:root{
  --bg:#f5f7fb; --card:#fff; --text:#1f2937; --muted:#6b7280; --line:#e5e7eb;
  --primary:#2563eb; --primary-weak:#eff4ff; --accent:#16a34a; --danger:#dc2626;
  --radius:14px;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);
  font-family:Pretendard,-apple-system,BlinkMacSystemFont,"Apple SD Gothic Neo","Malgun Gothic","Noto Sans KR",sans-serif;
  line-height:1.65;font-size:16px;word-break:keep-all}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}

/* header / footer */
.top{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}
.top-in{max-width:880px;margin:0 auto;padding:12px 16px;display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.logo{font-weight:800;font-size:20px;color:var(--text)}
.logo span{color:var(--primary)}
.top nav{display:flex;gap:4px;overflow-x:auto;flex:1;scrollbar-width:none}
.top nav::-webkit-scrollbar{display:none}
.top nav a{white-space:nowrap;padding:6px 10px;border-radius:8px;color:var(--muted);font-size:14px}
.top nav a.on,.top nav a:hover{background:var(--primary-weak);color:var(--primary);text-decoration:none}
footer{margin-top:48px;border-top:1px solid var(--line);background:#fff;color:var(--muted);font-size:13px}
footer .in{max-width:880px;margin:0 auto;padding:24px 16px}
footer a{color:var(--muted);margin-right:14px}

/* layout */
.wrap{max-width:880px;margin:0 auto;padding:24px 16px}
h1{font-size:26px;margin:8px 0 6px;line-height:1.3}
h2{font-size:20px;margin:32px 0 10px}
h3{font-size:17px;margin:20px 0 8px}
.lead{color:var(--muted);margin:0 0 20px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px;margin:16px 0;box-shadow:0 1px 2px rgba(0,0,0,.03)}
.card h2:first-child,.card h3:first-child{margin-top:0}

/* form */
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:14px}
label.f{display:block;font-size:14px;font-weight:600;color:#374151}
label.f .hint{font-weight:400;color:var(--muted);font-size:12px}
.inp{position:relative;margin-top:6px}
.inp input,.inp select{width:100%;padding:12px 44px 12px 14px;font-size:17px;border:1px solid #d1d5db;border-radius:10px;background:#fff;color:var(--text);font-family:inherit}
.inp select{padding-right:14px}
.inp input:focus,.inp select:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(37,99,235,.15)}
.inp .u{position:absolute;right:14px;top:50%;transform:translateY(-50%);color:var(--muted);font-size:14px;pointer-events:none}
.seg{display:flex;background:#f1f5f9;border-radius:10px;padding:4px;gap:4px;margin-bottom:16px}
.seg button{flex:1;border:0;background:transparent;padding:10px;border-radius:8px;font-size:15px;font-family:inherit;cursor:pointer;color:var(--muted)}
.seg button.on{background:#fff;color:var(--primary);font-weight:700;box-shadow:0 1px 3px rgba(0,0,0,.08)}
.btn{border:1px solid var(--line);background:#fff;border-radius:10px;padding:9px 14px;font-size:14px;cursor:pointer;font-family:inherit}
.btn:hover{border-color:var(--primary);color:var(--primary)}
.chips{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}
.chips button{border:1px solid var(--line);background:#fff;border-radius:999px;padding:4px 10px;font-size:13px;cursor:pointer;font-family:inherit;color:var(--muted)}
.chips button:hover{border-color:var(--primary);color:var(--primary)}

/* result */
.result{margin-top:18px;background:var(--primary-weak);border-radius:12px;padding:18px}
.result .big{font-size:28px;font-weight:800;color:var(--primary);line-height:1.3}
.result .big small{font-size:15px;font-weight:600;color:var(--muted);margin-left:6px}
.result .label{font-size:14px;color:var(--muted)}
.rows{margin-top:12px;border-top:1px dashed #c7d2fe}
.rows div{display:flex;justify-content:space-between;gap:12px;padding:8px 0;border-bottom:1px dashed #dbe3fb;font-size:15px}
.rows div:last-child{border-bottom:0}
.rows b{font-weight:700}
.up{color:var(--danger)} .down{color:var(--primary)} .good{color:var(--accent)}
.note{font-size:13px;color:var(--muted);margin-top:10px}

table.t{width:100%;border-collapse:collapse;font-size:14px}
table.t th,table.t td{border-bottom:1px solid var(--line);padding:8px 6px;text-align:right}
table.t th:first-child,table.t td:first-child{text-align:left}
table.t th{background:#f8fafc;color:#374151;font-weight:600}
.scroll{overflow-x:auto}
details summary{cursor:pointer;color:var(--primary);font-weight:600;margin-top:14px}

/* content */
.content p,.content li{color:#374151}
.content .formula{background:#f8fafc;border:1px solid var(--line);border-radius:10px;padding:12px 14px;font-size:15px}
.faq h3{margin-top:18px}

/* ad placeholder */
.ad{display:none}

/* home */
.hero{padding:16px 0 4px}
.hero h1{font-size:30px}
.tiles{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:14px;margin-top:12px}
.tile{display:block;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:18px;color:var(--text);transition:.15s}
.tile:hover{border-color:var(--primary);transform:translateY(-2px);text-decoration:none;box-shadow:0 6px 18px rgba(37,99,235,.08)}
.tile .ic{font-size:26px}
.tile b{display:block;font-size:17px;margin:6px 0 2px}
.tile span{color:var(--muted);font-size:14px}

@media (max-width:560px){
  h1{font-size:22px}.hero h1{font-size:24px}
  .card{padding:16px}
  .result .big{font-size:24px}
}