/* ========================================================================
   SIPCalculators.net — Clean Minimal Design (Apple-inspired)
   v3: Fully responsive, dark mode, enhanced animations
   ======================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

/* ============================================================
   Design Tokens — Light
   ============================================================ */
:root{
  --bg: #fbfbfd;
  --surface: #ffffff;
  --ink: #1d1d1f;
  --ink-2: #424245;
  --muted: #86868b;
  --line: #e8e8ed;
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --accent-soft: rgba(0,113,227,.08);
  --green: #34c759;
  --red: #ff3b30;

  --r: 12px;
  --r-lg: 16px;
  --r-xl: 20px;
  --shadow: 0 2px 8px rgba(0,0,0,.04), 0 0 0 1px rgba(0,0,0,.03);
  --shadow-hover: 0 4px 20px rgba(0,0,0,.08), 0 0 0 1px rgba(0,0,0,.04);
  --ease: cubic-bezier(.25,.1,.25,1);
  --spring: cubic-bezier(.34,1.56,.64,1);
  color-scheme: light dark;
}

/* ============================================================
   Design Tokens — Dark
   ============================================================ */
[data-theme="dark"]{
  --bg: #0d0d0f;
  --surface: #1c1c1e;
  --ink: #f5f5f7;
  --ink-2: #a1a1a6;
  --muted: #86868b;
  --line: #2c2c2e;
  --accent: #2997ff;
  --accent-hover: #40a9ff;
  --accent-soft: rgba(41,151,255,.12);
  --shadow: 0 2px 8px rgba(0,0,0,.2), 0 0 0 1px rgba(255,255,255,.04);
  --shadow-hover: 0 8px 30px rgba(0,0,0,.3), 0 0 0 1px rgba(255,255,255,.06);
}

/* ============================================================
   Reset
   ============================================================ */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  font-family:'Inter',-apple-system,BlinkMacSystemFont,'SF Pro Text','Segoe UI',Roboto,sans-serif;
  color:var(--ink);
  background:var(--bg);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  overflow-x:hidden;
  transition:background .35s var(--ease),color .35s var(--ease);
}
img{max-width:100%;height:auto;display:block}
a{color:var(--accent);text-decoration:none;transition:color .2s var(--ease)}
a:hover{color:var(--accent-hover)}

/* ============================================================
   Typography
   ============================================================ */
h1,h2,h3,h4{
  font-weight:700;
  letter-spacing:-.02em;
  line-height:1.2;
  color:var(--ink);
  margin:0 0 .5em;
}
h1{font-size:clamp(2rem,2.5vw + 1rem,3rem);font-weight:700;letter-spacing:-.03em}
h2{font-size:clamp(1.4rem,1.5vw + .8rem,2rem);margin-top:2.5rem}
h3{font-size:clamp(1.1rem,.5vw + .9rem,1.3rem);margin-top:2rem}
h4{font-size:1rem}
p{margin:0 0 1.2rem;color:var(--ink-2);line-height:1.7}
ul,ol{margin:0 0 1.2rem;padding-left:1.25rem}
li{margin:.35rem 0;color:var(--ink-2)}

.container{max-width:1080px;margin:0 auto;padding:0 1.5rem}
.narrow{max-width:720px;margin:0 auto;padding:0 1.5rem}

/* ============================================================
   Header
   ============================================================ */
.site-header{
  position:sticky;top:0;z-index:100;
  background:rgba(251,251,253,.85);
  -webkit-backdrop-filter:saturate(180%) blur(20px);
  backdrop-filter:saturate(180%) blur(20px);
  border-bottom:1px solid var(--line);
  transition:box-shadow .3s var(--ease),background .35s var(--ease);
}
[data-theme="dark"] .site-header{
  background:rgba(13,13,15,.85);
}
.site-header.scrolled{
  box-shadow:0 1px 4px rgba(0,0,0,.06);
}
[data-theme="dark"] .site-header.scrolled{
  box-shadow:0 1px 8px rgba(0,0,0,.3);
}
.site-header .inner{
  display:flex;align-items:center;justify-content:space-between;
  max-width:1080px;margin:0 auto;padding:.75rem 1.5rem;
  gap:.5rem;
}
.brand{
  font-weight:700;font-size:1.1rem;letter-spacing:-.01em;
  color:var(--ink);flex-shrink:0;
}
.brand span{color:var(--accent)}
.nav{display:flex;gap:.15rem;align-items:center;font-size:.88rem;font-weight:500}
.nav a{
  color:var(--ink-2);padding:.5rem .7rem;border-radius:8px;
  transition:background .2s var(--ease),color .2s var(--ease);
}
.nav a:hover{background:var(--accent-soft);color:var(--accent)}

