style.css

input {
    display: block;
    width: 50%;
    border: none;
    margin: auto;
    border-bottom: 1px solid blue;
    box-sizing: border-box;
    font-size: 24px;
    transition: 0.3s ease;
    -moz-transition: 0.3s ease;
    -webkit-transition: 0.3s ease;
    -o-transition: 0.3s ease;
    -ms-transition: 0.3s ease;
    padding-top: 15px;
    padding-bottom: 5px;
}
::-webkit-input-placeholder {
text-align: center;
}

.form-group {
    margin-top: 20px;
    text-align: center;
}

.button {
    display: inline-block;
    padding: 15px 15px;
    font-size: 24px;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    outline: none;
    color: #fff;
    background-color: teal;
    border: none;
    border-radius: 15px;
    box-shadow: 0 9px rgb(202, 196, 196);
    margin-top: 15px;
}

.button:hover {
    background-color: rgb(135, 135, 212);
}

.button:active {
    background-color: teal;
    box-shadow: 0 5px #666;
    transform: translateY(4px);
}