:root {
  --c-bg: #f7f6f2;
  --c-surface: #ffffff;
  --c-text: #1f2328;
  --c-muted: #5b6370;
  --c-primary: #b2461b;
  --c-primary-dark: #8a3412;
  --c-border: #dcd8cf;
  --c-note: #fff6e0;
  --c-error: #b42318;
  --radius: 10px;
  --maxw: 960px;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  color: var(--c-text);
  background: var(--c-bg);
}

a { color: var(--c-primary-dark); }
a:hover { color: var(--c-primary); }

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: #000; color: #fff; padding: 8px 12px; z-index: 10;
}
.skip-link:focus { left: 8px; top: 8px; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 16px; }

.site-header { background: var(--c-surface); border-bottom: 1px solid var(--c-border); }
.site-header .container {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: 8px; padding-top: 10px; padding-bottom: 10px;
}
.brand { font-weight: 700; font-size: 1.1rem; text-decoration: none; color: var(--c-text); }
.brand span { color: var(--c-primary); }
.site-nav ul { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 4px 14px; }
.site-nav a { text-decoration: none; font-weight: 500; padding: 6px 0; display: inline-block; }
.site-nav a[aria-current="page"] { color: var(--c-primary); border-bottom: 2px solid var(--c-primary); }

main { padding: 20px 0 40px; }

h1 { font-size: 1.6rem; line-height: 1.3; margin: 0.4em 0 0.5em; }
h2 { font-size: 1.3rem; line-height: 1.35; margin: 1.6em 0 0.5em; }
h3 { font-size: 1.1rem; margin: 1.2em 0 0.4em; }

.lead { font-size: 1.08rem; color: var(--c-muted); }

.breadcrumb { font-size: 0.9rem; color: var(--c-muted); margin: 0; }
.breadcrumb a { color: var(--c-muted); }

.card-grid { display: grid; grid-template-columns: 1fr; gap: 14px; padding: 0; list-style: none; }
@media (min-width: 680px) { .card-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .card-grid.three { grid-template-columns: repeat(3, 1fr); } }

.card {
  background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius);
  padding: 16px;
}
.card h3 { margin-top: 0; }
.card p { margin: 0.3em 0 0.8em; color: var(--c-muted); }

.btn {
  display: inline-block; background: var(--c-primary); color: #fff; border: 0;
  border-radius: 8px; padding: 12px 18px; font-size: 1rem; font-weight: 600;
  text-decoration: none; cursor: pointer; min-height: 44px;
}
.btn:hover, .btn:focus { background: var(--c-primary-dark); color: #fff; }
.btn.secondary { background: transparent; color: var(--c-primary-dark); border: 1px solid var(--c-primary-dark); }

.note {
  background: var(--c-note); border-left: 4px solid #e0a100; padding: 12px 14px;
  border-radius: 6px; margin: 16px 0;
}

/* Biểu mẫu công cụ */
.tool { background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius); padding: 16px; }
fieldset { border: 1px solid var(--c-border); border-radius: 8px; margin: 0 0 16px; padding: 12px; }
legend { font-weight: 600; padding: 0 6px; }
.field { margin-bottom: 12px; }
.field label { display: block; font-weight: 600; margin-bottom: 4px; }
.field .hint { display: block; font-size: 0.88rem; color: var(--c-muted); font-weight: 400; }
input[type="text"], input[type="number"], select {
  width: 100%; font-size: 1rem; padding: 10px; border: 1px solid #b9b4a8; border-radius: 6px;
  background: #fff; min-height: 44px;
}
input:focus, select:focus, .btn:focus { outline: 3px solid #f2b179; outline-offset: 1px; }
.row-2 { display: grid; grid-template-columns: 1fr; gap: 0 12px; }
@media (min-width: 560px) { .row-2 { grid-template-columns: 1fr 1fr; } .row-3 { grid-template-columns: 1fr 1fr 1fr; } }
.row-3 { display: grid; grid-template-columns: 1fr 1fr; gap: 0 12px; }

.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 8px; }

.result { margin-top: 18px; padding: 14px; border-radius: 8px; background: #eef6ee; border: 1px solid #b8d8b8; }
.result[hidden] { display: none; }
.result .big { font-size: 1.35rem; font-weight: 700; }
.error { color: var(--c-error); font-weight: 600; margin-top: 10px; }

