:root {
  --primary: #ea5b0c;
  --primary-dark: #c74900;
  --primary-light: #fff3eb;
  --dark: #1a2332;
  --text: #2c3e50;
  --muted: #6b7a8f;
  --border: #e4e8ef;
  --bg: #f5f7fa;
  --panel: #ffffff;
  --success: #16a34a;
  --shadow: 0 2px 8px rgba(26, 35, 50, 0.06);
  --shadow-lg: 0 8px 28px rgba(26, 35, 50, 0.10);
  --radius: 10px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: 'Segoe UI', 'Sarabun', 'Prompt', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 15px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* HEADER */
.site-header {
  background: white;
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 20px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 14px;
}
.brand-logo {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  font-weight: 800;
  font-size: 20px;
  width: 46px;
  height: 46px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  letter-spacing: -1px;
}
.brand h1 {
  font-size: 18px;
  color: var(--dark);
  font-weight: 700;
}
.tagline {
  font-size: 12px;
  color: var(--muted);
  margin: 0;
}
.site-header nav {
  display: flex;
  gap: 24px;
}
.site-header nav a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  font-size: 14px;
  transition: color 0.15s;
}
.site-header nav a:hover { color: var(--primary); }
.nav-btn {
  background: var(--primary-light);
  color: var(--primary-dark);
  border: 1px solid #ffd9bf;
  border-radius: 6px;
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.15s;
}
.nav-btn:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}
.nav-btn:active {
  transform: scale(0.97);
}

/* HERO */
.hero {
  text-align: center;
  padding: 40px 0 32px;
}
.hero h2 {
  font-size: 28px;
  color: var(--dark);
  margin-bottom: 8px;
  font-weight: 700;
}
.hero p { color: var(--muted); }

/* GRID */
.grid {
  display: grid;
  grid-template-columns: 1fr 400px;
  gap: 24px;
  align-items: start;
}
@media (max-width: 960px) {
  .grid { grid-template-columns: 1fr; }
}

/* PANEL */
.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
}
.section-title {
  font-size: 16px;
  color: var(--dark);
  font-weight: 700;
  margin: 20px 0 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--primary-light);
}
.section-title:first-child { margin-top: 0; }

/* DROP ZONE */
.drop-zone {
  border: 2px dashed #c9d3e0;
  border-radius: var(--radius);
  padding: 40px 20px;
  text-align: center;
  background: #fafbfd;
  transition: all 0.2s;
  cursor: pointer;
}
.drop-zone:hover,
.drop-zone.dragover {
  border-color: var(--primary);
  background: var(--primary-light);
}
.drop-icon {
  font-size: 44px;
  color: var(--primary);
  margin-bottom: 8px;
}
.drop-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--dark);
  margin-bottom: 4px;
}
.drop-sub {
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 16px;
}

/* FILE INFO */
.file-info {
  margin-top: 16px;
  background: var(--primary-light);
  border: 1px solid #ffd9bf;
  border-radius: var(--radius);
  padding: 16px;
}
.thumbnail-wrap {
  background: white;
  border: 1px solid #ffd9bf;
  border-radius: 8px;
  padding: 8px;
  margin-bottom: 12px;
  text-align: center;
}
#thumbnail {
  display: block;
  margin: 0 auto;
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}
.file-info.hidden { display: none; }
.bd-row.hidden { display: none; }
.file-row {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  font-size: 14px;
  border-bottom: 1px dashed #ffd0af;
}
.file-row:last-of-type { border: 0; }
.file-row.highlight { font-size: 16px; padding-top: 10px; }
.file-row.highlight strong { color: var(--primary-dark); font-size: 18px; }

/* FORM */
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.field.full { grid-column: 1 / -1; }
.field span {
  font-size: 13px;
  color: var(--muted);
  font-weight: 500;
}
.field input,
.field select {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  background: white;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.field input:focus,
.field select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(234, 91, 12, 0.12);
}

.range-wrap {
  display: flex;
  gap: 12px;
  align-items: center;
}
.range-wrap input[type="range"] { flex: 1; accent-color: var(--primary); }
.range-val {
  min-width: 52px;
  text-align: right;
  font-weight: 600;
  color: var(--primary-dark);
}

.price-combo {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
  padding: 10px 12px;
  background: #fafbfd;
  border: 1px solid var(--border);
  border-radius: 8px;
}
.price-combo input {
  flex: 1;
  min-width: 80px;
  max-width: 130px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  font-family: inherit;
  background: white;
}
.price-combo input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(234, 91, 12, 0.12);
}
.combo-icon {
  font-size: 18px;
}
.combo-op {
  color: var(--muted);
  font-size: 13px;
  font-weight: 500;
  white-space: nowrap;
}
.combo-eq {
  color: var(--primary);
  font-weight: 700;
  font-size: 15px;
  padding: 0 2px;
}

