body,
html {
    height: 100%;
    margin: 0;
    background-color: #979797;
    /* blue background */
    font-family: "Segoe UI", Tahoma, sans-serif;
}

/* Center the login form */
.container {
    height: 100vh;
    display: flex;
    justify-content: center;
    /* horizontal center */
    align-items: center;
    /* vertical center */
}

/* Style for the login window */
#login_window {
    background: #ffffff;
    padding: 40px 50px;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    text-align: center;

    width: 100%;
    max-width: 500px;
}

/* Header */
#login_window h1 {
    font-weight: 700;
    color: #616161;
    margin-bottom: 25px;
}

/* Inputs */
#login_window input {
    margin-bottom: 15px;
}

/* Button */
#btn_login {
    width: 100%;
    padding: 10px;
    font-weight: 600;
}