style.css

.Select select {
    width: 100%;
    -webkit-appearance: none;
    -moz-appearance: none;
    background: transparent;
    background-image: url("data:image/svg+xml;utf8,<svg fill='black' height='24' viewBox='0 0 24 24' width='50' xmlns='http://www.w3.org/2000/svg'><path d='M7 10l5 5 5-5z'/><path d='M0 0h24v24H0z' fill='none'/></svg>");
    background-repeat: no-repeat;
    background-position-x: 100%;
    background-position-y: 5px;
    border: none; border:1px solid #aaa;
    border-radius: 4px; font-size: 14px;
    padding: 10px 0px; text-indent: 15px;
    outline: none;
  }
.Select{ padding: 20px;}
.Select select:after{ height: 10px; width: 10px; background: red; content: ""; display: block;}
.Select select:focus,.Select select:hover{ box-shadow: 0px 0px 0px 2px rgba(0,0,0,0.1);}