*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI';
}

html, body{
    width: 100%;
    height: 100%;
}

body{
    background-color: #262a2f;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.container{
    width: 400px;
    padding: 25px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,0,0,0.1);
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
} 

.container h1{
    font-size: 25px;
    font-weight: 600;
    margin-top: -10px;
    margin-bottom: 7px;
}

.container input{
    width: 100%;
    height: 40px;
    padding: 10px;
    border: 1px solid #494eea;
    border-radius: 5px;
    font-size: 15px;
    font-weight: 400;
}

.container button{
    width: 100%;
    height: 45px;
    background-color: #494eea;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-weight: 600;
    font-size: 18px;
    transition: background-color 0.3s;
}

.container button:hover{
    background-color: #373cd6;
}

.container #downloadBtn{
    display: none;
    margin-top: 7px;
}

#imgBox{
    width: 60%;
    max-height: 0;
    overflow: hidden;
    transition: 0.5s ease;
    border-radius: 5px;
    margin: 10px auto;
}

#imgBox.show-img{
    max-height: 300px;
    border: 1px solid #ccc;
}

#imgBox img{
    width: 100%;
    padding: 7px;
}

.error{
    animation: shake 0.1s linear 5;
    border-color: red !important;
}

@keyframes shake{
    0%{
        transform: translateX(0);
    }
    25%{
        transform: translateX(-2px);
    }
    50%{
        transform: translateX(2px);
    }
    75%{
        transform: translateX(-2px);
    }
    100%{
        transform: translateX(0);
    }
}

/* Mobile-friendly */
@media (max-width: 480px){
    .container{
        width: 85vw;
        padding: 5vw;
    }

    .container h1{
        font-size: 6vw;
        font-weight: 600;
        margin-top: -0.5vw;
        margin-bottom: 1.5vw;
    }

    .container input{
        height: 10vw;
        padding: 1vw 2vw;
        font-size: 4vw;
        font-weight: 500;
    }

    .container button{
        height: 12vw;
        font-size: 5.3vw;
        font-weight: 600;
    }

    .container #downloadBtn{
        margin-top: 1vw;
    }

    #imgBox{
        width: 75%;
        margin: 2vw auto;
    }

    #imgBox img{
        padding: 1.5vw;
    }
}