/* ═══════════════════════════════════════════════════════════════
   base.css — Reset, Typography, Base Utilities
   Bird City Network — Seguimiento y Control
   ═══════════════════════════════════════════════════════════════ */

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

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

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

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

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

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

img { max-width: 100%; height: auto; }

ul, ol { margin-bottom: var(--space-4); padding-left: var(--space-5); }

/* ── Accessibility Utilities ── */

/* sr-only (WCAG) — visually hidden but accessible to screen readers */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* Skip-to-content link (WCAG 2.4.1) */
.skip-to-content {
  position: absolute;
  top: -100px;
  left: 0;
  z-index: var(--z-skip-link);
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-primary);
  color: #fff;
  border-radius: 0 0 var(--radius-md) 0;
  font-weight: var(--font-weight-semibold);
}

.skip-to-content:focus {
  top: 0;
  outline: var(--focus-ring-width) solid var(--color-accent);
  outline-offset: var(--focus-ring-offset);
}

/* Focus-visible (WCAG 2.4.7) — keyboard navigation */
*:focus {
  outline: none;
}

*:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
  border-radius: var(--radius-sm);
}

/* Reduced motion (WCAG 2.3.3) */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ── Scrollbar styling ── */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-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-muted); }

/* ── Loading spinner (accessible) ── */
.sc-spinner {
  display: inline-block;
  width: 1.5rem;
  height: 1.5rem;
  border: 3px solid var(--color-primary-lightest);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: sc-spin 0.8s linear infinite;
}

@keyframes sc-spin {
  to { transform: rotate(360deg); }
}

.spinner-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.8);
  z-index: var(--z-modal);
}

/* ── Transition helpers ── */
.fade-in {
  animation: fadeIn var(--transition-base) ease forwards;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ── Text utilities ── */
.text-primary { color: var(--color-primary) !important; }
.text-accent { color: var(--color-accent) !important; }
.text-muted { color: var(--color-muted) !important; }
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.font-weight-bold { font-weight: var(--font-weight-bold) !important; }
.font-weight-semibold { font-weight: var(--font-weight-semibold) !important; }

/* ── Spacing utilities ── */
.mt-0 { margin-top: var(--space-0) !important; }
.mt-1 { margin-top: var(--space-1) !important; }
.mt-2 { margin-top: var(--space-2) !important; }
.mt-3 { margin-top: var(--space-3) !important; }
.mt-4 { margin-top: var(--space-4) !important; }
.mt-5 { margin-top: var(--space-5) !important; }
.mb-0 { margin-bottom: var(--space-0) !important; }
.mb-2 { margin-bottom: var(--space-2) !important; }
.mb-3 { margin-bottom: var(--space-3) !important; }
.mb-4 { margin-bottom: var(--space-4) !important; }
.mb-5 { margin-bottom: var(--space-5) !important; }
.p-0 { padding: var(--space-0) !important; }
.p-2 { padding: var(--space-2) !important; }
.p-3 { padding: var(--space-3) !important; }
.p-4 { padding: var(--space-4) !important; }
.p-5 { padding: var(--space-5) !important; }
.px-4 { padding-left: var(--space-4) !important; padding-right: var(--space-4) !important; }
.py-4 { padding-top: var(--space-4) !important; padding-bottom: var(--space-4) !important; }
.py-5 { padding-top: var(--space-5) !important; padding-bottom: var(--space-5) !important; }
.py-8 { padding-top: var(--space-8) !important; padding-bottom: var(--space-8) !important; }