/* ============================================
   速构科技官网 - 主样式表
   Mobile-first 响应式设计
   ============================================ */

/* ---- CSS Variables (Light Theme) ---- */
:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-primary-light: #dbeafe;
    --color-accent: #f59e0b;
    --color-wework: #07c160;

    --bg-body: #ffffff;
    --bg-card: #ffffff;
    --bg-light: #f8fafc;
    --bg-hover: #f1f5f9;
    --bg-input: #ffffff;
    --bg-dark: #1e293b;

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --text-inverse: #ffffff;

    --border: #e2e8f0;
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;

    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -2px rgba(0,0,0,0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.05);

    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;

    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;

    --container-max: 1200px;
    --header-height: 64px;
}

/* ---- Dark Theme ---- */
[data-theme="dark"] {
    --bg-body: #0f172a;
    --bg-card: #1e293b;
    --bg-light: #1e293b;
    --bg-hover: #334155;
    --bg-input: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --border: #334155;
    --border-light: #1e293b;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4);
}

/* ---- Reset & Base ---- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    color: var(--text-primary);
    background: var(--bg-body);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.2s;
}
a:hover { color: var(--color-primary-dark); }

img { max-width: 100%; height: auto; display: block; }

ul, ol { list-style: none; }

/* ---- Container ---- */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 1rem;
}

@media (min-width: 640px) { .container { padding: 0 1.5rem; } }
@media (min-width: 1024px) { .container { padding: 0 2rem; } }

/* ---- Buttons ---- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.6rem 1.25rem;
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
    line-height: 1.4;
    white-space: nowrap;
}
.btn:hover { text-decoration: none; }

.btn-primary {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}
.btn-primary:hover { background: var(--color-primary-dark); color: #fff; }

.btn-outline {
    background: transparent;
    color: var(--color-primary);
    border-color: var(--color-primary);
}
.btn-outline:hover { background: var(--color-primary); color: #fff; }

.btn-wework {
    background: var(--color-wework);
    color: #fff;
    border-color: var(--color-wework);
}
.btn-wework:hover { background: #06ad56; color: #fff; }

.btn-lg { padding: 0.8rem 2rem; font-size: 1rem; }
.btn-sm { padding: 0.4rem 1rem; font-size: 0.85rem; }
.btn-block { display: flex; width: 100%; }

.btn:disabled { opacity: 0.6; cursor: not-allowed; pointer-events: none; }

/* ---- Section ---- */
.section {
    padding: 3rem 0;
}
@media (min-width: 768px) { .section { padding: 5rem 0; } }

.bg-light { background: var(--bg-light); }

.section-header {
    text-align: center;
    margin-bottom: 2.5rem;
}
.section-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}
.section-header p {
    color: var(--text-secondary);
    font-size: 1rem;
}
@media (min-width: 768px) {
    .section-header h2 { font-size: 2rem; }
}

.section-footer {
    text-align: center;
    margin-top: 2rem;
}

/* ---- Page Hero ---- */
.page-hero {
    background: linear-gradient(135deg, var(--color-primary) 0%, #7c3aed 100%);
    color: #fff;
    padding: 3rem 0;
    text-align: center;
}
.page-hero-sm {
    padding: 2.5rem 0;
}
.page-hero h1 {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 0.75rem;
}
.page-hero p {
    font-size: 1.05rem;
    opacity: 0.9;
}
@media (min-width: 768px) {
    .page-hero { padding: 5rem 0; }
    .page-hero h1 { font-size: 2.5rem; }
}

/* ---- Breadcrumb ---- */
.breadcrumb {
    font-size: 0.85rem;
    margin-bottom: 0.75rem;
    opacity: 0.8;
}
.breadcrumb a { color: rgba(255,255,255,0.8); }
.breadcrumb a:hover { color: #fff; }
.breadcrumb span { color: rgba(255,255,255,0.6); }

/* ---- Header ---- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg-body);
    border-bottom: 1px solid var(--border);
    height: var(--header-height);
    display: flex;
    align-items: center;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}
.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}
.logo:hover { color: var(--color-primary); }
.logo-icon {
    color: var(--color-primary);
    font-size: 1.5rem;
}
.logo-img {
    max-width: 120px;
    max-height: 40px;
    object-fit: contain;
}

.main-nav ul {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}
.main-nav a {
    display: block;
    padding: 0.5rem 0.9rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all 0.2s;
    text-decoration: none;
}
.main-nav a:hover,
.main-nav a.active {
    color: var(--color-primary);
    background: var(--color-primary-light);
}
.nav-cta {
    background: var(--color-primary) !important;
    color: #fff !important;
    font-weight: 600 !important;
}
.nav-cta:hover { background: var(--color-primary-dark) !important; }

.has-submenu { position: relative; }
.main-nav ul.submenu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    min-width: 160px;
    padding: 0.5rem 0;
    z-index: 10;
}
.has-submenu:hover .submenu { display: block; }
.submenu a {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
    border-radius: 0;
    white-space: nowrap;
}

/* Mobile menu */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
    background: none;
    border: none;
    cursor: pointer;
}
.mobile-menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s;
}

