:root {
  --blue: #0b2f6b;
  --blue-2: #153d82;
  --gold: #c99a36;
  --gold-soft: #f2dfab;
  --ink: #12203b;
  --muted: #5c687f;
  --line: #e8dfca;
  --bg: #fbfaf6;
  --white: #fff;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Tahoma, "Noto Sans Thai", system-ui, sans-serif;
  color: var(--ink);
  background:
    linear-gradient(135deg, rgba(11,47,107,.07), transparent 34%),
    linear-gradient(315deg, rgba(201,154,54,.14), transparent 30%),
    var(--bg);
}
a { color: var(--blue); text-decoration: none; }
a:hover { color: #8a641f; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding: 14px clamp(18px, 4vw, 50px);
  background: rgba(255,255,255,.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}
.brand { display: inline-flex; align-items: center; gap: 12px; font-weight: 900; color: var(--blue); }
.brand img { width: 44px; height: 44px; object-fit: contain; }
nav { display: flex; flex-wrap: wrap; gap: 10px; justify-content: flex-end; }
nav a { padding: 8px 12px; border-radius: 999px; border: 1px solid var(--line); background: #fff; font-weight: 800; }
main { width: min(1180px, calc(100% - 32px)); margin: 0 auto; }
.hero {
  min-height: 560px;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, .95fr);
  gap: clamp(24px, 5vw, 56px);
  align-items: center;
  padding: clamp(36px, 6vw, 78px) 0 32px;
}
.hero-copy h1 { margin: 8px 0 18px; color: var(--blue); font-size: clamp(34px, 5.8vw, 70px); line-height: 1.08; }
.hero-copy p { font-size: clamp(17px, 2vw, 21px); color: var(--muted); line-height: 1.82; }
.eyebrow { margin: 0; color: #9a711f; font-weight: 900; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 26px; }
.button {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  min-height: 46px;
  padding: 12px 18px;
  border: 1px solid var(--gold);
  border-radius: 8px;
  font-weight: 900;
}
.button.primary, .button.full { background: var(--blue); color: #fff; border-color: var(--blue); box-shadow: 0 12px 28px rgba(11,47,107,.18); }
.button.ghost { background: #fff; color: var(--blue); }
.button.full { width: 100%; margin-top: 18px; }
.hero-image { display: block; aspect-ratio: 4 / 3; border-radius: 8px; overflow: hidden; border: 1px solid var(--line); background: #fff; box-shadow: 0 24px 55px rgba(11,47,107,.18); }
.hero-image img, .image-strip img { width: 100%; height: 100%; object-fit: cover; display: block; }
.calculator, .article-card, .side-panel, .faq, .related, .topics {
  margin: 22px 0;
  padding: clamp(20px, 3vw, 32px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.94);
  box-shadow: 0 14px 36px rgba(19,33,59,.07);
}
h2 { color: var(--blue); margin: 4px 0 18px; }
.calc-row { display: grid; grid-template-columns: repeat(6, minmax(105px, 1fr)) minmax(260px, 1.6fr); gap: 10px; align-items: end; }
.calc-row label { font-size: 14px; font-weight: 900; color: var(--blue); }
.calc-row input { display: block; width: 100%; min-height: 44px; margin-top: 6px; border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px; font: inherit; }
.calc-result { min-height: 44px; display: flex; align-items: center; justify-content: center; padding: 10px; border-radius: 8px; background: linear-gradient(135deg, var(--blue), var(--blue-2)); color: #fff; font-weight: 900; }
.note { color: var(--muted); font-size: 14px; margin-bottom: 0; }
.content-grid { display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 22px; align-items: start; }
.article-card p, .side-panel li, .faq p, .info-band p { line-height: 1.85; color: var(--muted); }
.image-strip { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 22px; }
.image-strip a { aspect-ratio: 16 / 10; border-radius: 8px; overflow: hidden; border: 1px solid var(--line); }
.area-list { display: grid; gap: 10px; padding: 0; margin: 0; list-style: none; }
.area-list li { padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: #f8f2e4; }
.info-band { margin: 22px 0; padding: clamp(24px, 4vw, 38px); border-radius: 8px; background: linear-gradient(135deg, var(--blue), #061b40); color: #fff; }
.info-band h2, .info-band h3 { color: #fff; }
.info-band p { color: #e7edf8; }
.columns { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.columns > div { border-top: 3px solid var(--gold); padding-top: 12px; }
details { margin-top: 10px; padding: 14px 16px; border: 1px solid var(--line); border-radius: 8px; background: #fff; }
summary { cursor: pointer; font-weight: 900; color: var(--blue); }
.link-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.topic-group { margin-top: 26px; }
.topic-group h3 { color: #8a641f; border-bottom: 2px solid var(--gold-soft); padding-bottom: 8px; }
.topic-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.link-grid a, .topic-list a { display: flex; gap: 10px; align-items: flex-start; min-height: 54px; padding: 12px; border: 1px solid var(--line); border-radius: 8px; background: #fff; font-weight: 800; line-height: 1.5; }
.topic-list span { flex: 0 0 auto; min-width: 34px; height: 34px; display: inline-flex; align-items: center; justify-content: center; border-radius: 999px; background: var(--blue); color: #fff; font-size: 13px; }
footer { width: min(1180px, calc(100% - 32px)); margin: 34px auto 24px; padding-top: 24px; border-top: 1px solid var(--line); display: flex; gap: 14px; align-items: center; color: var(--muted); }
footer img { width: 42px; height: 42px; object-fit: contain; }
@media (max-width: 980px) {
  .hero, .content-grid, .columns { grid-template-columns: 1fr; }
  .hero { min-height: auto; }
  .calc-row { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .calc-result { grid-column: 1 / -1; }
  .topic-list, .link-grid { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .site-header { flex-direction: column; align-items: flex-start; }
  .hero-copy h1 { font-size: 34px; }
  .calc-row, .image-strip { grid-template-columns: 1fr; }
  footer { align-items: flex-start; }
}