/* =========================================================
   CALCURA — Precision Instrument design system
   Palette: paper #EEF3F1 / ink #12241F / lcd #1F7A54
            lcd-bright #34D399 / amber #E8890C / blueprint #2E5266
   Type: IBM Plex Sans (display+body) / IBM Plex Mono (all digits)
   ========================================================= */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:ital,wght@0,400;0,500;0,600;0,700;1,400&family=IBM+Plex+Mono:wght@400;500;600;700&display=swap');

:root{
  --paper:#EEF3F1;
  --paper-alt:#E1EAE5;
  --surface:#FFFFFF;
  --ink:#12241F;
  --ink-soft:#3C4F49;
  --ink-faint:#6E7F79;
  --line:#C7D2CC;
  --lcd:#1F7A54;
  --lcd-bright:#20B872;
  --lcd-glow:#34D39955;
  --amber:#E8890C;
  --amber-soft:#FCEBD2;
  --blueprint:#2E5266;
  --danger:#C4453A;
  --radius-s:6px;
  --radius-m:10px;
  --radius-l:16px;
  --shadow-s:0 1px 2px rgba(18,36,31,.06), 0 1px 1px rgba(18,36,31,.04);
  --shadow-m:0 6px 20px rgba(18,36,31,.08), 0 2px 6px rgba(18,36,31,.05);
  --shadow-l:0 20px 45px rgba(18,36,31,.14), 0 6px 16px rgba(18,36,31,.08);
  --font-sans:'IBM Plex Sans', system-ui, sans-serif;
  --font-mono:'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --container:1180px;
  color-scheme: light;
}

html[data-theme="dark"]{
  --paper:#0E1A16;
  --paper-alt:#122822;
  --surface:#152B25;
  --ink:#EAF3EF;
  --ink-soft:#B7C9C2;
  --ink-faint:#7E9891;
  --line:#264A3F;
  --lcd:#34D399;
  --lcd-bright:#5CF0B4;
  --amber:#F3A93A;
  --amber-soft:#3A2E14;
  --blueprint:#8FC3DE;
  --shadow-m:0 6px 24px rgba(0,0,0,.35);
  --shadow-l:0 24px 50px rgba(0,0,0,.5);
  color-scheme: dark;
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family:var(--font-sans);
  color:var(--ink);
  background:
    linear-gradient(var(--line) 1px, transparent 1px) 0 0/40px 40px,
    linear-gradient(90deg, var(--line) 1px, transparent 1px) 0 0/40px 40px,
    var(--paper);
  background-attachment: fixed;
  -webkit-font-smoothing:antialiased;
  transition:background-color .25s ease, color .25s ease;
}
html[data-theme="dark"] body{ opacity:.98; }
img{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
h1,h2,h3,h4{font-family:var(--font-sans);font-weight:700;line-height:1.15;margin:0 0 .5em;letter-spacing:-0.01em;}
p{line-height:1.7;color:var(--ink-soft);margin:0 0 1em;}
.container{max-width:var(--container);margin:0 auto;padding:0 24px;}
.mono{font-family:var(--font-mono);}
:focus-visible{outline:2px solid var(--lcd);outline-offset:2px;border-radius:4px;}
@media (prefers-reduced-motion: reduce){
  *{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important;scroll-behavior:auto !important;}
}

/* ---------- eyebrow / catalog labels ---------- */
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;
  text-transform:uppercase;color:var(--lcd);font-weight:600;
}
.eyebrow::before{content:"";width:16px;height:1px;background:var(--lcd);display:inline-block;}

/* ---------- header ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:68px;gap:20px;}
.logo{display:flex;align-items:center;gap:10px;font-weight:700;font-size:19px;color:var(--ink);flex-shrink:0;}
.logo .logo-badge{
  width:34px;height:34px;border-radius:8px;background:var(--ink);color:var(--lcd-bright);
  display:flex;align-items:center;justify-content:center;font-family:var(--font-mono);font-weight:700;
  font-size:15px;box-shadow:inset 0 0 0 1px #0003;
}
.logo span{font-family:var(--font-mono);}
.logo small{display:block;font-family:var(--font-sans);font-weight:400;font-size:10px;color:var(--ink-faint);letter-spacing:.08em;}
.main-nav{display:flex;gap:4px;align-items:center;}
.main-nav a{
  font-size:14px;font-weight:500;color:var(--ink-soft);padding:8px 14px;border-radius:var(--radius-s);
  transition:background .18s ease, color .18s ease;
}
.main-nav a:hover{background:var(--surface);color:var(--ink);}
.header-actions{display:flex;align-items:center;gap:8px;}
.icon-btn{
  width:38px;height:38px;border-radius:var(--radius-s);border:1px solid var(--line);
  background:var(--surface);color:var(--ink);display:flex;align-items:center;justify-content:center;
  cursor:pointer;transition:transform .15s ease, box-shadow .15s ease;font-size:16px;
}
.icon-btn:hover{box-shadow:var(--shadow-s);transform:translateY(-1px);}
.nav-toggle{display:none;}