@media (max-width: 1023px) {
    .main-nav {
        display: none;
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--bg-body);
        padding: 1rem;
        overflow-y: auto;
        z-index: 99;
    }
    .main-nav.open { display: block; }
    .main-nav ul {
        flex-direction: column;
        gap: 0;
    }
    .main-nav a {
        padding: 0.75rem 1rem;
        font-size: 1rem;
    }
    .submenu {
        position: static;
        box-shadow: none;
        border: none;
        padding-left: 1rem;
    }
    .has-submenu:hover .submenu { display: block; }
    .mobile-menu-toggle { display: flex; }
}

/* ==========================================
   HERO SECTION
   ========================================== */
.hero { position: relative; overflow: hidden; }

.hero-carousel { position: relative; }
.hero-slide {
    display: none;
    min-height: 420px;
    background-size: cover;
    background-position: center;
    position: relative;
}
.hero-slide.active { display: block; }
@media (min-width: 768px) { .hero-slide { min-height: 520px; } }
@media (min-width: 1024px) { .hero-slide { min-height: 600px; } }

.hero-overlay {
    background: linear-gradient(135deg, rgba(30,41,59,0.85) 0%, rgba(30,41,59,0.6) 100%);
    min-height: inherit;
    display: flex;
    align-items: center;
}
.hero-overlay .container { text-align: center; }

.hero-default {
    background: linear-gradient(135deg, var(--color-primary) 0%, #7c3aed 100%);
    padding: 5rem 0;
    text-align: center;
    color: #fff;
}
@media (min-width: 768px) { .hero-default { padding: 7rem 0; } }

.hero-title {
    font-size: 1.75rem;
    font-weight: 800;
    line-height: 1.3;
    color: #fff;
    margin-bottom: 1rem;
}
.hero-title span { color: var(--color-accent); display: block; font-size: 1.1rem; font-weight: 500; margin-top: 0.5rem; }
.hero-desc { font-size: 1rem; color: rgba(255,255,255,0.85); margin-bottom: 2rem; max-width: 600px; margin-left: auto; margin-right: auto; }
.hero-actions { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.hero-actions .btn { font-size: 0.95rem; padding: 0.7rem 1.5rem; }
.hero-actions .btn-outline { color: #fff; border-color: rgba(255,255,255,0.5); }
.hero-actions .btn-outline:hover { background: rgba(255,255,255,0.15); border-color: #fff; }

@media (min-width: 768px) {
    .hero-title { font-size: 2.5rem; }
    .hero-title span { font-size: 1.3rem; }
    .hero-desc { font-size: 1.1rem; }
}

/* Carousel controls */
.carousel-prev, .carousel-next {
    position: absolute; top: 50%; transform: translateY(-50%);
    background: rgba(255,255,255,0.2); color: #fff; border: none;
    width: 44px; height: 44px; border-radius: 50%; font-size: 1.3rem;
    cursor: pointer; transition: background 0.2s; z-index: 5;
}
.carousel-prev:hover, .carousel-next:hover { background: rgba(255,255,255,0.4); }
.carousel-prev { left: 1rem; }
.carousel-next { right: 1rem; }
.carousel-dots { position: absolute; bottom: 1.5rem; left: 50%; transform: translateX(-50%); display: flex; gap: 0.5rem; }
.dot { width: 10px; height: 10px; border-radius: 50%; background: rgba(255,255,255,0.4); cursor: pointer; transition: all 0.2s; }
.dot.active { background: #fff; width: 24px; border-radius: 5px; }

/* ==========================================
   SERVICE CARDS
   ========================================== */
.services-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}
@media (min-width: 640px) {
    .services-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1024px) {
    .services-grid { grid-template-columns: repeat(4, 1fr); }
}

.service-card {
    display: block;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
    transition: all 0.3s;
    color: var(--text-primary);
    text-decoration: none;
    position: relative;
    overflow: hidden;
}
.service-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
    color: var(--text-primary);
}
.service-icon { font-size: 2.5rem; margin-bottom: 0.75rem; }
.service-card h3 { font-size: 1.1rem; font-weight: 600; margin-bottom: 0.5rem; }
.service-card p { font-size: 0.85rem; color: var(--text-secondary); line-height: 1.5; margin-bottom: 0.75rem; }
.service-tags { font-size: 0.75rem; color: var(--text-muted); }

.card-highlight {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 1px var(--color-primary), var(--shadow-md);
}
.card-badge {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    background: var(--color-accent);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.2rem 0.5rem;
    border-radius: 999px;
}

/* ==========================================
   LLM PREVIEW SECTION
   ========================================== */
.llm-preview-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    align-items: center;
}
@media (min-width: 768px) {
    .llm-preview-grid { grid-template-columns: 1fr 1fr; }
}

.llm-preview-content h2 { font-size: 1.75rem; margin-bottom: 1rem; }
.llm-preview-content > p { color: var(--text-secondary); margin-bottom: 1.5rem; }
.llm-features { margin-bottom: 1.5rem; }
.llm-features li {
    padding: 0.5rem 0;
    font-size: 0.95rem;
    color: var(--text-secondary);
}
.llm-preview-actions { display: flex; gap: 1rem; flex-wrap: wrap; }

.llm-demo-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}
.llm-demo-header {
    background: var(--color-primary);
    color: #fff;
    padding: 0.75rem 1rem;
    font-weight: 600;
    font-size: 0.95rem;
}
.llm-demo-body { padding: 1rem; display: flex; flex-direction: column; gap: 0.75rem; }
.demo-msg {
    padding: 0.6rem 0.8rem;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    line-height: 1.5;
}
.demo-msg.user {
    background: var(--bg-hover);
    align-self: flex-end;
    max-width: 85%;
}
.demo-msg.ai {
    background: var(--color-primary-light);
    max-width: 90%;
}

