:root {
  --bg: #f6f8fb; --surface: #ffffff; --ink: #17222c; --ink-2: #4a5866; --line: #dde4ec;
  --brand: #1f5e8c; --brand-ink: #ffffff; --brand-soft: #e8f1f8; --accent: #b77905; --hl: #fff6e0;
  --code: #f0f4f8;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101418; --surface: #182028; --ink: #e6edf3; --ink-2: #a9b6c2; --line: #2a3642;
    --brand: #7fb7e2; --brand-ink: #0b2236; --brand-soft: #1b2c3b; --accent: #f2b134; --hl: #2b2614;
    --code: #121a21;
    color-scheme: dark;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 16px/1.65 system-ui, -apple-system, "Apple SD Gothic Neo", "Malgun Gothic", "Noto Sans KR", sans-serif;
  word-break: keep-all; overflow-wrap: anywhere;
}
a { color: var(--brand); }
.wrap { max-width: 980px; margin: 0 auto; padding: 0 16px; }
.muted { color: var(--ink-2); font-size: .9em; }

.top { background: var(--surface); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 5; }
.top-in { display: flex; align-items: center; justify-content: space-between; gap: 12px; height: 56px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; color: var(--ink); text-decoration: none; white-space: nowrap; }
.brand img { border-radius: 8px; }
.top nav { display: flex; align-items: center; gap: 14px; }
.top nav a:not(.btn) { color: var(--ink-2); text-decoration: none; font-size: .95em; }
@media (max-width: 420px) { .top nav a:not(.btn) { display: none; } }

.btn { display: inline-block; background: var(--brand); color: var(--brand-ink); text-decoration: none; font-weight: 700;
  padding: 12px 22px; border-radius: 12px; border: 2px solid var(--brand); }
.btn:hover { filter: brightness(1.08); }
.btn-ghost { background: transparent; color: var(--brand); }
.btn-sm { padding: 6px 14px; border-radius: 10px; font-size: .9em; }
.ctas { display: flex; flex-wrap: wrap; gap: 10px; margin: 20px 0 4px; }

main section { margin: 40px 0; }
.hero { margin-top: 40px; }
.hero-sm { margin-top: 20px; }
h1 { font-size: clamp(1.7rem, 4.5vw, 2.4rem); line-height: 1.25; margin: 0 0 10px; letter-spacing: -0.02em; }
h2 { font-size: 1.35rem; margin: 0 0 14px; letter-spacing: -0.01em; }
h2 small { font-weight: 400; color: var(--ink-2); font-size: .7em; }
h3 { font-size: 1.05rem; margin: 22px 0 10px; }
.lead { font-size: 1.12rem; color: var(--ink-2); margin: 0 0 8px; }

.pills { list-style: none; padding: 0; margin: 14px 0 0; display: flex; flex-wrap: wrap; gap: 8px; }
.pills li { background: var(--brand-soft); color: var(--ink); padding: 4px 12px; border-radius: 999px; font-size: .9em; }

.cat { color: var(--ink-2); font-size: .95rem; margin-top: 26px; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 12px; }
.card { display: flex; flex-direction: column; gap: 4px; background: var(--surface); border: 1px solid var(--line);
  border-radius: 14px; padding: 16px 18px; text-decoration: none; color: var(--ink); transition: border-color .15s; }
.card:hover { border-color: var(--brand); }
.card strong { font-size: 1.08rem; }
.card span { color: var(--ink-2); font-size: .93em; }
.card small { color: var(--accent); font-size: .8em; margin-top: 4px; }

.checks, .refs { padding-left: 1.2em; }
.checks li, .refs li { margin: 4px 0; }

.crumbs { margin-top: 18px; font-size: .88em; color: var(--ink-2); }
.crumbs a { color: var(--ink-2); }

.tbl { overflow-x: auto; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: .93em; }
th, td { text-align: left; padding: 9px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
thead th { background: var(--brand-soft); font-weight: 700; white-space: nowrap; }
tbody tr:last-child > * { border-bottom: 0; }
tbody th { font-weight: 600; min-width: 9em; }
td[rowspan] { border-left: 1px solid var(--line); }
.grp { display: inline-block; font-size: .78em; color: var(--ink-2); border: 1px solid var(--line); border-radius: 6px; padding: 0 5px; margin-right: 2px; font-weight: 400; }
.sym { font-family: "Cambria Math", "Times New Roman", serif; font-style: italic; color: var(--ink-2); font-weight: 400; }
.unit { color: var(--ink-2); font-size: .92em; }

.two { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
@media (max-width: 720px) { .two { grid-template-columns: 1fr; } }
.two h3 { margin-top: 0; }
.kv { margin: 0; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.kv div { display: flex; justify-content: space-between; gap: 12px; padding: 8px 14px; border-bottom: 1px solid var(--line); }
.kv div:last-child { border-bottom: 0; }
.kv dt { color: var(--ink-2); }
.kv dd { margin: 0; font-weight: 600; text-align: right; font-variant-numeric: tabular-nums; }
.kv .hl { background: var(--hl); }
.kv .hl dt { color: var(--ink); font-weight: 700; }
.kv .hl dd { font-weight: 800; }
.notices { padding-left: 1.2em; color: var(--accent); }

.steps { padding-left: 1.4em; }
.steps li { margin: 0 0 14px; }
.steps code { display: block; margin-top: 4px; background: var(--code); border: 1px solid var(--line); border-radius: 8px;
  padding: 6px 10px; font: .92em/1.5 ui-monospace, "Cascadia Mono", Consolas, monospace; white-space: pre-wrap; }
.steps code.sub { color: var(--ink-2); }
.steps .res { display: inline-block; margin-top: 4px; font-weight: 700; }

details { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 12px 16px; margin: 8px 0; }
summary { cursor: pointer; font-weight: 700; }
details p { margin: 8px 0 0; color: var(--ink-2); }

.cta-end { background: var(--brand-soft); border-radius: 16px; padding: 22px 22px 18px; }
.cta-end p { margin: 0; font-weight: 600; }

.doc { max-width: 760px; margin-top: 32px; }
.doc h2 { font-size: 1.12rem; margin-top: 32px; }
.doc .summary { background: var(--brand-soft); border-radius: 14px; padding: 14px 18px; margin: 18px 0; }
.doc .summary ul { margin: 6px 0 0; padding-left: 1.2em; }

.foot { border-top: 1px solid var(--line); margin-top: 56px; padding: 22px 0 36px; color: var(--ink-2); font-size: .88em; }
.foot p { margin: 4px 0; }
.foot a { color: var(--ink-2); }