Edit in JSFiddle

<section class="contact">
        <div class="container">
            <div class="contact-wrap">
                <h2>Get in Touch</h2>
                <form action="" class="contact-form">
                    <div class="form-group">
                        <input type="email" placeholder="Your Ymail" class="form-control">
                    </div>
                    <!-- /.form-group -->
                    <div class="form-group">
                        <input type="text" placeholder="Subject" class="form-control">
                    </div>
                    <!-- /.form-group -->
                    <div class="form-group w-100">
                        <textarea name="" id="" placeholder="Your Message" class="form-control"></textarea>
                    </div>
                    <!-- /.form-group -->
                    <div class="submit-btn-wrap">
                        <input type="submit" name="submit" value="send message" class="button button-radius">
                    </div>
                    <!-- /.submit-button -->
                </form>
                <!-- /.contact-form -->
            </div>
            <!-- /.contact-wrap -->
        </div>
        <!-- /.container -->
    </section>
    <!-- /.contact -->
/* contact form input */



.contact{
  padding: 90px 0 100px;
}


.contact-form {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    margin: 0 -15px;
}

.contact-wrap h2{
  font-size: 45px;
  margin-top: 0;
  margin-bottom: 20px;
  color: #314584;
  
}

.form-group {
    width: 100%;
    max-width: 50%;
    padding: 0 15px;
    box-sizing: border-box;
    margin-top: 30px;
}

.form-group textarea {
    height: 120px;
    color: #314584;
}

.form-control {
    width: 100%;
    height: 60px;
    background-color: #f4fafe;
    border: 1px solid #314584;
    text-indent: 15px;
    font-weight: 600;
    font-size: 18px;
}

.form-group textarea {
    width: 100%;
    padding-top: 10px;
}

.form-group input:focus {
    outline: none;
}

.form-group textarea:focus {
    outline: none;
}

.form-group input::placeholder {
    /* Firefox, Chrome, Opera */
    color: #314584;
    font-weight: 600;
    letter-spacing: 1px;
}

.form-group input:-ms-input-placeholder {
    /* Internet Explorer 10-11 */
    color: #314584;
    font-weight: 600;
    letter-spacing: 1px;
}

.form-group input::-ms-input-placeholder {
    /* Microsoft Edge */
    color: #314584;
    font-weight: 600;
    letter-spacing: 1px;
}

.form-group textarea::placeholder {
    /* Firefox, Chrome, Opera */
    color: #314584;
    letter-spacing: 1px;
}

.form-group textarea:-ms-input-placeholder {
    /* Internet Explorer 10-11 */
    color: #314584;
    letter-spacing: 1px;
}

.form-group textarea::-ms-input-placeholder {
    /* Microsoft Edge */
    color: #314584;
    letter-spacing: 1px;
}

.submit-btn-wrap {
    width: 100%;
    text-align: center;
    margin-top: 30px;
}

.submit-btn-wrap input {
    border: 0;
}
.w-100{
 width: 100%;
 max-width: 100%
}


.submit-btn-wrap input{
    display: inline-block;
    padding: 18px 35px;
    font-weight: 600;
    color: #fff;
    background-color: #ff3946;
    text-transform: capitalize;
    transition: all .5s ease;
    font-size: 18px;
    border-radius: 30px;
}

.submit-btn-wrap input:hover {
    background-color: #314584;
}