/**
 * BrandSlot — Phase 17 seam component for the login page brand area.
 *
 * Phase 19 ships a minimal shippable placeholder: a 48px circle with "FS"
 * initials, the app name "FamilySync", and the tagline "Family calendar & lists".
 *
 * Phase 17 replaces the internals of this component (swap the placeholder div for
 * an <img> with a real logo) without touching LoginPage's layout. This isolates
 * the branding seam — see 19-UI-SPEC.md §Brand Slot section.
 *
 * CSS custom properties used (all set in tokens.css with placeholder defaults;
 * Phase 17 overrides these values):
 *   --brand-logo-bg           — logo circle background (default: var(--color-member-0))
 *   --brand-logo-text         — initials color (default: #ffffff)
 *   --brand-logo-size         — circle diameter (default: 48px)
 *   --brand-logo-border-radius — circle shape (default: 50%)
 *
 * Accessibility:
 *   <h1> contains the app name — screen readers read "FamilySync" as the page title.
 *   The logo circle is aria-hidden (the text is the accessible label).
 *   No <img> today → no broken image ref → no layout shift when Phase 17 replaces it.
 *
 * Security: all copy is plain-text JSX children — no dangerouslySetInnerHTML (T-05-24).
 */

export function BrandSlot() {
  return (
    <div style={{ textAlign: 'center' }}>
      {/* Phase 17 replaces this div with <img src="..." alt="" /> */}
      <div
        aria-hidden="true"
        style={{
          width: 'var(--brand-logo-size, 48px)',
          height: 'var(--brand-logo-size, 48px)',
          borderRadius: 'var(--brand-logo-border-radius, 50%)',
          background: 'var(--brand-logo-bg, var(--color-member-0, #4a90d9))',
          color: 'var(--brand-logo-text, #ffffff)',
          display: 'flex',
          alignItems: 'center',
          justifyContent: 'center',
          margin: '0 auto var(--space-2, 8px)',
          fontSize: 'var(--text-display-size, 24px)',
          fontWeight: 600,
          fontFamily: 'var(--font-family-base)',
          flexShrink: 0,
          aspectRatio: '1 / 1',
        }}
      >
        FS
      </div>

      {/* App name — <h1> so screen readers identify the page (UI-SPEC §Accessibility) */}
      <h1
        style={{
          margin: 0,
          marginTop: 'var(--space-2, 8px)',
          marginBottom: 'var(--space-1, 4px)',
          fontSize: 'var(--text-display-size, 24px)',
          fontWeight: 600,
          lineHeight: 'var(--text-display-line-height, 1.2)',
          color: 'var(--color-text-primary, #111318)',
          fontFamily: 'var(--font-family-base)',
        }}
      >
        FamilySync
      </h1>

      {/* Tagline */}
      <p
        style={{
          margin: 0,
          marginBottom: 'var(--space-8, 32px)',
          fontSize: 'var(--text-body-size, 15px)',
          fontWeight: 400,
          lineHeight: 'var(--text-body-line-height, 1.5)',
          color: 'var(--color-text-secondary, #6b7280)',
          fontFamily: 'var(--font-family-base)',
        }}
      >
        Family calendar &amp; lists
      </p>
    </div>
  );
}
