:root {
    --color-primary: #334155;
    --color-primary-dark: #1e293b;
    --color-accent: #3b82f6;
    --color-surface: #ffffff;
    --color-text: #0f172a;

    --rgb-primary: 51,65,85;
    --rgb-accent: 59,130,246;

    --radius-sm: 4px;
    --radius-md: 5px;
    --radius-lg: 6px;
    --radius-xl: 8px;

    --shadow-sm: none;
    --shadow-md: none;
    --shadow-lg: none;

    --space-section: 1.5rem;
    --space-card: 0.875rem;
    --space-gap: 0.75rem;

    --transition: 160ms cubic-bezier(0.2, 0.8, 0.2, 1);
    --heading-weight: 750;
    --body-line-height: 1.6;
}

body { color: var(--color-text); line-height: var(--body-line-height); background: #0b1220; }

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: none;
    padding: var(--space-card);

    background: #ffffff;
    color: #0f172a;

    border: 1px solid rgba(30, 41, 59, 0.14);
    transition: border-color var(--transition), background-color var(--transition), transform 140ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.btn, button[class*="btn"], a[class*="btn"] {
    border-radius: var(--radius-md);
    transition: background-color var(--transition), border-color var(--transition), color var(--transition), transform 140ms cubic-bezier(0.2, 0.8, 0.2, 1);
    border: 1px solid rgba(51, 65, 85, 0.22);
}

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

::selection { background: rgba(59, 130, 246, 0.28); color: #0b1220; }
input, textarea, select { caret-color: var(--color-accent); }

.card:hover, [class*="card"]:hover {
    transform: translateY(-2px);
    box-shadow: none;
    border-color: rgba(59, 130, 246, 0.55);
}

a:not([class]):hover { color: var(--color-accent); opacity: 1; }

header, .header, .navbar {
    box-shadow: none;
    background: rgba(30, 41, 59, 0.96);
    border-bottom: 1px solid rgba(148, 163, 184, 0.18);
    color: #ffffff;
}

/* ========== 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: grid-3 */
.feature-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); }

/* hero: overlay */
/* 全屏背景+文字覆盖 */
                .hero { position: relative; min-height: 70vh; display: flex; align-items: center; }
                .hero-content { position: relative; z-index: 1; }

/* testimonials: grid-3 */
.testimonial-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); }

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

/* cta: full-bg */
.cta-section { background: var(--color-primary-dark); color: #ffffff; padding: 4rem 2rem; border-top: 1px solid rgba(59, 130, 246, 0.22); border-bottom: 1px solid rgba(59, 130, 246, 0.22); }

/* Page Layout: full-width */
/* 无侧边栏, 全宽 */
            .page-main { max-width: 1200px; margin: 0 auto; }

/* 条件性装饰 */
.card:hover .title, [class*="card"]:hover .title { text-shadow: 0 0 0 rgba(0,0,0,0); }
.title, .card .title { text-shadow: none; }

a:not([class]):focus,
.btn:focus,
button[class*="btn"]:focus,
a[class*="btn"]:focus {
    outline: 2px solid rgba(59, 130, 246, 0.55);
    outline-offset: 2px;
    outline-style: solid;
}

/* 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: 1.5rem; --space-card: 0.875rem; --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; }
}