:root{
  --primary:#1e40af;
  --secondary:#1e3a8a;
  --accent:#94a3b8;
  --bg:#ffffff;
  --surface:#eff6ff;
  --surface-alt:#dbeafe;
  --text:#1e3a8a;
  --muted:#5b6a80;
  --border:#bfdbfe;
  --row-alt:#eff6ff;
  --radius:6px;
  --maxw:960px;
  --shadow:0 2px 8px rgba(30,64,175,0.08);
  --shadow-lg:0 6px 24px rgba(30,58,138,0.12);
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
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:var(--text);
  background:var(--bg);
  background-image:
    radial-gradient(circle at 15% 10%,rgba(30,64,175,0.05),transparent 40%),
    radial-gradient(circle at 85% 90%,rgba(148,163,184,0.06),transparent 45%);
}
@media (min-width:700px){body{font-size:18px}}
img,svg{max-width:100%;height:auto;display:block}
a{color:var(--primary);text-underline-offset:3px}
a:hover{color:var(--secondary)}
p{margin:0 0 1em}

/* Header */
.site-header{
  position:sticky;top:0;z-index:50;
  background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);
  color:#fff;
  box-shadow:var(--shadow-lg);
}
.header-inner{
  max-width:var(--maxw);margin:0 auto;
  padding:.7rem 1rem;
  display:flex;flex-wrap:wrap;align-items:center;gap:.75rem;
}
.brand{
  display:flex;align-items:center;gap:.6rem;
  color:#fff;text-decoration:none;font-weight:700;font-size:1.15rem;
}
.brand img{width:36px;height:36px;background:#fff;border-radius:8px;padding:3px}
nav.main-nav{margin-left:auto}
nav.main-nav ul{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:.15rem}
nav.main-nav a{
  color:#fff;text-decoration:none;
  display:block;padding:.4rem .7rem;
  border-radius:var(--radius);font-size:.94rem;
  transition:background .15s;
}
nav.main-nav a:hover{background:rgba(255,255,255,0.15)}

/* Hero */
.hero{
  background:linear-gradient(140deg,var(--surface) 0%,var(--surface-alt) 100%);
  padding:2.5rem 1rem 2rem;
  border-bottom:1px solid var(--border);
}
.hero-inner{max-width:var(--maxw);margin:0 auto}
.hero h1{
  font-size:1.6rem;line-height:1.35;margin:0 0 .5rem;
  color:var(--secondary);font-weight:700;
}
@media (min-width:700px){.hero h1{font-size:2.05rem}}
.byline{font-size:.92rem;color:var(--muted);margin:0 0 1rem}
.byline strong{color:var(--secondary)}
.hero-lead{font-size:1.06rem;color:var(--text);margin:0}

/* Main */
main{max-width:var(--maxw);margin:0 auto;padding:1.5rem 1rem 3rem}

/* Table of contents */
nav.toc{
  background:var(--surface);
  border-left:4px solid var(--primary);
  border-radius:var(--radius);
  padding:1rem 1.25rem;
  margin:1.5rem 0 2rem;
  box-shadow:var(--shadow);
}
nav.toc p{font-weight:700;margin:.1rem 0 .5rem;color:var(--secondary)}
nav.toc ol{margin:0;padding-left:1.4rem;color:var(--muted)}
nav.toc a{color:var(--primary);text-decoration:none}
nav.toc a:hover{text-decoration:underline}

/* Section headings */
h2{
  font-size:1.35rem;color:var(--secondary);
  border-left:5px solid var(--primary);
  background:linear-gradient(90deg,var(--surface) 0%,transparent 80%);
  padding:.55rem .85rem;
  margin:2.4rem 0 1rem;
  border-radius:0 var(--radius) var(--radius) 0;
  line-height:1.4;
}
@media (min-width:700px){h2{font-size:1.55rem}}
h3{font-size:1.15rem;color:var(--secondary);margin:1.6rem 0 .5rem}

/* Lists */
ul{list-style:none;padding-left:0;margin:0 0 1.2rem}
ul li{position:relative;padding-left:1.5rem;margin-bottom:.5rem}
ul li::before{
  content:"▸";position:absolute;left:.2rem;top:0;
  color:var(--primary);font-weight:700;
}
ol{counter-reset:ol-c;list-style:none;padding-left:0;margin:0 0 1.2rem}
ol li{
  counter-increment:ol-c;position:relative;
  padding-left:2.4rem;margin-bottom:.55rem;min-height:1.8rem;
}
ol li::before{
  content:counter(ol-c);
  position:absolute;left:0;top:.15rem;
  width:1.7rem;height:1.7rem;
  background:var(--primary);color:#fff;
  border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  font-size:.85rem;font-weight:700;
}

