.theme-switch {
  position: fixed;
  bottom: 2rem;
  left: 2rem;
  z-index: 1000;
}

.theme-switch input[type="checkbox"] {
  display: none;
}

.theme-switch label {
  display: flex;
  align-items: center;
  cursor: pointer;
  width: 60px;
  height: 32px;
  position: relative;
}

.switch-track {
  width: 100%;
  height: 100%;
  background: var(--bg, #283593);
  border-radius: 16px;
  transition: background 0.3s;
}

.switch-knob {
  position: absolute;
  left: 4px;
  top: 4px;
  width: 24px;
  height: 24px;
  background: var(--primary, #3859a1);
  border-radius: 50%;
  transition: left 0.3s, background 0.3s;
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
}

input[type="checkbox"]:checked + label .switch-track {
  background: var(--bg-light, #fff);
}

input[type="checkbox"]:checked + label .switch-knob {
  left: 32px;
  background: var(--bg-dark, #222);
}