:root{--black:#09090B;--s1:#111113;--s2:#18181B;--s3:#222226;--b1:#2A2A30;--b2:#3A3A42;--white:#F4F4F5;--muted:#71717A;--muted2:#52525B;--concrete:#A1A1AA;--amber:#F59E0B;--amber-d:#D97706;--amber-g:rgba(245,158,11,0.12);--amber-glow:rgba(245,158,11,0.25);--steel:#38BDF8;--steel-d:#0284C7;--steel-g:rgba(56,189,248,0.1);--green:#22C55E;--danger:#EF4444;--r:8px;--rl:14px;--rx:20px;--tr:0.25s cubic-bezier(0.4,0,0.2,1);--tr-slow:0.4s cubic-bezier(0.16,1,0.3,1)}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;-webkit-tap-highlight-color:transparent}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%;overflow-x:hidden}
body{background:var(--black);color:var(--white);font-family:'Inter',sans-serif;font-weight:300;line-height:1.6;min-height:100vh;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a,button{touch-action:manipulation}
a{color:var(--steel);text-decoration:none}
button{font-family:inherit}
.container{max-width:1120px;margin:0 auto;padding:0 24px}
h1,h2,h3{font-family:'Syne',sans-serif;font-weight:800;letter-spacing:-0.02em;color:var(--white)}
::-webkit-scrollbar{width:8px}
::-webkit-scrollbar-track{background:var(--black)}
::-webkit-scrollbar-thumb{background:var(--b2);border-radius:4px}
::-webkit-scrollbar-thumb:hover{background:var(--muted2)}
::selection{background:rgba(245,158,11,0.3);color:var(--white)}

/* NAV (shared with the rest of Estima) */
.nav{position:fixed;top:0;left:0;right:0;z-index:200;height:64px;display:flex;align-items:center;justify-content:space-between;padding:0 28px;padding-left:max(28px,env(safe-area-inset-left));padding-right:max(28px,env(safe-area-inset-right));border-bottom:1px solid rgba(42,42,48,0.6);transition:border-color var(--tr),box-shadow var(--tr)}
.nav::before{content:'';position:absolute;inset:0;z-index:-1;background:rgba(9,9,11,0.75);backdrop-filter:blur(24px) saturate(1.2);transition:background var(--tr)}
.nav-scrolled{border-bottom-color:var(--b1);box-shadow:0 4px 30px rgba(0,0,0,0.3)}
.nav-scrolled::before{background:rgba(9,9,11,0.92)}
.nav-logo{display:flex;align-items:center;gap:9px;text-decoration:none;transition:transform var(--tr)}
.nav-logo:hover{transform:scale(1.02)}
.nav-brand{font-family:'Syne',sans-serif;font-weight:800;font-size:1.05rem;color:var(--white)}
.nav-brand span{color:var(--amber)}
.nav-links{display:flex;align-items:center;gap:24px}
.nav-links a{font-size:0.82rem;color:var(--muted);font-weight:500;transition:color var(--tr);position:relative}
.nav-links a::after{content:'';position:absolute;bottom:-4px;left:0;width:0;height:1.5px;background:var(--amber);transition:width var(--tr);border-radius:2px}
.nav-links a:hover{color:var(--white)}
.nav-links a:hover::after{width:100%}
.nav-links a.current{color:var(--amber)}
.nav-links a.current::after{width:100%}
.nav-actions{display:flex;align-items:center;gap:14px}
.nav-cta{background:var(--amber);color:var(--black)!important;font-weight:700;font-size:0.82rem;padding:10px 20px;border-radius:var(--r);transition:all var(--tr);border:1px solid transparent;position:relative;overflow:hidden}
.nav-cta:hover{transform:translateY(-1px);box-shadow:0 4px 20px rgba(245,158,11,0.3)}
.nav-os{font-size:0.8rem;color:var(--amber)!important;font-weight:600;display:flex;align-items:center;gap:4px;transition:gap var(--tr)}
.nav-os:hover{gap:8px}
.mobile-toggle{display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:8px;z-index:210}
.mobile-toggle span{display:block;width:22px;height:2px;background:var(--white);border-radius:2px;transition:all var(--tr)}
.mobile-toggle.active span:nth-child(1){transform:rotate(45deg) translate(5px,5px)}
.mobile-toggle.active span:nth-child(2){opacity:0}
.mobile-toggle.active span:nth-child(3){transform:rotate(-45deg) translate(5px,-5px)}
@media(max-width:900px){
  .nav-links{position:fixed;top:64px;left:0;right:0;bottom:0;background:rgba(9,9,11,0.97);backdrop-filter:blur(20px);flex-direction:column;align-items:center;justify-content:center;gap:28px;transform:translateY(-100%);opacity:0;pointer-events:none;transition:all var(--tr-slow);z-index:199}
  .nav-links.open{transform:translateY(0);opacity:1;pointer-events:all}
  .nav-links a{font-size:1.1rem}
  .mobile-toggle{display:flex}
}
@media(max-width:480px){
  .nav{padding:0 16px}
  .nav-actions{gap:10px}
  .nav-cta{padding:9px 14px;font-size:0.78rem}
}
html.menu-open,body.menu-open{overflow:hidden;height:100%}
a:focus-visible,button:focus-visible,summary:focus-visible{outline:2px solid var(--amber);outline-offset:2px;border-radius:4px}

