/* 레이아웃: 넓은 화면은 입력(왼쪽) + 계산기 액정 같은 결과판(오른쪽), 설명글은 읽기 좋은 720px 단 */
:root {
  --paper: #f3f4f7;
  --card: #ffffff;
  --ink: #0f1b2d;
  --muted: #5a6577;
  --line: #dfe3ea;
  --soft: #eaeef5;
  --accent: #2348c9;
  --key: #ffc53d;          /* 계산기 노란 버튼 */
  --key-ink: #2a1f00;
  --display: #0f1b2d;      /* 결과 액정 */
  --display-fg: #e6ecf7;
  --display-muted: #8e9bb3;
  --display-line: #2a3850;
  --display-num: #ffd25e;
  --warn: #c2412d;
  --warn-on-display: #ff9a86;
  --shadow: 0 1px 2px rgba(15, 27, 45, .06), 0 8px 24px rgba(15, 27, 45, .06);
  --font-body: "IBM Plex Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  --font-num: "IBM Plex Mono", ui-monospace, "Consolas", monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0c1220; --card: #141c2b; --ink: #e8edf5; --muted: #98a3b6; --line: #253046; --soft: #1a2436;
    --accent: #8fb0ff; --key: #ffc53d; --key-ink: #2a1f00;
    --display: #060a13; --display-fg: #e6ecf7; --display-muted: #8592ab; --display-line: #222d42; --display-num: #ffd25e;
    --warn: #ff8f7a; --warn-on-display: #ff9a86; --shadow: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.3);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0c1220; --card: #141c2b; --ink: #e8edf5; --muted: #98a3b6; --line: #253046; --soft: #1a2436;
  --accent: #8fb0ff; --key: #ffc53d; --key-ink: #2a1f00;
  --display: #060a13; --display-fg: #e6ecf7; --display-muted: #8592ab; --display-line: #222d42; --display-num: #ffd25e;
  --warn: #ff8f7a; --warn-on-display: #ff9a86; --shadow: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.3);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  word-break: keep-all;
  overflow-wrap: break-word;
}
a { color: var(--accent); }
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 2px;
}

.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}

/* 헤더 */
.site-header { background: var(--card); border-bottom: 1px solid var(--line); }
.site-header .wrap { display: flex; align-items: center; gap: 12px 24px; padding-block: 12px; flex-wrap: wrap; }
.logo { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 700; font-size: 1.2rem; letter-spacing: -0.03em; margin-right: auto; }
.logo svg { width: 34px; height: 34px; flex: none; }
.logo span { color: var(--muted); font-weight: 600; }
.site-nav { display: flex; gap: 4px; overflow-x: auto; scrollbar-width: none; max-width: 100%; }
.site-nav::-webkit-scrollbar { display: none; }
.site-nav a { flex: none; padding: 6px 12px; border-radius: 999px; color: var(--muted); text-decoration: none; font-size: 0.92rem; font-weight: 600; }
.site-nav a:hover { color: var(--ink); background: var(--soft); }
.site-nav a[aria-current="page"] { color: var(--key-ink); background: var(--key); }

/* 푸터 */
.site-footer { margin-top: 80px; background: var(--card); border-top: 1px solid var(--line); color: var(--muted); font-size: 0.88rem; }
.site-footer .wrap { padding-block: 28px 44px; display: grid; gap: 6px; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 4px 18px; margin-bottom: 6px; }
.site-footer a { color: var(--ink); text-decoration: none; font-weight: 600; }
.site-footer p { margin: 0; }

/* 본문 */
main { padding-block: 36px 0; }
main > p, main > ol, main > ul:not(.tools):not(.related), main > h2, main > h3, main > details,
main > .summary, main > .table-wrap, main > .formula, main > .lead { max-width: 760px; }
h1 { font-size: clamp(1.75rem, 5vw, 2.5rem); line-height: 1.25; margin: 0 0 10px; letter-spacing: -0.035em; text-wrap: balance; }
h2 { font-size: 1.35rem; line-height: 1.4; margin: 56px 0 14px; letter-spacing: -0.02em; text-wrap: balance; }
h3 { font-size: 1.05rem; margin: 28px 0 6px; }
p, ul, ol { margin: 0 0 14px; }
.lead { color: var(--muted); font-size: 1.05rem; margin-bottom: 24px; }
.asof {
  display: inline-flex; align-items: center; gap: 6px; font-size: 0.8rem; font-weight: 600;
  color: var(--ink); background: var(--card); border: 1px solid var(--line);
  padding: 3px 12px 3px 8px; border-radius: 999px; margin-bottom: 14px; letter-spacing: 0.01em;
}
.asof::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: #22a06b; }
.summary { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 16px 20px; margin: 0 0 24px; }
.summary p:last-child { margin: 0; }
.summary strong { background: linear-gradient(transparent 62%, color-mix(in srgb, var(--key) 55%, transparent) 62%); }

