:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-muted: #4a5568;
  --color-border: #e2e8f0;
  --color-accent: #2d3748;
  --color-link: #2b6cb0;
  --color-card: #f7fafc;
  --max-width: 720px;
  --radius: 8px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f172a;
    --color-text: #f1f5f9;
    --color-muted: #94a3b8;
    --color-border: #1e293b;
    --color-accent: #cbd5e1;
    --color-link: #60a5fa;
    --color-card: #1e293b;
  }
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo",
    "Pretendard", "Malgun Gothic", "맑은 고딕", "Helvetica Neue", Arial, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  font-size: 16px;
  word-break: keep-all;
  overflow-wrap: break-word;
  padding: 24px 16px 64px;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
}

header.page-header {
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 16px;
  margin-bottom: 28px;
}

header.page-header .eyebrow {
  font-size: 13px;
  color: var(--color-muted);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

h1 {
  font-size: 26px;
  font-weight: 700;
  margin-top: 8px;
  letter-spacing: -0.02em;
  line-height: 1.3;
}

h2 {
  font-size: 19px;
  font-weight: 700;
  margin-top: 36px;
  margin-bottom: 12px;
  color: var(--color-accent);
  letter-spacing: -0.01em;
}

h3 {
  font-size: 15px;
  font-weight: 600;
  margin-top: 20px;
  margin-bottom: 8px;
  color: var(--color-accent);
}

p {
  margin-bottom: 12px;
  color: var(--color-text);
}

ul, ol {
  margin: 8px 0 12px 22px;
}

li {
  margin-bottom: 6px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0;
  font-size: 14px;
}

th, td {
  text-align: left;
  padding: 10px 12px;
  border: 1px solid var(--color-border);
  vertical-align: top;
}

th {
  background: var(--color-card);
  font-weight: 600;
  color: var(--color-accent);
}

a {
  color: var(--color-link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.last-updated {
  font-size: 13px;
  color: var(--color-muted);
  margin-top: 8px;
}

.callout {
  background: var(--color-card);
  border-left: 3px solid var(--color-link);
  padding: 14px 16px;
  border-radius: var(--radius);
  margin: 16px 0;
  font-size: 14px;
}

.callout strong {
  color: var(--color-accent);
}

.contact-card {
  background: var(--color-card);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin-top: 16px;
  font-size: 15px;
}

.contact-card dt {
  font-weight: 600;
  color: var(--color-muted);
  font-size: 13px;
  margin-top: 8px;
}

.contact-card dt:first-child {
  margin-top: 0;
}

.contact-card dd {
  margin-left: 0;
}

.toc {
  background: var(--color-card);
  border-radius: var(--radius);
  padding: 14px 20px;
  margin: 20px 0 32px;
  font-size: 14px;
}

.toc h2 {
  font-size: 14px;
  margin: 0 0 8px;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.toc ol {
  margin: 0 0 0 20px;
  columns: 2;
  column-gap: 24px;
}

.toc li {
  margin-bottom: 4px;
  break-inside: avoid;
}

.toc a {
  color: var(--color-text);
}

footer {
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--color-border);
  text-align: center;
  font-size: 13px;
  color: var(--color-muted);
}

footer a {
  color: var(--color-muted);
  margin: 0 8px;
}

.home-grid {
  display: grid;
  gap: 12px;
  margin-top: 24px;
}

.home-card {
  display: block;
  background: var(--color-card);
  padding: 20px;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.home-card:hover {
  text-decoration: none;
  border-color: var(--color-link);
  transform: translateY(-1px);
}

.home-card .card-title {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 4px;
}

.home-card .card-desc {
  font-size: 14px;
  color: var(--color-muted);
}

@media (max-width: 480px) {
  body { padding: 20px 14px 56px; font-size: 15px; }
  h1 { font-size: 22px; }
  h2 { font-size: 17px; margin-top: 28px; }
  table { font-size: 13px; }
  th, td { padding: 8px 10px; }
  .toc ol { columns: 1; }
}