; }
.head-tag { font-family: 'Barlow Condensed', sans-serif; font-weight: 600; letter-spacing: 2px; text-transform: uppercase; font-size: 14px; color: #d6d3cf; }

/* Layout */
.layout { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); gap: 48px; padding-top: 40px; padding-bottom: 56px; align-items: start; }
.stage-col { position: sticky; top: 24px; }

.stage-card { background: var(--stage); border-radius: var(--radius); overflow: hidden; }
.stage { position: relative; width: 100%; aspect-ratio: 1 / 1; }
.stage img { position: absolute; inset: 0; width: 100%; height: 100%; display: block; transition: opacity .25s ease; }
.stage.is-swapping #layer-pan, .stage.is-swapping #layer-burner { opacity: 0; }
.stage-meta { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; padding: 12px 18px 16px; }
.stage-badge { font-family: 'Barlow Condensed', sans-serif; font-weight: 700; font-size: 18px; letter-spacing: .5px; text-transform: uppercase; }
.stage-note { font-size: 13px; color: var(--muted); }

/* Config column */
.eyebrow { margin: 0 0 6px; font-family: 'Barlow Condensed', sans-serif; font-weight: 600; letter-spacing: 2px; text-transform: uppercase; font-size: 14px; color: var(--red-dark); }
.page-title { margin: 0; font-family: 'Barlow Condensed', sans-serif; font-weight: 700; font-size: 44px; line-height: 1.02; text-transform: uppercase; text-wrap: balance; }
.lede { margin: 10px 0 24px; color: var(--muted); max-width: 52ch; }

.steps { display: flex; flex-direction: column; gap: 22px; }
.step { border: 0; margin: 0; padding: 0; min-width: 0; }
.step legend { padding: 0; margin-bottom: 10px; display: flex; align-items: center; gap: 10px; font-family: 'Barlow Condensed', sans-serif; font-weight: 700; font-size: 20px; letter-spacing: 1.2px; text-transform: uppercase; }
.step-num { display: inline-grid; place-items: center; width: 26px; height: 26px; border-radius: 50%; background: var(--dark); color: #fff; font-size: 15px; letter-spacing: 0; }
.hint { margin: 8px 0 0; font-size: 13.5px; color: var(--muted); }

.choice-grid { display: grid; gap: 10px; }
.choice-grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.choice-grid.four { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.choice-grid.three { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.choice { position: relative; display: block; cursor: pointer; }
.choice input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.choice-body { display: flex; flex-direction: column; justify-content: center; min-height: 52px; padding: 10px 14px; border: 2px solid var(--line); border-radius: var(--radius); background: #fff; transition: border-color .15s, background-color .15s, box-shadow .15s; }
.choice.card .choice-body { min-height: 72px; }
.choice-title { font-weight: 700; font-size: 16px; line-height: 1.2; }
.choice-sub { font-size: 13.5px; color: var(--muted); margin-top: 2px; }
.choice.size .choice-body { align-items: center; text-align: center; }
.choice.size .choice-title { font-family: 'Barlow Condensed', sans-serif; font-size: 24px; }

.choice:hover .choice-body { border-color: #a9a39b; }
.choice input:checked + .choice-body { border-color: var(--red); background: #fff6f5; box-shadow: inset 0 0 0 1px var(--red); }
.choice input:focus-visible + .choice-body { outline: 3px solid #1c1c1c; outline-offset: 2px; }

/* Result */
.result { margin-top: 28px; border-top: 3px solid var(--red); background: var(--panel); padding: 20px 22px 22px; border-radius: 0 0 var(--radius) var(--radius); }
.result-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 16px; flex-wrap: wrap; }
.result-label { font-size: 12.5px; font-weight: 600; letter-spacing: 1.4px; text-transform: uppercase; color: var(--muted); }
.result-sku { font-family: 'Barlow Condensed', sans-serif; font-weight: 700; font-size: 30px; letter-spacing: .5px; line-height: 1.1; overflow-wrap: anywhere; }
.result-btu { text-align: right; }
.result-btu-val { font-family: 'Barlow Condensed', sans-serif; font-weight: 700; font-size: 30px; line-height: 1.1; color: var(--red-dark); }

.result-specs { margin: 16px 0 0; display: grid; grid-template-columns: max-content 1fr; border-top: 1px solid var(--line); }
.result-specs dt, .result-specs dd { margin: 0; padding: 8px 0; border-bottom: 1px solid var(--line); font-size: 14.5px; }
.result-specs dt { font-weight: 600; padding-right: 18px; }

.result-actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 18px; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 48px; padding: 0 20px; border-radius: var(--radius); font-weight: 700; font-size: 16px; text-decoration: none; border: 2px solid transparent; transition: background-color .15s, border-color .15s, color .15s; }
.btn-primary { background: var(--red-dark); color: #fff; }
.btn-primary:hover { background: #a91c14; }
.btn-ghost { border-color: var(--dark); color: var(--dark); background: transparent; }
.btn-ghost:hover { background: var(--dark); color: #fff; }
.btn:focus-visible { outline: 3px solid var(--dark); outline-offset: 2px; }

/* Footer */
.site-foot { border-top: 1px solid var(--line); padding: 18px 0 28px; font-size: 13px; color: var(--muted); }

/* Responsive */
@media (max-width: 960px) {
  .layout { grid-template-columns: 1fr; gap: 28px; padding-top: 24px; }
  .stage-col { position: static; }
  .stage-card { max-width: 560px; margin: 0 auto; width: 100%; }
  .page-title { font-size: 36px; }
}
@media (max-width: 520px) {
  .wrap { padding: 0 16px; }
  .choice-grid.four { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .result-btu { text-align: left; }
  .btn { width: 100%; }
  .head-tag { font-size: 12px; letter-spacing: 1.5px; }
}
@media (prefers-reduced-motion: reduce) { .stage img, .choice-body, .btn { transition: none; } }
.foot-link { display: inline-block; margin-left: 6px; color: var(--red-dark); font-weight: 600; text-decoration: underline; text-underline-offset: 2px; }
.foot-link:hover { color: var(--ink); }
.foot-link:focus-visible { outline: 3px solid var(--dark); outline-offset: 2px; }