body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    padding: 0;
    background-image: url(image.jpg);
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center;
}
#box {
    width: 400px;
    font-family:Verdana, Geneva, Tahoma, sans-serif;
    background-color: #2c3e50;
    padding: 15px;
    border-radius: 25px;
    border: 2px solid antiquewhite;
}
#box h1 {
    text-align: center;
    letter-spacing: 4px;
    color:antiquewhite;
    font-weight: 300;
}

input:not([type="submit"]) {
    width: 100%;
    padding: 10px 45px;
    box-sizing: border-box;
    border: 2px solid #bbb;
    outline: none;
    border-radius: 6px;
}
input:not([type="submit"]):focus {
    border-color: #1abc9c;
    box-shadow: 0 0 8px #1abc9c;
}
input:not([type="submit"]):focus+i {
    background-color:#1abc9c;
}

input[type="submit"] {
    width: 100%;
    padding: 20px;
    background-color: brown;
    color: antiquewhite;
    border: none;
    font-size: 21px;
    letter-spacing: 2px;
    font-weight: bold;
    border-radius: 8px;
    cursor: pointer;
    margin-top: 20px;
}
input[type="submit"]:hover {
    background-color: chocolate;
}

.champ {
    position: relative;
    margin: 10px 0;
}
.champ i {
    position: absolute;
    top: 0;
    left: 0;
    font-size: 20px;
    color:#fff;
    width: 40px;
    height: 100%;
    background-color: #bbb;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 6px 0 0 6px;
}