:root {
  --bg: #f4f6f8;
  --surface: #ffffff;
  --border: #e2e5e9;
  --text: #1c2226;
  --text-muted: #667085;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --danger: #dc2626;
  --danger-bg: #fef2f2;
  --success: #16a34a;
  --warn: #b45309;
  --warn-bg: #fffbeb;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.06), 0 1px 3px rgba(16, 24, 40, 0.1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1417;
    --surface: #171d21;
    --border: #2a3238;
    --text: #e7edf0;
    --text-muted: #9aa7ae;
    --primary: #3b82f6;
    --primary-hover: #60a5fa;
    --danger: #f87171;
    --danger-bg: #2a1414;
    --success: #4ade80;
    --warn: #fbbf24;
    --warn-bg: #2a2110;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 1px 3px rgba(0, 0, 0, 0.4);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

a {
  color: var(--primary);
}

.page {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 20px 60px;
}

.centered-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

nav.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

nav.topbar .brand {
  font-weight: 700;
  font-size: 1.05rem;
}

nav.topbar .links {
  display: flex;
  gap: 6px;
  align-items: center;
}

nav.topbar .links a,
nav.topbar .links button {
  padding: 6px 12px;
  border-radius: 6px;
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.92rem;
  border: none;
  background: transparent;
  cursor: pointer;
  font-family: inherit;
}

nav.topbar .links a.active,
nav.topbar .links a:hover,
nav.topbar .links button:hover {
  background: var(--bg);
  color: var(--text);
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  margin-bottom: 20px;
}

.card h2 {
  margin-top: 0;
  font-size: 1rem;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.card.auth {
  width: 100%;
  max-width: 380px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}

.stat {
  font-size: 1.9rem;
  font-weight: 700;
}

.stat small {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: none;
  margin-top: 4px;
}

label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 4px;
  margin-top: 12px;
}

input,
select {
  width: 100%;
  padding: 9px 10px;
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.95rem;
}

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

button {
  cursor: pointer;
  font-family: inherit;
}

button.primary {
  background: var(--primary);
  color: white;
  border: none;
  padding: 10px 16px;
  border-radius: 7px;
  font-size: 0.95rem;
  font-weight: 600;
}

button.primary:hover {
  background: var(--primary-hover);
}

button.primary:disabled {
  opacity: 0.6;
  cursor: default;
}

button.ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 5px 10px;
  border-radius: 6px;
  font-size: 0.82rem;
}

button.ghost:hover {
  background: var(--bg);
}

button.danger-ghost {
  composes: ghost;
}

form .row {
  display: flex;
  gap: 12px;
}

form .row > * {
  flex: 1;
}

form .submit-row {
  margin-top: 18px;
}

.message {
  margin-top: 12px;
  padding: 9px 12px;
  border-radius: 7px;
  font-size: 0.88rem;
}

.message.error {
  background: var(--danger-bg);
  color: var(--danger);
}

.message.success {
  background: var(--warn-bg);
  color: var(--success);
}

.message:empty {
  display: none;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

th,
td {
  text-align: left;
  padding: 9px 8px;
  border-bottom: 1px solid var(--border);
}

th {
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

tbody tr:hover {
  background: var(--bg);
}

.badge {
  display: inline-block;
  padding: 2px 7px;
  border-radius: 100px;
  font-size: 0.72rem;
  font-weight: 600;
}

.badge.estimated {
  background: var(--warn-bg);
  color: var(--warn);
}

.badge.measured {
  background: rgba(22, 163, 74, 0.12);
  color: var(--success);
}

.badge.anomalous,
.badge.rolled-over {
  background: var(--danger-bg);
  color: var(--danger);
}

.table-actions {
  display: flex;
  gap: 6px;
}

.empty-hint {
  color: var(--text-muted);
  font-size: 0.9rem;
  padding: 12px 0;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 50;
}

.modal-backdrop[hidden] {
  display: none;
}

.modal {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 20px;
  width: 100%;
  max-width: 360px;
  box-shadow: var(--shadow);
}

.modal h3 {
  margin-top: 0;
}

.modal .actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 18px;
}

canvas#usageChart {
  width: 100%;
  height: 220px;
  display: block;
}

.helper-text {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
}

.setup-settings-block {
  margin-top: 8px;
  padding-top: 14px;
  border-top: 1px dashed var(--border);
}