/* 深色主题（body.dark 生效，默认浅色） */
body.dark { --bg: #0f1523; --bg-alt: #151d2f; --ink: #dde3ef; --muted: #8b96ad; --line: #242e45; background: #0f1523; color: #dde3ef; }
body.dark .site-header { background: rgba(15,21,35,0.94); border-bottom-color: #242e45; }
body.dark .brand { color: #dde3ef; }
body.dark .main-nav a { color: #dde3ef; }
body.dark .nav-toggle { color: #dde3ef; }
body.dark .main-nav.open { background: #0f1523; border-bottom-color: #242e45; }
body.dark .hero { background: linear-gradient(160deg, #0b101d 0%, #0f1523 60%); }
body.dark .hero-lead, body.dark .section-lead, body.dark .page-lead, body.dark .eyebrow, body.dark .hero-proof { color: #8b96ad; }
body.dark .section.alt { background: #121a2b; }
body.dark .product-card, body.dark .feature-item, body.dark .plan-card, body.dark .stat-card, body.dark .faq-item, body.dark .feedback-item { background: #151d2f; border-color: #242e45; }
body.dark .product-card-inner { color: #dde3ef; }
body.dark .product-card p, body.dark .feature-item p, body.dark .plan-desc, body.dark .plan-days { color: #8b96ad; }
body.dark .auth-card, body.dark .account-nav { background: #151d2f; border-color: #242e45; }
body.dark .account-user { background: #121a2b; border-bottom-color: #242e45; }
body.dark .account-nav a { color: #dde3ef; border-bottom-color: #121a2b; }
body.dark .account-nav a:hover, body.dark .account-nav a.active { background: #1c2740; }
body.dark .data-table { background: #151d2f; border-color: #242e45; }
body.dark .data-table th { background: #121a2b; color: #8b96ad; }
body.dark .data-table td { border-bottom-color: #242e45; }
body.dark .form-group input, body.dark .form-group select, body.dark .form-group textarea { background: #0f1523; border-color: #2a3550; color: #dde3ef; }
body.dark .form-group input:disabled { background: #121a2b; }
body.dark .button.ghost { background: #151d2f; border-color: #2a3550; color: #7ea2ff; }
body.dark .button.ghost:hover { background: #1c2740; }
body.dark .vip-banner { background: #151d2f; border-color: #242e45; }
body.dark .vip-banner.vip-active { background: linear-gradient(120deg, #131c33, #151d2f); border-color: #2a3550; }
body.dark .breadcrumbs a, body.dark .breadcrumbs, body.dark .article-meta, body.dark .footnote, body.dark .empty-tip, body.dark .filter-bar a { color: #8b96ad; }
body.dark .filter-bar a.active { background: #2b6bff; color: #fff; }
body.dark .faq-item p, body.dark .faq-item summary::after { color: #8b96ad; }
body.dark .feedback-reply { background: #121a2b; }
body.dark .danger-zone { background: #1a1418; border-color: #4a2a2a; }
body.dark .alert-ok { background: #0f2318; color: #57c07e; border-color: #1d402c; }
body.dark .alert-error { background: #261315; color: #ef8f8f; border-color: #4a2626; }
body.dark .article-body { color: #dde3ef; }
body.dark .admin-main h1 small, body.dark .admin-bar .logout-btn { color: #c8d0de; }
body.dark .theme-btn { background: #151d2f; border-color: #2a3550; color: #ffd76a; }
.theme-btn { margin-left: 4px; background: #fff; border: 1px solid var(--line); border-radius: 999px; padding: 5px 12px; cursor: pointer; font-size: 0.9rem; }
.footer-wechat { color: #c8d0de; font-size: 0.88rem; padding: 4px 0; }