/* =========================================
   NicheCalc — Mobile-first, clean, fast
   ========================================= */

/* Reset */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --text: #1a1a2e;
  --text-muted: #555;
  --text-light: #777;
  --bg: #ffffff;
  --bg-alt: #f8f9fa;
  --border: #e2e8f0;
  --accent: #2563EB;
  --accent-hover: #1d4ed8;
  --accent-light: #eff6ff;
  --green: #059669;
  --green-light: #d1fae5;
  --radius: 8px;
  --max-width: 800px;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }

/* Layout */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.page-content {
  padding: 40px 0 60px;
  min-height: calc(100vh - 200px);
}

/* ====== HEADER / NAV ====== */
.site-header {
  border-bottom: 2px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}
.logo:hover { text-decoration: none; color: var(--text); }

.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--accent);
  color: #fff;
  border-radius: 6px;
  font-weight: 700;
  font-size: 0.9rem;
}

/* Desktop nav links */
.nav-links {
  display: flex;
  list-style: none;
  gap: 24px;
  align-items: center;
}
.nav-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  padding: 4px 0;
}
.nav-links a:hover { color: var(--accent); text-decoration: none; }

/* Mobile hamburger */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  min-width: 44px;
  min-height: 44px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  margin: 5px auto;
  transition: 0.2s;
}

@media (max-width: 640px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 2px solid var(--border);
    padding: 16px 20px;
    gap: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
  }
  .nav-links.open { display: flex; }
  .nav-links a { font-size: 1rem; padding: 8px 0; }
  .site-header { position: relative; }
}

/* ====== FOOTER ====== */
.site-footer {
  border-top: 2px solid var(--border);
  padding: 32px 0;
  margin-top: 40px;
  background: var(--bg-alt);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 24px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  list-style: none;
}
.footer-links a {
  color: var(--text-muted);
  font-size: 0.85rem;
}
.footer-links a:hover { color: var(--accent); }

/* ====== HOMEPAGE ====== */
.hero-section {
  padding: 48px 0 40px;
  text-align: center;
}

.hero-section h1 {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 12px;
}
.hero-section h1 .highlight { color: var(--accent); }

.hero-section .subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto;
}

@media (min-width: 640px) {
  .hero-section { padding: 64px 0 48px; }
  .hero-section h1 { font-size: 2.5rem; }
}

/* Category Cards Grid */
.categories-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin: 32px 0;
}

@media (min-width: 500px) {
  .categories-grid { grid-template-columns: 1fr 1fr; }
}

.category-card {
  display: block;
  padding: 24px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s;
}
.category-card:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  text-decoration: none;
  color: var(--text);
}

.category-card .card-icon {
  font-size: 1.5rem;
  margin-bottom: 8px;
}
.category-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 4px;
}
.category-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ====== CATEGORY PAGE ====== */
.category-header {
  padding: 40px 0 24px;
}
.category-header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.category-header p {
  color: var(--text-muted);
  font-size: 1rem;
}

.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 16px;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--accent); }

.calculator-list {
  list-style: none;
  margin: 24px 0;
}
.calculator-list li {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
}
.calculator-list li a {
  display: block;
  padding: 20px 24px;
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.calculator-list li a:hover {
  background: var(--bg-alt);
  text-decoration: none;
}
.calculator-list .arrow {
  color: var(--text-light);
  font-size: 1.2rem;
}

.empty-state {
  text-align: center;
  padding: 48px 0;
  color: var(--text-muted);
}
.empty-state p {
  font-size: 1rem;
  margin-bottom: 8px;
}

/* ====== CALCULATOR PAGE ====== */
.calculator-page {
  padding: 40px 0;
}
.calculator-page h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.calculator-placeholder {
  background: var(--bg-alt);
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 48px 24px;
  text-align: center;
  margin: 24px 0;
}
.calculator-placeholder .icon {
  font-size: 2.5rem;
  margin-bottom: 12px;
}
.calculator-placeholder h2 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 8px;
}
.calculator-placeholder p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ====== STATIC PAGES (about, legal, etc.) ====== */
.static-page {
  padding: 40px 0 60px;
}
.static-page h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 24px;
  line-height: 1.3;
}
.static-page h2 {
  font-size: 1.3rem;
  font-weight: 600;
  margin: 32px 0 12px;
  color: var(--text);
}
.static-page h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 24px 0 8px;
}
.static-page p {
  margin-bottom: 16px;
  line-height: 1.7;
}
.static-page ul, .static-page ol {
  margin: 0 0 16px 24px;
  line-height: 1.7;
}
.static-page li { margin-bottom: 6px; }