.table-wrap { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; font-size: 0.95rem; }
th, td { border: 1px solid var(--c-border); padding: 6px 8px; text-align: left; }
td.num, th.num { text-align: right; white-space: nowrap; }

.part-row { border: 1px dashed var(--c-border); border-radius: 8px; padding: 10px; margin-bottom: 10px; }
.part-row .remove { margin-top: 4px; }

article.prose { background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius); padding: 16px 18px; }
article.prose li { margin-bottom: 0.3em; }

.site-footer { border-top: 1px solid var(--c-border); background: var(--c-surface); padding: 20px 0; font-size: 0.92rem; color: var(--c-muted); }
.site-footer ul { list-style: none; padding: 0; margin: 8px 0; display: flex; flex-wrap: wrap; gap: 6px 16px; }

/* Bảng tính dự toán sơ bộ */
fieldset[hidden] { display: none; }
.choice { display: flex; align-items: center; gap: 10px; min-height: 44px; }
.choice input { width: 22px; height: 22px; margin: 0; accent-color: var(--c-primary); }
.choice label { font-weight: 600; cursor: pointer; }
.span-all { grid-column: 1 / -1; }
.result-title { margin-top: 0; }
caption { text-align: left; font-weight: 600; padding: 8px 0 4px; }
.table-wrap[hidden] { display: none; }
.result tfoot th { font-weight: 600; }
.warn { color: #8a5a00; font-weight: 600; }
.warn[hidden] { display: none; }
@media (max-width: 559px) { .span-all-sm { grid-column: 1 / -1; } }

@media print {
  .site-header, .site-footer, .skip-link, .note, .breadcrumb, .actions, fieldset, main > .container > h2,
  main > .container > h3, main > .container > ul, main > .container > p { display: none !important; }
  .tool, .result { border: 0; background: #fff; padding: 0; }
  body { background: #fff; font-size: 12pt; }
}
.draft { margin: 12px 0; }
.draft summary { cursor: pointer; font-weight: 600; min-height: 44px; display: flex; align-items: center; }
#vat-row[hidden] { display: none; }
@media print { .draft { display: none; } }
.sub { margin-top: 14px; }
.sub summary { cursor: pointer; font-weight: 600; min-height: 44px; display: flex; align-items: center; }
#budget-wrap[hidden] { display: none; }
#budget-wrap h3 { margin-top: 0.8em; }
.echo { display: block; font-size: 0.88rem; color: var(--c-muted); min-height: 1.2em; margin-top: 2px; }
.echo.bad { color: var(--c-error); font-weight: 600; }
.result-title:focus { outline: none; }
#steps li { margin-bottom: 0.3em; overflow-wrap: anywhere; }

/* Điện thoại: bảng kết quả xếp thành khối dọc theo từng dòng, nhãn cột lấy từ data-label. */
@media screen and (max-width: 559px) {
  table.stack thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  table.stack tbody tr { display: block; border: 1px solid var(--c-border); border-radius: 6px; margin-bottom: 8px; background: #fff; }
  table.stack tbody td { display: flex; justify-content: space-between; gap: 12px; border: 0; border-bottom: 1px dashed var(--c-border); text-align: right; white-space: normal; }
  table.stack tbody td:last-child { border-bottom: 0; }
  table.stack tbody td:empty { display: none; }
  table.stack tbody td::before { content: attr(data-label); font-weight: 600; text-align: left; color: var(--c-muted); }
  table.stack tbody td:first-child { font-weight: 700; text-align: left; }
  table.stack tbody td:first-child::before { content: none; }
  table.stack tfoot tr { display: flex; flex-wrap: wrap; align-items: baseline; border-top: 1px solid var(--c-border); }
  table.stack tfoot th, table.stack tfoot td { border: 0; }
  table.stack tfoot th:first-child { flex: 1 1 100%; padding-bottom: 0; }
  table.stack tfoot th.num { flex: 1 1 auto; }
  table.stack tfoot tr[hidden] { display: none; }
}
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
#share-url { width: 100%; margin-top: 8px; font-size: 16px; }
@media print { #reset-btn { display: none; } }

