:root {
    --color-primary: #0ea5e9;
    --color-primary-dark: #075985;
    --color-accent: #a78bfa;
    --color-surface: #eff6ff;
    --color-text: #0b1220;
    --rgb-primary: 14,165,233;
    --rgb-accent: 167,139,250;
    --radius-sm: 3px;
    --radius-md: 4px;
    --radius-lg: 2px;
    --radius-xl: 0px;
    --shadow-sm: 1px 1px 0px rgba(2, 6, 23, .28);
    --shadow-md: 4px 4px 0px rgba(2, 6, 23, .22), 0 10px 20px rgba(2, 6, 23, .12);
    --shadow-lg: 4px 4px 0px rgba(2, 6, 23, .28), 0 16px 30px rgba(2, 6, 23, .18);
    --space-section: 3rem;
    --space-card: 1.25rem;
    --space-gap: 1rem;
    --transition: 0.15s cubic-bezier(.2,.85,.25,1);
    --heading-weight: 650;
    --body-line-height: 1.6;
    --border-strong: rgba(2, 6, 23, .22);
    --outline-strong: rgba(14, 165, 233, .55);
    --focus-ring: rgba(167, 139, 250, .55);
    --card-bg: rgba(239, 246, 255, .98);
}

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);
    box-shadow:
        4px 4px 0px rgba(2, 6, 23, .22),
        -2px -2px 0px rgba(14, 165, 233, .18),
        0 10px 22px rgba(2, 6, 23, .10);
    padding: var(--space-card);
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background-color var(--transition);
    border: 3px solid rgba(2, 6, 23, .18);
    background: linear-gradient(180deg, rgba(255,255,255,.92) 0%, rgba(239, 246, 255, .96) 100%);
}
.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: background-color var(--transition), color var(--transition), border-color var(--transition), box-shadow var(--transition), transform var(--transition);
    outline-offset: 3px;
    caret-color: var(--color-primary);
    accent-color: var(--color-primary);
}
a:not([class]) { color: var(--color-primary); transition: var(--transition); }
a:not([class]):focus-visible { outline: 2px solid var(--outline-strong); outline-style: solid; }

.card:hover, [class*="card"]:hover {
    transform: translateY(-4px);
    box-shadow:
        4px 4px 0px rgba(2, 6, 23, .28),
        -2px -2px 0px rgba(167, 139, 250, .18),
        0 18px 34px rgba(2, 6, 23, .18);
    border-color: rgba(2, 6, 23, .28);
}

.hero, [class*="hero"], section:first-of-type {
    background:
        radial-gradient(900px 260px at 20% 0%, rgba(14,165,233,.55), rgba(14,165,233,0) 60%),
        radial-gradient(800px 280px at 85% 10%, rgba(167,139,250,.52), rgba(167,139,250,0) 58%),
        linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 55%, #1f2937 100%);
    filter: saturate(1.05) contrast(1.03);
}

.hero, [class*="hero"] {
    border-bottom: 3px solid rgba(2, 6, 23, .18);
}

@keyframes partnerScroll { 0% { transform: translateX(0); } 100% { transform: translateX(-50%); } }

/* 基础覆盖 */
.card:focus-visible, [class*="card"]:focus-visible {
    outline: 2px solid var(--focus-ring);
    outline-style: solid;
    outline-offset: 3px;
}

.card:hover img, [class*="card"]:hover img { filter: contrast(1.05) saturate(1.05) brightness(1.02); }

.feature-list, .stats-grid { align-items: baseline; }

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

/* news: list-view */
/* 列表模式 (图左文右) */
                .news-grid { display: flex; flex-direction: column; gap: var(--space-gap); }
                .news-grid .card { display: grid; grid-template-columns: 280px 1fr; }

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

/* 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: scroll */
/* 自动滚动 */
                .partner-grid { display: flex; gap: 2rem; overflow: hidden; animation: partnerScroll 18s linear infinite; }
                @media (prefers-reduced-motion: reduce) { .partner-grid { animation: none !important; } }

/* faq: two-column */
.faq-list { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-gap); }

/* stats: grid-4 */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-gap); text-align: center; }

/* 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; }
}