:root {
    --color-primary: #3b82f6;
    --color-primary-dark: #1d4ed8;
    --color-accent: #f59e0b;
    --color-surface: #ffffff;
    --color-text: #f1f5f9;
    --rgb-primary: 59,130,246;
    --rgb-accent: 245,158,11;
    --radius-sm: 0;
    --radius-md: 0;
    --radius-lg: 4px;
    --radius-xl: 4px;
    --shadow-sm: 2px 2px 0px #0f172a;
    --shadow-md: 4px 4px 0px #1e293b, 0 0 0 2px #cbd5e1;
    --shadow-lg: 6px 6px 0px #0f172a, 0 0 0 2px #94a3b8;
    --space-section: 4rem;
    --space-card: 1.6rem;
    --space-gap: 1.2rem;
    --transition: 0.15s ease-out;
    --heading-weight: 600;
    --body-line-height: 1.7;
}

body {
    color: var(--color-text);
    background: #1e293b;
    line-height: var(--body-line-height);
}

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

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

.card, [class*="card"] {
    background: var(--color-surface);
    color: #0f172a;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--space-card);
    transition: var(--transition);
}

.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: var(--transition);
}

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

/* ========== 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: stacked */
/* 垂直堆叠 */
.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 左 + 联系信息右 */
.faq-wrapper {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
}

/* 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: var(--color-primary);
    color: #fff;
    padding: 4rem 2rem;
}

/* Page Layout: wide */
/* 超宽 */
.page-main {
    max-width: 1400px;
    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: 3rem;
        --space-card: 1.4rem;
        --space-gap: 1rem;
    }

    .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; }
}