Hi there,
Please try this code in the Global CSS:
select, textarea, input[type="text"], input[type="username"], input[type="password"], input[type="Your Name"], input[type="account email"], input[type="Payment Email"], input[type="email"], input[type="enter the text of the captcha"], input[type="number"], input[type="email"], input[type="url"], input[type="search"], input[type="tel"], input[type="color"], .uneditable-input {
    line-height: normal;
    min-height: 30px;
    padding: 7px 15px;
    margin: 0!important;
    box-shadow: none!important;
    -webkit-box-shadow: none!important;
    -moz-box-shadow: none!important;
    -o-box-shadow: none!important;
    background-color: #ffffff !important;
    border: 1px solid #c7c7c7;
    border-color: #c7c7c7;
    border-radius: 50px !important;
    -webkit-border-radius: 50px !important;
    -moz-border-radius: 50px !important;
    -o-border-radius: 50px !important;
    color: #242424;
    font-family: Helvetica, sans-serif, 'Trebuchet MS';
    font-size: 14px;
    font-weight: normal;
    font-style: normal;
    text-decoration: none;
    height: 33px;
}
label {
    font-weight: bold;
    color: #919191;
    font-family: Helvetica, sans-serif, 'Trebuchet MS';
    font-size: 16px;
    cursor: pointer;
    margin: 0px !important;
    line-height: 28px;
    font-weight: normal;
    font-style: normal;
    text-decoration: none;
}
As for the button, you can set it’s styling in X > Theme Options > Buttons.
Hope this helps.