/* ==========================================
   CASES GRID
   ========================================== */
.cases-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}
@media (min-width: 640px) {
    .cases-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1024px) {
    .cases-grid { grid-template-columns: repeat(3, 1fr); }
}

.case-card {
    display: block;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all 0.3s;
    color: var(--text-primary);
    text-decoration: none;
}
.case-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    color: var(--text-primary);
}
.case-img {
    position: relative;
    height: 180px;
    background: var(--bg-hover);
    overflow: hidden;
}
.case-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.case-img-placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    font-size: 3rem;
    color: var(--text-muted);
}
.case-cat {
    position: absolute;
    top: 0.75rem;
    left: 0.75rem;
    background: var(--color-primary);
    color: #fff;
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
    border-radius: 999px;
}
.case-info { padding: 1rem; }
.case-info h3 { font-size: 1rem; font-weight: 600; margin-bottom: 0.4rem; }
.case-info > p { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 0.5rem; }
.case-client { font-size: 0.8rem; color: var(--text-muted); }
.case-tech-tags { margin-top: 0.5rem; display: flex; flex-wrap: wrap; gap: 0.3rem; }

/* ==========================================
   ARTICLES
   ========================================== */
.articles-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}
@media (min-width: 640px) {
    .articles-grid { grid-template-columns: repeat(2, 1fr); }
}

.article-card {
    display: block;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all 0.3s;
    color: var(--text-primary);
    text-decoration: none;
}
.article-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    color: var(--text-primary);
}
.article-img {
    height: 160px;
    overflow: hidden;
}
.article-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.article-info { padding: 1rem; }
.article-cat {
    display: inline-block;
    background: var(--color-primary-light);
    color: var(--color-primary);
    font-size: 0.75rem;
    font-weight: 500;
    padding: 0.15rem 0.5rem;
    border-radius: 999px;
    margin-bottom: 0.5rem;
}
.article-info h3 { font-size: 1rem; font-weight: 600; margin-bottom: 0.4rem; }
.article-info > p { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 0.5rem; }
.article-info time { font-size: 0.8rem; color: var(--text-muted); }

/* ==========================================
   WEWORK CTA
   ========================================== */
.wework-cta-section {
    background: linear-gradient(135deg, #07c160 0%, #06ad56 100%);
    color: #fff;
}
.wework-cta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
    flex-wrap: wrap;
}
.wework-cta-content h2 { font-size: 1.5rem; margin-bottom: 0.75rem; }
.wework-cta-content p { opacity: 0.9; margin-bottom: 1.5rem; font-size: 1rem; }
.wework-cta-qr { text-align: center; }
.wework-cta-qr img { border-radius: var(--radius-md); border: 3px solid #fff; }
.wework-cta-qr p { margin-top: 0.5rem; font-size: 0.85rem; opacity: 0.85; }

/* ==========================================
   FILTER BAR
   ========================================== */
.filter-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2rem;
    justify-content: center;
}
.filter-btn {
    padding: 0.5rem 1rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 0.85rem;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all 0.2s;
}
.filter-btn:hover { border-color: var(--color-primary); color: var(--color-primary); }
.filter-btn.active {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}
.filter-count { font-size: 0.8rem; opacity: 0.7; }

/* ==========================================
   PAGINATION
   ========================================== */
.pagination { margin-top: 2rem; display: flex; justify-content: center; }
.pagination ul { display: flex; gap: 0.25rem; align-items: center; }
.pagination li { list-style: none; }
.pagination a, .pagination span {
    display: flex; align-items: center; justify-content: center;
    min-width: 36px; height: 36px; padding: 0 0.5rem;
    border-radius: var(--radius-sm); font-size: 0.9rem;
    border: 1px solid var(--border); color: var(--text-secondary);
    text-decoration: none; transition: all 0.2s;
}
.pagination a:hover { border-color: var(--color-primary); color: var(--color-primary); }
.pagination span.active { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }
.pagination span.disabled { opacity: 0.4; cursor: not-allowed; }
.pagination span.ellipsis { border: none; }

/* ==========================================
   ARTICLES LIST PAGE
   ========================================== */
.articles-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}
@media (min-width: 768px) {
    .articles-layout { grid-template-columns: 1fr 280px; }
}

.article-list-item {
    display: flex;
    gap: 1rem;
    padding: 1.25rem 0;
    border-bottom: 1px solid var(--border);
    flex-direction: column;
}
@media (min-width: 640px) {
    .article-list-item { flex-direction: row; }
}
.article-list-img {
    flex-shrink: 0;
    width: 100%;
    height: 160px;
    border-radius: var(--radius-md);
    overflow: hidden;
}
@media (min-width: 640px) {
    .article-list-img { width: 200px; height: 140px; }
}
.article-list-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.article-list-body h2 { font-size: 1.1rem; margin-bottom: 0.4rem; }
.article-list-body h2 a { color: var(--text-primary); }
.article-list-body h2 a:hover { color: var(--color-primary); }
.article-list-body > p { font-size: 0.9rem; color: var(--text-secondary); }
.article-list-meta {
    display: flex;
    gap: 1rem;
    align-items: center;
    margin-bottom: 0.5rem;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.articles-sidebar { display: flex; flex-direction: column; gap: 1.5rem; }