/* Thanh tổng tiền cố định khi bảng dự toán tự tính lại */
.live-bar {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 5;
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 4px 12px;
  padding: 10px 16px calc(10px + env(safe-area-inset-bottom));
  background: var(--c-surface); border-top: 2px solid var(--c-primary);
  box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.12); font-weight: 700;
}
.live-bar[hidden] { display: none; }
.live-bar a { min-height: 44px; display: inline-flex; align-items: center; }
body.has-live-bar { padding-bottom: 72px; }
@media print { .live-bar { display: none !important; } body.has-live-bar { padding-bottom: 0; } }

.figure { margin: 12px 0 16px; padding: 12px; background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius); }
.figure svg { display: block; width: 100%; height: auto; max-width: 640px; margin: 0 auto; }
.figure figcaption { font-size: 0.9rem; color: var(--c-muted); margin-top: 8px; }
.share-box { margin-top: 14px; padding-top: 12px; border-top: 1px solid #b8d8b8; }
.h-small { font-size: 1.05rem; margin: 0 0 4px; }
.share-box input[type="text"], .share-box textarea { width: 100%; margin-top: 8px; font: inherit; font-size: 0.92rem; }
.share-box textarea { padding: 10px; border: 1px solid #b9b4a8; border-radius: 6px; background: #fff; }
.share-box [hidden] { display: none; }

/* Mục lục và câu hỏi thường gặp trên trang công cụ */
.toc { background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius); padding: 10px 14px; margin: 12px 0 16px; }
.toc p { margin: 0 0 4px; font-weight: 600; }
.toc ul { margin: 0; padding-left: 1.2em; }
.toc li { margin: 2px 0; }
.faq { background: var(--c-surface); border: 1px solid var(--c-border); border-radius: 8px; padding: 0 14px; margin: 8px 0; }
.faq summary { cursor: pointer; font-weight: 600; min-height: 44px; display: flex; align-items: center; }
.faq p { margin: 0 0 12px; }
@media print { .toc, .faq { display: none; } }

/* Tối ưu tải trang và điện thoại */
main > .container > h2, main > .container > h3 { scroll-margin-top: 8px; }
main > .container > .figure, main > .container > .faq, main > .container > .toc { content-visibility: auto; contain-intrinsic-size: auto 240px; }
@media (max-width: 559px) {
  body { font-size: 16px; }
  h1 { font-size: 1.4rem; }
  .tool { padding: 12px; }
  .part-row .row-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0 8px; }
  .part-row .row-3 .field label { font-size: 0.9rem; }
  .actions .btn { flex: 1 1 100%; text-align: center; }
  .site-nav ul { gap: 0 12px; }
  .site-nav a { padding: 10px 0; }
}
input, button, select, textarea { touch-action: manipulation; }

/* Vùng chạm tối thiểu 48px cho nút, ô nhập, mục bấm được */
.btn, input[type="text"], input[type="number"], select { min-height: 48px; }
.btn { display: inline-flex; align-items: center; justify-content: center; }
.choice, .draft summary, .sub summary, .faq summary, .live-bar a { min-height: 48px; }
.site-nav a { min-height: 48px; display: inline-flex; align-items: center; padding: 0; }
.brand { display: inline-flex; align-items: center; min-height: 48px; }
.toc a, .breadcrumb a { display: inline-block; padding: 12px 0; }
.toc li { margin: 0; }
.breadcrumb a { padding: 12px 4px; }
.site-footer a { display: inline-block; padding: 13px 0; }
td .btn { min-height: 48px; white-space: nowrap; }
@media (max-width: 559px) { .site-nav a { padding: 0; } }

