/* ── Lock button (hidden staff login entry point) ── */
.btn-lock {
  position: fixed; top: 20px; left: 20px; z-index: 100;
  width: 44px; height: 44px; border-radius: 50%;
  border: 1px solid rgba(123, 94, 167, 0.5);
  background: rgba(13, 11, 26, 0.7);
  backdrop-filter: blur(10px);
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: border-color 0.2s, background 0.2s, transform 0.15s;
  animation: fadeIn 1s both; animation-delay: 0.8s;
  text-decoration: none;
}
.btn-lock:hover { border-color: rgba(79, 195, 247, 0.7); background: rgba(79, 195, 247, 0.1); transform: scale(1.08); }
.btn-lock:active { transform: scale(0.95); }
.btn-lock svg { width: 18px; height: 18px; stroke: rgba(200, 190, 230, 0.7); fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; transition: stroke 0.2s; }
.btn-lock:hover svg { stroke: #4FC3F7; }
.btn-lock::after {
  content: 'Войти'; position: absolute; left: 54px; top: 50%; transform: translateY(-50%);
  font-family: 'DM Sans', sans-serif; font-size: 12px; color: var(--text-secondary);
  white-space: nowrap; opacity: 0; transition: opacity 0.2s; pointer-events: none;
}
.btn-lock:hover::after { opacity: 1; }