/* Table */
.table-wrap{overflow-x:auto;margin:1.2rem 0 1.6rem;border-radius:var(--radius);box-shadow:var(--shadow)}
table{
  border-collapse:collapse;width:100%;min-width:520px;
  background:#fff;
}
thead th{
  background:linear-gradient(135deg,var(--primary),var(--secondary));
  color:#fff;text-align:left;padding:.7rem .8rem;font-weight:700;
}
tbody td{padding:.65rem .8rem;border-bottom:1px solid var(--border);vertical-align:top}
tbody tr:nth-child(even){background:var(--row-alt)}
tbody tr:last-child td{border-bottom:0}

/* FAQ details */
details{
  border:1px solid var(--border);
  border-radius:var(--radius);
  padding:.75rem 1rem;
  margin-bottom:.6rem;
  background:#fff;
  transition:box-shadow .15s;
}
details[open]{box-shadow:var(--shadow);border-color:var(--primary)}
details summary{
  cursor:pointer;font-weight:700;
  color:var(--secondary);
  list-style:none;
  display:flex;justify-content:space-between;align-items:center;gap:.75rem;
}
details summary::-webkit-details-marker{display:none}
details summary::after{
  content:"▼";color:var(--primary);font-size:.85rem;
  transition:transform .2s;
}
details[open] summary::after{transform:rotate(180deg)}
details > p, details > ul, details > ol{margin-top:.65rem}

/* Author box */
.author-box{
  background:linear-gradient(135deg,var(--surface) 0%,var(--surface-alt) 100%);
  border:1px solid var(--border);
  border-radius:var(--radius);
  padding:1.2rem;
  margin:2.5rem 0 1rem;
  display:flex;gap:1rem;align-items:flex-start;flex-wrap:wrap;
  box-shadow:var(--shadow);
}
.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{color:var(--secondary);font-size:1.05rem}
.author-box .who .role{color:var(--primary);font-size:.9rem;margin:.1rem 0 .5rem}
.author-box p{margin:0;font-size:.94rem;color:var(--text)}

/* In-content figures */
figure.inline-figure{
  margin:1.6rem 0;
  background:var(--surface);
  border-radius:var(--radius);
  padding:1rem;
  border:1px solid var(--border);
  text-align:center;
}
figure.inline-figure figcaption{
  font-size:.9rem;color:var(--muted);margin-top:.6rem;
}

/* Callout */
.callout{
  border-left:4px solid var(--accent);
  background:var(--surface);
  padding:.85rem 1rem;
  margin:1.4rem 0;
  border-radius:0 var(--radius) var(--radius) 0;
}
.callout strong{color:var(--secondary)}

/* CTA button */
.cta{
  display:inline-block;
  padding:.7rem 1.4rem;
  background:linear-gradient(135deg,var(--primary),var(--secondary));
  color:#fff !important;
  text-decoration:none;
  border-radius:var(--radius);
  font-weight:700;
  box-shadow:var(--shadow);
  transition:transform .15s;
}
.cta:hover{transform:translateY(-2px)}

/* Footer */
footer.site-footer{
  background:var(--surface);
  border-top:1px solid var(--border);
  padding:2rem 1rem;
  color:var(--muted);
  font-size:.9rem;
}
.footer-inner{max-width:var(--maxw);margin:0 auto;display:flex;flex-wrap:wrap;gap:1.5rem;justify-content:space-between}
footer nav ul{display:flex;flex-wrap:wrap;gap:.75rem}
footer nav ul li{padding-left:0}
footer nav ul li::before{content:""}
footer a{color:var(--primary);text-decoration:none}
footer a:hover{text-decoration:underline}

/* Utility */
.small{font-size:.88rem;color:var(--muted)}
.responsible-block{
  background:linear-gradient(135deg,var(--surface-alt) 0%,var(--surface) 100%);
  border-radius:var(--radius);
  padding:1.2rem 1.3rem;
  border-left:5px solid var(--primary);
  margin:1.5rem 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}}