/* Sidebar Widget */
.sidebar-widget {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
}
.sidebar-widget h3 { font-size: 1rem; font-weight: 600; margin-bottom: 1rem; padding-bottom: 0.75rem; border-bottom: 1px solid var(--border); }
.sidebar-cta { text-align: center; background: var(--color-primary); color: #fff; border-color: var(--color-primary); }
.sidebar-cta h3 { border-bottom-color: rgba(255,255,255,0.2); }
.sidebar-cta .btn { margin-top: 0.75rem; }

.popular-list li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}
.popular-list li:last-child { border-bottom: none; }
.popular-list a { color: var(--text-primary); flex: 1; }
.popular-list a:hover { color: var(--color-primary); }
.popular-views { font-size: 0.8rem; color: var(--text-muted); white-space: nowrap; }

/* ==========================================
   CASE DETAIL
   ========================================== */
.case-detail-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}
@media (min-width: 768px) {
    .case-detail-layout { grid-template-columns: 1fr 280px; }
}

.case-meta {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
    font-size: 0.9rem;
    opacity: 0.85;
}
.case-cat-badge {
    background: rgba(255,255,255,0.2);
    padding: 0.15rem 0.6rem;
    border-radius: 999px;
    font-size: 0.8rem;
}
.case-cover {
    border-radius: var(--radius-lg);
    overflow: hidden;
    margin-bottom: 1.5rem;
}
.case-cover img { width: 100%; }
.case-body {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-primary);
}
.case-body img { border-radius: var(--radius-md); margin: 1rem 0; }
.case-body p { margin-bottom: 1rem; }
.case-body h2, .case-body h3 { margin: 1.5rem 0 0.75rem; }
.case-tech-section { margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid var(--border); }
.case-tech-section h3 { font-size: 1.1rem; margin-bottom: 0.75rem; }

.related-list { display: flex; flex-direction: column; gap: 0.75rem; }
.related-item {
    display: flex;
    gap: 0.75rem;
    align-items: center;
    color: var(--text-primary);
}
.related-item:hover { color: var(--color-primary); }
.related-item img {
    width: 60px; height: 48px; border-radius: var(--radius-sm); object-fit: cover; flex-shrink: 0;
}
.related-item h4 { font-size: 0.85rem; font-weight: 500; margin-bottom: 0.2rem; }

/* ==========================================
   ARTICLE DETAIL
   ========================================== */
.article-detail-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}
@media (min-width: 768px) {
    .article-detail-layout { grid-template-columns: 1fr 280px; }
}
.article-meta {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
    font-size: 0.9rem;
    opacity: 0.85;
}
.article-cover {
    border-radius: var(--radius-lg);
    overflow: hidden;
    margin-bottom: 1.5rem;
}
.article-cover img { width: 100%; }
.article-body {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-primary);
}
.article-body img { border-radius: var(--radius-md); margin: 1rem 0; max-width: 100%; }
.article-body p { margin-bottom: 1rem; }
.article-body h2, .article-body h3 { margin: 1.5rem 0 0.75rem; }
.article-body pre { background: var(--bg-hover); border-radius: var(--radius-md); padding: 1rem; overflow-x: auto; font-size: 0.9rem; margin: 1rem 0; }
.article-body code { font-family: var(--font-mono); font-size: 0.9em; background: var(--bg-hover); padding: 0.1rem 0.3rem; border-radius: 3px; }
.article-body pre code { background: none; padding: 0; }
.article-body blockquote {
    border-left: 4px solid var(--color-primary);
    padding-left: 1rem;
    color: var(--text-secondary);
    margin: 1rem 0;
}
.article-body table { width: 100%; border-collapse: collapse; margin: 1rem 0; }
.article-body th, .article-body td { border: 1px solid var(--border); padding: 0.5rem 0.75rem; font-size: 0.9rem; }
.article-body th { background: var(--bg-hover); font-weight: 600; }

/* ==========================================
   ABOUT PAGE
   ========================================== */
.about-content { max-width: 800px; margin: 0 auto; }
.about-intro h2 { font-size: 1.5rem; margin-bottom: 1rem; }
.about-intro p { color: var(--text-secondary); margin-bottom: 1rem; font-size: 1rem; line-height: 1.8; }

.about-highlights {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin-top: 2.5rem;
}
@media (min-width: 640px) {
    .about-highlights { grid-template-columns: repeat(4, 1fr); }
}
.highlight-item {
    text-align: center;
    padding: 1.5rem 1rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}
.highlight-num {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: var(--color-primary);
}
.highlight-label { font-size: 0.9rem; color: var(--text-secondary); margin-top: 0.25rem; display: block; }

/* Timeline */
.timeline {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
    padding-left: 2rem;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 0.5rem;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
}
.timeline-item {
    position: relative;
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
}
.timeline-item::before {
    content: '';
    position: absolute;
    left: -1.75rem;
    top: 0.25rem;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-primary);
    border: 3px solid var(--bg-light);
}
.timeline-year {
    font-size: 0.85rem;
    color: var(--color-primary);
    font-weight: 600;
    margin-bottom: 0.25rem;
}
.timeline-content h3 { font-size: 1.05rem; margin-bottom: 0.25rem; }
.timeline-content p { font-size: 0.9rem; color: var(--text-secondary); }