/* ---------- language switcher ---------- */
.lang-switch{position:relative;}
.lang-btn{width:auto;padding:0 12px;font-family:var(--font-mono);font-size:12px;font-weight:600;letter-spacing:.04em;}
.lang-menu{
  position:absolute;top:calc(100% + 8px);right:0;background:var(--surface);border:1px solid var(--line);
  border-radius:var(--radius-m);box-shadow:var(--shadow-m);padding:6px;min-width:190px;
  opacity:0;transform:translateY(-6px);pointer-events:none;transition:all .16s ease;z-index:60;
}
.lang-menu.open{opacity:1;transform:translateY(0);pointer-events:auto;}
.lang-menu a{display:block;font-size:13.5px;padding:9px 10px;border-radius:var(--radius-s);color:var(--ink-soft);}
.lang-menu a:hover{background:var(--paper);color:var(--ink);}
.lang-menu a.active{color:var(--lcd);font-weight:600;}

@media (max-width:900px){
  .main-nav{
    position:fixed;inset:68px 0 auto 0;background:var(--surface);border-bottom:1px solid var(--line);
    flex-direction:column;align-items:stretch;padding:10px;gap:2px;
    transform:translateY(-8px);opacity:0;pointer-events:none;transition:all .2s ease;box-shadow:var(--shadow-m);
  }
  .main-nav.open{transform:translateY(0);opacity:1;pointer-events:auto;}
  .main-nav a{padding:12px 14px;border-radius:var(--radius-s);}
  .nav-toggle{display:flex;}
}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  font-family:var(--font-sans);font-weight:600;font-size:14px;
  padding:12px 20px;border-radius:var(--radius-s);border:1px solid transparent;cursor:pointer;
  transition:transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn-primary{background:var(--ink);color:var(--paper);}
.btn-primary:hover{transform:translateY(-2px);box-shadow:var(--shadow-m);}
.btn-ghost{background:transparent;border-color:var(--line);color:var(--ink);}
.btn-ghost:hover{background:var(--surface);}

/* ---------- hero / LCD screen ---------- */
.hero{padding:64px 0 56px;}
.hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:56px;align-items:center;}
@media (max-width:900px){.hero-grid{grid-template-columns:1fr;gap:36px;}}
.hero h1{font-size:clamp(34px,4.6vw,54px);margin-bottom:.32em;}
.hero h1 em{font-style:normal;color:var(--lcd);}
.hero p.lead{font-size:17px;max-width:46ch;}
.hero-actions{display:flex;gap:12px;margin-top:22px;flex-wrap:wrap;}

.search-shell{margin-top:26px;}
.search-box{
  display:flex;align-items:center;gap:10px;background:var(--surface);border:1px solid var(--line);
  border-radius:var(--radius-m);padding:12px 16px;box-shadow:var(--shadow-s);
}
.search-box input{
  border:none;outline:none;background:transparent;flex:1;font-size:15px;font-family:var(--font-sans);color:var(--ink);
}
.search-box .kbd{font-family:var(--font-mono);font-size:11px;color:var(--ink-faint);border:1px solid var(--line);
  border-radius:4px;padding:2px 6px;}

