:root {
  /* Premium Dark Mode Glassmorphism Palette */
  --bg-color: #0f172a;
  --bg-secondary: #1e293b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --primary: #6366f1; /* Indigo */
  --primary-hover: #4f46e5;
  --accent: #8b5cf6; /* Violet */
  --border-color: rgba(255, 255, 255, 0.1);
  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(255, 255, 255, 0.05);
  
  --sidebar-width: 280px;
  --header-height: 70px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
  margin: 0;
  font-family: var(--font-family);
  background-color: var(--bg-color);
  background-image: 
    radial-gradient(at 0% 0%, rgba(99, 102, 241, 0.15) 0px, transparent 50%),
    radial-gradient(at 100% 100%, rgba(139, 92, 246, 0.15) 0px, transparent 50%);
  background-attachment: fixed;
  color: var(--text-main);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
}

/* Glassmorphism Utilities */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
}

/* Layout */
.app-container {
  display: flex;
  width: 100%;
  min-height: 100vh;
}

/* Sidebar */
.modern-sidebar {
  width: var(--sidebar-width);
  height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 100;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  border-right: 1px solid var(--border-color);
  overflow-y: auto;
}

/* Custom Scrollbar for Sidebar */
.modern-sidebar::-webkit-scrollbar {
  width: 6px;
}
.modern-sidebar::-webkit-scrollbar-thumb {
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
}

.sidebar-header {
  height: var(--header-height);
  display: flex;
  align-items: center;
  padding: 0 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.025em;
}

.brand-logo img {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  box-shadow: 0 0 15px rgba(99, 102, 241, 0.4);
}

.user-profile {
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--border-color);
}

.user-profile img {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 2px solid var(--primary);
  padding: 2px;
}

.user-info {
  display: flex;
  flex-direction: column;
}

.user-name {
  font-weight: 600;
  font-size: 0.95rem;
}

.user-role {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.sidebar-nav {
  padding: 1rem 0.5rem;
  list-style: none;
  margin: 0;
  flex: 1;
}

.nav-item {
  margin-bottom: 0.25rem;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0.75rem 1rem;
  color: var(--text-muted);
  text-decoration: none;
  border-radius: 8px;
  transition: var(--transition);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-link i {
  font-size: 1.1rem;
  width: 24px;
  text-align: center;
  transition: var(--transition);
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  transform: translateX(4px);
}

.nav-link:hover i {
  color: var(--primary);
}

.nav-link.active {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: white;
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.nav-link.active i {
  color: white;
}

/* Main Content */
.main-wrapper {
  margin-left: var(--sidebar-width);
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  transition: var(--transition);
}

.top-header {
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 90;
}

.page-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0;
  background: linear-gradient(to right, #fff, #94a3b8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.content-area {
  padding: 2rem;
  flex: 1;
}

/* Modern Cards */
.modern-card {
  border-radius: 16px;
  margin-bottom: 1.5rem;
  overflow: hidden;
  transition: var(--transition);
}

.modern-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px 0 rgba(0, 0, 0, 0.4);
}

.card-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  background: rgba(255,255,255,0.02);
}

.card-title {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 8px;
}

.card-body {
  padding: 1.5rem;
}

.card-footer {
  padding: 1.25rem 1.5rem;
  border-top: 1px solid var(--border-color);
  background: rgba(255,255,255,0.02);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Forms & Inputs */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-main);
  font-family: var(--font-family);
  transition: var(--transition);
  box-sizing: border-box;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
  background: rgba(15, 23, 42, 0.8);
}

/* Buttons */
.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-family);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.btn-primary:hover {
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(1px);
}

/* Alerts */
.success-message {
  padding: 0.75rem 1rem;
  border-radius: 8px;
  background: rgba(16, 185, 129, 0.1);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.2);
  font-size: 0.9rem;
  display: none;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-5px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 768px) {
  .modern-sidebar {
    transform: translateX(-100%);
  }
  .main-wrapper {
    margin-left: 0;
  }
  .sidebar-open .modern-sidebar {
    transform: translateX(0);
  }
  .mobile-toggle {
    display: block;
  }
}

/* Helper Classes */
.d-none { display: none !important; }
.text-center { text-align: center; }
.mt-4 { margin-top: 1.5rem; }
.mb-4 { margin-bottom: 1.5rem; }