*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --c-brand: #2563eb;
    --c-text: #1e293b;
    --c-muted: #64748b;
    --c-border: #e2e8f0;
    --c-bg: #ffffff;
    --c-surface: #f8fafc;
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

html { font-size: 16px; -webkit-font-smoothing: antialiased; }

body {
    font-family: var(--font);
    color: var(--c-text);
    background: var(--c-bg);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container { max-width: 960px; margin: 0 auto; padding: 0 1.5rem; }

/* Header */
.site-header {
    border-bottom: 1px solid var(--c-border);
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(8px);
    position: sticky;
    top: 0;
    z-index: 100;
}
.nav-container { display: flex; align-items: center; justify-content: space-between; height: 56px; }
.logo { display: flex; align-items: center; gap: 0.5rem; text-decoration: none; }
.logo-img { display: block; height: 28px; width: auto; }
.logo-text { font-size: 1rem; font-weight: 700; color: var(--c-text); letter-spacing: 0.03em; }
.main-nav { display: flex; gap: 0.25rem; }
.nav-link { text-decoration: none; color: var(--c-muted); padding: 0.35rem 0.75rem; border-radius: 6px; font-size: 0.9rem; transition: all 0.2s; }
.nav-link:hover, .nav-link.active { color: var(--c-text); background: var(--c-surface); }
.mobile-toggle { display: none; background: none; border: none; font-size: 1.4rem; cursor: pointer; color: var(--c-text); }

/* Main */
main { flex: 1; }

/* Hero (home) */
.hero { display: flex; align-items: center; justify-content: center; min-height: calc(100vh - 56px - 48px); padding: 2rem 1rem; }
.hero-inner { max-width: 540px; margin: 0 auto; text-align: center; }
.hero-tagline { font-size: 1.05rem; color: var(--c-brand); font-weight: 600; margin-bottom: 1rem; letter-spacing: 0.04em; }
.hero-desc { font-size: 0.95rem; color: var(--c-muted); margin-bottom: 2rem; line-height: 1.8; }
.hero-desc p { margin-bottom: 0.75rem; }
.hero-buttons { display: flex; gap: 0.6rem; justify-content: center; flex-wrap: wrap; margin-bottom: 2rem; }
.hero-contact { display: flex; gap: 1.25rem; justify-content: center; flex-wrap: wrap; font-size: 0.85rem; color: var(--c-muted); }

.btn {
    display: inline-block;
    padding: 0.55rem 1.5rem;
    border-radius: 6px;
    font-size: 0.88rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s;
    letter-spacing: 0.02em;
    background: var(--c-brand);
    color: #fff;
    border: 1.5px solid var(--c-brand);
}
.btn:hover { background: #1d4ed8; border-color: #1d4ed8; transform: translateY(-1px); box-shadow: 0 4px 12px rgba(37,99,235,0.3); }
.btn-outline { background: transparent; color: var(--c-text); border-color: var(--c-border); }
.btn-outline:hover { background: var(--c-surface); border-color: #94a3b8; color: var(--c-text); transform: translateY(-1px); box-shadow: 0 2px 8px rgba(0,0,0,0.06); }

/* Footer */
.site-footer { border-top: 1px solid var(--c-border); padding: 0.75rem 0; text-align: center; font-size: 0.78rem; color: var(--c-muted); background: var(--c-surface); }
.site-footer a { color: var(--c-muted); text-decoration: none; }
.site-footer a:hover { color: var(--c-text); }

/* Page */
.page-header { background: var(--c-surface); border-bottom: 1px solid var(--c-border); padding: 2.5rem 0; text-align: center; }
.page-header h1 { font-size: 1.6rem; font-weight: 700; }
.page-header .blog-date { color: var(--c-muted); font-size: 0.85rem; margin-top: 0.5rem; }
.page-content { padding: 3rem 1.5rem; max-width: 760px; margin: 0 auto; }
.page-content h2 { font-size: 1.25rem; margin: 2rem 0 0.75rem; }
.page-content h3 { font-size: 1.05rem; margin: 1.5rem 0 0.5rem; }
.page-content p { margin-bottom: 0.75rem; color: var(--c-muted); line-height: 1.85; }
.page-content ul, .page-content ol { margin: 0.75rem 0; padding-left: 1.5rem; }
.page-content li { margin-bottom: 0.35rem; color: var(--c-muted); }
.page-content blockquote { margin: 1.5rem 0; padding: 1rem 1.25rem; background: var(--c-surface); border-left: 3px solid var(--c-brand); border-radius: 0 6px 6px 0; color: var(--c-muted); }
.page-content img { max-width: 100%; border-radius: 6px; margin: 1rem 0; }

/* Blog list */
.blog-list { display: flex; flex-direction: column; gap: 1rem; margin-top: 2rem; }
.blog-card {
    display: block;
    padding: 1.25rem 1.5rem;
    border: 1px solid var(--c-border);
    border-radius: 8px;
    text-decoration: none;
    transition: all 0.2s;
    background: var(--c-bg);
}
.blog-card:hover { border-color: var(--c-brand); box-shadow: 0 4px 12px rgba(37,99,235,0.12); transform: translateY(-2px); }
.blog-card h3 { font-size: 1.1rem; color: var(--c-text); margin-bottom: 0.35rem; }
.blog-date { font-size: 0.82rem; color: var(--c-muted); margin-bottom: 0.4rem; }
.blog-intro { font-size: 0.9rem; color: var(--c-muted); }
.blog-empty { color: var(--c-muted); text-align: center; padding: 2rem 0; }
.blog-back { margin-top: 3rem; font-size: 0.9rem; }
.blog-back a { color: var(--c-brand); text-decoration: none; }

/* Contact */
.contact-items { display: grid; gap: 0.75rem; margin-top: 1rem; }
.contact-item { display: flex; align-items: flex-start; gap: 0.75rem; padding: 1rem; border: 1px solid var(--c-border); border-radius: 6px; }
.contact-item h3 { font-size: 0.95rem; margin: 0 0 0.1rem; color: var(--c-text); }
.contact-item p { font-size: 0.88rem; margin: 0; }

@media (max-width: 640px) {
    .logo-text { font-size: 0.85rem; }
    .main-nav { display: none; flex-direction: column; position: absolute; top: 56px; left: 0; right: 0; background: var(--c-bg); border-bottom: 1px solid var(--c-border); padding: 0.5rem; }
    .main-nav.open { display: flex; }
    .mobile-toggle { display: block; }
    .hero-contact { flex-direction: column; gap: 0.35rem; }
}