/* Dark mode toggle in header */
.theme-toggle{
  background:none;border:1px solid var(--line);
  border-radius:8px;padding:.4rem .55rem;cursor:pointer;
  font-size:1rem;color:var(--ink);
  display:inline-flex;align-items:center;justify-content:center;
  transition:background .2s var(--ease),border-color .2s var(--ease),transform .2s var(--spring);
  flex-shrink:0;
  width:36px;height:36px;
}
.theme-toggle:hover{background:var(--accent-soft);border-color:var(--accent);transform:scale(1.08)}
.theme-toggle:active{transform:scale(.95)}
.theme-toggle .icon-sun,
.theme-toggle .icon-moon{transition:opacity .2s,transform .3s var(--spring)}
[data-theme="dark"] .theme-toggle .icon-sun{opacity:1;transform:rotate(0deg)}
[data-theme="dark"] .theme-toggle .icon-moon{opacity:0;transform:rotate(-90deg);position:absolute}
.theme-toggle .icon-sun{opacity:0;transform:rotate(90deg);position:absolute}
.theme-toggle .icon-moon{opacity:1;transform:rotate(0deg)}

.menu-toggle{
  display:none;background:none;border:1px solid var(--line);
  border-radius:8px;padding:.45rem .6rem;cursor:pointer;font-size:1rem;
  color:var(--ink);flex-shrink:0;
  transition:background .2s var(--ease);
}
.menu-toggle:hover{background:var(--accent-soft)}

.header-actions{display:flex;align-items:center;gap:.5rem}

/* ============================================================
   Mobile Nav
   ============================================================ */
@media (max-width:768px){
  .site-header .inner{padding:.65rem 1rem}
  .nav{
    position:absolute;top:100%;left:0;right:0;
    background:rgba(251,251,253,.98);
    -webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);
    border-bottom:1px solid var(--line);
    flex-direction:column;align-items:stretch;
    padding:1rem 1.25rem;gap:.15rem;
    transform:translateY(-8px);opacity:0;
    pointer-events:none;
    transition:transform .3s var(--ease),opacity .3s var(--ease);
  }
  [data-theme="dark"] .nav{background:rgba(13,13,15,.98)}
  .nav.open{
    transform:translateY(0);opacity:1;
    pointer-events:all;
  }
  .nav a{padding:.75rem .7rem;font-size:.95rem}
  .menu-toggle{display:inline-flex;align-items:center}
}

/* ============================================================
   Hero
   ============================================================ */
.hero{
  padding:clamp(3rem,6vw,5rem) 1.5rem clamp(2.5rem,5vw,4.5rem);
  text-align:center;
  background:var(--surface);
  border-bottom:1px solid var(--line);
  transition:background .35s var(--ease);
}
.hero .container{max-width:680px}
.hero .overline{
  display:inline-block;
  font-size:.75rem;font-weight:600;letter-spacing:.06em;
  text-transform:uppercase;color:var(--accent);
  margin-bottom:1rem;
  animation:fadeInDown .6s var(--ease) both;
}
.hero h1{
  margin-bottom:1.25rem;
  animation:fadeInUp .7s var(--ease) .1s both;
}
.hero p{
  color:var(--muted);font-size:clamp(.95rem,1.5vw,.1.05rem);line-height:1.7;
  max-width:560px;margin:0 auto 2rem;
  animation:fadeInUp .7s var(--ease) .2s both;
}
.hero .cta-row{
  display:flex;gap:.75rem;justify-content:center;flex-wrap:wrap;
  animation:fadeInUp .7s var(--ease) .3s both;
}
.cta-primary{
  display:inline-flex;align-items:center;gap:.4rem;
  padding:.75rem 1.5rem;border-radius:980px;
  font-weight:600;font-size:.95rem;
  background:var(--accent);color:#fff;
  transition:background .2s var(--ease),transform .2s var(--spring),box-shadow .2s var(--ease);
}
.cta-primary:hover{
  background:var(--accent-hover);color:#fff;text-decoration:none;
  transform:translateY(-2px) scale(1.02);
  box-shadow:0 4px 16px rgba(0,113,227,.3);
}
.cta-primary:active{transform:scale(.98)}
.cta-secondary{
  display:inline-flex;align-items:center;gap:.4rem;
  padding:.75rem 1.5rem;border-radius:980px;
  font-weight:600;font-size:.95rem;
  color:var(--accent);background:transparent;
  transition:background .2s var(--ease),transform .2s var(--spring);
}
.cta-secondary:hover{background:var(--accent-soft);text-decoration:none;transform:translateY(-1px)}

