:root{
  --primary:#7c3aed;
  --secondary:#5b21b6;
  --accent:#65a30d;
  --bg:#ffffff;
  --surface:#faf5ff;
  --surface-alt:#f3e8ff;
  --text:#2e1065;
  --muted:#6b7280;
  --border:#ddd6fe;
  --row-alt:#faf5ff;
  --radius:12px;
  --shadow:0 6px 20px rgba(124,58,237,.10);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font:16px/1.7 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen,Ubuntu,Cantarell,"Helvetica Neue",Arial,sans-serif;
  color:var(--text);
  background:var(--bg);
}
img{max-width:100%;height:auto;display:block}
a{color:var(--secondary);text-decoration:underline;text-underline-offset:2px}
a:hover{color:var(--primary)}

header.site{
  position:sticky;top:0;z-index:50;
  background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);
  color:#fff;
  box-shadow:0 2px 12px rgba(46,16,101,.25);
}
header.site .wrap{
  max-width:1080px;margin:0 auto;padding:14px 20px;
  display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap;
}
.brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:#fff}
.brand img{width:40px;height:40px;background:#fff;border-radius:8px;padding:4px}
.brand span{font-weight:700;font-size:1.15rem;letter-spacing:.3px}
nav.primary ul{list-style:none;display:flex;flex-wrap:wrap;gap:6px;margin:0;padding:0}
nav.primary a{
  display:inline-block;padding:8px 12px;border-radius:8px;
  color:#fff;text-decoration:none;font-weight:500;font-size:.95rem;
  transition:background .15s ease;
}
nav.primary a:hover{background:rgba(255,255,255,.18)}

main{max-width:1080px;margin:0 auto;padding:24px 20px 60px}

.hero{
  background:linear-gradient(135deg,var(--surface-alt) 0%,#ede9fe 60%,#e0e7ff 100%);
  border:1px solid var(--border);
  border-radius:var(--radius);
  padding:32px 28px;
  margin:12px 0 28px;
  box-shadow:var(--shadow);
  position:relative;overflow:hidden;
}
.hero::before{
  content:"";position:absolute;top:-40px;right:-40px;width:180px;height:180px;
  background:radial-gradient(circle,rgba(101,163,13,.18),transparent 70%);border-radius:50%;
}
h1{
  font-size:clamp(1.75rem,2.4vw + 1rem,2.5rem);
  line-height:1.2;margin:0 0 12px;color:var(--secondary);
}
.byline{
  color:var(--muted);font-size:.92rem;margin:0 0 10px;
}
.byline strong{color:var(--text)}
.intro{font-size:1.08rem;margin:8px 0 0;color:var(--text)}

nav.toc{
  background:var(--surface);
  border:1px solid var(--border);
  border-left:5px solid var(--accent);
  border-radius:var(--radius);
  padding:18px 22px;margin:24px 0 32px;
}
nav.toc strong{display:block;margin-bottom:8px;color:var(--secondary);font-size:1.05rem}
nav.toc ol{margin:0;padding-left:22px}
nav.toc li{margin:4px 0}
nav.toc a{color:var(--secondary);text-decoration:none}
nav.toc a:hover{text-decoration:underline}

h2{
  font-size:1.55rem;line-height:1.25;margin:38px 0 14px;color:var(--secondary);
  padding:10px 16px;
  background:linear-gradient(90deg,var(--surface-alt),transparent);
  border-left:5px solid var(--primary);
  border-radius:0 8px 8px 0;
}
h3{color:var(--secondary);margin-top:24px;font-size:1.18rem}
p{margin:0 0 14px}

ul{padding-left:0;list-style:none;margin:12px 0 18px}
ul li{
  position:relative;padding:6px 0 6px 28px;
}
ul li::before{
  content:"›";position:absolute;left:8px;top:6px;
  color:var(--accent);font-weight:700;font-size:1.2rem;line-height:1.2;
}

ol{counter-reset:step;list-style:none;padding-left:0;margin:12px 0 18px}
ol li{
  counter-increment:step;position:relative;padding:6px 0 6px 42px;min-height:32px;
}
ol li::before{
  content:counter(step);
  position:absolute;left:0;top:4px;
  width:28px;height:28px;border-radius:50%;
  background:linear-gradient(135deg,var(--primary),var(--secondary));
  color:#fff;font-weight:700;font-size:.9rem;
  display:flex;align-items:center;justify-content:center;
}