.static-page .last-updated {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 24px;
}

/* ====== CONTACT FORM ====== */
.form-group {
  margin-bottom: 20px;
}
.form-group label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 6px;
}
.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: var(--font);
  font-size: 1rem;
  color: var(--text);
  background: var(--bg);
  min-height: 44px;
  transition: border-color 0.15s;
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-light);
}
.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 600;
  font-family: var(--font);
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  min-height: 44px;
  min-width: 44px;
  transition: background 0.15s, transform 0.1s;
}
.btn:active { transform: scale(0.98); }

.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: var(--accent-hover); }

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.btn-outline:hover { background: var(--accent-light); }

.form-success {
  background: var(--green-light);
  color: var(--green);
  padding: 14px 16px;
  border-radius: var(--radius);
  font-weight: 500;
  margin-bottom: 20px;
}
.form-error {
  background: #fef2f2;
  color: #b91c1c;
  padding: 14px 16px;
  border-radius: var(--radius);
  font-weight: 500;
  margin-bottom: 20px;
}

/* ====== COMING SOON PAGES ====== */
.coming-soon {
  text-align: center;
  padding: 80px 0;
}
.coming-soon .icon {
  font-size: 3rem;
  margin-bottom: 16px;
}
.coming-soon h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.coming-soon p {
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 480px;
  margin: 0 auto 24px;
}

/* ====== 404 PAGE ====== */
.not-found {
  text-align: center;
  padding: 80px 0;
}
.not-found .big-404 {
  font-size: 6rem;
  font-weight: 800;
  color: var(--border);
  line-height: 1;
  margin-bottom: 16px;
}
.not-found h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.not-found p {
  color: var(--text-muted);
  margin-bottom: 24px;
}
.not-found .links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

/* ====== UTILITIES ====== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

.text-center { text-align: center; }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }

/* ====== CONCRETE CALCULATOR TOOL ====== */
.calc-tool {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin: 24px 0 32px;
}

.calc-tool-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text);
}

/* Unit toggle */
.unit-toggle {
  display: flex;
  margin-bottom: 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  width: fit-content;
}

.unit-toggle button {
  padding: 10px 20px;
  background: var(--bg);
  border: none;
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  color: var(--text-muted);
  min-height: 44px;
  transition: background 0.15s, color 0.15s;
}

.unit-toggle button.active {
  background: var(--accent);
  color: #fff;
}

/* Inputs grid */
.calc-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 16px;
}

@media (max-width: 480px) {
  .calc-inputs { grid-template-columns: 1fr; }
}

.ci-group {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.ci-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.ci-input-wrap {
  position: relative;
  display: flex;
  align-items: center;
}

.ci-input-wrap input {
  width: 100%;
  padding: 11px 52px 11px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  min-height: 44px;
  transition: border-color 0.15s;
  -moz-appearance: textfield;
}

.ci-input-wrap input::-webkit-outer-spin-button,
.ci-input-wrap input::-webkit-inner-spin-button {
  -webkit-appearance: none;
}

.ci-input-wrap input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-light);
}

.ci-unit {
  position: absolute;
  right: 12px;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-light);
  pointer-events: none;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

/* Calculate button */
.calc-action-row {
  display: flex;
  gap: 10px;
  margin-top: 4px;
  flex-wrap: wrap;
}

.btn-calculate {
  flex: 1 1 160px;
  background: var(--accent);
  color: #fff;
  padding: 13px;
  border: none;
  border-radius: var(--radius);
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  min-height: 44px;
  transition: background 0.15s;
}

.btn-calculate:hover { background: var(--accent-hover); }
.btn-calculate:active { transform: scale(0.99); }

.btn-clear {
  flex: 0 0 auto;
  background: transparent;
  color: var(--accent);
  padding: 13px 22px;
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  min-height: 44px;
  transition: background 0.15s, color 0.15s;
}