/* Team */
.team-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}
@media (min-width: 768px) {
    .team-grid { grid-template-columns: repeat(4, 1fr); }
}
.team-card {
    text-align: center;
    padding: 1.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}
.team-avatar { font-size: 3rem; margin-bottom: 0.75rem; }
.team-card h3 { font-size: 1rem; font-weight: 600; }
.team-role { font-size: 0.8rem; color: var(--color-primary); display: block; margin-bottom: 0.5rem; }
.team-card p { font-size: 0.85rem; color: var(--text-secondary); }

/* Honors */
.honors-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}
@media (min-width: 640px) {
    .honors-grid { grid-template-columns: repeat(4, 1fr); }
}
.honor-item {
    text-align: center;
    padding: 1.5rem 1rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}
.honor-icon { font-size: 2rem; display: block; margin-bottom: 0.5rem; }
.honor-item h3 { font-size: 0.9rem; color: var(--text-secondary); }

/* ==========================================
   SERVICES DETAIL PAGE
   ========================================== */
.services-detail-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}
@media (min-width: 768px) {
    .services-detail-grid { grid-template-columns: repeat(2, 1fr); }
}

.service-detail-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    position: relative;
}
.service-detail-card .card-badge { position: absolute; top: 1rem; right: 1rem; }
.sd-icon { font-size: 2.5rem; margin-bottom: 0.75rem; }
.service-detail-card h2 { font-size: 1.2rem; margin-bottom: 0.5rem; }
.sd-desc { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 1rem; }
.sd-tech { margin-bottom: 1rem; }
.sd-tech h4, .sd-scenarios h4 { font-size: 0.85rem; margin-bottom: 0.5rem; color: var(--text-secondary); }
.sd-scenarios ul { padding-left: 1.2rem; }
.sd-scenarios li { list-style: disc; font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 0.3rem; }
.sd-actions { display: flex; gap: 0.75rem; flex-wrap: wrap; margin-top: 1rem; }

.tags { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.tags span {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    background: var(--bg-hover);
    border-radius: 999px;
    font-size: 0.75rem;
    color: var(--text-secondary);
}
.mini-tag {
    display: inline-block;
    padding: 0.1rem 0.4rem;
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-radius: 999px;
    font-size: 0.7rem;
}

/* Service Detail Single Page */
.service-detail-layout { max-width: 800px; margin: 0 auto; }
.sd-section { margin-bottom: 2rem; }
.sd-section h3 { font-size: 1.2rem; margin-bottom: 0.75rem; }
.scenario-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 0.75rem; }
.scenario-item { display: flex; gap: 0.75rem; align-items: flex-start; padding: 0.75rem; background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-md); }
.scenario-num { color: var(--color-primary); font-weight: 700; font-size: 1.1rem; flex-shrink: 0; }
.scenario-item p { font-size: 0.85rem; color: var(--text-secondary); }
.features-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 0.5rem; }
.feature-item { padding: 0.5rem 0.75rem; background: var(--bg-hover); border-radius: var(--radius-md); font-size: 0.85rem; }

.sd-cta {
    text-align: center;
    padding: 2rem;
    background: var(--color-primary-light);
    border-radius: var(--radius-lg);
}
.sd-contact {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
}
.sd-contact h3 { margin-bottom: 0.5rem; }
.sd-contact > p { color: var(--text-secondary); margin-bottom: 1rem; font-size: 0.9rem; }

/* ==========================================
   CONTACT PAGE
   ========================================== */
.contact-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}
@media (min-width: 768px) {
    .contact-layout { grid-template-columns: 360px 1fr; }
}

.contact-info-col { display: flex; flex-direction: column; gap: 1rem; }
.contact-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    text-align: center;
}
.contact-icon { font-size: 1.5rem; margin-bottom: 0.5rem; }
.contact-card h3 { font-size: 0.95rem; margin-bottom: 0.25rem; }
.contact-value { font-size: 1rem; font-weight: 600; color: var(--color-primary); }
.contact-note { font-size: 0.8rem; color: var(--text-muted); margin-top: 0.25rem; }
.contact-qr { margin: 0.5rem 0; }
.contact-qr img { margin: 0 auto; border-radius: var(--radius-md); }

.contact-form-col h2 { font-size: 1.5rem; margin-bottom: 0.5rem; }
.contact-form-col > p { color: var(--text-secondary); margin-bottom: 1.5rem; }

/* Forms */
.contact-form { max-width: 600px; }
.form-group { margin-bottom: 1rem; }
.form-group label { display: block; font-size: 0.9rem; font-weight: 500; margin-bottom: 0.3rem; color: var(--text-primary); }
.required { color: #e53e3e; }
.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.6rem 0.8rem;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-family: inherit;
    color: var(--text-primary);
    outline: none;
    transition: border-color 0.2s;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; margin-bottom: 20px;}
@media (max-width: 480px) { .form-row { grid-template-columns: 1fr; } }

.ajax-form button[type="submit"] { margin-top: 0.5rem; }

.captcha-row {
    display: grid;
    grid-template-columns: 110px minmax(0, 1fr);
    gap: 0.75rem;
    align-items: center;
}

