/* ============================================================
   CalcHub — Linear-inspired dark theme
   Design tokens lifted from DESIGN-linear.app.md
   ============================================================ */

@import url('https://rsms.me/inter/inter.css');
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500&display=swap');

:root{
  /* Surfaces (dark stack) */
  --bg-marketing:#08090a;
  --bg-panel:#0f1011;
  --bg-surface:#191a1b;
  --bg-secondary:#28282c;

  /* Text */
  --t-primary:#f7f8f8;
  --t-secondary:#d0d6e0;
  --t-tertiary:#8a8f98;
  --t-quaternary:#62666d;

  /* Brand */
  --brand:#5e6ad2;
  --accent:#7170ff;
  --accent-hover:#828fff;

  /* Status */
  --success:#10b981;
  --success-deep:#27a644;

  /* Borders */
  --border-subtle:rgba(255,255,255,0.05);
  --border-std:rgba(255,255,255,0.08);
  --border-solid:#23252a;

  /* Surface fills (translucent) */
  --fill-1:rgba(255,255,255,0.02);
  --fill-2:rgba(255,255,255,0.04);
  --fill-3:rgba(255,255,255,0.05);

  /* Radii */
  --r-2:2px; --r-4:4px; --r-6:6px; --r-8:8px; --r-12:12px; --r-22:22px;

  /* Shadows */
  --shadow-elevated:rgba(0,0,0,0.4) 0px 2px 4px;
  --shadow-dialog: 0 8px 2px rgba(0,0,0,0), 0 5px 2px rgba(0,0,0,0.01),
                   0 3px 2px rgba(0,0,0,0.04), 0 1px 1px rgba(0,0,0,0.07),
                   0 0 0 1px rgba(255,255,255,0.06);
  --shadow-focus:  0 0 0 3px rgba(113,112,255,0.25);

  /* Layout */
  --container:1120px;
}

/* -------------------- Reset & base -------------------- */
*,*::before,*::after{box-sizing:border-box}
html,body{margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;color-scheme:dark}
body{
  background:var(--bg-marketing);
  color:var(--t-primary);
  font-family:'Inter var','Inter','SF Pro Display',-apple-system,system-ui,'Segoe UI',Roboto,sans-serif;
  font-feature-settings:'cv01','ss03';
  font-weight:400;
  font-size:16px;
  line-height:1.5;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  min-height:100vh;
}
@supports (font-variation-settings:normal){
  body{font-family:'Inter var','SF Pro Display',-apple-system,system-ui,sans-serif}
}

/* Subtle ambient gradient on the marketing background */
body::before{
  content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  background:
    radial-gradient(900px 500px at 20% -10%, rgba(94,106,210,0.10), transparent 60%),
    radial-gradient(700px 400px at 100% 0%, rgba(113,112,255,0.06), transparent 60%);
}

a{color:var(--accent);text-decoration:none;transition:color .15s ease}
a:hover{color:var(--accent-hover)}

::selection{background:rgba(113,112,255,0.35);color:var(--t-primary)}

/* -------------------- Typography -------------------- */
h1,h2,h3,h4{color:var(--t-primary);margin:0 0 .5em;font-weight:510}
h1{font-size:clamp(2rem, 5vw + 1rem, 4rem);line-height:1.02;letter-spacing:-0.033em;font-weight:510}
h2{font-size:clamp(1.5rem, 2vw + 1rem, 2.25rem);line-height:1.1;letter-spacing:-0.022em;font-weight:510;margin-top:1.6em}
h3{font-size:1.25rem;line-height:1.33;letter-spacing:-0.012em;font-weight:590}
p{margin:.6em 0;color:var(--t-secondary)}
.lead{font-size:1.125rem;line-height:1.6;color:var(--t-tertiary);letter-spacing:-0.009em;max-width:62ch}
small,.muted{color:var(--t-tertiary);font-size:.875rem}
ul{color:var(--t-secondary)}
li{margin:.25em 0}
code,kbd,pre,.mono{
  font-family:'JetBrains Mono','Berkeley Mono',ui-monospace,'SF Mono',Menlo,monospace;
  font-size:.85em;
}

