:root {
    --bg: #F5F0E1;
    --card: #FFFFFF;
    --border: #1A1A1A;
    --text: #1A1A1A;
    --text-sec: #888888;
    --btn-bg: #1A1A1A;
    --btn-text: #FFFFFF;
    --disabled: #E0E0E0;
    --line-price: #999999;
    --success: #34D399;
    --error: #F87171;
    --accent: #FF7EB9;
    --accent2: #7ED6FF;
    --shadow-offset: 4px;
    --border-width: 3px;
    --radius: 12px;
    --radius-sm: 8px;
}

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

body {
    font-family: 'Comic Sans MS', 'Marker Felt', 'Noto Sans SC', system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }
img { display: block; max-width: 100%; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input, textarea, select { font-family: inherit; font-size: inherit; }

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

/* === Header === */
.header {
    border-bottom: var(--border-width) solid var(--border);
    background: var(--card);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 14px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 22px;
    font-weight: 800;
    white-space: nowrap;
}

.logo-icon {
    width: 36px;
    height: 36px;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    background: var(--accent);
}

.search-bar {
    flex: 1;
    max-width: 400px;
    position: relative;
}

.search-bar input {
    width: 100%;
    padding: 10px 14px 10px 40px;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--card);
    font-size: 14px;
    outline: none;
}

.search-bar input:focus {
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--border);
    transform: translate(-2px, -2px);
    transition: all 0.15s;
}

.search-bar .search-icon {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 18px;
    color: var(--text-sec);
}

.header-actions {
    display: flex;
    gap: 10px;
    align-items: center;
    margin-left: auto;
}

/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 20px;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 700;
    transition: transform 0.12s, box-shadow 0.12s;
    white-space: nowrap;
}

.btn-primary {
    background: var(--btn-bg);
    color: var(--btn-text);
}

.btn-primary:hover {
    transform: translate(-2px, -2px);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--border);
}

.btn-primary:active {
    transform: translate(0, 0);
    box-shadow: none;
}

.btn-outline {
    background: var(--card);
    color: var(--text);
}

.btn-outline:hover {
    background: var(--bg);
    transform: translate(-2px, -2px);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--border);
}

.btn-disabled {
    background: var(--disabled);
    color: var(--text-sec);
    border-color: var(--text-sec);
    cursor: not-allowed;
}

.btn-sm {
    padding: 6px 14px;
    font-size: 13px;
}

.btn-lg {
    padding: 14px 28px;
    font-size: 16px;
}

.btn-block {
    display: flex;
    width: 100%;
}

/* === Category Tabs === */
.categories {
    display: flex;
    gap: 8px;
    padding: 16px 20px;
    max-width: 1200px;
    margin: 0 auto;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.cat-tab {
    padding: 6px 18px;
    border: 2px solid var(--border);
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    background: var(--card);
    white-space: nowrap;
    cursor: pointer;
    transition: all 0.12s;
}

.cat-tab:hover {
    transform: translateY(-2px);
}

.cat-tab.active {
    background: var(--btn-bg);
    color: var(--btn-text);
}

/* === Sort Bar === */
.sort-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.sort-bar label {
    font-size: 13px;
    color: var(--text-sec);
}

.sort-bar select {
    padding: 6px 12px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--card);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    outline: none;
}

/* === Product Grid === */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 20px;
    padding: 16px 20px 60px;
    max-width: 1200px;
    margin: 0 auto;
}

.product-card {
    background: var(--card);
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: transform 0.15s, box-shadow 0.15s;
    cursor: pointer;
}

.product-card:hover {
    transform: translate(-3px, -3px);
    box-shadow: 6px 6px 0 var(--border);
}

.product-card.no-image .card-body {
    border-top-left-radius: var(--radius);
    border-top-right-radius: var(--radius);
}

.product-card .card-image {
    width: 100%;
    aspect-ratio: 16/10;
    object-fit: cover;
    border-bottom: var(--border-width) solid var(--border);
    background: var(--bg);
}

.product-card .card-body {
    padding: 14px;
}

.product-card .card-cat-tag {
    display: inline-block;
    padding: 2px 8px;
    border: 2px solid var(--border);
    border-radius: 4px;
    font-size: 11px;
    font-weight: 700;
    margin-bottom: 8px;
    background: var(--accent2);
}

.product-card .card-title {
    font-size: 16px;
    font-weight: 800;
    margin-bottom: 4px;
    line-height: 1.3;
}

.product-card .card-desc {
    font-size: 13px;
    color: var(--text-sec);
    margin-bottom: 10px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.product-card .card-price {
    display: flex;
    align-items: baseline;
    gap: 8px;
    margin-bottom: 10px;
}