/* CTA nổi bật nhận báo giá dự toán */
.cta-card {
  background: linear-gradient(135deg, #fffaf7 0%, #fff2eb 100%);
  border: 2px solid var(--c-primary);
  border-radius: var(--radius);
  padding: 20px;
  margin: 24px 0;
  box-shadow: 0 4px 14px rgba(178, 70, 27, 0.08);
}
.cta-card h2, .cta-card h3 {
  margin-top: 0;
  margin-bottom: 8px;
  color: var(--c-primary-dark);
}
.cta-card p {
  margin: 0 0 14px;
}
.cta-card .cta-note {
  margin-top: 12px;
  margin-bottom: 0;
  font-size: 0.88rem;
  color: var(--c-muted);
}
.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}
.btn-cta {
  background: var(--c-primary);
  color: #fff;
  font-size: 1.02rem;
  font-weight: 700;
  padding: 12px 22px;
  border-radius: 8px;
  text-decoration: none;
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 6px rgba(178, 70, 27, 0.25);
  transition: background 0.15s, transform 0.1s;
}
.btn-cta:hover, .btn-cta:focus {
  background: var(--c-primary-dark);
  color: #fff;
  transform: translateY(-1px);
}
@media (max-width: 559px) {
  .cta-card {
    padding: 14px;
    margin: 16px 0;
  }
  .cta-actions .btn, .cta-actions .btn-cta {
    flex: 1 1 100%;
    text-align: center;
    justify-content: center;
  }
}

/* Khối dự toán nhanh và CTA tư vấn */
.quick-calc-hero {
  background: linear-gradient(135deg, #ffffff 0%, #fff8f5 100%);
  border: 2px solid var(--c-primary);
  border-radius: var(--radius);
  padding: 24px;
  margin: 20px 0 28px;
  box-shadow: 0 4px 16px rgba(178, 70, 27, 0.08);
}
.quick-calc-hero h2 {
  margin-top: 4px;
  margin-bottom: 10px;
  color: var(--c-primary-dark);
  font-size: 1.45rem;
}
.quick-calc-features {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin: 16px 0 20px;
  padding: 0;
  list-style: none;
}
@media (min-width: 600px) {
  .quick-calc-features {
    grid-template-columns: 1fr 1fr;
  }
}
.quick-calc-feature {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  background: #ffffff;
  border: 1px solid var(--c-border);
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 0.95rem;
}
.quick-calc-feature-icon {
  font-size: 1.25rem;
  line-height: 1.2;
  flex-shrink: 0;
}
.quick-calc-feature-text strong {
  display: block;
  color: var(--c-text);
  font-size: 0.98rem;
}
.quick-calc-feature-text span {
  font-size: 0.88rem;
  color: var(--c-muted);
}
.cta-badge-tag {
  display: inline-block;
  background: var(--c-primary);
  color: #ffffff;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 999px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}
.cta-privacy {
  font-size: 0.84rem;
  color: var(--c-muted);
  margin-top: 12px;
  margin-bottom: 0;
  line-height: 1.45;
}
.cta-privacy a {
  color: var(--c-muted);
  text-decoration: underline;
}
.cta-privacy a:hover {
  color: var(--c-primary);
}

/* Khối CTA ngay trong kết quả tính toán */
.result-cta-card {
  background: #ffffff;
  border: 2px solid #b8d8b8;
  border-left: 6px solid var(--c-primary);
  border-radius: 8px;
  padding: 18px;
  margin: 20px 0 14px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}
.result-cta-card h3 {
  margin-top: 2px;
  margin-bottom: 8px;
  color: var(--c-primary-dark);
  font-size: 1.18rem;
}
.result-cta-card p {
  margin: 0 0 14px;
  color: var(--c-text);
  font-size: 0.96rem;
}

/* Thẻ dự toán vật tư cấp phối và danh sách điều hướng công cụ */
.materials-card {
  background: #ffffff;
  border: 1px solid #b8d8b8;
  border-radius: 8px;
  padding: 16px;
  margin: 18px 0 14px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.04);
}
.materials-card h3 {
  margin-top: 0;
  margin-bottom: 6px;
  color: var(--c-primary-dark);
  font-size: 1.15rem;
}
.materials-card .table-wrap {
  margin-top: 10px;
}
.next-tools-list {
  list-style: none;
  padding: 0;
  margin: 12px 0 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.next-tools-list li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.next-tools-list .btn {
  text-align: left;
  justify-content: flex-start;
  font-size: 0.95rem;
}
@media (min-width: 600px) {
  .next-tools-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }
}

/* Nâng cấp phản hồi live bar trên thiết bị di động */
.live-bar {
  background: #ffffff;
  box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.14);
}
#live-total {
  color: var(--c-primary-dark);
  font-size: 1.05rem;
  letter-spacing: -0.2px;
}
#live-show {
  background: var(--c-primary);
  color: #ffffff;
  padding: 8px 16px;
  border-radius: 6px;
  font-size: 0.94rem;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.15s;
}
#live-show:hover, #live-show:focus {
  background: var(--c-primary-dark);
  color: #ffffff;
}