.table-wrap{overflow-x:auto;border-radius:var(--radius);border:1px solid var(--border);margin:18px 0 24px}
table{width:100%;border-collapse:collapse;background:#fff}
thead th{
  background:linear-gradient(135deg,var(--primary),var(--secondary));
  color:#fff;font-weight:600;text-align:left;padding:12px 14px;font-size:.95rem;
}
tbody td{padding:11px 14px;border-top:1px solid var(--border);vertical-align:top;font-size:.96rem}
tbody tr:nth-child(even) td{background:var(--row-alt)}

details{
  background:var(--surface);
  border:1px solid var(--border);
  border-radius:10px;
  padding:0;margin:10px 0;
  overflow:hidden;
}
details summary{
  padding:14px 18px;cursor:pointer;font-weight:600;color:var(--secondary);
  list-style:none;display:flex;align-items:center;justify-content:space-between;gap:12px;
}
details summary::-webkit-details-marker{display:none}
details summary::after{
  content:"▼";color:var(--accent);font-size:.85rem;transition:transform .2s ease;
}
details[open] summary::after{transform:rotate(180deg)}
details[open] summary{background:var(--surface-alt)}
details .answer{padding:0 18px 16px;color:var(--text)}

.callout{
  background:linear-gradient(135deg,#ecfccb,#f7fee7);
  border:1px solid #bef264;border-left:5px solid var(--accent);
  border-radius:10px;padding:14px 18px;margin:18px 0;
}
.callout strong{color:#365314}

.figure{margin:22px 0;text-align:center}
.figure img,.figure svg{margin:0 auto;border-radius:10px}
.figure figcaption{font-size:.88rem;color:var(--muted);margin-top:8px}

.author-box{
  margin-top:44px;padding:22px;
  background:linear-gradient(135deg,var(--surface-alt),#ede9fe);
  border:1px solid var(--border);border-radius:var(--radius);
  display:flex;gap:18px;align-items:flex-start;flex-wrap:wrap;
}
.author-box img{width:80px;height:80px;border-radius:50%;border:3px solid #fff;box-shadow:var(--shadow)}
.author-box .who{flex:1;min-width:220px}
.author-box .who strong{display:block;font-size:1.1rem;color:var(--secondary)}
.author-box .who em{color:var(--muted);font-style:normal;font-size:.9rem}

footer.site{
  margin-top:60px;background:linear-gradient(135deg,var(--secondary),var(--primary));
  color:#e9d5ff;padding:32px 20px;
}
footer.site .wrap{max-width:1080px;margin:0 auto;display:flex;flex-wrap:wrap;gap:20px;justify-content:space-between}
footer.site a{color:#fff;text-decoration:none;margin-right:14px}
footer.site a:hover{text-decoration:underline}
footer.site small{display:block;margin-top:12px;color:#ddd6fe}

@media (max-width:700px){
  header.site .wrap{padding:10px 14px}
  nav.primary ul{gap:2px}
  nav.primary a{padding:6px 8px;font-size:.88rem}
  main{padding:16px 14px 40px}
  .hero{padding:24px 18px}
  h2{font-size:1.3rem;padding:8px 12px}
}
@media (min-width:980px){
  main{padding:32px 20px 80px}
}

/* a11y additions */
.skip-link{position:absolute;left:-9999px;top:0;background:var(--primary);color:#fff;padding:10px 16px;border-radius:4px;z-index:1000;text-decoration:none;font-weight:700}
.skip-link:focus{left:12px;top:12px}
a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
@media (prefers-reduced-motion: reduce){*,*::before,*::after{transition-duration:.01ms !important;animation-duration:.01ms !important}}