.product-card .price-now {
    font-size: 22px;
    font-weight: 800;
}

.product-card .price-old {
    font-size: 14px;
    color: var(--line-price);
    text-decoration: line-through;
}

.product-card .card-divider {
    border-top: 2px dashed var(--border);
    margin: 8px 0;
}

.product-card .card-meta {
    display: flex;
    justify-content: space-between;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 10px;
}

.product-card .card-meta span {
    display: flex;
    align-items: center;
    gap: 4px;
}

.product-card .card-btn {
    display: block;
    width: 100%;
    padding: 10px;
    text-align: center;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 800;
    letter-spacing: 1px;
}

.card-btn.buy {
    background: var(--btn-bg);
    color: var(--btn-text);
}

.card-btn.sold {
    background: var(--disabled);
    color: var(--text-sec);
    border-color: var(--text-sec);
    cursor: not-allowed;
}

/* === Modal === */
.modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal-overlay.show {
    display: flex;
    animation: fadeIn 0.2s ease;
}

.modal {
    background: var(--card);
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius);
    box-shadow: 6px 6px 0 var(--border);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    animation: popIn 0.25s ease;
}

.modal-lg {
    max-width: 800px;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 2px dashed var(--border);
}

.modal-header h3 {
    font-size: 18px;
    font-weight: 800;
}

.modal-close {
    width: 32px;
    height: 32px;
    border: 2px solid var(--border);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 700;
    background: var(--card);
    transition: all 0.12s;
}

.modal-close:hover {
    background: var(--error);
    color: #fff;
    transform: rotate(90deg);
}

.modal-body {
    padding: 20px;
}

.modal-footer {
    padding: 16px 20px;
    border-top: 2px dashed var(--border);
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

/* === Form === */
.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 6px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px 14px;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--card);
    font-size: 14px;
    outline: none;
    transition: all 0.12s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    transform: translate(-1px, -1px);
    box-shadow: 3px 3px 0 var(--border);
}

.form-group .error-msg {
    color: var(--error);
    font-size: 13px;
    margin-top: 4px;
    min-height: 18px;
}

.form-row {
    display: flex;
    gap: 12px;
}

.form-row .form-group {
    flex: 1;
}

.form-check {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
}

.form-check input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--border);
}

.form-link {
    color: var(--text);
    font-weight: 700;
    text-decoration: underline;
    cursor: pointer;
}

.form-footer-text {
    text-align: center;
    font-size: 14px;
    margin-top: 12px;
}

/* === Toast === */
.toast-container {
    position: fixed;
    top: 80px;
    right: 20px;
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.toast {
    padding: 12px 20px;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--card);
    font-size: 14px;
    font-weight: 600;
    box-shadow: 4px 4px 0 var(--border);
    animation: slideIn 0.25s ease;
    max-width: 320px;
}

.toast.success { border-color: var(--success); }
.toast.error { border-color: var(--error); }
.toast.info { border-color: var(--accent2); }

/* === Product Detail Modal === */
.detail-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.detail-left .detail-image {
    width: 100%;
    aspect-ratio: 16/10;
    object-fit: cover;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    margin-bottom: 14px;
}

.detail-left h2 {
    font-size: 22px;
    font-weight: 800;
    margin-bottom: 8px;
}

.detail-left .detail-cat-tag {
    display: inline-block;
    padding: 2px 10px;
    border: 2px solid var(--border);
    border-radius: 4px;
    font-size: 12px;
    font-weight: 700;
    margin-bottom: 10px;
    background: var(--accent2);
}

.detail-left .detail-price {
    display: flex;
    align-items: baseline;
    gap: 10px;
    margin-bottom: 12px;
}

.detail-left .detail-price .now {
    font-size: 28px;
    font-weight: 800;
}

.detail-left .detail-price .old {
    font-size: 16px;
    color: var(--line-price);
    text-decoration: line-through;
}

.detail-meta {
    display: flex;
    gap: 20px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 12px;
}

.detail-desc {
    border-top: 2px dashed var(--border);
    padding-top: 12px;
    font-size: 14px;
    line-height: 1.7;
    color: var(--text);
}

.detail-right .qty-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.qty-btn {
    width: 36px;
    height: 36px;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 18px;
    font-weight: 800;
    background: var(--card);
    display: flex;
    align-items: center;
    justify-content: center;
}

.qty-btn:hover { background: var(--bg); }

.qty-input {
    width: 60px;
    text-align: center;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    padding: 8px;
    font-size: 16px;
    font-weight: 700;
    outline: none;
}