/* 계산기 */
.calc {
  background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 22px;
  display: grid; gap: 18px; box-shadow: var(--shadow); align-items: start;
}
@media (min-width: 880px) {
  .calc { grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); gap: 18px 28px; padding: 28px; }
  .calc > .fields, .calc > .check { grid-column: 1; }
  .calc > .result { grid-column: 2; grid-row: 1 / span 4; position: sticky; top: 16px; }
}
.fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; }
.field { display: grid; gap: 6px; min-width: 0; align-content: start; }
.field label { font-size: 0.9rem; font-weight: 700; }
.field .hint { font-size: 0.8rem; color: var(--muted); }
.field input[type="text"], .field input[type="date"], .field input[type="number"], .field select {
  font: inherit; font-family: var(--font-num); font-size: 1.05rem;
  width: 100%; min-height: 48px; padding: 10px 14px; border: 1.5px solid var(--line); border-radius: 10px;
  background: var(--paper); color: var(--ink); transition: border-color .15s, background .15s;
}
.field input:hover, .field select:hover { border-color: color-mix(in srgb, var(--accent) 40%, var(--line)); }
.field input:focus, .field select:focus { border-color: var(--accent); background: var(--card); outline: none; box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 18%, transparent); }
.field input[type="date"], .field select { font-family: var(--font-body); }
.check { display: flex; align-items: center; gap: 10px; font-size: 0.92rem; font-weight: 600; cursor: pointer; }
.check input { width: 20px; height: 20px; accent-color: var(--accent); }

/* 결과: 계산기 액정 */
.result {
  background: var(--display); color: var(--display-fg); border-radius: 14px; padding: 20px 22px 18px;
  box-shadow: inset 0 0 0 1px var(--display-line);
}
.result-head { display: grid; gap: 2px; }
.result-head .label { font-size: 0.82rem; color: var(--display-muted); letter-spacing: 0.04em; font-weight: 600; }
.result-head .big {
  font-family: var(--font-num); font-variant-numeric: tabular-nums; font-size: clamp(2rem, 7vw, 2.6rem);
  font-weight: 600; color: var(--display-num); letter-spacing: -0.03em; line-height: 1.2;
}
.result-sub { font-size: 0.86rem; color: var(--display-muted); margin: 6px 0 14px; }
.result .warn { color: var(--warn-on-display); }
.stub { list-style: none; padding: 14px 0 0; margin: 0; font-size: 0.93rem; border-top: 1px dashed var(--display-line); }
.stub li { display: flex; align-items: baseline; gap: 8px; padding: 4px 0; }
.stub .k { flex: none; color: var(--display-fg); }
.stub .dots { flex: 1; border-bottom: 1px dotted var(--display-line); transform: translateY(-4px); min-width: 16px; }
.stub .v { flex: none; font-family: var(--font-num); font-variant-numeric: tabular-nums; }
.stub .total { border-top: 1px solid var(--display-line); margin-top: 6px; padding-top: 10px; font-weight: 700; }
.stub .total .v { color: var(--display-num); }
.note { font-size: 0.8rem; color: var(--display-muted); margin: 12px 0 0; }
.warn { color: var(--warn); font-weight: 700; }
.result table { font-size: 0.9rem; }
.result th, .result td { border-bottom-color: var(--display-line); }
.result th { background: transparent; color: var(--display-muted); }