.lcd-screen{
  background:var(--ink);border-radius:var(--radius-l);padding:26px 26px 20px;
  box-shadow:var(--shadow-l), inset 0 0 0 6px #00000022;position:relative;overflow:hidden;
}
.lcd-screen::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:repeating-linear-gradient(0deg, #ffffff08 0 1px, transparent 1px 3px);
}
.lcd-screen .lcd-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px;}
.lcd-screen .lcd-top span{font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;color:var(--lcd-bright);text-transform:uppercase;opacity:.8;}
.lcd-screen .dot{width:7px;height:7px;border-radius:50%;background:var(--lcd-bright);box-shadow:0 0 8px var(--lcd-bright);}
.lcd-expr{font-family:var(--font-mono);font-size:15px;color:#8fe6c4;min-height:20px;opacity:.85;}
.lcd-result{
  font-family:var(--font-mono);font-weight:600;color:var(--lcd-bright);
  font-size:clamp(30px,4vw,44px);letter-spacing:.01em;text-shadow:0 0 18px var(--lcd-glow);
  min-height:52px;display:flex;align-items:flex-end;
}
.lcd-label{font-family:var(--font-mono);font-size:12px;color:#6fae94;margin-top:6px;}
.lcd-tags{display:flex;gap:8px;margin-top:20px;flex-wrap:wrap;}
.lcd-tags span{
  font-family:var(--font-mono);font-size:11px;color:#bfe9d5;border:1px solid #ffffff22;border-radius:20px;
  padding:5px 10px;background:#ffffff0a;
}

/* ---------- stat strip ---------- */
.stat-strip{display:flex;gap:0;border:1px solid var(--line);border-radius:var(--radius-m);overflow:hidden;margin-top:18px;background:var(--surface);}
.stat-strip div{flex:1;padding:14px 16px;border-right:1px solid var(--line);}
.stat-strip div:last-child{border-right:none;}
.stat-strip b{display:block;font-family:var(--font-mono);font-size:20px;}
.stat-strip span{font-size:12px;color:var(--ink-faint);}

/* ---------- ad slot ---------- */
.ad-slot{
  border:1px dashed var(--line);border-radius:var(--radius-m);background:var(--paper-alt);
  color:var(--ink-faint);font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  text-transform:uppercase;display:flex;align-items:center;justify-content:center;
  padding:18px;margin:36px 0;min-height:90px;text-align:center;
}
.ad-slot.leader{min-height:100px;}
.ad-slot.side{min-height:250px;}

/* ---------- section ---------- */
.section{padding:56px 0;}
.section-head{display:flex;align-items:flex-end;justify-content:space-between;gap:20px;margin-bottom:26px;flex-wrap:wrap;}
.section-head h2{font-size:26px;}
.section-head p{margin:6px 0 0;max-width:60ch;}
.pill{
  font-family:var(--font-mono);font-size:11px;padding:5px 10px;border-radius:20px;border:1px solid var(--line);
  color:var(--ink-faint);
}

/* ---------- calculator grid / cards ---------- */
.calc-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px;}
.calc-card{
  position:relative;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-m);
  padding:20px;display:flex;flex-direction:column;gap:10px;transition:transform .18s ease, box-shadow .18s ease, border-color .18s ease;
  overflow:hidden;
}
.calc-card::before{
  content:"";position:absolute;top:0;left:0;right:0;height:3px;background:var(--accent-color,var(--lcd));
  transform:scaleX(0);transform-origin:left;transition:transform .2s ease;
}
.calc-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-m);border-color:transparent;}
.calc-card:hover::before{transform:scaleX(1);}
.calc-card .code{font-family:var(--font-mono);font-size:11px;color:var(--accent-color,var(--lcd));letter-spacing:.06em;}
.calc-card h3{font-size:16.5px;margin:0;}
.calc-card p{font-size:13.5px;margin:0;flex:1;}
.calc-card .go{font-family:var(--font-mono);font-size:12px;color:var(--ink-faint);display:flex;align-items:center;gap:6px;}
.calc-card:hover .go{color:var(--ink);}

/* category accent colors as inline custom prop via class */
.acc-financial{--accent-color:#1F7A54;}
.acc-health{--accent-color:#C4453A;}
.acc-math{--accent-color:#2E5266;}
.acc-everyday{--accent-color:#E8890C;}

/* ---------- category section wrapper ---------- */
.cat-block{padding:44px 0;border-top:1px solid var(--line);}
.cat-title{display:flex;align-items:center;gap:12px;margin-bottom:4px;}
.cat-title h2{margin:0;font-size:22px;}
.cat-swatch{width:10px;height:10px;border-radius:3px;}

/* ---------- calculator page layout ---------- */
.breadcrumb{font-family:var(--font-mono);font-size:12px;color:var(--ink-faint);padding:20px 0 0;}
.breadcrumb a{color:var(--blueprint);}
.calc-page-head{padding:18px 0 30px;}
.calc-page-head h1{font-size:clamp(26px,3.4vw,36px);margin-bottom:8px;}
.calc-page-head p{font-size:15.5px;max-width:70ch;}

