:root{
  --bg:#f5f6f8; --card:#fff; --line:#e5e8ec; --ink:#1b2430; --muted:#6a7480;
  --brand:#4f46e5; --brand-2:#7c6cf0; --ok:#16a34a; --warn:#dc2626;
  --shadow:0 1px 2px rgba(16,24,40,.04),0 6px 20px rgba(16,24,40,.06);
  --r:14px;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:'Pretendard','Apple SD Gothic Neo','Malgun Gothic',system-ui,-apple-system,sans-serif;
  background:var(--bg);color:var(--ink);line-height:1.6;-webkit-text-size-adjust:100%}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:820px;margin:0 auto;padding:0 16px}

/* header */
header.site{position:sticky;top:0;z-index:20;background:rgba(245,246,248,.9);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.nav{max-width:820px;margin:0 auto;padding:12px 16px;display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.logo{display:flex;align-items:center;gap:9px;font-weight:800;font-size:18px;letter-spacing:-.02em;color:var(--ink)}
.logo:hover{text-decoration:none}
.logo .mark{width:28px;height:28px;border-radius:8px;background:linear-gradient(135deg,var(--brand),var(--brand-2));display:grid;place-items:center;color:#fff;font-weight:900;font-size:14px}
.nav .links{display:flex;gap:14px;margin-left:auto;font-size:14px;font-weight:600}
.nav .links a{color:var(--muted)}
.nav .links a.on,.nav .links a:hover{color:var(--ink)}

/* hero / headings */
.hero{padding:34px 0 8px;text-align:center}
.hero h1{font-size:26px;letter-spacing:-.03em;margin:0 0 8px}
.hero p{color:var(--muted);margin:0 auto;max-width:560px}
h1.page{font-size:23px;letter-spacing:-.02em;margin:26px 0 6px}
.lede{color:var(--muted);margin:0 0 20px}

/* ad slot */
.ad{margin:22px auto;max-width:728px;min-height:90px;border:1px dashed var(--line);border-radius:10px;display:grid;place-items:center;color:#aab2bd;font-size:12.5px;background:#fafbfc}

/* tool sections (home) */
.toolsec{scroll-margin-top:76px;margin-top:26px}
.sec-title{font-size:17px;letter-spacing:-.01em;margin:0 0 4px}
/* tool card grid (home) */
.grid{display:grid;grid-template-columns:1fr;gap:12px;margin:12px 0}
@media(min-width:560px){.grid{grid-template-columns:1fr 1fr}}
.tool{display:block;background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:16px 18px;box-shadow:var(--shadow)}
.tool:hover{text-decoration:none;transform:translateY(-1px);transition:transform .12s}
.tool .t{font-weight:800;font-size:16px;color:var(--ink)}
.tool .d{color:var(--muted);font-size:13.5px;margin-top:4px}
.tool .ic{font-size:22px}

/* panels & tools */
.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--shadow);padding:18px;margin:16px 0}
.drop{border:2px dashed #c9cfd8;border-radius:14px;padding:34px 16px;text-align:center;color:var(--muted);cursor:pointer;transition:.15s;background:#fbfcfd}
.drop.over{border-color:var(--brand);background:#f2f1fe;color:var(--brand)}
.drop b{color:var(--ink)}
.controls{display:flex;flex-wrap:wrap;gap:16px;align-items:flex-end;margin-top:16px}
.ctl{display:flex;flex-direction:column;gap:6px;font-size:13px;font-weight:700}
.ctl input[type=number],.ctl select{border:1px solid var(--line);border-radius:9px;padding:9px 11px;font-size:14px;font-family:inherit;min-width:120px}
.ctl input[type=range]{width:200px}
.chk{display:flex;align-items:center;gap:6px;font-size:13px;font-weight:600}
.btn{border:0;border-radius:10px;padding:11px 18px;font-weight:700;font-size:14px;cursor:pointer;font-family:inherit}
.btn.primary{background:var(--brand);color:#fff}
.btn.primary:disabled{opacity:.45;cursor:not-allowed}
.btn.ghost{background:#eceef3;color:var(--ink)}
.result{display:none;margin-top:16px}
.result.on{display:block}
.preview{display:flex;gap:16px;flex-wrap:wrap;align-items:center}
.preview img{max-width:220px;max-height:180px;border-radius:10px;border:1px solid var(--line);background:#fff}
.meta{font-size:14px}
.meta .row{display:flex;justify-content:space-between;gap:24px;padding:4px 0;border-bottom:1px solid var(--line)}
.meta .save{color:var(--ok);font-weight:800}
.hint{font-size:12.5px;color:var(--muted)}

