<form class="lf-step" aria-label="Two-step sign in">
  <input type="radio" id="lf-step-1" name="lf-step" class="lf-step-radio" checked />
  <input type="radio" id="lf-step-2" name="lf-step" class="lf-step-radio" />

  <header class="lf-step-head">
    <span class="lf-step-bar" aria-hidden="true"></span>
    <span class="lf-step-counter"><span class="lf-step-now">1</span> of 2</span>
  </header>

  <div class="lf-step-track">
    <fieldset class="lf-step-pane">
      <legend class="lf-step-label">What's your email?</legend>
      <label class="lf-step-row">
        <input
          type="email"
          name="email"
          autocomplete="email"
          placeholder="[email protected]"
          required
        />
      </label>
      <label for="lf-step-2" class="lf-step-btn primary">Next →</label>
    </fieldset>

    <fieldset class="lf-step-pane">
      <legend class="lf-step-label">Now your password</legend>
      <label class="lf-step-row">
        <input
          type="password"
          name="password"
          autocomplete="current-password"
          placeholder="••••••••"
          required
        />
      </label>
      <div class="lf-step-actions">
        <label for="lf-step-1" class="lf-step-btn ghost">← Back</label>
        <button type="submit" class="lf-step-btn primary">Sign in</button>
      </div>
    </fieldset>
  </div>
</form>

.lf-step {
  width: 100%;
  max-width: 320px;
  background: #15151d;
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: 14px;
  padding: 22px 22px;
  display: grid;
  gap: 14px;
  overflow: hidden;
}
.lf-step-radio {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}
.lf-step-head {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 12px;
  font-size: 11px;
  color: #b8b6d4;
}
.lf-step-bar {
  height: 3px;
  border-radius: 99px;
  background: rgba(255, 255, 255, 0.06);
  position: relative;
  overflow: hidden;
}
.lf-step-bar::after {
  content: "";
  position: absolute;
  inset: 0;
  right: 50%;
  background: linear-gradient(90deg, #7c6cff, #ff6c8a);
  border-radius: inherit;
  transition: right 0.4s ease;
}
.lf-step:has(#lf-step-2:checked) .lf-step-bar::after {
  right: 0;
}
.lf-step:has(#lf-step-2:checked) .lf-step-now::after {
  content: "2";
}
.lf-step-now {
  font-weight: 700;
  color: #f0eeff;
}
.lf-step-now::after {
  content: "1";
}
.lf-step-now {
  font-size: 0;
}
.lf-step-now::after {
  font-size: 11px;
}
.lf-step-track {
  display: grid;
  grid-template-columns: 100% 100%;
  width: 100%;
  transition: transform 0.4s cubic-bezier(0.6, 0, 0.2, 1);
}
.lf-step:has(#lf-step-2:checked) .lf-step-track {
  transform: translateX(-100%);
}
.lf-step-pane {
  border: 0;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 12px;
  min-width: 0;
}
.lf-step-label {
  font-size: 13px;
  font-weight: 600;
  color: #f0eeff;
  padding: 0;
}
.lf-step-row input {
  width: 100%;
  box-sizing: border-box;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 13px;
  color: #f0eeff;
  outline: none;
  transition: border-color 0.15s;
}
.lf-step-row input:focus {
  border-color: #7c6cff;
}
.lf-step-actions {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 8px;
}
.lf-step-btn {
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  text-align: center;
  border: 1px solid transparent;
  transition:
    transform 0.12s,
    background 0.15s;
}
.lf-step-btn.primary {
  background: linear-gradient(135deg, #7c6cff, #ff6c8a);
  color: white;
}
.lf-step-btn.primary:hover {
  transform: translateY(-1px);
}
.lf-step-btn.ghost {
  background: transparent;
  color: #b8b6d4;
  border-color: rgba(255, 255, 255, 0.1);
}
.lf-step-btn.ghost:hover {
  color: #f0eeff;
  background: rgba(255, 255, 255, 0.04);
}