/* TOOLS PAGE INTRO */
.tools-intro{padding:120px 24px 36px;text-align:center;position:relative}
.tools-intro::before{content:'';position:absolute;top:-160px;left:50%;transform:translateX(-50%);width:900px;height:420px;background:radial-gradient(ellipse 55% 60% at 45% 40%, rgba(245,158,11,0.12) 0%, transparent 68%);pointer-events:none}
.tools-eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:0.75rem;font-weight:600;letter-spacing:0.08em;text-transform:uppercase;color:var(--amber);background:var(--amber-g);border:1px solid rgba(245,158,11,0.3);padding:8px 18px;border-radius:999px;margin-bottom:22px;position:relative}
.tools-intro h1{font-size:clamp(2.2rem,5.5vw,3.4rem);line-height:1.05;margin-bottom:14px;position:relative}
.tools-intro h1 span{color:var(--amber)}
.tools-intro p{max-width:620px;margin:0 auto;color:var(--muted);font-size:1rem;line-height:1.7;position:relative}
.tools-crumb{max-width:620px;margin:18px auto 0;font-size:0.82rem;color:var(--muted2);position:relative}
.tools-crumb a{color:var(--steel);font-weight:500}

/* APP SHELL (topbar + sidebar + panel) */
.topbar{border-bottom:1px solid var(--b1);background:var(--s1);padding:14px 20px;display:flex;flex-wrap:wrap;gap:14px 24px;align-items:center;position:sticky;top:64px;z-index:10}
.tb-label{font-size:11px;text-transform:uppercase;letter-spacing:0.08em;color:var(--muted);font-weight:600}
.ctrl-group{display:flex;align-items:center;gap:8px}
select{background:var(--s2);color:var(--white);border:1px solid var(--b1);border-radius:6px;padding:7px 10px;font-family:'Inter',sans-serif;font-size:13.5px;cursor:pointer}
select:focus,button:focus-visible,input:focus-visible{outline:2px solid var(--amber);outline-offset:1px}
.unit-toggle{display:flex;border:1px solid var(--b1);border-radius:6px;overflow:hidden}
.unit-toggle button{background:var(--s2);color:var(--muted);border:none;padding:6px 13px;font-family:'IBM Plex Mono',monospace;font-size:12px;font-weight:600;cursor:pointer;letter-spacing:0.03em}
.unit-toggle button.active{background:var(--steel);color:#06222E}
.unit-note{font-size:11.5px;color:var(--muted2);font-style:italic}

.layout{display:flex;max-width:1200px;margin:0 auto;min-height:calc(100vh - 260px)}
nav.sidebar{width:250px;flex-shrink:0;border-right:1px solid var(--b1);padding:20px 12px;overflow-y:auto}
nav.sidebar .cat-heading{font-size:10.5px;text-transform:uppercase;letter-spacing:0.09em;color:var(--steel);padding:16px 10px 8px;font-weight:700}
nav.sidebar .cat-heading:first-child{padding-top:4px}
nav.sidebar button.navitem{display:block;width:100%;text-align:left;background:none;border:none;color:var(--muted);padding:9px 10px;border-radius:7px;cursor:pointer;font-family:'Inter',sans-serif;font-size:13.8px;margin-bottom:1px}
nav.sidebar button.navitem:hover{background:var(--s1);color:var(--white)}
nav.sidebar button.navitem.active{background:var(--s2);color:var(--amber);font-weight:600;border-left:2px solid var(--amber);padding-left:8px}

main{flex:1;padding:32px 36px 60px;min-width:0}
.calc-title{font-family:'Syne',sans-serif;font-size:26px;font-weight:800;margin:0 0 4px}
.calc-sub{color:var(--muted);font-size:14px;margin:0 0 28px;max-width:64ch;line-height:1.6}

