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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: #000;
    color: #fff;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Banner */
.banner {
    background-color: #dc2626;
    color: white;
    text-align: center;
    padding: 8px 16px;
}

.banner p {
    font-size: 14px;
    font-weight: 500;
}

/* Header */
header {
    background-color: #111;
    border-bottom: 1px solid #333;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s;
}

.logo:hover {
    color: #ccc;
}

nav {
    display: flex;
    gap: 32px;
}

.nav-btn {
    background: none;
    border: none;
    color: #999;
    padding: 8px 16px;
    cursor: pointer;
    transition: all 0.3s;
    border-bottom: 2px solid transparent;
}

.nav-btn:hover {
    color: #fff;
}

.nav-btn.active {
    color: #fff;
    border-bottom-color: #fff;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.balance {
    font-size: 14px;
    color: #999;
}

.cart-btn {
    background: none;
    border: 1px solid #333;
    color: #fff;
    padding: 8px 16px;
    cursor: pointer;
    transition: all 0.3s;
}

.cart-btn:hover {
    border-color: #fff;
}

/* Main Content */
main {
    padding: 32px 20px;
    min-height: calc(100vh - 200px);
}

.page {
    display: none;
}

.page.active {
    display: block;
}

.page-header {
    text-align: center;
    margin-bottom: 32px;
}

.page-header h2 {
    font-size: 32px;
    margin-bottom: 8px;
}

.page-header p {
    color: #999;
}

/* Category Filter */
.category-filter {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 32px;
    flex-wrap: wrap;
}

.filter-btn {
    background: #000;
    border: 1px solid #333;
    color: #fff;
    padding: 8px 16px;
    cursor: pointer;
    transition: all 0.3s;
}

.filter-btn:hover {
    border-color: #fff;
}

.filter-btn.active {
    background: #fff;
    color: #000;
    border-color: #fff;
}

/* Cards List */
.cards-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.card-item {
    background: #111;
    border: 1px solid #333;
    padding: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: border-color 0.3s;
}

.card-item:hover {
    border-color: #666;
}

.card-info {
    display: flex;
    align-items: center;
    gap: 16px;
}

.card-flag {
    font-size: 24px;
}

.card-details h3 {
    font-size: 16px;
    margin-bottom: 4px;
}

.card-details .country-bank {
    font-size: 14px;
    color: #999;
    margin-bottom: 4px;
}

.card-details .bin {
    font-size: 12px;
    color: #666;
    font-family: 'Courier New', monospace;
}

.card-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.card-price {
    font-size: 18px;
    font-weight: bold;
}

.buy-btn {
    background: #fff;
    color: #000;
    border: none;
    padding: 8px 16px;
    cursor: pointer;
    transition: all 0.3s;
}

.buy-btn:hover {
    background: #ccc;
}

/* Reviews */
.reviews-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.review-item {
    background: #111;
    border: 1px solid #333;
    padding: 24px;
    transition: border-color 0.3s;
}

.review-item:hover {
    border-color: #666;
}

.review-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.review-username {
    font-weight: 500;
}

.review-date {
    color: #999;
    font-size: 14px;
}

.review-comment {
    color: #ccc;
    line-height: 1.5;
}

/* Cart */
.empty-cart {
    text-align: center;
    padding: 48px;
    background: #111;
    border: 1px solid #333;
}

.empty-cart h3 {
    font-size: 24px;
    margin-bottom: 16px;
}

.empty-cart p {
    color: #999;
}

.cart-items {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 32px;
}

.cart-item {
    background: #111;
    border: 1px solid #333;
    padding: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.cart-item-info {
    display: flex;
    align-items: center;
    gap: 16px;
}

.cart-item-controls {
    display: flex;
    align-items: center;
    gap: 16px;
}

.quantity-controls {
    display: flex;
    align-items: center;
    gap: 8px;
}

.quantity-btn {
    background: none;
    border: 1px solid #333;
    color: #fff;
    width: 32px;
    height: 32px;
    cursor: pointer;
    transition: all 0.3s;
}

.quantity-btn:hover {
    border-color: #fff;
}

.quantity {
    width: 32px;
    text-align: center;
}

.remove-btn {
    background: none;
    border: 1px solid #333;
    color: #fff;
    padding: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.remove-btn:hover {
    border-color: #fff;
}

