.lc-toggle-btn {
    position: fixed;
    z-index: 2147483000;
    padding: 10px 14px;
    border-radius: 999px;
    font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
    font-weight: 600;
    cursor: pointer;
    user-select: none;
    border: 1px solid rgba(255,255,255,0.14);
    box-shadow: 0 8px 20px rgba(0,0,0,0.35);
    transition: transform .12s ease, box-shadow .2s ease, opacity .2s ease;
    animation: lcPulse 2.2s ease-in-out 2;
}
.lc-toggle-btn:hover { transform: translateY(-1px); box-shadow: 0 10px 24px rgba(0,0,0,0.4); }
.lc-toggle-btn:active { transform: translateY(0); }
.lc-theme-dark { background: #111; color: #f5f5f5; }
.lc-theme-light { background: #fff; color: #111; border-color: rgba(0,0,0,0.15); }

@keyframes lcPulse {
  0% { box-shadow: 0 0 0 0 rgba(255,255,255,0.18); }
  70% { box-shadow: 0 0 0 12px rgba(255,255,255,0); }
  100% { box-shadow: 0 0 0 0 rgba(255,255,255,0); }
}