/**
 * Main styles for Word Pair Matching Game
 * Global styles, CSS variables, and base resets
 */

/* ===== CSS Variables ===== */
:root {
  /* Colors */
  --color-bg: #f9fafb;
  --color-text: #111827;
  --color-text-light: #6b7280;
  --color-border: #e5e7eb;

  /* Category colors */
  --color-category-1: #ef4444;
  --color-category-2: #3b82f6;
  --color-category-3: #10b981;
  --color-category-4: #f59e0b;
  --color-category-5: #8b5cf6;
  --color-category-6: #ec4899;

  /* Button states */
  --color-selected: #3b82f6;
  --color-selected-bg: rgba(59, 130, 246, 0.1);
  --color-merged-bg: #f3f4f6;
  --color-button-bg: #ffffff;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 0.75rem;
  --spacing-lg: 1rem;
  --spacing-xl: 1.5rem;
  --spacing-2xl: 2rem;

  /* Animation timing */
  --duration-shake: 300ms;
  --duration-merge: 500ms;
  --duration-transition: 200ms;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas,
    'Courier New', monospace;
}

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

html {
  height: 100%;
}

body {
  min-height: 100%;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.5;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* ===== Layout ===== */
#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-lg);
}

/* ===== Typography ===== */
h1 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--spacing-xl);
  color: var(--color-text);
}

h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
}

p {
  margin-bottom: var(--spacing-md);
}

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

.text-center {
  text-align: center;
}

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }