*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:"DM Sans",system-ui,-apple-system,"Segoe UI",sans-serif;color:#111827;background:#fff;line-height:1.6;font-size:16px}
img{max-width:100%;height:auto;display:block}
a{color:#2563eb;text-decoration:none}
a:hover{color:#1d4ed8;text-decoration:underline}
h1,h2,h3{line-height:1.25;margin:0;text-wrap:balance}
p{margin:0 0 1em;text-wrap:pretty}
.wrap{max-width:1200px;margin:0 auto;padding:0 20px}
.skip{position:absolute;left:-999px}.skip:focus{left:12px;top:12px;background:#fff;padding:8px 12px;z-index:10}
/* header */
.site-header{background:#fff;box-shadow:0 1px 3px rgba(0,0,0,.08);position:sticky;top:0;z-index:5}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;min-height:64px;gap:16px}
.brand{display:flex;align-items:center;gap:12px;font-weight:700;font-size:20px;color:#111827}
.brand:hover{text-decoration:none;color:#111827}
.brand img{width:28px;height:28px;border-radius:6px;object-fit:cover}
.nav{display:flex;gap:8px}
.nav a{color:#4b5563;font-size:15px;padding:12px 10px}
.nav a[aria-current="page"]{color:#2563eb}
/* hero */
.hero{background:linear-gradient(160deg,#eef2ff 0%,#fff 45%);text-align:center;padding:72px 0 48px}
.hero img{width:72px;height:72px;margin:0 auto 28px;border-radius:14px;object-fit:cover;box-shadow:0 10px 24px rgba(17,24,39,.12)}
.hero h1{font-size:clamp(36px,6vw,60px);letter-spacing:-.02em}
.hero p{max-width:720px;margin:20px auto 0;color:#6b7280;font-size:19px}
.search{max-width:650px;margin:40px auto 40px;position:relative}
.search input{width:100%;padding:16px 18px 16px 48px;border:1px solid #e5e7eb;border-radius:12px;font:inherit;box-shadow:0 1px 2px rgba(0,0,0,.04)}
.search input:focus{outline:2px solid #bfdbfe;border-color:#2563eb}
.search svg{position:absolute;left:17px;top:50%;transform:translateY(-50%);color:#6b7280}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:24px;padding-bottom:80px}
.card{position:relative;cursor:pointer;border:1px solid #e5e7eb;border-radius:14px;padding:24px;display:flex;flex-direction:column;background:#fff;transition:box-shadow .2s,border-color .2s}
.card a:hover{text-decoration:none}
.card h2 a::after{content:"";position:absolute;inset:0;border-radius:14px}
.card .go{position:relative;z-index:1}
.card:hover{box-shadow:0 8px 24px rgba(17,24,39,.08);border-color:#d1d5db}
.card h2{font-size:21px;display:flex;gap:14px;align-items:flex-start}
.card h2 img{width:26px;height:26px;border-radius:5px;flex:none;margin-top:1px;object-fit:cover}
.card h2 a{color:#111827}
.card p{color:#6b7280;font-size:15px;margin:16px 0 20px;flex:1}
.card .go{border-top:1px solid #e5e7eb;padding-top:16px;font-weight:700;font-size:15px}
.empty{grid-column:1/-1;text-align:center;color:#6b7280}
.intro-copy{max-width:820px;margin:0 auto;padding:0 0 80px;color:#4b5563}
.intro-copy h2{color:#111827;font-size:26px;margin:0 0 14px}
.intro-copy h3{color:#111827;font-size:19px;margin:24px 0 8px}
/* calculator layout */
.page{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:32px;padding:40px 20px 80px;max-width:1040px;margin:0 auto}
.crumbs{font-size:14px;color:#6b7280;margin-bottom:18px}
.crumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:6px;margin:0;padding:0}
.crumbs li+li::before{content:"/";margin-right:6px;color:#9ca3af}
.title{display:flex;align-items:center;gap:16px}
.title img{width:36px;height:36px;border-radius:8px;object-fit:cover}
.title h1{font-size:clamp(28px,4vw,34px);letter-spacing:-.01em}
.lede{color:#6b7280;font-size:17px;margin:14px 0 28px}
.panel{border:1px solid #e5e7eb;border-radius:14px;padding:28px;margin-bottom:24px;background:#fff;box-shadow:0 1px 3px rgba(0,0,0,.04)}
.panel h2{font-size:19px;display:flex;align-items:center;gap:10px;margin-bottom:18px}
.step{width:26px;height:26px;border-radius:50%;background:#eef2ff;color:#2563eb;font-size:13px;font-weight:700;display:inline-flex;align-items:center;justify-content:center;flex:none}