.grid{display:grid;grid-template-columns:1fr 1fr;gap:16px 20px;margin-bottom:22px}
.grid.cols-3{grid-template-columns:1fr 1fr 1fr}
@media(max-width:640px){.grid,.grid.cols-3{grid-template-columns:1fr}}
.field label{display:block;font-size:12.5px;color:var(--muted);margin-bottom:6px;font-weight:500}
.field input,.field select.field-select{width:100%;background:var(--s1);border:1px solid var(--b1);color:var(--white);padding:10px 12px;border-radius:8px;font-family:'IBM Plex Mono',monospace;font-size:15px}
.checkbox-field{display:flex;align-items:center;gap:8px;padding-top:8px}
.checkbox-field input{width:auto}
.checkbox-field label{margin:0;font-size:13.5px;color:var(--white)}

.readout{background:var(--s1);border:1px solid var(--b1);border-radius:var(--rl);padding:22px 24px;margin-top:6px;position:relative;overflow:hidden}
.readout::before{content:'';position:absolute;left:0;top:0;bottom:0;width:3px;background:linear-gradient(180deg,var(--amber-d),var(--amber))}
.readout-label{font-size:11px;text-transform:uppercase;letter-spacing:0.08em;color:var(--muted);margin-bottom:8px;font-weight:700}
.readout-value{font-family:'IBM Plex Mono',monospace;font-size:38px;font-weight:600;color:var(--amber);line-height:1;display:flex;align-items:baseline;gap:8px;flex-wrap:wrap}
.readout-value .unit{font-size:16px;color:var(--muted);font-weight:500}
.readout-sub{margin-top:12px;font-size:13px;color:var(--muted);line-height:1.6}
.readout-sub strong{color:var(--white)}
.status-pill{display:inline-flex;align-items:center;gap:6px;font-size:12px;font-weight:600;padding:4px 10px;border-radius:20px;margin-top:12px}
.status-pill.ok{background:rgba(34,197,94,0.12);color:var(--green)}
.status-pill.warn{background:rgba(239,68,68,0.12);color:var(--danger)}

.note-box{border:1px dashed var(--b1);border-radius:8px;padding:12px 14px;margin-top:18px;font-size:12.5px;color:var(--muted);line-height:1.6}
.note-box strong{color:var(--white)}

table.ref-table{width:100%;border-collapse:collapse;margin-top:10px;font-size:13px}
table.ref-table th,table.ref-table td{text-align:left;padding:7px 10px;border-bottom:1px solid var(--b1);font-family:'IBM Plex Mono',monospace}
table.ref-table th{color:var(--muted);font-family:'Inter',sans-serif;font-weight:700;font-size:11.5px;text-transform:uppercase;letter-spacing:0.05em}

@media(max-width:900px){
  .layout{flex-direction:column}
  nav.sidebar{width:100%;border-right:none;border-bottom:1px solid var(--b1);display:flex;flex-wrap:wrap;gap:2px;padding:14px 16px}
  nav.sidebar .cat-heading{width:100%;padding:10px 4px 2px}
  nav.sidebar button.navitem{width:auto;padding:7px 12px;border-radius:999px;border:1px solid var(--b1)}
  nav.sidebar button.navitem.active{border-color:var(--amber);padding-left:12px}
  main{padding:26px 20px 48px}
  .topbar{top:64px}
}
@media(max-width:480px){
  .tools-intro{padding:104px 20px 28px}
  .readout-value{font-size:30px}
}

/* FOOTER (shared with the rest of Estima) */
footer{border-top:1px solid var(--b1);padding:52px 24px 36px;position:relative}
footer::before{content:'';position:absolute;top:0;left:50%;transform:translateX(-50%);width:200px;height:1px;background:linear-gradient(90deg,transparent,var(--amber),transparent)}
.footer-inner{max-width:1120px;margin:0 auto;display:flex;flex-direction:column;gap:28px}
.footer-top{display:flex;justify-content:space-between;flex-wrap:wrap;gap:24px;align-items:center}
.footer-brand{display:flex;align-items:center;gap:10px;transition:transform var(--tr)}
.footer-brand:hover{transform:scale(1.02)}
footer nav{display:flex;gap:20px;flex-wrap:wrap}
footer nav a{font-size:0.8rem;color:var(--muted2);transition:all var(--tr);position:relative}
footer nav a::after{content:'';position:absolute;bottom:-2px;left:0;width:0;height:1px;background:var(--amber);transition:width var(--tr)}
footer nav a:hover{color:var(--white)}
footer nav a:hover::after{width:100%}
.footer-bottom{font-size:0.78rem;color:var(--muted2);padding-top:20px;border-top:1px solid var(--b1)}
@media(max-width:768px){.footer-top{flex-direction:column;align-items:flex-start;gap:22px}footer nav{gap:12px 18px}footer{padding:44px 20px 30px}}

