/* =========================================================
   PercentBase — original stylesheet
   Author: built for percentbase.com
   Sections: 1 Tokens  2 Base  3 Header  4 Hero  5 Calculator
             6 Cards  7 Content  8 Ads  9 Footer  10 Utilities
   ========================================================= */

/* ---------- 1. DESIGN TOKENS ---------- */
:root{
  --indigo-50:#eef2ff;
  --indigo-100:#e0e7ff;
  --indigo-500:#6366f1;
  --indigo-600:#4f46e5;
  --indigo-700:#4338ca;
  --teal-50:#ecfdf5;
  --teal-400:#2dd4bf;
  --teal-500:#14b8a6;
  --teal-600:#0d9488;
  --amber-500:#f59e0b;
  --rose-500:#f43f5e;

  --bg:#f6f7fb;
  --bg-soft:#eef1f8;
  --surface:#ffffff;
  --surface-2:#f8fafc;
  --border:#e4e8f0;
  --border-strong:#cfd6e4;
  --text:#101828;
  --text-soft:#475467;
  --text-mute:#667085;

  --brand:var(--indigo-600);
  --brand-strong:var(--indigo-700);
  --accent:var(--teal-600);

  --radius-sm:10px;
  --radius:14px;
  --radius-lg:20px;
  --radius-xl:28px;

  --shadow-sm:0 1px 2px rgba(16,24,40,.06);
  --shadow:0 6px 18px -6px rgba(16,24,40,.12), 0 2px 6px -2px rgba(16,24,40,.06);
  --shadow-lg:0 24px 48px -20px rgba(49,46,129,.28);

  --maxw:1140px;
  --font:"Plus Jakarta Sans","Segoe UI",Roboto,-apple-system,BlinkMacSystemFont,Helvetica,Arial,sans-serif;
  --mono:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;
}

[data-theme="dark"]{
  --bg:#0b1020;
  --bg-soft:#0f1629;
  --surface:#121a2e;
  --surface-2:#182135;
  --border:#25304a;
  --border-strong:#33405e;
  --text:#eef2f8;
  --text-soft:#b9c2d6;
  --text-mute:#8e9bb5;
  --brand:#8b8cf9;
  --brand-strong:#a5a6fb;
  --accent:#2dd4bf;
  --shadow:0 6px 18px -6px rgba(0,0,0,.5);
  --shadow-lg:0 24px 48px -20px rgba(0,0,0,.65);
}

/* ---------- 2. BASE ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  font-family:var(--font);
  font-size:16px;
  line-height:1.65;
  color:var(--text);
  background:var(--bg);
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img,svg{max-width:100%;height:auto;display:block}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{line-height:1.25;margin:0 0 .5em;font-weight:800;letter-spacing:-.02em}
h1{font-size:clamp(1.8rem,5.2vw,2.75rem)}
h2{font-size:clamp(1.35rem,3.6vw,1.9rem);margin-top:0}
h3{font-size:clamp(1.1rem,2.8vw,1.3rem)}
p{margin:0 0 1rem}
ul,ol{margin:0 0 1rem;padding-left:1.25rem}
li{margin-bottom:.4rem}
small{font-size:.85rem}
.container{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:16px}
section{scroll-margin-top:80px}
:focus-visible{outline:3px solid var(--indigo-500);outline-offset:2px;border-radius:6px}
.skip-link{position:absolute;left:-9999px;top:0;background:var(--brand);color:#fff;padding:10px 16px;z-index:200;border-radius:0 0 10px 0}
.skip-link:focus{left:0}