.captcha-question {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 42px;
    padding: 0 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-light);
    color: var(--text-primary);
    font-weight: 700;
    white-space: nowrap;
}

.captcha-compact {
    margin-top: 0;
}

.captcha-compact .captcha-row {
    grid-template-columns: 96px minmax(0, 1fr);
}

.captcha-compact .captcha-question {
    min-height: 38px;
    font-size: 0.85rem;
}

.consult-form .captcha-group {
    margin-bottom: 0;
}

.consult-form .captcha-row {
    grid-template-columns: 90px minmax(0, 1fr);
    gap: 0.5rem;
}

.map-container { border-radius: var(--radius-lg); overflow: hidden; }
.map-placeholder {
    background: var(--bg-hover);
    height: 350px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
}
.map-note { font-size: 0.85rem; color: var(--text-muted); margin-top: 0.5rem; }

/* ==========================================
   FOOTER
   ========================================== */
.site-footer {
    background: var(--bg-dark);
    color: #cbd5e1;
    padding: 3rem 0 0;
}
.footer-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}
@media (min-width: 768px) {
    .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; }
}
.footer-col h3 { font-size: 1.1rem; color: #fff; margin-bottom: 1rem; }
.footer-col h4 { font-size: 0.95rem; color: #fff; margin-bottom: 0.75rem; }
.footer-col p { font-size: 0.85rem; line-height: 1.6; margin-bottom: 0.75rem; }
.footer-col ul { display: flex; flex-direction: column; gap: 0.5rem; }
.footer-col ul a { color: #94a3b8; font-size: 0.85rem; }
.footer-col ul a:hover { color: #fff; }
.footer-contact-info p { font-size: 0.85rem; }
.footer-qr { text-align: center; }
.footer-qr img { margin: 0 auto; border-radius: var(--radius-md); border: 2px solid rgba(255,255,255,0.1); }
.footer-qr p { font-size: 0.8rem; color: #94a3b8; margin-top: 0.4rem; }

.footer-bottom {
    margin-top: 2rem;
    padding: 1.25rem 0;
    border-top: 1px solid rgba(255,255,255,0.1);
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.5rem;
    font-size: 0.8rem;
    color: #64748b;
}
.footer-bottom a { color: #64748b; }
.footer-bottom a:hover { color: #fff; }

/* ==========================================
   FLOATING CONSULT
   ========================================== */
.floating-consult {
    position: fixed;
    bottom: 5rem;
    right: 2rem;
    z-index: 90;
}
@media (max-width: 640px) {
    .floating-consult { bottom: 5rem; right: 1rem; }
}
.consult-btn {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--color-primary);
    color: #fff;
    border: none;
    box-shadow: 0 4px 12px rgba(37,99,235,0.4);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    transition: all 0.3s;
    position: relative;
}
.consult-btn:hover { transform: scale(1.1); }
.consult-text { display: none; }

.consult-popup {
    display: none;
    position: absolute;
    bottom: 70px;
    right: 0;
    width: 320px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}
.consult-popup.open { display: block; }
.consult-popup-inner { padding: 1.25rem; position: relative; }
.popup-close {
    position: absolute;
    top: 0.5rem;
    right: 0.75rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-muted);
    line-height: 1;
}
.consult-popup-inner h4 { font-size: 1rem; margin-bottom: 1rem; }
.consult-form { display: flex; flex-direction: column; gap: 0.6rem; }
.consult-form input,
.consult-form select,
.consult-form textarea {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-family: inherit;
    background: var(--bg-input);
    color: var(--text-primary);
    outline: none;
}
.consult-form input:focus,
.consult-form select:focus,
.consult-form textarea:focus {
    border-color: var(--color-primary);
}
.consult-or {
    text-align: center;
    margin: 0.75rem 0;
    position: relative;
}
.consult-or::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    border-top: 1px solid var(--border);
}
.consult-or span {
    position: relative;
    background: var(--bg-card);
    padding: 0 0.75rem;
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ==========================================
   MOBILE STICKY BAR
   ========================================== */
.mobile-sticky-bar {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    z-index: 90;
    grid-template-columns: repeat(3, 1fr);
}
@media (max-width: 640px) {
    .mobile-sticky-bar { display: grid; }
}
.sticky-item {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.3rem;
    padding: 0.75rem 0.5rem;
    font-size: 0.8rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    border: none;
    background: none;
    color: var(--text-primary);
    transition: background 0.2s;
}
.sticky-item:hover { background: var(--bg-hover); }
.sticky-phone { background: var(--color-primary); color: #fff; }
.sticky-phone:hover { background: var(--color-primary-dark); color: #fff; }
.sticky-wework { background: var(--color-wework); color: #fff; }
.sticky-wework:hover { background: #06ad56; color: #fff; }

/* ==========================================
   TOAST
   ========================================== */
.toast {
    display: none;
    position: fixed;
    top: 1rem;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-dark);
    color: #fff;
    padding: 0.75rem 1.5rem;
    border-radius: 999px;
    font-size: 0.9rem;
    z-index: 200;
    box-shadow: var(--shadow-lg);
    animation: toastIn 0.3s ease;
}
.toast.show { display: block; }
.toast.success { background: #16a34a; }
.toast.error { background: #dc2626; }
@keyframes toastIn {
    from { opacity: 0; transform: translateX(-50%) translateY(-20px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* ==========================================
   ERROR PAGE
   ========================================== */
.error-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 60vh;
    text-align: center;
}
.error-page h1 {
    font-size: 6rem;
    font-weight: 800;
    color: var(--color-primary);
    line-height: 1;
    margin-bottom: 0.5rem;
}
.error-page p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* ==========================================
   EMPTY / LOADING STATES
   ========================================== */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-muted);
    font-size: 1rem;
    grid-column: 1 / -1;
}

