/**
 * Aira Antivirus — Modern Resilient CSS Reset
 * Grounded in WCAG 2.1 AA & frontend-ui-engineering standards
 */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  color-scheme: dark;
  overflow-x: hidden;
  width: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

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

body {
  min-height: 100vh;
  min-height: 100dvh;
  width: 100%;
  background-color: var(--surface-canvas);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  font-weight: var(--weight-regular);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  /* Localization resilience: prevent long Russian/English strings from breaking container bounds */
  overflow-wrap: break-word;
}

/* Accessible focus ring baseline (WCAG 2.1 AA compliant) */
:focus {
  outline: none;
}

:focus-visible {
  outline: 2px solid var(--color-accent-400);
  outline-offset: 2px;
}

/* Image & media resilience */
img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
}

/* Form element font inheritance */
input, button, textarea, select {
  font: inherit;
  color: inherit;
}

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

button:disabled, input:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

/* Typography defaults */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  color: var(--text-primary);
  letter-spacing: var(--tracking-tight);
  text-wrap: balance;
}

p {
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  text-wrap: pretty;
}

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

a:hover {
  color: var(--color-accent-300);
}

code, kbd, samp, pre {
  font-family: var(--font-mono);
  font-size: 0.9em;
}

ul, ol {
  list-style: none;
}

/* Accessible Skip Link */
.skip-link {
  position: fixed;
  top: -999px;
  left: var(--space-4);
  z-index: var(--z-skip-link);
  padding: var(--space-3) var(--space-5);
  background: var(--surface-accent-solid);
  color: var(--text-on-accent);
  font-weight: var(--weight-semibold);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
  transition: top var(--transition-fast);
}

.skip-link:focus,
.skip-link:focus-visible {
  top: var(--space-4);
}