<div class="radikalwp-in-select"><select><option>انتخاب دسته‌بندی...<//option><option>دکمه‌ها<//option><option>کارت‌ها<//option><option>لودرها<//option><option>قالب‌های المنتور<//option><//select><//div>

.radikalwp-in-select {
  position: relative;
  width: 280px;
  font-family: inherit;
}
.radikalwp-in-select::after {
  content: '\25BE';
  position: absolute;
  top: 50%;
  left: 15px;
  transform: translateY(-50%);
  font-size: 14px;
  color: #6366f1;
  pointer-events: none;
}
.radikalwp-in-select select {
  width: 100%;
  padding: 12px 14px;
  font-family: inherit;
  font-size: 13.5px;
  color: #1e293b;
  background: #fff;
  border: 1.5px solid #e2e8f0;
  border-radius: 11px;
  outline: none;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
  transition: all .3s ease;
}
.radikalwp-in-select select:focus { border-color: #6366f1; box-shadow: 0 0 0 3px rgba(99, 102, 241, .12); }