/* -------------------- Layout -------------------- */
.container{max-width:var(--container);margin:0 auto;padding:0 24px}
@media (max-width:600px){.container{padding:0 16px}}
main{padding:32px 0 64px}

/* -------------------- Header -------------------- */
header{
  position:sticky;top:0;z-index:50;
  background:rgba(15,16,17,0.72);
  backdrop-filter:saturate(140%) blur(12px);
  -webkit-backdrop-filter:saturate(140%) blur(12px);
  border-bottom:1px solid var(--border-subtle);
}
header .container{display:flex;align-items:center;justify-content:space-between;height:60px;gap:16px}
.logo{display:inline-flex;align-items:center;gap:8px;font-weight:590;font-size:.95rem;color:var(--t-primary);letter-spacing:-0.01em}
.logo-mark{
  width:22px;height:22px;border-radius:6px;
  background:linear-gradient(135deg,var(--brand),var(--accent));
  display:inline-grid;place-items:center;color:#fff;font-size:12px;font-weight:590;
  box-shadow:inset 0 0 0 1px rgba(255,255,255,0.12), 0 1px 2px rgba(0,0,0,0.5);
}
header nav{display:flex;align-items:center;gap:6px}
header nav a{
  color:var(--t-secondary);font-size:.875rem;font-weight:510;
  padding:6px 10px;border-radius:var(--r-6);transition:background .15s ease,color .15s ease;
}
header nav a:hover{color:var(--t-primary);background:var(--fill-2)}
header nav .cta{
  background:var(--brand);color:#fff;padding:7px 14px;border-radius:var(--r-6);
  border:1px solid rgba(255,255,255,0.12);
  box-shadow:inset 0 1px 0 rgba(255,255,255,0.10), 0 1px 2px rgba(0,0,0,0.4);
}
header nav .cta:hover{background:var(--accent-hover);color:#fff}
@media (max-width:640px){
  header nav a:not(.cta){display:none}
}

/* -------------------- Hero (homepage) -------------------- */
.hero{padding:72px 0 48px;text-align:center;position:relative}
.hero .eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-size:.75rem;font-weight:510;letter-spacing:-0.005em;
  color:var(--t-secondary);
  background:var(--fill-2);
  border:1px solid var(--border-std);
  border-radius:9999px;
  padding:5px 12px 5px 6px;
  margin-bottom:22px;
}
.hero .eyebrow .dot{width:6px;height:6px;border-radius:50%;background:var(--success);box-shadow:0 0 8px rgba(16,185,129,0.6)}
.hero h1{margin:.1em auto .3em;max-width:14ch}
.hero .lead{margin:0 auto;font-size:1.125rem;color:var(--t-tertiary)}
.hero .actions{display:flex;gap:12px;justify-content:center;margin-top:28px;flex-wrap:wrap}

/* -------------------- Buttons -------------------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  font:inherit;font-weight:510;font-size:.875rem;
  padding:9px 16px;border-radius:var(--r-6);
  border:1px solid var(--border-std);
  background:var(--fill-1);color:var(--t-primary);
  cursor:pointer;text-decoration:none;
  transition:background .15s ease,border-color .15s ease,transform .05s ease;
  letter-spacing:-0.005em;
}
.btn:hover{background:var(--fill-3);color:var(--t-primary);text-decoration:none}
.btn:active{transform:translateY(1px)}
.btn:focus-visible{outline:none;box-shadow:var(--shadow-focus)}
.btn-primary{
  background:var(--brand);color:#fff;
  border:1px solid rgba(255,255,255,0.12);
  box-shadow:inset 0 1px 0 rgba(255,255,255,0.10), 0 1px 2px rgba(0,0,0,0.4);
}
.btn-primary:hover{background:var(--accent-hover);color:#fff}

