:root {
  --primary: #0F172A;
  --secondary: #1E293B;
  --accent: #2563EB;
  --success: #22C55E;
  --danger: #EF4444;
  --warning: #F59E0B;
  --bg-main: #F8FAFC;
  --bg-card: #FFFFFF;
  --text-main: #1E293B;
  --text-muted: #64748B;
  --border-color: #E2E8F0;
  --radius: 15px;
  --shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.05), 0 8px 10px -6px rgba(15, 23, 42, 0.05);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --primary: #1E293B;
  --secondary: #0F172A;
  --bg-main: #0B0F19;
  --bg-card: #141B2D;
  --text-main: #F8FAFC;
  --text-muted: #94A3B8;
  --border-color: #334155;
  --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
}

body {
  background-color: var(--bg-main);
  color: var(--text-main);
  font-family: 'Inter', sans-serif;
  transition: var(--transition);
  overflow-x: hidden;
}

/* Structural Engine */
#layout-wrapper {
  display: flex;
  min-height: 100vh;
}

#sidebar {
  width: 260px;
  background-color: var(--primary);
  min-height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1000;
  transition: var(--transition);
}

#main-content {
  margin-left: 260px;
  width: calc(100% - 260px);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

#top-navbar {
  background-color: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  height: 70px;
  position: sticky;
  top: 0;
  z-index: 999;
  padding: 0 1.5rem;
}

/* Premium Dashboard UI Elements */
.stat-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--accent);
  opacity: 0;
  transition: var(--transition);
}

.stat-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1);
}

.stat-card:hover::before {
  opacity: 1;
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

/* Table Design overrides */
.custom-table-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.table {
  color: var(--text-main);
  margin-bottom: 0;
}

.table th {
  background-color: var(--secondary);
  color: #FFFFFF;
  font-weight: 500;
  padding: 1rem;
  border: none;
}

.table td {
  padding: 1rem;
  vertical-align: middle;
  border-color: var(--border-color);
  background-color: var(--bg-card);
}

/* Responsive Handling Breakpoints */
@media (max-width: 992px) {
  #sidebar { left: -260px; }
  #main-content { margin-left: 0; width: 100%; }
  body.sidebar-active #sidebar { left: 0; }
}

/* Utility Animations */
.spinner-wrapper {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(15, 23, 42, 0.6);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0; visibility: hidden;
  transition: var(--transition);
}
.spinner-wrapper.show { opacity: 1; visibility: visible; }