:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-accent: #60a5fa;
    --color-surface: #f8fafc;
    --color-text: #0f172a;
    --rgb-primary: 37,99,235;
    --rgb-accent: 96,165,250;
    --radius-sm: 3px;
    --radius-md: 4px;
    --radius-lg: 5px;
    --radius-xl: 8px;
    --shadow-sm: 0 1px 0 rgba(15, 23, 42, .08), 0 10px 24px rgba(37, 99, 235, .10);
    --shadow-md: 0 1px 0 rgba(15, 23, 42, .10), 0 12px 30px rgba(2, 6, 23, .08), 0 0 0 1px rgba(37, 99, 235, .10) inset;
    --shadow-lg: 0 1px 0 rgba(15, 23, 42, .12), 0 18px 48px rgba(2, 6, 23, .10), 0 0 0 1px rgba(37, 99, 235, .14) inset;
    --space-section: 5rem;
    --space-card: 2rem;
    --space-gap: 1.5rem;
    --transition: 220ms cubic-bezier(0.2, 0.95, 0.2, 1);
    --heading-weight: 650;
    --body-line-height: 1.6;
}

/* 基础覆盖 */
body { color: var(--color-text); line-height: var(--body-line-height); background: #0b1220; }
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:
        0 1px 0 rgba(148, 163, 184, .18),
        0 10px 26px rgba(2, 6, 23, .14),
        0 0 0 1px rgba(59, 130, 246, .18) inset;
    padding: var(--space-card);
    transition: var(--transition);
    background: linear-gradient(180deg, rgba(248,250,252,.98) 0%, rgba(241,245,249,.98) 100%);
}
.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); }
a:not([class]):hover, a:not([class]):focus { color: var(--color-primary-dark); }
h1, h2, h3, h4 { text-shadow: 0 1px 0 rgba(148, 163, 184, .10); }

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

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

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

/* 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: grid-3 */
.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); text-align: center; }

/* cta: card-style */
.cta-inner {
    background:
        radial-gradient(1200px 280px at 50% 0%, rgba(59, 130, 246, .22) 0%, rgba(59, 130, 246, 0) 60%),
        linear-gradient(180deg, rgba(248,250,252,.98) 0%, rgba(241,245,249,.98) 100%);
    border-radius: var(--radius-xl);
    padding: 3rem;
    text-align: center;
    box-shadow:
        0 1px 0 rgba(148, 163, 184, .18),
        0 16px 44px rgba(2, 6, 23, .14),
        0 0 0 1px rgba(37, 99, 235, .18) inset;
}

/* Page Layout: narrow-centered */
/* 窄版居中 */
            .page-main { max-width: 860px; margin: 0 auto; }

/* 条件性装饰 */

/* 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; }
}