/* ---------- 3. HEADER / NAV ---------- */
.site-header{
  position:sticky;top:0;z-index:100;
  background:color-mix(in srgb,var(--surface) 88%,transparent);
  backdrop-filter:saturate(1.6) blur(12px);
  border-bottom:1px solid var(--border);
}
.header-inner{display:flex;align-items:center;gap:12px;height:64px}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.12rem;color:var(--text);letter-spacing:-.03em}
.logo:hover{text-decoration:none}
.logo-mark{
  width:34px;height:34px;flex:0 0 34px;border-radius:11px;
  background:linear-gradient(135deg,var(--indigo-600),var(--teal-500));
  display:grid;place-items:center;color:#fff;font-size:.95rem;font-weight:800;
  box-shadow:0 6px 14px -6px rgba(79,70,229,.8);
}
.logo span b{color:var(--brand)}
.nav{margin-left:auto;display:flex;align-items:center;gap:4px}
.nav-links{display:flex;align-items:center;gap:2px;list-style:none;margin:0;padding:0}
.nav-links a{
  display:block;padding:9px 12px;border-radius:10px;font-size:.93rem;
  font-weight:600;color:var(--text-soft);
}
.nav-links a:hover{background:var(--bg-soft);color:var(--brand);text-decoration:none}
.nav-links a[aria-current="page"]{color:var(--brand);background:var(--indigo-50)}
[data-theme="dark"] .nav-links a[aria-current="page"]{background:rgba(99,102,241,.16)}

.dropdown{position:relative}
.dropdown>button{
  display:flex;align-items:center;gap:6px;background:none;border:0;cursor:pointer;
  font:inherit;font-size:.93rem;font-weight:600;color:var(--text-soft);
  padding:9px 12px;border-radius:10px;
}
.dropdown>button:hover{background:var(--bg-soft);color:var(--brand)}
.dropdown>button svg{transition:transform .2s}
.dropdown.open>button svg{transform:rotate(180deg)}
.dropdown-menu{
  position:absolute;right:0;top:calc(100% + 8px);min-width:290px;
  background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);
  box-shadow:var(--shadow-lg);padding:8px;display:none;
  grid-template-columns:1fr 1fr;gap:2px;
}
.dropdown.open .dropdown-menu{display:grid}
.dropdown-menu a{
  padding:8px 10px;border-radius:9px;font-size:.87rem;font-weight:600;color:var(--text-soft);
}
.dropdown-menu a:hover{background:var(--bg-soft);color:var(--brand);text-decoration:none}

.icon-btn{
  width:42px;height:42px;display:grid;place-items:center;border-radius:11px;
  border:1px solid var(--border);background:var(--surface);color:var(--text-soft);cursor:pointer;
  transition:.15s;
}
.icon-btn:hover{border-color:var(--brand);color:var(--brand)}
.icon-btn svg{width:18px;height:18px}
.mobile-nav{display:none}
.theme-toggle .moon{display:none}
[data-theme="dark"] .theme-toggle .moon{display:block}
[data-theme="dark"] .theme-toggle .sun{display:none}
.nav-toggle{display:none}

@media (max-width:900px){
  .nav-links,.dropdown{display:none}
  .nav-toggle{display:grid}
  .mobile-nav{
    display:none;border-top:1px solid var(--border);background:var(--surface);
    padding:10px 0 18px;max-height:calc(100vh - 64px);overflow-y:auto;
  }
  .mobile-nav.open{display:block}
  .mobile-nav h4{font-size:.72rem;text-transform:uppercase;letter-spacing:.09em;color:var(--text-mute);margin:14px 0 6px;padding-inline:4px}
  .mobile-nav ul{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:1fr 1fr;gap:4px}
  .mobile-nav a{display:block;padding:11px 12px;border-radius:11px;background:var(--surface-2);font-size:.9rem;font-weight:600;color:var(--text-soft)}
  .mobile-nav a:hover{text-decoration:none;color:var(--brand)}
}

