:root {
    --color-primary: #334155;
    --color-primary-dark: #0b1220;
    --color-accent: #3b82f6;
    --color-surface: #f3f6fb;
    --color-text: #0f172a;
    --rgb-primary: 51,65,85;
    --rgb-accent: 59,130,246;
    --radius-sm: 10px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --shadow-sm: 0 6px 14px rgba(2, 6, 23, .08), 0 1px 0 rgba(255,255,255,.55) inset;
    --shadow-md: 0 10px 28px rgba(2, 6, 23, .10), 0 2px 0 rgba(255,255,255,.55) inset;
    --shadow-lg: 0 18px 50px rgba(2, 6, 23, .18), 0 6px 18px rgba(59,130,246,.14), 0 1px 0 rgba(255,255,255,.6) inset;
    --space-section: 2rem;
    --space-card: 1rem;
    --space-gap: 0.75rem;
    --transition: 0.38s cubic-bezier(0.16, 1, 0.3, 1);
    --heading-weight: 800;
    --body-line-height: 1.75;
}

body { color: var(--color-text); line-height: var(--body-line-height); background: linear-gradient(180deg, rgba(30,41,59,.96), rgba(15,23,42,.98)); }
h1, h2, h3, h4 { font-weight: var(--heading-weight); text-shadow: 0 1px 0 rgba(255,255,255,.06); }
section, .section { padding-top: var(--space-section); padding-bottom: var(--space-section); }
.card, [class*="card"] {
    border-radius: var(--radius-lg);
    box-shadow:
        0 4px 10px rgba(2, 6, 23, .10),
        0 18px 40px rgba(2, 6, 23, .10),
        0 1px 0 rgba(255,255,255,.45) inset;
    padding: var(--space-card);
    transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition), background var(--transition);
}
.btn, button[class*="btn"], a[class*="btn"] { border-radius: var(--radius-md); transition: transform var(--transition), box-shadow var(--transition), background var(--transition), border-color var(--transition), color var(--transition); }
a:not([class]) { color: var(--color-accent); transition: color var(--transition), text-shadow var(--transition), opacity var(--transition); text-shadow: 0 0 0 rgba(0,0,0,0); }

/* ========== 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-2 */
.feature-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: calc(var(--space-gap) * 1.5); }

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

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

/* partners: scroll */
/* 自动滚动 */
                .partner-grid { display: flex; gap: 2rem; overflow: hidden; animation: partnerScroll 18s linear infinite; filter: saturate(1.05); }
                @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: 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 10px 26px rgba(2, 6, 23, .18); }

/* cta: card-style */
.cta-inner {
    background:
        radial-gradient(1200px 360px at 20% 0%, rgba(59,130,246,.22), rgba(59,130,246,0) 55%),
        linear-gradient(180deg, #f8fbff, #eef4ff);
    border-radius: var(--radius-xl);
    padding: 3rem;
    text-align: center;
    box-shadow:
        0 16px 44px rgba(2, 6, 23, .16),
        0 2px 0 rgba(255,255,255,.65) inset;
    border: 1px solid rgba(59,130,246,.22);
}

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

/* 条件性装饰 */
.card:hover, [class*="card"]:hover {
    transform: translateY(-5px);
    box-shadow:
        0 8px 22px rgba(2, 6, 23, .14),
        0 26px 70px rgba(2, 6, 23, .16),
        0 8px 28px rgba(59,130,246,.16),
        0 1px 0 rgba(255,255,255,.7) inset;
    border-color: rgba(var(--rgb-accent), .35);
}
a:not([class]):hover { color: #2563eb; text-shadow: 0 0 18px rgba(37,99,235,.28); }
.hero, [class*="hero"], section:first-of-type {
    background:
        radial-gradient(1100px 420px at 18% -10%, rgba(59,130,246,.28), rgba(59,130,246,0) 58%),
        linear-gradient(135deg, #1e293b, #0f172a);
    border-radius: 18px;
    box-shadow:
        0 30px 90px rgba(2, 6, 23, .20),
        0 1px 0 rgba(255,255,255,.05) inset;
}
.card { border: 1px solid rgba(var(--rgb-primary), .16); }
header, .header, .navbar {
    box-shadow:
        0 10px 26px rgba(2,0,0,.12),
        0 2px 0 rgba(255,255,255,.06) inset;
    background: rgba(15,23,42,.78);
    border: 1px solid rgba(148,163,184,.16);
    backdrop-filter: blur(10px);
}

/* 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; }
}