:root {
    --color-primary: #334155;
    --color-primary-dark: #1e293b;
    --color-accent: #3b82f6;
    --color-surface: #f8fafc;
    --color-text: #0f172a;
    --rgb-primary: 51,65,85;
    --rgb-accent: 59,130,246;
    --radius-sm: 12px;
    --radius-md: 16px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --shadow-sm: 0 2px 4px -1px rgba(15,23,42,0.06), 0 1px 2px -1px rgba(15,23,42,0.04);
    --shadow-md: 0 6px 12px -4px rgba(15,23,42,0.08), 0 2px 4px -2px rgba(15,23,42,0.05);
    --shadow-lg: 0 20px 40px -8px rgba(15,23,42,0.12), 0 8px 16px -6px rgba(15,23,42,0.07);
    --space-section: 4rem;
    --space-card: 1.5rem;
    --space-gap: 1.25rem;
    --transition: 0.3s cubic-bezier(0.4,0,0.2,1);
    --heading-weight: 600;
    --body-line-height: 1.7;
}

body { 
    color: var(--color-text); 
    line-height: var(--body-line-height); 
    background-color: #e2e8f0;
}
h1, h2, h3, h4 { font-weight: var(--heading-weight); color: #1e293b; }
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: #ffffff;
    border: 1px solid rgba(51,65,85,0.06);
}
.card:hover, [class*="card"]:hover { 
    transform: translateY(-4px); 
    box-shadow: var(--shadow-lg); 
    border-color: rgba(59,130,246,0.15);
}
.btn, button[class*="btn"], a[class*="btn"] { 
    border-radius: var(--radius-md); 
    transition: var(--transition); 
    background: var(--color-accent);
    color: #ffffff;
    box-shadow: 0 2px 4px -1px rgba(59,130,246,0.3);
}
.btn:hover, button[class*="btn"]:hover, a[class*="btn"]:hover {
    background: #2563eb;
    box-shadow: 0 4px 8px -2px rgba(59,130,246,0.4);
    transform: translateY(-1px);
}
a:not([class]) { 
    color: var(--color-primary); 
    transition: var(--transition); 
    text-decoration: underline;
    text-underline-offset: 2px;
}
a:not([class]):hover { color: #3b82f6; }

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

/* news: list-view */
/* 列表模式 (图左文右) */
                .news-grid { display: flex; flex-direction: column; gap: var(--space-gap); }
                .news-grid .card { display: grid; grid-template-columns: 280px 1fr; }

/* features: horizontal */
/* 水平滚动 */
                .feature-list { display: flex; gap: var(--space-gap); overflow-x: auto; scroll-snap-type: x mandatory; }
                .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; }

/* 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: two-column */
.faq-list { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-gap); }

/* stats: grid-4 */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-gap); text-align: center; }

/* cta: split */
.cta-inner { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 2rem; }

/* Page Layout: wide */
/* 超宽 */
            .page-main { max-width: 1400px; margin: 0 auto; }

/* 条件性装饰 */
.card { border: 1px solid rgba(51,65,85,0.08); }
header, .header, .navbar { background: transparent; }

/* 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: 2rem; --space-card: 1rem; --space-gap: 0.75rem; }
    .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; }
}