/* Keep old class names working */
.hero .cta{
  display:inline-flex;align-items:center;gap:.4rem;
  padding:.75rem 1.5rem;border-radius:980px;
  font-weight:600;font-size:.95rem;
  background:var(--accent);color:#fff;
  transition:background .2s var(--ease),transform .2s var(--spring);
}
.hero .cta:hover{background:var(--accent-hover);color:#fff;text-decoration:none;transform:translateY(-2px)}
.hero .cta-ghost{
  display:inline-flex;align-items:center;gap:.4rem;
  padding:.75rem 1.5rem;border-radius:980px;
  font-weight:600;font-size:.95rem;
  color:var(--accent);background:transparent;
  transition:background .2s var(--ease);
}
.hero .cta-ghost:hover{background:var(--accent-soft);text-decoration:none;color:var(--accent)}

/* Eyebrow / stats */
.hero .eyebrow{
  display:inline-block;font-size:.75rem;font-weight:600;letter-spacing:.06em;
  text-transform:uppercase;color:var(--accent);margin-bottom:1rem;
}
.hero .eyebrow::before{display:none}
.hero .stats{display:flex;gap:2rem;justify-content:center;margin-top:3rem;flex-wrap:wrap}
.hero .stats .stat{text-align:center}
.hero .stats .num{font-size:1.5rem;font-weight:700;color:var(--ink)}
.hero .stats .lbl{font-size:.78rem;color:var(--muted);margin-top:.15rem}

@media (max-width:480px){
  .hero{padding:2.5rem 1rem 2rem}
  .hero h1{font-size:1.75rem}
  .hero p{font-size:.92rem}
  .hero .cta-row{flex-direction:column;align-items:center}
  .cta-primary,.cta-secondary,.hero .cta,.hero .cta-ghost{
    width:100%;max-width:280px;justify-content:center;
  }
  .hero .stats{gap:1.25rem}
  .hero .stats .num{font-size:1.25rem}
}

/* ============================================================
   Calculator Card
   ============================================================ */
.calc{
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:var(--r-xl);
  padding:clamp(1.25rem,2vw + .75rem,2.5rem);
  margin:2rem auto;
  box-shadow:var(--shadow);
  transition:background .35s var(--ease),border-color .35s var(--ease),box-shadow .35s var(--ease);
}
.calc::before{display:none}
.calc-grid{display:grid;grid-template-columns:1fr;gap:2rem}
@media (min-width:860px){.calc-grid{grid-template-columns:1fr 1fr;gap:3rem}}

/* ---------- Form fields ---------- */
.field{margin-bottom:1.75rem}
.field label{
  display:flex;justify-content:space-between;align-items:center;
  font-weight:600;font-size:.87rem;margin-bottom:.6rem;
  color:var(--ink);
}
.field label .val{
  background:var(--accent-soft);
  color:var(--accent);
  padding:.25rem .65rem;border-radius:6px;
  font-variant-numeric:tabular-nums;
  font-weight:700;font-size:.82rem;
  transition:transform .15s var(--spring);
}
.field label .val.pop{animation:pop .3s var(--spring)}
.field input[type=number],.field input[type=text],.field select{
  width:100%;padding:.8rem 1rem;
  border:1px solid var(--line);
  border-radius:var(--r);font-size:.95rem;
  background:var(--bg);
  color:var(--ink);
  font-variant-numeric:tabular-nums;font-weight:500;
  transition:border-color .2s var(--ease),box-shadow .2s var(--ease),background .35s var(--ease);
}
.field input[type=number]:focus,.field input[type=text]:focus,.field select:focus{
  outline:none;border-color:var(--accent);
  box-shadow:0 0 0 3px rgba(0,113,227,.12);
}

