/* ==========================================================================
   Design Asylum — Calculators
   base.css : design tokens, reset, shared primitives
   Brand system mirrors the Fuel Calculator (dark + orange, Anton + Inter).
   ========================================================================== */

:root{
  /* palette */
  --bg:#0A0A0B;
  --bg-2:#0E0E10;
  --panel:#141416;
  --panel-2:#1B1B1F;
  --border:#2C2C33;
  --border-soft:#232328;
  --accent:#FF6A1F;
  --accent-soft:#FFB066;
  --ink:#F7F7F9;
  --muted:#B4B4BC;
  --muted-2:#8C8C95;

  /* shape */
  --radius:16px;
  --radius-lg:22px;
  --tap:44px;

  /* elevation */
  --shadow-sm:0 1px 2px rgba(0,0,0,.4);
  --shadow-xl:0 24px 60px -12px rgba(0,0,0,.75), 0 0 0 1px rgba(255,106,31,.12);

  /* motion */
  --ease:cubic-bezier(.22,.61,.36,1);

  /* fluid layout */
  --page-max:1440px;
  --gutter:clamp(20px, 4vw, 56px);
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
html,body{margin:0;padding:0}

body{
  background:var(--bg);
  color:var(--ink);
  font-family:Inter,system-ui,-apple-system,Segoe UI,Arial,sans-serif;
  font-size:16px;
  line-height:1.5;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  min-height:100vh;
  display:flex;
  flex-direction:column;
}

img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font:inherit}

/* subtle brand ambience behind everything */
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:-1;
  background:
    radial-gradient(60vw 40vw at 85% -10%, rgba(255,106,31,.10), transparent 60%),
    radial-gradient(50vw 40vw at -10% 0%, rgba(255,176,102,.05), transparent 55%);
  pointer-events:none;
}

/* ---- layout container ---- */
.container{
  width:100%;
  max-width:var(--page-max);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

/* ==========================================================================
   Brand wordmark (nav logo)
   ========================================================================== */
.brand{display:inline-flex;align-items:center}
.brand__logo{height:clamp(30px,3.2vw,40px);width:auto;display:block}

/* ==========================================================================
   Top navigation (shared by homepage + calculator pages)
   ========================================================================== */
.nav{
  position:sticky;top:0;z-index:20;
  background:rgba(10,10,11,.72);
  backdrop-filter:saturate(140%) blur(12px);
  -webkit-backdrop-filter:saturate(140%) blur(12px);
  border-bottom:1px solid var(--border-soft);
}
.nav__inner{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  min-height:72px;padding-block:12px;
}
.nav__left{display:flex;align-items:center;gap:clamp(14px,3vw,28px);min-width:0}
.nav__back{
  display:inline-flex;align-items:center;gap:7px;
  font-size:13.5px;font-weight:500;color:var(--muted);
  padding:8px 4px;border-radius:8px;transition:color .18s var(--ease);
}
.nav__back:hover{color:var(--ink)}
.nav__back svg{width:15px;height:15px}

/* primary button (Visit website) */
.btn{
  display:inline-flex;align-items:center;gap:9px;
  font-size:14px;font-weight:600;
  padding:0 18px;min-height:var(--tap);
  border-radius:11px;border:1px solid transparent;
  cursor:pointer;white-space:nowrap;
  transition:transform .18s var(--ease), background .18s var(--ease), border-color .18s var(--ease);
}
.btn--primary{background:var(--accent);color:#0A0A0B}
.btn--primary:hover{background:#ff7d3c;transform:translateY(-1px)}
.btn--ghost{background:var(--panel-2);border-color:var(--border);color:var(--muted)}
.btn--ghost:hover{color:var(--ink);border-color:var(--accent)}
.btn svg{width:16px;height:16px}
.btn:focus-visible,.nav__back:focus-visible,a:focus-visible{
  outline:2px solid var(--accent);outline-offset:3px;border-radius:8px;
}
/* hide the button label on very small screens, keep the icon */
@media(max-width:560px){
  .btn--primary .btn__label{
    position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);
  }
  .btn--primary{padding:0 14px}
}

/* ==========================================================================
   Footer (shared) — exact required copy
   ========================================================================== */
.site-footer{
  margin-top:auto;
  border-top:1px solid var(--border-soft);
  padding-block:26px;
}
.site-footer__inner{
  display:flex;align-items:center;justify-content:center;
  gap:10px;text-align:center;
}
.site-footer p{
  margin:0;color:var(--muted-2);
  font-size:13px;letter-spacing:.01em;
}

/* accessibility helper */
.visually-hidden{
  position:absolute!important;width:1px;height:1px;
  padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.001ms!important;transition-duration:.001ms!important;
  }
}