Checkout Stepper Summary Rail

<div class="nuda-st2-checkout-rail">
  <ol class="nuda-st2-checkout-rail__steps">
    <li class="is-done">Cart</li>
    <li class="is-active" aria-current="step">Shipping</li>
    <li>Payment</li>
  </ol>
  <div class="nuda-st2-checkout-rail__bar">
    <span style="transform: scaleX(0.5)"></span>
  </div>
  <div class="nuda-st2-checkout-rail__summary">
    <span>Order total</span>
    <strong>$84.00</strong>
  </div>
</div>

.nuda-st2-checkout-rail {
  width: 100%;
  max-width: 300px;
  background: rgba(255,255,255,.02);
  border: 1px solid rgba(255,255,255,.07);
  border-radius: 14px;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.nuda-st2-checkout-rail__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: #63636e;
}

.nuda-st2-checkout-rail__steps li.is-done {
  color: #a0a0a8;
}

.nuda-st2-checkout-rail__steps li.is-active {
  color: #e4ff54;
  font-weight: 600;
}

.nuda-st2-checkout-rail__bar {
  position: relative;
  height: 4px;
  background: rgba(255,255,255,.07);
  border-radius: 99px;
  overflow: hidden;
}

.nuda-st2-checkout-rail__bar span {
  position: absolute;
  inset: 0;
  background: #e4ff54;
  border-radius: 99px;
  transform-origin: left;
  transition: transform .6s cubic-bezier(.16,1,.3,1);
}

.nuda-st2-checkout-rail__summary {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding-top: 8px;
  border-top: 1px solid rgba(255,255,255,.06);
  font-size: 11px;
  color: #a0a0a8;
}

.nuda-st2-checkout-rail__summary strong {
  color: #fafafa;
  font-size: 14px;
}

@media (prefers-reduced-motion:reduce) {
  .nuda-st2-checkout-rail__bar span {
    transition: none;
  }
}