/* Range slider */
.field input[type=range]{
  width:100%;
  -webkit-appearance:none;appearance:none;
  height:4px;border-radius:999px;
  background:linear-gradient(to right,var(--accent) var(--pct,50%),var(--line) var(--pct,50%));
  outline:none;margin:.5rem 0;
  transition:background .35s var(--ease);
}
.field input[type=range]::-webkit-slider-thumb{
  -webkit-appearance:none;appearance:none;
  width:20px;height:20px;border-radius:50%;
  background:var(--surface);border:2px solid var(--accent);
  box-shadow:0 1px 4px rgba(0,0,0,.12);
  cursor:pointer;transition:transform .15s var(--spring),box-shadow .2s var(--ease);
}
.field input[type=range]::-webkit-slider-thumb:hover{transform:scale(1.15);box-shadow:0 2px 8px rgba(0,113,227,.25)}
.field input[type=range]::-webkit-slider-thumb:active{transform:scale(1.05)}
.field input[type=range]::-moz-range-thumb{
  width:18px;height:18px;border-radius:50%;
  background:var(--surface);border:2px solid var(--accent);
  box-shadow:0 1px 4px rgba(0,0,0,.12);
  cursor:pointer;
}
.row{display:grid;grid-template-columns:1fr 1fr;gap:.75rem}

@media (max-width:480px){
  .row{grid-template-columns:1fr;gap:.5rem}
  .field{margin-bottom:1.25rem}
  .field input[type=number],.field input[type=text],.field select{padding:.7rem .85rem;font-size:.92rem}
}

/* Toggle switch */
.toggle{
  display:flex;align-items:center;gap:.6rem;
  font-size:.9rem;font-weight:500;color:var(--ink-2);
  margin:.75rem 0;padding:.5rem .5rem;
  border-radius:8px;cursor:pointer;
  transition:background .2s var(--ease);
  user-select:none;
}
.toggle:hover{background:rgba(128,128,128,.06)}
.toggle input{
  appearance:none;-webkit-appearance:none;
  width:36px;height:20px;border-radius:999px;
  background:var(--line);position:relative;cursor:pointer;
  transition:background .2s var(--ease);flex-shrink:0;
}
.toggle input::after{
  content:'';position:absolute;top:2px;left:2px;
  width:16px;height:16px;border-radius:50%;background:#fff;
  box-shadow:0 1px 3px rgba(0,0,0,.18);
  transition:transform .2s var(--spring);
}
.toggle input:checked{background:var(--green)}
.toggle input:checked::after{transform:translateX(16px)}

/* ============================================================
   Results Panel
   ============================================================ */
.results{
  background:var(--bg);
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  padding:1.25rem 1.5rem;
  margin-top:.5rem;
  transition:background .35s var(--ease),border-color .35s var(--ease);
}
.result-row{
  display:flex;justify-content:space-between;align-items:center;
  padding:.75rem 0;
  border-bottom:1px solid var(--line);
}
.result-row:last-child{border-bottom:none}
.result-row .label{color:var(--muted);font-size:.88rem;font-weight:500}
.result-row .value{
  font-weight:700;font-size:1rem;
  font-variant-numeric:tabular-nums;
  color:var(--ink);
  transition:color .15s var(--ease);
}
.result-row.final{
  background:var(--ink);
  color:#fff;
  border:none;border-radius:var(--r);
  margin:.75rem -.5rem -.5rem;
  padding:1rem 1.25rem;
  transition:background .35s var(--ease),transform .25s var(--spring);
}
.result-row.final:hover{transform:scale(1.01)}
.result-row.final::before{display:none}
.result-row.final .label{color:rgba(255,255,255,.7);font-weight:500}
.result-row.final .value{color:#fff;font-size:1.2rem;font-weight:700}

[data-theme="dark"] .result-row.final{
  background:var(--accent);
}
[data-theme="dark"] .result-row.final .label{color:rgba(255,255,255,.8)}

.chart-wrap{
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  padding:1.25rem;margin-top:1rem;
  transition:background .35s var(--ease),border-color .35s var(--ease);
}

@media (max-width:480px){
  .results{padding:1rem}
  .result-row .label{font-size:.82rem}
  .result-row .value{font-size:.92rem}
  .result-row.final{padding:.85rem 1rem;margin:.5rem -.35rem -.35rem}
  .result-row.final .value{font-size:1.05rem}
}

