/* ==========================================================================
   CSS Variables – Theme & Spacing
   ========================================================================== */
:root {
  /* Dark theme palette (default) */
  --bg-primary: #0a0a0a;
  --bg-secondary: #141414;
  --bg-card: #1a1a1a;
  --bg-card-hover: #222222;
  --border-color: #333;
  --border-light: #2a2a2a;

  --text-primary: #e0e0e0;
  --text-secondary: #888;
  --text-muted: #555;

  --accent-green: #10b981;
  --accent-green-light: #34d399;
  --accent-red: #ef4444;
  --accent-red-light: #f87171;
  --accent-yellow: #f59e0b;
  --accent-yellow-light: #fbbf24;
  --accent-blue: #3b82f6;
  --accent-blue-light: #60a5fa;

  --shadow-sm: 0 2px 4px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 8px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 16px rgba(0,0,0,0.5);

  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;

  --font-sans: 'Segoe UI', system-ui, -apple-system, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', monospace;

  /* Text on accent backgrounds */
  --text-on-accent-green: #000;
  --text-on-accent-red: #fff;
  --text-on-accent-yellow: #000;
  --text-on-accent-blue: #fff;
}

/* Light theme */
[data-theme="light"] {
  --bg-primary: #f5f5f5;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f0f0f0;
  --border-color: #ddd;
  --border-light: #e8e8e8;

  --text-primary: #1a1a1a;
  --text-secondary: #666;
  --text-muted: #999;

  --shadow-sm: 0 2px 4px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 8px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 16px rgba(0,0,0,0.12);

  /* Text on accent backgrounds for light theme */
  --text-on-accent-green: #000;
  --text-on-accent-red: #fff;
  --text-on-accent-yellow: #000;
  --text-on-accent-blue: #fff;
}

/* Theme transition */
*,
*::before,
*::after {
  transition: background-color var(--transition-normal), border-color var(--transition-normal), color var(--transition-normal), box-shadow var(--transition-normal);
}

/* ==========================================================================
   Reset & Base
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 14px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  padding: 1rem;
}

/* Scrollbar styling */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ==========================================================================
   Layout
   ========================================================================== */
.container {
  max-width: 1600px;
  margin: 0 auto;
}

header {
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-card) 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-md);
}

h1 {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.subtitle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  color: var(--text-secondary);
  font-size: 0.75rem;
}

.edit-url {
  color: var(--text-secondary);
  font-size: 0.7rem;
  cursor: pointer;
  text-decoration: underline;
  transition: color var(--transition-fast);
}
.edit-url:hover { color: var(--accent-green); }

.refresh-time {
  color: var(--text-muted);
  font-size: 0.7rem;
}

/* ==========================================================================
   Status Badge
   ========================================================================== */
.status-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.status-online { background: var(--accent-green); color: #000; }
.status-offline { background: var(--accent-red); color: var(--text-on-accent, #fff); }
.status-warning { background: var(--accent-yellow); color: #000; }

/* ==========================================================================
   Grid System
   ========================================================================== */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
  margin-bottom: 1rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.1rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
}
.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--border-light);
}

.card-title {
  font-size: 0.6rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
  font-weight: 600;
}

.card-value {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
  font-family: var(--font-mono);
}

.card-label {
  font-size: 0.6rem;
  color: var(--text-secondary);
}

.highlight-green { color: var(--accent-green); }
.highlight-red { color: var(--accent-red); }
.highlight-yellow { color: var(--accent-yellow); }
.highlight-blue { color: var(--accent-blue); }

/* Large card spanning full width */
.large-card {
  grid-column: 1 / -1;
}

/* ==========================================================================
   Stat Rows
   ========================================================================== */
.stat-row {
  display: flex;
  justify-content: space-between;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border-light);
}
.stat-row:last-child { border-bottom: none; }

.stat-label { color: var(--text-secondary); font-size: 0.75rem; }
.stat-value { color: var(--text-primary); font-weight: 600; font-size: 0.75rem; font-family: var(--font-mono); }

/* ==========================================================================
   Progress Bar
   ========================================================================== */
.progress-bar {
  background: var(--bg-secondary);
  border-radius: 4px;
  height: 6px;
  overflow: hidden;
  margin-top: 0.4rem;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-green), var(--accent-green-light));
  border-radius: 4px;
  transition: width var(--transition-normal);
}

/* ==========================================================================
   Metrics Grid (inside large cards)
   ========================================================================== */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 0.5rem;
  margin-top: 0.75rem;
}

.metric-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 0.6rem;
}

.metric-value {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.15rem;
  font-family: var(--font-mono);
}

.metric-label {
  font-size: 0.55rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

/* ==========================================================================
   Hashrate Line Chart
   ========================================================================== */
.hashrate-chart {
  width: 100%;
  height: 60px;
  margin-top: 0.5rem;
}

.hashrate-line-chart {
  width: 100%;
  height: 100%;
  display: block;
}

.chart-grid {
  stroke: var(--border-light);
}

.chart-point {
  stroke: var(--bg-card);
  stroke-width: 2;
  transition: r var(--transition-fast);
  cursor: pointer;
}