/* ==========================================
   DARK MODE
   ========================================== */
html.dark {
    --color-primary: #818cf8;
    --color-primary-dark: #6366f1;
    --color-primary-light: #a5b4fc;
    --bg-body: #0f172a;
    --bg-card: #1e293b;
    --bg-dark: #020617;
    --bg-light: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: #334155;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 10px 30px rgba(0,0,0,0.5);
}

html.dark .site-header {
    background: rgba(15, 23, 42, 0.95);
    border-bottom-color: var(--border-color);
}
html.dark .site-header.scrolled {
    box-shadow: 0 2px 8px rgba(0,0,0,0.4);
}
html.dark .main-nav a:hover,
html.dark .main-nav a.active {
    color: var(--color-primary-light);
}
html.dark .main-nav a::after {
    background: var(--color-primary-light);
}
html.dark .submenu {
    background: var(--bg-card);
    border-color: var(--border-color);
}
html.dark .service-card,
html.dark .case-card,
html.dark .article-list-item,
html.dark .team-card,
html.dark .honor-item,
html.dark .highlight-item {
    background: var(--bg-card);
    border-color: var(--border-color);
}
html.dark .form-input,
html.dark .form-textarea,
html.dark .form-select {
    background: var(--bg-dark);
    border-color: var(--border-color);
    color: var(--text-primary);
}
html.dark .form-input:focus,
html.dark .form-textarea:focus,
html.dark .form-select:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(129,140,248,0.15);
}
html.dark .btn-outline {
    border-color: var(--color-primary);
    color: var(--color-primary);
}
html.dark .btn-outline:hover {
    background: var(--color-primary);
    color: #fff;
}
html.dark .timeline::before {
    background: var(--border-color);
}
html.dark .timeline-content {
    background: var(--bg-card);
    border-color: var(--border-color);
}
html.dark .consult-popup {
    background: var(--bg-card);
    border-color: var(--border-color);
}
html.dark .toast {
    background: var(--bg-card);
}

/* ==========================================
   DARK MODE TOGGLE BUTTON
   ========================================== */
.dark-mode-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border: 1.5px solid var(--border-color);
    border-radius: 50%;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    margin-left: 0.5rem;
    flex-shrink: 0;
}
.dark-mode-toggle:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
    background: rgba(79, 70, 229, 0.08);
}
.dark-mode-toggle .icon-moon { display: none; }
html.dark .dark-mode-toggle .icon-sun { display: none; }
html.dark .dark-mode-toggle .icon-moon { display: block; }

@media (max-width: 1023px) {
    .dark-mode-toggle {
        position: fixed;
        bottom: 5.5rem;
        right: 1.5rem;
        width: 44px;
        height: 44px;
        border-radius: 50%;
        background: var(--color-primary);
        color: #fff;
        border: none;
        box-shadow: var(--shadow-lg);
        z-index: 90;
        margin: 0;
    }
    .dark-mode-toggle:hover {
        background: var(--color-primary-dark);
        color: #fff;
    }
}

/* ==========================================
   SCROLL ANIMATIONS
   ========================================== */
.fade-in,
.slide-up,
.slide-left,
.slide-right {
    opacity: 0;
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.slide-up { transform: translateY(30px); }
.slide-left { transform: translateX(-30px); }
.slide-right { transform: translateX(30px); }

.fade-in.visible,
.slide-up.visible,
.slide-left.visible,
.slide-right.visible {
    opacity: 1;
    transform: none;
}

/* 给主要区块自动添加动画类 */
.section > .container > .section-header,
.home-services .service-card,
.home-cases .case-card,
.team-grid .team-card,
.about-highlights .highlight-item,
.honors-grid .honor-item {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}
.section > .container > .section-header.visible,
.home-services .service-card.visible,
.home-cases .case-card.visible,
.team-grid .team-card.visible,
.about-highlights .highlight-item.visible,
.honors-grid .honor-item.visible {
    opacity: 1;
    transform: none;
}

/*  stagger 延迟（手动在 HTML 里加 .delay-1 等） */
.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }
.delay-5 { transition-delay: 0.5s; }

/* ==========================================
   CARD HOVER ENHANCEMENT
   ========================================== */
.service-card {
    transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}
.service-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.case-card {
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.case-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}
.case-card:hover .case-img img {
    transform: scale(1.05);
}
.case-img img {
    transition: transform 0.4s ease;
}

.article-list-item {
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.article-list-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.team-card {
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.team-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.stat-card {
    transition: transform 0.2s ease;
}
.stat-card:hover {
    transform: scale(1.02);
}

/* ==========================================
   BACK TO TOP BUTTON
   ========================================== */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--color-primary);
    color: #fff;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
    z-index: 90;
}
.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-to-top:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
}

@media (max-width: 767px) {
    .back-to-top {
        bottom: 5.5rem;
        right: 1.5rem;
        width: 44px;
        height: 44px;
    }
}