/* ---------- 4. HERO ---------- */
.hero{
  position:relative;overflow:hidden;
  background:
    radial-gradient(900px 400px at 12% -8%,rgba(99,102,241,.22),transparent 62%),
    radial-gradient(700px 380px at 92% 4%,rgba(20,184,166,.20),transparent 60%),
    var(--bg-soft);
  border-bottom:1px solid var(--border);
  padding:44px 0 40px;
}
.hero-grid{display:grid;grid-template-columns:minmax(0,1fr);gap:28px;align-items:start}
@media (min-width:980px){
  .hero{padding:58px 0 54px}
  .hero-grid{grid-template-columns:minmax(0,1fr) minmax(0,520px);gap:44px}
}
.eyebrow{
  display:inline-flex;align-items:center;gap:7px;font-size:.78rem;font-weight:700;
  text-transform:uppercase;letter-spacing:.08em;color:var(--accent);
  background:var(--surface);border:1px solid var(--border);
  padding:6px 12px;border-radius:999px;margin-bottom:14px;
}
.eyebrow svg{width:15px;height:15px;flex:0 0 15px}
.hero h1{margin-bottom:.45em}
.grad-text{background:linear-gradient(120deg,var(--indigo-600),var(--teal-600));-webkit-background-clip:text;background-clip:text;color:transparent}
[data-theme="dark"] .grad-text{background:linear-gradient(120deg,#a5b4fc,#5eead4);-webkit-background-clip:text;background-clip:text;color:transparent}
.lead{font-size:1.06rem;color:var(--text-soft);max-width:56ch}
.hero-points{list-style:none;padding:0;margin:18px 0 0;display:grid;gap:8px}
.hero-points li{display:flex;gap:9px;align-items:flex-start;font-size:.94rem;color:var(--text-soft);margin:0}
.hero-points svg{width:19px;height:19px;flex:0 0 19px;color:var(--teal-600);margin-top:2px}
.btn-row{display:flex;flex-wrap:wrap;gap:10px;margin-top:22px}

/* ---------- 5. CALCULATOR ---------- */
.calc{
  background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius-xl);box-shadow:var(--shadow-lg);overflow:hidden;
}
.calc-head{padding:18px 18px 0}
.calc-head h2{font-size:1.15rem;margin-bottom:4px}
.calc-head p{font-size:.88rem;color:var(--text-mute);margin-bottom:14px}

.tabs{display:flex;gap:4px;padding:5px;background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius);margin:0 18px 18px;overflow-x:auto;scrollbar-width:none}
.tabs::-webkit-scrollbar{display:none}
.tab{
  flex:1 0 auto;white-space:nowrap;border:0;background:none;cursor:pointer;font:inherit;
  font-size:.85rem;font-weight:700;color:var(--text-mute);padding:11px 14px;border-radius:10px;
  min-height:42px;transition:.15s;
}
.tab:hover{color:var(--brand)}
.tab[aria-selected="true"]{background:var(--surface);color:var(--brand);box-shadow:var(--shadow-sm)}
[data-theme="dark"] .tab[aria-selected="true"]{background:#223054}

.calc-body{padding:0 18px 20px}
.panel[hidden]{display:none}
.field-row{display:grid;gap:14px}
@media (min-width:560px){.field-row.two{grid-template-columns:1fr 1fr}.field-row.three{grid-template-columns:repeat(3,1fr)}}
.field{display:flex;flex-direction:column;gap:6px}
.field label{font-size:.85rem;font-weight:700;color:var(--text-soft)}
.input-wrap{position:relative;display:flex;align-items:center}
.input{
  width:100%;height:52px;padding:0 14px;font:inherit;font-size:1.02rem;font-weight:600;
  color:var(--text);background:var(--surface-2);
  border:1.5px solid var(--border-strong);border-radius:var(--radius);
  transition:border-color .15s,box-shadow .15s;-moz-appearance:textfield;
}
.input::-webkit-outer-spin-button,.input::-webkit-inner-spin-button{-webkit-appearance:none;margin:0}
.input:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 4px rgba(99,102,241,.16);background:var(--surface)}
.input.invalid{border-color:var(--rose-500);box-shadow:0 0 0 4px rgba(244,63,94,.12)}
.input-wrap .suffix{position:absolute;right:14px;font-weight:700;color:var(--text-mute);pointer-events:none;font-size:.95rem}
.input-wrap:has(.suffix) .input{padding-right:40px}
.hint{font-size:.78rem;color:var(--text-mute)}
.err{font-size:.82rem;font-weight:600;color:var(--rose-500);min-height:0}
.err:empty{display:none}

