:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-accent: #f97316;
    --color-surface: #f4f6fb;
    --color-text: #0f172a;
    --rgb-primary: 37,99,235;
    --rgb-accent: 249,115,22;

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 14px;
    --radius-xl: 16px;

    --shadow-sm:
        0 1px 0 rgba(15, 23, 42, .04),
        0 8px 18px rgba(2, 6, 23, .06);
    --shadow-md:
        0 1px 0 rgba(2, 6, 23, .03),
        0 10px 26px rgba(2, 6, 23, .08),
        0 0 0 1px rgba(37, 99, 235, .06);
    --shadow-lg:
        0 1px 0 rgba(2, 6, 23, .03),
        0 18px 52px rgba(2, 6, 23, .12),
        0 0 0 1px rgba(37, 99, 235, .08);

    --space-section: 4rem;
    --space-card: 1.5rem;
    --space-gap: 1.25rem;

    --transition: 170ms cubic-bezier(.2,.9,.2,1);
    --heading-weight: 700;
    --body-line-height: 1.6;

    --shadow-glow: 0 0 24px rgba(var(--rgb-accent), .40);
    --shadow-halo: 0 0 32px rgba(var(--rgb-accent), .60);
    --card-highlight: rgba(249, 115, 22, .18);
    --card-border: rgba(15, 23, 42, .08);
}

/* 基础覆盖 */
body {
    color: var(--color-text);
    line-height: var(--body-line-height);
    background:
        radial-gradient(1000px 600px at 15% -10%, rgba(37, 99, 235, .10), transparent 60%),
        radial-gradient(900px 520px at 85% 0%, rgba(249, 115, 22, .10), transparent 58%),
        linear-gradient(to bottom, #ffffff 0%, var(--color-surface) 55%, #f7f9ff 100%);
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    caret-color: var(--color-accent);
    accent-color: var(--color-accent);
}

h1, h2, h3, h4 { font-weight: var(--heading-weight); letter-spacing: -0.01em; }

section, .section { padding-top: var(--space-section); padding-bottom: var(--space-section); }

.card, [class*="card"] {
    border-radius: var(--radius-lg);
    padding: var(--space-card);
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background var(--transition), filter var(--transition), opacity var(--transition);
    background:
        linear-gradient(180deg, rgba(255,255,255,.95) 0%, rgba(255,255,255,.86) 100%);
    border: 1px solid rgba(15, 23, 42, .06);
    box-shadow:
        0 1px 0 rgba(2, 6, 23, .03),
        0 12px 28px rgba(2, 6, 23, .10),
        0 0 0 1px rgba(37, 99, 235, .06);
    position: relative;
    overflow: hidden;
}

.card::before, [class*="card"]::before{
    content: "";
    position: absolute;
    inset: -2px;
    background:
        radial-gradient(600px 180px at 20% 0%, rgba(249, 115, 22, .18), transparent 55%),
        radial-gradient(520px 170px at 90% 20%, rgba(37, 99, 235, .14), transparent 52%);
    opacity: .65;
    pointer-events: none;
    transition: opacity var(--transition), transform var(--transition);
    transform: translateY(6px);
}

.card:hover, [class*="card"]:hover{
    box-shadow:
        0 1px 0 rgba(2, 6, 23, .03),
        0 18px 52px rgba(2, 6, 23, .14),
        var(--shadow-halo),
        0 0 0 1px rgba(249, 115, 22, .16);
    border-color: rgba(249, 115, 22, .22);
}

.card:hover::before, [class*="card"]:hover::before{
    opacity: .95;
    transform: translateY(0);
}

.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: transform var(--transition), box-shadow var(--transition), background var(--transition), border-color var(--transition), color var(--transition), filter var(--transition), opacity var(--transition);
    text-shadow: 0 1px 0 rgba(2, 6, 23, .18);
    will-change: transform, box-shadow;
}

a:not([class]) {
    color: var(--color-primary);
    transition: var(--transition);
    text-shadow: 0 0 0 rgba(0,0,0,0);
}

a:not([class]):hover{
    color: var(--color-primary-dark);
    text-shadow: 0 0 16px rgba(37, 99, 235, .22);
}

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

/* news: featured-left */
/* 左大右小 (1大+2小) */
                .news-grid { display: grid; grid-template-columns: 2fr 1fr; grid-template-rows: auto auto; gap: var(--space-gap); }
                .news-grid > *:first-child { grid-row: span 2; }

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

/* partners: centered */
.partner-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: 2rem; }

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

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

/* cta: full-bg */
.cta-section {
    background:
        radial-gradient(900px 480px at 15% 0%, rgba(255,255,255,.22), transparent 58%),
        radial-gradient(760px 420px at 90% 20%, rgba(var(--rgb-accent), .28), transparent 56%),
        linear-gradient(120deg, var(--color-primary) 0%, #3b82f6 40%, var(--color-primary-dark) 100%);
    color: #ffffff;
    padding: 4rem 2rem;
    box-shadow:
        0 18px 60px rgba(37, 99, 235, .22),
        0 0 0 1px rgba(255,255,255,.10) inset;
}

.cta-section *{
    text-shadow: 0 1px 0 rgba(2, 6, 23, .25);
}

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

/* 条件性装饰 */
header, .header, .navbar { background: transparent; }

/* 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; }
}