/* ==========================================
   MOBILE MENU SMOOTH ANIMATION
   ========================================== */
@media (max-width: 1023px) {
    .main-nav {
        position: fixed;
        top: 0;
        right: 0;
        width: 280px;
        height: 100vh;
        background: var(--bg-card);
        box-shadow: -4px 0 20px rgba(0,0,0,0.15);
        transform: translateX(100%);
        transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        z-index: 1000;
        padding: 5rem 1.5rem 2rem;
        overflow-y: auto;
    }
    .main-nav.open {
        transform: translateX(0);
    }
    .main-nav::before {
        content: '';
        position: fixed;
        inset: 0;
        background: rgba(0,0,0,0.4);
        opacity: 0;
        visibility: hidden;
        transition: opacity 0.3s ease, visibility 0.3s;
        z-index: -1;
    }
    .main-nav.open::before {
        opacity: 1;
        visibility: visible;
    }
    .main-nav ul {
        flex-direction: column;
        gap: 0;
    }
    .main-nav li {
        border-bottom: 1px solid var(--border-color);
    }
    .main-nav a {
        display: block;
        padding: 0.75rem 0;
        font-size: 1rem;
    }
    .submenu {
        position: static;
        box-shadow: none;
        border: none;
        padding-left: 1rem;
        background: transparent;
    }
    .submenu a {
        font-size: 0.9rem;
        color: var(--text-secondary);
    }
    .mobile-menu-toggle.open span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    .mobile-menu-toggle.open span:nth-child(2) {
        opacity: 0;
    }
    .mobile-menu-toggle.open span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }
}
@media (min-width: 1024px) {
    .main-nav {
        position: static !important;
        transform: none !important;
        width: auto !important;
        height: auto !important;
        background: transparent !important;
        box-shadow: none !important;
        padding: 0 !important;
    }
}

/* ==========================================
   HERO CAROUSEL ENHANCEMENT
   ========================================== */
.hero-slide {
    transition: opacity 0.8s ease;
}
.carousel-dots .dot {
    transition: background 0.3s ease, transform 0.2s ease;
}
.carousel-dots .dot:hover {
    transform: scale(1.3);
}
.carousel-next,
.carousel-prev {
    transition: background 0.2s ease, transform 0.2s ease;
}
.carousel-next:hover,
.carousel-prev:hover {
    background: rgba(0,0,0,0.6);
    transform: scale(1.05);
}

/* ==========================================
   FRIENDLY 404 PAGE
   ========================================== */
.error-page {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 70vh;
    text-align: center;
    padding: 2rem;
}
.error-page .error-code {
    font-size: 8rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin-bottom: 0.5rem;
}
.error-page .error-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}
.error-page .error-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 400px;
}
.error-page .error-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

@media (max-width: 767px) {
    .error-page .error-code {
        font-size: 5rem;
    }
    .error-page .error-title {
        font-size: 1.2rem;
    }
}

/* ==========================================
   SITE SEARCH (浮动按钮 + 面板)
   ========================================== */
.search-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border: 1.5px solid var(--border-color);
    border-radius: 50%;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    margin-left: 0.25rem;
    flex-shrink: 0;
}
.search-toggle:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
}
.search-panel {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 2000;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding-top: 10vh;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s;
}
.search-panel.open {
    opacity: 1;
    visibility: visible;
}
.search-box {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 2rem;
    width: 90%;
    max-width: 560px;
    box-shadow: var(--shadow-lg);
    transform: translateY(-20px);
    transition: transform 0.3s ease;
}
.search-panel.open .search-box {
    transform: translateY(0);
}
.search-box h3 {
    margin-bottom: 1rem;
    font-size: 1.1rem;
}
.search-box .form-input {
    font-size: 1rem;
    padding: 0.75rem 1rem;
}
.search-results {
    margin-top: 1rem;
    max-height: 300px;
    overflow-y: auto;
}
.search-result-item {
    display: block;
    padding: 0.75rem;
    border-radius: var(--radius);
    transition: background 0.15s;
    text-decoration: none;
    color: var(--text-primary);
}
.search-result-item:hover {
    background: var(--bg-light);
}
.search-result-item h4 {
    font-size: 0.95rem;
    margin-bottom: 0.25rem;
}
.search-result-item p {
    font-size: 0.8rem;
    color: var(--text-muted);
}
.search-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-muted);
}

@media (max-width: 1023px) {
    .search-toggle { display: none; }
}

/* ==========================================
   ACCESSIBILITY IMPROVEMENTS
   ========================================== */
:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* 屏幕阅读器专用 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    white-space: nowrap;
    border: 0;
}

/* 减少动画（用户设置） */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    .fade-in,
    .slide-up,
    .slide-left,
    .slide-right {
        opacity: 1 !important;
        transform: none !important;
    }
}

/* ==========================================
   IMAGE LAZY LOADING (原生)
   ========================================== */
img[loading="lazy"] {
    /*opacity: 0;*/
    transition: opacity 0.4s ease;
}
img[loading="lazy"].loaded {
    opacity: 1;
}

/* 适配 prefers-color-scheme（无本地存储时） */
@media (prefers-color-scheme: dark) {
    html:not([class*="dark"]) {
        /* 仅当没有手动设置时才跟系统 */
    }
}