.btn-clear:hover { background: var(--accent-light); }
.btn-clear:active { transform: scale(0.99); }

/* Validation errors */
.input-invalid {
  border-color: #ef4444 !important;
  background-color: #fff5f5 !important;
  box-shadow: 0 0 0 2px rgba(239,68,68,0.15) !important;
}

.ci-field-error {
  font-size: 0.78rem;
  color: #ef4444;
  margin-top: 3px;
  font-weight: 500;
  line-height: 1.4;
}

/* Results */
.calc-results {
  background: #fff;
  border: 2px solid var(--green);
  border-radius: var(--radius);
  padding: 20px;
  margin-top: 20px;
}

.results-heading {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--green);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}

.volume-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 12px;
  margin-bottom: 20px;
}

@media (max-width: 480px) {
  .volume-grid { grid-template-columns: 1fr; }
}

.vol-item {
  text-align: center;
  background: var(--green-light);
  border-radius: 6px;
  padding: 14px 10px;
}

.vol-item.primary .vol-val {
  font-size: 2.2rem;
}

.vol-val {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--green);
  line-height: 1.1;
}

.vol-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 4px;
  font-weight: 500;
}

/* Bag counts */
.bags-section {
  border-top: 1px solid var(--border);
  padding-top: 16px;
  margin-bottom: 16px;
}

.bags-heading {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.bags-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

@media (max-width: 480px) {
  .bags-grid { grid-template-columns: 1fr; }
}

.bag-item {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 8px;
  text-align: center;
  background: var(--bg-alt);
}

.bag-count {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.1;
}

.bag-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 3px;
}

/* Cost estimator */
.cost-section {
  border-top: 1px solid var(--border);
  padding-top: 16px;
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.cost-input-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.cost-input-row label {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-muted);
  white-space: nowrap;
}

.cost-input-row input {
  width: 88px;
  padding: 9px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  min-height: 44px;
  -moz-appearance: textfield;
}

.cost-input-row input::-webkit-outer-spin-button,
.cost-input-row input::-webkit-inner-spin-button {
  -webkit-appearance: none;
}

.cost-input-row input:focus {
  outline: none;
  border-color: var(--accent);
}

.cost-result-box {
  display: flex;
  flex-direction: column;
}

.cost-amount {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1;
}

.cost-note {
  font-size: 0.75rem;
  color: var(--text-light);
  margin-top: 2px;
}

.waste-note {
  font-size: 0.78rem;
  color: var(--text-light);
  margin-top: 14px;
  font-style: italic;
}

/* ====== SEO CONTENT BELOW CALCULATOR ====== */
.seo-content {
  margin-top: 48px;
  padding-top: 40px;
  border-top: 2px solid var(--border);
}

.seo-content h2 {
  font-size: 1.45rem;
  font-weight: 700;
  margin: 40px 0 14px;
  color: var(--text);
  line-height: 1.3;
}

.seo-content h2:first-child {
  margin-top: 0;
}

.seo-content h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 24px 0 10px;
  color: var(--text);
}

.seo-content p {
  margin-bottom: 16px;
  line-height: 1.75;
  color: var(--text);
}

.seo-content ul, .seo-content ol {
  margin: 0 0 16px 24px;
  line-height: 1.75;
}

.seo-content li {
  margin-bottom: 6px;
}

.formula-box {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 16px 20px;
  margin: 16px 0;
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--text);
}

.formula-box strong {
  color: var(--accent);
}

/* Project comparison table */
.project-table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  font-size: 0.875rem;
  overflow-x: auto;
  display: block;
}

.project-table thead tr {
  background: var(--bg-alt);
}

.project-table th {
  border: 1px solid var(--border);
  padding: 11px 14px;
  text-align: left;
  font-weight: 600;
  font-size: 0.82rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.project-table td {
  border: 1px solid var(--border);
  padding: 11px 14px;
  vertical-align: middle;
}

.project-table tr:nth-child(even) td {
  background: var(--bg-alt);
}

.project-table tr:hover td {
  background: var(--accent-light);
}

/* FAQ accordion */
.faq-list {
  margin-top: 16px;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 10px;
  overflow: hidden;
}

