:root {
  --color-bg: #ffffff;
  --color-text: #111827;
  --color-muted: #6b7280;
  --color-card: #f8fafc;
  --color-border: #e5e7eb;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-danger: #dc2626;
  --color-danger-light: #fee2e2;
  --shadow: 0 16px 40px rgba(15, 23, 42, 0.08);
  --radius: 18px;
  --container: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

a { color: inherit; text-decoration: none; }

button, input, select { font: inherit; }

.container {
  width: min(100% - 32px, var(--container));
  margin: 0 auto;
}

.section { padding: 72px 0; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255,255,255,0.94);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(14px);
}

.header-inner {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-primary);
  white-space: nowrap;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  color: var(--color-muted);
  font-size: 0.95rem;
}

.main-nav a:hover { color: var(--color-primary); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 999px;
  padding: 12px 20px;
  font-weight: 700;
  cursor: pointer;
  transition: 0.2s ease;
}

.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-secondary { background: #eef2ff; color: var(--color-primary); }
.btn-secondary:hover { background: #dbeafe; }
.btn-danger { background: var(--color-danger-light); color: var(--color-danger); }
.btn-danger:hover { background: #fecaca; }

.hero {
  background:
    radial-gradient(circle at top right, rgba(37,99,235,0.14), transparent 35%),
    linear-gradient(180deg, #fff, #f8fafc);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 36px;
  align-items: center;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--color-primary);
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.78rem;
}

h1, h2, h3 { line-height: 1.15; margin: 0 0 16px; }
h1 { font-size: clamp(2.35rem, 6vw, 4.75rem); max-width: 820px; }
h2 { font-size: clamp(1.8rem, 4vw, 2.6rem); }
h3 { font-size: 1.2rem; }

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--color-muted);
  max-width: 680px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  margin-top: 28px;
  flex-wrap: wrap;
}

.hero-card {
  background: #fff;
  box-shadow: var(--shadow);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  display: grid;
  gap: 16px;
}

.hero-stat {
  background: var(--color-card);
  border-radius: 16px;
  padding: 22px;
  border: 1px solid var(--color-border);
}

.hero-stat strong {
  display: block;
  font-size: 2rem;
  color: var(--color-primary);
}

.hero-stat span { color: var(--color-muted); }

.section-heading {
  max-width: 760px;
  margin-bottom: 32px;
}

.section-heading p { color: var(--color-muted); }

.calculator-card,
.content-card,
.guide-card,
.contact-card,
.container-results {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.calculator-card { padding: 24px; }

.error-box {
  display: none;
  background: var(--color-danger-light);
  color: var(--color-danger);
  border-radius: 12px;
  padding: 14px 16px;
  margin-bottom: 18px;
  font-weight: 700;
}

.error-box.show { display: block; }

.carton-table-wrapper {
  width: 100%;
  overflow-x: auto;
}

.carton-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 850px;
}

.carton-table th,
.carton-table td {
  padding: 12px;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  vertical-align: middle;
}

.carton-table th {
  font-size: 0.86rem;
  color: var(--color-muted);
  background: var(--color-card);
}

.carton-table input,
.carton-table select {
  width: 100%;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 10px;
  outline: none;
  background: #fff;
}

.carton-table input:focus,
.carton-table select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.14);
}

.remove-btn {
  border: 0;
  background: var(--color-danger-light);
  color: var(--color-danger);
  border-radius: 10px;
  padding: 8px 12px;
  cursor: pointer;
  font-weight: 800;
}

.calculator-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 24px;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.result-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow);
}

.result-card span {
  display: block;
  color: var(--color-muted);
  font-size: 0.92rem;
}

.result-card strong {
  display: block;
  margin-top: 8px;
  color: var(--color-primary);
  font-size: 1.7rem;
}

.container-results {
  margin-top: 28px;
  padding: 24px;
}

.container-utilization-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.utilization-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 18px;
}

.progress-track {
  height: 12px;
  background: #e5e7eb;
  border-radius: 999px;
  overflow: hidden;
  margin: 12px 0;
}

.progress-bar {
  height: 100%;
  width: 0;
  background: var(--color-primary);
  border-radius: inherit;
}

.content-grid, .guide-grid, .tools-grid {
  display: grid;
  gap: 18px;
}

.content-grid { grid-template-columns: repeat(2, 1fr); }
.content-card { padding: 24px; }
.content-card p { color: var(--color-muted); }
.full-width { grid-column: 1 / -1; }

.guide-grid { grid-template-columns: repeat(3, 1fr); }
.guide-card { padding: 24px; }
.guide-card p {
  color: var(--color-primary);
  font-size: 1.6rem;
  margin: 0 0 8px;
}
.guide-card span { color: var(--color-muted); }

