:root {
    --color-primary: #0ea5e9;
    --color-primary-dark: #0369a1;
    --color-accent: #22c55e;
    --color-surface: #f6f7fb;
    --color-text: #0f172a;
    --rgb-primary: 14,165,233;
    --rgb-accent: 34,197,94;
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;
    --radius-xl: 12px;
    --shadow-sm: 0 0 0 rgba(0,0,0,0);
    --shadow-md: 0 1px 0 rgba(15,23,42,.04), 0 10px 24px rgba(15,23,42,.06);
    --shadow-lg: 0 1px 0 rgba(15,23,42,.05), 0 16px 40px rgba(15,23,42,.08);
    --space-section: 2rem;
    --space-card: 0.75rem;
    --space-gap: 0.625rem;
    --transition: 160ms cubic-bezier(.2,.8,.2,1);
    --heading-weight: 800;
    --body-line-height: 1.75;
    --card-border: rgba(2,132,199,.12);
    --card-accent: rgba(34,197,94,.22);
    --card-glow: rgba(14,165,233,.18);
    --focus-ring: rgba(14,165,233,.35);
}

/* 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-xl);
    box-shadow:
        0 1px 0 rgba(15,23,42,.06),
        0 10px 22px rgba(15,23,42,.06),
        0 0 0 1px rgba(2,132,199,.04) inset;
    padding: var(--space-card);
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background-color var(--transition);
    background:
        linear-gradient(180deg, rgba(255,255,255,.92) 0%, rgba(255,255,255,.78) 100%);
}
.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background-color var(--transition), color var(--transition);
}
a:not([class]) {
    color: var(--color-primary);
    transition: color var(--transition), text-shadow var(--transition), opacity var(--transition);
    text-shadow: 0 1px 0 rgba(255,255,255,.6);
}

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

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

/* 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; text-shadow: 0 1px 0 rgba(255,255,255,.7), 0 10px 24px rgba(14,165,233,.10); }

/* 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 */
.card { border: 1px solid rgba(var(--rgb-primary), .14); }
header, .header, .navbar {
    box-shadow:
        0 1px 0 rgba(15,23,42,.05),
        0 10px 26px rgba(15,23,42,.08);
    background: linear-gradient(180deg, rgba(255,255,255,.88) 0%, rgba(255,255,255,.74) 100%);
    border-bottom: 1px solid rgba(var(--rgb-primary), .10);
}

/* 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: 0.75rem; --space-gap: 0.625rem; }
    .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; }
}