:root {
    --bg: #fafbfc;
    --surface: #ffffff;
    --text: #1a202c;
    --text-soft: #4a5568;
    --muted: #718096;
    --border: #e2e8f0;
    --accent: #6366f1;
    --accent-2: #8b5cf6;
    --accent-soft: #eef2ff;
    --code-bg: #1e1e2e;
    --shadow: 0 1px 3px rgba(0,0,0,.06), 0 8px 24px rgba(0,0,0,.05);
    --shadow-lg: 0 4px 12px rgba(99,102,241,.15), 0 20px 48px rgba(99,102,241,.12);
    --radius: 16px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0f1117;
        --surface: #171923;
        --text: #f7fafc;
        --text-soft: #cbd5e0;
        --muted: #a0aec0;
        --border: #2d3748;
        --accent: #818cf8;
        --accent-2: #a78bfa;
        --accent-soft: #1e1b4b;
        --code-bg: #0d0d16;
        --shadow: 0 1px 3px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.25);
        --shadow-lg: 0 4px 12px rgba(0,0,0,.4), 0 20px 48px rgba(0,0,0,.35);
    }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', -apple-system, system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    margin: 0;
    -webkit-font-smoothing: antialiased;
    font-feature-settings: "cv02","cv03","cv04","cv11";
}

/* ---- Top bar ---- */
.topbar {
    position: sticky;
    top: 0;
    z-index: 50;
    backdrop-filter: saturate(180%) blur(12px);
    background: color-mix(in srgb, var(--surface) 80%, transparent);
    border-bottom: 1px solid var(--border);
}
.topbar-inner {
    max-width: 1080px;
    margin: 0 auto;
    padding: .9rem 1.5rem;
    display: flex;
    align-items: center;
    gap: .6rem;
}
.brand {
    font-weight: 800;
    font-size: 1.05rem;
    color: var(--text);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: .55rem;
    letter-spacing: -.01em;
}
.brand .logo {
    width: 30px; height: 30px;
    display: grid; place-items: center;
    border-radius: 9px;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    color: #fff; font-size: .95rem;
    box-shadow: var(--shadow-lg);
}
.nav-links { margin-left: auto; display: flex; gap: 1.4rem; }
.nav-links a {
    color: var(--text-soft);
    text-decoration: none;
    font-weight: 500;
    font-size: .92rem;
    transition: color .15s;
}
.nav-links a:hover { color: var(--accent); }

/* ---- Layout ---- */
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 1.5rem; }
main { padding: 3rem 0 5rem; }

/* ---- Hero ---- */
.hero {
    text-align: center;
    padding: 4.5rem 1.5rem 3.5rem;
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: "";
    position: absolute; inset: 0;
    background:
        radial-gradient(60% 60% at 50% 0%, color-mix(in srgb, var(--accent) 18%, transparent), transparent 70%);
    pointer-events: none;
}
.hero .eyebrow {
    display: inline-block;
    font-size: .78rem;
    font-weight: 600;
    letter-spacing: .08em;
    text-transform: uppercase;
    color: var(--accent);
    background: var(--accent-soft);
    padding: .35rem .8rem;
    border-radius: 999px;
    margin-bottom: 1.2rem;
}
.hero h1 {
    font-size: clamp(2.2rem, 5vw, 3.4rem);
    line-height: 1.1;
    letter-spacing: -.03em;
    margin: 0 0 1rem;
    background: linear-gradient(135deg, var(--text), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.hero p { font-size: 1.15rem; color: var(--text-soft); max-width: 640px; margin: 0 auto; }

/* ---- Cards ---- */
.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.2rem;
    margin: 2.5rem 0;
}
.card {
    display: block;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.6rem;
    text-decoration: none;
    color: var(--text);
    box-shadow: var(--shadow);
    transition: transform .18s ease, box-shadow .18s ease, border-color .18s;
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent);
}
.card .icon {
    width: 44px; height: 44px;
    display: grid; place-items: center;
    border-radius: 12px;
    background: var(--accent-soft);
    color: var(--accent);
    font-size: 1.3rem;
    margin-bottom: 1rem;
}
.card h3 { margin: 0 0 .4rem; font-size: 1.15rem; letter-spacing: -.01em; }
.card p { margin: 0; color: var(--muted); font-size: .92rem; }
.card .arrow { color: var(--accent); font-weight: 700; margin-top: .8rem; display: inline-block; }

/* ---- Article ---- */
.article {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 3rem clamp(1.5rem, 5vw, 3.5rem);
    box-shadow: var(--shadow);
    max-width: 820px;
    margin: 0 auto;
}
.article h1 {
    font-size: 2.4rem;
    letter-spacing: -.025em;
    margin: 0 0 1.5rem;
    line-height: 1.15;
}
.article h2 {
    font-size: 1.6rem;
    letter-spacing: -.02em;
    margin: 2.5rem 0 1rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
}
.article h3 { font-size: 1.25rem; margin: 1.8rem 0 .8rem; }
.article p, .article li { color: var(--text-soft); }
.article a { color: var(--accent); text-decoration: none; border-bottom: 1px solid transparent; transition: border-color .15s; }
.article a:hover { border-bottom-color: var(--accent); }

/* ---- Code ---- */
code {
    font-family: 'JetBrains Mono', ui-monospace, monospace;
    font-size: .87em;
    background: var(--accent-soft);
    color: var(--accent);
    padding: .15em .4em;
    border-radius: 6px;
}
pre {
    background: var(--code-bg) !important;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.25rem 1.4rem !important;
    overflow-x: auto;
    box-shadow: inset 0 1px 0 rgba(255,255,255,.03);
    position: relative;
}
pre code {
    background: none;
    color: #e2e8f0;
    padding: 0;
    font-size: .88rem;
    line-height: 1.6;
}

/* ---- Tables ---- */
table {
    border-collapse: collapse;
    width: 100%;
    margin: 1.5rem 0;
    font-size: .92rem;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
}
th, td { padding: .8rem 1rem; text-align: left; border-bottom: 1px solid var(--border); }
th { background: var(--accent-soft); color: var(--text); font-weight: 600; }
tr:last-child td { border-bottom: none; }
tbody tr:hover { background: color-mix(in srgb, var(--accent) 5%, transparent); }

/* ---- Blockquote ---- */
blockquote {
    border-left: 4px solid var(--accent);
    background: var(--accent-soft);
    margin: 1.5rem 0;
    padding: 1rem 1.4rem;
    border-radius: 0 10px 10px 0;
    color: var(--text-soft);
}
blockquote p { margin: 0; }

.back-link {
    display: inline-flex; align-items: center; gap: .4rem;
    margin-top: 2.5rem;
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
}

/* ---- Footer ---- */
footer {
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    text-align: center;
    color: var(--muted);
    font-size: .88rem;
}