:root{
  box-sizing:border-box;padding-top:env(safe-area-inset-top,0px);padding-bottom:env(safe-area-inset-bottom,0px);
  --ink:#10243B;--muted:#56677A;--bg:#F1F5F9;--card:#FFFFFF;--line:#D6DFE8;
  --blue:#1D4E89;--blue-soft:#E2ECF8;--orange:#D9560F;--green:#1B7657;--red:#B23A2E;--warn-bg:#FFF1E6;
  --display:ui-rounded,'SF Pro Rounded','Segoe UI Variable Display','Trebuchet MS',system-ui,sans-serif;
  --body:system-ui,-apple-system,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){--ink:#E8EEF5;--muted:#9BAABD;--bg:#0B1522;--card:#132238;--line:#263950;--blue:#78ABEF;--blue-soft:#1B3453;--orange:#F28C52;--green:#55C7A0;--red:#F0796D;--warn-bg:#3A2616}
}
:root[data-theme="dark"]{--ink:#E8EEF5;--muted:#9BAABD;--bg:#0B1522;--card:#132238;--line:#263950;--blue:#78ABEF;--blue-soft:#1B3453;--orange:#F28C52;--green:#55C7A0;--red:#F0796D;--warn-bg:#3A2616}
html{scroll-padding-top:env(safe-area-inset-top,0px);height:100%}
*,*::before,*::after{box-sizing:inherit}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--body);font-size:16px;line-height:1.5;min-height:100%}
[hidden]{display:none!important}
.wrap{max-width:1140px;margin:0 auto;padding:32px 20px 64px}
.intro h1{font-family:var(--display);font-weight:700;font-size:clamp(30px,5vw,48px);line-height:1.05;margin:0 0 10px;letter-spacing:-.02em}
.intro p{margin:0;color:var(--muted);max-width:62ch}
h2{font-family:var(--display);font-size:22px;font-weight:700;margin:0 0 12px;letter-spacing:-.01em}
h3{font-family:var(--display);font-size:17px;margin:18px 0 8px}
.chooser{display:grid;grid-template-columns:repeat(2,1fr);gap:14px;margin:26px 0 28px}
.choice{all:unset;box-sizing:border-box;cursor:pointer;background:var(--card);border:2px solid var(--line);border-radius:14px;padding:18px;display:flex;flex-direction:column;gap:6px;transition:border-color .15s,background .15s}
.choice:hover{border-color:var(--blue)}
.choice[aria-pressed="true"]{border-color:var(--blue);background:var(--blue-soft)}
.choice:focus-visible,.seg button:focus-visible,summary:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--blue);outline-offset:2px}
.choice svg{width:38px;height:38px;color:var(--blue)}
.choice b{font-family:var(--display);font-size:20px}
.choice span{color:var(--muted);font-size:14.5px}
.workspace{display:grid;grid-template-columns:minmax(0,1fr) 410px;gap:24px;align-items:start}
.inputs>.step,.inputs>details{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px;margin-bottom:16px}
details.step>summary{cursor:pointer;font-family:var(--display);font-weight:700;font-size:19px;list-style:none;display:flex;gap:12px;align-items:center}
details.step>summary::-webkit-details-marker{display:none}
details.step>summary::after{content:"+";font-size:24px;color:var(--blue);line-height:1}
details.step[open]>summary::after{content:"−"}
details.step[open]>summary{margin-bottom:14px}
summary .live{font-family:var(--body);font-weight:500;font-size:14px;color:var(--muted);margin-left:auto}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:16px 18px}
.fld label{display:block;font-weight:600;font-size:14.5px;margin-bottom:4px}
.inp{display:flex;align-items:center;border:1px solid var(--line);border-radius:10px;background:var(--bg);padding:0 12px}
.inp input{all:unset;flex:1;min-width:0;padding:9px 0;font-size:17px;font-variant-numeric:tabular-nums;font-weight:600}
.inp .u{color:var(--muted);font-size:14px;margin-left:8px}
.fld input[type=range]{width:100%;margin:8px 0 0;accent-color:var(--blue)}
.fld small{display:block;color:var(--muted);font-size:13px;margin-top:2px}
