:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #eff6ff;
    --border: #e2e8f0;
    --text: #0f172a;
    --text-muted: #64748b;
    --text-light: #94a3b8;
    --error: #ef4444;
    --success: #10b981;
    --warning: #fbbf24;
    --white: #ffffff;
    --radius: 14px;
    --shadow: 0 4px 24px -6px rgba(15, 23, 42, 0.06);
    --transition: all 0.2s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    -webkit-tap-highlight-color: transparent;
}

body {
    background: #f5f7fa;
    min-height: 100vh;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

.header {
    background: var(--white);
    padding: 16px 20px;
    box-shadow: 0 1px 3px rgba(15, 23, 42, 0.08);
    position: relative;
    z-index: 2;
}

.logo-area img {
    height: 34px;
    width: auto;
}

.main-container {
    max-width: 480px;
    margin: 24px auto;
    padding: 0 16px;
}

/* Product Container Styles */
.product-container {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 24px;
    margin-bottom: 32px;
}

.product-gallery {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 12px;
    margin-bottom: 24px;
}

.main-image {
    height: 380px;
    border-radius: var(--radius);
    overflow: hidden;
    background: #f8fafc;
}

.main-image img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    padding: 20px;
    transition: transform 0.3s ease;
}

.side-images {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.side-image {
    height: 184px;
    border-radius: var(--radius);
    overflow: hidden;
    background: #f8fafc;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid var(--border);
}

.side-image.active {
    border-color: var(--primary);
}

.side-image img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    padding: 12px;
    transition: transform 0.3s ease;
}

.side-image:hover img {
    transform: scale(1.05);
}

/* Product Info Styles */
.product-title {
    font-size: 24px;
    color: var(--text);
    margin-bottom: 12px;
    font-weight: 600;
    line-height: 1.3;
}

.stock-info {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--success);
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 16px;
}

.product-price-container {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.product-price {
    font-size: 32px;
    color: var(--primary);
    font-weight: 600;
}

.original-price {
    font-size: 20px;
    color: var(--text-light);
    text-decoration: line-through;
}

.discount-badge {
    background: #fef2f2;
    color: var(--error);
    padding: 4px 12px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
}

/* Product Tabs */
.product-tabs {
    margin: 30px 0;
}

.tab-buttons {
    display: flex;
    gap: 24px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 20px;
}

.tab-button {
    padding: 12px 4px;
    font-weight: 500;
    color: var(--text-muted);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: var(--transition);
    margin-bottom: -1px;
}

.tab-button.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

.tab-content {
    display: none;
    padding: 4px;
}

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

.product-description {
    color: var(--text-muted);
    line-height: 1.7;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin: 24px 0;
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 16px;
    background: #f8fafc;
    border-radius: 12px;
    transition: var(--transition);
}

.feature-item:hover {
    background: var(--primary-light);
}

.feature-item i {
    color: var(--primary);
    font-size: 18px;
    margin-top: 2px;
}

.feature-info h4 {
    font-size: 14px;
    color: var(--text);
    margin-bottom: 4px;
    font-weight: 600;
}

.feature-info p {
    font-size: 13px;
    color: var(--text-muted);
    line-height: 1.5;
}

/* Reviews Section */
.reviews-section {
    margin-top: 20px;
}

.review-summary {
    display: flex;
    align-items: center;
    gap: 30px;
    padding: 24px;
    background: #f8fafc;
    border-radius: var(--radius);
    margin-bottom: 24px;
}

.rating-big {
    text-align: center;
    min-width: 140px;
}

.rating-big .number {
    font-size: 48px;
    font-weight: 600;
    color: var(--text);
    line-height: 1;
}

.rating-big .stars {
    color: var(--warning);
    font-size: 20px;
    margin: 8px 0;
}

.rating-big .total {
    font-size: 13px;
    color: var(--text-muted);
}

.rating-bars {
    flex: 1;
}

.rating-bar {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.rating-bar:last-child {
    margin-bottom: 0;
}

.rating-bar .stars {
    width: 80px;
    font-size: 13px;
    color: var(--text-muted);
}

.rating-bar .bar {
    flex: 1;
    height: 6px;
    background: #e2e8f0;
    border-radius: 3px;
    overflow: hidden;
}

.rating-bar .bar-fill {
    height: 100%;
    background: var(--warning);
    border-radius: 3px;
    transition: width 0.5s ease;
}

