:root {
    --color-primary: #0ea5e9;
    --color-primary-dark: #0369a1;
    --color-accent: #22c55e;
    --color-surface: #f8fafc;
    --color-text: #0f172a;
    --rgb-primary: 14,165,233;
    --rgb-accent: 34,197,94;

    --radius-sm: 0px;
    --radius-md: 3px;
    --radius-lg: 2px;
    --radius-xl: 3px;

    --shadow-sm: 4px 4px 0 rgba(2, 132, 199, .35), 0 1px 0 rgba(15, 23, 42, .06), 0 10px 22px rgba(2, 132, 199, .12);
    --shadow-md: 4px 4px 0 rgba(15, 23, 42, .12), 0 0 0 2px rgba(255,255,255,.7) inset, 0 10px 26px rgba(2, 132, 199, .10);
    --shadow-lg: 6px 6px 0 rgba(15, 23, 42, .14), 0 0 0 2px rgba(255,255,255,.72) inset, 0 18px 40px rgba(2, 132, 199, .14);

    --space-section: 4rem;
    --space-card: 1.5rem;
    --space-gap: 1.25rem;

    --transition: 0.15s cubic-bezier(0.2, 0.9, 0.2, 1);

    --heading-weight: 800;
    --body-line-height: 1.6;
}

/* 基础覆盖 */
body { color: var(--color-text); line-height: var(--body-line-height); background: linear-gradient(180deg, #f1f5f9 0%, #f8fafc 100%); }
h1, h2, h3, h4 { font-weight: var(--heading-weight); letter-spacing: -0.01em; }
section, .section { padding-top: var(--space-section); padding-bottom: var(--space-section); }
.card, [class*="card"] {
    border-radius: var(--radius-xl);
    box-shadow:
        4px 4px 0 rgba(2, 132, 199, .35),
        -2px 0 0 rgba(34, 197, 94, .18),
        0 0 0 2px rgba(2, 132, 199, .14) inset,
        0 18px 40px rgba(2, 132, 199, .10);
    background:
        linear-gradient(180deg, rgba(255,255,255,.98) 0%, rgba(255,255,255,.92) 100%);
    padding: var(--space-card);
    transition:
        transform var(--transition),
        box-shadow var(--transition),
        border-color var(--transition),
        background var(--transition),
        color var(--transition),
        filter var(--transition);
}
.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition:
        background-color var(--transition),
        border-color var(--transition),
        color var(--transition),
        transform var(--transition),
        box-shadow var(--transition),
        filter var(--transition);
    border: 2px solid rgba(3, 105, 161, .28);
}
a:not([class]) { color: var(--color-primary); transition: var(--transition); text-decoration-thickness: 2px; text-underline-offset: 3px; }
a:not([class]):hover { filter: saturate(1.05); }

header, .header, .navbar {
    box-shadow:
        4px 4px 0 rgba(2, 132, 199, .28),
        0 0 0 2px rgba(255,255,255,.75) inset,
        0 16px 34px rgba(2, 132, 199, .10);
}

/* ========== 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: centered */
/* 居中大卡片 */
                .feature-list { display: flex; flex-direction: column; align-items: center; gap: calc(var(--space-gap) * 2); max-width: 720px; margin: 0 auto; }

/* hero: split */
/* 左文右图 */
                .hero-inner { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; align-items: center; }

/* testimonials: stacked */
/* 垂直堆叠 */
                .testimonial-list { display: flex; flex-direction: column; gap: var(--space-gap); max-width: 720px; margin: 0 auto; }

/* partners: centered */
.partner-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: 2rem; }

/* 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; text-shadow: 4px 4px 0 rgba(2, 132, 199, .22); color: #0b2440; }

/* cta: split */
.cta-inner { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 2rem; }

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