:root{--bg:#f6f8fb;--card:#fff;--ink:#0f1b2d;--muted:#5b6b82;--line:#e3e8f0;--brand:#0b6bcb;--brand2:#12a37f;--accent:#f5b301;--soft:#eef4fb;--err:#c62828;--ok:#14804a;--shadow:0 6px 24px rgba(15,27,45,.07)}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--bg:#0d1420;--card:#141e2e;--ink:#e8eef7;--muted:#9fb0c6;--line:#24324a;--brand:#4da3ff;--brand2:#2ccf9f;--soft:#182640;--shadow:0 6px 24px rgba(0,0,0,.35)}}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.6 Inter,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
a{color:var(--brand)}
img{max-width:100%}
.wrap{max-width:1140px;margin:0 auto;padding:0 16px}
/* header */
header.top{background:var(--card);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}
header.top .wrap{display:flex;align-items:center;gap:14px;min-height:60px}
.logo{display:flex;align-items:center;gap:9px;font-weight:800;font-size:20px;color:var(--ink);text-decoration:none;letter-spacing:-.3px}
.logo svg{width:32px;height:32px;flex:none}
.logo b{color:var(--brand)}
nav.main{display:flex;gap:4px;margin-left:auto;flex-wrap:wrap}
nav.main a{padding:8px 12px;border-radius:10px;color:var(--ink);text-decoration:none;font-weight:600;font-size:14.5px}
nav.main a:hover{background:var(--soft)}
.lang{position:relative}
.lang summary{list-style:none;cursor:pointer;padding:8px 12px;border:1px solid var(--line);border-radius:10px;font-weight:700;font-size:14px}
.lang summary::-webkit-details-marker{display:none}
.lang div{position:absolute;right:0;top:44px;background:var(--card);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);padding:6px;min-width:150px}
.lang a{display:block;padding:8px 10px;border-radius:8px;color:var(--ink);text-decoration:none;font-size:14.5px}
.lang a:hover,.lang a[aria-current]{background:var(--soft)}
@media(max-width:760px){nav.main{display:none}.lang{margin-left:auto}}
/* breadcrumbs + titles */
.crumbs{font-size:13.5px;color:var(--muted);margin:18px 0 6px}
.crumbs a{color:var(--muted);text-decoration:none}.crumbs a:hover{color:var(--brand)}
h1{font-size:clamp(26px,4vw,38px);line-height:1.15;margin:4px 0 8px;letter-spacing:-.5px}
.lead{color:var(--muted);font-size:17px;margin:0 0 18px;max-width:760px}
/* calculator layout */
.grid{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:24px;align-items:start}
@media(max-width:960px){.grid{grid-template-columns:1fr}}
.card{background:var(--card);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:20px}
#calc{display:grid;grid-template-columns:1fr 1fr;gap:20px}
@media(max-width:760px){#calc{grid-template-columns:1fr}}
#cf{display:flex;flex-wrap:wrap;gap:12px 12px;align-content:start}
.f{display:block;width:100%}.f.half{width:calc(50% - 6px)}
@media(max-width:420px){.f.half{width:100%}}
.f>span{display:block;font-size:13.5px;font-weight:600;color:var(--muted);margin-bottom:5px}
.in{display:flex;align-items:center;border:1.5px solid var(--line);border-radius:12px;background:var(--bg);overflow:hidden}
.in:focus-within{border-color:var(--brand);box-shadow:0 0 0 3px rgba(11,107,203,.15)}
.in input,.in select{flex:1;min-width:0;border:0;background:transparent;color:var(--ink);font:inherit;font-size:16px;padding:11px 12px;outline:0}
.in select{cursor:pointer}
.pre,.suf{padding:0 10px;color:var(--muted);font-weight:600;font-size:14px;white-space:nowrap}
.pre{padding-right:0}.suf{padding-left:0}
details.more{width:100%;border:1px dashed var(--line);border-radius:12px;padding:8px 12px}
