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

body {
    font-family: Arial, sans-serif;
    background: url('Fileanh/hinhnen.png') no-repeat center center fixed;
    background-size: cover;
    margin: 0;
    padding: 0;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    max-width: 500px;
    background: #ffffff;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
    position: relative;
    overflow: hidden;
    margin: 20px;
    text-align: left;
}


h2 {
    text-align: center;
    margin-bottom: 20px;
    color: #333;
}

.alert-box {
    background: #fff3cd;
    border: 1px solid #ffeeba;
    color: #856404;
    padding: 10px 15px;
    margin-bottom: 15px;
    border-radius: 6px;
    font-size: 14px;
}

.form-group { margin-bottom: 15px; }
label { display: block; margin-bottom: 5px; font-weight: bold; }

select, input[type="text"] {
    width: 100%;
    padding: 10px;
    font-size: 14px;
    border: 1px solid #ccc;
    border-radius: 6px;
    box-sizing: border-box;
    height: 38px;
}

.captcha-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 10px 0;
}
.captcha-code {
    flex: 1;
    font-weight: bold;
    font-size: 18px;
    letter-spacing: 2px;
    background: #f1f1f1;
    padding: 6px 12px;
    border-radius: 4px;
    user-select: none;
    text-align: center;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.refresh-btn {
    padding: 0 12px;
    background: #007bff;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    height: 38px;
    flex-shrink: 0;
}
.refresh-btn:hover { background: #0056b3; }

.submit-btn {
    width: 100%;
    padding: 12px;
    background: #28a745;
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    cursor: pointer;
    margin-top: 10px;
}
.submit-btn:hover { background: #218838; }

.result-box {
    margin-top: 20px;
    padding: 15px;
    border-radius: 6px;
    display: none;
    background: #e9f7ef;
    border: 1px solid #d2dad4;
    color: #155724;
    font-size: 14px;
}
table.result-table { width: 100%; border-collapse: collapse; }
table.result-table td { padding: 8px; border-bottom: 1px solid #ddd; }
table.result-table td:first-child { font-weight: bold; width: 40%; }

.top-alert {
    width: 100%;
    background: #d9534f;
    color: #fff;
    text-align: center;
    padding: 8px 12px;
    font-size: 15px;
    font-weight: bold;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000;
}

body.with-top-alert .container {
    margin-top: 70px;
}