/* =====================================================================
   Check.Fast — Blog stylesheet (v2)
   Shared by every page in /blog. Same font system as the homepage:
   Geist for text/UI, Geist Mono for labels & numbers (self-hosted, SIL OFL).
   ===================================================================== */
@font-face{font-family:'Geist';src:url(/assets/fonts/Geist-Variable.woff2) format('woff2');font-weight:100 900;font-style:normal;font-display:swap}
@font-face{font-family:'Geist Mono';src:url(/assets/fonts/GeistMono-Variable.woff2) format('woff2');font-weight:100 900;font-style:normal;font-display:swap}

:root{
  --sans:'Geist',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,system-ui,sans-serif;
  --mono:'Geist Mono',ui-monospace,'SF Mono','JetBrains Mono',Menlo,Consolas,monospace;
  --bg:#05090a;--bg2:#0b1214;--ink:#e9f6ef;--text:#c5d8ce;--muted:#7f9b8d;--cyan:#1cff9e;--cyan2:#0bd584;
  --track:#15221e;--track2:#20342c;--lime:#a6f53d;--hair:rgba(255,255,255,.06);
  --surface:rgba(14,22,24,.72);--glow:rgba(28,255,158,.3);
  --ease:cubic-bezier(.2,.8,.2,1);--spring:cubic-bezier(.34,1.56,.64,1);
  --shadow:0 1px 0 rgba(255,255,255,.04) inset,0 10px 30px -12px rgba(0,0,0,.6);
}
body.light{
  --bg:#f5f8f6;--bg2:#ffffff;--ink:#0a1912;--text:#26372f;--muted:#5b7166;--cyan:#0a9d63;--cyan2:#0a9d63;
  --track:#e2eae5;--track2:#d0ddd5;--lime:#0a9d63;--hair:rgba(10,40,25,.06);
  --surface:rgba(255,255,255,.8);--glow:rgba(10,157,99,.25);
  --shadow:0 1px 2px rgba(10,40,25,.04),0 12px 32px -14px rgba(10,40,25,.16);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--bg)}
body{
  background:
    radial-gradient(900px 480px at 50% -120px,color-mix(in srgb,var(--cyan) 13%,transparent),transparent 70%),
    var(--bg);
  color:var(--ink);font-family:var(--sans);font-optical-sizing:auto;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
  line-height:1.7;min-height:100vh;transition:background-color .4s,color .4s;letter-spacing:-.005em}
::selection{background:color-mix(in srgb,var(--cyan) 26%,transparent)}
:focus-visible{outline:2px solid var(--cyan);outline-offset:2px;border-radius:4px}
a{color:var(--cyan);text-decoration:none}
a:hover{text-decoration:underline;text-underline-offset:3px}
.wrap{max-width:760px;margin:0 auto;padding:0 22px}

/* ---------- reading progress ---------- */
.read-progress{position:fixed;left:0;top:0;height:2px;width:100%;z-index:100;transform-origin:0 50%;transform:scaleX(0);
  background:linear-gradient(90deg,var(--cyan),#c8ff3d);box-shadow:0 0 10px var(--glow)}

/* ---------- header ---------- */
.top{position:sticky;top:0;z-index:50;border-bottom:1px solid transparent;
  transition:background .3s,border-color .3s}
.top.scrolled{background:color-mix(in srgb,var(--bg) 74%,transparent);
  -webkit-backdrop-filter:saturate(1.6) blur(14px);backdrop-filter:saturate(1.6) blur(14px);border-bottom-color:var(--hair)}
.top .wrap{display:flex;align-items:center;justify-content:space-between;padding:14px 22px;max-width:1080px}
.logo{display:flex;align-items:center;gap:7px;font-weight:700;font-size:19px;color:var(--ink);letter-spacing:-.035em;text-decoration:none}
.logo:hover{text-decoration:none}
.logo .dot{color:var(--lime);font-weight:800;margin:0 -6px}
.logo svg{width:26px;height:26px;transition:transform .5s var(--spring)}
.logo:hover svg{transform:rotate(-8deg) scale(1.08)}
.nav{display:flex;align-items:center;gap:4px}
.nav a{color:var(--muted);font-size:14px;font-weight:500;padding:8px 12px;border-radius:9px;transition:color .2s,background .2s}
.nav a:hover{color:var(--ink);background:var(--hair);text-decoration:none}
.nav a[href="/"]{color:var(--ink);border:1px solid var(--track2);background:var(--surface);margin-right:6px}
.nav a[href="/"]:hover{border-color:var(--cyan);color:var(--cyan)}
.theme-btn{background:var(--surface);border:1px solid var(--track2);color:var(--cyan);width:38px;height:38px;border-radius:11px;cursor:pointer;
  display:inline-flex;align-items:center;justify-content:center;vertical-align:middle;margin-left:4px;
  transition:border-color .2s,transform .2s var(--spring),box-shadow .2s}
.theme-btn:hover{border-color:var(--cyan);transform:translateY(-1px);box-shadow:0 0 14px var(--glow)}
.theme-btn:active{transform:scale(.94)}