.faq-q {
  background: none;
  border: none;
  width: 100%;
  text-align: left;
  padding: 15px 18px;
  font-family: var(--font);
  font-size: 0.97rem;
  font-weight: 600;
  cursor: pointer;
  color: var(--text);
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 44px;
  gap: 12px;
  line-height: 1.4;
}

.faq-q:hover { background: var(--bg-alt); }

.faq-chevron {
  font-size: 0.75rem;
  color: var(--text-light);
  flex-shrink: 0;
  transition: transform 0.2s;
}

.faq-q.open .faq-chevron { transform: rotate(180deg); }

.faq-a {
  display: none;
  padding: 0 18px;
  font-size: 0.93rem;
  line-height: 1.75;
  color: var(--text-muted);
}

.faq-a.open {
  display: block;
  padding: 2px 18px 16px;
}

/* =========================================
   Related Calculators Section
   ========================================= */

.related-calcs {
  margin: 48px 0 32px;
  padding: 32px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.related-calcs-header {
  margin-bottom: 20px;
}

.related-calcs-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 4px;
  border: none;
  padding: 0;
}

.related-calcs-sub {
  font-size: 0.9rem;
  color: var(--text-light);
  margin: 0;
}

.related-calcs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 12px;
}

.related-calc-card {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 16px;
  background: var(--bg);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s;
}

.related-calc-card:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.12);
  text-decoration: none;
  color: var(--text);
}

.rc-icon {
  font-size: 1.4rem;
  flex-shrink: 0;
  line-height: 1;
  margin-top: 2px;
}

.rc-body {
  flex: 1;
  min-width: 0;
}

.rc-name {
  font-size: 0.93rem;
  font-weight: 600;
  color: var(--accent);
  line-height: 1.3;
  margin-bottom: 2px;
}

.related-calc-card:hover .rc-name {
  color: var(--accent-hover);
}

.rc-desc {
  font-size: 0.8rem;
  color: var(--text-light);
  line-height: 1.4;
}

@media (max-width: 480px) {
  .related-calcs {
    padding: 20px 16px;
  }
  .related-calcs-grid {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   CONCRETE CALCULATOR: SHAPE TABS
   ============================================ */
.shape-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: 14px;
}
.shape-tab {
  padding: 7px 14px;
  border: 1.5px solid var(--border);
  border-radius: 6px;
  background: #fff;
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  white-space: nowrap;
}
.shape-tab:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.shape-tab.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  font-weight: 600;
}

/* ============================================
   SHAPE DIAGRAM
   ============================================ */
.shape-diagram-wrap {
  margin: 10px 0 14px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  background: #f8faff;
  overflow: hidden;
}
.shape-diagram {
  padding: 8px 0 4px;
  max-width: 280px;
  margin: 0 auto;
}
.shape-diagram svg {
  width: 100%;
  height: auto;
  display: block;
}

/* ============================================
   TAB PANELS
   ============================================ */
.tab-panel {
  display: none;
}
.tab-panel.active-panel {
  display: block;
}
.calc-tip {
  font-size: 0.82rem;
  color: var(--text-light);
  margin: 6px 0 10px;
  font-style: italic;
}
.calc-select {
  width: 100%;
  padding: 10px 12px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  color: var(--text);
  background: #fff;
  cursor: pointer;
  appearance: auto;
}
.calc-select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

/* ============================================
   REBAR / REINFORCEMENT ESTIMATOR
   ============================================ */
.rebar-section {
  border-top: 1.5px solid var(--border);
  margin-top: 16px;
  padding-top: 0;
}
.rebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0 8px;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent);
  user-select: none;
}
.rebar-header:hover {
  color: var(--accent-hover);
}
.rebar-header em {
  font-weight: 400;
  color: var(--text-muted);
  font-style: italic;
}
.rebar-chevron {
  font-size: 0.8rem;
  transition: transform 0.2s;
}
.rebar-body {
  padding-bottom: 12px;
}
.rebar-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 12px;
}
.rebar-results {
  background: #f0f9f0;
  border: 1.5px solid #a7f3d0;
  border-radius: 8px;
  padding: 12px;
  margin-bottom: 10px;
}
.rebar-result-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}
.rebar-stat {
  text-align: center;
  padding: 8px;
  background: #fff;
  border-radius: 6px;
  border: 1px solid #d1fae5;
}
.rebar-val {
  font-size: 1.3rem;
  font-weight: 700;
  color: #059669;
  line-height: 1.2;
}
.rebar-lbl {
  font-size: 0.77rem;
  color: var(--text-muted);
  margin-top: 2px;
}
.rebar-tip {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-style: italic;
  margin-top: 8px;
}
.rebar-fiber-note {
  font-size: 0.9rem;
  color: var(--text);
  margin: 0;
}