select{width:100%;padding:9px 10px;border-radius:10px;border:1px solid var(--line);background:var(--bg);color:var(--ink);font:inherit;font-weight:600}
.seg{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:10px}
.seg button{all:unset;box-sizing:border-box;cursor:pointer;border:2px solid var(--line);border-radius:12px;padding:12px 14px;background:var(--bg);display:flex;flex-direction:column;gap:2px}
.seg button b{font-family:var(--display);font-size:17px}
.seg button span{font-size:13.5px;color:var(--muted)}
.seg button[aria-pressed="true"]{border-color:var(--blue);background:var(--blue-soft)}
.explain{background:var(--blue-soft);border-radius:10px;padding:10px 14px;font-size:14.5px;margin:12px 0 0}
.chk{display:flex;gap:10px;align-items:flex-start;margin-top:14px;font-size:15px}
.chk input{margin-top:4px;accent-color:var(--blue);width:18px;height:18px}
.meter{margin-top:14px;font-size:14px;color:var(--muted)}
.meter progress{display:block;width:100%;height:8px;margin-top:5px;appearance:none;-webkit-appearance:none;border:0;border-radius:5px;background:var(--line);overflow:hidden}
.meter progress::-webkit-progress-bar{background:var(--line)}
.meter progress::-webkit-progress-value{background:var(--blue);border-radius:5px}
.meter progress::-moz-progress-bar{background:var(--blue);border-radius:5px}
.mt14{margin-top:14px}.mt16{margin-top:16px}.explain.tight{margin-top:10px}
.skip{position:absolute;left:-999px;top:0;background:var(--blue);color:#fff;padding:8px 14px;border-radius:0 0 8px 0;z-index:10}
.skip:focus{left:0}
noscript p{background:var(--warn-bg);border-left:4px solid var(--orange);padding:12px 16px;border-radius:8px;margin:16px 0}
@media print{.site-header,.site-footer,.chooser,.inputs,.skip{display:none!important}.workspace{display:block}.res{position:static;max-height:none;border:0}}
.res{position:sticky;top:12px;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px;max-height:calc(100vh - 24px);overflow:auto}
.res .empty{color:var(--muted)}
.hero .lab{color:var(--muted);font-size:14.5px}
.hero strong{display:block;font-family:var(--display);font-size:46px;line-height:1.05;letter-spacing:-.02em;font-variant-numeric:tabular-nums}
.hero .sub{display:block;color:var(--green);font-weight:600;margin-top:2px}
.hero .sub.neg{color:var(--red)}
.kv{display:flex;justify-content:space-between;gap:12px;padding:8px 0;border-bottom:1px solid var(--line);font-size:15px}
.kv:last-child{border-bottom:0}
.kv span:first-child{color:var(--muted)}
.kv b{font-variant-numeric:tabular-nums;text-align:right;white-space:nowrap}
.kv.pos b{color:var(--green)}.kv.neg b{color:var(--red)}
.res h4{font-family:var(--display);font-size:16px;margin:20px 0 4px}
.warn{background:var(--warn-bg);border-left:4px solid var(--orange);border-radius:8px;padding:10px 14px;margin:14px 0 0;font-size:14px}
.warn p{margin:4px 0}
.legend{display:flex;gap:16px;font-size:13px;color:var(--muted);margin:14px 0 2px}
.legend i{display:inline-block;width:11px;height:11px;border-radius:3px;margin-right:6px;vertical-align:-1px}
svg.chart{width:100%;height:auto;display:block}
svg.chart text{fill:var(--muted);font-size:11px;font-family:var(--body)}
.res details{border-top:1px solid var(--line);margin-top:14px;padding-top:10px}
.res summary{cursor:pointer;font-weight:600;color:var(--blue)}
table{width:100%;border-collapse:collapse;font-size:13px;font-variant-numeric:tabular-nums}
.tw{overflow-x:auto;max-width:100%;margin-top:8px}
th,td{padding:5px 8px;text-align:right;border-bottom:1px solid var(--line);white-space:nowrap}
th:first-child,td:first-child{text-align:left}
th{color:var(--muted);font-weight:600}
.cmp th,.cmp td{font-size:13.5px}