.actions{display:flex;flex-wrap:wrap;gap:9px;margin-top:16px}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  font:inherit;font-size:.95rem;font-weight:700;cursor:pointer;
  padding:0 20px;height:48px;border-radius:var(--radius);border:1.5px solid transparent;
  transition:transform .12s,box-shadow .15s,background .15s;text-decoration:none;
}
.btn:hover{text-decoration:none}
.btn:active{transform:translateY(1px)}
.btn-primary{
  background:linear-gradient(135deg,var(--indigo-600),var(--indigo-700));color:#fff;
  box-shadow:0 10px 20px -10px rgba(79,70,229,.9);flex:1 1 150px;
}
.btn-primary:hover{background:linear-gradient(135deg,var(--indigo-700),#3730a3);color:#fff}
.btn-ghost{background:var(--surface-2);border-color:var(--border-strong);color:var(--text-soft)}
.btn-ghost:hover{border-color:var(--brand);color:var(--brand)}
.btn-accent{background:var(--teal-600);color:#fff}
.btn-accent:hover{background:var(--teal-500);color:#fff}
.btn-sm{height:38px;padding:0 13px;font-size:.83rem;border-radius:10px}
.btn svg{width:17px;height:17px}

.result{
  margin-top:18px;border-radius:var(--radius-lg);padding:18px;
  background:linear-gradient(160deg,rgba(20,184,166,.10),rgba(99,102,241,.10));
  border:1.5px solid color-mix(in srgb,var(--teal-500) 30%,transparent);
}
.result[hidden]{display:none}
.result-label{font-size:.78rem;font-weight:700;text-transform:uppercase;letter-spacing:.08em;color:var(--text-mute)}
.result-value{font-size:clamp(1.9rem,7vw,2.6rem);font-weight:800;letter-spacing:-.03em;line-height:1.15;color:var(--text);word-break:break-word}
.result-extra{display:grid;gap:8px;margin-top:12px}
.result-extra div{display:flex;justify-content:space-between;gap:12px;font-size:.93rem;padding:9px 12px;background:var(--surface);border-radius:10px;border:1px solid var(--border)}
.result-extra span:first-child{color:var(--text-soft);font-weight:600}
.result-extra span:last-child{font-weight:800}
.result-actions{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}
.steps{margin-top:14px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:14px 16px}
.steps h4{font-size:.8rem;text-transform:uppercase;letter-spacing:.07em;color:var(--text-mute);margin:0 0 8px}
.steps ol{margin:0;padding-left:1.15rem}
.steps li{font-size:.92rem;color:var(--text-soft)}
.steps code{font-family:var(--mono);font-size:.88rem;background:var(--bg-soft);padding:2px 6px;border-radius:6px;color:var(--text)}
.toast{
  position:fixed;left:50%;bottom:24px;transform:translate(-50%,20px);
  background:var(--text);color:var(--bg);padding:11px 20px;border-radius:999px;
  font-size:.88rem;font-weight:700;opacity:0;pointer-events:none;transition:.25s;z-index:300;
}
.toast.show{opacity:1;transform:translate(-50%,0)}

