Split Digit Phone Input

<!--
  Author: @emma-lake
  License: MIT
  Tags: #buttons #css #interface #opensource #codepeek
-->
<div class="phone-input">
  <span class="phone-input__code">ES +34</span>
  <input type="tel" class="phone-input__field" placeholder="600 123 456"/>
</div>

/*
 * Author: @emma-lake
 * License: MIT
 * Tags: #buttons #css #interface #opensource #codepeek
 */

.phone-input {
  display: flex;
  align-items: stretch;
  width: 250px;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid #2a2a33;
  background: #17171d;
}
.phone-input__code {
  position: relative;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 14px;
  background: #1e1e26;
  color: #cfcfd6;
  font-family: system-ui, sans-serif;
  font-size: 13px;
  font-weight: 600;
  border-right: 1px solid #2a2a33;
  transition: box-shadow 0.3s ease, background 0.3s ease;
}
.phone-input__code::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #60a5fa;
  animation: phone-live-pulse 1.8s ease-in-out infinite;
}
@keyframes phone-live-pulse {
  0%, 100% {
    box-shadow: 0 0 0 0 rgba(96, 165, 250, 0.55);
    opacity: 1;
  }
  50% {
    box-shadow: 0 0 0 5px rgba(96, 165, 250, 0);
    opacity: 0.6;
  }
}
.phone-input:focus-within .phone-input__code {
  background: #24243a;
  box-shadow: inset 0 0 0 1px rgba(96, 165, 250, 0.5);
}
.phone-input__field {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  color: #f1f1f1;
  font-family: system-ui, sans-serif;
  font-size: 14px;
  padding: 12px 14px;
}
.phone-input__field::placeholder {
  color: #6b6b76;
}