.chart-point:hover {
  r: 5;
}

.chart-label {
  font-size: 0.55rem;
  fill: var(--text-muted);
  pointer-events: none;
}

.hashrate-chart {
  position: relative;
}

/* ==========================================================================
   Chart Tooltip
   ========================================================================== */
.chart-point-tooltip {
  position: absolute;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.35rem 0.5rem;
  font-size: 0.7rem;
  color: var(--text-primary);
  pointer-events: none;
  opacity: 0;
  visibility: hidden;
  transform: translateX(-50%) translateY(4px);
  transition: opacity var(--transition-fast), visibility var(--transition-fast), transform var(--transition-fast);
  white-space: nowrap;
  z-index: 10;
  box-shadow: var(--shadow-md);
}

.chart-point-tooltip.visible {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.55rem 1.1rem;
  background: var(--accent-green);
  color: #000;
  border: none;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.8rem;
  cursor: pointer;
  transition: background var(--transition-fast), transform var(--transition-fast);
}
.btn:hover { background: var(--accent-green-light); transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn:focus-visible { outline: 2px solid var(--accent-green); outline-offset: 2px; }

.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}
.btn-secondary:hover { background: var(--bg-card); border-color: var(--border-light); }

.btn-danger {
  background: var(--accent-red);
  color: var(--text-on-accent-red);
}
.btn-danger:hover { background: var(--accent-red-light); }

.btn-sm { padding: 0.35rem 0.7rem; font-size: 0.7rem; }

/* ==========================================================================
   Form Elements
   ========================================================================== */
.input-group { margin-bottom: 1rem; }

.input-label {
  display: block;
  color: var(--text-secondary);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.4rem;
}

.input-field {
  width: 100%;
  padding: 0.6rem 0.75rem;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.8rem;
  font-family: var(--font-mono);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.input-field:focus {
  outline: none;
  border-color: var(--accent-green);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.2);
}
.input-field::placeholder { color: var(--text-muted); }

.input-hint {
  display: block;
  margin-top: 0.3rem;
  font-size: 0.55rem;
  color: var(--text-muted);
}

.checkbox-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1rem;
}
.checkbox-group input[type="checkbox"] {
  width: 16px; height: 16px;
  accent-color: var(--accent-green);
}
.checkbox-group label { font-size: 0.75rem; color: var(--text-secondary); cursor: pointer; }

/* ==========================================================================
   Config Panel (Connection Screen)
   ========================================================================== */
.config-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  max-width: 420px;
  margin: 3rem auto;
  box-shadow: var(--shadow-lg);
}

.config-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  text-align: center;
}

.config-actions {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  margin-top: 1rem;
}

/* ==========================================================================
   Settings Modal
   ========================================================================== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}
.modal-overlay.open {
  opacity: 1;
  visibility: visible;
}

.modal {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  width: 100%;
  max-width: 420px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  transform: translateY(20px);
  transition: transform var(--transition-normal);
}
.modal-overlay.open .modal { transform: translateY(0); }

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}
.modal-title { font-size: 1rem; font-weight: 600; }
.modal-close {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 1.25rem;
  cursor: pointer;
  line-height: 1;
  padding: 0.25rem;
}
.modal-close:hover { color: var(--text-primary); }

/* ==========================================================================
   Skeleton Loading
   ========================================================================== */
.skeleton {
  animation: pulse 1.5s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.skeleton-line {
  height: 10px;
  background: linear-gradient(90deg, var(--bg-secondary) 25%, var(--bg-card) 50%, var(--bg-secondary) 75%);
  background-size: 200% 100%;
  border-radius: 4px;
  margin-bottom: 0.5rem;
  animation: shimmer 1.5s infinite;
}
@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ==========================================================================
   Loading & Empty States
   ========================================================================== */
.loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem;
  color: var(--text-secondary);
  gap: 1rem;
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border-color);
  border-top-color: var(--accent-green);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.empty-state {
  text-align: center;
  padding: 3rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Toast Notifications
   ========================================================================== */
#toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  z-index: 2000;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 500;
  max-width: 320px;
  box-shadow: var(--shadow-lg);
  transform: translateX(120%);
  opacity: 0;
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}
.toast.show { transform: translateX(0); opacity: 1; }

.toast-info { background: var(--accent-blue); color: var(--text-on-accent-blue); }
.toast-success { background: var(--accent-green); color: var(--text-on-accent-green); }
.toast-warning { background: var(--accent-yellow); color: var(--text-on-accent-yellow); }
.toast-error { background: var(--accent-red); color: var(--text-on-accent-red); }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 768px) {
  html { font-size: 13px; }
  body { padding: 0.75rem; }
  .grid { grid-template-columns: 1fr; }
  .large-card { grid-column: auto; }
  .subtitle { flex-direction: column; align-items: flex-start; }
  #toast-container { left: 1rem; right: 1rem; bottom: 1rem; }
  .toast { max-width: none; }
}

@media (max-width: 480px) {
  .card { padding: 0.9rem; }
  .card-value { font-size: 1.3rem; }
  .metrics-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ==========================================================================
   Utility
   ========================================================================== */
.hidden { display: none !important; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}