/* ===== BUILDPLAN — Home Improvement Utility Engine =====
   Design language: workshop / blueprint. Warm clay + charcoal + chalk grid.
   Distinct from CarCost's tile-on-cream look: sidebar tool rail instead of top tiles,
   monospace numerics, dashed measurement lines, stamped section labels. */

:root {
  --clay: #c1502e;
  --clay-dark: #9c3d21;
  --clay-light: #f4e4dc;
  --ink: #1f2420;
  --ink-soft: #4a534c;
  --paper: #faf7f2;
  --paper-dim: #f0ece3;
  --line: #dcd5c8;
  --chalk: #ffffff;
  --green: #4f7a5c;
  --amber: #b8862f;
  --mono: 'SF Mono', 'Consolas', 'Menlo', ui-monospace, monospace;
  --sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --radius: 3px;
  --shadow: 0 1px 2px rgba(31,36,32,.06), 0 4px 14px rgba(31,36,32,.05);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--sans);
  color: var(--ink);
  background: var(--paper);
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 28px 28px;
  background-attachment: fixed;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
a { color: var(--clay-dark); }
h1, h2, h3, h4 { font-family: var(--sans); font-weight: 800; letter-spacing: -0.01em; color: var(--ink); margin: 0 0 .5em; }
p { margin: 0 0 1em; }
.mono { font-family: var(--mono); }

/* ---------- HEADER ---------- */
.site-head {
  position: sticky; top: 0; z-index: 40;
  background: var(--ink); color: var(--paper);
  border-bottom: 3px solid var(--clay);
}
.site-head__row {
  display: flex; align-items: center; justify-content: space-between;
  height: 62px;
}
.logo {
  display: flex; align-items: center; gap: 10px;
  background: none; border: 0; cursor: pointer; padding: 0;
  color: var(--paper); font-family: var(--sans); font-weight: 800; font-size: 19px;
}
.logo__mark {
  width: 30px; height: 30px; display: grid; place-items: center;
  background: var(--clay); border-radius: var(--radius); font-size: 15px;
  transform: rotate(-3deg);
}
.logo__sub { font-weight: 500; font-size: 11px; letter-spacing: .08em; text-transform: uppercase; color: #9aa39c; margin-left: 6px; }
.burger { display: none; background: none; border: 1px solid #444; border-radius: var(--radius); width: 40px; height: 36px; cursor: pointer; flex-direction: column; align-items: center; justify-content: center; gap: 4px; }
.burger span { width: 18px; height: 2px; background: var(--paper); display: block; }

.nav { background: #171a17; border-top: 1px solid #2a2f2a; }
.nav__inner { display: flex; flex-wrap: wrap; gap: 2px; padding: 6px 24px; }
.nav__link {
  background: none; border: 0; color: #b7bfb8; cursor: pointer;
  padding: 8px 12px; font-size: 13px; font-weight: 600; border-radius: var(--radius);
  font-family: var(--sans); white-space: nowrap;
}
.nav__link:hover { background: #23271f; color: var(--chalk); }
.nav__link.is-on { background: var(--clay); color: var(--chalk); }

/* ---------- HOME HERO ---------- */
.home-hero {
  padding: 64px 24px 40px; text-align: left; max-width: 880px;
}
.eyebrow {
  display: inline-block; font-family: var(--mono); font-size: 12px; font-weight: 700;
  letter-spacing: .05em; text-transform: uppercase; color: var(--clay-dark);
  background: var(--clay-light); padding: 5px 10px; border-radius: var(--radius);
  margin-bottom: 16px; border: 1px dashed var(--clay);
}
.home-hero h1 { font-size: clamp(32px, 5vw, 50px); line-height: 1.08; margin-bottom: 18px; }
.home-hero h1 em { font-style: normal; color: var(--clay); }
.home-hero p.lead { font-size: 17px; color: var(--ink-soft); max-width: 640px; }
.badges { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 20px; }
.badge {
  font-family: var(--mono); font-size: 12px; font-weight: 600; color: var(--ink-soft);
  background: var(--chalk); border: 1px solid var(--line); padding: 6px 11px; border-radius: var(--radius);
}
.badge::before { content: '✓ '; color: var(--green); }

