:root {
    --color-primary: #3b82f6;
    --color-primary-dark: #2563eb;
    --color-accent: #60a5fa;
    --color-surface: #ffffff;
    --color-text: #cbd5e1;
    --color-text-dark: #1e293b;
    --rgb-primary: 59,130,246;
    --rgb-accent: 96,165,250;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --shadow-sm: 0 4px 8px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.05), 0 20px 40px -10px rgba(0,0,0,0.12);
    --shadow-lg: 0 8px 16px rgba(0,0,0,0.08), 0 30px 50px -12px rgba(0,0,0,0.18);
    --space-section: 3.5rem;
    --space-card: 1.25rem;
    --space-gap: 1rem;
    --transition: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --heading-weight: 700;
    --body-line-height: 1.7;
}

body {
    background: #0f172a;
    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"] {
    background: var(--color-surface);
    color: var(--color-text-dark);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--space-card);
    transition: var(--transition);
}

.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: var(--transition);
}

a:not([class]) { color: var(--color-primary); transition: var(--transition); }

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

/* news: featured-top */
.news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); }
.news-grid > *:first-child { grid-column: span 3; }

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

/* hero: centered */
.hero-content { text-align: center; max-width: 800px; margin: 0 auto; }

/* testimonials: carousel */
.testimonial-list { display: flex; overflow: hidden; } 
.testimonial-list > * { flex: 0 0 100%; }

/* partners: scroll */
.partner-grid { display: flex; gap: 2rem; overflow: hidden; animation: partnerScroll 20s linear infinite; }
@keyframes partnerScroll { 0% { transform: translateX(0); } 100% { transform: translateX(-50%); } }

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

/* stats: big-number */
.stats-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: 2rem; }
.stats-grid .stat-value { font-size: 3rem; }

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

/* Page Layout: wide */
.page-main { max-width: 1400px; margin: 0 auto; }

/* 条件性装饰 */
.card:hover, [class*="card"]:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

a:not([class]):hover { color: var(--color-accent); }

header, .header, .navbar {
    background: #1e293b;
    box-shadow: 0 4px 8px rgba(0,0,0,0.15), 0 20px 30px -10px rgba(0,0,0,0.2);
}

/* 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; }
}