:root{
  --bg:#f6f7f9;--surface:#fff;--surface-2:#f1f3f6;--text:#16181d;--muted:#5b6270;--line:#e3e6eb;
  --brand:#2463eb;--brand-ink:#fff;--brand-soft:#e8f0fe;--accent:#0f9d58;--warn:#b54708;--warn-soft:#fff4e5;
  --ok-soft:#e7f6ee;--radius:14px;--shadow:0 1px 2px rgba(16,24,40,.05),0 1px 3px rgba(16,24,40,.06);
  --font:"Pretendard Variable",Pretendard,-apple-system,BlinkMacSystemFont,"Apple SD Gothic Neo","Malgun Gothic",sans-serif;
}
@media (prefers-color-scheme:dark){
  :root{--bg:#0f1115;--surface:#171a21;--surface-2:#1e222b;--text:#e8eaef;--muted:#9aa3b2;--line:#2a2f3a;
  --brand:#5b9cff;--brand-ink:#0b1220;--brand-soft:#1a2740;--accent:#3ecf8e;--warn:#f5a524;--warn-soft:#2b2112;--ok-soft:#12291e;
  --shadow:none}
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font);font-size:16px;line-height:1.7;word-break:keep-all;overflow-wrap:anywhere}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%}
.wrap{max-width:1080px;margin:0 auto;padding:0 16px}
.skip{position:absolute;left:-999px}.skip:focus{left:16px;top:8px;background:var(--surface);padding:8px;z-index:10}

/* header */
.site-header{background:var(--surface);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:60px;gap:12px}
.logo{display:flex;align-items:center;gap:8px;font-weight:800;font-size:19px;color:var(--text);letter-spacing:-.02em}
.logo img{display:block}.logo span{color:var(--brand)}.logo b{color:var(--text);font-weight:800}
.logo:hover{text-decoration:none}
.logo-mark{width:30px;height:30px;border-radius:8px;background:var(--brand);color:var(--brand-ink);display:grid;place-items:center;font-size:16px;font-weight:800}
.nav{display:flex;gap:4px}
.nav a{color:var(--muted);padding:8px 12px;border-radius:8px;font-weight:600;font-size:15px}
.nav a:hover,.nav a[aria-current=page]{background:var(--surface-2);color:var(--text);text-decoration:none}
@media (max-width:560px){.nav a{padding:8px 8px;font-size:14px}.logo{font-size:17px}}

/* layout */
main{padding:28px 0 56px}
.breadcrumb{font-size:13px;color:var(--muted);margin-bottom:12px}
.breadcrumb a{color:var(--muted)}
h1{font-size:30px;line-height:1.3;letter-spacing:-.03em;margin:0 0 10px}
h2{font-size:22px;line-height:1.4;letter-spacing:-.02em;margin:40px 0 12px}
h3{font-size:18px;margin:28px 0 8px}
.lead{color:var(--muted);font-size:17px;margin:0 0 24px}
@media (max-width:560px){h1{font-size:25px}h2{font-size:20px}}
.grid-2{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:20px;align-items:start}
@media (max-width:860px){.grid-2{grid-template-columns:1fr}}

.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow)}
.card h2:first-child,.card h3:first-child{margin-top:0}

/* forms */
.form-row{margin-bottom:16px}
.form-row label,.form-row .label{display:block;font-weight:600;font-size:14px;margin-bottom:6px}
.hint{display:block;font-weight:400;color:var(--muted);font-size:13px;margin-top:4px}
input[type=text],input[type=number],input[type=date],select{width:100%;height:46px;border:1px solid var(--line);border-radius:10px;padding:0 12px;font:inherit;font-size:16px;background:var(--surface);color:var(--text)}
input:focus,select:focus{outline:2px solid var(--brand);outline-offset:0;border-color:transparent}
.input-unit{position:relative}
.input-unit input{padding-right:44px;text-align:right}
.input-unit span{position:absolute;right:12px;top:50%;transform:translateY(-50%);color:var(--muted);font-size:14px;pointer-events:none}
.inline{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.inline-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
@media (max-width:480px){.inline-3{grid-template-columns:1fr 1fr}}
.seg{display:flex;flex-wrap:wrap;gap:6px}
.seg label{display:inline-flex;align-items:center;margin:0;font-weight:600;font-size:14px;border:1px solid var(--line);border-radius:999px;padding:7px 14px;cursor:pointer;background:var(--surface)}
.seg input{position:absolute;opacity:0;pointer-events:none}
.seg label:has(input:checked){background:var(--brand);color:var(--brand-ink);border-color:var(--brand)}
.seg label:has(input:focus-visible){outline:2px solid var(--brand);outline-offset:2px}
.check{display:flex;gap:8px;align-items:flex-start;font-weight:500 !important;font-size:14px !important}
.check input{margin-top:5px}
.quick{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}
.quick button{border:1px solid var(--line);background:var(--surface-2);color:var(--text);border-radius:8px;padding:4px 10px;font:inherit;font-size:13px;cursor:pointer}
.btn{display:inline-flex;align-items:center;justify-content:center;height:48px;padding:0 22px;border-radius:10px;border:0;background:var(--brand);color:var(--brand-ink);font:inherit;font-weight:700;font-size:16px;cursor:pointer;width:100%}
.btn:hover{filter:brightness(1.05)}

