.kotaru-login-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid rgba(21, 214, 255, 0.48);
  border-radius: 8px;
  background: linear-gradient(135deg, #06141c 0%, #0d2633 100%);
  color: #eefbff;
  font: 700 14px/1 "Rajdhani", system-ui, sans-serif;
  letter-spacing: 0;
  cursor: pointer;
  box-shadow: 0 10px 26px rgba(21, 214, 255, 0.16);
  transition: transform 160ms ease, border-color 160ms ease, box-shadow 160ms ease;
}

.kotaru-login-btn::before {
  content: "";
  width: 12px;
  height: 12px;
  border-radius: 999px;
  background: #15d6ff;
  box-shadow: 0 0 16px rgba(21, 214, 255, 0.85);
}

.kotaru-login-btn:hover {
  transform: translateY(-1px);
  border-color: rgba(21, 214, 255, 0.9);
  box-shadow: 0 14px 32px rgba(21, 214, 255, 0.24);
}

.kotaru-login-btn:focus-visible {
  outline: 2px solid #15d6ff;
  outline-offset: 3px;
}

.kotaru-login-btn:active {
  transform: translateY(0);
}