/* ==========================================================================
   LEARNING TOLEDO - CORE DESIGN SYSTEM & VARIABLES
   ========================================================================== */

:root {
  /* Brand Palette - Toledo Navy & Royal Blue */
  --color-brand-primary: #0F172A; /* Deep Slate Navy */
  --color-brand-secondary: #1E293B;
  --color-brand-accent: #2563EB; /* Royal Blue */
  --color-brand-accent-hover: #1D4ED8;
  --color-brand-accent-light: #EFF6FF;
  --color-brand-accent-glow: rgba(37, 99, 235, 0.15);

  /* Functional Status Colors */
  --color-success: #10B981;
  --color-success-bg: #ECFDF5;
  --color-success-text: #065F46;
  --color-warning: #F59E0B;
  --color-warning-bg: #FFFBEB;
  --color-warning-text: #92400E;
  --color-danger: #EF4444;
  --color-danger-bg: #FEF2F2;
  --color-danger-text: #991B1B;
  --color-info: #0284C7;
  --color-info-bg: #F0F9FF;
  --color-info-text: #075985;

  /* Surfaces & Backgrounds */
  --bg-app: #F8FAFC;
  --bg-surface: #FFFFFF;
  --bg-surface-subtle: #F1F5F9;
  --bg-sidebar: #0B132B;
  --bg-sidebar-hover: #1C2541;
  --bg-sidebar-active: #3A506B;

  /* Text & Typography */
  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #94A3B8;
  --text-inverse: #FFFFFF;
  --text-inverse-muted: #CBD5E1;

  /* Borders & Dividers */
  --border-color: #E2E8F0;
  --border-subtle: #F1F5F9;
  --border-focus: #2563EB;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --radius-full: 9999px;

  /* Typography Settings */
  --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-family-heading: 'Outfit', 'Inter', sans-serif;

  /* Layout Dimensions */
  --sidebar-width: 260px;
  --navbar-height: 68px;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family-base);
  background-color: var(--bg-app);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family-heading);
  color: var(--text-primary);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.015em;
}

h1 { font-size: 1.875rem; font-weight: 700; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.125rem; }
h5 { font-size: 1rem; }

p {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

a {
  color: var(--color-brand-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-brand-accent-hover);
}

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* Utility Classes */
.text-muted { color: var(--text-muted) !important; }
.text-secondary { color: var(--text-secondary) !important; }
.text-primary { color: var(--text-primary) !important; }
.text-success { color: var(--color-success) !important; }
.text-warning { color: var(--color-warning) !important; }
.text-danger { color: var(--color-danger) !important; }

.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.flex { display: flex; }
.flex-col { display: flex; flex-direction: column; }
.items-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; }
.gap-6 { gap: 1.5rem; }

.w-full { width: 100%; }
.hidden { display: none !important; }