:root {
  --bg: #f4f6f8;
  --panel: #ffffff;
  --border: #dfe3e8;
  --text: #1c2530;
  --text-muted: #5b6b7a;
  --accent: #2563eb;
  --accent-dark: #1d4ed8;
  --danger: #b3261e;
  --danger-bg: #fdecea;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
}

.app-header {
  padding: 18px 28px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}

.app-header h1 {
  margin: 0;
  font-size: 20px;
  font-weight: 600;
}

.app-header p {
  margin: 4px 0 0;
  color: var(--text-muted);
  font-size: 13px;
}

.app-body {
  max-width: 1100px;
  margin: 0 auto;
  padding: 20px 24px 40px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px 22px;
}

.panel h2 {
  margin: 0 0 16px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 16px;
  align-items: end;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.field-with-btn {
  display: flex;
  gap: 8px;
}

select, input[type="number"] {
  width: 100%;
  padding: 9px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  background: #fff;
  color: var(--text);
}

select:focus, input:focus {
  outline: 2px solid var(--accent);
  outline-offset: -1px;
}

.pick-btn {
  border: 1px solid var(--border);
  background: #f7f9fb;
  border-radius: 6px;
  padding: 0 10px;
  cursor: pointer;
  font-size: 14px;
  white-space: nowrap;
}

.pick-btn.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.custom-label {
  font-size: 12px;
  color: var(--accent-dark);
  min-height: 16px;
}

.checkbox-field {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text);
}

.checkbox-field input { width: 16px; height: 16px; }

.options-row {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-top: 16px;
  flex-wrap: wrap;
}

.calc-btn {
  padding: 10px 22px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.calc-btn:hover { background: var(--accent-dark); }

.pick-hint {
  margin-top: 10px;
  font-size: 12px;
  color: var(--accent-dark);
  background: #eaf1ff;
  padding: 8px 10px;
  border-radius: 6px;
}

.error-msg {
  margin-top: 12px;
  font-size: 13px;
  color: var(--danger);
  background: var(--danger-bg);
  padding: 8px 10px;
  border-radius: 6px;
}

#map {
  height: 480px;
  width: 100%;
  border-radius: 8px;
  border: 1px solid var(--border);
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.result-card {
  background: #f7f9fb;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  text-align: center;
}

.result-card .value {
  font-size: 26px;
  font-weight: 700;
  color: var(--accent-dark);
}

.result-card .unit {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 2px;
}

.result-card .label {
  font-size: 12px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 6px;
}

#routeSummary {
  margin: 14px 0 0;
  font-size: 13px;
  color: var(--text-muted);
  text-align: center;
}

@media (max-width: 720px) {
  .input-grid { grid-template-columns: 1fr; }
  .results-grid { grid-template-columns: 1fr; }
}