/* content prose */
.prose{margin:26px 0}
.prose h2{font-size:18px;margin:24px 0 8px;letter-spacing:-.01em}
.prose h3{font-size:15px;margin:18px 0 6px}
.prose p,.prose li{color:#33404e}
.prose ul{padding-left:20px}
.faq dt{font-weight:800;margin-top:14px}
.faq dd{margin:4px 0 0;color:#33404e}

/* footer */
footer.site{border-top:1px solid var(--line);margin-top:40px;padding:28px 0;color:var(--muted);font-size:13px}
footer.site .fgrid{display:grid;grid-template-columns:1fr;gap:18px;margin-bottom:20px}
@media(min-width:560px){footer.site .fgrid{grid-template-columns:repeat(3,1fr)}}
footer.site .fcol h4{margin:0 0 8px;font-size:13px;color:var(--ink)}
footer.site .fcol ul{list-style:none;margin:0;padding:0}
footer.site .fcol li{margin:4px 0}
footer.site .fcol a{color:var(--muted)}
footer.site .fcol a:hover{color:var(--ink)}
footer.site .fbar{border-top:1px solid var(--line);padding-top:14px;line-height:1.7}
footer.site .fnav{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:6px}
footer.site .priv{font-weight:700;color:var(--ink)}
/* 글자수·계산기 등 문서도구 공용 */
.bigout{font-size:30px;font-weight:900;letter-spacing:-.02em;color:var(--brand)}
textarea.tb{width:100%;min-height:200px;border:1px solid var(--line);border-radius:12px;padding:14px;font-size:15px;font-family:inherit;line-height:1.7;resize:vertical}
textarea.tb:focus{outline:2px solid var(--brand-2);border-color:transparent}
.statgrid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-top:14px}
@media(min-width:560px){.statgrid{grid-template-columns:repeat(4,1fr)}}
.stat{background:#fafbfc;border:1px solid var(--line);border-radius:12px;padding:12px 14px}
.stat .k{font-size:12.5px;color:var(--muted);font-weight:600}
.stat .v{font-size:22px;font-weight:800;letter-spacing:-.02em;margin-top:2px}
.stat .sub{margin-top:1px}
.qrbox{display:grid;place-items:center;padding:16px;background:#fff;border:1px solid var(--line);border-radius:12px;margin-top:14px}
.qrbox canvas{max-width:100%;height:auto;image-rendering:pixelated}
/* 계산기 공용 */
.frow{display:flex;flex-wrap:wrap;gap:14px;align-items:flex-end}
.f{display:flex;flex-direction:column;gap:6px;font-size:13px;font-weight:700;margin-bottom:4px}
.f input,.f select{border:1px solid var(--line);border-radius:9px;padding:10px 12px;font-size:15px;font-family:inherit}
.f.full{width:100%}
.f.full input,.f.full select{width:100%}
.result-big{margin-top:16px;padding:16px 18px;background:linear-gradient(160deg,#eef2ff,#f5f3ff);border:1px solid #e0e3f5;border-radius:14px}
.result-big .k{font-size:13px;color:var(--muted);font-weight:700}
.result-big .v{font-size:30px;font-weight:900;letter-spacing:-.02em;color:var(--brand);margin-top:2px}
.bk{width:100%;border-collapse:collapse;margin-top:12px;font-size:14px}
.bk th,.bk td{padding:9px 6px;border-bottom:1px solid var(--line);text-align:right}
.bk th:first-child,.bk td:first-child{text-align:left;color:var(--muted);font-weight:600}
.bk tr.total td{font-weight:800;border-top:2px solid var(--line)}
.warnbox{margin-top:12px;font-size:12.5px;color:#8a5a00;background:#fff8e6;border:1px solid #ffe4a3;border-radius:10px;padding:10px 12px}
/* 텍스트 도구 공용 */
.twocol{display:grid;grid-template-columns:1fr;gap:12px}
@media(min-width:640px){.twocol{grid-template-columns:1fr 1fr}}
.opts{display:flex;flex-wrap:wrap;gap:10px 16px;margin:12px 0}
.opts label{display:flex;align-items:center;gap:6px;font-size:13.5px;font-weight:600}
.mono{font-family:'D2Coding','Consolas','Menlo',monospace;font-size:14px}
