/**
 * Focus Styles - WCAG 2.4.7 Compliant
 * DEF-004: Keyboard Navigation Enhancement
 * Provides consistent, visible focus indicators across all calculators
 */

/* Base focus outline - high contrast */
:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 2px;
}

/* Remove default focus for mouse users */
:focus:not(:focus-visible) {
  outline: none;
}

/* Form controls */
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 0;
  border-color: #0d6efd;
  box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.25);
}

/* Buttons */
button:focus-visible,
.btn:focus-visible,
[role="button"]:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 2px;
  box-shadow: 0 0 0 4px rgba(13, 110, 253, 0.25);
}

/* Links */
a:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 2px;
  border-radius: 2px;
}

/* Toggle buttons (special case) */
.toggle-btn:focus-visible,
.btn-toggle:focus-visible,
#toggleAmortization:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 2px;
  z-index: 1; /* Ensure outline visible above siblings */
}

/* Share button focus */
.share-btn:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 2px;
  box-shadow: 0 0 0 4px rgba(13, 110, 253, 0.25);
}

/* Results section when focused */
.results:focus-visible,
[data-results]:focus-visible,
#results:focus-visible {
  outline: 3px solid #198754; /* Green for results */
  outline-offset: 4px;
  border-radius: 8px;
}

/* Skip link styles */
.skip-link {
  position: absolute;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  background: #212529;
  color: #fff;
  padding: 12px 24px;
  border-radius: 0 0 8px 8px;
  text-decoration: none;
  font-weight: 500;
  z-index: 9999;
  transition: top 0.2s ease;
}

.skip-link:focus,
.skip-link.visible {
  top: 0;
}

.skip-link:focus-visible {
  outline: 3px solid #ffc107;
  outline-offset: 2px;
}

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

/* ARIA live region */
#aria-live-announce {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Card focus states */
.info-card:focus-visible,
.summary-card:focus-visible,
.breakdown-item:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 4px;
  border-radius: 8px;
}

/* Chart canvas focus */
canvas:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 4px;
  border-radius: 4px;
}

/* Calculator form focus */
#calculator-form:focus-visible,
.calculator:focus-visible,
.input-section:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 4px;
  border-radius: 8px;
}

/* Navigation links */
nav a:focus-visible,
.nav-link:focus-visible {
  outline: 3px solid #0d6efd;
  outline-offset: 2px;
  border-radius: 4px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :focus-visible {
    outline: 3px solid currentColor;
    outline-offset: 2px;
  }

  button:focus-visible,
  input:focus-visible {
    outline-width: 4px;
  }

  .skip-link:focus-visible {
    outline: 4px solid currentColor;
  }
}

/* Reduced motion - no focus animations */
@media (prefers-reduced-motion: reduce) {
  .skip-link {
    transition: none;
  }

  :focus-visible {
    transition: none;
  }
}