* {
    box-sizing: border-box;
}

body {
    margin: 0px;
    height: 100vh;
    width: 100vw;
    font-weight: 700;
    font-family: Arial, Helvetica, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    color: #555;
    background-color: #f6f6f6;
}

#back-btn {
    /* display: none; Hidden by default */
    position: fixed;
    /* Fixed/sticky position */
    top: 30px;
    /* Place the button at the bottom of the page */
    left: 0px;
    /* Place the button 30px from the right */
    z-index: 99;
    /* Make sure it does not overlap */
    border: none;
    /* Remove borders */
    outline: none;
    /* Remove outline */
    background-color: #b9bdc0;
    /* Set a background color */
    color: black;
    /* Text color */
    cursor: pointer;
    /* Add a mouse pointer on hover */
    padding: 15px;
    /* Some padding */
    border-radius: 0px 20px 20px 0px;
    /* Rounded corners */
    font-size: 18px;
    /* Increase font size */
    font-weight: bold;
    vertical-align: middle;
    vertical-align: center;
}

#back-btn:hover {
    background-color: #aca6a6;
    /* Add a dark-grey background on hover */
}

#back-btn img {
    vertical-align: middle;
}

#back-btn p {
    display: inline;
    vertical-align: middle;
}

.login-div {
    width: 430px;
    height: 600px;
    background-color: #ecf0f3;
    padding: 60px 35px 35px 35px;
    border-radius: 40px;
    box-shadow: 13px 13px 20px #cbced1, -13px -13px 20px #ffffff;
}

.logo {
    background: url(./img/logo/zarinpal.png);
    background-repeat: no-repeat;
    background-size: cover;
    width: 100px;
    height: 100px;
    border-radius: 50%;
    margin: 0 auto;
    box-shadow: 0px 0px 2px #5f5f5f, 0px 0px 0px 5px #ecf0f3, 8px 8px 15px #afaaa7, -8px -8px 15px #ffffff;
}

.title {
    text-align: center;
    font-size: 28px;
    padding-top: 24px;
}

.fields {
    width: 100%;
    padding: 75px 5px 5px 5px;
}

.fields input {
    border: none;
    background: none;
    font-size: 18px;
    padding: 20px 10px 20px 5px;
    outline: none;
}

.username,
.password {
    margin-bottom: 30px;
    border-radius: 25px;
    box-shadow: 8px 8px 8px #cbced1, -8px -8px 8px #ffffff;
}

.svg-icon {
    height: 22px;
    margin: 0px 10px -4px 25px;
}

.login-btn {
    border: none;
    cursor: pointer;
    width: 100%;
    height: 60px;
    background-color: #02c8db;
    border-radius: 30px;
    font-size: 20px;
    font-weight: 700;
    color: #ffffff;
    box-shadow: 3px 3px 8px #b1b1b1, 3px -3px -3px 8px #fff;
    transition: all 0.1s linear;
}

.login-btn:hover {
    background-color: #50e5b9;
    font-size: 19px;
}

.link {
    padding-top: 20px;
    text-align: center;
}

.link a {
    text-decoration: none;
    color: #aaa;
    font-size: 15px;
}
.link a:active {
    text-decoration: underline;
    color: blue;
}

@media (max-width:480px) {
    body {
        height: 90vh;
    }

    .login-div {
        width: 280px;
        height: 400px;
        padding: 30px 15px 15px 15px;
    }

    .logo {
        width: 50px;
        height: 50px;
        background-position: center;
        background-size: contain;
    }

    .title {
        padding-top: 12px;
    }

    .fields {
        padding: 40px 0px 0px 0px;
    }

    .fields input {
        font-size: 10px;
        padding: 10px 5px 10px 5px;
        margin: 5px;
    }

    .svg-icon {
        height: 18px;
    }

    .login-btn {
        font-size: 10px;
        height: 30px;
    }

    .login-btn:hover {
        font-size: 9px;
    }

    .link {
        font-size: 10px;
    }

    .link a {
        padding-top: 10px;
        font-size: 10px;
    }
}