:root {
    --color-primary: #4a90e2;
    --color-primary-dark: #003d66;
    --color-accent: #f39c12;
    --color-surface: #ffffff;
    --color-text: #2c3e50;
    --rgb-primary: 74,144,226;
    --rgb-accent: 243,156,18;
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 32px;
    --shadow-sm: 0 2px 4px rgba(0,0,0,.2), 0 1px 3px rgba(0,0,0,.1);
    --shadow-md: 0 6px 12px rgba(0,0,0,.2), 0 3px 6px rgba(0,0,0,.1);
    --shadow-lg: 0 15px 20px rgba(0,0,0,.2), 0 6px 8px rgba(0,0,0,.1);
    --space-section: 4rem;
    --space-card: 1.5rem;
    --space-gap: 1.5rem;
    --transition: 0.4s ease-in-out;
    --heading-weight: 700;
    --body-line-height: 1.7;
}

/* 基础覆盖 */
body { color: var(--color-text); line-height: var(--body-line-height); }
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); }
.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-3 */
/* 三列等宽网格 */
                .news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); }

/* features: grid-4 */
.feature-list { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-gap); }

/* 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: carousel */
/* 单条轮播 */
                .testimonial-list { display: flex; overflow: hidden; } 
                .testimonial-list > * { flex: 0 0 100%; }

/* partners: grid-6 */
.partner-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: var(--space-gap); align-items: center; }

/* faq: single-column */
.faq-list { max-width: 800px; margin: 0 auto; }

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

/* cta: centered */
.cta-inner { text-align: center; max-width: 700px; margin: 0 auto; }

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

/* 条件性装饰 */
a:not([class]):hover { color: var(--color-accent); }
.hero, [class*="hero"], section:first-of-type { background: linear-gradient(135deg, #4a90e2, #003d66); }
.card { border-left: 4px 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: 2.5rem; --space-card: 1.25rem; --space-gap: 1rem; }
    .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; }
}