.panel hr{border:0;border-top:1px solid #e5e7eb;margin:26px 0}
.fields{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}
.fields.c3{grid-template-columns:repeat(3,minmax(0,1fr))}
.fields.c2{grid-template-columns:repeat(2,minmax(0,1fr))}
.fields.c5{grid-template-columns:repeat(5,minmax(0,1fr))}
label{display:block;font-size:14px;font-weight:600;margin-bottom:6px}
input,select{width:100%;font:inherit;font-size:16px;padding:10px 12px;border:1px solid #e5e7eb;border-radius:9px;background:#fff;color:#111827;min-height:46px}
input:focus,select:focus{outline:2px solid #bfdbfe;border-color:#2563eb}
.hint{font-size:13px;color:#6b7280;margin-top:4px}
.viz{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.viz-head{display:flex;justify-content:space-between;align-items:center;font-weight:600;font-size:15px;margin-bottom:10px}
.tag{font-size:12px;background:#eef2ff;color:#2563eb;padding:2px 10px;border-radius:99px;font-weight:500}
.tag.gray{background:#f3f4f6;color:#374151}
.viz-box{background:#f9fafb;border:1px solid #e5e7eb;border-radius:10px;aspect-ratio:5/6;display:flex;align-items:center;justify-content:center}
.viz-box svg{width:100%;height:100%}
.result{background:#eef2ff;border:1px solid #bfdbfe;border-radius:14px;padding:28px;text-align:center;margin-bottom:24px}
.result .lbl{color:#2563eb;font-weight:600;letter-spacing:.04em;text-transform:uppercase;font-size:15px}
.result .big{font-size:56px;font-weight:700;line-height:1.1;margin-top:6px}
.result .big small{font-size:22px;font-weight:500;color:#6b7280;margin-left:10px}
.result .cost{margin-top:8px;color:#374151}
.multi{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));margin-top:16px}
.multi>div{padding:6px 12px}
.multi>div+div{border-left:1px solid #bfdbfe}
.multi .k{font-size:12px;color:#2563eb;font-weight:600;text-transform:uppercase;letter-spacing:.04em}
.multi .v{font-size:30px;font-weight:700}
.multi .v small{font-size:15px;color:#6b7280;font-weight:500;margin-left:4px}
.multi .s{font-size:12px;color:#6b7280}
.actions{display:flex;gap:12px;flex-wrap:wrap;padding-bottom:28px;border-bottom:1px solid #e5e7eb;margin-bottom:36px}
.btn{display:inline-flex;align-items:center;gap:8px;font:inherit;font-weight:600;font-size:15px;border:0;border-radius:10px;padding:0 20px;min-height:48px;cursor:pointer}
.btn-2{background:#f3f4f6;color:#111827}.btn-2:hover{background:#e5e7eb}
.btn-1{background:#2563eb;color:#fff}.btn-1:hover{background:#1d4ed8}
.seg{display:inline-flex;background:#f3f4f6;border-radius:10px;padding:4px;gap:4px;margin-bottom:24px}
.seg button{font:inherit;font-size:15px;border:0;background:transparent;padding:10px 22px;border-radius:8px;cursor:pointer;color:#4b5563;min-height:44px}
.seg button[aria-selected="true"]{background:#fff;color:#111827;font-weight:600;box-shadow:0 1px 2px rgba(0,0,0,.08)}
.chips{display:flex;gap:10px;flex-wrap:wrap}
.chips button{font:inherit;font-size:15px;border:1px solid #e5e7eb;background:#fff;border-radius:9px;padding:0 16px;min-height:44px;cursor:pointer}
.chips button[aria-pressed="true"]{background:#2563eb;color:#fff;border-color:#2563eb}
.configs{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.configs button{font:inherit;border:1px solid #e5e7eb;background:#f9fafb;border-radius:10px;padding:14px;cursor:pointer;text-align:center}
.configs button[aria-pressed="true"]{border-color:#93c5fd;background:#eef2ff}
.configs svg{height:110px;width:auto;margin:0 auto 6px;display:block}
/* article */
.content{color:#4b5563}
.content h2{color:#111827;font-size:24px;margin:36px 0 14px}
.content h2:first-child{margin-top:0}
.content h3{color:#111827;font-size:18px;margin:22px 0 8px}
.content strong{color:#111827}
.content ul{padding-left:20px;margin:0 0 1em}
.content li{margin-bottom:6px}
.formula{background:#f3f4f6;border:1px solid #e5e7eb;border-radius:12px;padding:22px}