details.more summary{cursor:pointer;font-weight:600;font-size:14px;color:var(--brand)}
details.more[open]{display:flex;flex-wrap:wrap;gap:12px}
details.more[open] summary{width:100%}
.chk{display:flex;gap:8px;align-items:center;font-size:14.5px;width:100%}
.btns{display:flex;gap:10px;width:100%;margin-top:4px}
.go{flex:1;padding:13px;border:0;border-radius:12px;background:var(--brand);color:#fff;font:inherit;font-weight:700;font-size:16px;cursor:pointer}
.go:hover{filter:brightness(1.07)}
.rs{padding:13px 16px;border:1.5px solid var(--line);border-radius:12px;background:transparent;color:var(--muted);font:inherit;font-weight:600;cursor:pointer}
#out{min-width:0}
.big{background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff;border-radius:16px;padding:16px 18px;margin-bottom:10px}
.big small{display:block;opacity:.9;font-weight:600;font-size:14px}
.big b{display:block;font-size:clamp(26px,4vw,34px);line-height:1.15;margin:2px 0;font-variant-numeric:tabular-nums}
.big em{font-style:normal;opacity:.92;font-size:14px}
.kv{display:flex;justify-content:space-between;gap:12px;padding:9px 2px;border-bottom:1px solid var(--line);font-size:15px}
.kv span{color:var(--muted)}.kv b{text-align:right;font-variant-numeric:tabular-nums}
.err{color:var(--err);font-weight:600}.ok{color:var(--ok);font-weight:700}
.split{margin:14px 0 6px}
.bar{display:flex;height:14px;border-radius:8px;overflow:hidden;background:var(--line)}
.bar i,.lg i{background:var(--brand)}.bar u,.lg u{background:var(--accent)}
.bar i,.bar u{display:block;height:100%}
.lg{display:flex;gap:16px;flex-wrap:wrap;font-size:13.5px;color:var(--muted);margin-top:6px}
.lg span{display:flex;align-items:center;gap:6px}.lg i,.lg u{display:inline-block;width:12px;height:12px;border-radius:3px}
.cols{display:flex;align-items:flex-end;gap:2px;height:140px;margin:14px 0 4px;padding-top:6px;border-bottom:1px solid var(--line)}
.cols div{flex:1;display:flex;flex-direction:column-reverse;height:100%}
.cols i{display:block;background:var(--brand);border-radius:0 0 2px 2px}.cols u{display:block;background:var(--accent);border-radius:2px 2px 0 0}
.tgl{margin-top:12px;background:none;border:1.5px solid var(--line);border-radius:10px;padding:8px 12px;color:var(--brand);font:inherit;font-weight:600;font-size:14px;cursor:pointer}
.tbl{max-height:360px;overflow:auto;margin-top:10px;border:1px solid var(--line);border-radius:12px}
table{width:100%;border-collapse:collapse;font-size:14px;font-variant-numeric:tabular-nums}
th,td{padding:8px 10px;text-align:right;border-bottom:1px solid var(--line);white-space:nowrap}
th:first-child,td:first-child{text-align:left}
th{position:sticky;top:0;background:var(--soft);font-size:13px}
.tag{display:inline-block;padding:2px 10px;border-radius:999px;font-weight:700;font-size:13px;background:#fff;color:#111}
.tag.c1{background:#cfe3ff}.tag.c2{background:#c9f2dc}.tag.c3{background:#ffe7b3}.tag.c4{background:#ffc9c9}
.gauge{position:relative;margin:16px 0 8px}
.gauge div{display:flex;height:12px;border-radius:8px;overflow:hidden}
.gauge i{display:block;height:100%}
.gauge .c1{background:#6aa8ff;width:14%}.gauge .c2{background:#2fbf71;width:26%}.gauge .c3{background:#f5b301;width:20%}.gauge .c4{background:#e5534b;width:40%}
.gauge b{position:absolute;top:-5px;width:4px;height:22px;background:var(--ink);border-radius:2px;transform:translateX(-50%)}
