:root{
  --bg:#fafaf7;--surface:#fff;--ink:#1c2321;--muted:#5b6662;--line:#e3e6e1;
  --brand:#0f766e;--brand-ink:#fff;--brand-soft:#e6f4f1;--warn:#b42318;--warn-soft:#fdeceb;
  --shadow:0 1px 2px rgba(0,0,0,.05),0 4px 16px rgba(0,0,0,.04);
}
@media (prefers-color-scheme:dark){
  :root{--bg:#121714;--surface:#1a211d;--ink:#e8ede9;--muted:#9aa7a1;--line:#2b352f;
    --brand:#35b3a5;--brand-ink:#08201d;--brand-soft:#16312d;--warn:#ff8a80;--warn-soft:#3a1d1b;
    --shadow:none}
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.65 system-ui,-apple-system,"Segoe UI",Roboto,"Noto Sans",sans-serif}
.wrap{max-width:1040px;margin:0 auto;padding:0 16px}
main.wrap{padding-top:1.5rem;padding-bottom:3rem}
a{color:var(--brand)}
a:hover{text-decoration-thickness:2px}
.skip{position:absolute;left:-999px;top:0;background:var(--brand);color:var(--brand-ink);padding:.5rem 1rem;z-index:10}
.skip:focus{left:8px;top:8px}
:focus-visible{outline:3px solid var(--brand);outline-offset:2px}

.site-header{background:var(--surface);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5}
.bar{display:flex;align-items:center;justify-content:space-between;gap:1rem;min-height:60px;flex-wrap:wrap;padding-top:.4rem;padding-bottom:.4rem}
.brand{display:flex;align-items:center;gap:.6rem;font-weight:700;font-size:1.15rem;color:var(--ink);text-decoration:none}
.logo{display:inline-grid;place-items:center;width:34px;height:34px;border-radius:9px;background:var(--brand);color:var(--brand-ink);font-size:.85rem;font-weight:800}
nav a{color:var(--ink);text-decoration:none;padding:.45rem .7rem;border-radius:8px;font-weight:500}
nav a:hover,nav a[aria-current]{background:var(--brand-soft);color:var(--brand)}

h1{font-size:clamp(1.7rem,4.5vw,2.45rem);line-height:1.2;margin:.3rem 0 .6rem;letter-spacing:-.01em}
h2{font-size:1.5rem;line-height:1.3;margin:2.2rem 0 .7rem}
h3{font-size:1.1rem;margin:.2rem 0 .4rem;line-height:1.35}
.lead{font-size:1.15rem;color:var(--muted);max-width:46rem}
.kicker{color:var(--brand);font-weight:700;text-transform:uppercase;letter-spacing:.06em;font-size:.8rem;margin:0}
.crumbs{font-size:.88rem;color:var(--muted);margin-bottom:.5rem}
.crumbs a{color:var(--muted)}
.byline{color:var(--muted);font-size:.92rem;margin:.2rem 0 1.4rem}

.prose{max-width:46rem}
.prose p,.prose li{margin:0 0 1.05rem}
.prose ul,.prose ol{padding-left:1.4rem;margin:0 0 1.2rem}
.prose li{margin-bottom:.45rem}
.prose h2{margin-top:2.4rem}
.prose h3{margin-top:1.6rem}
.prose blockquote{margin:1.4rem 0;padding:.2rem 1.1rem;border-left:4px solid var(--brand);background:var(--brand-soft);border-radius:0 8px 8px 0}
.prose code{background:var(--brand-soft);padding:.1rem .35rem;border-radius:5px;font-size:.92em}
.prose table{border-collapse:collapse;width:100%;margin:1.2rem 0;font-size:.95rem;display:block;overflow-x:auto}
.prose th,.prose td{border:1px solid var(--line);padding:.5rem .7rem;text-align:left;white-space:nowrap}
.prose th{background:var(--brand-soft)}
.guide{margin-top:2.2rem;padding-top:.2rem;border-top:1px solid var(--line)}

details{border:1px solid var(--line);border-radius:10px;background:var(--surface);margin:.6rem 0;padding:.15rem 1rem}
summary{cursor:pointer;font-weight:600;padding:.7rem 0}
details[open] summary{border-bottom:1px solid var(--line);margin-bottom:.7rem}

