:root {
  --color-bg: #f5f5f5;
  --color-surface: #ffffff;
  --color-border: #ddd;
  --color-text: #1a1a1a;
  --color-text-muted: #666;
  --color-primary: #3b82f6;
  --color-best-bg: #dcfce7;
  --color-best-border: #16a34a;
  --color-worst-bg: #fee2e2;
  --color-worst-border: #dc2626;
  --color-selected-bg: #eff6ff;
  --color-selected-border: #3b82f6;
  --color-warning-bg: #fef9c3;
  --color-warning-border: #ca8a04;
  --color-warning-text: #713f12;
  --color-error-bg: #fee2e2;
  --color-error-border: #dc2626;
  --color-error-text: #7f1d1d;
  --color-section-header: #f1f5f9;
  --radius: 6px;
  --shadow: 0 1px 3px rgba(0,0,0,0.1);
}

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

body {
  font-family: system-ui, -apple-system, sans-serif;
  font-size: 14px;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
}

/* Header */
header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 24px;
}

header h1 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
}

#rate-info {
  font-size: 12px;
  color: var(--color-text-muted);
}

/* Error banner */
.error-banner {
  background: var(--color-error-bg);
  border: 1px solid var(--color-error-border);
  color: var(--color-error-text);
  padding: 12px 24px;
  font-weight: 500;
}

/* Main layout */
main {
  display: grid;
  grid-template-columns: minmax(300px, 360px) 1fr;
  gap: 16px;
  padding: 16px;
  align-items: start;
}

@media (max-width: 768px) {
  main {
    grid-template-columns: 1fr;
  }
}

/* Input panel */
#inputs-panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
}

#inputs-panel h2 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--color-text);
}

fieldset {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 12px;
  margin-bottom: 10px;
}

fieldset:last-child {
  margin-bottom: 0;
}

legend {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
  padding: 0 4px;
}

label {
  display: flex;
  flex-direction: column;
  gap: 3px;
  font-size: 13px;
  color: var(--color-text);
  margin-bottom: 8px;
}

label:last-child {
  margin-bottom: 0;
}

input[type="number"] {
  padding: 5px 8px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 13px;
  width: 100%;
  background: var(--color-surface);
  color: var(--color-text);
}

input[type="number"]:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px rgba(59,130,246,0.2);
}

select {
  padding: 5px 8px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 13px;
  width: 100%;
  background: var(--color-surface);
  color: var(--color-text);
  cursor: pointer;
}

select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px rgba(59,130,246,0.2);
}

.fvf-custom-label {
  margin-top: 6px;
}

.weight-inputs {
  display: flex;
  align-items: center;
  gap: 5px;
}

.weight-lb {
  width: 58px;
}

.weight-oz {
  width: 64px;
}

.weight-unit {
  color: var(--color-text-muted);
  font-size: 12px;
  flex-shrink: 0;
}

#weight-split-section,
#weight-combined-section {
  margin-top: 8px;
}

.media-mail-notice {
  background: #fffbeb;
  border: 1px solid #f59e0b;
  border-left: 3px solid #d97706;
  border-radius: var(--radius);
  padding: 10px 12px;
  font-size: 12px;
  color: #78350f;
  margin-bottom: 10px;
}

.media-mail-notice strong {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
}

.media-mail-notice p {
  margin: 6px 0 2px;
}

.media-mail-notice ul {
  margin: 4px 0 0 16px;
  padding: 0;
}

.media-mail-notice li {
  margin-bottom: 2px;
}

.dimensions-row {
  display: flex;
  align-items: center;
  gap: 6px;
}

.dimensions-row label {
  flex: 1;
  margin-bottom: 0;
}

.dim-sep {
  color: var(--color-text-muted);
  font-size: 14px;
  flex-shrink: 0;
  margin-top: 14px;
}

.dim-info {
  font-size: 11px;
  color: var(--color-text-muted);
  margin-top: 6px;
  min-height: 16px;
}

.radio-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-top: 4px;
}

.radio-group label,
.checkbox-label {
  flex-direction: row;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  margin-bottom: 0;
}

.disabled-label {
  opacity: 0.45;
}

.coming-soon {
  font-size: 11px;
  color: var(--color-text-muted);
}

/* Results panel */
#results-panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
}

#results-panel h2 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--color-text);
}

/* Surcharge warnings */
.warning-banner {
  background: var(--color-warning-bg);
  border: 1px solid var(--color-warning-border);
  color: var(--color-warning-text);
  border-radius: var(--radius);
  padding: 8px 12px;
  font-size: 13px;
  margin-bottom: 8px;
}

/* Results table */
#results-table-wrapper {
  overflow-x: auto;
  margin-bottom: 20px;
}

#results-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

#results-table th {
  background: var(--color-section-header);
  font-weight: 600;
  padding: 8px 10px;
  text-align: left;
  border-bottom: 2px solid var(--color-border);
  white-space: nowrap;
}

#results-table td {
  padding: 8px 10px;
  border-bottom: 1px solid var(--color-border);
}

#results-table tbody tr {
  cursor: pointer;
  transition: background 0.1s;
}

#results-table tbody tr:hover {
  background: #f8fafc;
}

#results-table tbody tr:nth-child(even):not(.row-best):not(.row-worst):not(.row-selected) {
  background: #fafafa;
}

#results-table tbody tr:nth-child(even):hover {
  background: #f1f5f9;
}

.price-cell {
  font-weight: 600;
}

.row-best {
  background: var(--color-best-bg) !important;
  border-left: 3px solid var(--color-best-border);
}

.row-worst {
  background: var(--color-worst-bg) !important;
  border-left: 3px solid var(--color-worst-border);
}

.row-selected {
  background: var(--color-selected-bg) !important;
  border-left: 3px solid var(--color-selected-border);
  font-weight: 600;
}

.row-best.row-selected {
  border-left: 3px solid var(--color-selected-border);
}

.buyer-pays-note {
  font-size: 11px;
  color: var(--color-text-muted);
  font-style: italic;
  cursor: default !important;
}

/* Breakdown section */
#breakdown-section {
  border-top: 1px solid var(--color-border);
  padding-top: 16px;
}

.breakdown-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

.breakdown-table td {
  padding: 5px 8px;
  border-bottom: 1px solid #f0f0f0;
}

.breakdown-table td:last-child {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.breakdown-table .section-header td {
  background: var(--color-section-header);
  font-weight: 600;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
  padding: 6px 8px 4px;
  border-bottom: 1px solid var(--color-border);
}

.breakdown-table .subtotal td {
  font-weight: 600;
  border-top: 1px solid var(--color-border);
  border-bottom: 2px solid var(--color-border);
}

.breakdown-table .result-row td {
  font-weight: 700;
  font-size: 14px;
  color: var(--color-primary);
  border-bottom: none;
}

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

.dim-badge {
  display: inline-block;
  background: #dbeafe;
  color: #1e40af;
  font-size: 10px;
  font-weight: 700;
  padding: 1px 5px;
  border-radius: 3px;
  vertical-align: middle;
  margin-right: 2px;
}

/* Footer */
footer {
  padding: 10px 24px;
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
}

#rate-footer {
  font-size: 11px;
  color: var(--color-text-muted);
}