:root {
    --color-primary: #0ea5e9;
    --color-primary-dark: #0369a1;
    --color-accent: #f97316;
    --color-surface: #f0f9ff;
    --color-text: #0f172a;
    --rgb-primary: 14,165,233;
    --rgb-accent: 249,115,22;
    --radius-sm: 3px;
    --radius-md: 5px;
    --radius-lg: 6px;
    --radius-xl: 10px;
    --shadow-sm: 0 1px 0 rgba(var(--rgb-primary), .12), 0 6px 18px rgba(14,165,233,.10);
    --shadow-md: 0 1px 0 rgba(2,132,199,.18), 0 8px 26px rgba(2,132,199,.14), 0 2px 10px rgba(15,23,42,.06);
    --shadow-lg: 0 2px 0 rgba(2,132,199,.18), 0 16px 42px rgba(14,165,233,.16), 0 8px 22px rgba(15,23,42,.08);
    --space-section: 4rem;
    --space-card: 1.5rem;
    --space-gap: 1.25rem;
    --transition: 160ms cubic-bezier(0.2, 0.9, 0.2, 1);
    --heading-weight: 650;
    --body-line-height: 1.75;
    --border-soft: rgba(14,165,233,.18);
    --focus-ring: rgba(14,165,233,.35);
}

/* 基础覆盖 */
body {
    color: var(--color-text);
    line-height: var(--body-line-height);
    background: radial-gradient(900px 420px at 15% -10%, rgba(var(--rgb-primary), .10), transparent 55%),
                radial-gradient(700px 360px at 85% 0%, rgba(var(--rgb-accent), .10), transparent 55%),
                linear-gradient(180deg, #f8fbff 0%, var(--color-surface) 100%);
    caret-color: var(--color-primary);
    accent-color: var(--color-primary);
}
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:
        0 1px 0 rgba(15,23,42,.06),
        0 10px 26px rgba(14,165,233,.10),
        0 2px 10px rgba(249,115,22,.06);
    padding: var(--space-card);
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background-color var(--transition), color var(--transition);
}
.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: background-color var(--transition), color var(--transition), box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}
a:not([class]) {
    color: var(--color-primary);
    text-shadow: 0 1px 0 rgba(255,255,255,.35);
    transition: color var(--transition), text-shadow 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: centered */
/* 居中大卡片 */
                .feature-list { display: flex; flex-direction: column; align-items: center; gap: calc(var(--space-gap) * 2); max-width: 720px; margin: 0 auto; }

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

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

/* partners: grid-6 */
.partner-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: var(--space-gap); align-items: center; }

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

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

/* 条件性装饰 */
.card { border: 1px solid rgba(var(--rgb-primary), .14); }
header, .header, .navbar {
    box-shadow:
        0 1px 0 rgba(15,23,42,.06),
        0 10px 28px rgba(14,165,233,.12),
        0 2px 14px rgba(249,115,22,.08);
    background: linear-gradient(180deg, rgba(255,255,255,.72) 0%, rgba(240,249,255,.62) 100%);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    border-bottom: 1px solid rgba(var(--rgb-primary), .14);
}

/* 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; }
}