/* 표, 공식, FAQ */
.table-wrap { overflow-x: auto; margin: 0 0 16px; }
main > .table-wrap { background: var(--card); border: 1px solid var(--line); border-radius: 12px; }
table { border-collapse: collapse; width: 100%; font-size: 0.93rem; }
th, td { border-bottom: 1px solid var(--line); padding: 10px 14px; text-align: left; }
tr:last-child td { border-bottom: none; }
th { font-weight: 700; background: var(--soft); }
td.num { font-family: var(--font-num); font-variant-numeric: tabular-nums; text-align: right; white-space: nowrap; }
.formula { font-family: var(--font-num); font-size: 0.9rem; background: var(--card); border: 1px solid var(--line); border-left: 4px solid var(--key); padding: 12px 16px; border-radius: 8px; overflow-x: auto; }
details { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 14px 18px; margin-bottom: 8px; }
summary { cursor: pointer; font-weight: 700; list-style: none; display: flex; justify-content: space-between; gap: 12px; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; font-family: var(--font-num); color: var(--muted); font-size: 1.2rem; line-height: 1.4; }
details[open] summary::after { content: "−"; }
details p { margin: 10px 0 0; color: var(--muted); }

/* 메인 화면 */
.hero { display: grid; gap: 28px; align-items: center; padding-block: 8px 12px; }
@media (min-width: 880px) { .hero { grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: 48px; } }
.hero h1 { font-size: clamp(2rem, 6vw, 3.1rem); }
.hero h1 em { font-style: normal; background: var(--key); color: var(--key-ink); padding: 0 .18em; border-radius: 6px; }
.hero .lead { margin: 0; }
.hero-display { background: var(--display); color: var(--display-fg); border-radius: 18px; padding: 22px; box-shadow: var(--shadow); min-width: 0; }
.hero-display .row { display: flex; justify-content: space-between; gap: 12px; font-size: 0.88rem; color: var(--display-muted); padding: 7px 0; border-bottom: 1px dashed var(--display-line); }
.hero-display .row b { font-family: var(--font-num); color: var(--display-fg); font-weight: 600; white-space: nowrap; }
.hero-display .out { margin-top: 12px; font-size: 0.82rem; color: var(--display-muted); }
.hero-display .out strong { display: block; font-family: var(--font-num); font-size: clamp(1.8rem, 6vw, 2.3rem); color: var(--display-num); letter-spacing: -0.03em; line-height: 1.2; }
.hero-display a { display: inline-flex; margin-top: 14px; padding: 8px 14px; border-radius: 999px; background: var(--key); color: var(--key-ink); font-weight: 700; text-decoration: none; font-size: 0.9rem; }
.trust { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; padding: 0; list-style: none; }
.trust li { font-size: 0.82rem; font-weight: 600; color: var(--muted); background: var(--card); border: 1px solid var(--line); padding: 4px 12px; border-radius: 999px; }

.section-title { display: flex; align-items: baseline; gap: 10px; }
.section-title small { font-size: 0.85rem; color: var(--muted); font-weight: 600; }
.tools { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 12px; }
.tools a {
  display: grid; grid-template-columns: auto 1fr; gap: 4px 14px; align-items: start; height: 100%;
  padding: 18px; background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  color: var(--ink); text-decoration: none; transition: transform .15s, border-color .15s, box-shadow .15s;
}
.tools a:hover { border-color: var(--ink); transform: translateY(-2px); box-shadow: var(--shadow); }
.tools .ic { grid-row: span 2; width: 44px; height: 44px; border-radius: 12px; background: var(--key); color: var(--key-ink); display: grid; place-items: center; }
.tools .ic svg { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.tools .t { font-weight: 700; line-height: 1.4; }
.tools .d { font-size: 0.86rem; color: var(--muted); line-height: 1.5; }

.related { display: flex; flex-wrap: wrap; gap: 8px; padding: 0; list-style: none; }
.related a { display: inline-block; padding: 7px 14px; border: 1px solid var(--line); border-radius: 999px; text-decoration: none; font-size: 0.9rem; font-weight: 600; color: var(--ink); background: var(--card); }
.related a:hover { border-color: var(--ink); }

/* 광고 자리: 광고 승인 전에는 아무 공간도 차지하지 않는다 */
.ad-slot:empty { display: none; }
.ad-slot { margin: 28px 0; min-height: 100px; }

@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }

/* 쿠팡 파트너스 배너 */
.partner { margin: 24px 0 0; max-width: 720px; }
.partner-note { font-size: 0.78rem; color: var(--muted); margin: 0 0 6px; }
.partner-frame { background: var(--card); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.partner-frame iframe { display: block; width: 100%; max-width: 680px; height: 140px; border: 0; margin: 0 auto; }