.pay-methods {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-bottom: 12px;
}

.pay-option {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 10px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.12s;
    font-size: 13px;
}

.pay-option:hover { background: var(--bg); }
.pay-option.selected { background: var(--accent2); font-weight: 700; }
.pay-option input { accent-color: var(--border); width:14px;height:14px; }

.order-summary {
    border: 2px dashed var(--border);
    border-radius: var(--radius-sm);
    padding: 12px;
    margin-bottom: 16px;
    font-size: 14px;
}

.order-summary .summary-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 4px;
}

.order-summary .summary-total {
    border-top: 2px dashed var(--border);
    padding-top: 8px;
    margin-top: 8px;
    font-size: 18px;
    font-weight: 800;
}

/* === Pay Modal === */
.pay-qr-area {
    text-align: center;
    padding: 20px;
}

.pay-qr-area img {
    margin: 0 auto 16px;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
}

.pay-countdown {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 16px;
}

.pay-amount {
    font-size: 24px;
    font-weight: 800;
    margin-bottom: 8px;
}

/* === Success Modal === */
.success-icon {
    text-align: center;
    font-size: 48px;
    margin-bottom: 12px;
}

.success-title {
    text-align: center;
    font-size: 20px;
    font-weight: 800;
    margin-bottom: 16px;
    color: var(--success);
}

.card-keys {
    border: 2px dashed var(--border);
    border-radius: var(--radius-sm);
    padding: 14px;
    margin-bottom: 16px;
}

.card-key-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 0;
    border-bottom: 1px dashed var(--border);
    font-size: 14px;
    word-break: break-all;
}

.card-key-item:last-child { border-bottom: none; }

.card-key-item .key-text {
    flex: 1;
    font-family: monospace;
    font-weight: 600;
}

.copy-btn {
    padding: 4px 12px;
    border: 2px solid var(--border);
    border-radius: 4px;
    font-size: 12px;
    font-weight: 700;
    background: var(--card);
    white-space: nowrap;
}

.copy-btn:hover { background: var(--btn-bg); color: var(--btn-text); }

/* === User Center === */
.user-center {
    display: none;
    padding: 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.user-center.show { display: block; }

.uc-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 20px;
}

.uc-tab {
    padding: 8px 20px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 700;
    background: var(--card);
    cursor: pointer;
}

.uc-tab.active {
    background: var(--btn-bg);
    color: var(--btn-text);
}

.uc-content { display: none; }
.uc-content.active { display: block; }

.uc-balance-card {
    background: var(--card);
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 20px;
    text-align: center;
}

.uc-balance-card .balance-label {
    font-size: 14px;
    color: var(--text-sec);
    margin-bottom: 8px;
}

.uc-balance-card .balance-amount {
    font-size: 36px;
    font-weight: 800;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--card);
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}

.data-table th,
.data-table td {
    padding: 12px 14px;
    text-align: left;
    font-size: 14px;
    border-bottom: 2px dashed var(--border);
}

.data-table th {
    background: var(--bg);
    font-weight: 800;
    font-size: 13px;
}

.data-table tr:last-child td { border-bottom: none; }

.status-badge {
    display: inline-block;
    padding: 2px 10px;
    border: 2px solid var(--border);
    border-radius: 4px;
    font-size: 12px;
    font-weight: 700;
}

.status-pending { background: #FFF3CD; }
.status-paid { background: var(--success); color: #fff; border-color: var(--success); }
.status-cancelled { background: var(--disabled); }
.status-refunded { background: var(--error); color: #fff; border-color: var(--error); }

/* === Empty State === */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-sec);
}

.empty-state .empty-icon {
    font-size: 48px;
    margin-bottom: 12px;
}

/* === Pagination === */
.pagination {
    display: flex;
    gap: 6px;
    justify-content: center;
    padding: 20px;
}

.page-btn {
    padding: 6px 14px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 700;
    background: var(--card);
    cursor: pointer;
}

.page-btn:hover { background: var(--bg); }
.page-btn.active { background: var(--btn-bg); color: var(--btn-text); }
.page-btn:disabled { opacity: 0.4; cursor: not-allowed; }

/* === Customer Service Float === */
.cs-float {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 900;
}

.cs-float-btn {
    width: 52px;
    height: 52px;
    border: var(--border-width) solid var(--border);
    border-radius: 50%;
    background: var(--btn-bg);
    color: var(--btn-text);
    font-size: 14px;
    font-weight: 800;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 4px 4px 0 var(--border);
    transition: transform 0.15s;
}

.cs-float-btn:hover {
    transform: translate(-2px, -2px);
    box-shadow: 6px 6px 0 var(--border);
}

