/* steel filter Styles - 2025年3月29日 */
:root {
    /* 主色调 */
    --primary-color: #ff6a00;
    --secondary-color: #2c3e50;
    --accent-color: #3498db;
    --text-color: #333;
    --light-gray: #f5f5f5;
    --border-color: #ddd;
    --dalon-primary: #455A64;     /* 深蓝灰色 - 代表钢制过滤器的金属质感和耐用性 */
    --dalon-secondary: #78909C;   /* 中蓝灰色 - 体现过滤器的工业特性和专业性 */
    --dalon-gray: #263238;        /* 深灰色 - 突出钢材的坚固性和高品质 */
/* 浅灰色 */
    
    /* 字体系统 */
    --font-primary: 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 0.875rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-xxl: 1.5rem;
    --line-height-base: 1.6;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-bold: 600;
    --letter-spacing-base: 0.5px;
}

/* 基础样式 */
body {
    font-family: var(--font-primary);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    color: var(--dalon-gray);
    background-color: var(--light-grey);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 标题样式 */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-primary);
    line-height: 1.3;
    margin-bottom: 1rem;
}

h1 { font-size: var(--font-size-xxl); font-weight: var(--font-weight-normal); }
h2 { font-size: var(--font-size-xl); font-weight: var(--font-weight-medium); }
h3 { font-size: var(--font-size-lg); font-weight: var(--font-weight-medium); }

/* Hero Banner */
.hero-banner {
    background: linear-gradient(135deg, var(--dalon-primary) 0%, #005694 100%);
    color: white;
    position: relative;
    overflow: hidden;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.hero-banner h1 {
    font-weight: 300;
    letter-spacing: var(--letter-spacing-base);
    margin-bottom: 0.75rem;
}

.hero-banner p {
    margin: 0 auto 0.75rem;
    opacity: 0.9;
}

/* 质量徽章 */
.quality-badge {
    display: inline-block;
    background-color: var(--dalon-secondary);
    color: var(--dalon-gray);
    padding: 0.25rem 1rem;
    border-radius: 30px;
    font-weight: var(--font-weight-medium);
    font-size: var(--font-size-sm);
    text-transform: uppercase;
    letter-spacing: var(--letter-spacing-base);
}

/* 产品卡片 */
.card {
    border: 1px solid rgba(0, 121, 107, 0.1);
    border-radius: 8px;
    transition: all 0.3s ease;
    margin-bottom: 30px;
    background-color: white;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 24px rgba(0, 121, 107, 0.15);
    border-color: var(--dalon-primary);
}

.card-img-top {
    object-fit: contain;
    height: auto;
    max-height: 220px;
    width: 100%;
    padding: 0.5em 0.5rem;
    transition: transform 0.3s ease;
    background-color: #fff;
}

.card:hover .card-img-top {
    transform: scale(1.05);
}

.card-body {
    padding: 1.25rem;
    padding-bottom: 1.5rem;
    border-top: 1px solid var(--dalon-primary);
    background: linear-gradient(to bottom, #ffffff 0%, #f8f9fa 100%);
    height: 100%;
    margin-bottom: 0;
}

.card-title {
    font-size: var(--font-size-lg);
    margin-bottom: 0.5rem;
    color: var(--dalon-primary);
    font-weight: var(--font-weight-medium);
    transition: color 0.3s ease;
}

.card:hover .card-title {
    color: var(--dalon-secondary);
}

.card-text {
    color: var(--dalon-gray);
    font-size: var(--font-size-sm);
    opacity: 0.8;
}

/* 产品卡片链接 */
.card a {
    text-decoration: none;
    color: inherit;
}

/* 产品卡片标记 */
.border-primary-top {
    position: relative;
    border-top: 2px solid var(--dalon-primary);
}

.border-primary-top::before {
    content: '';
    position: absolute;
    top: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(to right, var(--dalon-primary), var(--dalon-secondary));
    transition: all 0.3s ease;
    opacity: 1;
}

.border-primary-top:hover::before {
    opacity: 1;
    height: 3px;
    top: -3px;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .card {
        border-radius: 6px;
    }
    
    .card-img-top {
        padding: 0.5rem 0.25rem;
    }
    
    .card-body {
        padding: 1rem;
    }
}

/* 添加加载动画 */
@keyframes cardFadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card {
    animation: cardFadeIn 0.5s ease forwards;
}

