:root {
    --color-primary: #3b82f6;
    --color-primary-dark: #1e40af;
    --color-accent: #60a5fa;
    --color-surface: #ffffff;
    --color-text: #e2e8f0;
    --rgb-primary: 59,130,246;
    --rgb-accent: 96,165,250;
    --radius-sm: 2px;
    --radius-md: 4px;
    --radius-lg: 6px;
    --radius-xl: 8px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 2px 4px rgba(0,0,0,0.08);
    --shadow-lg: 0 4px 8px rgba(0,0,0,0.1);
    --space-section: 3.5rem;
    --space-card: 1.25rem;
    --space-gap: 1rem;
    --transition: 0.2s ease-in-out;
    --heading-weight: 700;
    --body-line-height: 1.65;
}

body { background: #0f172a; color: var(--color-text); line-height: var(--body-line-height); }
h1, h2, h3, h4 { font-weight: var(--heading-weight); color: #f1f5f9; }
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: var(--color-surface); color: #1e293b; }
.btn, button[class*="btn"], a[class*="btn"] { border-radius: var(--radius-md); transition: var(--transition); }
a:not([class]) { color: var(--color-primary); transition: var(--transition); }

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

/* news: grid-4 */
/* 四列紧凑网格 */
.news-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: calc(var(--space-gap) * 0.8); }

/* 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: minimal */
.hero { padding: 2rem 0; } .hero-content { max-width: 560px; }

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

/* partners: scroll */
/* 自动滚动 */
.partner-grid { display: flex; gap: 2rem; overflow: hidden; animation: partnerScroll 20s linear infinite; }
@keyframes partnerScroll { 0% { transform: translateX(0); } 100% { transform: translateX(-50%); } }

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

/* 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; color: #3b82f6; }

/* cta: card-style */
.cta-inner { background: var(--color-surface); border-radius: var(--radius-xl); padding: 3rem; text-align: center; }

/* Page Layout: full-width */
/* 无侧边栏, 全宽 */
.page-main { max-width: 1200px; margin: 0 auto; }

/* 条件性装饰 */
.card:hover, [class*="card"]:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.hero, [class*="hero"], section:first-of-type { background: linear-gradient(135deg, #1e293b, #3b82f6); }
.card { border-left: 3px solid var(--color-primary); }
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; }
}