/* ============================================
   CRISLYN'S MATH ADVENTURE — Design Tokens & Base
   ============================================ */

/* --- Design Tokens (CSS Custom Properties) --- */
:root {
  /* Primary Palette */
  --color-primary: #6B21A8;
  --color-primary-light: #A855F7;
  --color-primary-lighter: #D8B4FE;
  --color-primary-dark: #4C1D95;

  /* Accent */
  --color-accent: #FACC15;
  --color-accent-dark: #EAB308;
  --color-accent-light: #FEF08A;

  /* Secondary */
  --color-teal: #0D9488;
  --color-teal-light: #5EEAD4;
  --color-coral: #F97316;
  --color-coral-light: #FDBA74;
  --color-pink: #EC4899;
  --color-blue: #3B82F6;

  /* Feedback */
  --color-success: #22C55E;
  --color-success-light: #BBF7D0;
  --color-error: #EF4444;
  --color-error-light: #FECACA;
  --color-warning: #F59E0B;
  --color-warning-light: #FDE68A;

  /* Neutrals */
  --color-bg: #FAF5FF;
  --color-bg-alt: #F3E8FF;
  --color-surface: #FFFFFF;
  --color-surface-hover: #F9F5FF;
  --color-text: #1E1B4B;
  --color-text-light: #6B7280;
  --color-text-inverse: #FFFFFF;
  --color-border: #E9D5FF;
  --color-border-light: #F3E8FF;

  /* Typography */
  --font-heading: 'Fredoka One', cursive;
  --font-body: 'Nunito', sans-serif;
  --font-mono: 'Source Code Pro', monospace;

  --text-xs: 0.875rem;
  --text-sm: 1rem;
  --text-base: 1.125rem;    /* 18px minimum */
  --text-lg: 1.25rem;
  --text-xl: 1.5rem;
  --text-2xl: 1.875rem;
  --text-3xl: 2.25rem;
  --text-4xl: 3rem;

  --line-height: 1.6;
  --line-height-tight: 1.3;

  /* 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;
  --space-16: 64px;

  /* Shape */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(107, 33, 168, 0.08);
  --shadow-md: 0 4px 20px rgba(107, 33, 168, 0.12);
  --shadow-lg: 0 8px 30px rgba(107, 33, 168, 0.18);
  --shadow-xl: 0 12px 40px rgba(107, 33, 168, 0.22);
  --shadow-glow: 0 0 20px rgba(168, 85, 247, 0.4);

  /* Transitions */
  --ease-bounce: cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-smooth: cubic-bezier(0.4, 0, 0.2, 1);
  --duration-fast: 150ms;
  --duration-normal: 300ms;
  --duration-slow: 500ms;

  /* Layout */
  --max-width: 1200px;
  --sidebar-width: 280px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--line-height);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

img, svg, video, canvas {
  display: block;
  max-width: 100%;
}

input, button, textarea, select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

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

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

ul, ol {
  list-style: none;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  line-height: var(--line-height-tight);
  color: var(--color-primary-dark);
}

h1 {
  font-size: var(--text-4xl);
  letter-spacing: -0.02em;
}

h2 {
  font-size: var(--text-3xl);
}

h3 {
  font-size: var(--text-2xl);
}

h4 {
  font-size: var(--text-xl);
}

p {
  margin-bottom: var(--space-4);
}

strong {
  font-weight: 700;
}

/* --- Layout Utilities --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.flex {
  display: flex;
}

.flex-col {
  display: flex;
  flex-direction: column;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.flex-wrap {
  flex-wrap: wrap;
}

.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

.grid {
  display: grid;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
}

/* --- Spacing Utilities --- */
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }

/* --- Text Utilities --- */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-sm { font-size: var(--text-sm); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }
.text-muted { color: var(--color-text-light); }
.text-success { color: var(--color-success); }
.text-error { color: var(--color-error); }
.text-accent { color: var(--color-accent-dark); }
.text-primary { color: var(--color-primary); }
.font-heading { font-family: var(--font-heading); }

/* --- Visibility --- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.hidden { display: none !important; }

/* --- Responsive --- */
@media (max-width: 768px) {
  :root {
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
  }

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

  .container {
    padding: 0 var(--space-4);
  }

  .hide-mobile {
    display: none !important;
  }
}

@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

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