:root {
    --color-primary: #1f6feb;
    --color-primary-dark: #1554b8;
    --color-accent: #38bdf8;
    --color-surface: #f4f7fb;
    --color-text: #1e2733;
    --rgb-primary: 31,111,235;
    --rgb-accent: 56,189,248;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --shadow-sm: 0 1px 3px rgba(31,111,235,0.08), 0 0 12px rgba(56,189,248,0.10);
    --shadow-md: 0 4px 14px rgba(37,46,58,0.10), 0 0 24px rgba(56,189,248,0.14);
    --shadow-lg: 0 8px 28px rgba(37,46,58,0.14), 0 0 32px rgba(56,189,248,0.20);
    --space-section: 4rem;
    --space-card: 1.5rem;
    --space-gap: 1.25rem;
    --transition: 0.35s cubic-bezier(0.22, 0.61, 0.36, 1);
    --heading-weight: 700;
    --body-line-height: 1.6;
}

/* 基础覆盖 */
body { color: var(--color-text); line-height: var(--body-line-height); background: var(--color-surface); }
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: #ffffff; }
.card:hover, [class*="card"]:hover { box-shadow: 0 0 32px rgba(56,189,248,0.6), 0 6px 20px rgba(37,46,58,0.14); }
.btn, button[class*="btn"], a[class*="btn"] { border-radius: var(--radius-md); transition: var(--transition); box-shadow: 0 0 18px rgba(56,189,248,0.30); }
.btn:hover, button[class*="btn"]:hover, a[class*="btn"]:hover { box-shadow: 0 0 32px rgba(56,189,248,0.6), 0 0 24px rgba(31,111,235,0.35); }
a:not([class]) { color: var(--color-primary); transition: var(--transition); }

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

/* news: featured-top */
/* 首篇横跨全宽 */
                .news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); }
                .news-grid > *:first-child { grid-column: span 3; }

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

/* hero: centered */
.hero-content { text-align: center; max-width: 800px; margin: 0 auto; }

/* 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: var(--color-primary); text-shadow: 0 0 24px rgba(56,189,248,0.45); }

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

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

/* 条件性装饰 */
header, .header, .navbar { box-shadow: 0 2px 12px rgba(37,46,58,0.10), 0 0 20px rgba(56,189,248,0.12); background: #252e3a; }

/* 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; }
}