:root {
  --bg: #f7f8fa;
  --card: #ffffff;
  --text: #1b1f24;
  --muted: #5f6b7a;
  --line: #e3e7ec;
  --accent: #2f6fed;
  --accent-soft: #e8f0fe;
  --good: #1f8a4c;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111418;
    --card: #1a1e24;
    --text: #e8ebef;
    --muted: #9aa5b2;
    --line: #2b313a;
    --accent: #6b9bff;
    --accent-soft: #1d2a45;
    --good: #4cc27f;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Malgun Gothic", "Noto Sans KR", sans-serif;
  line-height: 1.6;
}
a { color: var(--accent); }
header, main, footer { max-width: 760px; margin: 0 auto; padding: 0 16px; }
header { padding-top: 20px; }
header .brand { font-weight: 700; font-size: 1.1rem; text-decoration: none; color: var(--text); }
nav { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0 20px; }
nav a {
  padding: 6px 12px; border-radius: 999px; background: var(--card);
  border: 1px solid var(--line); text-decoration: none; color: var(--text); font-size: .9rem;
}
nav a[aria-current="page"] { background: var(--accent); border-color: var(--accent); color: #fff; }
h1 { font-size: 1.5rem; margin: 8px 0 4px; }
.lead { color: var(--muted); margin: 0 0 20px; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  padding: 20px; margin-bottom: 16px;
}
.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 16px; }
@media (max-width: 560px) { .grid { grid-template-columns: 1fr; } }
label { display: block; font-size: .9rem; color: var(--muted); margin-bottom: 4px; }
input, select {
  width: 100%; padding: 10px 12px; font-size: 1rem; border-radius: 10px;
  border: 1px solid var(--line); background: var(--bg); color: var(--text);
}
.hint { font-size: .8rem; color: var(--muted); margin-top: 2px; }
button {
  margin-top: 16px; width: 100%; padding: 12px; font-size: 1rem; font-weight: 600;
  border: 0; border-radius: 10px; background: var(--accent); color: #fff; cursor: pointer;
}
.result { display: none; }
.result.show { display: block; }
.big { font-size: 1.8rem; font-weight: 700; color: var(--accent); margin: 4px 0 12px; }
.rows { display: grid; gap: 6px; }
.rows div { display: flex; justify-content: space-between; border-bottom: 1px dashed var(--line); padding-bottom: 6px; }
.rows span:last-child { font-weight: 600; }
details summary { cursor: pointer; margin-top: 12px; color: var(--accent); }
.table-wrap { overflow-x: auto; margin-top: 8px; }
table { width: 100%; border-collapse: collapse; font-size: .85rem; }
th, td { padding: 6px 8px; border-bottom: 1px solid var(--line); text-align: right; white-space: nowrap; }
th:first-child, td:first-child { text-align: center; }
.promo {
  background: var(--accent-soft); border: 1px solid var(--accent); border-radius: 14px;
  padding: 16px 20px; margin-bottom: 16px;
}
.promo strong { display: block; margin-bottom: 4px; }
.promo a.cta {
  display: inline-block; margin-top: 8px; padding: 8px 14px; border-radius: 8px;
  background: var(--accent); color: #fff; text-decoration: none; font-weight: 600;
}
.tools { display: grid; gap: 12px; }
.tools a { display: block; text-decoration: none; color: var(--text); }
.tools a .card { margin: 0; }
.tools a .card:hover { border-color: var(--accent); }
.note { font-size: .85rem; color: var(--muted); }
.note li { margin-bottom: 4px; }
footer { color: var(--muted); font-size: .8rem; padding-bottom: 32px; }