.calc-layout{display:grid;grid-template-columns:1fr 380px;gap:28px;align-items:start;}
@media (max-width:980px){.calc-layout{grid-template-columns:1fr;}}

.panel{
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-l);
  padding:26px;box-shadow:var(--shadow-s);
}
.panel h2.panel-title{font-size:14px;font-family:var(--font-mono);text-transform:uppercase;letter-spacing:.1em;color:var(--ink-faint);margin-bottom:20px;}

.field{margin-bottom:18px;}
.field label{display:block;font-size:13.5px;font-weight:600;margin-bottom:6px;color:var(--ink);}
.field .hint{font-size:12px;color:var(--ink-faint);margin-top:5px;}
.field input[type="text"],.field input[type="number"],.field input[type="date"],.field select{
  width:100%;font-family:var(--font-mono);font-size:15px;padding:11px 12px;border:1px solid var(--line);
  border-radius:var(--radius-s);background:var(--paper);color:var(--ink);transition:border-color .15s ease, box-shadow .15s ease;
}
.field input:focus,.field select:focus{border-color:var(--lcd);box-shadow:0 0 0 3px var(--lcd-glow);outline:none;}
.field-row{display:grid;grid-template-columns:1fr 1fr;gap:14px;}
@media (max-width:480px){.field-row{grid-template-columns:1fr;}}

.unit-toggle{display:inline-flex;border:1px solid var(--line);border-radius:20px;padding:3px;background:var(--paper);margin-bottom:20px;}
.unit-toggle button{
  border:none;background:transparent;font-family:var(--font-mono);font-size:12px;padding:6px 14px;border-radius:16px;
  cursor:pointer;color:var(--ink-faint);
}
.unit-toggle button.active{background:var(--ink);color:var(--paper);}

.radio-row{display:flex;gap:10px;flex-wrap:wrap;}
.radio-chip{
  border:1px solid var(--line);border-radius:20px;padding:8px 16px;font-size:13.5px;cursor:pointer;
  background:var(--paper);transition:all .15s ease;
}
.radio-chip input{display:none;}
.radio-chip.active{background:var(--ink);color:var(--paper);border-color:var(--ink);}

input[type="range"]{width:100%;accent-color:var(--lcd);}

/* result panel */
.result-panel{position:sticky;top:88px;}
.result-lcd{
  background:var(--ink);border-radius:var(--radius-l);padding:22px;color:var(--paper);position:relative;overflow:hidden;
  box-shadow:var(--shadow-l);
}
.result-lcd::before{content:"";position:absolute;inset:0;pointer-events:none;
  background:repeating-linear-gradient(0deg, #ffffff08 0 1px, transparent 1px 3px);}
.result-lcd .r-label{font-family:var(--font-mono);font-size:11px;text-transform:uppercase;letter-spacing:.1em;color:#7fd6ac;margin-bottom:6px;}
.result-lcd .r-value{font-family:var(--font-mono);font-weight:700;font-size:clamp(28px,3vw,38px);color:var(--lcd-bright);text-shadow:0 0 16px var(--lcd-glow);word-break:break-word;}
.result-lcd .r-sub{font-family:var(--font-mono);font-size:12px;color:#8fb5a6;margin-top:8px;}
.result-rows{margin-top:16px;border-top:1px dashed #ffffff22;padding-top:14px;display:flex;flex-direction:column;gap:9px;}
.result-rows div{display:flex;justify-content:space-between;font-size:13px;color:#c7ddd1;}
.result-rows div b{font-family:var(--font-mono);color:var(--paper);font-weight:600;}

.gauge{height:10px;border-radius:6px;margin-top:14px;position:relative;
  background:linear-gradient(90deg,#3B82F6 0 25%, var(--lcd) 25% 50%, var(--amber) 50% 75%, var(--danger) 75% 100%);}
.gauge .marker{position:absolute;top:-4px;width:3px;height:18px;background:var(--ink);border-radius:2px;box-shadow:0 0 0 2px var(--paper);transition:left .3s ease;}
html[data-theme="dark"] .gauge .marker{box-shadow:0 0 0 2px var(--surface);}

.badge{display:inline-flex;align-items:center;gap:6px;font-family:var(--font-mono);font-size:12px;padding:5px 12px;border-radius:20px;margin-top:10px;}
.badge-info{background:#DCEFE6;color:#1F7A54;}
.badge-warn{background:var(--amber-soft);color:var(--amber);}
.badge-danger{background:#F7DEDB;color:var(--danger);}
html[data-theme="dark"] .badge-info{background:#123324;}
html[data-theme="dark"] .badge-danger{background:#3A1C18;}

