:root {
    --color-primary: #334155;
    --color-primary-dark: #1e293b;
    --color-accent: #3b82f6;
    --color-surface: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
    --color-text: #f1f5f9;
    --rgb-primary: 51,65,85;
    --rgb-accent: 59,130,246;
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 18px;
    --radius-xl: 28px;
    --shadow-sm: 0 2px 4px rgba(30, 41, 59, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(30, 41, 59, 0.25), 0 2px 6px rgba(0, 0, 0, 0.15), inset 0 1px 0 rgba(255,255,255,0.05);
    --shadow-lg: 0 8px 24px rgba(15, 23, 42, 0.4), 0 4px 12px rgba(0, 0, 0, 0.2), inset 0 1px 0 rgba(255,255,255,0.08);
    --space-section: 3.5rem;
    --space-card: 1.25rem;
    --space-gap: 1rem;
    --transition: 0.5s cubic-bezier(0.25, 0.1, 0.25, 1);
    --heading-weight: 600;
    --body-line-height: 1.7;
}

body { color: var(--color-text); line-height: var(--body-line-height); background: linear-gradient(180deg, #0f172a 0%, #1e293b 40%, #0f172a 100%); }
h1, h2, h3, h4 { font-weight: var(--heading-weight); }
section, .section { padding-top: var(--space-section); padding-bottom: var(--space-section); 
    background: linear-gradient(135deg, rgba(59,130,246,0.03) 0%, transparent 60%);
}
.card, [class*="card"] { border-radius: var(--radius-lg); box-shadow: var(--shadow-md); padding: var(--space-card); transition: var(--transition);
    background: linear-gradient(145deg, #1e293b, #334155);
    border: 1px solid rgba(59,130,246,0.15);
    position: relative;
    overflow: hidden;
}
.card::before, [class*="card"]::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(135deg, rgba(59,130,246,0.08) 0%, transparent 50%);
    pointer-events: none;
}
.btn, button[class*="btn"], a[class*="btn"] { border-radius: var(--radius-md); transition: var(--transition);
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    border: none;
    color: #fff;
    box-shadow: 0 2px 8px rgba(59,130,246,0.3);
}
a:not([class]) { color: var(--color-accent); transition: var(--transition); text-shadow: 0 1px 2px rgba(0,0,0,0.3); }

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

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

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

/* hero: split */
.hero-inner { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; align-items: center;
    background: radial-gradient(ellipse at center, rgba(59,130,246,0.05) 0%, transparent 70%);
    padding: 2rem;
    border-radius: var(--radius-xl);
}

/* testimonials: masonry */
.testimonial-list { column-count: 2; column-gap: var(--space-gap); }
.testimonial-list > * { break-inside: avoid; margin-bottom: var(--space-gap); 
    box-shadow: var(--shadow-sm);
}

/* partners: centered */
.partner-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: 2rem; }
.partner-grid > * { filter: brightness(0.8) sepia(0.2) hue-rotate(220deg); transition: var(--transition); }
.partner-grid > *:hover { filter: brightness(1) sepia(0) hue-rotate(0); transform: scale(1.05); }

/* faq: with-sidebar */
.faq-wrapper { display: grid; grid-template-columns: 2fr 1fr; gap: 2rem; }

/* stats: grid-3 */
.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); text-align: center; }
.stats-grid .stat-item { background: linear-gradient(135deg, #1e293b, #334155); border-radius: var(--radius-md); padding: 1.5rem; box-shadow: var(--shadow-sm); }

/* cta: split */
.cta-inner { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 2rem;
    background: linear-gradient(135deg, #1e293b, #334155);
    border-radius: var(--radius-xl);
    padding: 2rem 3rem;
    box-shadow: var(--shadow-md);
}

/* Page Layout: full-width */
.page-main { max-width: 1200px; margin: 0 auto; padding: 0 1rem; }

/* 条件性装饰 */
.card:hover, [class*="card"]:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
a:not([class]):hover { color: #60a5fa; text-shadow: 0 0 8px rgba(59,130,246,0.5); }
.card { border: 1px solid rgba(var(--rgb-accent), .15); border-image: linear-gradient(135deg, rgba(59,130,246,0.2), rgba(99,102,241,0.2)) 1; }
header, .header, .navbar { background: linear-gradient(180deg, rgba(15,23,42,0.9), rgba(15,23,42,0.6)); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); }

/* 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; }
    .page-main { padding: 0 0.75rem; }
}
@media (max-width: 640px) {
    :root { --space-section: 2rem; --space-card: 0.9rem; --space-gap: 0.6rem; }
    .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; }
}