:root {
    --color-primary: #3b82f6;
    --color-primary-dark: #2563eb;
    --color-accent: #60a5fa;
    --color-surface: #f1f5f9;
    --color-text: #0f172a;
    --rgb-primary: 59,130,246;
    --rgb-accent: 96,165,250;
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --shadow-sm: 0 1px 2px rgba(15,23,42,0.06);
    --shadow-md: 0 4px 6px -1px rgba(15,23,42,0.08), 0 2px 4px -2px rgba(15,23,42,0.05);
    --shadow-lg: 0 10px 15px -3px rgba(15,23,42,0.1), 0 4px 6px -4px rgba(15,23,42,0.06);
    --space-section: 2rem;
    --space-card: 1rem;
    --space-gap: 0.75rem;
    --transition: 0.45s cubic-bezier(0.4,0,0.2,1);
    --heading-weight: 800;
    --body-line-height: 1.65;
}

/* 基础覆盖 */
body { color: var(--color-text); line-height: var(--body-line-height); background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%); }
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"] { background: #ffffff; border: none; border-radius: var(--radius-lg); box-shadow: var(--shadow-md); padding: var(--space-card); transition: var(--transition); backdrop-filter: blur(2px); }
.card:hover, [class*="card"]:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-image: linear-gradient(135deg, #3b82f6, #60a5fa) 1; }
.btn, button[class*="btn"], a[class*="btn"] { background: linear-gradient(135deg, #3b82f6, #2563eb); color: #fff; border: none; border-radius: var(--radius-md); transition: var(--transition); box-shadow: 0 4px 6px -1px rgba(59,130,246,0.3); }
.btn:hover, button[class*="btn"]:hover, a[class*="btn"]:hover { background: linear-gradient(135deg, #2563eb, #1d4ed8); box-shadow: 0 6px 10px -2px rgba(59,130,246,0.4); transform: translateY(-1px); }
a:not([class]) { color: var(--color-primary); transition: var(--transition); text-shadow: 0 1px 2px rgba(59,130,246,0.1); }

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

/* news: featured-left */
/* 左大右小 (1大+2小) */
                .news-grid { display: grid; grid-template-columns: 2fr 1fr; grid-template-rows: auto auto; gap: var(--space-gap); }
                .news-grid > *:first-child { grid-row: span 2; }

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

/* hero: minimal */
.hero { padding: 2rem 0; background: linear-gradient(135deg, #e2e8f0 0%, #f8fafc 100%); } .hero-content { max-width: 560px; }

/* testimonials: grid-3 */
.testimonial-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); }
.testimonial-list .card { background: #ffffff; border-left: 4px solid #3b82f6; }

/* partners: grid-4 */
.partner-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: calc(var(--space-gap) * 1.5); align-items: center; }

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

/* stats: grid-4 */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-gap); text-align: center; }
.stats-grid .card { background: #ffffff; border-bottom: 3px solid #3b82f6; }

/* cta: full-bg */
.cta-section { background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%); color: #fff; padding: 4rem 2rem; }

/* 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(-4px); box-shadow: var(--shadow-lg); }
a:not([class]):hover { color: var(--color-accent); text-shadow: 0 2px 4px rgba(96,165,250,0.3); }
header, .header, .navbar { background: transparent; box-shadow: none; }

/* 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; }
}