/* BACK TO TOP */
.back-to-top{position:fixed;bottom:calc(24px + env(safe-area-inset-bottom));right:calc(24px + env(safe-area-inset-right));width:44px;height:44px;border-radius:50%;background:var(--s2);border:1px solid var(--b1);color:var(--white);display:flex;align-items:center;justify-content:center;cursor:pointer;opacity:0;transform:translateY(20px);transition:all var(--tr);z-index:100;box-shadow:0 4px 20px rgba(0,0,0,0.3)}
.back-to-top.visible{opacity:1;transform:translateY(0)}
.back-to-top:hover{background:var(--amber);color:var(--black);border-color:var(--amber);transform:translateY(-2px)}

@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:0.01ms!important;animation-iteration-count:1!important;transition-duration:0.01ms!important}
}
</style>

/* ============================================================
   STANDALONE CALCULATOR PAGE — SEO content & breadcrumb
   ============================================================ */
.crumb-bar{max-width:1120px;margin:0 auto;padding:96px 24px 8px;font-size:0.8rem;color:var(--muted2)}
.crumb-bar a{color:var(--steel)}
.crumb-bar span{margin:0 6px;color:var(--muted2)}
.tool-hero{max-width:1120px;margin:0 auto;padding:28px 24px 12px;position:relative;z-index:5}
.tool-hero h1{font-size:clamp(1.7rem,4vw,2.3rem);margin-bottom:10px}
.tool-hero p{color:var(--muted);max-width:70ch;font-size:0.98rem;line-height:1.7}
.related-strip{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.related-strip a{font-size:0.78rem;color:var(--muted);background:var(--s1);border:1px solid var(--b1);padding:6px 12px;border-radius:999px;transition:all var(--tr)}
.related-strip a:hover{color:var(--white);border-color:var(--amber)}

.article{max-width:1120px;margin:0 auto;padding:56px 24px 20px}
.article-inner{max-width:760px}
.article h2{font-size:1.5rem;margin:36px 0 14px}
.article h2:first-child{margin-top:0}
.article h3{font-size:1.1rem;margin:24px 0 10px;color:var(--white);font-family:'Syne',sans-serif;font-weight:700}
.article p{color:var(--concrete);font-size:0.96rem;line-height:1.8;margin-bottom:14px}
.article ul,.article ol{color:var(--concrete);font-size:0.96rem;line-height:1.8;margin:0 0 14px 22px}
.article li{margin-bottom:6px}
.article strong{color:var(--white)}
.article code{font-family:'IBM Plex Mono',monospace;background:var(--s2);border:1px solid var(--b1);padding:2px 7px;border-radius:5px;font-size:0.88em;color:var(--amber)}
.formula-box{background:var(--s1);border:1px solid var(--b1);border-left:3px solid var(--amber);border-radius:var(--r);padding:16px 20px;margin:16px 0;font-family:'IBM Plex Mono',monospace;font-size:1rem;color:var(--white);overflow-x:auto}

.faq{margin-top:8px}
.faq details{border:1px solid var(--b1);border-radius:var(--r);margin-bottom:10px;background:var(--s1);overflow:hidden}
.faq summary{padding:14px 18px;cursor:pointer;font-weight:600;font-size:0.94rem;color:var(--white);list-style:none;display:flex;justify-content:space-between;align-items:center;gap:12px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:'+';color:var(--amber);font-size:1.2rem;flex-shrink:0}
.faq details[open] summary::after{content:'−'}
.faq details p{padding:0 18px 16px;margin:0;color:var(--muted);font-size:0.92rem;line-height:1.7}

.more-tools{max-width:1120px;margin:0 auto;padding:8px 24px 60px}
.more-tools h2{font-size:1.3rem;margin-bottom:18px}
.more-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:12px}
.more-grid a{display:block;background:var(--s1);border:1px solid var(--b1);border-radius:var(--r);padding:14px 16px;font-size:0.86rem;color:var(--white);font-weight:500;transition:all var(--tr)}
.more-grid a:hover{border-color:var(--amber);transform:translateY(-2px)}
.more-grid a span{display:block;color:var(--muted);font-weight:400;font-size:0.78rem;margin-top:4px}

@media(max-width:640px){
  .crumb-bar{padding-top:96px}
  .article,.tool-hero,.crumb-bar,.more-tools{padding-left:20px;padding-right:20px}
}