:root{--bg:#f6f8fa;--card:#fff;--ink:#14202b;--muted:#566877;--brand:#0b5563;--brand-ink:#fff;--accent:#d9560b;--line:#dce3e9;--soft:#e8f2f4;--ok:#17714a;--warn-bg:#fff4e0;--warn:#8a4b00;--bad:#b3261e;--shadow:0 1px 2px rgba(16,32,43,.06),0 4px 14px rgba(16,32,43,.05)}
@media (prefers-color-scheme:dark){:root{--bg:#0d1318;--card:#151d25;--ink:#e7eef3;--muted:#9bafbd;--brand:#59c2d6;--brand-ink:#06242b;--accent:#ff9a57;--line:#26323d;--soft:#122a31;--ok:#5fd19b;--warn-bg:#2d2312;--warn:#ffc778;--bad:#ff8a80;--shadow:none}}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.65 system-ui,-apple-system,"Segoe UI",Roboto,"Noto Sans","Hiragino Sans","Hiragino Kaku Gothic ProN","PingFang SC","Microsoft YaHei","Noto Sans CJK SC","Noto Sans CJK JP",sans-serif;overflow-wrap:break-word}
img,svg{max-width:100%}
a{color:var(--brand)}
a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
.skip{position:absolute;left:-999px;top:0;background:var(--brand);color:var(--brand-ink);padding:10px 14px;z-index:99}
.skip:focus{left:8px;top:8px}
.wrap{width:100%;max-width:1040px;margin:0 auto;padding:0 16px}
.narrow{max-width:760px}
/* header */
.hdr{background:var(--card);border-bottom:1px solid var(--line)}
.hdr .wrap{display:flex;align-items:center;gap:8px;min-height:60px;flex-wrap:wrap}
@media (max-width:420px){.logo{font-size:17px}.logo svg{width:28px;height:28px}.lang summary{padding:0 10px}}
.logo{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font-weight:700;font-size:18px;letter-spacing:-.01em;min-height:44px}
.logo svg{width:32px;height:32px;flex:none}
.logo span i{font-style:normal;color:var(--accent)}
.spacer{flex:1}
.menu-btn{display:none;min-height:44px;min-width:44px;justify-content:center;font-size:20px;border:1px solid var(--line);background:var(--card);color:var(--ink);border-radius:10px;font:inherit;font-size:15px;padding:0 12px;cursor:pointer}
.nav{display:flex;flex-wrap:wrap;gap:2px 4px;width:100%;padding:4px 0 10px}
.nav a{display:inline-flex;align-items:center;min-height:44px;padding:0 10px;border-radius:8px;text-decoration:none;color:var(--ink);font-size:15px}
.nav a:hover,.nav a[aria-current=page]{background:var(--soft);color:var(--brand)}
.lang{position:relative}
.lang summary{list-style:none;min-height:44px;display:flex;align-items:center;gap:6px;padding:0 12px;border:1px solid var(--line);border-radius:10px;cursor:pointer;font-size:15px;background:var(--card)}
.lang summary::-webkit-details-marker{display:none}
.lang ul{position:absolute;right:0;top:48px;z-index:20;margin:0;padding:6px;list-style:none;background:var(--card);border:1px solid var(--line);border-radius:12px;box-shadow:0 8px 24px rgba(0,0,0,.15);min-width:160px}
.lang li a{display:flex;align-items:center;min-height:44px;padding:0 12px;border-radius:8px;text-decoration:none;color:var(--ink)}
.lang li a:hover,.lang li a[aria-current=true]{background:var(--soft)}
html.js .hdr .nav{display:none}
html.js .hdr .nav.open{display:flex}
html.js .menu-btn{display:inline-flex;align-items:center;gap:6px}
@media (min-width:860px){
 .hdr .wrap{flex-wrap:nowrap}
 html.js .hdr .nav,.hdr .nav{display:flex;width:auto;padding:0;margin-left:12px}
 html.js .menu-btn{display:none}
 .spacer{flex:1}
 .nav{order:2}
 .lang{order:3}
}
@media (min-width:860px){.hdr .spacer{display:none}.nav{flex:1}}
/* hero + sections */
