:root {
  /* Colors */
  --color-primary: #2563EB;          /* Blue — action buttons, links */
  --color-primary-dark: #1D4ED8;
  --color-primary-light: #DBEAFE;
  --color-accent: #F59E0B;           /* Amber — highlights, badges */
  --color-success: #10B981;          /* Green — correct answers */
  --color-danger: #EF4444;           /* Red — wrong answers, hard */
  --color-warning: #F59E0B;
  
  /* Neutrals */
  --color-bg: #F8FAFC;
  --color-surface: #FFFFFF;
  --color-surface-2: #F1F5F9;
  --color-border: #E2E8F0;
  --color-text: #0F172A;
  --color-text-secondary: #64748B;
  --color-text-muted: #94A3B8;
  
  /* Sidebar */
  --sidebar-bg: #0F172A;
  --sidebar-text: #CBD5E1;
  --sidebar-active: #2563EB;
  --sidebar-width: 240px;
  
  /* Spacing */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --text-xs: 11px;
  --text-sm: 13px;
  --text-base: 15px;
  --text-lg: 17px;
  --text-xl: 20px;
  --text-2xl: 24px;
  --text-3xl: 30px;
  --text-4xl: 36px;
  
  /* 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);
  --shadow-card: 0 0 0 1px rgba(0,0,0,0.04), 0 2px 8px rgba(0,0,0,0.08);
  
  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition: 150ms ease;
}

* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  margin: 0;
  padding: 0;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

html {
  scroll-behavior: smooth;
}

::selection {
  background-color: var(--color-primary-light);
  color: var(--color-primary-dark);
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--color-bg);
}
::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: var(--radius-full);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-muted);
}

/* Button component styles */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  text-decoration: none;
  white-space: nowrap;
}

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

.btn-secondary {
  background-color: var(--color-surface-2);
  color: var(--color-text);
}
.btn-secondary:hover {
  background-color: var(--color-border);
}

.btn-danger {
  background-color: var(--color-danger);
  color: white;
}
.btn-danger:hover {
  background-color: #dc2626;
}

.btn-ghost {
  background-color: transparent;
  color: var(--color-primary);
}
.btn-ghost:hover {
  background-color: var(--color-primary-light);
}

.btn-accent {
  background-color: var(--color-accent);
  color: white;
}
.btn-accent:hover {
  background-color: #d97706;
}

.btn-sm {
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
}
.btn-lg {
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-base);
}

/* Input component styles */
.input {
  padding: var(--space-2) var(--space-3);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  width: 100%;
  background-color: var(--color-surface);
  color: var(--color-text);
  outline: none;
  transition: var(--transition);
  font-family: inherit;
}
.input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

/* Card component */
.card {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: var(--space-6);
}

/* Badge component */
.badge {
  display: inline-flex;
  padding: 2px var(--space-2);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  white-space: nowrap;
}
.badge-blue { background-color: #DBEAFE; color: #1D4ED8; }
.badge-green { background-color: #D1FAE5; color: #065F46; }
.badge-amber { background-color: #FEF3C7; color: #92400E; }
.badge-red { background-color: #FEE2E2; color: #991B1B; }
.badge-gray { background-color: #F1F5F9; color: #475569; }

/* Modal overlay */
.modal-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  backdrop-filter: blur(4px);
}
.modal-box {
  background-color: white;
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  max-width: 480px;
  width: 90%;
  box-shadow: var(--shadow-lg);
  position: relative;
}
.modal-title {
  margin-top: 0;
  font-size: var(--text-xl);
  font-weight: 700;
  margin-bottom: var(--space-4);
}
.modal-body {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-6);
}
.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-3);
}

/* Toast notifications */
.toast-container {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.toast {
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  color: white;
  font-size: var(--text-sm);
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  transform: translateX(120%);
  transition: transform 300ms ease;
  max-width: 320px;
}
.toast.visible {
  transform: translateX(0);
}
.toast-success { background-color: var(--color-success); }
.toast-error { background-color: var(--color-danger); }

/* ... existing styles ... */

/* Prevent text overflow in buttons globally */
button, .btn, a.btn {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Prevent any heading from overflowing */
h1, h2, h3, h4 {
  overflow-wrap: break-word;
  word-break: break-word;
}

/* Prevent cards from overflowing their containers */
.card, .pricing-card, .feature-card, .stat-card {
  min-width: 0;
}

/* Responsive images */
img, svg {
  max-width: 100%;
  height: auto;
}

/* Ensure inputs don't overflow on mobile */
input, textarea, select {
  max-width: 100%;
  box-sizing: border-box;
}