:root {
    --color-primary: #3b82f6;
    --color-primary-dark: #1e40af;
    --color-accent: #38bdf8;
    --color-surface: #ffffff;
    --color-text: #1e293b;
    --rgb-primary: 59,130,246;
    --rgb-accent: 56,189,248;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 18px;
    --shadow-sm: 0 1px 2px rgba(15,23,42,.08), 0 4px 12px -6px rgba(30,64,175,.18);
    --shadow-md: 0 2px 4px rgba(15,23,42,.06), 0 12px 28px -12px rgba(30,64,175,.22), 0 24px 48px -24px rgba(15,23,42,.18);
    --shadow-lg: 0 4px 8px -4px rgba(30,64,175,.16), 0 16px 32px -12px rgba(59,130,246,.4), 0 40px 80px -32px rgba(15,23,42,.28);
    --space-section: 2rem;
    --space-card: 1rem;
    --space-gap: 0.75rem;
    --transition: 0.55s cubic-bezier(0.22, 0.61, 0.36, 1);
    --heading-weight: 700;
    --body-line-height: 1.65;
}

body {
    color: var(--color-text);
    line-height: var(--body-line-height);
    background:
        radial-gradient(1000px 520px at 88% -12%, rgba(59,130,246,.16), transparent 62%),
        radial-gradient(720px 420px at 4% 108%, rgba(56,189,248,.12), transparent 58%),
        linear-gradient(180deg, #f8fafc 0%, #f1f5f9 58%, #e2e8f0 100%);
}

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);
    background:
        linear-gradient(135deg, rgba(59,130,246,.05) 0%, transparent 45%),
        linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: var(--transition);
    color: #ffffff;
    background: linear-gradient(135deg, #38bdf8 0%, #3b82f6 55%, #1d4ed8 100%);
    box-shadow: inset 0 1px 0 rgba(255,255,255,.2), 0 8px 18px -8px rgba(37,99,235,.65);
    text-shadow: 0 1px 2px rgba(15,23,42,.18);
}

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

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

/* news: masonry-2 */
/* 两列瀑布流 */
.news-grid { column-count: 2; column-gap: var(--space-gap); }
.news-grid .card { break-inside: avoid; margin-bottom: var(--space-gap); }

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

/* hero: minimal */
.hero { padding: 2rem 0; }
.hero-content { max-width: 560px; }

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

/* 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: single-column */
.faq-list { max-width: 800px; margin: 0 auto; }

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

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

/* 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); }

.hero, [class*="hero"], section:first-of-type {
    background:
        radial-gradient(720px 320px at 85% 0%, rgba(56,189,248,.25), transparent 60%),
        linear-gradient(135deg, #0f172a 0%, #1e293b 34%, #334155 68%, #3b82f6 100%);
    box-shadow: inset 0 1px 0 rgba(255,255,255,.08), 0 16px 48px -24px rgba(15,23,42,.6);
}

.card {
    border: 1px solid transparent;
    border-image: linear-gradient(135deg, rgba(59,130,246,.2) 0%, rgba(56,189,248,.45) 50%, rgba(30,64,175,.15) 100%) 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; }
}