:root {
    --bg: #ffffff; --surface: #f4f6f4; --text: #05140a; --text-secondary: #4c5a51;
    --yellow: #FFCB00; --yellow-hover: #e6b000; --green: #009C3B; --green-hover: #007c2f;
    --green-soft: rgba(0,156,59,0.10); --border: #e2e6e2; --ink: #05140a;
    --radius: 24px; --radius-sm: 14px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg); color: var(--text); line-height: 1.5;
    -webkit-font-smoothing: antialiased; letter-spacing: -0.01em;
}
.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* Nav (shared) */
.navbar {
    display: flex; align-items: center; justify-content: space-between;
    padding: 16px 32px; position: sticky; top: 0; z-index: 100;
    background: rgba(255,255,255,0.92); backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
}
.nav-logo { font-weight: 900; font-size: 1.35rem; text-decoration: none; color: var(--ink); display: flex; align-items: center; gap: 9px; letter-spacing: -0.04em; }
.nav-logo img { width: 30px; height: 30px; border-radius: 8px; }
.nav-logo .pix { color: var(--green); } .nav-logo .btc { color: var(--yellow); }
.nav-links { display: flex; align-items: center; gap: 14px; }
.nav-link { text-decoration: none; color: var(--ink); font-weight: 600; font-size: 0.95rem; padding: 9px 8px; transition: opacity .15s; }
.nav-link:hover { opacity: .6; }
.lang-toggle { border: 2px solid var(--ink); border-radius: 100px; padding: 7px 14px; font-weight: 800; font-size: 0.82rem; text-decoration: none; color: var(--ink); transition: all .15s; }
.lang-toggle:hover { background: var(--ink); color: #fff; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 9px; padding: 14px 26px; border-radius: 100px; font-weight: 700; font-size: 0.95rem; text-decoration: none; transition: all .15s; border: 2px solid var(--ink); }
.btn-sm { padding: 10px 18px; font-size: 0.85rem; }
.btn-green { background: var(--green); color: #fff; }
.btn-green:hover { background: var(--green-hover); transform: translate(-2px,-2px); box-shadow: 4px 4px 0 var(--ink); }

/* Doc header */
.doc-head { padding: 60px 0 24px; text-align: center; border-bottom: 2px solid var(--ink); }
.doc-head .badge {
    display: inline-flex; align-items: center; gap: 8px; background: var(--green-soft);
    border: 1px solid rgba(0,156,59,0.25); padding: 6px 15px; border-radius: 100px;
    font-size: 0.82rem; font-weight: 700; color: var(--green-hover); margin-bottom: 18px;
}
.doc-head h1 { font-size: clamp(2rem,4vw,3rem); font-weight: 900; letter-spacing: -0.04em; line-height: 1.08; max-width: 800px; margin: 0 auto; }
.doc-head .sub { color: var(--text-secondary); margin-top: 16px; font-size: 1rem; }

/* Living-doc layout: sticky TOC + prose */
.layout { display: grid; grid-template-columns: 240px 1fr; gap: 48px; padding: 40px 0 90px; align-items: start; }
.toc { position: sticky; top: 88px; max-height: calc(100vh - 110px); overflow-y: auto; padding-right: 8px; }
.toc-title { font-size: 0.72rem; font-weight: 800; text-transform: uppercase; letter-spacing: 0.08em; color: var(--green); margin-bottom: 12px; }
.toc a { display: block; text-decoration: none; color: var(--text-secondary); font-size: 0.85rem; font-weight: 600; padding: 5px 0 5px 12px; border-left: 2px solid var(--border); transition: all .15s; }
.toc a:hover { color: var(--ink); border-left-color: var(--green); }

/* Prose (rendered markdown) */
.prose { max-width: 760px; }
.prose h1 { display: none; } /* title already in doc-head */
.prose h2 { font-size: clamp(1.5rem,3vw,2rem); font-weight: 900; letter-spacing: -0.03em; margin: 48px 0 16px; padding-top: 12px; border-top: 2px solid var(--border); }
.prose h2:first-of-type { border-top: none; padding-top: 0; margin-top: 8px; }
.prose h3 { font-size: 1.25rem; font-weight: 800; margin: 32px 0 12px; letter-spacing: -0.02em; }
.prose h4 { font-size: 1.05rem; font-weight: 800; margin: 24px 0 10px; }
.prose p { color: var(--text-secondary); margin: 0 0 16px; line-height: 1.7; }
.prose strong { color: var(--text); font-weight: 700; }
.prose ul, .prose ol { margin: 0 0 18px; padding-left: 22px; color: var(--text-secondary); line-height: 1.7; }
.prose li { margin-bottom: 8px; }
.prose a { color: var(--green-hover); font-weight: 600; text-decoration: underline; text-underline-offset: 2px; }
.prose hr { border: none; border-top: 2px dashed var(--border); margin: 40px 0; }
.prose blockquote {
    border: 2px solid var(--ink); border-left: 6px solid var(--yellow); border-radius: var(--radius-sm);
    background: var(--surface); padding: 16px 22px; margin: 0 0 20px; color: var(--text);
    box-shadow: 5px 5px 0 var(--yellow);
}
.prose blockquote p { color: var(--text); margin-bottom: 8px; }
.prose blockquote p:last-child { margin-bottom: 0; }
.prose code {
    font-family: 'JetBrains Mono', monospace; font-size: 0.85em;
    background: var(--surface); border: 1px solid var(--border); border-radius: 6px; padding: 1px 6px;
}
.prose pre {
    background: var(--ink); color: #e8f0e8; border-radius: var(--radius-sm); padding: 20px;
    overflow-x: auto; margin: 0 0 20px; border: 2px solid var(--ink);
}
.prose pre code { background: none; border: none; color: inherit; padding: 0; }
.prose .table-wrap { overflow-x: auto; margin: 0 0 24px; border: 2px solid var(--ink); border-radius: var(--radius-sm); box-shadow: 6px 6px 0 var(--ink); }
.prose table { width: 100%; border-collapse: collapse; min-width: 480px; }
.prose th, .prose td { padding: 12px 16px; text-align: left; font-size: 0.9rem; vertical-align: top; border-bottom: 2px solid var(--border); }
.prose thead th { background: var(--green); color: #fff; font-weight: 800; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.04em; }
.prose tbody tr:nth-child(even) { background: var(--surface); }
.prose td:first-child { font-weight: 600; color: var(--text); }
.prose .mermaid {
    background: var(--surface); border: 2px solid var(--ink); border-radius: var(--radius);
    padding: 24px; margin: 0 0 24px; text-align: center; overflow-x: auto;
}

/* Footer */
.footer { border-top: 2px solid var(--ink); padding: 44px 0 32px; }
.footer-grid { display: flex; align-items: center; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.footer-logo { font-weight: 900; font-size: 1.2rem; letter-spacing: -0.04em; }
.footer-logo .pix { color: var(--green); } .footer-logo .btc { color: var(--yellow-hover); }
.footer-links { display: flex; gap: 24px; }
.footer-links a { text-decoration: none; color: var(--text-secondary); font-weight: 600; font-size: 0.92rem; }
.footer-links a:hover { color: var(--ink); }

@media (max-width: 900px) {
    .layout { grid-template-columns: 1fr; }
    .toc { position: static; max-height: none; margin-bottom: 20px; border: 2px solid var(--ink); border-radius: var(--radius-sm); padding: 16px 18px; }
}
@media (max-width: 640px) { .navbar { padding: 14px 18px; } }