:root {
  --bg: #f4f7fb;
  --surface: #ffffff;
  --text: #1d2f4e;
  --muted: #4e6487;
  --line: #dbe5f4;
  --line-soft: #e3ebf7;
  --blue-a: #0f5cc4;
  --blue-b: #1b74dc;
  --blue-strong: #234b82;
  --yellow: #ffd646;
  --yellow-border: #efc634;
  --shadow: 0 4px 14px rgba(35, 73, 130, 0.06);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  font-size: 14px;
}

.container {
  width: min(1040px, 92%);
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
}

.nav-wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 0;
}

.brand {
  text-decoration: none;
  color: #17396a;
  font-weight: 800;
}

nav a {
  text-decoration: none;
  color: #37527b;
  font-weight: 600;
  margin-left: 0.9rem;
}

nav {
  display: flex;
  align-items: center;
}

.hero {
  background: linear-gradient(145deg, var(--blue-a), var(--blue-b));
  color: #ffffff;
  padding: 2rem 0 1.7rem;
  border-bottom-left-radius: 14px;
  border-bottom-right-radius: 14px;
  margin-bottom: 1rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  align-items: start;
}

.eyebrow {
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.95);
}

h1 {
  margin: 0.25rem 0 0.55rem;
  line-height: 1.15;
  font-size: clamp(1.3rem, 2.3vw, 1.85rem);
}

.subhead {
  margin: 0;
  max-width: 72ch;
  color: rgba(255, 255, 255, 0.93);
  font-size: 0.93rem;
}

.hero-meta {
  margin: 0.45rem 0 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.82rem;
  font-weight: 600;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.85rem;
}

button {
  cursor: pointer;
}

#startCalculationBtn,
.step-pill.selected {
  background: var(--yellow);
  border: 1px solid var(--yellow-border);
  color: #1f2f4a;
  font-weight: 800;
}

#startCalculationBtn {
  border-radius: 9px;
  padding: 0.45rem 0.9rem;
}

.outline-btn {
  border: 1px solid rgba(255, 255, 255, 0.6);
  color: #ffffff;
  background: rgba(255, 255, 255, 0.14);
  border-radius: 9px;
  padding: 0.45rem 0.9rem;
  font-weight: 700;
}

.section {
  padding: 0.72rem 0;
}

.section h2 {
  margin: 0 0 0.35rem;
  font-size: 1.06rem;
  color: var(--blue-strong);
  line-height: 1.25;
}

.panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: var(--shadow);
}

#calculator > .container > h2 {
  text-align: center;
  margin-bottom: 0.55rem;
}

#calculator .form-panel,
#calculator .result-panel {
  padding: 0.86rem;
}

#calculator .result-panel {
  margin-top: 0.75rem;
}

#calculator .result-panel > h3 {
  margin: 0 0 0.4rem;
  color: var(--blue-strong);
  font-size: 1.03rem;
}

#calculator .input-row-title {
  margin: 0.1rem 0 0.35rem;
  color: var(--blue-strong);
  font-size: 0.98rem;
}

#calculator label {
  display: block;
  margin-bottom: 0.26rem;
  color: #2f4f7d;
  font-size: 0.86rem;
  font-weight: 500;
}

#calculator input,
#calculator select,
#comparisonStepButtons .step-pill {
  width: 100%;
  border: 1px solid #cdd9ee;
  border-radius: 999px;
  background: #ffffff;
  color: #223e67;
  padding: 0.44rem 0.75rem;
  font: inherit;
}

#calculator input:focus,
#calculator select:focus,
#comparisonStepButtons .step-pill:focus {
  outline: none;
  border-color: #5b88ce;
  box-shadow: 0 0 0 3px rgba(68, 118, 200, 0.15);
}

#calculator .product-capture-wrap {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.7rem;
  margin-bottom: 0.62rem;
}

#calculator .capture-box {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: var(--shadow);
  padding: 0.68rem;
}

#calculator .capture-box h4,
#calculator .capture-subtitle {
  margin: 0 0 0.3rem;
  color: var(--blue-strong);
  font-size: 0.94rem;
}

#calculator .capture-subtitle {
  margin-top: 0.5rem;
}

#calculator .capture-fields {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.34rem;
}

#calculator .dimension-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.34rem;
}

#calculator .channel-intro-spacer {
  height: 0.2rem;
  margin: 0;
}

#calculator .channel-guide-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.42rem;
}

#calculator .channel-guide-card {
  width: 100%;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #ffffff;
  padding: 0.52rem 0.42rem;
  text-align: center;
  font-weight: 700;
}

#calculator .channel-guide-card h4 {
  margin: 0;
  font-size: 0.84rem;
  color: #234b82;
}

#calculator .channel-guide-card.selected {
  background: var(--yellow);
  border-color: var(--yellow-border);
}

#calculator .channel-guide-card.selected h4 {
  color: #1f2f4a;
}

#calculator .error {
  color: #c93a3a;
  min-height: 1rem;
  margin-top: 0.45rem;
  font-size: 0.84rem;
}

#calculator .breakdown {
  margin-top: 0.28rem;
  border-top: 1px dashed #d8e2f1;
}

#calculator .breakdown-row {
  display: flex;
  justify-content: space-between;
  gap: 0.65rem;
  padding: 0.4rem 0;
  border-bottom: 1px dashed #d9e4f2;
  color: #233f66;
  font-size: 0.84rem;
}

