:root {
  --bg: #f7f7f7;
  --panel: #ffffff;
  --border: #d7d7d7;
  --primary: #1d4ed8;
  --accent: #f97316;
  --text: #111827;
  --muted: #6b7280;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Apple SD Gothic Neo', 'Segoe UI', sans-serif;
  color: var(--text);
  background: var(--bg);
}

button, input, select {
  font: inherit;
}

.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.top-panel {
  position: sticky;
  top: 0;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  padding: 16px;
  box-shadow: 0 2px 10px rgba(15, 23, 42, 0.05);
  z-index: 10;
}

.month-picker {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
}

.month-picker button {
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
}

.month-picker span {
  font-size: 1.1rem;
  font-weight: 700;
}

.settings-button {
  margin-bottom: 16px;
  border: none;
  background: var(--primary);
  color: #fff;
  padding: 10px 14px;
  border-radius: 10px;
  cursor: pointer;
}

.summary-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 12px;
}

.summary-item {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 12px;
}

.summary-item strong {
  display: block;
  margin-bottom: 6px;
}

.mileage-row {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 12px;
  align-items: end;
  margin-bottom: 8px;
}

.mileage-row label {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
}

.mileage-row input {
  width: 100%;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
}

.mileage-row button {
  border: none;
  background: var(--accent);
  color: #fff;
  padding: 12px 18px;
  border-radius: 12px;
  cursor: pointer;
}

.mileage-status {
  display: flex;
  gap: 16px;
  color: var(--muted);
}

.content-panel {
  display: grid;
  gap: 16px;
  padding: 16px;
}

.input-panel, .history-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 16px;
}

.tab-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
}

.tab {
  flex: 1;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: #fff;
  padding: 12px;
  cursor: pointer;
}

.tab.active {
  border-color: var(--primary);
  background: rgba(59, 130, 246, 0.12);
  color: var(--primary);
}

.form-section {
  display: grid;
  gap: 14px;
}

.field-group {
  display: grid;
  gap: 6px;
}

.field-group label {
  color: var(--muted);
}

.field-group input,
.field-group select {
  width: 100%;
  padding: 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
}

.primary-button {
  border: none;
  background: var(--primary);
  color: #fff;
  padding: 14px;
  border-radius: 14px;
  cursor: pointer;
}

.hidden {
  display: none !important;
}

.history-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.history-list {
  display: grid;
  gap: 12px;
}

.history-item {
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px;
  display: grid;
  gap: 8px;
  background: #fff;
}

.history-item .row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.history-item button {
  border: none;
  background: #ef4444;
  color: #fff;
  padding: 8px 12px;
  border-radius: 10px;
  cursor: pointer;
}

.settings-drawer {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.55);
  padding: 40px 16px;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 50;
}

.settings-drawer > div {
  width: min(560px, 100%);
  background: var(--panel);
  border-radius: 20px;
  padding: 24px;
  box-shadow: 0 20px 60px rgba(15, 23, 42, 0.18);
}

.drawer-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
}

.drawer-header button {
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: 1rem;
  cursor: pointer;
}

.route-add-row {
  display: flex;
  gap: 10px;
}

.route-add-row input {
  flex: 1;
}

.route-list {
  display: grid;
  gap: 10px;
  margin-top: 16px;
}

.route-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 14px;
}

.route-card button {
  background: #ef4444;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  transform: translateX(-50%);
  background: rgba(17, 24, 39, 0.95);
  color: #fff;
  padding: 12px 18px;
  border-radius: 999px;
  opacity: 0;
  transition: opacity 0.2s ease;
}

.toast.visible {
  opacity: 1;
}

@media (max-width: 780px) {
  .mileage-row {
    grid-template-columns: 1fr;
  }
  .summary-row {
    grid-template-columns: 1fr;
  }
}