/* ============================================================
   Content / Prose
   ============================================================ */
.content{
  background:var(--surface);
  border-top:1px solid var(--line);
  padding:clamp(2.5rem,4vw,4rem) 1.5rem clamp(3rem,5vw,5rem);
  margin-top:2rem;
  transition:background .35s var(--ease);
}
.content::before{display:none}
.content p,.content li{color:var(--ink-2)}
blockquote{
  border-left:3px solid var(--accent);
  background:var(--accent-soft);
  margin:1.5rem 0;padding:1rem 1.25rem;
  color:var(--ink-2);border-radius:0 var(--r) var(--r) 0;
  font-style:italic;
}
table{
  width:100%;border-collapse:collapse;margin:1.5rem 0;
  font-size:.9rem;font-variant-numeric:tabular-nums;
  background:var(--surface);border-radius:var(--r);overflow:hidden;
  border:1px solid var(--line);
}
th,td{padding:.75rem 1rem;border-bottom:1px solid var(--line);text-align:left}
th{background:var(--bg);font-weight:600;color:var(--ink);font-size:.85rem;text-transform:uppercase;letter-spacing:.02em}
tr:last-child td{border-bottom:none}

/* Responsive tables */
@media (max-width:640px){
  table{font-size:.82rem}
  th,td{padding:.55rem .65rem}
  .content{padding:2rem 1rem 2.5rem}
}

/* ============================================================
   Calculator Grid (Homepage)
   ============================================================ */
.cgrid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(240px,1fr));
  gap:1rem;margin:1.5rem 0 3rem;
}
.cgrid a{
  display:flex;align-items:flex-start;gap:1rem;
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  padding:1.25rem 1.15rem;
  color:var(--ink);
  transition:box-shadow .3s var(--ease),border-color .3s var(--ease),transform .3s var(--spring),background .35s var(--ease);
}
.cgrid a::before,.cgrid a::after{display:none}
.cgrid a:hover{
  box-shadow:var(--shadow-hover);
  border-color:transparent;
  text-decoration:none;
  transform:translateY(-4px);
}
.cgrid a:active{transform:translateY(0) scale(.98)}
.cgrid .ic{
  font-size:1.5rem;
  display:inline-flex;align-items:center;justify-content:center;
  width:44px;height:44px;border-radius:var(--r);flex-shrink:0;
  background:var(--bg);
  transition:background .35s var(--ease),transform .3s var(--spring);
}
.cgrid a:hover .ic{transform:scale(1.1) rotate(-3deg)}
.cgrid strong{
  display:block;font-size:.95rem;font-weight:600;margin-bottom:.15rem;
  color:var(--ink);
}
.cgrid span{color:var(--muted);font-size:.82rem;display:block;line-height:1.4}

@media (max-width:540px){
  .cgrid{grid-template-columns:1fr;gap:.75rem}
  .cgrid a{padding:1rem}
}
@media (min-width:541px) and (max-width:768px){
  .cgrid{grid-template-columns:repeat(2,1fr);gap:.75rem}
}

/* Section labels */
.section-pill{
  display:inline-block;padding:.3rem .75rem;border-radius:980px;
  background:var(--accent-soft);color:var(--accent);
  font-size:.72rem;font-weight:600;letter-spacing:.04em;
  text-transform:uppercase;
}

/* ============================================================
   FAQ Accordion
   ============================================================ */
details{
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:var(--r);
  padding:1rem 1.25rem;
  margin:.55rem 0;
  transition:box-shadow .2s var(--ease),background .35s var(--ease),border-color .35s var(--ease);
}
details[open]{box-shadow:var(--shadow)}
details summary{
  font-weight:600;cursor:pointer;color:var(--ink);list-style:none;
  display:flex;justify-content:space-between;align-items:center;gap:1rem;
  font-size:.95rem;
}
details summary::-webkit-details-marker{display:none}
details summary::after{
  content:'+';font-size:1.3rem;font-weight:300;color:var(--muted);
  transition:transform .3s var(--spring),color .2s var(--ease);flex-shrink:0;
}
details[open] summary::after{transform:rotate(45deg);color:var(--accent)}
details p{margin:.65rem 0 0;color:var(--muted);line-height:1.7;font-size:.92rem}

@media (max-width:480px){
  details{padding:.85rem 1rem}
  details summary{font-size:.9rem;gap:.5rem}
}

/* ============================================================
   Ad Slot
   ============================================================ */
.ad-slot{
  background:var(--bg);
  border:1px dashed var(--line);
  text-align:center;padding:1rem;
  color:var(--muted);font-size:.75rem;
  margin:2rem 0;border-radius:var(--r);
  font-weight:500;letter-spacing:.05em;text-transform:uppercase;
  transition:background .35s var(--ease),border-color .35s var(--ease);
}