.formula code{display:block;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:14px;color:#111827;font-weight:600;white-space:pre-wrap;margin-bottom:10px}
.formula p{font-size:15px;margin:10px 0 0}
.example{border:1px solid #e5e7eb;border-radius:12px;padding:22px}
.example .sc{color:#111827}.example .sc b{color:#2563eb;font-weight:600}
.example .final{border-top:1px solid #e5e7eb;padding-top:12px;margin-top:12px}
.proscons{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:16px 0}
.pros,.cons{border-radius:12px;padding:20px;font-size:15px}
.pros{background:#f0fdf4;border:1px solid #bbf7d0}.cons{background:#fef2f2;border:1px solid #fecaca}
.pros h3{color:#15803d;margin:0 0 10px;font-size:16px}.cons h3{color:#b91c1c;margin:0 0 10px;font-size:16px}
.pros ul,.cons ul{margin:0;padding-left:18px}
.faq details{border:1px solid #e5e7eb;border-radius:10px;padding:14px 18px;margin-bottom:10px}
.faq summary{cursor:pointer;font-weight:600;color:#111827}
.faq details p{margin:10px 0 0}
.updated{font-size:14px;color:#6b7280;margin-top:28px}
/* sidebar */
.side{display:flex;flex-direction:column;gap:24px}
.side-photo{border-radius:14px;overflow:hidden;border:1px solid #e5e7eb;aspect-ratio:3/2}
.side-photo img{width:100%;height:100%;object-fit:cover}
.tools{border:1px solid #e5e7eb;border-radius:14px;padding:22px;position:sticky;top:84px}
.tools h2{font-size:17px;padding-bottom:14px;border-bottom:1px solid #e5e7eb;margin-bottom:16px}
.tools ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:8px}
.tools a{display:block;background:#f3f4f6;color:#4b5563;border-radius:9px;padding:10px 14px;font-size:14px}
.tools a:hover{background:#e5e7eb;text-decoration:none;color:#111827}
.tools a[aria-current="page"]{background:#2563eb;color:#fff}
/* simple pages */
.doc{max-width:760px;margin:0 auto;padding:48px 20px 80px;color:#4b5563}
.doc h1{color:#111827;font-size:34px;margin:14px 0 8px}
.doc h2{color:#111827;font-size:21px;margin:34px 0 12px;padding-top:30px;border-top:1px solid #e5e7eb}
.doc h2:first-of-type{border:0;padding-top:0}
.doc strong{color:#111827}
.doc ul{padding-left:20px}.doc li{margin-bottom:8px}
.contact{max-width:620px;margin:0 auto;padding:56px 20px 80px;text-align:center}
.contact h1{font-size:38px;margin:14px 0}
.contact .lede{margin-bottom:36px}
.form{text-align:left;border:1px solid #e5e7eb;border-radius:14px;padding:32px;box-shadow:0 4px 16px rgba(17,24,39,.06);display:grid;gap:20px}
.form textarea{width:100%;font:inherit;font-size:16px;padding:12px;border:1px solid #e5e7eb;border-radius:9px;min-height:170px;resize:vertical}
.form .btn{justify-content:center;width:100%;font-size:18px;min-height:56px}
.form-note{font-size:14px;color:#6b7280;text-align:center}
/* footer */
.site-footer{background:#f3f4f6;border-top:1px solid #e5e7eb;padding:36px 0}
.site-footer .wrap{display:flex;align-items:center;justify-content:space-between;gap:20px;flex-wrap:wrap}
.site-footer .brand{font-size:17px}
.site-footer .brand img{width:22px;height:22px}
.foot-nav{display:flex;gap:4px 18px;flex-wrap:wrap}
.foot-nav a{color:#111827;font-size:15px;padding:8px 0}
.copy{color:#6b7280;font-size:14px;margin:0}
.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);background:#111827;color:#fff;padding:12px 20px;border-radius:10px;font-size:15px;opacity:0;transition:opacity .2s;pointer-events:none}
.toast.show{opacity:1}
@media (max-width:900px){.page{grid-template-columns:1fr}.tools{position:static}.side{order:2}}
@media (max-width:640px){.fields,.fields.c3,.fields.c5{grid-template-columns:repeat(2,minmax(0,1fr))}.viz,.proscons{grid-template-columns:1fr}.multi{grid-template-columns:1fr}.multi>div+div{border-left:0;border-top:1px solid #bfdbfe}.panel{padding:20px}.result .big{font-size:44px}.configs{grid-template-columns:repeat(3,minmax(0,1fr))}.site-footer .wrap{flex-direction:column;align-items:flex-start}.fields.c2{grid-template-columns:1fr}}