style.css

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body{
    background-color: #0581ca;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.box{
    background-color: #fff;
    padding-top: 30px;
    padding: 30px;
}

.box h1{
    margin-bottom: 40px;
    text-align: center;
    font-size: 28px;
    color: #015a96;
}

input{
    user-select: none;
    width: 400px;
    height: 50px;
    padding: 20px;
    border-radius: 6px;
    border: 2px solid rgb(13, 152, 245);
    outline: none;
    font-size: 22px;
}

input::placeholder{
    font-size: 23px;
}
.btn1{
    margin-right: 30px;
    margin-left: 25px;
}

#button{
    width: 155px;
    height: 50px;
    font-family: 'Segoe UI', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    font-weight: 700;
    font-size: 20px;
    margin-top: 20px;
    border: 2px solid rgb(20,139,250);
    text-align: center;
    color: #fff;
    display: flex;
    border-radius: 7px;
    background-color: #0c81ee;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: 0.25s;
}

#button:hover{
    color: #0c81ee;
    background-color: #fff;
}