/* Nâng cao trải nghiệm nhập liệu & tương tác di động */
input[type="text"], input[type="number"], select {
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
input[type="text"]:focus, input[type="number"]:focus, select:focus {
  border-color: var(--c-primary);
  box-shadow: 0 0 0 3px rgba(178, 70, 27, 0.25);
  outline: none;
}
.btn:active, .btn-cta:active {
  transform: scale(0.98);
}
@media (max-width: 559px) {
  .quick-calc-hero {
    padding: 16px;
    margin: 16px 0 20px;
  }
  .result-cta-card {
    padding: 14px;
  }
}

/* Khung đơn giá thị trường 2026 và form liên hệ nhanh */
.price-source-note {
  font-size: 0.92rem;
  color: var(--c-muted);
  margin-top: 10px;
}
.example-preset-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 16px 0 20px;
}
.btn-preset {
  background: #ffffff;
  border: 1px solid var(--c-primary);
  color: var(--c-primary-dark);
  font-size: 0.92rem;
  font-weight: 600;
  padding: 9px 14px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s ease;
  line-height: 1.35;
}
.btn-preset:hover, .btn-preset:focus {
  background: var(--c-primary);
  color: #ffffff;
}
.lead-form-box {
  background: #ffffff;
  border: 1px solid var(--c-border);
  border-radius: 8px;
  padding: 18px 20px;
  margin-top: 18px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}
.lead-form-box h3 {
  margin-top: 0;
  margin-bottom: 6px;
  font-size: 1.15rem;
  color: var(--c-primary-dark);
}
.field-checkbox {
  margin: 12px 0 16px;
  font-size: 0.9rem;
  color: var(--c-text);
}
.field-checkbox label {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-weight: normal;
  cursor: pointer;
  line-height: 1.45;
}
.field-checkbox input[type="checkbox"] {
  margin-top: 3px;
  flex-shrink: 0;
}
.lead-status-msg {
  padding: 12px 14px;
  border-radius: 6px;
  margin-top: 14px;
  font-size: 0.94rem;
  line-height: 1.45;
}
.lead-status-msg.success {
  background: #eef7ee;
  border: 1px solid #7cb37c;
  color: #1e5c1e;
}
.lead-status-msg.error {
  background: #fdeeee;
  border: 1px solid #e08e8e;
  color: #9c1c1c;
}
@media (max-width: 559px) {
  .lead-form-box {
    padding: 14px;
  }
  .btn-preset {
    flex: 1 1 100%;
    text-align: center;
  }
  .quick-calc-box {
    padding: 12px;
  }
  .qc-highlight {
    font-size: 1.1rem;
  }
}

/* Khối tính nhanh khối lượng & khoảng chi phí xây thô tham chiếu */
.quick-calc-box {
  background: #fdfaf7;
  border: 1px solid #eed6cc;
  border-left: 4px solid var(--c-primary);
  border-radius: 8px;
  padding: 14px 16px;
  margin: 14px 0 10px;
}
.quick-calc-box p {
  margin: 0 0 8px;
}
.quick-calc-box p:last-child {
  margin-bottom: 0;
}
.qc-price-range {
  margin-top: 10px;
  font-size: 0.98rem;
  line-height: 1.45;
}
.qc-highlight {
  display: inline-block;
  margin-top: 4px;
  font-size: 1.22rem;
  font-weight: 700;
  color: var(--c-primary-dark);
}
.btn-submit-lead {
  font-size: 1rem;
  font-weight: 700;
  padding: 10px 20px;
  background: var(--c-primary);
  color: #ffffff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
}
.btn-submit-lead:hover, .btn-submit-lead:focus {
  background: var(--c-primary-dark);
}

img { max-width: 100%; height: auto; }
img[loading="lazy"] { content-visibility: auto; }

/* Phiếu yêu cầu báo giá (công cụ diện tích quy đổi) */
.lead-form-box textarea { width: 100%; font: inherit; font-size: 0.92rem; padding: 10px; border: 1px solid #b9b4a8; border-radius: 6px; background: #fff; }
.lead-form-box textarea[hidden] { display: none; }