:root {
    --color-primary: #3b82f6;
    --color-primary-dark: #1e40af;
    --color-accent: #38bdf8;
    --color-surface: #f1f5f9;
    --color-text: #1e293b;
    --rgb-primary: 59,130,246;
    --rgb-accent: 56,189,248;
    --radius-sm: 2px;
    --radius-md: 6px;
    --radius-lg: 10px;
    --radius-xl: 14px;
    --shadow-sm: 0 1px 2px rgba(15,23,42,.08), 0 1px 1px rgba(15,23,42,.04);
    --shadow-md: inset 0 1px 0 rgba(255,255,255,.8), 0 8px 16px -6px rgba(15,23,42,.14), 0 3px 6px -4px rgba(15,23,42,.08);
    --shadow-lg: inset 0 1px 0 rgba(255,255,255,.9), 0 24px 40px -12px rgba(15,23,42,.22), 0 6px 12px -6px rgba(15,23,42,.1);
    --space-section: 3.5rem;
    --space-card: 1.25rem;
    --space-gap: 1rem;
    --transition: 0.55s cubic-bezier(0.22, 1, 0.36, 1);
    --heading-weight: 800;
    --body-line-height: 1.75;
}

/* 基础覆盖 */
body {
    color: var(--color-text);
    line-height: var(--body-line-height);
    background: linear-gradient(180deg, #f8fafc 0%, #e2e8f0 100%);
}
h1, h2, h3, h4 { font-weight: var(--heading-weight); }
section, .section { padding-top: var(--space-section); padding-bottom: var(--space-section); }
.card, [class*="card"] {
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--space-card);
    transition: var(--transition);
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}
.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: var(--transition);
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    color: #fff;
    box-shadow: 0 4px 12px -2px rgba(59,130,246,.5);
}
a:not([class]) { color: var(--color-primary); transition: var(--transition); }

/* ========== Section Layout Variants ========== */

/* news: masonry-2 */
/* 两列瀑布流 */
.news-grid { column-count: 2; column-gap: var(--space-gap); }
.news-grid .card { break-inside: avoid; margin-bottom: var(--space-gap); }

/* features: horizontal */
/* 水平滚动 */
.feature-list {
    display: flex;
    gap: var(--space-gap);
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    scrollbar-color: rgba(100,116,139,.35) transparent;
}
.feature-list > * { flex: 0 0 300px; scroll-snap-align: start; }

/* hero: overlay */
/* 全屏背景+文字覆盖 */
.hero { position: relative; min-height: 70vh; display: flex; align-items: center; }
.hero-content {
    position: relative;
    z-index: 1;
    text-shadow: 0 2px 12px rgba(15,23,42,.35);
}

/* testimonials: grid-3 */
.testimonial-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); }

/* partners: centered */
.partner-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: 2rem; }

/* faq: with-sidebar */
/* FAQ 左 + 联系信息右 */
.faq-wrapper { display: grid; grid-template-columns: 2fr 1fr; gap: 2rem; }

/* stats: big-number */
/* 大数字居中 */
.stats-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: 2rem; }
.stats-grid .stat-value {
    font-size: 3rem;
    background: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: #1d4ed8;
}

/* cta: full-bg */
.cta-section {
    background: linear-gradient(135deg, #1e293b 0%, #1d4ed8 55%, #3b82f6 100%);
    color: #fff;
    padding: 3.5rem 1.75rem;
    text-shadow: 0 2px 8px rgba(15,23,42,.25);
}

/* Page Layout: narrow-centered */
/* 窄版居中 */
.page-main { max-width: 860px; margin: 0 auto; }

/* 条件性装饰 */
.card:hover, [class*="card"]:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
a:not([class]):hover {
    color: var(--color-accent);
    text-shadow: 0 0 12px rgba(56,189,248,.4);
}
.hero, [class*="hero"], section:first-of-type {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 45%, #1d4ed8 100%);
}
header, .header, .navbar {
    background: rgba(248,250,252,.82);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    backdrop-filter: blur(16px) saturate(180%);
    box-shadow: 0 1px 2px rgba(15,23,42,.06), 0 8px 24px -12px rgba(15,23,42,.14);
}

/* Responsive */
@media (max-width: 1024px) {
    .news-grid { grid-template-columns: repeat(2, 1fr) !important; }
    .feature-list { grid-template-columns: repeat(2, 1fr) !important; }
    .partner-grid { grid-template-columns: repeat(3, 1fr) !important; }
    .stats-grid { grid-template-columns: repeat(2, 1fr) !important; }
    .hero-inner { grid-template-columns: 1fr !important; }
}
@media (max-width: 640px) {
    :root {
        --space-section: 1.75rem;
        --space-card: 0.875rem;
        --space-gap: 0.625rem;
    }
    .news-grid { grid-template-columns: 1fr !important; }
    .feature-list { grid-template-columns: 1fr !important; }
    .faq-list { grid-template-columns: 1fr !important; }
    .testimonial-list { column-count: 1 !important; }
    .partner-grid { grid-template-columns: repeat(2, 1fr) !important; }
    .stats-grid { grid-template-columns: repeat(2, 1fr) !important; }
    .cta-inner { grid-template-columns: 1fr !important; }
}