/* ============================================================
   Footer
   ============================================================ */
.site-footer{
  background:var(--ink);
  color:#86868b;
  padding:3.5rem 1.5rem 2rem;
  margin-top:3rem;
  transition:background .35s var(--ease);
}
[data-theme="dark"] .site-footer{background:#000}
.site-footer::before{display:none}
.site-footer .fgrid{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));
  gap:2rem;max-width:1080px;margin:0 auto;
}
.site-footer h4{
  color:#f5f5f7;margin-bottom:.75rem;font-size:.85rem;
  font-weight:600;letter-spacing:.02em;text-transform:uppercase;
}
.site-footer a{
  color:#86868b;display:block;padding:.25rem 0;font-size:.88rem;
  transition:color .2s var(--ease);
}
.site-footer a:hover{color:#f5f5f7;text-decoration:none}
.site-footer .copy{
  text-align:center;margin-top:2.5rem;padding-top:1.5rem;
  border-top:1px solid rgba(255,255,255,.08);
  font-size:.8rem;color:#6e6e73;
}
.site-footer .copy a{display:inline;padding:0 .25rem;color:#86868b}

@media (max-width:480px){
  .site-footer{padding:2.5rem 1rem 1.5rem}
  .site-footer .fgrid{grid-template-columns:1fr 1fr;gap:1.25rem}
  .site-footer h4{font-size:.8rem}
  .site-footer a{font-size:.82rem;padding:.2rem 0}
}

/* ============================================================
   Breadcrumb, Misc
   ============================================================ */
.muted{color:var(--muted);font-size:.9rem}
.badge{
  display:inline-block;
  background:var(--accent-soft);color:var(--accent);
  padding:.2rem .55rem;border-radius:5px;
  font-size:.7rem;font-weight:600;letter-spacing:.03em;
  text-transform:uppercase;
}
.btn{
  display:inline-flex;align-items:center;gap:.4rem;
  background:var(--accent);color:#fff;
  padding:.7rem 1.25rem;border-radius:980px;
  font-weight:600;border:none;cursor:pointer;font-size:.9rem;
  transition:background .2s var(--ease),transform .2s var(--spring);
}
.btn:hover{background:var(--accent-hover);text-decoration:none;color:#fff;transform:scale(1.02)}
.btn:active{transform:scale(.97)}
.breadcrumb{font-size:.82rem;color:var(--muted);margin:1rem 0}
.breadcrumb a{color:var(--muted)}
.breadcrumb a:hover{color:var(--accent)}

/* ============================================================
   Scroll Reveal Animations (multiple variants)
   ============================================================ */
.reveal{
  opacity:0;transform:translateY(24px);
  transition:opacity .6s var(--ease),transform .6s var(--ease);
}
.reveal.in{opacity:1;transform:translateY(0)}

.reveal-left{
  opacity:0;transform:translateX(-30px);
  transition:opacity .6s var(--ease),transform .6s var(--ease);
}
.reveal-left.in{opacity:1;transform:translateX(0)}

.reveal-right{
  opacity:0;transform:translateX(30px);
  transition:opacity .6s var(--ease),transform .6s var(--ease);
}
.reveal-right.in{opacity:1;transform:translateX(0)}

.reveal-scale{
  opacity:0;transform:scale(.92);
  transition:opacity .5s var(--ease),transform .5s var(--spring);
}
.reveal-scale.in{opacity:1;transform:scale(1)}

.reveal-fade{
  opacity:0;
  transition:opacity .6s var(--ease);
}
.reveal-fade.in{opacity:1}

/* Staggered children */
.stagger-children .reveal:nth-child(1){transition-delay:.05s}
.stagger-children .reveal:nth-child(2){transition-delay:.1s}
.stagger-children .reveal:nth-child(3){transition-delay:.15s}
.stagger-children .reveal:nth-child(4){transition-delay:.2s}
.stagger-children .reveal:nth-child(5){transition-delay:.25s}
.stagger-children .reveal:nth-child(6){transition-delay:.3s}
.stagger-children .reveal:nth-child(7){transition-delay:.35s}
.stagger-children .reveal:nth-child(8){transition-delay:.4s}

/* Stagger grid items */
.cgrid.stagger a:nth-child(1){transition-delay:.03s}
.cgrid.stagger a:nth-child(2){transition-delay:.06s}
.cgrid.stagger a:nth-child(3){transition-delay:.09s}
.cgrid.stagger a:nth-child(4){transition-delay:.12s}
.cgrid.stagger a:nth-child(5){transition-delay:.15s}
.cgrid.stagger a:nth-child(6){transition-delay:.18s}

