/* Reset và Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* Header */
.header {
    background: white;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.header h1 {
    color: #667eea;
    font-size: 24px;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
}

.xu-badge {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: bold;
    font-size: 14px;
}

/* Auth Container */
.auth-container {
    background: white;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    max-width: 500px;
    margin: 50px auto;
}

.auth-tabs {
    display: flex;
    margin-bottom: 30px;
    border-bottom: 2px solid #eee;
}

.tab-btn {
    flex: 1;
    padding: 15px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    color: #999;
    transition: all 0.3s;
    position: relative;
}

.tab-btn.active {
    color: #667eea;
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: #667eea;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Forms */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #333;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #eee;
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    width: 100%;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-sm {
    padding: 8px 16px;
    font-size: 14px;
}

.btn-block {
    width: 100%;
}

/* Alerts */
.alert {
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
}

.alert-error {
    background: #fee;
    color: #c33;
    border: 1px solid #fcc;
}

.alert-success {
    background: #efe;
    color: #3c3;
    border: 1px solid #cfc;
}

.alert-success h3 {
    margin-bottom: 10px;
    color: #2a2;
}

.text-warning {
    color: #f59e0b;
    font-weight: 600;
}

.text-info {
    color: #3b82f6;
}

.text-center {
    text-align: center;
}

/* Cards */
.card {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.card h2 {
    color: #667eea;
    margin-bottom: 20px;
    font-size: 20px;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

/* Package Grid */
.package-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.package-item {
    display: block;
    cursor: pointer;
}

.package-item input[type="radio"] {
    display: none;
}

.package-content {
    padding: 20px;
    border: 2px solid #eee;
    border-radius: 8px;
    text-align: center;
    transition: all 0.3s;
}

.package-item input[type="radio"]:checked + .package-content {
    border-color: #667eea;
    background: #f0f4ff;
}

.package-amount {
    font-size: 18px;
    font-weight: bold;
    color: #667eea;
    margin-bottom: 10px;
}

.package-xu {
    font-size: 14px;
    color: #666;
}

.bonus {
    display: block;
    color: #10b981;
    font-weight: 600;
    margin-top: 5px;
}

/* Bank Info */
.bank-info {
    line-height: 1.8;
}

.bank-info p {
    margin-bottom: 10px;
}

.bank-info strong {
    color: #667eea;
}

/* Table */
.table-responsive {
    overflow-x: auto;
}

.table {
    width: 100%;
    border-collapse: collapse;
}

.table thead {
    background: #f8f9fa;
}

.table th,
.table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #eee;
}

.table th {
    font-weight: 600;
    color: #667eea;
}

/* Status Badge */
.status-badge {
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    display: inline-block;
}

.status-paid {
    background: #d1fae5;
    color: #065f46;
}

.status-unpaid {
    background: #fee2e2;
    color: #991b1b;
}

/* Responsive */
@media (max-width: 768px) {
    .auth-container {
        padding: 20px;
        margin: 20px auto;
    }

    .header {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
    }

    .dashboard-grid {
        grid-template-columns: 1fr;
    }

    .package-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .table {
        font-size: 14px;
    }
}