/* ---------- SECTIONS ---------- */
.section { padding: 36px 24px; }
.group-label {
  font-family: var(--mono); font-size: 12px; font-weight: 700; letter-spacing: .08em;
  text-transform: uppercase; color: var(--ink-soft); margin: 0 0 14px;
  display: flex; align-items: center; gap: 10px;
}
.group-label::after { content: ''; flex: 1; height: 1px; background: var(--line); }

/* ---------- TOOL GRID (home page) ---------- */
.tool-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px; margin-bottom: 36px;
}
.tool-card {
  background: var(--chalk); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px; text-align: left; cursor: pointer; display: flex; gap: 14px; align-items: flex-start;
  box-shadow: var(--shadow); transition: transform .12s ease, border-color .12s ease;
  font-family: var(--sans);
}
.tool-card:hover { border-color: var(--clay); transform: translateY(-2px); }
.tool-card__icon {
  width: 42px; height: 42px; flex-shrink: 0; display: grid; place-items: center;
  background: var(--clay-light); border-radius: var(--radius); font-size: 20px;
}
.tool-card__title { font-weight: 800; font-size: 15px; margin-bottom: 3px; color: var(--ink); }
.tool-card__desc { font-size: 13px; color: var(--ink-soft); line-height: 1.45; }

/* ---------- CALCULATOR LAYOUT ---------- */
.calc-head { padding: 30px 24px 8px; }
.calc-head .eyebrow { margin-bottom: 10px; }
.calc-head h1 { font-size: clamp(26px, 4vw, 36px); }
.calc-head p.lead { color: var(--ink-soft); font-size: 15.5px; max-width: 680px; }

.unit-switch {
  display: inline-flex; background: var(--chalk); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 3px; margin: 16px 0 4px; font-family: var(--mono); font-size: 12.5px; font-weight: 700;
}
.unit-switch button {
  border: 0; background: none; padding: 7px 16px; border-radius: 2px; cursor: pointer;
  color: var(--ink-soft); letter-spacing: .03em;
}
.unit-switch button.is-on { background: var(--ink); color: var(--chalk); }

.calc-grid {
  display: grid; grid-template-columns: minmax(320px, 420px) 1fr; gap: 22px;
  padding: 16px 24px 56px; align-items: start;
}
@media (max-width: 860px) { .calc-grid { grid-template-columns: 1fr; } }

.panel {
  background: var(--chalk); border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); overflow: hidden;
}
.panel__head {
  padding: 14px 18px; border-bottom: 1px dashed var(--line); background: var(--paper-dim);
  font-family: var(--mono); font-size: 12px; font-weight: 700; text-transform: uppercase;
  letter-spacing: .06em; color: var(--ink-soft); display: flex; align-items: center; justify-content: space-between;
}
.panel__body { padding: 18px; }

.field { margin-bottom: 16px; }
.field:last-child { margin-bottom: 0; }
.field label {
  display: block; font-size: 12.5px; font-weight: 700; color: var(--ink); margin-bottom: 6px;
}
.field .hint { font-size: 11.5px; color: var(--ink-soft); margin-top: 4px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.input-wrap { position: relative; display: flex; align-items: stretch; }
.input-wrap input, .input-wrap select {
  width: 100%; padding: 10px 12px; border: 1px solid var(--line); border-radius: var(--radius);
  font-family: var(--mono); font-size: 14px; background: var(--paper); color: var(--ink);
}
.input-wrap select { font-family: var(--sans); font-weight: 600; cursor: pointer; }
.input-wrap input:focus, .input-wrap select:focus { outline: 2px solid var(--clay); outline-offset: -1px; border-color: var(--clay); }
.input-wrap .unit-tag {
  display: flex; align-items: center; padding: 0 10px; background: var(--paper-dim);
  border: 1px solid var(--line); border-left: 0; border-radius: 0 var(--radius) var(--radius) 0;
  font-family: var(--mono); font-size: 12px; font-weight: 700; color: var(--ink-soft); white-space: nowrap;
}
.input-wrap input { border-radius: var(--radius) 0 0 var(--radius); }
.checkbox-row { display: flex; align-items: center; gap: 8px; }
.checkbox-row input { width: 16px; height: 16px; accent-color: var(--clay); }
.checkbox-row label { margin: 0; font-weight: 600; }