/* ============================================================
   Keyframe Animations
   ============================================================ */
@keyframes fadeInUp{
  from{opacity:0;transform:translateY(20px)}
  to{opacity:1;transform:translateY(0)}
}
@keyframes fadeInDown{
  from{opacity:0;transform:translateY(-12px)}
  to{opacity:1;transform:translateY(0)}
}
@keyframes pop{
  0%{transform:scale(1)}
  50%{transform:scale(1.15)}
  100%{transform:scale(1)}
}
@keyframes slideIn{
  from{opacity:0;transform:translateX(-16px)}
  to{opacity:1;transform:translateX(0)}
}
@keyframes pulse{
  0%,100%{opacity:1}
  50%{opacity:.6}
}
@keyframes shimmer{
  0%{background-position:-200% 0}
  100%{background-position:200% 0}
}

/* Skeleton loading */
.skeleton{
  background:linear-gradient(90deg,var(--line) 25%,var(--bg) 50%,var(--line) 75%);
  background-size:200% 100%;
  animation:shimmer 1.5s infinite;
  border-radius:var(--r);
}

/* Float animation for hero elements */
@keyframes float{
  0%,100%{transform:translateY(0)}
  50%{transform:translateY(-6px)}
}
.float{animation:float 3s ease-in-out infinite}

/* ============================================================
   3D Animations & Effects
   ============================================================ */

/* 3D perspective container */
.perspective{perspective:1200px}

/* 3D card tilt (applied via JS mousemove) */
.tilt-3d{
  transform-style:preserve-3d;
  transition:transform .15s var(--ease),box-shadow .25s var(--ease);
  will-change:transform;
}
.tilt-3d:hover{
  box-shadow:0 20px 40px rgba(0,0,0,.12),0 0 0 1px rgba(0,0,0,.03);
}
[data-theme="dark"] .tilt-3d:hover{
  box-shadow:0 20px 40px rgba(0,0,0,.4),0 0 0 1px rgba(255,255,255,.05);
}
.tilt-3d .tilt-inner{
  transform:translateZ(20px);
  transition:transform .3s var(--ease);
}

/* 3D flip card */
.flip-card{
  perspective:800px;
  cursor:pointer;
}
.flip-card-inner{
  transform-style:preserve-3d;
  transition:transform .6s var(--spring);
}
.flip-card:hover .flip-card-inner{
  transform:rotateY(180deg);
}
.flip-card-front,.flip-card-back{
  backface-visibility:hidden;
}
.flip-card-back{
  transform:rotateY(180deg);
  position:absolute;inset:0;
}

/* 3D floating hero effect */
.hero-3d{
  perspective:1000px;
  overflow:visible;
}
.hero-3d h1{
  transform-style:preserve-3d;
  animation:hero3dFloat 6s ease-in-out infinite;
}
@keyframes hero3dFloat{
  0%,100%{transform:translateZ(0) rotateX(0deg)}
  25%{transform:translateZ(15px) rotateX(1.5deg)}
  50%{transform:translateZ(30px) rotateX(0deg)}
  75%{transform:translateZ(15px) rotateX(-1.5deg)}
}

/* 3D calculator card entrance */
.calc-3d-enter{
  animation:calc3dIn .8s var(--spring) both;
}
@keyframes calc3dIn{
  from{opacity:0;transform:perspective(800px) rotateX(8deg) translateY(30px) scale(.96)}
  to{opacity:1;transform:perspective(800px) rotateX(0) translateY(0) scale(1)}
}

/* 3D grid card hover with depth */
.cgrid a{
  transform-style:preserve-3d;
  perspective:600px;
}
.cgrid a:hover{
  transform:translateY(-4px) rotateX(-2deg) rotateY(1deg);
  box-shadow:0 16px 32px rgba(0,0,0,.1),0 2px 8px rgba(0,0,0,.06);
}
[data-theme="dark"] .cgrid a:hover{
  box-shadow:0 16px 32px rgba(0,0,0,.35),0 2px 8px rgba(0,0,0,.2);
}
.cgrid a:hover .ic{
  transform:scale(1.1) rotate(-3deg) translateZ(10px);
}

/* 3D result panel pop */
.result-row.final{
  transform-style:preserve-3d;
}
.result-row.final:hover{
  transform:scale(1.01) translateZ(5px);
}

/* 3D button press */
.cta-primary,.btn{
  transform-style:preserve-3d;
}
.cta-primary:active,.btn:active{
  transform:perspective(400px) rotateX(3deg) scale(.97);
}

