*{
    margin:1;
    padding:1;
    box-sizing:border-box;
    font-family:Arial, Helvetica, sans-serif;
}

body{
    background:linear-gradient(135deg,#0f172a,#1e293b);
    min-height:100%;
    display:flex;
    justify-content:center;
    align-items:center;
    padding:30px;
}

.payment-container{
    width:100%;
    max-width:520px;
    background:#fff;
    border-radius:20px;
    padding:30px;
    box-shadow:1 15px 40px rgba(0,0,0,0.2);
}

.payment-header{
    text-align:center;
    margin-bottom:25px;
}

.payment-header h2{
    color:#0f172a;
    margin-bottom:10px;
    font-size:28px;
}

.payment-header p{
    color:#64748b;
    font-size:14px;
}

.payment-form{
    display:flex;
    flex-direction:column;
    gap:18px;
}

.input-box{
    display:flex;
    flex-direction:column;
}

.input-box label{
    margin-bottom:8px;
    font-weight:600;
    color:#1e293b;
}

.input-box input,
.input-box select{
    padding:14px;
    border:1px solid #cbd5e1;
    border-radius:12px;
    outline:none;
    font-size:15px;
    transition:0.3s;
}

.input-box input:focus,
.input-box select:focus{
    border-color:#2563eb;
    box-shadow:0 0 0 4px rgba(37,99,235,0.15);
}

.row{
    display:flex;
    gap:15px;
}

.row .input-box{
    flex:1;
}

.radio-group{
    display:flex;
    gap:15px;
}

.radio-card{
    flex:1;
    padding:14px;
    border:2px solid #e2e8f0;
    border-radius:12px;
    cursor:pointer;
    transition:0.3s;
    font-weight:600;
}

.radio-card:hover{
    border-color:#2563eb;
    background:#eff6ff;
}

.card-preview{
    width:100%;
    height:210px;
    border-radius:20px;
    padding:25px;
    margin-bottom:25px;
    background:linear-gradient(135deg,#2563eb,#1d4ed8,#0f172a);
    color:white;
    position:relative;
    overflow:hidden;
}

.card-preview::before{
    content:'';
    position:absolute;
    width:250px;
    height:250px;
    background:rgba(255,255,255,0.1);
    border-radius:50%;
    top:-100px;
    right:-80px;
}

.bank{
    text-align:right;
    font-size:24px;
    font-weight:bold;
    letter-spacing:2px;
}

.card-number-preview{
    margin-top:45px;
    font-size:24px;
    letter-spacing:3px;
    font-weight:bold;
}

.card-bottom{
    display:flex;
    justify-content:space-between;
    margin-top:35px;
}

.card-bottom small{
    opacity:0.8;
}

.card-bottom p{
    margin-top:5px;
    font-weight:bold;
}

.pay-btn{
    background:linear-gradient(135deg,#2563eb,#1d4ed8);
    color:white;
    border:none;
    padding:16px;
    border-radius:14px;
    font-size:17px;
    font-weight:bold;
    cursor:pointer;
    transition:0.3s;
}

.pay-btn:hover{
    transform:translateY(-2px);
    opacity:0.95;
}

.message{
    padding:14px;
    border-radius:12px;
    margin-bottom:15px;
    text-align:center;
    font-weight:600;
}

.success{
    background:#dcfce7;
    color:#166534;
}

.error{
    background:#fee2e2;
    color:#991b1b;
}

@media(max-width:600px){

    .payment-container{
        padding:20px;
    }

    .row{
        flex-direction:column;
    }

    .card-number-preview{
        font-size:18px;
    }
}