.history{margin-top:18px;border:1px dashed var(--border-strong);border-radius:var(--radius);padding:14px 16px;background:var(--surface)}
.history[hidden]{display:none}
.history-head{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:8px}
.history-head h3{font-size:.82rem;text-transform:uppercase;letter-spacing:.07em;color:var(--text-mute);margin:0}
.history ul{list-style:none;margin:0;padding:0;display:grid;gap:6px}
.history li{font-size:.88rem;color:var(--text-soft);background:var(--surface-2);padding:8px 11px;border-radius:9px;border:1px solid var(--border);margin:0}
.link-btn{background:none;border:0;padding:0;font:inherit;font-size:.82rem;font-weight:700;color:var(--brand);cursor:pointer;text-decoration:underline}

/* ---------- 6. CARDS / GRIDS ---------- */
.section{padding:48px 0}
.section.tight{padding:34px 0}
.section-head{max-width:64ch;margin-bottom:26px}
.section-head p{color:var(--text-soft)}
.grid{display:grid;grid-template-columns:minmax(0,1fr);gap:14px}
.grid.c2{grid-template-columns:1fr}
.grid.c3{grid-template-columns:1fr}
@media (min-width:640px){.grid.c2,.grid.c3{grid-template-columns:1fr 1fr}}
@media (min-width:960px){.grid.c3{grid-template-columns:repeat(3,1fr)}}

.card{
  display:block;background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius-lg);padding:18px;box-shadow:var(--shadow-sm);
  transition:transform .18s,box-shadow .18s,border-color .18s;color:inherit;
}
a.card:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:color-mix(in srgb,var(--brand) 45%,var(--border));text-decoration:none}
.card-icon{
  width:40px;height:40px;border-radius:12px;display:grid;place-items:center;margin-bottom:12px;
  background:var(--indigo-50);color:var(--indigo-600);font-weight:800;font-size:1.05rem;
}
[data-theme="dark"] .card-icon{background:rgba(99,102,241,.18);color:#a5b4fc}
.card-icon.teal{background:var(--teal-50);color:var(--teal-600)}
[data-theme="dark"] .card-icon.teal{background:rgba(20,184,166,.16);color:#5eead4}
.card h3{font-size:1.02rem;margin-bottom:5px}
.card p{font-size:.89rem;color:var(--text-soft);margin:0}
.card .go{display:inline-flex;align-items:center;gap:5px;margin-top:10px;font-size:.85rem;font-weight:700;color:var(--brand)}

/* ---------- 7. CONTENT ---------- */
.prose{max-width:74ch}
.prose h2{margin-top:2em}
.prose h2:first-child{margin-top:0}
.prose h3{margin-top:1.6em}
.prose p,.prose li{color:var(--text-soft)}
.prose strong{color:var(--text)}
.formula{
  background:var(--surface);border:1px solid var(--border);border-left:4px solid var(--teal-500);
  border-radius:var(--radius);padding:16px 18px;margin:18px 0;
  font-family:var(--mono);font-size:.95rem;color:var(--text);overflow-x:auto;line-height:1.9;
}
.formula .lbl{font-family:var(--font);font-size:.74rem;font-weight:700;text-transform:uppercase;letter-spacing:.08em;color:var(--text-mute);display:block;margin-bottom:6px}
.callout{
  background:var(--surface);border:1px solid var(--border);border-left:4px solid var(--amber-500);
  border-radius:var(--radius);padding:15px 18px;margin:18px 0;font-size:.94rem;color:var(--text-soft);
}
.callout strong{display:block;color:var(--text);margin-bottom:3px}
.example{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:18px;margin:18px 0}
.example h4{margin:0 0 10px;font-size:.98rem}
.example ol{margin:0;padding-left:1.2rem}
.table-wrap{overflow-x:auto;margin:18px 0;border:1px solid var(--border);border-radius:var(--radius);background:var(--surface)}
table{width:100%;border-collapse:collapse;font-size:.9rem;min-width:420px}
th,td{padding:11px 14px;text-align:left;border-bottom:1px solid var(--border)}
th{background:var(--surface-2);font-weight:700;font-size:.82rem;text-transform:uppercase;letter-spacing:.05em;color:var(--text-mute)}
tr:last-child td{border-bottom:0}
td.pass{color:var(--teal-600);font-weight:700}