.cs-panel {
    display: none;
    position: absolute;
    bottom: 62px;
    right: 0;
    width: 240px;
    background: var(--card);
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius);
    box-shadow: 6px 6px 0 var(--border);
    padding: 14px;
}

.cs-panel.show { display: block; animation: popIn 0.2s ease; }

.cs-panel h4 {
    font-size: 14px;
    font-weight: 800;
    margin-bottom: 10px;
    padding-bottom: 8px;
    border-bottom: 2px dashed var(--border);
}

.cs-item {
    display: block;
    padding: 8px 10px;
    margin-bottom: 6px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-weight: 600;
    transition: all 0.12s;
}

.cs-item:hover {
    background: var(--bg);
    transform: translate(-1px, -1px);
    box-shadow: 2px 2px 0 var(--border);
}

.cs-item .cs-item-title {
    font-weight: 800;
    margin-bottom: 2px;
}

.cs-item .cs-item-content {
    font-size: 12px;
    color: var(--text-sec);
}

/* === Recharge === */
.recharge-amounts {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
    margin-bottom: 16px;
}

.recharge-amount {
    padding: 10px 6px;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
    text-align: center;
    font-size: 16px;
    font-weight: 800;
    cursor: pointer;
    transition: all 0.12s;
    background: var(--card);
}

.recharge-amount:hover {
    transform: translate(-1px, -1px);
    box-shadow: 2px 2px 0 var(--border);
}

.recharge-amount.active {
    background: var(--btn-bg);
    color: var(--btn-text);
}

/* === Lottery === */
.lottery-card {
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    margin-bottom: 16px;
}

.lottery-card .lottery-header {
    background: var(--btn-bg);
    color: var(--btn-text);
    padding: 14px 20px;
    font-size: 18px;
    font-weight: 800;
}

.lottery-card .lottery-body {
    padding: 20px;
}

.lottery-info-row {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 2px dashed var(--border);
    font-size: 14px;
}

.lottery-info-row:last-child { border-bottom: none; }

.lottery-info-row .label { color: var(--text-sec); }
.lottery-info-row .value { font-weight: 700; }

.lottery-progress {
    height: 24px;
    border: 2px solid var(--border);
    border-radius: 12px;
    background: var(--bg);
    overflow: hidden;
    margin: 12px 0;
    position: relative;
}

.lottery-progress-bar {
    height: 100%;
    background: var(--accent);
    transition: width 0.3s;
}

.lottery-progress-text {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    text-align: center;
    line-height: 20px;
    font-size: 12px;
    font-weight: 700;
}

/* === Image Upload === */
.img-upload-area {
    border: var(--border-width) dashed var(--border);
    border-radius: var(--radius-sm);
    padding: 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.15s;
    background: var(--bg);
}

.img-upload-area:hover {
    background: var(--card);
    transform: translate(-1px, -1px);
    box-shadow: 2px 2px 0 var(--border);
}

.img-upload-area .upload-placeholder {
    color: var(--text-sec);
    font-size: 14px;
    font-weight: 600;
}

.img-preview {
    position: relative;
    display: inline-block;
}

.img-preview img {
    max-width: 200px;
    max-height: 140px;
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-sm);
}

.img-preview .img-remove {
    position: absolute;
    top: -8px;
    right: -8px;
    width: 24px;
    height: 24px;
    border: 2px solid var(--border);
    border-radius: 50%;
    background: var(--error);
    color: #fff;
    font-size: 14px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

/* === Deerflow Signature === */
.deerflow-sig {
    text-align: center;
    padding: 20px;
    font-size: 13px;
    color: var(--text-sec);
}

.deerflow-sig a {
    color: var(--text-sec);
    font-weight: 600;
    border-bottom: 1px dashed var(--text-sec);
}

.deerflow-sig a:hover {
    color: var(--text);
    border-color: var(--text);
}

/* === Animations === */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes popIn {
    from { opacity: 0; transform: scale(0.9) translateY(20px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(100%); }
    to { opacity: 1; transform: translateX(0); }
}

/* === Responsive === */
@media (max-width: 768px) {
    .header-inner { flex-wrap: wrap; gap: 8px; }
    .search-bar { order: 3; flex: 1 1 100%; max-width: 100%; }
    .detail-layout { grid-template-columns: 1fr; }
    .product-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
    .modal { max-width: 100%; }
    .data-table { font-size: 12px; }
    .data-table th, .data-table td { padding: 8px; }
}

@media (max-width: 480px) {
    .product-grid { grid-template-columns: 1fr; }
    .header-actions .btn { padding: 8px 12px; font-size: 13px; }
}