.faq-list { display: grid; gap: 14px; }

details {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 18px 20px;
  box-shadow: 0 8px 24px rgba(15,23,42,0.04);
}

summary {
  cursor: pointer;
  font-weight: 800;
}

details p {
  color: var(--color-muted);
  margin-bottom: 0;
}

.tools-grid { grid-template-columns: repeat(5, 1fr); }

.tool-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 20px;
  color: var(--color-text);
  font-weight: 800;
  box-shadow: 0 8px 24px rgba(15,23,42,0.05);
}

.tool-card:hover {
  color: var(--color-primary);
  transform: translateY(-2px);
}

.contact-card {
  text-align: center;
  padding: 42px 24px;
  max-width: 760px;
  margin: 0 auto;
}

.contact-card p { color: var(--color-muted); }

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 28px 0;
  background: var(--color-card);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  flex-wrap: wrap;
  color: var(--color-muted);
}

.footer-inner nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-inner a:hover { color: var(--color-primary); }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}


.volumetric-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.form-group {
  display: grid;
  gap: 8px;
}

.form-group label {
  font-weight: 800;
  color: var(--color-text);
}

.form-group input,
.form-group select {
  width: 100%;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 12px;
  outline: none;
  background: #fff;
}

.form-group input:focus,
.form-group select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.14);
}

.volumetric-results {
  margin-top: 28px;
}


.container-dimension-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
}

.container-dimension-card p {
  color: var(--color-muted);
  font-size: 1.05rem;
}

.dimension-table-wrapper {
  width: 100%;
  overflow-x: auto;
  margin-top: 22px;
}

.dimension-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 760px;
}

.dimension-table th,
.dimension-table td {
  border: 1px solid var(--color-border);
  padding: 16px;
  text-align: left;
}

.dimension-table th {
  background: var(--color-card);
  font-weight: 800;
}

.dimension-table td {
  color: var(--color-text);
}


.charge-note {
  margin-top: 18px;
  padding: 16px;
  border-radius: 14px;
  background: #eef2ff;
  color: var(--color-primary);
  font-weight: 800;
}

@media (max-width: 980px) {
  .main-nav, .header-cta { display: none; }
  .hero-grid, .content-grid, .guide-grid, .container-utilization-grid, .volumetric-grid { grid-template-columns: 1fr; }
  .results-grid { grid-template-columns: repeat(2, 1fr); }
  .tools-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 560px) {
  .section { padding: 52px 0; }
  .results-grid, .tools-grid { grid-template-columns: 1fr; }
  .calculator-card { padding: 16px; }
  .btn { width: 100%; }
  .calculator-actions, .hero-actions { flex-direction: column; }
}


.page-hero {
  background: linear-gradient(180deg, #ffffff, #f8fafc);
  padding: 72px 0 36px;
}

.page-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px;
}

.page-content {
  max-width: 920px;
}

.page-content h2 {
  margin-top: 34px;
  font-size: 1.65rem;
}

.page-content h3 {
  margin-top: 24px;
}

.page-content p,
.page-content li {
  color: var(--color-muted);
}

.page-content ul {
  padding-left: 22px;
}

.legal-date {
  color: var(--color-muted);
  font-weight: 700;
}



/* Blog and article styles */
.article-hero .article-meta,
.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  color: var(--color-muted);
  font-size: 0.95rem;
  margin-top: 14px;
}

.article-content {
  line-height: 1.75;
}

.article-content a,
.blog-card a {
  color: var(--color-primary);
  font-weight: 700;
  text-decoration: none;
}

.article-content a:hover,
.blog-card a:hover {
  text-decoration: underline;
}

.article-image {
  margin: 28px 0;
}

.article-image img {
  width: 100%;
  height: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.article-image figcaption {
  margin-top: 10px;
  color: var(--color-muted);
  font-size: 0.95rem;
}

.table-scroll {
  overflow-x: auto;
  margin: 18px 0;
}

.content-table {
  width: 100%;
  border-collapse: collapse;
}

.content-table th,
.content-table td {
  border: 1px solid var(--color-border);
  padding: 12px;
  text-align: left;
}

.content-table th {
  background: #f8fafc;
}

.faq-section {
  margin-top: 34px;
}

.author-box {
  margin-top: 36px;
  padding: 24px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: #f8fafc;
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.blog-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.blog-card .btn {
  margin-top: auto;
  align-self: flex-start;
}

@media (max-width: 900px) {
  .blog-grid { grid-template-columns: 1fr; }
}
.contact-email {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-primary);
  text-decoration: none;
}

.contact-email:hover {
  text-decoration: underline;
}
.site-notice {
  background: #fff8e1;
  color: #5c4300;
  border-bottom: 1px solid #f0d98a;
  padding: 12px 20px;
  text-align: center;
  font-size: 14px;
  line-height: 1.6;
  font-weight: 500;
}

.site-notice a {
  color: #000;
  font-weight: 700;
  text-decoration: underline;
}