:root {
    --color-primary: #4b5563;
    --color-primary-dark: #0b1220;
    --color-accent: #22c55e;
    --color-surface: #f6f8ff;
    --color-text: #0c1220;
    --rgb-primary: 75,85,99;
    --rgb-accent: 34,197,94;
    --radius-sm: 10px;
    --radius-md: 18px;
    --radius-lg: 26px;
    --radius-xl: 36px;
    --shadow-sm: 0 1px 0 rgba(255,255,255,.55), 0 10px 25px rgba(17,24,39,.10);
    --shadow-md: 0 1px 0 rgba(255,255,255,.65), 0 10px 35px rgba(7,13,26,.12), 0 2px 10px rgba(7,13,26,.08);
    --shadow-lg: 0 2px 0 rgba(255,255,255,.75), 0 18px 60px rgba(2,6,23,.18), 0 10px 25px rgba(2,6,23,.10), 0 0 0 1px rgba(255,255,255,.06) inset;
    --space-section: 3rem;
    --space-card: 1.25rem;
    --space-gap: 1rem;
    --transition: 0.52s cubic-bezier(0.2, 0.9, 0.2, 1);
    --heading-weight: 650;
    --body-line-height: 1.6;
}

/* 基础覆盖 */
body {
    color: var(--color-text);
    line-height: var(--body-line-height);
    background: radial-gradient(1200px 800px at 15% 0%, rgba(59,130,246,.10) 0%, rgba(59,130,246,0) 55%),
                radial-gradient(900px 700px at 90% 10%, rgba(34,197,94,.10) 0%, rgba(34,197,94,0) 50%),
                linear-gradient(180deg, #f8fafc 0%, #f3f6ff 60%, #eef2ff 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:
        0 1px 0 rgba(255,255,255,.75),
        0 18px 55px rgba(2,6,23,.12),
        0 8px 25px rgba(2,6,23,.08),
        0 0 0 1px rgba(15,23,42,.08) inset;
    padding: var(--space-card);
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background var(--transition), filter var(--transition);
    background:
        linear-gradient(180deg, rgba(255,255,255,.92) 0%, rgba(248,250,252,.75) 100%);
}
.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: transform var(--transition), box-shadow var(--transition), color var(--transition), background var(--transition), border-color var(--transition), filter var(--transition);
    box-shadow:
        0 1px 0 rgba(255,255,255,.7),
        0 14px 35px rgba(2,6,23,.12);
    background:
        linear-gradient(135deg, rgba(59,130,246,.16) 0%, rgba(34,197,94,.14) 60%, rgba(99,102,241,.12) 100%);
    border: 1px solid rgba(15,23,42,.10);
}
a:not([class]) {
    color: var(--color-primary);
    transition: var(--transition);
    text-shadow: 0 1px 0 rgba(255,255,255,.55);
}

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

/* news: grid-4 */
/* 四列紧凑网格 */
                .news-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: calc(var(--space-gap) * 0.8); }

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

/* hero: centered */
.hero-content { text-align: center; max-width: 800px; margin: 0 auto; }

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

/* 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-4 */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-gap); text-align: center; }

/* cta: card-style */
.cta-inner {
    background:
        radial-gradient(900px 240px at 10% 0%, rgba(59,130,246,.28) 0%, rgba(59,130,246,0) 55%),
        radial-gradient(700px 260px at 90% 10%, rgba(34,197,94,.22) 0%, rgba(34,197,94,0) 55%),
        linear-gradient(135deg, rgba(255,255,255,.92) 0%, rgba(248,250,252,.72) 45%, rgba(238,242,255,.85) 100%);
    border-radius: var(--radius-xl);
    padding: 3rem;
    text-align: center;
    box-shadow:
        0 1px 0 rgba(255,255,255,.8),
        0 22px 70px rgba(2,6,23,.16),
        0 10px 28px rgba(2,6,23,.10),
        0 0 0 1px rgba(99,102,241,.15) inset;
    border: 1px solid rgba(15,23,42,.08);
}

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

/* 条件性装饰 */
.card:hover, [class*="card"]:hover {
    transform: translateY(-6px);
    box-shadow:
        0 1px 0 rgba(255,255,255,.85),
        0 25px 85px rgba(2,6,23,.20),
        0 14px 35px rgba(2,6,23,.12),
        0 0 0 1px rgba(34,197,94,.18) inset;
    filter: saturate(1.06) contrast(1.02);
    background:
        linear-gradient(180deg, rgba(255,255,255,.96) 0%, rgba(248,250,252,.78) 100%);
}
a:not([class]):hover { color: var(--color-accent); }
.card { border-left: 3px solid transparent; border-left-color: transparent; border-image: linear-gradient(180deg, rgba(34,197,94,.95) 0%, rgba(59,130,246,.95) 55%, rgba(99,102,241,.95) 100%) 1; }
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; }
}