.gauge small{display:flex;justify-content:space-between;font-size:11.5px;color:var(--muted);margin-top:4px}
.pct{width:100%;display:grid;gap:14px}
.pr{border:1px solid var(--line);border-radius:14px;padding:12px}
.pr>b{display:block;margin-bottom:8px}
.pr .line{display:flex;align-items:flex-end;gap:8px;flex-wrap:wrap}
.pr .line .f{width:auto;flex:1;min-width:90px}
.pr .line>span{padding-bottom:11px;color:var(--muted);font-weight:700}
.pr output{min-width:110px;padding:11px 12px;border-radius:12px;background:var(--soft);font-weight:800;color:var(--brand);font-variant-numeric:tabular-nums}
#calc:has(.pct){grid-template-columns:1fr}
/* article */
article{margin-top:26px}
article h2{font-size:24px;margin:30px 0 8px;letter-spacing:-.3px}
article h3{font-size:18px;margin:20px 0 6px}
article p,article li{color:var(--ink)}
article .formula{background:var(--soft);border-radius:12px;padding:12px 14px;font-family:ui-monospace,Consolas,monospace;font-size:15px;overflow-x:auto}
.faq details{border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin:8px 0;background:var(--card)}
.faq summary{cursor:pointer;font-weight:700}
.note{font-size:13.5px;color:var(--muted);border-left:3px solid var(--line);padding-left:12px;margin-top:22px}
/* sidebar */
aside.side .card{padding:16px}
aside.side h3{font-size:15px;margin:0 0 8px}
aside.side ul{list-style:none;margin:0;padding:0}
aside.side li a{display:flex;gap:10px;align-items:center;padding:9px 8px;border-radius:10px;color:var(--ink);text-decoration:none;font-weight:600;font-size:14.5px}
aside.side li a:hover{background:var(--soft)}
aside.side .ad{margin-top:16px;min-height:250px}
/* home */
.hero{padding:40px 0 18px;text-align:center}
.hero h1{font-size:clamp(30px,5vw,48px)}
.hero p{color:var(--muted);font-size:18px;max-width:640px;margin:0 auto 22px}
.search{max-width:560px;margin:0 auto}
.search input{width:100%;padding:15px 18px;border:1.5px solid var(--line);border-radius:14px;font:inherit;font-size:17px;background:var(--card);color:var(--ink);box-shadow:var(--shadow);outline:0}
.search input:focus{border-color:var(--brand)}
.cat{margin:30px 0 8px;font-size:20px}
.tiles{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px}
.tile{display:flex;gap:14px;align-items:flex-start;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:16px;text-decoration:none;color:var(--ink);box-shadow:var(--shadow);transition:transform .15s,border-color .15s}
.tile:hover{transform:translateY(-2px);border-color:var(--brand)}
.tile .ic{font-size:26px;width:46px;height:46px;border-radius:12px;background:var(--soft);display:grid;place-items:center;flex:none}
.tile b{display:block;font-size:16px}.tile small{color:var(--muted);font-size:13.5px;line-height:1.4;display:block;margin-top:2px}
.why{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin:34px 0}
.why div{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:16px}
.why b{display:block;margin-bottom:4px}
/* plain pages */
.page{max-width:800px}
.page h2{font-size:21px;margin-top:26px}
/* footer */
footer{margin-top:50px;border-top:1px solid var(--line);background:var(--card);padding:26px 0;font-size:14px;color:var(--muted)}
footer .wrap{display:flex;flex-wrap:wrap;gap:10px 24px;justify-content:space-between}
footer nav{display:flex;flex-wrap:wrap;gap:8px 18px}
footer a{color:var(--muted);text-decoration:none}footer a:hover{color:var(--brand)}