.hero{padding:28px 0 8px}
.hero h1{font-size:clamp(26px,5.6vw,40px);line-height:1.2;margin:0 0 12px;letter-spacing:-.02em}
.hero p{font-size:clamp(16px,2.6vw,19px);color:var(--muted);margin:0 0 6px;max-width:720px}
.crumbs{font-size:14px;color:var(--muted);padding:14px 0 0}
.crumbs a{color:var(--muted)}
.crumbs ol{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:4px}
.crumbs li+li::before{content:"›";margin-right:4px}
h1{font-size:clamp(26px,5.4vw,36px);line-height:1.22;margin:10px 0 10px;letter-spacing:-.02em}
h2{font-size:clamp(21px,4.2vw,26px);line-height:1.3;margin:36px 0 10px;letter-spacing:-.01em}
h3{font-size:18px;margin:22px 0 6px}
p,ul,ol{margin:0 0 14px}
li{margin-bottom:6px}
.lead{font-size:clamp(16.5px,2.6vw,19px);color:var(--muted)}
.meta{font-size:14px;color:var(--muted);margin:0 0 18px}
.grid{display:grid;gap:14px;grid-template-columns:1fr;margin:16px 0 8px}
@media (min-width:640px){.grid{grid-template-columns:1fr 1fr}}
@media (min-width:980px){.grid.three{grid-template-columns:repeat(3,1fr)}}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:18px;box-shadow:var(--shadow)}
a.card{display:block;text-decoration:none;color:var(--ink);transition:transform .15s,border-color .15s}
a.card:hover{border-color:var(--brand);transform:translateY(-2px)}
.card h3{margin:10px 0 6px;font-size:18px}
.card p{margin:0;color:var(--muted);font-size:15.5px}
.ico{width:44px;height:44px;border-radius:12px;background:var(--soft);display:grid;place-items:center;color:var(--brand)}
.ico svg{width:26px;height:26px}
.more{display:inline-block;margin-top:10px;font-weight:600;font-size:15px;color:var(--brand)}
/* calculator */
.calc{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:18px;box-shadow:var(--shadow);margin:18px 0 8px}
.calc h2{margin:0 0 12px;font-size:20px}
.f{margin-bottom:14px}
.f label,.f .lbl,.legend{display:block;font-weight:600;font-size:15px;margin-bottom:6px}
.f small{display:block;color:var(--muted);font-weight:400;margin-top:4px;font-size:13.5px;line-height:1.45}
input[type=text],input[type=number],select{width:100%;min-height:50px;padding:10px 14px;font:inherit;font-size:16px;color:var(--ink);background:var(--bg);border:1.5px solid var(--line);border-radius:12px;-webkit-appearance:none;appearance:none}
select{background-image:linear-gradient(45deg,transparent 50%,var(--muted) 50%),linear-gradient(135deg,var(--muted) 50%,transparent 50%);background-position:calc(100% - 22px) 22px,calc(100% - 16px) 22px;background-size:6px 6px;background-repeat:no-repeat;padding-right:38px}
input:focus,select:focus{border-color:var(--brand);outline:none;box-shadow:0 0 0 3px color-mix(in srgb,var(--brand) 25%,transparent)}
.two{display:grid;gap:12px;grid-template-columns:1fr 1fr}
@media (max-width:380px){.two{grid-template-columns:1fr}}
fieldset{border:0;padding:0;margin:0 0 14px;min-width:0}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chips label{margin:0;font-weight:500;position:relative}
.chips input{position:absolute;opacity:0;inset:0;width:100%;height:100%;margin:0;cursor:pointer}
.chips span{display:inline-flex;align-items:center;min-height:46px;padding:0 16px;border:1.5px solid var(--line);border-radius:999px;background:var(--bg);font-size:15px;line-height:1.3}
.chips input:checked+span{background:var(--brand);border-color:var(--brand);color:var(--brand-ink);font-weight:600}