.rules{margin-top:26px}
.rules details{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px 18px;margin-bottom:10px}
.rules summary{cursor:pointer;font-family:var(--display);font-weight:700;font-size:17px}
.rules ul{margin:10px 0 0;padding-left:20px}
.rules li{margin:5px 0}
@media (max-width:940px){.workspace{grid-template-columns:1fr}.res{position:static;max-height:none}.chooser{grid-template-columns:1fr}}
@media (max-width:520px){.grid2{grid-template-columns:1fr}.hero strong{font-size:38px}}
@media (prefers-reduced-motion:reduce){*{transition:none!important}}
.dot-int{background:var(--orange)}.dot-prin{background:var(--blue)}
.share{display:flex;flex-wrap:wrap;gap:8px 14px;align-items:center;margin:-8px 0 20px}
.share button{all:unset;cursor:pointer;box-sizing:border-box;padding:7px 14px;border:1px solid var(--blue);border-radius:8px;color:var(--blue);font-weight:600;font-size:14px}
.share button:hover{background:var(--blue-soft)}
.share button:focus-visible{outline:3px solid var(--blue);outline-offset:2px}
.share small{color:var(--muted);font-size:13px}
#copymsg{color:var(--green);font-weight:600;font-size:14px}
@media print{.share{display:none!important}}

/* ---------- site header ---------- */
:root{--foot-bg:#0F2238;--foot-ink:#C8D4E2;--foot-muted:#8FA1B6;--foot-line:#243A55}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){--foot-bg:#07101B;--foot-line:#1C2D42}}
:root[data-theme="dark"]{--foot-bg:#07101B;--foot-line:#1C2D42}
.site-header{background:var(--card);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5}
.bar{max-width:1140px;margin:0 auto;padding:12px 20px;display:flex;align-items:center;gap:22px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none;font-family:var(--display);font-weight:700;font-size:19px;letter-spacing:-.01em;margin-right:auto;min-width:0}
.brand svg{width:34px;height:34px;flex:none}
.brand span{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.site-header nav ul{list-style:none;margin:0;padding:0;display:flex;gap:4px}
.site-header nav a{display:block;padding:8px 11px;border-radius:8px;color:var(--muted);text-decoration:none;font-weight:600;font-size:15px}
.site-header nav a:hover{color:var(--ink);background:var(--bg)}
.site-header nav a[aria-current="page"]{color:var(--blue);background:var(--blue-soft)}
.lang{display:flex;flex:none;border:1px solid var(--line);border-radius:8px;overflow:hidden}
.lang a{padding:6px 10px;font-size:13px;font-weight:700;color:var(--muted);text-decoration:none;letter-spacing:.02em}
.lang a+a{border-left:1px solid var(--line)}
.lang a[aria-current="true"]{background:var(--blue);color:#fff}
.lang a:hover:not([aria-current]){color:var(--ink);background:var(--bg)}
.nav-menu{display:none;position:relative}
.nav-menu summary{list-style:none;cursor:pointer;padding:7px 12px;border:1px solid var(--line);border-radius:8px;font-weight:600;font-size:14px}
.nav-menu summary::-webkit-details-marker{display:none}
.nav-menu[open] summary{background:var(--blue-soft);border-color:var(--blue)}
.nav-menu nav{position:absolute;right:0;top:calc(100% + 8px);background:var(--card);border:1px solid var(--line);border-radius:12px;padding:8px;min-width:220px;box-shadow:0 12px 28px rgba(16,36,59,.16)}
.nav-menu nav ul{flex-direction:column}
.brand:focus-visible,.site-header a:focus-visible,.nav-menu summary:focus-visible,.site-footer a:focus-visible,.btn:focus-visible,.prose a:focus-visible,.notice a:focus-visible{outline:3px solid var(--blue);outline-offset:2px}
@media (max-width:860px){.nav-wide{display:none}.nav-menu{display:block}.bar{gap:10px}}
@media (max-width:420px){.brand{font-size:16px}.brand svg{width:30px;height:30px}}

