/* Core Platform Design System & Global Styles */
:root {
  /* Color Palette - Light Theme */
  --bg-app: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-alt: #f1f5f9;
  --bg-surface-hover: #e2e8f0;
  --border-subtle: #e2e8f0;
  --border-focus: #3b82f6;

  --text-main: #0f172a;
  --text-muted: #64748b;
  --text-subtle: #94a3b8;
  --text-inverse: #ffffff;

  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-subtle: #dbeafe;
  --primary-text: #1e40af;

  --success: #10b981;
  --success-subtle: #d1fae5;
  --success-text: #065f46;

  --warning: #f59e0b;
  --warning-subtle: #fef3c7;
  --warning-text: #92400e;

  --danger: #ef4444;
  --danger-subtle: #fee2e2;
  --danger-text: #991b1b;

  --info: #06b6d4;
  --info-subtle: #cffafe;
  --info-text: #155e75;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Elevation */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.08);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.12), 0 8px 10px -6px rgba(0, 0, 0, 0.08);

  /* Dimensions */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-app: #090d16;
  --bg-surface: #111827;
  --bg-surface-alt: #1f2937;
  --bg-surface-hover: #374151;
  --border-subtle: #2d3748;
  --border-focus: #60a5fa;

  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-subtle: #64748b;
  --text-inverse: #0f172a;

  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --primary-subtle: rgba(59, 130, 246, 0.15);
  --primary-text: #93c5fd;

  --success: #10b981;
  --success-subtle: rgba(16, 185, 129, 0.15);
  --success-text: #6ee7b7;

  --warning: #f59e0b;
  --warning-subtle: rgba(245, 158, 11, 0.15);
  --warning-text: #fcd34d;

  --danger: #ef4444;
  --danger-subtle: rgba(239, 68, 68, 0.15);
  --danger-text: #fca5a5;

  --info: #06b6d4;
  --info-subtle: rgba(6, 182, 212, 0.15);
  --info-text: #67e8f9;

  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  transition: background-color 0.25s ease, color 0.25s ease;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition);
}
a:hover {
  text-decoration: underline;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 500;
  font-size: 0.9rem;
  padding: 8px 16px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none !important;
  user-select: none;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--primary);
  color: #ffffff;
}
.btn-primary:hover {
  background-color: var(--primary-hover);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--bg-surface-alt);
  color: var(--text-main);
  border-color: var(--border-subtle);
}
.btn-secondary:hover {
  background-color: var(--bg-surface-hover);
}

.btn-danger {
  background-color: var(--danger);
  color: #ffffff;
}
.btn-danger:hover {
  opacity: 0.9;
}

.btn-outline {
  background: transparent;
  border-color: var(--border-subtle);
  color: var(--text-main);
}
.btn-outline:hover {
  background-color: var(--bg-surface-alt);
  border-color: var(--text-muted);
}

.btn-sm {
  padding: 5px 10px;
  font-size: 0.8rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 12px 24px;
  font-size: 1rem;
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.badge-success {
  background-color: var(--success-subtle);
  color: var(--success-text);
}
.badge-warning {
  background-color: var(--warning-subtle);
  color: var(--warning-text);
}
.badge-danger {
  background-color: var(--danger-subtle);
  color: var(--danger-text);
}
.badge-info {
  background-color: var(--info-subtle);
  color: var(--info-text);
}
.badge-neutral {
  background-color: var(--bg-surface-hover);
  color: var(--text-muted);
}

/* Form Controls */
.form-group {
  margin-bottom: 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
}

.form-control {
  width: 100%;
  padding: 10px 14px;
  font-size: 0.95rem;
  font-family: inherit;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background-color: var(--bg-surface);
  color: var(--text-main);
  outline: none;
  transition: var(--transition);
}

.form-control:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--primary-subtle);
}

/* Cards & Panels */
.card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

/* Toast Notifications */
#toast-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  min-width: 300px;
  max-width: 420px;
  padding: 14px 18px;
  background-color: var(--bg-surface);
  color: var(--text-main);
  border: 1px solid var(--border-subtle);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.9rem;
  animation: slideInRight 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  transition: transform 0.2s, opacity 0.2s;
}

.toast-success { border-left-color: var(--success); }
.toast-error { border-left-color: var(--danger); }
.toast-warning { border-left-color: var(--warning); }
.toast-info { border-left-color: var(--info); }

@keyframes slideInRight {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

/* Modal Overlay */
.modal-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.25s ease, visibility 0.25s ease;
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  width: 90%;
  max-width: 560px;
  max-height: 90vh;
  overflow-y: auto;
  padding: 24px;
  box-shadow: var(--shadow-xl);
  transform: scale(0.95);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-overlay.active .modal-content {
  transform: scale(1);
}

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

.modal-title {
  font-size: 1.25rem;
  font-weight: 600;
}

.modal-close {
  background: transparent;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  color: var(--text-muted);
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 48px 24px;
  color: var(--text-muted);
}
.empty-state-icon {
  font-size: 3rem;
  margin-bottom: 12px;
  opacity: 0.6;
}
.empty-state-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 6px;
}

/* Loading Skeleton */
.skeleton {
  background: linear-gradient(90deg, var(--bg-surface-alt) 25%, var(--bg-surface-hover) 50%, var(--bg-surface-alt) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-sm);
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}