:root {
    --primary-color: #1a365d;
    --primary-light: #2d4a7c;
    --primary-dark: #0f2544;
    --secondary-color: #dc2626;
    --accent-color: #f59e0b;
    --accent-light: #fbbf24;
    --accent-dark: #d97706;
    --success-color: #10b981;
    --info-color: #3b82f6;
    --light-color: #f8fafc;
    --dark-color: #1e293b;
    --text-color: #334155;
    --text-light: #64748b;
    --border-color: #e2e8f0;
    --gray-color: #f1f5f9;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --box-shadow-hover: 0 10px 40px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* 标准品牌色 */
    --asme-color: #dc2626;
    --astm-color: #1a365d;
    --gb-color: #10b981;
    --en-color: #3b82f6;
    --as-color: #f97316;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', 'Noto Sans SC', sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background-color: #ffffff;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    color: var(--dark-color);
    line-height: 1.3;
}

h1 {
    font-size: 3.2rem;
    margin-bottom: 1.5rem;
    letter-spacing: -0.5px;
}

h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    position: relative;
    padding-bottom: 0.8rem;
}

h2:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-color), var(--secondary-color));
    border-radius: 2px;
}

.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 5rem 0;
}

.section-gray {
    background-color: var(--gray-color);
    position: relative;
}

/* Header */
header {
    background-color: rgba(255, 255, 255, 0.98);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 14px;
}

.logo-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--accent-color), var(--secondary-color));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.8rem;
}

.logo-text {
    font-size: 1.9rem;
    font-weight: 800;
    color: var(--dark-color);
}

.logo-text span {
    color: var(--accent-color);
}

nav ul {
    display: flex;
    list-style: none;
    gap: 2.5rem;
}

nav a {
    color: var(--dark-color);
    font-weight: 600;
    position: relative;
    text-decoration: none;
}

nav a:after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-color), var(--secondary-color));
    transition: var(--transition);
}

nav a:hover:after,
nav a.active:after {
    width: 100%;
}

/* 搜索区域 */
.search-section {
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    padding: 5rem 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.search-container {
    max-width: 900px;
    margin: 0 auto;
}

.search-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.search-header h3 {
    font-size: 2.2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.search-box {
    position: relative;
    margin-bottom: 2rem;
}

.search-input-container {
    display: flex;
    align-items: center;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
    border: 2px solid transparent;
    background: linear-gradient(white, white) padding-box,
                linear-gradient(135deg, var(--accent-color), var(--info-color)) border-box;
}

.search-icon {
    padding: 0 1.8rem;
    color: var(--accent-color);
    font-size: 1.4rem;
}

#searchInput {
    flex: 1;
    padding: 1.8rem 1.8rem 1.8rem 0;
    border: none;
    outline: none;
    font-size: 1.2rem;
    font-weight: 500;
    background: transparent;
}

#clearSearch {
    padding: 0 1.8rem;
    background: none;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    display: none;
    font-size: 1.4rem;
}

.search-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
}

.search-btn {
    padding: 1rem 2.5rem;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.8rem;
    transition: var(--transition);
}

.search-btn.secondary {
    background: linear-gradient(135deg, var(--info-color), #2563eb);
}

.search-btn:hover {
    transform: translateY(-3px);
}

.search-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 2rem;
}

.search-filter-btn {
    padding: 0.9rem 2rem;
    background: white;
    border: 2px solid var(--border-color);
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.7rem;
}

.search-filter-btn.active {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    color: white;
    border-color: var(--accent-color);
}

.search-stats {
    display: none;
    justify-content: space-between;
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.05), rgba(59, 130, 246, 0.05));
    border-radius: var(--border-radius);
    padding: 1.2rem 1.5rem;
    margin-top: 2rem;
}

.search-stats.visible {
    display: flex;
}

/* ========== 自动滚动过滤器核心样式（修复版） ========== */
/* 过滤器外层容器：左侧固定全部标准 + 右侧滚动区域 */
.filters-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    width: 100%;
    margin-bottom: 2.5rem;
    flex-wrap: nowrap;
}

/* 左侧固定的「全部标准」按钮 */
.all-standard-btn {
    padding: 0.9rem 2rem;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    color: white;
    border: 2px solid var(--accent-color);
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.7rem;
    flex-shrink: 0;
    white-space: nowrap;
}
.all-standard-btn:hover {
    transform: translateY(-3px);
    border-color: var(--accent-light);
}
.all-standard-btn.active {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    color: white;
    border-color: var(--accent-color);
}

/* 红框内的滚动容器（核心修复：加左右内边距，防止截断） */
.articles-filters {
    position: relative;
    flex: 1;
    overflow: hidden;
    /* 修复：左右内边距，给按钮边框预留显示空间，防止被截断 */
    padding: 0.6rem 1.2rem;
    /* 修复：垂直居中，避免按钮上下偏移 */
    display: flex;
    align-items: center;
}

