<div class="otp-container">
  <h3>Enter Verification Code</h3>
  <div class="otp-inputs">
    <input type="text" maxlength="1" class="otp-field" autofocus>
    <input type="text" maxlength="1" class="otp-field">
    <input type="text" maxlength="1" class="otp-field">
    <input type="text" maxlength="1" class="otp-field">
  </div>
</div>

.otp-container {
  font-family: system-ui, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  text-align: center;
  background: #fff;
  padding: 30px;
  border-radius: 16px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.05);
  max-width: 350px;
}
.otp-container h3 {
  margin: 0 0 20px 0;
  color: #1f2937;
}
.otp-inputs {
  display: flex;
  gap: 10px;
  justify-content: center;
}
.otp-field {
  width: 50px;
  height: 60px;
  font-size: 1.5rem;
  text-align: center;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  outline: none;
  transition: border-color 0.2s;
  font-weight: 600;
  color: #1f2937;
}
.otp-field:focus {
  border-color: #3b82f6;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

const inputs = document.querySelectorAll(".otp-field");

inputs.forEach((input, index) => {
  // Handle Typing
  input.addEventListener("keyup", (e) => {
    if (e.key >= 0 && e.key <= 9) {
      if (index < inputs.length - 1) inputs[index + 1].focus();
    } else if (e.key === "Backspace") {
      if (index > 0) inputs[index - 1].focus();
    }
  });

  // Handle Paste
  input.addEventListener("paste", (e) => {
    e.preventDefault();
    const data = e.clipboardData.getData("text");
    if (!/^\d+$/.test(data)) return;
    const digits = data.split("");
    inputs.forEach((inp, i) => {
      if (i >= index && digits.length > 0) {
        inp.value = digits.shift();
        inp.focus();
      }
    });
  });
});