:root{
  --primary:#b91c1c;
  --secondary:#7f1d1d;
  --accent:#ca8a04;
  --bg:#ffffff;
  --surface:#fef2f2;
  --surface-alt:#fee2e2;
  --text:#7f1d1d;
  --muted:#5f6e7d;
  --border:#fecaca;
  --row-alt:#fef2f2;
  --radius:8px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:"Sarabun","IBM Plex Sans Thai","Noto Sans Thai",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  font-size:17px;
  line-height:1.75;
  color:#1f2937;
  background:var(--bg);
}
a{color:var(--primary);text-decoration:underline;text-underline-offset:2px}
a:hover{color:var(--secondary)}
img,svg{max-width:100%;height:auto;display:block}
.container{max-width:1080px;margin:0 auto;padding:0 20px}
header.site{
  position:sticky;top:0;z-index:20;
  background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);
  color:#fff;
  border-bottom:3px solid var(--accent);
  box-shadow:0 2px 6px rgba(127,29,29,.18);
}
header.site .row{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:12px 0;flex-wrap:wrap}
header.site .brand{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font-weight:700;font-size:1.15rem}
header.site .brand img{width:36px;height:36px;background:#fff;border-radius:6px;padding:3px}
nav.primary{display:flex;flex-wrap:wrap;gap:14px}
nav.primary a{color:#fff;text-decoration:none;font-weight:500;font-size:.98rem;padding:4px 8px;border-radius:4px}
nav.primary a:hover{background:rgba(255,255,255,.15)}
.hero{
  background:linear-gradient(135deg,var(--surface) 0%,var(--surface-alt) 100%);
  border-bottom:1px solid var(--border);
  padding:44px 0 36px;
}
h1{
  font-size:1.85rem;line-height:1.35;margin:0 0 14px;color:var(--secondary);
  font-weight:700;
}
.byline{color:var(--muted);font-size:.94rem;margin:0 0 14px}
.byline strong{color:var(--secondary)}
.intro p{font-size:1.05rem;margin:0 0 10px}
.cta-row{display:flex;flex-wrap:wrap;gap:10px;margin-top:18px}
.cta{
  display:inline-block;padding:11px 22px;border-radius:var(--radius);
  background:linear-gradient(135deg,var(--primary),var(--secondary));color:#fff;
  font-weight:600;text-decoration:none;border:0;
  box-shadow:0 3px 8px rgba(127,29,29,.25);
}
.cta.alt{background:linear-gradient(135deg,var(--accent),#a16207)}
.cta:hover{transform:translateY(-1px)}
main{padding:36px 0 56px}
section{margin:0 0 34px}
h2{
  font-size:1.42rem;line-height:1.4;margin:36px 0 14px;color:var(--secondary);
  border-left:5px solid var(--primary);
  padding:10px 14px;
  background:var(--surface);
  border-radius:0 var(--radius) var(--radius) 0;
}
h3{font-size:1.12rem;color:var(--secondary);margin:22px 0 10px}
p{margin:0 0 14px}
ul,ol{margin:0 0 16px;padding-left:24px}
ul li,ol li{margin-bottom:8px}
ul{list-style:none;padding-left:0}
ul li{position:relative;padding-left:24px}
ul li::before{content:"▸";position:absolute;left:0;color:var(--primary);font-weight:700}
ol{list-style:none;counter-reset:step;padding-left:0}
ol li{position:relative;padding-left:38px;counter-increment:step}
ol li::before{
  content:counter(step);
  position:absolute;left:0;top:2px;
  width:26px;height:26px;border-radius:50%;
  background:linear-gradient(135deg,var(--primary),var(--secondary));
  color:#fff;text-align:center;font-size:.85rem;line-height:26px;font-weight:700;
}
nav.toc{
  background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius);padding:16px 20px;margin:20px 0 28px;
}
nav.toc h2{
  all:unset;font-weight:700;color:var(--secondary);font-size:1.05rem;
  display:block;margin-bottom:8px;
}
nav.toc ol{padding-left:0}
nav.toc ol li{padding-left:30px;margin-bottom:4px}
.table-wrap{overflow-x:auto;margin:0 0 18px;border:1px solid var(--border);border-radius:var(--radius)}
table{width:100%;border-collapse:collapse;font-size:.96rem;background:var(--bg)}
thead th{
  background:linear-gradient(135deg,var(--primary),var(--secondary));color:#fff;
  padding:11px 12px;text-align:left;font-weight:600;
}
tbody td{padding:10px 12px;border-top:1px solid var(--border);vertical-align:top}
tbody tr:nth-child(odd) td{background:var(--row-alt)}
figure{margin:22px 0;text-align:center}
figure svg{margin:0 auto;max-width:100%}
figcaption{font-size:.9rem;color:var(--muted);margin-top:6px}
details{
  background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius);padding:12px 16px;margin-bottom:10px;
}
details summary{
  cursor:pointer;font-weight:600;color:var(--secondary);
  list-style:none;display:flex;justify-content:space-between;align-items:center;gap:12px;
}
details summary::-webkit-details-marker{display:none}
details summary::after{content:"▼";color:var(--primary);transition:transform .2s}
details[open] summary::after{transform:rotate(180deg)}
details p{margin:10px 0 0}
.author-box{
  background:linear-gradient(135deg,var(--surface),var(--surface-alt));
  border:1px solid var(--border);border-radius:var(--radius);
  padding:20px;display:flex;gap:16px;align-items:flex-start;margin:40px 0 20px;
}
.author-box img{width:72px;height:72px;border-radius:50%;background:#fff;flex:none}
.author-box h3{margin:0 0 4px;color:var(--secondary)}
.author-box p{margin:0;color:#374151;font-size:.96rem}
footer.site{
  background:var(--secondary);color:#fecaca;padding:30px 0 24px;margin-top:40px;
  border-top:4px solid var(--accent);
}
footer.site a{color:#fff;text-decoration:none;margin-right:14px;font-size:.95rem}
footer.site a:hover{text-decoration:underline}
footer.site .small{font-size:.85rem;color:#fca5a5;margin-top:10px}
.warning-box{
  background:#fef3c7;border-left:5px solid var(--accent);
  padding:14px 18px;border-radius:0 var(--radius) var(--radius) 0;margin:20px 0;
  color:#78350f;
}
.warning-box strong{color:#7f1d1d}
@media(min-width:700px){
  body{font-size:17px}
  h1{font-size:2.15rem}
  h2{font-size:1.55rem}
}
@media(min-width:980px){
  h1{font-size:2.35rem}
  header.site .row{padding:14px 0}
}

/* 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}}