/* AdFire Digital — digital advertising field guide */
:root{
  --bg:#14101d;
  --bg-2:#1c1628;
  --panel:#211a31;
  --panel-2:#271f3a;
  --line:#332a4a;
  --ink:#f4f1fa;
  --muted:#b3aac7;
  --faint:#8b81a3;
  --fire:#ff6a3d;
  --ember:#ff9248;
  --amber:#ffc24b;
  --grad:linear-gradient(100deg,#ff6a3d 0%,#ff9248 48%,#ffc24b 100%);
  --radius:16px;
  --maxw:1120px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  background:var(--bg);
  color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  font-size:17px;line-height:1.65;
  -webkit-font-smoothing:antialiased;
}
img,svg{max-width:100%;height:auto}
a{color:var(--ember);text-decoration:none}
a:hover{color:var(--amber)}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 22px}

/* ---------- header ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(20,16,29,.88);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.site-header .wrap{display:flex;align-items:center;gap:26px;padding-top:13px;padding-bottom:13px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:11px;font-weight:800;font-size:19px;color:var(--ink);letter-spacing:.2px}
.brand:hover{color:var(--ink)}
.brand .mark{width:30px;height:30px;flex:0 0 auto}
.brand em{font-style:normal;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.main-nav{display:flex;gap:4px;flex-wrap:wrap;margin-left:auto}
.main-nav a{
  color:var(--muted);font-size:14.5px;font-weight:600;
  padding:7px 12px;border-radius:9px;
}
.main-nav a:hover{color:var(--ink);background:var(--panel)}
.main-nav a.active{color:var(--amber);background:var(--panel)}

/* ---------- hero ---------- */
.hero{padding:74px 0 56px;background:
  radial-gradient(1100px 480px at 82% -10%,rgba(255,106,61,.16),transparent 60%),
  radial-gradient(800px 420px at 8% 0%,rgba(255,194,75,.07),transparent 55%),
  var(--bg);
}
.hero .wrap{display:grid;grid-template-columns:1.12fr .88fr;gap:48px;align-items:center}
.kicker{
  display:inline-block;font-size:12.5px;font-weight:800;letter-spacing:2.2px;text-transform:uppercase;
  color:var(--amber);border:1px solid var(--line);background:var(--panel);
  padding:6px 13px;border-radius:999px;margin-bottom:20px;
}
h1{font-size:clamp(32px,4.6vw,52px);line-height:1.12;font-weight:850;letter-spacing:-.5px;margin-bottom:18px}
h1 em{font-style:normal;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.lede{font-size:19px;color:var(--muted);max-width:56ch;margin-bottom:28px}
.btn-row{display:flex;gap:13px;flex-wrap:wrap}
.btn{
  display:inline-block;font-weight:750;font-size:15.5px;padding:13px 24px;border-radius:12px;
  background:var(--grad);color:#201020;border:0;
}
.btn:hover{color:#201020;filter:brightness(1.07)}
.btn.ghost{background:transparent;color:var(--ink);border:1px solid var(--line)}
.btn.ghost:hover{border-color:var(--ember);color:var(--amber)}
.hero-art{width:100%}

/* ---------- sections ---------- */
section{padding:56px 0}
section.alt{background:var(--bg-2);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.sec-head{max-width:720px;margin-bottom:36px}
.sec-head h2,h2.block{font-size:clamp(25px,3.2vw,34px);line-height:1.2;font-weight:800;letter-spacing:-.3px;margin-bottom:12px}
.sec-head p,.sub{color:var(--muted)}
h3{font-size:20px;font-weight:750;margin-bottom:8px}
h4{font-size:16.5px;font-weight:700;margin-bottom:6px}

/* ---------- cards ---------- */
.grid{display:grid;gap:20px}
.grid.c2{grid-template-columns:repeat(2,1fr)}
.grid.c3{grid-template-columns:repeat(3,1fr)}
.grid.c4{grid-template-columns:repeat(4,1fr)}
.card{
  background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);
  padding:26px;display:flex;flex-direction:column;gap:8px;
  transition:border-color .15s ease,transform .15s ease;
}
a.card:hover{transform:translateY(-3px);border-color:var(--fire)}
.card .icon{width:44px;height:44px;border-radius:12px;background:var(--panel-2);border:1px solid var(--line);display:flex;align-items:center;justify-content:center;margin-bottom:6px}
.card p{color:var(--muted);font-size:15.5px}
.card .more{margin-top:auto;font-size:14px;font-weight:750;color:var(--ember)}
.card:hover .more{color:var(--amber)}
.card h3 a{color:var(--ink)}
.card h3 a:hover{color:var(--amber)}

/* ---------- steps ---------- */
.steps{counter-reset:step;display:grid;gap:16px}
.step{
  counter-increment:step;display:grid;grid-template-columns:56px 1fr;gap:18px;align-items:start;
  background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:22px 24px;
}
.step::before{
  content:counter(step);display:flex;align-items:center;justify-content:center;
  width:44px;height:44px;border-radius:12px;background:var(--grad);
  color:#241121;font-weight:850;font-size:20px;
}
.step p{color:var(--muted);font-size:15.5px}