/* results */
.result{position:sticky;top:76px}
.result-main{background:var(--brand-soft);border-radius:12px;padding:18px;margin-bottom:14px}
.result-main .k{font-size:14px;color:var(--muted);font-weight:600}
.result-main .v{font-size:32px;font-weight:800;letter-spacing:-.02em;line-height:1.3;font-variant-numeric:tabular-nums}
.result-main .s{font-size:14px;color:var(--muted)}
@media (max-width:560px){.result-main .v{font-size:27px}}
.rows{margin:0;padding:0;list-style:none}
.rows li{display:flex;justify-content:space-between;gap:12px;padding:9px 0;border-bottom:1px dashed var(--line);font-size:15px}
.rows li:last-child{border-bottom:0}
.rows li span:last-child{font-weight:700;font-variant-numeric:tabular-nums;text-align:right}
.rows li.total{border-top:2px solid var(--line);border-bottom:0;margin-top:4px;padding-top:12px}
.rows li.sub{padding-left:12px;color:var(--muted);font-size:14px}
.note{font-size:13px;color:var(--muted);margin-top:12px}
.badge{display:inline-block;font-size:12px;font-weight:700;padding:2px 8px;border-radius:999px;background:var(--surface-2);color:var(--muted)}
.alert{border-radius:10px;padding:12px 14px;font-size:14px;margin-top:12px}
.alert.warn{background:var(--warn-soft);color:var(--warn)}
.alert.ok{background:var(--ok-soft);color:var(--accent)}
.bar{display:flex;height:12px;border-radius:999px;overflow:hidden;background:var(--surface-2);margin:10px 0 4px}
.bar i{display:block;height:100%}
.legend{display:flex;flex-wrap:wrap;gap:10px;font-size:12px;color:var(--muted)}
.legend b{display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:4px;vertical-align:-1px}

/* tables & prose */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:12px;background:var(--surface);margin:12px 0}
table{width:100%;border-collapse:collapse;font-size:14px;font-variant-numeric:tabular-nums}
th,td{padding:10px 12px;border-bottom:1px solid var(--line);text-align:left;white-space:nowrap}
th{background:var(--surface-2);font-weight:700}
tr:last-child td{border-bottom:0}
td.num,th.num{text-align:right}
.prose{max-width:760px}
.prose p{margin:0 0 14px}
.prose ul,.prose ol{padding-left:22px;margin:0 0 14px}
.prose li{margin-bottom:6px}
.prose blockquote{margin:16px 0;padding:12px 16px;border-left:4px solid var(--brand);background:var(--surface);border-radius:0 10px 10px 0;color:var(--muted)}
.prose code{background:var(--surface-2);padding:1px 6px;border-radius:6px;font-size:.92em}
.formula{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:14px 16px;font-weight:600;margin:12px 0}
.faq details{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:0 16px;margin-bottom:8px}
.faq summary{cursor:pointer;font-weight:700;padding:14px 0;list-style:none}
.faq summary::-webkit-details-marker{display:none}
.faq summary::before{content:"Q. ";color:var(--brand)}
.faq details>div{padding:0 0 14px;color:var(--text)}

/* cards list */
.tool-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px}
.tool-card{display:block;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:18px;color:var(--text);box-shadow:var(--shadow);transition:border-color .15s}
.tool-card:hover{border-color:var(--brand);text-decoration:none}
.tool-card .ic{font-size:22px}
.tool-card strong{display:block;font-size:17px;margin:6px 0 2px}
.tool-card span{color:var(--muted);font-size:14px;line-height:1.5;display:block}
.guide-list{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:12px}
.guide-item{display:block;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:16px;color:var(--text)}
.guide-item:hover{border-color:var(--brand);text-decoration:none}
.guide-item strong{display:block;font-size:16px;line-height:1.45;margin:4px 0}
.guide-item span{color:var(--muted);font-size:14px;line-height:1.5;display:block}
.hero{padding:12px 0 8px}
.hero h1{font-size:34px}
@media (max-width:560px){.hero h1{font-size:27px}}
.stats{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin:18px 0 8px}
.stats div{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:12px 14px}
.stats b{display:block;font-size:18px;font-variant-numeric:tabular-nums}
.stats small{color:var(--muted);font-size:13px}
@media (max-width:720px){.stats{grid-template-columns:1fr 1fr}}
.meta{color:var(--muted);font-size:14px;margin-bottom:20px}
.toc{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px 18px;margin:0 0 24px}
.toc strong{font-size:14px}
.toc ol{margin:6px 0 0;padding-left:20px;font-size:15px}
.cta{display:flex;gap:12px;align-items:center;justify-content:space-between;flex-wrap:wrap;background:var(--brand-soft);border-radius:12px;padding:16px 18px;margin:24px 0}
.cta a.btn{width:auto;height:42px}
.ad-slot{margin:24px 0}

/* footer */
.site-footer{border-top:1px solid var(--line);background:var(--surface);padding:28px 0;font-size:14px;color:var(--muted)}
.site-footer nav{display:flex;flex-wrap:wrap;gap:6px 16px;margin-bottom:10px}
.site-footer a{color:var(--muted)}
.site-footer p{margin:4px 0}
@media print{.site-header,.site-footer,.ad-slot{display:none}}
.guide-item span.badge{display:inline-block;color:var(--muted)}