.try{background:var(--brand-soft);border:1px solid var(--line);border-radius:12px;padding:1rem 1.2rem;margin:2rem 0;max-width:46rem}
.try p{margin:.3rem 0 0}
.note-box{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:.8rem 1rem;color:var(--muted);font-size:.92rem;max-width:46rem}
.note-box.small{margin-top:1rem}

.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:1rem;margin:1rem 0 1.5rem}
.card{display:block;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:1.1rem 1.2rem;text-decoration:none;color:var(--ink);box-shadow:var(--shadow);transition:transform .12s,border-color .12s}
.card:hover{transform:translateY(-2px);border-color:var(--brand)}
.card h3{margin:.4rem 0}
.card p{margin:0;color:var(--muted);font-size:.93rem;line-height:1.5}
.tag{font-size:.72rem;font-weight:700;text-transform:uppercase;letter-spacing:.06em;color:var(--brand)}
.hero{padding:1.5rem 0 .5rem}
.why ul{padding-left:1.2rem;max-width:46rem}
.why li{margin-bottom:.6rem}

/* tools */
.tool-box{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:1.3rem;box-shadow:var(--shadow);margin:1.2rem 0}
.row{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:1rem}
.field{display:flex;flex-direction:column;gap:.3rem;margin-bottom:.9rem}
.field label{font-weight:600;font-size:.92rem}
input[type=number],input[type=text],input[type=date],select,textarea{width:100%;font:inherit;color:var(--ink);background:var(--bg);border:1px solid var(--line);border-radius:9px;padding:.6rem .75rem;min-height:44px}
input[type=checkbox]{width:20px;height:20px;accent-color:var(--brand)}
textarea.big{min-height:200px;resize:vertical;line-height:1.55}
.btn{display:inline-block;font:inherit;font-weight:600;border:0;cursor:pointer;background:var(--brand);color:var(--brand-ink);padding:.65rem 1.2rem;border-radius:10px;text-decoration:none;min-height:44px}
.btn:hover{filter:brightness(1.08)}
.btn.secondary{background:transparent;color:var(--brand);border:1px solid var(--brand)}
.results{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:.8rem;margin-top:1rem}
.result-card{background:var(--brand-soft);border-radius:11px;padding:.8rem 1rem}
.result-label{display:block;font-size:.8rem;color:var(--muted);font-weight:600}
.result-value{display:block;font-size:1.35rem;font-weight:700;word-break:break-word}
table.data{border-collapse:collapse;width:100%;font-size:.92rem;margin-top:.5rem}
table.data th,table.data td{border-bottom:1px solid var(--line);padding:.45rem .6rem;text-align:right;white-space:nowrap}
table.data th:first-child,table.data td:first-child{text-align:left}
table.data th{background:var(--brand-soft);position:sticky;top:0}
.note{color:var(--muted);font-size:.88rem;margin:.6rem 0 0}
.error{color:var(--warn);background:var(--warn-soft);border-radius:8px;padding:.5rem .8rem;margin:.6rem 0 0;font-weight:500}
.error:empty{display:none}

.site-footer{background:var(--surface);border-top:1px solid var(--line);padding:2rem 0 1.5rem;font-size:.93rem}
.cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:1.5rem}
.site-footer ul{list-style:none;padding:0;margin:.4rem 0 0}
.site-footer li{margin:.3rem 0}
.site-footer p{color:var(--muted);margin:.4rem 0}
.copy{margin-top:1.5rem;border-top:1px solid var(--line);padding-top:1rem;font-size:.85rem}
@media (max-width:560px){body{font-size:16.5px}.tool-box{padding:1rem}}
@media print{.site-header,.site-footer,.btn{display:none}}