#calculator .breakdown-row strong {
  white-space: nowrap;
}

#calculator .strong-row span,
#calculator .strong-row strong {
  font-weight: 800;
}

#calculator .negative-row strong {
  color: #c23b3b;
}

#calculator .breakdown-detail {
  border-bottom: 1px dashed #d9e4f2;
}

#calculator .breakdown-detail > summary {
  list-style: none;
  cursor: pointer;
}

#calculator .breakdown-detail > summary::-webkit-details-marker {
  display: none;
}

#calculator .breakdown-detail > summary.breakdown-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

#calculator .detail-title {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-weight: 600;
}

#calculator .detail-title::before {
  content: "+";
  color: #607ca6;
  font-size: 0.74rem;
  font-weight: 700;
}

#calculator .breakdown-detail[open] .detail-title::before {
  content: "-";
}

#calculator .detail-body {
  margin: 0.18rem 0 0.32rem;
  padding: 0.28rem 0.45rem;
  background: #f8fbff;
  border: 1px solid #dce6f5;
  border-left: 2px solid #dce6f5;
  border-radius: 8px;
}

#calculator .slab-table-wrap {
  margin-top: 0.3rem;
}

#calculator .slab-table {
  width: 100%;
  border-collapse: collapse;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

#calculator .slab-table th,
#calculator .slab-table td {
  border: 1px solid var(--line-soft);
  padding: 0.35rem 0.45rem;
  text-align: left;
  font-size: 0.84rem;
}

#calculator .slab-table thead th {
  background: #edf3fd;
  color: #2e4b77;
  font-weight: 700;
}

#calculator .active-slab-row td {
  background: #fff6d6;
}

#calculator .channel-compare-wrap {
  margin-top: 0.45rem;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #ffffff;
}

#calculator .channel-table {
  width: 100%;
  min-width: 560px;
  border-collapse: collapse;
}

#calculator .channel-table th,
#calculator .channel-table td {
  padding: 0.4rem 0.45rem;
  border-bottom: 1px solid var(--line-soft);
  text-align: left;
  font-size: 0.84rem;
}

#calculator .channel-table thead th {
  background: #edf3fd;
  color: #2e4b77;
  font-weight: 700;
}

#calculator .channel-table tr.active-channel td {
  background: #fff6d6;
  color: #2a446a;
}

#calculator .compare-sub-row td {
  background: #f8fbff;
  color: #355682;
}

#calculator .compare-sub-row td:first-child {
  padding-left: 1.05rem;
}

#calculator .compare-main-label {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-weight: 700;
}

#calculator .compare-toggle {
  width: 18px;
  min-width: 18px;
  height: 18px;
  margin: 0;
  padding: 0;
  border-radius: 999px;
  border: 1px solid #bfd0ea;
  background: #ffffff;
  color: #365985;
  font-size: 0.72rem;
  font-weight: 800;
  line-height: 1;
}

#calculator .compare-controls {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  margin-top: 0.6rem;
  flex-wrap: wrap;
}

#calculator .step-level-label {
  color: #2f4f7d;
  font-size: 0.84rem;
  font-weight: 600;
}

#calculator .step-level-buttons {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
}

.step-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #ffffff;
  color: #2e4b77;
  padding: 0.32rem 0.78rem;
  font-size: 0.82rem;
  font-weight: 700;
  text-decoration: none;
}

#comparisonStepButtons .step-pill {
  width: auto;
  padding: 0.34rem 0.82rem;
}

#faq h2 {
  margin-bottom: 0.45rem;
}

#faq details {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.55rem;
  margin-bottom: 0.42rem;
}

#faq summary {
  cursor: pointer;
  color: #111111;
  font-weight: 700;
  font-size: 0.86rem;
}

#faq p,
#faq li,
#faq div {
  color: #111111;
  font-size: 0.88rem;
  font-weight: 600;
}

#related-pages .related-pages-panel {
  padding: 0.85rem;
}

#related-pages h2 {
  margin-bottom: 0.25rem;
}

#related-pages .related-pages-subhead {
  margin: 0 0 0.5rem;
  font-size: 0.84rem;
  color: #4e6487;
}

#related-pages .related-pages-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

#related-pages .related-pages-list li {
  margin: 0 0 0.32rem 0;
}

#related-pages .related-pages-list a {
  display: block;
  text-decoration: none;
  color: #2f4f7d;
  font-size: 0.74rem;
  font-weight: 700;
  line-height: 1.3;
  border: 1px solid #dbe5f4;
  background: #ffffff;
  border-radius: 9px;
  padding: 0.4rem 0.55rem;
}

#related-pages .related-pages-list a:hover {
  background: #f4f8ff;
  color: #1f3f6f;
}

.site-footer {
  padding: 1rem 0 1.25rem;
}

.footer-wrap {
  display: flex;
  justify-content: space-between;
  gap: 0.8rem;
  flex-wrap: wrap;
  color: #4e6487;
  font-size: 0.84rem;
}

@media (max-width: 960px) {
  #calculator .product-capture-wrap {
    grid-template-columns: 1fr;
  }

  #calculator .dimension-grid {
    grid-template-columns: 1fr;
  }

  #calculator .channel-guide-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  #calculator .compare-controls {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 640px) {
  nav {
    gap: 0.55rem;
  }

  nav a {
    margin-left: 0;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  #startCalculationBtn,
  .outline-btn {
    width: 100%;
  }

  #calculator .channel-guide-grid {
    grid-template-columns: 1fr;
  }
}