:root {
    --color-primary: #252e3a;
    --color-primary-dark: #1a212e;
    --color-accent: #2563eb;
    --color-surface: #f1f5f9;
    --color-text: #1e293b;
    --rgb-primary: 37, 46, 58;
    --rgb-accent: 37, 99, 235;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 18px;
    --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06), 0 0 8px rgba(37, 99, 235, .08);
    --shadow-md: 0 4px 14px rgba(15, 23, 42, .08), 0 0 24px rgba(37, 99, 235, .4);
    --shadow-lg: 0 6px 18px rgba(15, 23, 42, .12), 0 0 32px rgba(37, 99, 235, .6);
    --space-section: 3.4rem;
    --space-card: 1.4rem;
    --space-gap: 1.05rem;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --heading-weight: 800;
    --body-line-height: 1.7;
}

/* 基础覆盖 */
body {
    color: var(--color-text);
    line-height: var(--body-line-height);
    background-color: var(--color-surface);
    caret-color: var(--color-accent);
    accent-color: var(--color-accent);
}
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: var(--shadow-md);
    padding: var(--space-card);
    transition: var(--transition);
    animation: glow-pulse 5s ease-in-out infinite;
}
.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    box-shadow: 0 0 24px rgba(37, 99, 235, .4);
    transition: var(--transition);
}
a:not([class]) {
    color: var(--color-accent);
    transition: var(--transition);
    text-shadow: 0 0 12px rgba(37, 99, 235, .2);
}

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

/* news: grid-4 */
.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: left-aligned */
.hero-content { text-align: left; max-width: 600px; }

/* testimonials: stacked */
.testimonial-list { display: flex; flex-direction: column; gap: var(--space-gap); max-width: 720px; margin: 0 auto; }

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

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

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

/* 条件性装饰 */
.hero, [class*="hero"], section:first-of-type {
    background: radial-gradient(circle at 20% 30%, rgba(37, 99, 235, .2), transparent 60%), linear-gradient(135deg, #1e293b, #0f172a);
}
.card { border-left: 3px solid var(--color-accent); }

@keyframes glow-pulse {
    0%, 100% { box-shadow: var(--shadow-md); }
    50% { box-shadow: var(--shadow-lg); }
}

/* 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: 2.25rem; --space-card: 1.1rem; --space-gap: 0.8rem; }
    .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; }
}