*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; color: #1e293b; background: #fff; line-height: 1.6; }
a { color: #0284c7; text-decoration: none; }
a:hover { text-decoration: underline; }

/* NAV */
.nav { background: #0ea5e9; padding: 0 2rem; display: flex; align-items: center; height: 56px; gap: 1.5rem; }
.nav-logo { color: #fff; font-weight: 700; font-size: 1.1rem; display: flex; align-items: center; gap: 0.5rem; text-decoration: none; }
.nav-logo svg { width: 22px; height: 22px; }
.nav-links { display: flex; gap: 1rem; margin-left: auto; }
.nav-links a { color: rgba(255,255,255,0.85); font-size: 0.875rem; text-decoration: none; }
.nav-links a:hover { color: #fff; }

/* HERO */
.hero { background: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 100%); padding: 3.5rem 2rem; text-align: center; position: relative; overflow: hidden; }
.hero h1 { font-size: 2rem; font-weight: 700; color: #0c4a6e; margin-bottom: 1.25rem; }
.hero-search { display: flex; max-width: 560px; margin: 0 auto; gap: 0; }
.hero-search input { flex: 1; padding: 0.75rem 1rem 0.75rem 2.75rem; border: 1px solid #bae6fd; border-radius: 8px 0 0 8px; font-size: 0.95rem; outline: none; background: #fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2'%3E%3Ccircle cx='11' cy='11' r='8'/%3E%3Cpath d='m21 21-4.35-4.35'/%3E%3C/svg%3E") no-repeat 0.75rem center; }
.hero-search button { padding: 0.75rem 1.5rem; background: #0284c7; color: #fff; border: none; border-radius: 0 8px 8px 0; font-weight: 600; cursor: pointer; }
.hero-search button:hover { background: #0369a1; }

/* PAGE HERO (inner pages) */
.page-hero { background: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 100%); padding: 2rem 2rem 1.5rem; }
.page-hero .breadcrumb { font-size: 0.8rem; color: #0369a1; margin-bottom: 0.5rem; }
.page-hero h1 { font-size: 1.6rem; font-weight: 700; color: #0c4a6e; }
.page-hero p { color: #0369a1; margin-top: 0.3rem; }

/* CARDS GRID */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 1.25rem; max-width: 1100px; margin: 2.5rem auto; padding: 0 2rem; }
.card { border: 1px solid #e2e8f0; border-radius: 12px; padding: 1.75rem 1.5rem; text-align: center; transition: box-shadow 0.2s, border-color 0.2s; cursor: pointer; background: #fff; }
.card:hover { box-shadow: 0 4px 20px rgba(14,165,233,0.15); border-color: #7dd3fc; text-decoration: none; }
.card-icon { width: 56px; height: 56px; border-radius: 50%; background: #f0f9ff; display: flex; align-items: center; justify-content: center; margin: 0 auto 1rem; }
.card-icon svg { width: 26px; height: 26px; stroke: #0284c7; }
.card h3 { font-size: 1rem; font-weight: 600; color: #0f172a; margin-bottom: 0.4rem; }
.card p { font-size: 0.85rem; color: #64748b; }

/* CONTENT */
.content-wrap { max-width: 860px; margin: 0 auto; padding: 2rem 2rem 4rem; display: grid; grid-template-columns: 220px 1fr; gap: 2.5rem; }
.sidebar { position: sticky; top: 1rem; height: fit-content; }
.sidebar h4 { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: #94a3b8; margin-bottom: 0.75rem; }
.sidebar ul { list-style: none; }
.sidebar li a { display: block; padding: 0.35rem 0.5rem; border-radius: 6px; font-size: 0.875rem; color: #475569; }
.sidebar li a:hover, .sidebar li a.active { background: #f0f9ff; color: #0284c7; text-decoration: none; }
.article h2 { font-size: 1.3rem; font-weight: 700; color: #0f172a; margin: 2rem 0 0.75rem; padding-top: 1.5rem; border-top: 1px solid #f1f5f9; }
.article h2:first-child { border-top: none; margin-top: 0; padding-top: 0; }
.article h3 { font-size: 1rem; font-weight: 600; color: #1e293b; margin: 1.25rem 0 0.5rem; }
.article p { color: #475569; margin-bottom: 0.75rem; font-size: 0.925rem; }
.article ul, .article ol { color: #475569; font-size: 0.925rem; padding-left: 1.5rem; margin-bottom: 0.75rem; }
.article li { margin-bottom: 0.3rem; }
.article .tip { background: #f0f9ff; border-left: 3px solid #0ea5e9; padding: 0.75rem 1rem; border-radius: 0 8px 8px 0; margin: 1rem 0; font-size: 0.9rem; color: #0369a1; }
.article .warn { background: #fefce8; border-left: 3px solid #eab308; padding: 0.75rem 1rem; border-radius: 0 8px 8px 0; margin: 1rem 0; font-size: 0.9rem; color: #854d0e; }
.article table { width: 100%; border-collapse: collapse; margin: 1rem 0; font-size: 0.9rem; }
.article table th { background: #f8fafc; padding: 0.6rem 1rem; text-align: left; font-weight: 600; border: 1px solid #e2e8f0; color: #374151; }
.article table td { padding: 0.6rem 1rem; border: 1px solid #e2e8f0; color: #475569; }
.article table tr:nth-child(even) td { background: #f8fafc; }

/* KEYBOARD SHORTCUTS */
.shortcut-table { width: 100%; border-collapse: collapse; margin: 0.75rem 0 1.5rem; }
.shortcut-table tr:hover td { background: #f8fafc; }
.shortcut-table td { padding: 0.5rem 0.75rem; border-bottom: 1px solid #f1f5f9; font-size: 0.9rem; color: #475569; }
.shortcut-table td:first-child { font-weight: 500; color: #1e293b; width: 55%; }
kbd { display: inline-block; background: #f1f5f9; border: 1px solid #cbd5e1; border-bottom: 2px solid #94a3b8; border-radius: 4px; padding: 1px 6px; font-family: monospace; font-size: 0.8rem; color: #374151; white-space: nowrap; }

/* FOOTER */
footer { background: #f8fafc; border-top: 1px solid #e2e8f0; padding: 2rem; text-align: center; font-size: 0.85rem; color: #94a3b8; }
footer a { color: #0284c7; }

@media (max-width: 720px) {
  .content-wrap { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .cards { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) { .cards { grid-template-columns: 1fr; } }