/* Payment Section */
.payment-section {
    background: #111;
    border: 1px solid #333;
    padding: 24px;
}

.payment-summary {
    margin-bottom: 24px;
}

.total {
    font-size: 18px;
    font-weight: bold;
    margin-bottom: 8px;
}

.balance-info {
    font-size: 14px;
    color: #999;
}

.payment-methods {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

.payment-btn {
    flex: 1;
    background: #000;
    border: 1px solid #333;
    color: #fff;
    padding: 12px;
    cursor: pointer;
    transition: all 0.3s;
}

.payment-btn:hover {
    border-color: #fff;
}

.payment-btn.active {
    background: #fff;
    color: #000;
    border-color: #fff;
}

.payment-option {
    margin-bottom: 24px;
}

.crypto-options {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

.crypto-btn {
    flex: 1;
    background: #000;
    border: 1px solid #333;
    color: #fff;
    padding: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.crypto-btn:hover {
    border-color: #fff;
}

.crypto-btn.active {
    background: #fff;
    color: #000;
    border-color: #fff;
}

.pay-btn {
    width: 100%;
    background: #fff;
    color: #000;
    border: none;
    padding: 12px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s;
}

.pay-btn:hover {
    background: #ccc;
}

.pay-btn:disabled {
    background: #333;
    color: #666;
    cursor: not-allowed;
}

.add-balance {
    border-top: 1px solid #333;
    padding-top: 24px;
}

.add-balance h3 {
    margin-bottom: 16px;
}

.balance-input {
    display: flex;
    gap: 8px;
}

.balance-input input {
    flex: 1;
    background: #000;
    border: 1px solid #333;
    color: #fff;
    padding: 8px 12px;
}

.balance-input input:focus {
    outline: none;
    border-color: #fff;
}

.balance-input button {
    background: #fff;
    color: #000;
    border: none;
    padding: 8px 16px;
    cursor: pointer;
    transition: all 0.3s;
}

.balance-input button:hover {
    background: #ccc;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 16px;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: #111;
    border: 1px solid #333;
    padding: 24px;
    max-width: 500px;
    width: 100%;
}

.modal-content h3 {
    font-size: 20px;
    margin-bottom: 16px;
}

.modal-content p {
    color: #ccc;
    margin-bottom: 16px;
}

.crypto-address {
    background: #000;
    border: 1px solid #333;
    padding: 16px;
    margin-bottom: 16px;
}

.crypto-address p {
    font-size: 14px;
    color: #999;
    margin-bottom: 8px;
}

.address-container {
    display: flex;
    align-items: center;
    gap: 8px;
}

.address-container code {
    flex: 1;
    font-size: 14px;
    word-break: break-all;
}

.address-container button {
    background: none;
    border: 1px solid #333;
    color: #fff;
    padding: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.address-container button:hover {
    border-color: #fff;
}

.payment-note {
    font-size: 14px;
    color: #999;
    margin-bottom: 24px;
}

.modal-buttons {
    display: flex;
    gap: 12px;
}

.modal-buttons button {
    flex: 1;
    padding: 12px;
    cursor: pointer;
    transition: all 0.3s;
}

.modal-buttons button:first-child {
    background: none;
    border: 1px solid #333;
    color: #fff;
}

.modal-buttons button:first-child:hover {
    border-color: #fff;
}

.modal-buttons button:last-child {
    background: #fff;
    color: #000;
    border: none;
}

.modal-buttons button:last-child:hover {
    background: #ccc;
}

/* Footer */
footer {
    background: #111;
    border-top: 1px solid #333;
    padding: 32px 0;
    text-align: center;
    color: #999;
}

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        height: auto;
        padding: 16px 0;
        gap: 16px;
    }

    nav {
        gap: 16px;
    }

    .category-filter {
        gap: 8px;
    }

    .filter-btn {
        padding: 6px 12px;
        font-size: 14px;
    }

    .card-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }

    .card-actions {
        width: 100%;
        justify-content: space-between;
    }

    .payment-methods {
        flex-direction: column;
    }

    .crypto-options {
        flex-direction: column;
    }

    .modal-buttons {
        flex-direction: column;
    }
}