/* 滚动内容包裹层：实现无缝滚动 */
.articles-filters .filters-scroll-wrapper {
    display: flex;
    gap: 1rem;
    width: max-content;
    animation: autoHorizontalScroll 25s linear infinite;
    will-change: transform;
    /* 修复：垂直居中 */
    align-items: center;
}

/* 鼠标悬停暂停滚动 */
.articles-filters:hover .filters-scroll-wrapper {
    animation-play-state: paused;
}

/* 自动横向滚动动画 */
@keyframes autoHorizontalScroll {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

/* 隐藏滚动条 */
.articles-filters::-webkit-scrollbar {
    display: none;
}
.articles-filters {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

/* 滚动容器内的标准按钮样式 */
.filter-btn {
    padding: 0.9rem 2rem;
    background: #ef960a;
    border: 2px solid #d97706;
    border-radius: 50px;
    font-weight: 600;
    color: #ffffff;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.7rem;
    flex-shrink: 0;
    white-space: nowrap;
}
.filter-btn i {
    color: #ffffff;
}
.filter-btn:hover {
    transform: translateY(-3px);
    border-color: var(--accent-light);
}
.filter-btn.active {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    color: white;
    border-color: var(--accent-color);
    /* 修复：激活样式优先级，确保边框完整显示 */
    z-index: 10;
}

/* ========== 全新卡片样式 ========== */
.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.article-card {
    background: #ffffff;
    border-radius: 20px;
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.2, 0, 0, 1);
    border: none;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.02);
    backdrop-filter: blur(0);
    display: flex;
    flex-direction: column;
    position: relative;
    min-height: 400px;
    background: linear-gradient(145deg, #ffffff, #fefefe);
}

/* 卡片顶部装饰条 */
.article-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-color), var(--secondary-color));
    transform: scaleX(1);
    transform-origin: left;
    transition: transform 0.4s ease;
}

/*.article-card:hover::before {
    transform: scaleX(1);
}*/

.article-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 35px -12px rgba(0, 0, 0, 0.15);
    border-color: transparent;
}

/* 卡片头部 */
.article-card-header {
    padding: 1.8rem 1.8rem 0.5rem;
}

/* 标准类型标签 - 更精致 */
.article-card-category {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.4rem 1rem;
    border-radius: 40px;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.3px;
    text-transform: uppercase;
    margin-bottom: 1.2rem;
    background: rgba(0, 0, 0, 0.03);
    border: none;
    backdrop-filter: blur(2px);
    transition: all 0.2s;
}

.article-card-category i {
    font-size: 0.85rem;
}

/* 各标准专属颜色 */
.article-card-category.asme {
    background: linear-gradient(135deg, rgba(220, 38, 38, 0.12), rgba(220, 38, 38, 0.05));
    color: var(--asme-color);
}
.article-card-category.astm {
    background: linear-gradient(135deg, rgba(26, 54, 93, 0.12), rgba(26, 54, 93, 0.05));
    color: var(--astm-color);
}
.article-card-category.gb {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.12), rgba(16, 185, 129, 0.05));
    color: var(--gb-color);
}
.article-card-category.en {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.12), rgba(59, 130, 246, 0.05));
    color: var(--en-color);
}
.article-card-category.as {
    background: linear-gradient(135deg, rgba(249, 115, 22, 0.12), rgba(249, 115, 22, 0.05));
    color: var(--as-color);
}
.article-card-category.other {
    background: linear-gradient(135deg, rgba(100, 116, 139, 0.12), rgba(100, 116, 139, 0.05));
    color: var(--text-light);
}

/* 文章标题 */
.article-card-title {
    font-size: 1.4rem;
    line-height: 1.35;
    margin-bottom: 0.8rem;
    font-weight: 700;
    color: var(--dark-color);
    height: auto;
    min-height: 3.8rem;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.article-card-title a {
    text-decoration: none;
    background: linear-gradient(120deg, currentColor, currentColor);
    background-repeat: no-repeat;
    background-size: 0% 2px;
    background-position: 0 100%;
    transition: background-size 0.2s;
}

.article-card-title a:hover {
    color: var(--accent-color);
    background-size: 100% 2px;
}

/* 卡片主体 */
.article-card-body {
    padding: 0 1.8rem 1rem;
    flex: 1;
}

.article-card-description {
    color: var(--text-light);
    font-size: 0.9rem;
    line-height: 1.6;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    margin-bottom: 0;
}

/* 底部元数据区域 */
.article-card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.8rem;
    background: var(--gray-color);
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    font-size: 0.8rem;
    color: var(--text-light);
    gap: 1rem;
    flex-wrap: wrap;
}