.rating-bar .count {
    width: 45px;
    font-size: 13px;
    color: var(--text-muted);
    text-align: right;
}
/* Review Cards */
.review-card {
    padding: 20px;
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 16px;
    transition: var(--transition);
}

.review-card:hover {
    border-color: var(--primary);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.08);
}

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

.reviewer-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.reviewer-avatar {
    width: 44px;
    height: 44px;
    border-radius: 22px;
    background: #f8fafc;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 18px;
}

.reviewer-name {
    font-weight: 500;
    color: var(--text);
    margin-bottom: 2px;
}

.review-date {
    font-size: 13px;
    color: var(--text-muted);
}

.review-rating {
    color: var(--warning);
    font-size: 14px;
    letter-spacing: 1px;
}

.review-text {
    color: var(--text-muted);
    font-size: 14px;
    line-height: 1.6;
}

/* Form Styles */
.form-container {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 32px 28px;
}

.form-header {
    text-align: center;
    margin-bottom: 28px;
}

.form-header h2 {
    font-size: 22px;
    color: var(--text);
    margin-bottom: 8px;
    font-weight: 600;
}

.form-header p {
    color: var(--text-muted);
    font-size: 14px;
}

.form-group {
    margin-bottom: 22px;
    position: relative;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text);
    font-weight: 500;
    font-size: 14px;
}

.form-group i {
    position: absolute;
    left: 16px;
    top: 43px;
    color: var(--text-light);
    font-size: 16px;
    transition: var(--transition);
    pointer-events: none;
}

.input-info {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 6px;
}

input[type="text"],
input[type="email"],
input[type="tel"],
textarea {
    width: 100%;
    padding: 16px 18px 16px 48px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    font-size: 15px;
    transition: var(--transition);
    background: var(--white);
    color: var(--text);
    -webkit-appearance: none;
    appearance: none;
}

textarea {
    min-height: 100px;
    resize: vertical;
}

input:focus,
textarea:focus {
    border-color: var(--primary);
    outline: none;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

input:focus + i,
textarea:focus + i {
    color: var(--primary);
}

/* Order Summary */
.order-summary {
    background: #f8fafc;
    border-radius: var(--radius);
    padding: 20px;
    margin: 24px 0;
}

.summary-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    color: var(--text-muted);
    font-size: 14px;
}

.summary-item.discount {
    color: var(--error);
}

.summary-item.shipping {
    color: var(--success);
}

.summary-total {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 12px;
    margin-top: 12px;
    border-top: 1px solid var(--border);
    font-weight: 600;
    color: var(--text);
    font-size: 16px;
}

/* Payment Methods */
.payment-methods {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin: 24px 0;
    padding: 16px;
    border-radius: var(--radius);
    background: #f8fafc;
}

.payment-methods img {
    height: 24px;
    width: auto;
}

/* Submit Button */
.submit-btn {
    background: var(--primary);
    color: var(--white);
    width: 100%;
    padding: 16px;
    border: none;
    border-radius: var(--radius);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.submit-btn:hover:not(:disabled) {
    background: var(--primary-dark);
}

.submit-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Additional Info */
.additional-info {
    margin-top: 24px;
    padding: 20px;
    background: var(--primary-light);
    border-radius: var(--radius);
}

.additional-info p {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 10px;
    color: var(--primary-dark);
    font-size: 13px;
}

.additional-info p:last-child {
    margin-bottom: 0;
}

.additional-info i {
    font-size: 14px;
}

.payment-info {
    text-align: center;
    margin-top: 20px;
    color: var(--text-muted);
    font-size: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

/* Responsive Design */
@media (max-width: 480px) {
    .main-container {
        padding: 0 12px;
        margin: 16px auto;
    }

    .product-gallery {
        display: flex;
        flex-direction: column;
    }

    .main-image {
        height: 300px;
    }

    .side-images {
        flex-direction: row;
    }

    .side-image {
        height: 140px;
        flex: 1;
    }

    .product-title {
        font-size: 20px;
    }

    .product-price {
        font-size: 28px;
    }

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

    .review-summary {
        flex-direction: column;
        gap: 20px;
        padding: 20px;
    }

    .rating-big .number {
        font-size: 36px;
    }

    .form-container {
        padding: 24px 20px;
    }

    .form-header h2 {
        font-size: 20px;
    }

    .additional-info {
        padding: 16px;
    }

    .order-summary {
        padding: 16px;
    }

    .payment-methods {
        flex-wrap: wrap;
        padding: 12px;
    }

    .payment-methods img {
        height: 20px;
    }
}