/**
 * ===========================================================================
 * BASE STYLES — AI Agent for Teachers
 * Resets, Defaults, Accessibility & System-wide Rules
 * ===========================================================================
 */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* ===========================================================================
   ACCESSIBILITY & FOCUS STATES
   =========================================================================== */
:focus {
  outline: none;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Universal links */
a {
  color: var(--link);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--link-hover);
  text-decoration: underline;
}

/* Code & pre defaults */
code,
kbd,
samp,
pre {
  font-family: var(--font-mono);
  font-size: 0.92em;
}

/* ===========================================================================
   PREFERS-REDUCED-MOTION
   =========================================================================== */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto !important;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}