:root {
    --color-primary: #3b82f6;
    --color-primary-dark: #1d4ed8;
    --color-accent: #22c55e;
    --color-surface: #f8fafc;
    --color-text: #0b1220;
    --rgb-primary: 59,130,246;
    --rgb-accent: 34,197,94;
    --radius-sm: 4px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 18px;
    --shadow-sm: none;
    --shadow-md: none;
    --shadow-lg: none;
    --space-section: 5rem;
    --space-card: 2rem;
    --space-gap: 1.5rem;
    --transition: 220ms cubic-bezier(.2,.9,.2,1);
    --heading-weight: 800;
    --body-line-height: 1.6;
}

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);
    background:
        radial-gradient(1200px 420px at 10% -10%, rgba(59,130,246,.10), transparent 55%),
        radial-gradient(900px 360px at 95% 0%, rgba(34,197,94,.10), transparent 58%),
        linear-gradient(180deg, rgba(255,255,255,.78), rgba(255,255,255,.62));
    border: 1px solid rgba(15,23,42,.10);
    box-shadow:
        0 10px 26px rgba(2,6,23,.10),
        0 2px 10px rgba(2,6,23,.06),
        0 0 0 1px rgba(59,130,246,.06) inset;
    padding: var(--space-card);
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background var(--transition), filter var(--transition);
}

.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: background var(--transition), color var(--transition), box-shadow var(--transition), transform var(--transition), border-color var(--transition), filter var(--transition);
}

a:not([class]) {
    color: var(--color-primary);
    transition: color var(--transition), text-shadow var(--transition), filter var(--transition);
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
}

a:not([class]):hover {
    color: var(--color-accent);
    text-shadow: 0 0 18px rgba(34,197,94,.35);
    filter: saturate(1.15);
}

header, .header, .navbar {
    box-shadow:
        0 18px 50px rgba(2,6,23,.08),
        0 2px 10px rgba(2,6,23,.05),
        0 0 0 1px rgba(59,130,246,.10) inset;
}

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

/* testimonials: masonry */
.testimonial-list { column-count: 2; column-gap: var(--space-gap); }
                .testimonial-list > * { break-inside: avoid; margin-bottom: 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: 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: card-style */
.cta-inner {
    background:
        radial-gradient(1100px 360px at 0% 0%, rgba(59,130,246,.18), transparent 55%),
        radial-gradient(950px 340px at 100% 20%, rgba(34,197,94,.16), transparent 58%),
        linear-gradient(180deg, rgba(248,250,252,.92), rgba(248,250,252,.70));
    border-radius: var(--radius-xl);
    padding: 3rem;
    text-align: center;
    border: 1px solid rgba(15,23,42,.10);
    box-shadow:
        0 24px 70px rgba(2,6,23,.12),
        0 10px 26px rgba(2,6,23,.07),
        0 0 0 1px rgba(34,197,94,.12) inset,
        0 0 26px rgba(34,197,94,.18);
}

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

/* 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; }
}