:root {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  
  /* Color Palette - Blue, Dark Blue, White */
  --bg-base: #030712;         /* Pitch black / dark navy */
  --bg-surface: rgba(15, 23, 42, 0.65); /* Glassmorphism surface */
  --bg-sidebar: #090d16;
  --bg-header: rgba(3, 7, 18, 0.7);
  
  --color-primary: #3b82f6;    /* Electric Blue */
  --color-primary-hover: #2563eb;
  --color-accent: #60a5fa;     /* Light Blue */
  --color-success: #10b981;    /* Emerald */
  --color-danger: #ef4444;     /* Red */
  --color-warning: #f59e0b;    /* Amber */
  
  --text-primary: #f9fafb;     /* White */
  --text-secondary: #9ca3af;   /* Muted Gray */
  --text-muted: #6b7280;
  
  --border-color: rgba(255, 255, 255, 0.08);
  --border-radius: 12px;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

/* Light Mode Override (if toggled) */
.light-mode {
  --bg-base: #f3f4f6;
  --bg-surface: rgba(255, 255, 255, 0.8);
  --bg-sidebar: #ffffff;
  --bg-header: rgba(243, 244, 246, 0.8);
  
  --color-primary: #1d4ed8;
  --color-primary-hover: #1e40af;
  --color-accent: #3b82f6;
  
  --text-primary: #111827;
  --text-secondary: #4b5563;
  --text-muted: #9ca3af;
  
  --border-color: rgba(0, 0, 0, 0.08);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-base);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* Glassmorphism utility */
.glass {
  background: var(--bg-surface);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-lg);
}

/* Layout definitions */
.layout-wrapper {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: 100vh;
}

@media (max-width: 768px) {
  .layout-wrapper {
    grid-template-columns: 1fr;
  }
  .sidebar {
    display: none; /* simple hidden on mobile, can make mobile drawer later */
  }
}

/* Sidebar Styles */
.sidebar {
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  padding: 24px;
  display: flex;
  flex-direction: column;
  height: 100vh;
  position: sticky;
  top: 0;
}

.logo-container {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 32px;
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--color-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.5px;
}

.nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex-grow: 1;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--border-radius);
  font-size: 0.95rem;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
  background: rgba(59, 130, 246, 0.15);
  border-left: 3px solid var(--color-primary);
}

.sidebar-footer {
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
}

/* Main Area Styles */
.main-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.header {
  background: var(--bg-header);
  backdrop-filter: blur(8px);
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 10;
}

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

.user-profile {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-name {
  font-size: 0.9rem;
  font-weight: 500;
}

.user-role {
  font-size: 0.75rem;
  background: rgba(59, 130, 246, 0.2);
  color: var(--color-accent);
  padding: 2px 8px;
  border-radius: 9999px;
  text-transform: uppercase;
  font-weight: 600;
}

.content-body {
  padding: 32px;
  flex-grow: 1;
  overflow-y: auto;
  animation: fadeIn var(--transition-normal);
}

/* UI Controls */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--border-radius);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-primary {
  background-color: var(--color-primary);
  color: white;
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

.btn-danger {
  background-color: var(--color-danger);
  color: white;
}

.btn-danger:hover {
  background-color: #dc2626;
}

/* Grid & Dashboard Widgets */
.dashboard-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  margin-bottom: 32px;
}

.card {
  padding: 24px;
}

.card-title {
  font-size: 0.85rem;
  text-transform: uppercase;
  color: var(--text-secondary);
  font-weight: 600;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.card-value {
  font-size: 2rem;
  font-weight: 700;
}

.card-subtext {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Form Styles */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.form-control {
  width: 100%;
  padding: 10px 14px;
  font-family: var(--font-sans);
  background-color: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  color: var(--text-primary);
  outline: none;
  transition: all var(--transition-fast);
}

.form-control:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.2);
}

/* Login Page specific styling */
.login-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 16px;
}

.login-card {
  width: 100%;
  max-width: 420px;
  padding: 40px;
  text-align: center;
}

.login-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.login-subtitle {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* Table styling */
.table-wrapper {
  overflow-x: auto;
  margin-top: 24px;
}

.table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.table th, .table td {
  padding: 16px;
  border-bottom: 1px solid var(--border-color);
}

.table th {
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
}

.table tr:hover {
  background-color: rgba(255, 255, 255, 0.01);
}

/* Modal styles */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  z-index: 100;
  align-items: center;
  justify-content: center;
}

.modal.show {
  display: flex;
}

.modal-content {
  width: 100%;
  max-width: 500px;
  padding: 32px;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}

.modal-close {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Notes Board */
.notes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
  margin-top: 24px;
}

.note-card {
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 200px;
  position: relative;
  transition: transform var(--transition-fast);
}

.note-card:hover {
  transform: translateY(-4px);
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.badge {
  padding: 4px 8px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.badge-success { background: rgba(16, 185, 129, 0.2); color: #34d399; }
.badge-warning { background: rgba(245, 158, 11, 0.2); color: #fbbf24; }
.badge-danger { background: rgba(239, 68, 68, 0.2); color: #f87171; }
.badge-info { background: rgba(59, 130, 246, 0.2); color: #60a5fa; }