/* -------------------- Cards / grid -------------------- */
.grid{
  display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));
  gap:14px;margin:22px 0;
}
.card{
  display:block;padding:18px;
  background:var(--fill-1);
  border:1px solid var(--border-std);
  border-radius:var(--r-12);
  color:var(--t-primary);
  transition:background .15s ease,border-color .15s ease,transform .12s ease;
  position:relative;overflow:hidden;
}
.card:hover{
  background:var(--fill-2);
  border-color:rgba(255,255,255,0.14);
  text-decoration:none;
  transform:translateY(-2px);
}
.card .icon{
  width:32px;height:32px;border-radius:var(--r-8);
  background:var(--fill-3);border:1px solid var(--border-std);
  display:grid;place-items:center;margin-bottom:14px;font-size:14px;color:var(--accent);
}
.card .t{font-weight:590;font-size:1rem;letter-spacing:-0.012em;color:var(--t-primary)}
.card .d{color:var(--t-tertiary);font-size:.875rem;margin-top:4px;letter-spacing:-0.005em}

/* -------------------- Calculator panel -------------------- */
.calc{
  background:var(--fill-1);
  border:1px solid var(--border-std);
  border-radius:var(--r-12);
  padding:22px;margin:20px 0;
  box-shadow:inset 0 1px 0 rgba(255,255,255,0.03);
}
.calc label{
  display:block;font-weight:510;font-size:.8125rem;
  color:var(--t-secondary);margin:14px 0 6px;letter-spacing:-0.005em;
}
.calc input,.calc select{
  width:100%;padding:10px 12px;
  background:var(--fill-1);
  color:var(--t-primary);
  border:1px solid var(--border-std);
  border-radius:var(--r-6);
  font:inherit;font-size:.9375rem;
  transition:border-color .15s ease,box-shadow .15s ease,background .15s ease;
}
.calc input::placeholder{color:var(--t-quaternary)}
.calc input:hover,.calc select:hover{border-color:rgba(255,255,255,0.14)}
.calc input:focus,.calc select:focus{
  outline:none;border-color:var(--accent);
  background:var(--fill-2);
  box-shadow:var(--shadow-focus);
}
.calc select{appearance:none;-webkit-appearance:none;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'><path fill='%238a8f98' d='M6 8L2 4h8z'/></svg>");
  background-repeat:no-repeat;background-position:right 12px center;padding-right:36px;
  cursor:pointer;
}
.calc select option,
.calc select optgroup{
  background:#101113;
  color:var(--t-primary);
  padding:8px 12px;
  font-weight:510;
}
.calc select option:checked,
.calc select option:hover{
  background:linear-gradient(#5e6ad2,#5e6ad2);
  color:#fff;
}

/* Custom select (replaces native dropdown for consistent dark theme) */
.cs-wrap{position:relative;width:100%}
.cs-wrap > select{
  display:none !important;
}
.calc .cs-btn,
button.cs-btn{
  width:100%;margin-top:0;padding:10px 12px;
  background:var(--fill-1);color:var(--t-primary);
  border:1px solid var(--border-std);border-radius:var(--r-6);
  font:inherit;font-size:.9375rem;font-weight:510;
  display:flex;align-items:center;justify-content:space-between;gap:10px;
  cursor:pointer;text-align:left;letter-spacing:-0.005em;
  box-shadow:none;
  transition:border-color .15s ease,background .15s ease,box-shadow .15s ease;
}
.calc .cs-btn:hover,
button.cs-btn:hover{
  background:var(--fill-2);border-color:rgba(255,255,255,0.14);
  transform:none;
}
.calc .cs-btn[aria-expanded="true"],
.calc .cs-btn:focus-visible,
button.cs-btn[aria-expanded="true"],
button.cs-btn:focus-visible{
  outline:none;border-color:var(--accent);
  background:var(--fill-2);box-shadow:var(--shadow-focus);
}
.cs-label{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:var(--t-primary)}
.cs-caret{display:inline-flex;color:var(--t-tertiary);transition:transform .15s ease}
.cs-btn[aria-expanded="true"] .cs-caret{transform:rotate(180deg);color:var(--accent)}
.cs-list{
  position:absolute;left:0;right:0;top:calc(100% + 6px);
  margin:0;padding:6px;list-style:none;z-index:50;
  background:#101113;
  border:1px solid var(--border-std);border-radius:var(--r-8);
  box-shadow:0 12px 32px rgba(0,0,0,0.55), 0 2px 6px rgba(0,0,0,0.4);
  max-height:280px;overflow-y:auto;
  animation:csfade .12s ease-out;
}
@keyframes csfade{from{opacity:0;transform:translateY(-4px)}to{opacity:1;transform:none}}
.cs-opt{
  padding:9px 12px;border-radius:var(--r-4);
  color:var(--t-primary);font-size:.9375rem;font-weight:510;
  cursor:pointer;letter-spacing:-0.005em;
  display:flex;align-items:center;gap:8px;
  transition:background .1s ease,color .1s ease;
}
.cs-opt:hover{background:rgba(94,106,210,0.18);color:#fff}
.cs-opt[aria-selected="true"]{
  background:var(--brand);color:#fff;
}
.cs-opt[aria-selected="true"]::before{
  content:"";width:6px;height:6px;border-radius:50%;background:#fff;flex:none;
}
.cs-opt.cs-disabled{opacity:.45;cursor:not-allowed}
.cs-list::-webkit-scrollbar{width:8px}
.cs-list::-webkit-scrollbar-thumb{background:rgba(255,255,255,0.14);border-radius:4px}
.calc button{
  margin-top:18px;
  background:var(--brand);color:#fff;border:1px solid rgba(255,255,255,0.12);
  padding:10px 18px;font-size:.875rem;font-weight:510;
  border-radius:var(--r-6);cursor:pointer;letter-spacing:-0.005em;
  box-shadow:inset 0 1px 0 rgba(255,255,255,0.10), 0 1px 2px rgba(0,0,0,0.4);
  transition:background .15s ease,transform .05s ease;
}
.calc button:hover{background:var(--accent-hover)}
.calc button:active{transform:translateY(1px)}
.calc button:focus-visible{outline:none;box-shadow:var(--shadow-focus), inset 0 1px 0 rgba(255,255,255,0.10)}