/* ---------- blog index hero + cards ---------- */
.wrap:has(> .hero){max-width:1080px}
.hero{padding:70px 0 34px;text-align:center}
.hero h1{font-size:clamp(34px,5.6vw,56px);font-weight:700;letter-spacing:-.045em;line-height:1.05;margin-bottom:16px;
  background:linear-gradient(180deg,#f4fff9 20%,#8fcfb4);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;
  animation:riseIn .8s var(--ease) both}
body.light .hero h1{background:linear-gradient(180deg,#0a1912 35%,#0a8f5a);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.hero p{color:var(--muted);font-size:18px;max-width:600px;margin:0 auto;animation:riseIn .8s .08s var(--ease) both}
.posts{display:grid;gap:16px;padding:20px 0 40px}
.hero ~ .posts{grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:18px}
.card{position:relative;isolation:isolate;display:flex;flex-direction:column;background:var(--surface);border:1px solid var(--track);border-radius:18px;padding:24px;
  box-shadow:var(--shadow);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);
  transition:border-color .3s,transform .35s var(--ease),box-shadow .35s}
.card::before{content:"";position:absolute;inset:0;border-radius:inherit;z-index:-1;opacity:0;transition:opacity .3s;pointer-events:none;
  background:radial-gradient(280px circle at var(--mx,50%) var(--my,0%),color-mix(in srgb,var(--cyan) 11%,transparent),transparent 60%)}
.card:hover{border-color:color-mix(in srgb,var(--cyan) 45%,var(--track));transform:translateY(-4px);text-decoration:none;
  box-shadow:var(--shadow),0 18px 40px -18px var(--glow)}
.card:hover::before{opacity:1}
.card .tag{display:inline-flex;align-self:flex-start;font-size:10.5px;font-family:var(--mono);font-weight:500;text-transform:uppercase;letter-spacing:.12em;
  color:var(--cyan);margin-bottom:12px;padding:4px 9px;border-radius:999px;background:color-mix(in srgb,var(--cyan) 9%,transparent);
  border:1px solid color-mix(in srgb,var(--cyan) 20%,transparent)}
.card h2{font-size:20px;font-weight:600;color:var(--ink);margin-bottom:8px;line-height:1.3;letter-spacing:-.025em}
.card p{color:var(--muted);font-size:15px;line-height:1.6}
.card .meta{color:var(--muted);font-family:var(--mono);font-size:11.5px;margin-top:auto;padding-top:16px;opacity:.85;letter-spacing:.02em}
.card .meta::after{content:" →";color:var(--cyan);opacity:0;display:inline-block;transform:translateX(-4px);transition:opacity .25s,transform .3s var(--ease)}
.card:hover .meta::after{opacity:1;transform:none}
.pager{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;align-items:center;padding:10px 0 80px}
.pager .pg{display:inline-flex;align-items:center;justify-content:center;min-width:42px;height:42px;padding:0 13px;
  border:1px solid var(--track);border-radius:12px;color:var(--muted);font-family:var(--mono);font-weight:500;font-size:14px;background:var(--surface);
  text-decoration:none;transition:border-color .2s,color .2s,background .2s,transform .2s var(--spring)}
.pager .pg:hover{border-color:var(--cyan);color:var(--cyan);transform:translateY(-2px);text-decoration:none}
.pager .pg-cur{background:var(--cyan);color:#04130d;border-color:var(--cyan)}
body.light .pager .pg-cur{color:#fff}

