:root {
  --color-primary: #0066cc;
  --color-primary-dark: #004999;
  --color-text: #1a1a1a;
  --color-text-muted: #555;
  --color-bg: #ffffff;
  --color-bg-alt: #f5f7fa;
  --color-border: #e1e4e8;
  --color-link: #0066cc;
  --color-link-hover: #004999;
  --font-body: 'Sarabun', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width: 760px;
  --max-width-wide: 1100px;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2.5rem;
  --space-2xl: 4rem;
  --radius: 8px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
}
@media (prefers-color-scheme: dark) {
  :root {
    --color-text: #e8e8e8;
    --color-text-muted: #a0a0a0;
    --color-bg: #121212;
    --color-bg-alt: #1e1e1e;
    --color-border: #303030;
    --color-link: #4a9eff;
    --color-link-hover: #7eb8ff;
  }
}
*,*::before,*::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { font-family: var(--font-body); font-size: 17px; line-height: 1.7; color: var(--color-text); background: var(--color-bg); margin: 0; padding: 0; -webkit-font-smoothing: antialiased; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-md); }
a { color: var(--color-link); text-decoration: none; transition: color 0.15s ease; }
a:hover, a:focus { color: var(--color-link-hover); text-decoration: underline; }
a:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; border-radius: 2px; }
img { max-width: 100%; height: auto; display: block; }
h1, h2, h3, h4 { line-height: 1.3; margin-top: 2em; margin-bottom: 0.5em; font-weight: 700; }
h1 { font-size: clamp(1.75rem, 4vw, 2.5rem); margin-top: 0; }
h2 { font-size: clamp(1.4rem, 3vw, 1.75rem); border-bottom: 2px solid var(--color-border); padding-bottom: 0.3em; }
h3 { font-size: clamp(1.15rem, 2.5vw, 1.3rem); }
p { margin: 0 0 1em; }
blockquote { border-left: 4px solid var(--color-primary); margin: 1.5em 0; padding: 0.5em 1em; background: var(--color-bg-alt); font-style: italic; }
ul, ol { padding-left: 1.5em; }
li { margin-bottom: 0.4em; }
code { background: var(--color-bg-alt); padding: 2px 6px; border-radius: 3px; font-size: 0.9em; }
pre { background: var(--color-bg-alt); padding: 1em; border-radius: var(--radius); overflow-x: auto; }
pre code { background: none; padding: 0; }
hr { border: none; border-top: 1px solid var(--color-border); margin: 2em 0; }
table { width: 100%; border-collapse: collapse; margin: 1.5em 0; font-size: 0.95em; }
th, td { border: 1px solid var(--color-border); padding: 0.6em 0.9em; text-align: left; }
th { background: var(--color-bg-alt); font-weight: 600; }
tbody tr:nth-child(even) { background: var(--color-bg-alt); }
.site-header { border-bottom: 1px solid var(--color-border); padding: var(--space-md) 0; background: var(--color-bg); position: sticky; top: 0; z-index: 100; backdrop-filter: blur(8px); }
.primary-nav { display: flex; justify-content: space-between; align-items: center; gap: var(--space-md); }
.logo { font-size: 1.4rem; font-weight: 700; color: var(--color-primary); text-decoration: none; }
.nav-links { list-style: none; display: flex; gap: var(--space-lg); margin: 0; padding: 0; }
.nav-links a { color: var(--color-text); }
@media (max-width: 600px) {
  .nav-links { gap: var(--space-md); font-size: 0.9rem; }
}
.breadcrumb { font-size: 0.85rem; color: var(--color-text-muted); margin: var(--space-md) 0; }
.breadcrumb ol { list-style: none; display: flex; flex-wrap: wrap; padding: 0; margin: 0; gap: 0.3em; }
.breadcrumb li { display: inline; }
.breadcrumb li + li::before { content: "›"; margin: 0 0.3em; color: var(--color-text-muted); }
.breadcrumb a { color: var(--color-text-muted); }
.breadcrumb [aria-current="page"] { color: var(--color-text); }