.article-card-path {
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.7rem;
    background: rgba(0, 0, 0, 0.04);
    padding: 0.25rem 0.6rem;
    border-radius: 20px;
    max-width: 180px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.article-card-date {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.75rem;
}

/* 操作按钮 - 核心修改 */
.article-card-actions {
    padding: 1rem 1.8rem;
    margin-top: auto;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%; /* 确保容器宽度 100%，让按钮完全撑开 */
}

.article-link-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    width: 100%; /* 强制宽度 100%，确保完全撑开 */
    padding: 0.8rem 1.2rem; /* 保留上下内边距，保证按钮点击区域 */
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    color: white;
    border-radius: 40px;
    font-weight: 600;
    font-size: 0.85rem;
    letter-spacing: 0.3px;
    text-decoration: none;
    transition: all 0.3s ease;
    border: none;
    box-shadow: 0 4px 8px rgba(245, 158, 11, 0.2);
}

.article-link-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(245, 158, 11, 0.3);
    background: linear-gradient(135deg, var(--accent-dark), var(--accent-color));
    color: white;
}

.article-link-btn i {
    transition: transform 0.2s;
}

.article-link-btn:hover i {
    transform: translateX(4px);
}

/* 响应式调整 */
@media (max-width: 768px) {
    .articles-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    .article-card {
        min-height: auto;
    }
    .article-card-title {
        font-size: 1.2rem;
        min-height: auto;
    }
    .article-card-meta {
        flex-direction: column;
        align-items: flex-start;
    }
    .article-card-path {
        max-width: 100%;
        white-space: normal;
        word-break: break-all;
    }
    /* 滚动过滤器移动端适配 */
    .filters-container {
        flex-direction: column;
        align-items: stretch;
        gap: 1rem;
    }
    .all-standard-btn {
        width: 100%;
        justify-content: center;
    }
    .articles-filters {
        width: 100%;
    }
    .filters-scroll-wrapper {
        animation-duration: 20s;
    }
}

/* 分页 */
.pagination-container {
    display: flex;
    justify-content: center;
    margin-top: 2rem;
}

.pagination {
    display: flex;
    gap: 0.5rem;
    align-items: center;
    flex-wrap: wrap;
}

.pagination-btn {
    padding: 0.7rem 1.3rem;
    border: 1px solid var(--border-color);
    background: white;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.pagination-btn.active {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    color: white;
    border-color: var(--accent-color);
}

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

/* 公司介绍 & 联系 */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.about-item {
    background: white;
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    border-left: 4px solid var(--accent-color);
}

.contact-simple {
    background: white;
    border-radius: var(--border-radius);
    padding: 3rem;
    max-width: 900px;
    margin: 0 auto;
    border-top: 4px solid var(--success-color);
}

.contact-info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.contact-info-item {
    text-align: center;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.03), rgba(245, 158, 11, 0.01));
    border: 1px solid rgba(245, 158, 11, 0.1);
}

.contact-info-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    color: white;
    font-size: 1.5rem;
}

/* Footer */
footer {
    background: linear-gradient(135deg, var(--primary-dark), #0a1a33);
    color: white;
    padding: 5rem 0 2.5rem;
    position: relative;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3.5rem;
    margin-bottom: 4rem;
}

.footer-section h3 {
    color: white;
    margin-bottom: 1.8rem;
    position: relative;
    padding-bottom: 1rem;
}

.footer-section h3:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 3px;
    background: var(--accent-color);
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.8rem;
}

.footer-section ul li a {
    color: #cbd5e0;
    text-decoration: none;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: var(--accent-color);
    padding-left: 5px;
}

.copyright {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #a0aec0;
}

/* 辅助组件 */
.spinner {
    border: 5px solid rgba(245, 158, 11, 0.1);
    border-top: 5px solid var(--accent-color);
    border-radius: 50%;
    width: 70px;
    height: 70px;
    animation: spin 1s linear infinite;
    margin: 0 auto 2rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.no-results {
    text-align: center;
    padding: 4rem 2rem;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.search-result-highlight {
    background-color: rgba(245, 158, 11, 0.3);
    border-radius: 3px;
    padding: 0 4px;
    font-weight: 600;
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out forwards;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式补充 */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 1rem;
    }
    nav ul {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }
    .about-grid {
        grid-template-columns: 1fr;
    }
 /* 新增：滚动锚点偏移，防止被固定头部遮挡 */
        #knowledge {
            scroll-margin-top: 100px;
        }
        /* 优化搜索统计区域出现时的平滑过渡 */
        .search-stats {
            transition: all 0.2s ease;
        }
        /* 确保搜索高亮样式醒目 */
        .search-result-highlight {
            background-color: #fef3c7;
            color: #b45309;
            font-weight: 600;
            padding: 0 2px;
            border-radius: 4px;
        }
}