.scale-inputs {
  display: flex;
  gap: 8px;
  align-items: center;
}
.scale-inputs input {
  flex: 1;
  min-width: 0;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  background: white;
}
.scale-inputs input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(234, 91, 12, 0.12);
}
.scale-inputs input:disabled {
  background: #f5f7fa;
  color: var(--muted);
  cursor: not-allowed;
}
.scale-x {
  color: var(--muted);
  font-weight: 600;
}

.checkbox-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  padding: 8px 0;
}
.checkbox-row label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  cursor: pointer;
}

/* QUOTE */
.quote-panel {
  position: sticky;
  top: 100px;
}
.quote-summary {
  background: #f8fafc;
  border-radius: 8px;
  padding: 14px;
  margin-bottom: 16px;
}
.summary-row {
  display: flex;
  justify-content: space-between;
  padding: 4px 0;
  font-size: 14px;
}
.summary-row strong { color: var(--dark); }
.summary-detail { padding-top: 0 !important; }
.weight-detail {
  font-size: 11px;
  color: var(--muted);
  font-style: italic;
  text-align: right;
}

.bd-row.min-charge span { color: var(--primary) !important; font-weight: 600; }

.breakdown {
  border-top: 1px solid var(--border);
  padding-top: 14px;
  margin-bottom: 14px;
}
.bd-row {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  font-size: 14px;
}
.bd-row span:first-child { color: var(--muted); }
.bd-row.subtotal {
  border-top: 1px dashed var(--border);
  padding-top: 10px;
  margin-top: 6px;
  font-weight: 600;
}
.bd-row.subtotal span { color: var(--text) !important; }

.grand-total {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  padding: 16px;
  border-radius: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}
.grand-total span { font-size: 14px; opacity: 0.9; }
.grand-total strong { font-size: 24px; font-weight: 700; }

/* BUTTONS */
.btn {
  border: none;
  border-radius: 8px;
  padding: 11px 20px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
  font-family: inherit;
}
.btn.small { padding: 6px 12px; font-size: 13px; }
.btn.full-width { width: 100%; display: block; margin-bottom: 8px; }
.btn-primary {
  background: var(--primary);
  color: white;
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}
.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-ghost:hover { background: #f8fafc; border-color: var(--primary); color: var(--primary); }

.disclaimer {
  font-size: 11px;
  color: var(--muted);
  text-align: center;
  margin-top: 12px;
}

/* MATERIALS */
.materials-section { margin: 48px 0 32px; }
.materials-section h2,
.about h2 {
  font-size: 22px;
  color: var(--dark);
  margin-bottom: 18px;
  font-weight: 700;
}
.material-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 14px;
}
.mat-card {
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  transition: transform 0.15s, box-shadow 0.15s;
}
.mat-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}
.mat-card h4 {
  color: var(--dark);
  margin-bottom: 4px;
  font-size: 16px;
}
.mat-card .mat-price {
  color: var(--primary);
  font-weight: 700;
  font-size: 18px;
  margin: 8px 0;
}
.mat-card .mat-desc { font-size: 12px; color: var(--muted); }

/* ABOUT */
.about { margin: 32px 0 48px; background: white; padding: 28px; border-radius: var(--radius); border: 1px solid var(--border); }
.about ol { padding-left: 22px; }
.about li { padding: 6px 0; color: var(--text); }
.about strong { color: var(--primary-dark); }

/* COMPANY DETAILS (collapsible) */
.company-details {
  margin-top: 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fafbfd;
  padding: 12px 14px;
}
.company-details summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  color: var(--dark);
  user-select: none;
  padding: 2px 0;
  list-style: none;
}
.company-details summary::-webkit-details-marker { display: none; }
.company-details summary::before {
  content: "▸";
  display: inline-block;
  width: 14px;
  color: var(--primary);
  transition: transform 0.15s;
}
.company-details[open] summary::before { transform: rotate(90deg); }
.company-details summary:hover { color: var(--primary); }

.subsection-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--dark);
  margin: 18px 0 10px;
  padding-top: 12px;
  border-top: 1px dashed var(--border);
}

/* TOAST */
.toast {
  position: fixed;
  top: 20px;
  right: 20px;
  background: #1a2332;
  color: white;
  padding: 12px 18px;
  border-radius: 8px;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.25);
  z-index: 9999;
  font-size: 14px;
  font-weight: 500;
  max-width: 360px;
  opacity: 0;
  transform: translateY(-8px);
  transition: opacity 0.25s, transform 0.25s;
  pointer-events: none;
}
.toast.show { opacity: 1; transform: translateY(0); }
.toast.toast-success { background: #16a34a; }
.toast.toast-error { background: #dc2626; }
.toast.toast-warning { background: #d97706; }

/* FOOTER */
.site-footer {
  background: var(--dark);
  color: white;
  padding: 22px 0;
  text-align: center;
  margin-top: 40px;
  font-size: 13px;
  opacity: 0.9;
}