/* ---------- footer ---------- */
.site-footer{background:var(--foot-bg);color:var(--foot-ink);margin-top:40px;font-size:14.5px}
.foot{max-width:1140px;margin:0 auto;padding:44px 20px 28px;display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:28px}
.foot p{margin:0}
.foot-name{font-family:var(--display);font-weight:700;font-size:18px;color:#fff;margin-bottom:8px!important}
.foot-brand p:last-child{color:var(--foot-muted);max-width:36ch}
.foot-h{font-weight:700;color:#fff;margin-bottom:10px!important}
.foot-col ul{list-style:none;margin:0;padding:0}
.foot-col li{margin:6px 0}
.site-footer a{color:var(--foot-ink);text-decoration:none}
.site-footer a:hover{color:#fff;text-decoration:underline}
.foot-base{max-width:1140px;margin:0 auto;padding:18px 20px 26px;border-top:1px solid var(--foot-line);color:var(--foot-muted);font-size:13px;display:flex;flex-wrap:wrap;justify-content:space-between;gap:6px 24px}
.foot-base p{margin:0}
@media (max-width:760px){.foot{grid-template-columns:1fr 1fr}.foot-brand{grid-column:1/-1}}

/* ---------- calculator page ---------- */
.intro{margin-bottom:4px}
.notice{margin-top:30px;padding:16px 20px;border:1px solid var(--line);border-radius:12px;background:var(--card);color:var(--muted);font-size:14px;max-width:80ch}
.notice p{margin:0}.notice p+p{margin-top:8px}
.notice a,.prose a{color:var(--blue);font-weight:600}

/* ---------- content pages ---------- */
.prose{max-width:760px}
.prose h1{font-family:var(--display);font-weight:700;font-size:clamp(30px,4.6vw,42px);line-height:1.1;letter-spacing:-.02em;margin:8px 0 12px}
.prose h2{margin:34px 0 10px}
.prose p,.prose li{line-height:1.65}
.prose .lead{font-size:18.5px;color:var(--muted);margin:0 0 8px}
.prose ul{padding-left:22px}
.prose li{margin:6px 0}
.small{font-size:14px;color:var(--muted)}
.faq{margin-top:22px}
.faq details{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px 18px;margin-bottom:10px}
.faq summary{cursor:pointer;font-weight:700;font-size:16.5px}
.faq details[open] summary{margin-bottom:6px}
.faq details:target{border-color:var(--blue)}
.btn{display:inline-block;cursor:pointer;border:0;border-radius:10px;background:var(--blue);color:#fff!important;padding:11px 20px;font:inherit;font-weight:700;text-decoration:none}
.btn:hover{filter:brightness(1.08)}
.contact-form{margin:22px 0;padding:22px;background:var(--card);border:1px solid var(--line);border-radius:14px;display:grid;gap:16px}
.contact-form input,.contact-form select,.contact-form textarea{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--ink);font:inherit}
.contact-form textarea{resize:vertical;min-height:140px}
.contact-form input:focus-visible,.contact-form textarea:focus-visible,.contact-form select:focus-visible{outline:3px solid var(--blue);outline-offset:1px}
.contact-form .small{margin:0}
.contact-form .btn{justify-self:start}
.hp{position:absolute!important;left:-10000px;width:1px;height:1px;overflow:hidden}
.skip{position:absolute;left:-999px;top:0}
.skip:focus{left:0;z-index:20}
.facts{list-style:none;margin:14px 0 0;padding:0;display:flex;flex-wrap:wrap;gap:8px 22px;color:var(--ink);font-size:14.5px;font-weight:600}
.facts li{display:flex;align-items:center;gap:7px}
.facts li::before{content:"";width:16px;height:16px;flex:none;border-radius:50%;background:var(--green) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath d='M4.5 8.2l2.3 2.3 4.7-4.9' fill='none' stroke='%23fff' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center/100% no-repeat}
@media (max-width:430px){.brand span{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}}