/* Dingjian New Materials - B2B Industrial Design Tokens & Core Engine */
:root {
  --primary: #0f172a;
  --primary-light: #1e293b;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-orange: #ea580c;
  --accent-emerald: #059669;
  --surface: #ffffff;
  --surface-alt: #f8fafc;
  --surface-card: #ffffff;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: var(--font-sans);
  color: var(--text-main);
  background-color: var(--surface-alt);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header & Navigation */
header.site-header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 1000;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}
.brand-badge {
  background: var(--primary);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  letter-spacing: 0.05em;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}
.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s;
}
.nav-links a:hover, .nav-links a.active {
  color: var(--accent);
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s ease;
}
.btn-primary {
  background: var(--accent);
  color: #ffffff;
}
.btn-primary:hover {
  background: var(--accent-hover);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}
.btn-dark {
  background: var(--primary);
  color: #ffffff;
}
.btn-dark:hover {
  background: var(--primary-light);
}
.btn-outline {
  background: transparent;
  border-color: var(--border-strong);
  color: var(--text-main);
}
.btn-outline:hover {
  background: #f1f5f9;
}
.btn-sm {
  font-size: 0.85rem;
  padding: 0.4rem 0.85rem;
}

/* Hero Section */
.hero-section {
  background: linear-gradient(135deg, #0b1329 0%, #1e293b 100%);
  color: #ffffff;
  padding: 4.5rem 0 4rem;
  position: relative;
  overflow: hidden;
}
.hero-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(37, 99, 235, 0.2);
  border: 1px solid rgba(37, 99, 235, 0.4);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  color: #93c5fd;
  margin-bottom: 1.5rem;
}
.hero-title {
  font-size: clamp(2rem, 4vw, 3.25rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
  max-width: 860px;
}
.hero-desc {
  font-size: 1.15rem;
  color: #94a3b8;
  max-width: 720px;
  margin-bottom: 2rem;
  line-height: 1.6;
}
.hero-stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.25rem;
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}
.hero-stat-card {
  background: rgba(255, 255, 255, 0.04);
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 255, 255, 0.08);
}
.stat-num {
  font-size: 1.85rem;
  font-weight: 800;
  color: #60a5fa;
  font-family: var(--font-mono);
}
.stat-label {
  font-size: 0.85rem;
  color: #cbd5e1;
  margin-top: 0.25rem;
}

/* Sections */
.section {
  padding: 5rem 0;
}
.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 3.5rem;
}
.section-tag {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--accent);
  letter-spacing: 0.08em;
  margin-bottom: 0.5rem;
}
.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1.2;
  margin-bottom: 1rem;
}
.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* Cards & Grids */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.card-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-sm);
  background: #eff6ff;
  color: var(--accent);
  margin-bottom: 1rem;
}
.card-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.75rem;
}
.card-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

/* Spec Table */
.spec-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  margin: 1rem 0;
}
.spec-table th, .spec-table td {
  padding: 0.6rem 0.75rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
}
.spec-table th {
  background: var(--surface-alt);
  color: var(--text-muted);
  font-weight: 600;
}
.spec-table td.highlight {
  font-weight: 700;
  color: var(--accent);
}

/* Interactive Workbench / Calculator */
.calc-box {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-md);
  margin-top: 2rem;
}
.calc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
}
.form-group {
  margin-bottom: 1.25rem;
}
.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.4rem;
}
.form-control {
  width: 100%;
  padding: 0.65rem 0.9rem;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  font-size: 0.95rem;
}
.calc-result-box {
  background: #f8fafc;
  border: 1px solid #cbd5e1;
  border-radius: var(--radius-md);
  padding: 1.5rem;
}
.result-row {
  display: flex;
  justify-content: space-between;
  padding: 0.5rem 0;
  border-bottom: 1px dashed var(--border);
  font-size: 0.95rem;
}
.result-row.total {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--accent-emerald);
  border-bottom: none;
  padding-top: 1rem;
}

/* Footer */
footer.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 4.5rem 0 2rem;
  font-size: 0.95rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3.5rem;
}
.footer-title {
  color: #ffffff;
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
}
.footer-links {
  list-style: none;
}
.footer-links li {
  margin-bottom: 0.6rem;
}
.footer-links a:hover {
  color: #ffffff;
}
.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid #1e293b;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

/* Floating WhatsApp / Sample CTA */
.floating-bar {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 999;
  display: flex;
  gap: 0.75rem;
}
.floating-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--accent-emerald);
  color: #ffffff;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.9rem;
  box-shadow: var(--shadow-lg);
  transition: transform 0.2s;
}
.floating-pill:hover {
  transform: scale(1.05);
}

@media (max-width: 900px) {
  .calc-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 2rem; }
  .nav-links { display: none; }
}