/* Result panel */
.result{
  margin-top:18px;padding:16px 18px;
  background:linear-gradient(180deg, rgba(113,112,255,0.10), rgba(113,112,255,0.02));
  border:1px solid rgba(113,112,255,0.25);
  border-radius:var(--r-8);
  color:var(--t-primary);
  display:none;
  animation:fadeIn .25s ease;
}
.result.show{display:block}
.result .big{
  font-size:1.5rem;font-weight:590;letter-spacing:-0.022em;
  color:var(--t-primary);margin-bottom:4px;
}
.result strong{color:var(--t-primary);font-weight:590}
.result div{color:var(--t-secondary);font-size:.9375rem}
@keyframes fadeIn{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:none}}

.row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
@media(max-width:520px){.row{grid-template-columns:1fr}}

/* -------------------- Pills / badges -------------------- */
.pill{
  display:inline-flex;align-items:center;gap:6px;
  font-size:.75rem;font-weight:510;color:var(--t-secondary);
  padding:3px 10px;border-radius:9999px;
  border:1px solid var(--border-solid);background:transparent;
}

/* -------------------- Ad slots (subtle on dark) -------------------- */
.ad-slot[data-placeholder]::after{content:" (placeholder — wire up in /assets/ads.js)";opacity:.55;font-size:11px}
.ad-slot.ad-live{background:transparent;border:0;padding:0;min-height:0}
.ad-slot{
  margin:28px 0;padding:14px;
  background:var(--fill-1);
  border:1px dashed var(--border-std);
  border-radius:var(--r-8);
  text-align:center;color:var(--t-quaternary);
  font-size:.75rem;font-weight:510;letter-spacing:0.04em;text-transform:uppercase;
  min-height:96px;display:flex;align-items:center;justify-content:center;
}

/* -------------------- Breadcrumb -------------------- */
.breadcrumb{
  font-size:.8125rem;color:var(--t-tertiary);margin:8px 0 4px;letter-spacing:-0.005em;
}
.breadcrumb a{color:var(--t-tertiary)}
.breadcrumb a:hover{color:var(--t-secondary)}

/* -------------------- Footer -------------------- */
footer{
  border-top:1px solid var(--border-subtle);
  padding:28px 0;color:var(--t-quaternary);
  font-size:.8125rem;margin-top:48px;
}
footer a{color:var(--t-tertiary)}
footer a:hover{color:var(--t-secondary)}
footer .container{display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px}