.article { padding: var(--space-md) 0 var(--space-2xl); }
.article-header { margin-bottom: var(--space-lg); }
.article-meta { display: flex; flex-wrap: wrap; gap: var(--space-md); font-size: 0.9rem; color: var(--color-text-muted); margin-top: var(--space-md); }
.meta-item { display: inline-flex; align-items: center; gap: 0.3em; }
.article-hero { margin: var(--space-lg) calc(-1 * var(--space-md)) var(--space-xl); }
.article-hero img { width: 100%; height: auto; border-radius: 0; aspect-ratio: 1200 / 630; object-fit: cover; }
@media (min-width: 760px) {
  .article-hero { margin: var(--space-lg) 0 var(--space-xl); }
  .article-hero img { border-radius: var(--radius); }
}
.article-body { font-size: 1.05rem; line-height: 1.75; }
.article-body img { margin: 1.5em 0; border-radius: var(--radius); }
.article-body a { text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px; }
.article-faq { margin-top: var(--space-2xl); padding-top: var(--space-lg); border-top: 1px solid var(--color-border); }
.article-faq dl { margin: 0; }
.article-faq dt { font-weight: 600; margin-top: 1.5em; font-size: 1.1rem; }
.article-faq dd { margin: 0.5em 0 0; padding: 0; color: var(--color-text-muted); }
.related-articles { margin-top: var(--space-2xl); padding: var(--space-lg); background: var(--color-bg-alt); border-radius: var(--radius); }
.related-articles h2 { margin-top: 0; border: none; padding: 0; font-size: 1.3rem; }
.related-list { list-style: none; padding: 0; margin: 0; display: grid; gap: var(--space-md); grid-template-columns: 1fr; }
@media (min-width: 600px) { .related-list { grid-template-columns: 1fr 1fr; }  }
.related-list a { display: block; padding: var(--space-md); background: var(--color-bg); border-radius: var(--radius); border: 1px solid var(--color-border); transition: transform 0.15s ease, box-shadow 0.15s ease; text-decoration: none; }
.related-list a:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.related-title { display: block; font-weight: 600; color: var(--color-text); margin-bottom: 0.3em; }
.related-excerpt { display: block; font-size: 0.85rem; color: var(--color-text-muted); }
.article-footer { margin-top: var(--space-2xl); padding-top: var(--space-lg); border-top: 1px solid var(--color-border); }
.article-tags { display: flex; flex-wrap: wrap; gap: var(--space-sm); margin-bottom: var(--space-md); }
.tag { display: inline-block; padding: 0.25em 0.7em; background: var(--color-bg-alt); border-radius: 999px; font-size: 0.85rem; color: var(--color-text-muted); text-decoration: none; }
.tag:hover { background: var(--color-primary); color: white; text-decoration: none; }
.article-share-prompt { color: var(--color-text-muted); font-size: 0.95rem; text-align: center; margin: var(--space-lg) 0; }
.site-footer { background: var(--color-bg-alt); padding: var(--space-xl) 0; margin-top: var(--space-2xl); border-top: 1px solid var(--color-border); }
.cross-site-nav { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-md); justify-content: center; margin-bottom: var(--space-md); }
.cross-site-label { margin: 0; color: var(--color-text-muted); font-size: 0.9rem; }
.cross-site-nav ul { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: var(--space-md); }
.cross-site-nav a { color: var(--color-link); font-size: 0.95rem; }
.copyright { text-align: center; color: var(--color-text-muted); font-size: 0.85rem; margin: 0; }
@media print {
  .site-header, .site-footer, .related-articles, .article-share-prompt { display: none !important; }
  body { font-size: 12pt; color: black; background: white; }
  a { color: black; text-decoration: underline; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: 0.8em; }
}