:root {
    --color-primary: #6366f1;
    --color-primary-dark: #4338ca;
    --color-accent: #f43f5e;
    --color-surface: #f8fafc;
    --color-text: #1e293b;
    --rgb-primary: 99,102,241;
    --rgb-accent: 244,63,94;
    --radius-sm: 4px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.02);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
    --space-section: 4rem;
    --space-card: 1.5rem;
    --space-gap: 1.25rem;
    --transition: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    --heading-weight: 700;
    --body-line-height: 1.75;
}

body {
    background: linear-gradient(135deg, #f8fafc, #e2e8f0);
    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);
    background: radial-gradient(circle at 20% 50%, #eef2ff, transparent 70%);
}

.card, [class*="card"] {
    background: #ffffff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--space-card);
    transition: var(--transition);
    border: 1px solid transparent;
    border-image: linear-gradient(135deg, var(--color-primary), var(--color-accent)) 1;
}

.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: 24px;
    transition: var(--transition);
    background: linear-gradient(to right, var(--color-primary), var(--color-accent));
    color: #ffffff;
    border: none;
}

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

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

/* news: grid-3 */
/* 三列等宽网格 */
.news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); }

/* features: horizontal */
/* 水平滚动 */
.feature-list { display: flex; gap: var(--space-gap); overflow-x: auto; scroll-snap-type: x mandatory; }
.feature-list > * { flex: 0 0 300px; scroll-snap-align: start; }

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

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

/* partners: grid-4 */
.partner-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: calc(var(--space-gap) * 1.5); align-items: center; }

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

/* stats: inline */
/* 水平排列 */
.stats-grid { display: flex; justify-content: center; gap: 3rem; }

/* cta: centered */
.cta-inner { text-align: center; max-width: 700px; margin: 0 auto; }

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

/* 条件性装饰 */
a:not([class]):hover { color: var(--color-accent); }

.card {
    background: #ffffff;
    border: 1px solid transparent;
    border-image: linear-gradient(135deg, var(--color-primary), var(--color-accent)) 1;
}

/* 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; }
}