/* 搜索和筛选区域 */
.form-control, .form-select {
    border-radius: 0;
    border: 1px solid var(--dalon-gray);
    padding: 0.5rem 1rem;
}

.form-control:focus, .form-select:focus {
    border-color: var(--dalon-primary);
    box-shadow: 0 0 0 0.2rem rgba(0, 64, 120, 0.25);
}

/* 分页导航 */
.pagination {
    margin-top: 2rem;
}

.page-link {
    color: var(--dalon-primary);
    border: none;
    padding: 0.5rem 1rem;
}

.page-item.active .page-link {
    background-color: var(--dalon-primary);
    border-color: var(--dalon-primary);
}

.page-link:hover {
    color: var(--dalon-secondary);
    background-color: var(--light-grey);
}

/* 响应式调整 */
@media (max-width: 768px) {
    :root {
        --font-size-base: 15px;
        --font-size-xxl: 1.35rem;
        --font-size-xl: 1.15rem;
        --font-size-lg: 1rem;
    }
    
    .quality-badge {
        font-size: 0.75rem;
    }
}

/* 卡片头部颜色 */
.filter-header {
    background-color: #004078;
}

.muffler-header {
    background-color: #004D40;
}

.bushing-header {
    background-color: #00695C;
}

.other-header {
    background-color: #546E7A;
}

/* Header Styles */
.top-header {
    background: var(--secondary-color);
    color: white;
    padding: 8px 0;
    font-size: 14px;
}

.top-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.contact-info {
    display: flex;
    gap: 20px;
}

.contact-info span {
    transition: color 0.3s;
    cursor: pointer;
}

.contact-info span:hover {
    color: var(--primary-color);
}

.language-selector {
    display: flex;
    align-items: center;
    gap: 8px;
}

.language-selector a {
    color: inherit;
    text-decoration: none;
    transition: color 0.3s;
}

.language-selector a:hover {
    color: var(--primary-color);
}

.main-header {
    padding: 20px 0;
    background: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    max-height: 60px;
}

.nav-menu {
    display: flex;
    gap: 30px;
}

.nav-menu a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-menu a:hover {
    color: var(--primary-color);
}

.products-area {
    background-color: var(--light-grey);
}

.advantages-area {
    background-color: white;
}

.cta-area {
    background-color: var(--dalon-primary);
}

/* 间距调整 */
.py-4 {
    padding-top: 1.5rem !important;
    padding-bottom: 1.5rem !important;
}

.mb-4 {
    margin-bottom: 1.5rem !important;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    cursor: pointer;
}

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

.btn-primary:hover {
    background: #ff8533;
    transform: translateY(-2px);
}

.btn-secondary {
    background: white;
    color: var(--primary-color);
}

.btn-secondary:hover {
    background: #f5f5f5;
    transform: translateY(-2px);
}

/* Footer Styles */
footer {
    background: var(--secondary-color);
    color: white;
    padding: 8px 0;
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 14px;
}

.footer-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-right a {
    color: inherit;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-right a:hover {
    color: var(--primary-color);
}

.footer-divider {
    margin: 0 8px;
    color: rgba(255,255,255,0.5);
}

/* Error Message Styles */
.error-message {
    background: #fff3f3;
    color: #dc3545;
    padding: 15px;
    border-radius: 5px;
    margin: 20px 0;
    text-align: center;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .hero h1 {
        font-size: 36px;
    }

    .hero p {
        font-size: 18px;
    }

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

    .feature-card,
    .product-card {
        margin-bottom: 20px;
    }

    .footer-container {
        flex-direction: column;
        gap: 15px;
        padding: 15px 0;
    }

    .footer-right {
        flex-wrap: wrap;
        justify-content: center;
    }

    .contact-info {
        flex-direction: column;
        gap: 5px;
    }

    .language-selector {
        display: none;
    }

    .product-actions {
        flex-direction: column;
        gap: 10px;
        align-items: stretch;
    }
    
    .category-tag {
        text-align: center;
    }
    
    .product-actions .btn {
        margin-left: 0;
        text-align: center;
    }
}

/* Header 样式更新 */
.header-left {
    display: flex;
    align-items: center;
    gap: 20px;
}

.menu-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    color: var(--secondary-color);
    font-size: 16px;
    transition: color 0.3s;
    -webkit-tap-highlight-color: transparent;
    user-select: none;
    -webkit-user-select: none;
}

