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

:root {
  --bg: #0d1117;
  --bg-secondary: #161b22;
  --bg-card: #1c2129;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent: #58a6ff;
  --green: #67d4a8;
  --red: #f55b5b;
  --orange: #f5a05b;
}

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

.hidden {
  display: none !important;
}

/* Login */
#login-section {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
}

.login-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
  width: 100%;
  max-width: 360px;
}

.login-box h1 {
  font-size: 1.5rem;
  margin-bottom: 0.25rem;
}

.login-box .subtitle {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 1.5rem;
}

.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 0.375rem;
}

.form-group input {
  width: 100%;
  padding: 0.625rem 0.75rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-size: 0.875rem;
  outline: none;
}

.form-group input:focus {
  border-color: var(--accent);
}

.login-btn {
  width: 100%;
  padding: 0.625rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  margin-top: 0.5rem;
}

.login-btn:hover {
  opacity: 0.9;
}

.login-error {
  color: var(--red);
  font-size: 0.8rem;
  margin-top: 0.75rem;
  min-height: 1.2em;
}

/* Dashboard layout */
#dashboard-section {
  display: grid;
  grid-template-columns: 1fr;
  grid-template-rows: auto 1fr;
  min-height: 100vh;
}

/* Top bar */
.topbar {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.25rem;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
}

.topbar h1 {
  font-size: 1.125rem;
  font-weight: 600;
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.status-indicator::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--text-muted);
}

.status-indicator.connected::before {
  background: var(--green);
}

.status-indicator.disconnected::before,
.status-indicator.error::before {
  background: var(--red);
}

#logout-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 0.375rem 0.75rem;
  border-radius: 6px;
  font-size: 0.8rem;
  cursor: pointer;
}

#logout-btn:hover {
  color: var(--text);
  border-color: var(--text-muted);
}

/* Loader */
.loader {
  width: 24px;
  height: 24px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-top: 1rem;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Single node layout */
.main-content.single-node {
  max-width: 960px;
  margin: 0 auto;
  width: 100%;
}

/* Main content */
.main-content {
  padding: 1.5rem;
  overflow-y: auto;
}

.detail-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.detail-header h2 {
  font-size: 1.25rem;
}

.badge {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.625rem;
  border-radius: 999px;
}

.badge.online {
  background: rgba(103, 212, 168, 0.15);
  color: var(--green);
}

.badge.offline {
  background: rgba(139, 148, 158, 0.15);
  color: var(--text-muted);
}

.badge.primary-badge {
  background: rgba(88, 166, 255, 0.15);
  color: var(--accent);
}

/* Cards grid */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem;
}

.card-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.5rem;
}

.card-value {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.2;
}

.card-value.time {
  font-size: 0.9rem;
  font-weight: 400;
}

.card-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.battery-bar {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  margin-top: 0.625rem;
  overflow: hidden;
}

.battery-fill {
  height: 100%;
  border-radius: 2px;
  transition: width 0.3s;
}

/* Charts */
.charts-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.chart-container {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem;
}

.chart-container h3 {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.75rem;
}

.chart-container canvas {
  height: 200px !important;
}

/* Empty state */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-muted);
  text-align: center;
  padding: 2rem;
}

.empty-state h3 {
  font-size: 1rem;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.empty-state p {
  font-size: 0.875rem;
  max-width: 400px;
}

/* Responsive */
@media (max-width: 768px) {
  .charts-section {
    grid-template-columns: 1fr;
  }

  .cards {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  }
}