/* explanation + faq */
.prose{max-width:74ch;}
.prose h2{font-size:21px;margin-top:36px;}
.faq{border-top:1px solid var(--line);margin-top:10px;}
.faq-item{border-bottom:1px solid var(--line);}
.faq-q{
  width:100%;text-align:left;background:none;border:none;padding:16px 4px;cursor:pointer;
  display:flex;justify-content:space-between;align-items:center;font-weight:600;font-size:15px;color:var(--ink);
  font-family:var(--font-sans);
}
.faq-q::after{content:"+";font-family:var(--font-mono);font-size:18px;color:var(--lcd);transition:transform .2s ease;}
.faq-item.open .faq-q::after{transform:rotate(45deg);}
.faq-a{max-height:0;overflow:hidden;transition:max-height .25s ease;}
.faq-item.open .faq-a{max-height:280px;}
.faq-a p{padding:0 4px 16px;font-size:14px;}

/* related */
.related-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:12px;margin-top:14px;}
.related-grid a{
  border:1px solid var(--line);border-radius:var(--radius-s);padding:12px 14px;font-size:13.5px;font-weight:500;
  background:var(--surface);transition:all .15s ease;
}
.related-grid a:hover{border-color:var(--lcd);color:var(--lcd);}

/* standard calculator keypad */
.calc-device-wrap{
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-l);
  box-shadow:var(--shadow-s);padding:36px;display:flex;justify-content:center;
}
.calc-device{background:var(--ink);border-radius:var(--radius-l);padding:28px;max-width:440px;width:100%;box-shadow:var(--shadow-l);border:1px solid rgba(255,255,255,.06);}
.calc-device .display{
  background:#0a1512;border-radius:var(--radius-m);padding:26px 20px;margin-bottom:18px;text-align:right;
}
.calc-device .display .prev{font-family:var(--font-mono);font-size:15px;color:#6fae94;min-height:20px;overflow-wrap:anywhere;}
.calc-device .display .cur{font-family:var(--font-mono);font-size:44px;color:var(--lcd-bright);text-shadow:0 0 14px var(--lcd-glow);overflow-wrap:anywhere;}
.keypad{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;}
.keypad button{
  font-family:var(--font-mono);font-size:20px;padding:22px 0;border-radius:var(--radius-s);border:none;cursor:pointer;
  background:#1c332c;color:var(--paper);transition:transform .1s ease, background .15s ease;
}
.keypad button:active{transform:scale(.94);}
.keypad button.op{background:#26463b;color:var(--lcd-bright);}
.keypad button.eq{background:var(--lcd);color:#06231a;font-weight:700;}
.keypad button.fn{background:#2c2118;color:var(--amber);}
.keypad button.wide{grid-column:span 2;}
@media (max-width:600px){
  .calc-device-wrap{padding:16px;}
  .calc-device{padding:18px;}
  .calc-device .display .cur{font-size:34px;}
  .keypad button{font-size:17px;padding:17px 0;}
}


/* footer */
.site-footer{border-top:1px solid var(--line);margin-top:60px;padding:44px 0 26px;background:var(--paper-alt);}
.footer-grid{display:grid;grid-template-columns:1.4fr repeat(4,1fr);gap:24px;}
@media (max-width:820px){.footer-grid{grid-template-columns:repeat(2,1fr);}}
.footer-grid h4{font-family:var(--font-mono);font-size:12px;text-transform:uppercase;letter-spacing:.1em;color:var(--ink-faint);margin-bottom:12px;}
.footer-grid a{display:block;font-size:13.5px;color:var(--ink-soft);padding:4px 0;}
.footer-grid a:hover{color:var(--lcd);}
.footer-bottom{display:flex;justify-content:space-between;align-items:center;margin-top:36px;padding-top:20px;border-top:1px solid var(--line);flex-wrap:wrap;gap:10px;}
.footer-bottom p{margin:0;font-size:12.5px;color:var(--ink-faint);}

/* legal pages */
.legal-page{padding:44px 0 80px;}
.legal-page .prose{max-width:78ch;}
.legal-page h2{margin-top:32px;}

/* utility */
.mt-0{margin-top:0;}
.reveal{opacity:0;transform:translateY(14px);transition:opacity .5s ease, transform .5s ease;}
.reveal.in{opacity:1;transform:translateY(0);}