/* ---------- article ---------- */
article{padding:56px 0 80px}
article > .tag{display:inline-flex;font-size:11px;font-family:var(--mono);font-weight:500;text-transform:uppercase;letter-spacing:.12em;color:var(--cyan);
  margin-bottom:18px;padding:5px 11px;border-radius:999px;background:color-mix(in srgb,var(--cyan) 9%,transparent);
  border:1px solid color-mix(in srgb,var(--cyan) 22%,transparent);animation:riseIn .7s var(--ease) both}
article h1{font-size:clamp(32px,5.2vw,48px);font-weight:700;letter-spacing:-.045em;line-height:1.08;margin-bottom:16px;animation:riseIn .8s .05s var(--ease) both}
article .meta{color:var(--muted);font-family:var(--mono);font-size:12.5px;margin-bottom:26px;padding-bottom:22px;border-bottom:1px solid var(--hair);
  letter-spacing:.02em;animation:riseIn .8s .1s var(--ease) both}
article h2{font-size:26px;font-weight:650;margin:46px 0 14px;letter-spacing:-.03em;line-height:1.25;scroll-margin-top:90px}
article h3{font-size:19px;font-weight:600;margin:30px 0 10px;color:var(--ink);letter-spacing:-.02em}
article p{margin-bottom:18px;font-size:17.5px;color:var(--text);line-height:1.78}
article ul,article ol{margin:0 0 20px 24px;color:var(--text)}
article li{margin-bottom:10px;font-size:17.5px;padding-left:4px;line-height:1.7}
article li::marker{color:var(--cyan);font-family:var(--mono);font-size:.9em}
article strong{color:var(--ink);font-weight:600}
article p a,article li a{text-decoration:underline;text-decoration-color:color-mix(in srgb,var(--cyan) 40%,transparent);text-underline-offset:3px;text-decoration-thickness:1.5px;transition:text-decoration-color .2s}
article p a:hover,article li a:hover{text-decoration-color:var(--cyan)}
article .cta{position:relative;overflow:hidden;display:block;border-radius:20px;padding:34px 26px;margin:44px 0;text-align:center;
  border:1px solid transparent;
  background:linear-gradient(var(--bg2),var(--bg2)) padding-box,
             conic-gradient(from var(--ang,0deg),var(--track2),var(--cyan),#c8ff3d,var(--track2) 40%,var(--track2)) border-box;
  animation:edgeSpin 6s linear infinite;box-shadow:var(--shadow)}
article .cta::before{content:"";position:absolute;left:50%;top:-120px;width:420px;height:240px;margin-left:-210px;pointer-events:none;
  background:radial-gradient(closest-side,color-mix(in srgb,var(--cyan) 18%,transparent),transparent)}
@property --ang{syntax:'<angle>';initial-value:0deg;inherits:false}
@keyframes edgeSpin{to{--ang:360deg}}
article .cta b{position:relative;font-size:22px;font-weight:650;letter-spacing:-.03em;color:var(--ink)}
article .cta p{position:relative;color:var(--muted);font-size:15px;margin:8px 0 20px}
article .cta a{position:relative;overflow:hidden;display:inline-block;background:var(--cyan);color:#04130d;font-weight:600;padding:13px 28px;border-radius:12px;font-size:16px;
  box-shadow:0 10px 26px -8px var(--glow);transition:transform .25s var(--spring),box-shadow .25s}
body.light article .cta a{color:#fff}
article .cta a::after{content:"";position:absolute;inset:0;background:linear-gradient(115deg,transparent 30%,rgba(255,255,255,.4) 50%,transparent 70%);transform:translateX(-120%);transition:transform .8s var(--ease)}
article .cta a:hover{transform:translateY(-2px);text-decoration:none;box-shadow:0 16px 34px -8px var(--glow)}
article .cta a:hover::after{transform:translateX(120%)}
.back{color:var(--muted);font-size:14px;display:inline-flex;align-items:center;gap:6px;margin-top:34px;font-weight:500;transition:color .2s,gap .25s var(--ease)}
.back:hover{color:var(--cyan);text-decoration:none;gap:10px}
/* charts & diagrams: always shown on a dark "instrument" panel so their colours read correctly in both themes */
article figure{margin:30px 0;background:radial-gradient(120% 100% at 50% 0%,#0f1c18,#070d0e);border:1px solid #1b2c25;border-radius:18px;padding:24px;overflow:hidden;box-shadow:var(--shadow)}
article figure svg{width:100%;max-width:560px;margin:0 auto;height:auto;display:block;border-radius:8px}
article figure svg text{font-family:var(--sans)}
article figcaption{color:var(--muted);font-size:13px;text-align:center;margin-top:14px;font-family:var(--mono);letter-spacing:.01em}
body.light article figcaption{color:#8fa89b}
article table.cmp{width:100%;border-collapse:separate;border-spacing:0;margin:26px 0;font-size:15px;border:1px solid var(--track);border-radius:14px;overflow:hidden;background:var(--surface)}
article table.cmp th,article table.cmp td{border-bottom:1px solid var(--track);padding:12px 14px;text-align:left;color:var(--text)}
article table.cmp tr:last-child td{border-bottom:none}
article table.cmp th{background:color-mix(in srgb,var(--cyan) 6%,var(--bg2));color:var(--ink);font-weight:600;font-size:13px;font-family:var(--mono);letter-spacing:.03em}
article table.cmp tbody tr{transition:background .2s}
article table.cmp tbody tr:hover{background:color-mix(in srgb,var(--cyan) 4%,transparent)}
article .keytake{position:relative;background:color-mix(in srgb,var(--cyan) 6%,var(--bg2));border:1px solid color-mix(in srgb,var(--cyan) 20%,var(--track));
  border-radius:14px;padding:18px 20px 18px 22px;margin:28px 0;color:var(--text)}
article .keytake::before{content:"";position:absolute;left:0;top:14px;bottom:14px;width:3px;border-radius:3px;background:linear-gradient(var(--cyan),#c8ff3d)}
article .keytake b{color:var(--ink);font-weight:600}
/* related guides block inside articles */
article section .posts .card{padding:18px!important;box-shadow:none}
article section .posts .card h2{margin:0}

