:root {
  /* Light Mode Variables */
  --primary-color: #6366f1;
  --primary-hover: #4f46e5;
  --secondary-color: #1e293b;
  --light-color: #f8fafc;
  --dark-color: #0f172a;
  --gray-color: #64748b;
  --border-color: #e2e8f0;
  --success-color: #10b981;
  --danger-color: #ef4444;
  --transition-speed: 0.3s;
  --sidebar-width: 280px;
  --sidebar-width-collapsed: 80px;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  
  /* Background Colors */
  --body-bg: #f1f5f9;
  --card-bg: white;
  --header-bg: #f8fafc;
  --sidebar-bg: white;
  
  /* Text Colors */
  --text-color: #334155;
  --text-muted: #64748b;
  --heading-color: #0f172a;
  
  /* Form Elements */
  --input-bg: white;
  --input-border: #e2e8f0;
  --input-text: #334155;
  --input-focus-border: #6366f1;
  --input-focus-shadow: rgba(99, 102, 241, 0.1);
  --input-disabled-bg: #f8fafc;
  
  /* Table */
  --table-header-bg: #f8fafc;
  --table-row-hover: rgba(99, 102, 241, 0.05);
  --table-border: #e2e8f0;
}

/* Dark Mode Variables */
.dark-mode {
  /* Background Colors */
  --body-bg: #0f172a;
  --card-bg: #1e293b;
  --header-bg: #1e293b;
  --sidebar-bg: #1e293b;
  
  /* Text Colors */
  --text-color: #e2e8f0;
  --text-muted: #94a3b8;
  --heading-color: #f8fafc;
  
  /* Border Color */
  --border-color: #334155;
  
  /* Form Elements */
  --input-bg: #0f172a;
  --input-border: #334155;
  --input-text: #e2e8f0;
  --input-focus-border: #818cf8;
  --input-focus-shadow: rgba(129, 140, 248, 0.2);
  --input-disabled-bg: #1e293b;
  
  /* Table */
  --table-header-bg: #1e293b;
  --table-row-hover: rgba(99, 102, 241, 0.1);
  --table-border: #334155;
  
  /* Shadow */
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -2px rgba(0, 0, 0, 0.2);
}

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

body {
  font-family: var(--font-family);
  display: flex;
  min-height: 100vh;
  background-color: var(--body-bg);
  color: var(--text-color);
  overflow-x: hidden;
}

body.sidebar-open {
  overflow: hidden;
}

.sidebar {
  width: var(--sidebar-width);
  height: 100vh;
  background-color: var(--sidebar-bg);
  color: var(--text-muted);
  position: fixed;
  transition: all var(--transition-speed) ease;
  padding: 1.5rem 0 0 0;
  overflow-y: auto;
  box-shadow: 1px 0 10px rgba(0, 0, 0, 0.05);
  border-right: 1px solid var(--border-color);
  z-index: 100;
  left: 0;
}

.sidebar.collapsed {
  width: var(--sidebar-width-collapsed);
}

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

.logo-container {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
}

.logo {
  height: 80px;
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-speed);
  color: var(--heading-color);
  position: absolute;
}

.sidebar.collapsed .logo-text {
  opacity: 0;
  display: none;
}

.toggle-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 1.25rem;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.toggle-btn:hover {
  background-color: var(--body-bg);
  color: var(--heading-color);
}

.sidebar-menu {
  list-style: none;
  padding: 0 0.75rem;
}

.sidebar-menu a {
  margin-bottom: 0.25rem;
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  transition: all var(--transition-speed);
  border-radius: 8px;
  text-decoration: none;
  color: var(--text-muted);
  font-weight: 500;
}

.sidebar-menu a:hover {
  background-color: var(--body-bg);
  color: var(--heading-color);
}

.sidebar-menu a.active {
  background-color: rgba(99, 102, 241, 0.1);
  color: var(--primary-color);
}

.menu-icon {
  margin-right: 12px;
  font-size: 1.25rem;
  min-width: 24px;
  text-align: center;
  transition: transform 0.2s ease;
}

.sidebar-menu a:hover .menu-icon {
  transform: translateX(2px);
}

.menu-text {
  white-space: nowrap;
  opacity: 1;
  transition: opacity var(--transition-speed);
}

.sidebar.collapsed .menu-text {
  opacity: 0;
  display: none;
}

.sidebar-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 90;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-speed), visibility var(--transition-speed);
}

body.sidebar-open .sidebar-overlay {
  opacity: 1;
  visibility: visible;
}

.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: 2rem;
  transition: margin-left var(--transition-speed);
  max-width: 100%;
}

.main-content.expanded {
  margin-left: var(--sidebar-width-collapsed);
}

.page-title {
  margin-bottom: 1.5rem;
  color: var(--heading-color);
  font-weight: 700;
  font-size: 1.75rem;
}

.card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--card-shadow);
  margin-bottom: 1.5rem;
  border: 1px solid var(--border-color);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background-color: var(--primary-color);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 500;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  gap: 0.5rem;
}

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

.btn i {
  font-size: 0.875rem;
}

.mobile-toggle-btn {
  display: none;
  position: fixed;
  top: 1rem;
  left: 1rem;
  background-color: var(--primary-color);
  border: none;
  color: white;
  width: 40px;
  height: 40px;
  border-radius: 8px;
  font-size: 1.25rem;
  z-index: 110;
  cursor: pointer;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  transition: background-color 0.2s ease;
}

.mobile-toggle-btn:hover {
  background-color: var(--primary-hover);
}

/* Dark mode toggle button */
.theme-toggle {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  color: var(--text-color);
  width: 36px;
  height: 36px;
  border-radius: 8px;
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--card-shadow);
  transition: all 0.2s ease;
}

.theme-toggle:hover {
  transform: translateY(-2px);
  background-color: var(--hover-bg);
}

/* Theme toggle container in sidebar */
.sidebar-theme-toggle {
  padding: 0.75rem 1.25rem;
  margin-top: auto;
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-label {
  color: var(--text-muted);
  margin-right: 0.75rem;
  font-size: 0.9rem;
}

.sidebar.collapsed .theme-label {
  display: none;
}

.sidebar-theme-toggle::before {
  content: "";
}

.sidebar.collapsed .sidebar-theme-toggle::before {
  display: none;
}

/* Responsive */
@media (max-width: 768px) {
  .mobile-toggle-btn {
    display: flex;
    align-items: center;
    justify-content: center;
  }
  
  .sidebar {
    width: var(--sidebar-width);
    transform: translateX(-100%);
  }
  
  .sidebar.expanded {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
    padding: 1.5rem;
  }
  
  .main-content.expanded {
    margin-left: 0;
  }
  
  .main-content {
    padding-top: 4rem;
  }
  
  .sidebar .toggle-btn {
    display: none;
  }
}