/* ---------- RESULTS ---------- */
.result-headline {
  background: var(--ink); color: var(--paper); border-radius: var(--radius);
  padding: 22px; margin-bottom: 16px; position: relative; overflow: hidden;
}
.result-headline::before {
  content: ''; position: absolute; inset: 0; opacity: .06;
  background-image: repeating-linear-gradient(45deg, #fff 0 1px, transparent 1px 12px);
}
.result-headline__label {
  font-family: var(--mono); font-size: 11.5px; text-transform: uppercase; letter-spacing: .08em;
  color: #b7bfb8; margin-bottom: 6px; position: relative;
}
.result-headline__value {
  font-family: var(--mono); font-size: clamp(30px, 4vw, 42px); font-weight: 800; color: var(--chalk);
  position: relative; line-height: 1.1;
}
.result-headline__value .unit { font-size: .45em; color: var(--clay); font-weight: 700; margin-left: 6px; }
.result-headline__sub { font-size: 13px; color: #9aa39c; margin-top: 8px; position: relative; }

.result-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; margin-bottom: 16px; }
.stat-box {
  background: var(--chalk); border: 1px solid var(--line); border-radius: var(--radius); padding: 13px 14px;
}
.stat-box__v { font-family: var(--mono); font-size: 20px; font-weight: 800; color: var(--ink); }
.stat-box__l { font-size: 11.5px; color: var(--ink-soft); margin-top: 3px; }

.line-items { background: var(--chalk); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; margin-bottom: 16px; }
.line-item {
  display: flex; justify-content: space-between; align-items: center;
  padding: 11px 16px; border-bottom: 1px dashed var(--line); font-size: 13.5px;
}
.line-item:last-child { border-bottom: 0; }
.line-item span:first-child { color: var(--ink-soft); }
.line-item b { font-family: var(--mono); color: var(--ink); }
.line-item.total { background: var(--clay-light); font-weight: 700; }
.line-item.total b { color: var(--clay-dark); font-size: 15px; }

.buy-card {
  border: 2px solid var(--clay); border-radius: var(--radius); padding: 16px 18px;
  background: var(--clay-light); display: flex; align-items: center; justify-content: space-between; gap: 12px;
}
.buy-card__label { font-size: 12.5px; font-weight: 700; color: var(--clay-dark); text-transform: uppercase; letter-spacing: .04em; }
.buy-card__value { font-family: var(--mono); font-size: 26px; font-weight: 800; color: var(--ink); }

.note-box {
  font-size: 12.5px; color: var(--ink-soft); background: var(--paper-dim); border-left: 3px solid var(--amber);
  padding: 10px 14px; border-radius: 0 var(--radius) var(--radius) 0; margin-top: 16px;
}

/* ---------- PROSE / GUIDE ---------- */
.prose { max-width: 760px; }
.prose h2 { font-size: 22px; margin-top: 34px; }
.prose h3 { font-size: 17px; margin-top: 22px; }
.prose p { color: var(--ink-soft); font-size: 15px; }
.prose strong { color: var(--ink); }
.prose ul { color: var(--ink-soft); font-size: 15px; padding-left: 22px; }
.prose li { margin-bottom: 6px; }
.spec-table { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 13.5px; }
.spec-table th, .spec-table td { text-align: left; padding: 9px 12px; border-bottom: 1px solid var(--line); }
.spec-table th { font-family: var(--mono); font-size: 11px; text-transform: uppercase; letter-spacing: .05em; color: var(--ink-soft); background: var(--paper-dim); }
.spec-table td.mono { font-family: var(--mono); }

.keytake {
  background: var(--chalk); border: 1px solid var(--line); border-left: 4px solid var(--clay);
  border-radius: 0 var(--radius) var(--radius) 0; padding: 16px 18px; margin: 20px 0;
}
.keytake h4 { font-size: 13px; text-transform: uppercase; letter-spacing: .05em; color: var(--clay-dark); margin-bottom: 8px; }
.keytake ul { margin: 0; padding-left: 18px; font-size: 14px; color: var(--ink); }

/* ---------- FOOTER ---------- */
footer.site-foot {
  border-top: 1px solid var(--line); padding: 28px 24px; margin-top: 20px;
  font-size: 12.5px; color: var(--ink-soft); text-align: center;
}

/* ---------- PAGE SWITCH ---------- */
.section-page { display: none; }
.section-page.active { display: block; }

/* ---------- RESPONSIVE ---------- */
@media (max-width: 720px) {
  .burger { display: flex; }
  .nav { display: none; }
  .nav.is-open { display: block; }
  .nav__inner { flex-direction: column; }
  .field-row { grid-template-columns: 1fr; }
}