Glitch/curved edges form borders/text wrapper issues

Site URL: http://www.sauseofsound.com/contact

I am having an issue where I have styled my contact form and newsletter to be a single line for each field. However, if you look closely there is a little edge that curves up at both the right and left borders of the bottom line. I would like this to go away. I am using 7.1.

here is the code I am using:

.field-list .field-element{
    border-color: none !important;
    border-bottom: solid 1px #615348 !important;
    border-left: none !important;
    border-right: none !important;
    border-top: none !important;
    background-color: transparent !important;
  }
  .field-list select:focus{
    outline-color:  #000000 !important;
  }
  .field-list .section{
    border-color: #000000 !important;}
*:focus {
    outline: none !important;
}

input[type=checkbox]:after{width:15px; height:15px; top:0!important; left:-1px;
position:relative; background-color:#fff; content:''; display:inline-block; visibility:visible;
border:1px solid#50BDB8} input[type=checkbox]:checked:after{width:15px; height:15px;
top:0!important; left:-1px; position:relative; background-color:#50BDB8; content:' ✔ ';
text-align:center; color:#fff; font-size:8px; display:inline-block; visibility:visible;
border:1px solid #50BDB8} .form-wrapper .field-list .field select{bordertop:
none!important; border-left:none!important; border-right:none!important; borderbottom:
1px solid #615348!important; background-color: transparent !important;
color:    #615348!important; color:#615348!important} .form-wrapper .field-list
.section.underline {border-bottom:2px solid #50BDB8!important}

Add to Design > Custom CSS

input.field-element {
    border-radius: 0 !important;
}