index.css

body {
    padding-top: 100px;
}

.navbar {
    height: 57px;
    background-image: linear-gradient(102deg, #374c89, #3c4c89 44%, #713f7f);
    box-shadow: 0 2px 19px 0 rgba(0, 0, 0, 0.07);
}

.navbar-inverse .navbar-brand {
    color: #fff;
}

#auth-form {
    width: 400px;
    margin-left: auto;
    margin-right: auto;
}

.form-group{
    margin-bottom: 20px;
}

.form-horizontal .control-label {
    padding-top: 0px;
    margin-bottom: 5px;
}

.btn {
    width: 200px;
    border-radius: 100px;
    background-color: #4ba8ff;
    box-shadow: 0 2px 7px 0 rgba(0,0,0,.2);
    color: #fff;
    border: none;
    display: block;
    margin-top: 10px;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: 40px;
    padding: 10px;
    padding-left: 16px;
    padding-right: 16px;
    font-size: 16px;
}

.btn:hover {
    background-color: #7ec1ff;
    color: #fff;
}

#add-note-form {
    width: 400px;
    margin-left: auto;
    margin-right: auto;
}

#notes-list {
    width: 500px;
    margin-right: auto;
    margin-left: auto;
}

.note {
    border: solid #e4e4e4 1px;
    box-shadow: 0 2px 7px 0 rgba(0,0,0,.1);
    padding: 20px;
    margin-bottom: 30px;
}