/* ============================================================
   AUTH SCREEN
   ============================================================ */
#authScreen {
  position: fixed; inset: 0; z-index: 2000;
  display: none; align-items: center; justify-content: center;
  background: var(--bg-base); padding: 20px;
}
.auth-card {
  width: 100%; max-width: 400px;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 28px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
}
.auth-logo {
  font-size: 13px; text-transform: uppercase; letter-spacing: 2px; font-weight: 700;
  text-align: center; margin-bottom: 20px; color: var(--text-primary);
}
.auth-tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--border); margin-bottom: 20px; }
.auth-tab {
  flex: 1; padding: 8px; color: var(--text-secondary);
  border-bottom: 2px solid transparent; transition: all 150ms ease; font-weight: 500;
}
.auth-tab:hover { color: var(--text-primary); }
.auth-tab.active { color: var(--text-primary); border-bottom-color: var(--accent-study); }
.auth-title { font-size: 18px; font-weight: 600; text-align: center; margin-bottom: 6px; }
.auth-sub { font-size: 13px; color: var(--text-secondary); text-align: center; margin-bottom: 20px; }
.auth-submit { width: 100%; margin-top: 8px; }
.username-status { font-size: 12px; margin-top: 4px; min-height: 14px; color: var(--text-muted); }
.username-status.ok { color: var(--success); }
.username-status.err { color: var(--danger); }
.auth-error { color: var(--danger); font-size: 13px; min-height: 18px; margin: 6px 0; }
.auth-link {
  display: block; width: 100%; text-align: center; margin-top: 12px;
  color: var(--text-secondary); font-size: 13px; transition: color 150ms ease;
}
.auth-link:hover { color: var(--accent-study); }
/* Inputs de auth: forzar fondo/texto legibles (incl. autocompletado del navegador) */
.auth-input {
  background: var(--bg-input) !important;
  color: var(--text-primary) !important;
  -webkit-text-fill-color: var(--text-primary) !important;
  caret-color: var(--text-primary);
}
.auth-input::placeholder { color: var(--text-muted); -webkit-text-fill-color: var(--text-muted); }
.auth-input:-webkit-autofill,
.auth-input:-webkit-autofill:hover,
.auth-input:-webkit-autofill:focus,
.auth-input:-webkit-autofill:active {
  -webkit-text-fill-color: var(--text-primary) !important;
  -webkit-box-shadow: 0 0 0 1000px var(--bg-input) inset !important;
  box-shadow: 0 0 0 1000px var(--bg-input) inset !important;
  caret-color: var(--text-primary);
  transition: background-color 9999s ease-in-out 0s;
}