/* ---------- tables ---------- */
.tbl-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius);background:var(--panel)}
table{width:100%;border-collapse:collapse;font-size:15.5px;min-width:640px}
caption{text-align:left;padding:16px 20px 0;color:var(--faint);font-size:13.5px}
th,td{padding:14px 20px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
th{font-size:12.5px;letter-spacing:1.4px;text-transform:uppercase;color:var(--amber);background:var(--panel-2)}
tr:last-child td{border-bottom:0}
td code, p code, li code{
  background:var(--panel-2);border:1px solid var(--line);border-radius:6px;
  padding:1px 7px;font-size:.9em;color:var(--amber);
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}

/* ---------- article ---------- */
.crumbs{font-size:13.5px;color:var(--faint);padding:20px 0 0}
.crumbs a{color:var(--muted)}
.crumbs a:hover{color:var(--amber)}
.article{max-width:820px}
.article h1{font-size:clamp(30px,4vw,44px);margin:14px 0 16px}
.article .lede{margin-bottom:8px}
.article h2{font-size:26px;margin:40px 0 12px;letter-spacing:-.2px}
.article h3{font-size:19px;margin:28px 0 8px}
.article p{margin-bottom:16px;color:#ddd6ea}
.article ul,.article ol{margin:0 0 18px 22px;color:#ddd6ea}
.article li{margin-bottom:8px}
.article .figure{margin:28px 0}
.article .figure img,.content-visual img{
  display:block;width:100%;border:1px solid var(--line);border-radius:var(--radius);
  background:var(--panel);
}
.article .figure figcaption{font-size:13.5px;color:var(--faint);margin-top:10px;text-align:center}
.content-visual{margin:30px 0}
.content-visual figcaption{font-size:13.5px;color:var(--faint);margin-top:10px;text-align:center}
.byline{color:var(--faint);font-size:13.5px;margin:0 0 26px}
.sources{margin-top:44px;padding-top:22px;border-top:1px solid var(--line)}
.sources h2{margin-top:0}
.sources li{font-size:14.5px;color:var(--muted)}
.decision-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;margin:22px 0}
.decision-grid .card{padding:20px}
.callout{
  border:1px solid var(--line);border-left:4px solid var(--fire);
  background:var(--panel);border-radius:12px;padding:18px 22px;margin:24px 0;
}
.callout p{margin:0;color:var(--muted);font-size:15.5px}
.callout strong{color:var(--ink)}

/* ---------- FAQ ---------- */
.faq details{
  background:var(--panel);border:1px solid var(--line);border-radius:12px;margin-bottom:12px;padding:0;
}
.faq summary{
  cursor:pointer;list-style:none;padding:18px 22px;font-weight:700;font-size:16.5px;
  display:flex;justify-content:space-between;gap:16px;align-items:center;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--ember);font-size:22px;font-weight:800;flex:0 0 auto}
.faq details[open] summary::after{content:"–"}
.faq details p{padding:0 22px 18px;color:var(--muted);font-size:15.5px}

/* ---------- glossary ---------- */
.glossary dt{font-weight:800;color:var(--amber);margin-top:22px;font-size:17.5px}
.glossary dd{color:#ddd6ea;margin:4px 0 0}
.glossary .letter{
  margin-top:44px;padding-top:14px;border-top:1px solid var(--line);
  font-size:13px;letter-spacing:2.5px;text-transform:uppercase;color:var(--faint);font-weight:800;
}

/* ---------- CTA band ---------- */
.band{
  background:var(--grad);border-radius:20px;padding:40px 44px;color:#241121;
  display:flex;gap:26px;align-items:center;justify-content:space-between;flex-wrap:wrap;
}
.band h2{font-size:clamp(22px,2.8vw,30px);font-weight:850;letter-spacing:-.3px}
.band p{max-width:52ch;font-weight:550}
.band .btn{background:#1c1628;color:var(--ink)}
.band .btn:hover{color:var(--amber)}

/* ---------- footer ---------- */
.site-footer{border-top:1px solid var(--line);background:var(--bg-2);padding:44px 0 34px;margin-top:20px}
.site-footer .cols{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:34px;margin-bottom:30px}
.site-footer h4{color:var(--ink);margin-bottom:12px;font-size:14px;letter-spacing:1.6px;text-transform:uppercase}
.site-footer ul{list-style:none}
.site-footer li{margin-bottom:8px}
.site-footer a{color:var(--muted);font-size:15px}
.site-footer a:hover{color:var(--amber)}
.site-footer p{color:var(--faint);font-size:14.5px;max-width:44ch}
.legal{border-top:1px solid var(--line);padding-top:22px;font-size:13.5px;color:var(--faint);display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap}

/* ---------- responsive ---------- */
@media (max-width:900px){
  .hero .wrap{grid-template-columns:1fr;gap:34px}
  .hero{padding:52px 0 44px}
  .grid.c3,.grid.c4{grid-template-columns:repeat(2,1fr)}
  .site-footer .cols{grid-template-columns:1fr 1fr}
}
@media (max-width:560px){
  body{font-size:16px}
  .grid.c2,.grid.c3,.grid.c4{grid-template-columns:1fr}
  .site-header .wrap{gap:12px}
  .main-nav{margin-left:0;width:100%}
  .main-nav a{padding:6px 10px;font-size:14px}
  section{padding:44px 0}
  .step{grid-template-columns:44px 1fr;gap:14px;padding:18px}
  .step::before{width:36px;height:36px;font-size:17px}
  .band{padding:30px 26px}
  .site-footer .cols{grid-template-columns:1fr}
  .lede{font-size:17px}
  .decision-grid{grid-template-columns:1fr}
}