.chips input:focus-visible+span{outline:3px solid var(--accent);outline-offset:2px}
.btn{display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:0 18px;border-radius:12px;border:1.5px solid var(--brand);background:transparent;color:var(--brand);font:inherit;font-weight:600;font-size:15px;cursor:pointer}
.btn:disabled{opacity:.45;cursor:default}
.res{margin-top:16px;border-top:1px dashed var(--line);padding-top:14px}
.res h3{margin:0 0 8px;font-size:16px;color:var(--muted);font-weight:600;text-transform:none}
#out .r{display:flex;justify-content:space-between;align-items:baseline;gap:14px;padding:9px 0;border-bottom:1px solid var(--line)}
#out .r span{color:var(--muted);min-width:0}
#out .r b{font-variant-numeric:tabular-nums;text-align:right;white-space:nowrap}
#out .r.tot{font-size:18px;border-bottom:0;background:var(--soft);margin:6px -10px;padding:12px 10px;border-radius:10px}
#out .r.tot span{color:var(--ink);font-weight:600}
#out .r.tot b{color:var(--brand);font-size:20px}
#out .r.bad b{color:var(--bad);white-space:normal;font-weight:600}
#out small{font-weight:400;color:var(--muted)}
#out .n{font-size:14.5px;color:var(--muted);margin:12px 0 0;line-height:1.55}
#out .n.warn{background:var(--warn-bg);color:var(--warn);padding:10px 12px;border-radius:10px}
.tbl{overflow-x:auto;-webkit-overflow-scrolling:touch;margin:0 0 14px;border:1px solid var(--line);border-radius:12px;background:var(--card)}
.tbl table{border-collapse:collapse;width:100%;min-width:420px;font-size:15px}
.tbl th,.tbl td{padding:10px 12px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
.tbl th{background:var(--soft);font-size:13.5px;text-transform:none;white-space:nowrap}
.tbl tr:last-child td{border-bottom:0}
.tbl td:nth-child(n+2){white-space:nowrap}
.tbl tr.best td{background:color-mix(in srgb,var(--ok) 10%,transparent)}
.tag{display:inline-block;font-size:12px;font-weight:700;background:var(--ok);color:#fff;border-radius:999px;padding:1px 8px;margin-left:6px}
@media (prefers-color-scheme:dark){.tag{color:#04251a}}
.callout{border-left:4px solid var(--accent);background:var(--card);border-radius:0 12px 12px 0;padding:12px 16px;margin:0 0 16px;border-top:1px solid var(--line);border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
.callout p:last-child{margin:0}
.callout strong:first-child{display:block;margin-bottom:2px}
.article{max-width:760px}
.article ul,.article ol{padding-left:22px}
.faq h3{margin:18px 0 4px}
.related{margin-top:34px;border-top:1px solid var(--line);padding-top:6px}
.checked{font-size:14px;color:var(--muted);margin-top:26px}
.src li{font-size:15px}
/* footer */
.ftr{margin-top:48px;background:var(--card);border-top:1px solid var(--line);padding:28px 0 36px;font-size:14.5px;color:var(--muted)}
.ftr nav{display:flex;flex-wrap:wrap;gap:0 6px;margin-bottom:12px}
.ftr nav a,.ftr button.lnk{display:inline-flex;align-items:center;min-height:44px;padding:0 8px;color:var(--ink);text-decoration:none;background:none;border:0;font:inherit;cursor:pointer}
.ftr nav a:hover,.ftr button.lnk:hover{text-decoration:underline}
.ftr p{margin:0 0 8px;max-width:760px}
.noscript-note{display:none}
@media print{.hdr,.ftr,.nav,.lang,.menu-btn{display:none}.card,.calc{box-shadow:none}}

.fl{width:22px;height:15px;border-radius:2px;box-shadow:0 0 0 1px rgba(0,0,0,.18);flex:none}
.lang li a{gap:10px}