/* 3D FAQ open */
details{
  transform-style:preserve-3d;
  transition:box-shadow .2s var(--ease),background .35s var(--ease),border-color .35s var(--ease),transform .3s var(--ease);
}
details[open]{
  box-shadow:var(--shadow);
  transform:perspective(600px) rotateX(-1deg);
}

/* Parallax scroll depth layers */
.parallax-slow{
  will-change:transform;
  transition:transform .1s linear;
}
.parallax-fast{
  will-change:transform;
  transition:transform .1s linear;
}

/* Glow effect on accent elements */
.glow{
  position:relative;
}
.glow::after{
  content:'';position:absolute;inset:-2px;
  border-radius:inherit;
  background:linear-gradient(135deg,var(--accent),#a855f7,var(--accent));
  background-size:200% 200%;
  animation:glowShift 3s ease-in-out infinite;
  opacity:0;z-index:-1;
  transition:opacity .3s var(--ease);
  filter:blur(12px);
}
.glow:hover::after{opacity:.4}
[data-theme="dark"] .glow:hover::after{opacity:.6}

@keyframes glowShift{
  0%,100%{background-position:0% 50%}
  50%{background-position:100% 50%}
}

/* 3D reveal animations */
.reveal-3d{
  opacity:0;
  transform:perspective(800px) rotateY(-8deg) translateX(-20px);
  transition:opacity .6s var(--ease),transform .7s var(--spring);
}
.reveal-3d.in{
  opacity:1;
  transform:perspective(800px) rotateY(0) translateX(0);
}

.reveal-3d-up{
  opacity:0;
  transform:perspective(800px) rotateX(6deg) translateY(30px);
  transition:opacity .6s var(--ease),transform .7s var(--spring);
}
.reveal-3d-up.in{
  opacity:1;
  transform:perspective(800px) rotateX(0) translateY(0);
}

/* Magnetic hover for buttons */
.magnetic{
  transition:transform .2s var(--ease);
}

/* Glass morphism card variant */
.glass{
  background:rgba(255,255,255,.6);
  -webkit-backdrop-filter:blur(16px);
  backdrop-filter:blur(16px);
  border:1px solid rgba(255,255,255,.3);
}
[data-theme="dark"] .glass{
  background:rgba(28,28,30,.6);
  border:1px solid rgba(255,255,255,.08);
}

/* Related Calculators section */
.related-calcs{
  padding:3rem 0;
  border-top:1px solid var(--line);
  margin-top:2rem;
}
.related-calcs h2{margin-top:0}
.related-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(200px,1fr));
  gap:.75rem;
  margin-top:1rem;
}
.related-grid a{
  display:flex;align-items:center;gap:.6rem;
  padding:.85rem 1rem;
  border:1px solid var(--line);
  border-radius:var(--r);
  font-size:.88rem;font-weight:500;
  color:var(--ink);
  background:var(--surface);
  transition:all .25s var(--ease);
  transform-style:preserve-3d;
}
.related-grid a:hover{
  border-color:var(--accent);
  background:var(--accent-soft);
  color:var(--accent);
  transform:translateY(-2px) rotateX(-1deg);
  box-shadow:0 4px 12px rgba(0,113,227,.12);
  text-decoration:none;
}
.related-grid a .arrow{
  margin-left:auto;
  opacity:.3;
  transition:opacity .2s,transform .2s var(--spring);
}
.related-grid a:hover .arrow{opacity:1;transform:translateX(3px)}

@media (max-width:480px){
  .related-grid{grid-template-columns:1fr}
}

/* ============================================================
   Reduced Motion
   ============================================================ */
@media (prefers-reduced-motion:reduce){
  *{animation-duration:.01ms !important;animation-iteration-count:1 !important;transition-duration:.01ms !important}
  .reveal,.reveal-left,.reveal-right,.reveal-scale,.reveal-fade{opacity:1;transform:none;transition:none}
}

/* ============================================================
   Scrollbar (Dark mode)
   ============================================================ */
[data-theme="dark"]::-webkit-scrollbar{width:8px}
[data-theme="dark"]::-webkit-scrollbar-track{background:var(--bg)}
[data-theme="dark"]::-webkit-scrollbar-thumb{background:var(--line);border-radius:4px}

/* ============================================================
   Print
   ============================================================ */
@media print{
  .site-header,.site-footer,.ad-slot,.theme-toggle,.menu-toggle{display:none!important}
  body{background:#fff;color:#000}
  .calc{box-shadow:none;border:1px solid #ccc}
}