.faq{display:grid;gap:10px}
.faq details{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden}
.faq summary{
  cursor:pointer;padding:15px 18px;font-weight:700;font-size:.97rem;list-style:none;
  display:flex;justify-content:space-between;gap:12px;align-items:center;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-size:1.3rem;font-weight:700;color:var(--brand);line-height:1}
.faq details[open] summary::after{content:"−"}
.faq details[open] summary{border-bottom:1px solid var(--border)}
.faq .answer{padding:14px 18px 4px;color:var(--text-soft);font-size:.94rem}

.breadcrumb{padding:14px 0 0;font-size:.82rem;color:var(--text-mute)}
.breadcrumb ol{list-style:none;display:flex;flex-wrap:wrap;gap:6px;padding:0;margin:0}
.breadcrumb li{margin:0;display:flex;gap:6px;align-items:center}
.breadcrumb li+li::before{content:"/";color:var(--border-strong)}
.breadcrumb a{color:var(--text-mute);font-weight:600}
.breadcrumb a:hover{color:var(--brand)}

.related{display:grid;gap:8px;grid-template-columns:1fr}
@media (min-width:560px){.related{grid-template-columns:1fr 1fr}}
.related a{
  display:flex;align-items:center;gap:8px;padding:12px 14px;background:var(--surface);
  border:1px solid var(--border);border-radius:var(--radius);font-size:.9rem;font-weight:600;color:var(--text-soft);
}
.related a:hover{border-color:var(--brand);color:var(--brand);text-decoration:none}
.related a::before{content:"→";color:var(--brand);font-weight:800}

/* ---------- 8. AD SLOTS ---------- */
.ad-slot{
  display:grid;place-items:center;text-align:center;
  border:1px dashed var(--border-strong);border-radius:var(--radius);
  background:var(--surface-2);color:var(--text-mute);
  font-size:.72rem;text-transform:uppercase;letter-spacing:.12em;font-weight:700;
  margin:26px auto;padding:14px;min-height:100px;width:100%;
}
.ad-slot.leaderboard{min-height:100px}
.ad-slot.inline{min-height:250px}
@media (max-width:640px){.ad-slot{min-height:100px}}

/* ---------- 9. FOOTER ---------- */
.site-footer{background:var(--surface);border-top:1px solid var(--border);padding:44px 0 26px;margin-top:40px}
.footer-grid{display:grid;gap:26px;grid-template-columns:1fr}
@media (min-width:720px){.footer-grid{grid-template-columns:1.6fr 1fr 1fr 1fr}}
.footer-brand p{font-size:.89rem;color:var(--text-mute);max-width:36ch;margin-top:10px}
.site-footer h4{font-size:.78rem;text-transform:uppercase;letter-spacing:.09em;color:var(--text-mute);margin-bottom:10px}
.site-footer ul{list-style:none;padding:0;margin:0}
.site-footer li{margin-bottom:7px}
.site-footer li a{font-size:.9rem;color:var(--text-soft);font-weight:600}
.site-footer li a:hover{color:var(--brand)}
.footer-bottom{
  margin-top:30px;padding-top:18px;border-top:1px solid var(--border);
  display:flex;flex-wrap:wrap;gap:10px;justify-content:space-between;
  font-size:.83rem;color:var(--text-mute);
}

/* ---------- 10. UTILITIES ---------- */
.center{text-align:center}
.mt-0{margin-top:0}.mb-0{margin-bottom:0}
.muted{color:var(--text-mute)}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.page-head{padding:26px 0 8px}
.page-head .lead{margin-bottom:0}
@media (prefers-reduced-motion:reduce){
  *{animation-duration:.01ms!important;transition-duration:.01ms!important;scroll-behavior:auto!important}
}
@media print{.site-header,.site-footer,.ad-slot,.actions,.result-actions{display:none!important}}