.menu-btn:hover {
    color: var(--primary-color);
}

.menu-icon {
    font-size: 20px;
}

.menu-text {
    font-weight: 500;
    letter-spacing: 1px;
}

/* 侧边菜单样式 */
.side-menu-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 9999;
    visibility: hidden;
    -webkit-transform: translateZ(0);
    transform: translateZ(0);
    will-change: visibility;
}

.side-menu-wrapper.active {
    visibility: visible;
}

.side-menu {
    position: fixed;
    top: 0;
    left: -320px;
    width: 320px;
    height: 100%;
    background: rgba(44, 62, 80, 0.95);
    box-shadow: 2px 0 10px rgba(0,0,0,0.1);
    transition: transform 0.3s ease-out;
    -webkit-transition: -webkit-transform 0.3s ease-out;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    z-index: 2;
    will-change: transform;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

.side-menu-wrapper.active .side-menu {
    transform: translateX(320px);
    -webkit-transform: translateX(320px);
}

.side-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    opacity: 0;
    transition: opacity 0.3s ease-out;
    -webkit-transition: opacity 0.3s ease-out;
    z-index: 1;
    will-change: opacity;
    pointer-events: none;
}

.side-menu-wrapper.active .side-menu-overlay {
    opacity: 1;
    pointer-events: auto;
}

.side-menu-header {
    padding: 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: flex-end;
}

.close-menu {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #fff;
    padding: 5px;
    transition: color 0.3s;
}

.close-menu:hover {
    color: var(--primary-color);
}

.side-menu-content {
    padding: 20px;
}

.menu-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.menu-item {
    margin-bottom: 0 !important;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05) !important;
}

.menu-item:last-child {
    border-bottom: none !important;
}

.menu-link {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: #fff;
    text-decoration: none;
    font-size: 16px;
    padding: 15px 10px !important;
    transition: all 0.3s ease;
}

.menu-link:hover {
    color: var(--primary-color);
    background-color: rgba(255, 255, 255, 0.05);
}

.submenu {
    list-style: none;
    padding: 0;
    margin: 0;
    background: transparent;
    border-radius: 0;
    border-left: none;
    display: block !important;
    padding-left: 15px;
}

.submenu li {
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin: 0;
}

.submenu li:last-child {
    border-bottom: none;
}

.submenu a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    padding: 12px 15px 12px 15px;
    display: block;
    font-size: 14px;
    transition: all 0.3s;
    position: relative;
}

.submenu a:before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.3);
    transition: background-color 0.3s, transform 0.2s;
}

.submenu a:hover {
    color: var(--primary-color);
    background: rgba(255, 255, 255, 0.05);
    padding-left: 20px;
}

.submenu a:hover:before {
    background-color: var(--primary-color);
    transform: translateY(-50%) scale(1.2);
}

.has-submenu > .menu-link {
    color: #fff;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 14px;
    padding: 15px 0 15px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.15) !important;
    background-color: transparent;
    display: block;
    padding-left: 10px;
    position: relative;
}

.has-submenu > .menu-link:after {
    content: none;
}

/* 禁止滚动类 */
.no-scroll {
    overflow: hidden !important;
    width: 100%;
    position: fixed;
    overscroll-behavior: none;
    -ms-scroll-chaining: none;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .menu-btn {
        padding: 5px;
    }
    
    .menu-text {
        display: none;
    }
    
    .side-menu {
        width: 280px;
        left: -280px;
    }
    
    .side-menu-wrapper.active .side-menu {
        transform: translateX(280px);
    }
}

/* 优化滚动条样式 */
.side-menu::-webkit-scrollbar {
    width: 6px;
}

.side-menu::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.1);
}

.side-menu::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
}

.side-menu::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* 返回顶部按钮样式 */
#topBtn {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--secondary-color);
    border: none;
    opacity: 0.8;
    transition: all 0.3s;
    border-radius: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 1000;
    color: white;
}

#topBtn:hover {
    opacity: 1;
}

#topBtn svg {
    transition: transform 0.3s;
}

#topBtn:hover svg {
    transform: translateY(-2px);
}

/* 响应式字体调整 */
@media (max-width: 768px) {
    :root {
        --font-size-base: 15px;
        --font-size-xxl: 1.35rem;
        --font-size-xl: 1.15rem;
        --font-size-lg: 1rem;
    }
    
    .product-category-title {
        font-size: 0.8rem;
    }
    
    .quality-badge {
        font-size: 0.75rem;
    }
}