/* ---------- footer ---------- */
.foot{border-top:1px solid var(--hair);padding:36px 0 44px;color:var(--muted);font-size:13px;text-align:center}
.foot a{color:var(--muted);margin:0 8px;transition:color .2s}
.foot a:hover{color:var(--cyan);text-decoration:none}

/* ---------- motion ---------- */
@keyframes riseIn{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
.reveal{opacity:0;transform:translateY(18px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.reveal.in{opacity:1;transform:none}

@media(max-width:600px){
  .top .wrap{padding:12px 16px}
  .nav a{padding:7px 9px;font-size:13.5px}
  .nav a[href="/"]{margin-right:2px}
  .hero{padding:48px 0 20px}
  .hero ~ .posts{grid-template-columns:1fr}
  article{padding:40px 0 60px}
  article p,article li{font-size:16.5px}
  article h2{font-size:22px}
  article figure{padding:16px}
  article table.cmp{font-size:13.5px;display:block;overflow-x:auto}
}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important;scroll-behavior:auto!important}
  .reveal{opacity:1;transform:none}
}

/* headline: solid colour (no gradient) */
.hero h1,body.light .hero h1{background:none;-webkit-background-clip:border-box;background-clip:border-box;-webkit-text-fill-color:currentColor;color:var(--ink)}

/* headline: rich emerald (matches homepage) */
body.light .hero h1{background:linear-gradient(100deg,#064e3b 0%,#0a8a5a 50%,#0bb277 100%);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
body:not(.light) .hero h1{background:linear-gradient(100deg,#eafff4 0%,#8dffcc 60%,#3ef0a0 100%);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}

/* headline: speedometer-green gradient (matches homepage) */
body.light .hero h1{background:linear-gradient(100deg,#06a067 0%,#0bd584 50%,#4cf5a8 100%);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
body:not(.light) .hero h1{background:linear-gradient(100deg,#0bd584 0%,#34e89e 50%,#7dffc4 100%);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}