/* ============================================
   READY-MIX vs BAGS
   ============================================ */
.readymix-section {
  border-top: 1.5px solid var(--border);
  margin-top: 16px;
  padding-top: 14px;
}
.readymix-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin: 0 0 10px;
}
.readymix-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  margin-bottom: 12px;
}
.readymix-table th {
  background: var(--accent);
  color: #fff;
  padding: 8px 10px;
  text-align: left;
  font-weight: 600;
  white-space: nowrap;
}
.readymix-table td {
  padding: 7px 10px;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  vertical-align: top;
}
.readymix-table tr:last-child td {
  border-bottom: none;
}
.readymix-table tr:nth-child(even) td {
  background: #f8f9fa;
}
.rm-recommendation {
  padding: 12px 16px;
  border-radius: 8px;
  font-size: 0.92rem;
  line-height: 1.5;
  background: #f8f9fa;
  border: 1.5px solid var(--border);
  color: var(--text-muted);
}
.rm-recommendation.rec-bags {
  background: #f0fdf4;
  border-color: #86efac;
  color: #166534;
}
.rm-recommendation.rec-mixed {
  background: #fffbeb;
  border-color: #fcd34d;
  color: #92400e;
}
.rm-recommendation.rec-readymix {
  background: #eff6ff;
  border-color: #93c5fd;
  color: #1e40af;
}
.rm-recommendation.rec-urgent {
  background: #fef2f2;
  border-color: #fca5a5;
  color: #991b1b;
}

/* ============================================
   COPY / PRINT ACTION BUTTONS
   ============================================ */
.action-buttons {
  display: flex;
  gap: 10px;
  margin-top: 16px;
  flex-wrap: wrap;
}
.action-btn {
  flex: 1;
  min-width: 140px;
  padding: 10px 16px;
  border: none;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s;
  text-align: center;
}
.action-btn:hover {
  background: var(--accent-hover);
}
.action-btn-outline {
  background: #fff;
  border: 2px solid var(--accent);
  color: var(--accent);
}
.action-btn-outline:hover {
  background: #eff6ff;
}
.copy-confirm {
  margin-top: 8px;
  font-size: 0.88rem;
  color: #059669;
  font-weight: 600;
  text-align: center;
}

/* ============================================
   PRINT STYLES
   ============================================ */
@media print {
  nav, header, footer,
  .breadcrumb, .related-calcs, .mt-3,
  .unit-toggle, #btn-calculate,
  .shape-tabs, .action-buttons,
  .seo-content, .shape-diagram-wrap,
  .calc-tip, .btn-calculate, .btn-clear, .calc-action-row {
    display: none !important;
  }
  .calc-tool {
    border: none;
    padding: 0;
    background: #fff;
  }
  .calc-results {
    border: 1px solid #ccc;
    page-break-inside: avoid;
  }
  body {
    font-size: 12pt;
  }
  .vol-item, .bag-item {
    break-inside: avoid;
  }
  .readymix-table {
    font-size: 10pt;
  }
}

/* ============================================
   RESPONSIVE: TABS + REBAR
   ============================================ */
@media (max-width: 600px) {
  .shape-tabs {
    gap: 3px;
  }
  .shape-tab {
    padding: 6px 10px;
    font-size: 0.8rem;
  }
  .rebar-inputs {
    grid-template-columns: 1fr;
  }
  .rebar-result-grid {
    grid-template-columns: 1fr 1fr;
  }
  .readymix-table th,
  .readymix-table td {
    padding: 6px 7px;
    font-size: 0.8rem;
  }
  .action-btn {
    font-size: 0.85rem;
    padding: 9px 12px;
  }
}