.diffout{white-space:pre-wrap;word-break:break-all;line-height:1.7;border:1px solid var(--line);border-radius:12px;padding:14px;background:#fff;max-height:460px;overflow:auto}
.diffout .add{background:#e5f6ea;color:#0a7d33}
.diffout .del{background:#fdeaea;color:#c0362b;text-decoration:line-through}
.diffout .same{color:#33404e}
.count-pill{display:inline-block;background:#eef1f4;border-radius:999px;padding:3px 10px;font-size:12.5px;font-weight:700;margin-right:6px}
.sigwrap{border:1px solid var(--line);border-radius:12px;background:#fff;
  background-image:linear-gradient(45deg,#f2f3f5 25%,transparent 25%),linear-gradient(-45deg,#f2f3f5 25%,transparent 25%),linear-gradient(45deg,transparent 75%,#f2f3f5 75%),linear-gradient(-45deg,transparent 75%,#f2f3f5 75%);
  background-size:18px 18px;background-position:0 0,0 9px,9px -9px,-9px 0;touch-action:none;overflow:hidden}
.sigwrap canvas{display:block;width:100%;height:auto;cursor:crosshair}
.tblprev{overflow-x:auto;margin-top:12px}
.tblprev table{border-collapse:collapse;font-size:14px}
.tblprev th,.tblprev td{border:1px solid var(--line);padding:6px 10px;text-align:left}
.tblprev th{background:#f4f5f8}
/* 유틸 도구 공용 */
.bigmono{font-family:'D2Coding','Consolas','Menlo',monospace;font-size:26px;font-weight:800;word-break:break-all;padding:14px 16px;background:#f7f8fa;border:1px solid var(--line);border-radius:12px;margin-top:12px}
.clock{font-family:'D2Coding','Consolas',monospace;font-size:52px;font-weight:800;letter-spacing:.02em;text-align:center;margin:8px 0}
.tabs{display:flex;gap:6px;background:#eceef1;padding:5px;border-radius:12px;margin-bottom:16px}
.tabs button{flex:1;border:0;background:transparent;padding:9px;border-radius:9px;font-weight:700;color:var(--muted);cursor:pointer;font-family:inherit;font-size:14px}
.tabs button.on{background:#fff;color:var(--ink);box-shadow:var(--shadow)}
.winners{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.winners .w{background:#eef2ff;color:var(--brand);border:1px solid #dfe3f7;border-radius:999px;padding:6px 14px;font-weight:700}
.meterbar{height:8px;border-radius:99px;background:#eceef3;overflow:hidden;margin-top:8px}
.meterbar>i{display:block;height:100%;width:0;transition:width .2s}
canvas.ladder{width:100%;height:auto;border:1px solid var(--line);border-radius:12px;background:#fff;margin-top:12px}
/* 가이드 아티클 */
.glist{display:grid;grid-template-columns:1fr;gap:12px;margin:18px 0}
@media(min-width:640px){.glist{grid-template-columns:1fr 1fr}}
.gcard{display:block;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:18px;box-shadow:var(--shadow)}
.gcard:hover{text-decoration:none;transform:translateY(-1px);transition:transform .12s}
.gcard .gt{font-weight:800;font-size:16px;color:var(--ink);letter-spacing:-.01em}
.gcard .gd{color:var(--muted);font-size:13.5px;margin-top:5px;line-height:1.55}
.article{max-width:720px}
.article .lead{font-size:16px;color:#33404e;margin:0 0 8px}
.article .toclink{display:inline-block;margin-top:6px;font-size:13px}
.article h2{margin-top:30px}
.relbox{margin-top:26px;padding:16px 18px;background:#f7f8fa;border:1px solid var(--line);border-radius:14px}
.relbox h3{margin:0 0 8px;font-size:14px}
.relbox a{display:inline-block;margin:2px 10px 2px 0;font-weight:600}
.badge{display:inline-flex;align-items:center;gap:6px;background:#e8f6ee;color:#137a3f;font-weight:700;font-size:12.5px;padding:5px 10px;border-radius:999px}