/* ===================================================================
   Smart School System - Professional Design System
   Modern, Clean, Responsive, Mobile-First
   =================================================================== */

/* ---------- CSS Variables (Theme) ---------- */
:root {
  /* Brand Colors - Educational Palette */
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-light: #eef2ff;
  --primary-dark: #3730a3;
  
  --secondary: #0ea5e9;
  --secondary-light: #e0f2fe;
  
  --accent: #f59e0b;
  --accent-light: #fef3c7;
  
  --success: #10b981;
  --success-light: #d1fae5;
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --danger: #ef4444;
  --danger-light: #fee2e2;
  --info: #3b82f6;
  --info-light: #dbeafe;
  
  /* Neutrals */
  --white: #ffffff;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Arial, sans-serif;
  --font-ar: 'Cairo', 'Tajawal', Tahoma, sans-serif;
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
  --shadow-2xl: 0 25px 50px -12px rgba(0,0,0,0.25);
  
  /* Transitions */
  --transition: all 0.2s ease;
  --transition-slow: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Sidebar */
  --sidebar-width: 260px;
  --sidebar-collapsed: 80px;
  --header-height: 70px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  color: var(--gray-800);
  background: var(--gray-50);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body[dir="rtl"] {
  font-family: var(--font-ar);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

a:hover {
  color: var(--primary-hover);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--gray-900);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

/* ---------- Container ---------- */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: var(--transition);
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
  text-align: center;
}

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

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

.btn-secondary {
  background: white;
  color: var(--gray-700);
  border-color: var(--gray-200);
}

.btn-secondary:hover {
  background: var(--gray-50);
  border-color: var(--gray-300);
}

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

.btn-outline {
  background: transparent;
  color: var(--primary);
  border-color: var(--primary);
}

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

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.0625rem;
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.8125rem;
}

.btn-block {
  width: 100%;
}

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

.form-label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--gray-700);
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 0.9375rem;
  font-family: inherit;
  color: var(--gray-900);
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  transition: var(--transition);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-control::placeholder {
  color: var(--gray-400);
}

select.form-control {
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 1rem;
  padding-right: 2.5rem;
  appearance: none;
}

body[dir="rtl"] select.form-control {
  background-position: left 0.75rem center;
  padding-right: 1rem;
  padding-left: 2.5rem;
}

.form-check {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.form-check input[type="checkbox"] {
  width: 1.125rem;
  height: 1.125rem;
  cursor: pointer;
  accent-color: var(--primary);
}

/* ---------- Alerts ---------- */
.alert {
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  margin-bottom: 1rem;
  border-left: 4px solid;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.9375rem;
}

body[dir="rtl"] .alert {
  border-left: none;
  border-right: 4px solid;
}

.alert-success { background: var(--success-light); color: #065f46; border-color: var(--success); }
.alert-danger { background: var(--danger-light); color: #991b1b; border-color: var(--danger); }
.alert-warning { background: var(--warning-light); color: #92400e; border-color: var(--warning); }
.alert-info { background: var(--info-light); color: #1e40af; border-color: var(--info); }

/* ---------- Cards ---------- */
.card {
  background: white;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  border: 1px solid var(--gray-100);
  transition: var(--transition);
}

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

.card-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--gray-100);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.card-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--gray-900);
  margin: 0;
}

.card-body {
  padding: 1.5rem;
}

/* ---------- Badges ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  line-height: 1.25;
}

.badge-primary { background: var(--primary-light); color: var(--primary-dark); }
.badge-success { background: var(--success-light); color: #065f46; }
.badge-danger { background: var(--danger-light); color: #991b1b; }
.badge-warning { background: var(--warning-light); color: #92400e; }
.badge-info { background: var(--info-light); color: #1e40af; }
.badge-secondary { background: var(--gray-100); color: var(--gray-700); }

/* ---------- Tables ---------- */
.table-responsive {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  background: white;
  -webkit-overflow-scrolling: touch;
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.table thead {
  background: var(--gray-50);
}

.table th {
  padding: 1rem;
  text-align: start;
  font-weight: 600;
  color: var(--gray-700);
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 1px solid var(--gray-200);
}

.table td {
  padding: 1rem;
  border-bottom: 1px solid var(--gray-100);
  color: var(--gray-800);
}

.table tbody tr {
  transition: var(--transition);
}

.table tbody tr:hover {
  background: var(--gray-50);
}

.table tbody tr:last-child td {
  border-bottom: none;
}

/* ---------- Utilities ---------- */
.text-center { text-align: center; }
.text-start { text-align: start; }
.text-end { text-align: end; }
.text-muted { color: var(--gray-500); }
.text-primary { color: var(--primary); }
.text-success { color: var(--success); }
.text-danger { color: var(--danger); }

.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-1 { gap: 0.25rem; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 0.75rem; }
.gap-4 { gap: 1rem; }

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }

.w-100 { width: 100%; }

/* ---------- Animations ---------- */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
  from { opacity: 0; transform: translateX(-20px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.fade-in { animation: fadeIn 0.4s ease forwards; }
.slide-in { animation: slideIn 0.4s ease forwards; }
.pulse { animation: pulse 2s infinite; }

/* ---------- Responsive Grid ---------- */
.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 992px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  h1 { font-size: 1.875rem; }
  h2 { font-size: 1.5rem; }
  .btn { padding: 0.625rem 1.25rem; }
  .card-body { padding: 1rem; }
}

/* ---------- Loading Spinner ---------- */
.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255,255,255,0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--gray-100);
}

::-webkit-scrollbar-thumb {
  background: var(--gray-300);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--gray-400);
}