:root {
  color-scheme: light dark;

  --bg: #f4f6f8;
  --bg-elevated: #ffffff;
  --bg-inset: #f0f2f5;
  --text: #16191d;
  --text-muted: #6b7280;
  --border: #e3e6ea;
  --accent: #0d9488;
  --accent-strong: #0f766e;
  --accent-soft: #ccfbf1;
  --success: #0f9d58;
  --success-soft: #e3f8ea;
  --danger: #d92d20;
  --danger-soft: #fdecec;
  --charging: #2563eb;
  --charging-soft: #e6edfe;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.06), 0 1px 3px rgba(16, 24, 40, 0.06);
  --shadow-md: 0 4px 10px rgba(16, 24, 40, 0.08);
  --radius: 12px;
  --radius-sm: 8px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --bg-elevated: #191c22;
    --bg-inset: #22262e;
    --text: #e7e9ec;
    --text-muted: #9aa1ac;
    --border: #2b2f38;
    --accent: #2dd4bf;
    --accent-strong: #5eead4;
    --accent-soft: #103c38;
    --success: #34d399;
    --success-soft: #123527;
    --danger: #f87171;
    --danger-soft: #3a1a1a;
    --charging: #60a5fa;
    --charging-soft: #172a4d;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 20px rgba(0, 0, 0, 0.35);
  }
}

* {
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
}

h1 {
  font-size: 1.5rem;
  margin: 0 0 1.25rem;
  letter-spacing: -0.01em;
}

h2 {
  font-size: 1.05rem;
  margin: 0 0 0.75rem;
  letter-spacing: -0.01em;
}

/* --- Nav --- */

nav {
  display: flex;
  gap: 0.25rem;
  align-items: center;
  padding: 0.85rem 1.5rem;
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  margin-right: 1.25rem;
  color: var(--text);
  text-decoration: none;
  font-size: 1.05rem;
}

.brand-mark {
  font-size: 1.2rem;
}

nav a.nav-link {
  text-decoration: none;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.9rem;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: background 0.15s ease, color 0.15s ease;
}

nav a.nav-link:hover {
  color: var(--text);
  background: var(--bg-inset);
}

nav a.nav-link.active {
  color: var(--accent-strong);
  background: var(--accent-soft);
}

.logout-form {
  margin-left: auto;
}

/* --- Layout --- */

main {
  padding: 2rem 1.5rem 3rem;
  max-width: 1000px;
  margin: 0 auto;
}

.page-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.page-header h1 {
  margin: 0;
}

/* --- Stat cards --- */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  box-shadow: var(--shadow);
}

.card-head {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.6rem;
}

.card-icon {
  font-size: 1rem;
  line-height: 1;
}

.card h2 {
  margin: 0;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  font-weight: 700;
}

.card .value {
  margin: 0;
  font-size: 1.6rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.card .sub {
  margin: 0.25rem 0 0;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* --- Status pill --- */

.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 700;
}

.pill::before {
  content: "";
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: currentColor;
}

.pill.online {
  color: var(--success);
  background: var(--success-soft);
}

.pill.offline {
  color: var(--danger);
  background: var(--danger-soft);
}

.pill.charging {
  color: var(--charging);
  background: var(--charging-soft);
}

.pill.charging::before {
  animation: pulse 1.4s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

/* --- Section --- */

section.block {
  margin-bottom: 2.5rem;
}

/* --- Table --- */

.table-wrap {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.table-scroll {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

th {
  text-align: left;
  padding: 0.75rem 1rem;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  background: var(--bg-inset);
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

td {
  text-align: left;
  padding: 0.7rem 1rem;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}

tbody tr:last-child td {
  border-bottom: none;
}

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

td.num, th.num {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

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

.empty-row td {
  text-align: center;
  padding: 2.5rem 1rem;
  color: var(--text-muted);
}

/* --- Forms & buttons --- */

label {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 600;
}

input, select {
  font: inherit;
  color: var(--text);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.65rem;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

button, .btn {
  font: inherit;
  font-weight: 600;
  font-size: 0.88rem;
  cursor: pointer;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.9rem;
  background: var(--accent);
  color: #ffffff;
  transition: background 0.15s ease, filter 0.15s ease;
}

button:hover, .btn:hover {
  filter: brightness(1.08);
}

button.btn-ghost, .btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border-color: var(--border);
}

button.btn-ghost:hover {
  background: var(--bg-inset);
  color: var(--text);
}

button.btn-danger {
  background: transparent;
  color: var(--danger);
  border-color: var(--danger-soft);
}

button.btn-danger:hover {
  background: var(--danger-soft);
}

.inline-form {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.stacked-form {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  max-width: 360px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
}

.filter-bar {
  margin-bottom: 1rem;
}

/* --- Login --- */

.login-body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  margin: 0;
  background:
    radial-gradient(circle at 15% 20%, var(--accent-soft), transparent 45%),
    radial-gradient(circle at 85% 80%, var(--charging-soft), transparent 45%),
    var(--bg);
}

.login-box {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.25rem 2rem;
  width: 100%;
  max-width: 320px;
  box-shadow: var(--shadow-md);
}

.login-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.3rem;
  font-weight: 700;
  margin: 0 0 1.5rem;
}

.login-box form {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.login-box button {
  margin-top: 0.25rem;
}

.error {
  color: var(--danger);
  background: var(--danger-soft);
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.75rem;
  font-size: 0.85rem;
  margin: 0 0 0.25rem;
}