:root {
  --bg-primary: #0d0d0d;
  --bg-secondary: #1a1a1a;
  --bg-tertiary: #252525;
  --bg-input: #2a2a2a;
  --border: #333;
  --border-focus: #666;
  --text-primary: #f0f0f0;
  --text-secondary: #999;
  --text-muted: #666;
  --accent: #00c2ff;
  --accent-dim: rgba(0, 194, 255, 0.1);
  --danger: #ff4444;
  --warning: #ffaa00;
  --success: #44cc66;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

.calculator-content {
  padding: 2rem 0;
}

/* Header overrides removed — uses shared site-header from main styles.css */

.page-title {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.description {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 2rem;
  max-width: 680px;
  line-height: 1.7;
}

/* Inputs Section */
.inputs-section {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.inputs-section h2 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.8rem;
}

.input-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem 1rem;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.input-group label {
  font-size: 0.78rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 500;
}

.input-group select,
.input-group input {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.6rem 0.75rem;
  color: var(--text-primary);
  font-size: 0.9rem;
  font-family: inherit;
  transition: border-color 0.15s;
}

.input-group select:focus,
.input-group input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent-dim);
}

.input-group select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23999' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2rem;
}

.input-group input[type="number"] {
  -moz-appearance: textfield;
}

.input-group input[type="number"]::-webkit-inner-spin-button,
.input-group input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
}

.input-group .hint {
  font-size: 0.72rem;
  color: var(--text-muted);
  min-height: 1.2em;
  line-height: 1.2;
}

.input-group .hint.warning {
  color: var(--warning);
}

/* Unit Toggle */
.results-section__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.results-section__header h2 {
  margin-bottom: 0;
}

.unit-toggle {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.unit-btn {
  background: var(--bg-input);
  border: none;
  color: var(--text-secondary);
  padding: 0.35rem 0.85rem;
  font-size: 0.8rem;
  font-family: inherit;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  border-right: 1px solid var(--border);
}

.unit-btn:last-child {
  border-right: none;
}

.unit-btn:hover {
  color: var(--text-primary);
}

.unit-btn.active {
  background: var(--accent);
  color: #000;
}

/* Results Section */
.results-section {
  margin-bottom: 1.5rem;
}

.results-section h2 {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0.75rem;
}

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

.section-note {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1rem;
}

.section-note strong {
  color: var(--text-primary);
}

/* Network group */
.network-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  align-items: start;
}

.interface-comparison {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
}

.interface-heading {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
  margin-bottom: 0.6rem;
}

.result-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
  transition: border-color 0.2s;
}

.result-card:hover {
  border-color: var(--border-focus);
}

.result-card .label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
}

.result-card .value {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.result-card .unit {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--text-secondary);
  margin-left: 0.25rem;
}

.result-card .detail {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.3rem;
}

.result-card.highlight {
  border-color: var(--accent);
  background: linear-gradient(135deg, var(--bg-secondary), var(--accent-dim));
}

.iface-row {
  margin-bottom: 0.85rem;
}

.iface-row:last-child {
  margin-bottom: 0;
}

.iface-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 0.3rem;
}

.iface-name {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-primary);
}

.iface-verdict {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.iface-ok .iface-verdict {
  color: var(--success);
}

.iface-over .iface-verdict {
  color: var(--danger);
}

.iface-bar-track {
  position: relative;
  height: 6px;
  background: var(--bg-tertiary);
  border-radius: 3px;
  overflow: visible;
}

.iface-bar-capacity {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  background: var(--border);
  border-radius: 3px;
}

.iface-bar-usage {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  border-radius: 3px;
  transition: width 0.3s ease;
}

.iface-ok .iface-bar-usage {
  background: var(--success);
  opacity: 0.7;
}

.iface-over .iface-bar-usage {
  background: var(--danger);
  opacity: 0.7;
}

.iface-bar-capacity-marker {
  position: absolute;
  top: -2px;
  width: 2px;
  height: calc(100% + 4px);
  background: var(--text-primary);
  border-radius: 1px;
}

.iface-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.68rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

/* Footer */
footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: center;
}

/* Responsive */
@media (max-width: 600px) {
  .container {
    padding: 1.25rem 1rem;
  }

  header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }

  .input-grid {
    grid-template-columns: 1fr 1fr;
  }

  .results-grid,
  .results-grid-4 {
    grid-template-columns: 1fr 1fr;
  }

  .network-group {
    grid-template-columns: 1fr;
  }

  .result-card .value {
    font-size: 1.3rem;
  }
}