/* Defensible AI — site styles */
:root{
  --ink:#160F0A; --ink2:#1D140C; --panel:#211710; --panel2:#191009;
  --brass:#C8911E; --amber:#E9A93C; --off:#F5EFE6; --cyan:#34B8C4;
  --red:#D2502E; --muted:#9A8C7A; --line:#3A2A1C; --linedim:#2C1F14;
  --disp:'Archivo Black',system-ui,sans-serif;
  --body:'Inter',system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  --mono:'JetBrains Mono',ui-monospace,Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--ink);color:var(--off);font-family:var(--body);
  font-size:16.5px;line-height:1.65;-webkit-font-smoothing:antialiased}
img{max-width:100%;height:auto;display:block}
a{color:var(--amber)}
a:hover{color:var(--off)}
:focus-visible{outline:3px solid var(--cyan);outline-offset:3px;border-radius:4px}
.wrap{max-width:1100px;margin:0 auto;padding:0 22px}
.eyebrow{font-family:var(--mono);font-size:12.5px;letter-spacing:3px;text-transform:uppercase;
  color:var(--brass);font-weight:700;margin:0 0 14px}
h1,h2,h3{font-family:var(--disp);font-weight:400;line-height:1.08;margin:0 0 18px;letter-spacing:.3px}
h1{font-size:clamp(34px,5.6vw,58px)}
h2{font-size:clamp(26px,3.6vw,38px)}
h3{font-size:20px;line-height:1.3}
p{margin:0 0 16px}
.lede{font-size:19px;color:#D8CFC1;max-width:62ch}
.term{color:var(--amber);font-weight:600}
.mono{font-family:var(--mono)}

/* header */
.site-head{position:sticky;top:0;z-index:50;background:rgba(22,15,10,.92);
  border-bottom:1px solid var(--linedim);backdrop-filter:blur(8px)}
.site-head .bar{display:flex;align-items:center;gap:22px;padding:14px 0}
.logo{font-family:var(--disp);font-size:17px;letter-spacing:1.5px;color:var(--off);text-decoration:none;white-space:nowrap}
.logo b{color:var(--brass)}
.nav{display:flex;gap:2px;align-items:center;flex:1}
.nav a{color:#CDBFA9;text-decoration:none;font-size:14.5px;font-weight:500;margin-right:18px}
.nav a:hover,.nav a[aria-current]{color:var(--off)}
.nav a[aria-current]{border-bottom:2px solid var(--brass);padding-bottom:3px}
.btn{display:inline-block;background:var(--brass);color:#1A1208;text-decoration:none;
  font-weight:700;font-size:15px;padding:12px 22px;border-radius:9px;border:0;cursor:pointer;
  font-family:var(--body);transition:transform .08s ease,background .2s}
.btn:hover{background:var(--amber);color:#1A1208}
.btn:active{transform:translateY(1px)}
.btn.ghost{background:transparent;color:var(--off);border:1.5px solid var(--line)}
.btn.ghost:hover{border-color:var(--brass);color:var(--amber);background:transparent}
.btn.small{padding:9px 16px;font-size:14px}
.menu-btn{display:none;background:none;border:1.5px solid var(--line);color:var(--off);
  border-radius:8px;padding:8px 12px;font-size:18px;cursor:pointer}

/* hero */
.hero{padding:84px 0 30px;position:relative}
.hero .split{display:flex;gap:48px;align-items:center;flex-wrap:wrap}
.hero .copy{flex:1 1 460px;min-width:300px}
.hero .visual{flex:0 1 320px;min-width:260px;display:flex;justify-content:center}
.hero .visual img{width:280px;box-shadow:0 24px 60px rgba(0,0,0,.55);border-radius:6px}
.cta-row{display:flex;gap:14px;flex-wrap:wrap;margin-top:26px}
.equation-live{font-family:var(--mono);font-size:clamp(19px,3vw,26px);color:var(--muted);
  margin-top:34px;letter-spacing:.5px}
.equation-live .r{color:var(--amber);font-weight:700}
.equation-live .crit{color:var(--red);font-weight:700}
.equation-live .safe{color:var(--cyan);font-weight:700}

/* pixel dissolve divider (signature) */
.dissolve{height:46px;position:relative;overflow:hidden;margin:8px 0}
.dissolve i{position:absolute;display:block;background:var(--brass)}

/* sections */
.section{padding:64px 0}
.section.alt{background:var(--ink2)}
.section .head{max-width:720px;margin-bottom:34px}
.cards{display:flex;gap:18px;flex-wrap:wrap}
.card{flex:1 1 280px;min-width:250px;background:var(--panel);border:1px solid var(--linedim);
  border-radius:14px;padding:26px 24px;transition:border-color .25s}
.card:hover{border-color:var(--line)}
.card .k{font-family:var(--mono);color:var(--brass);font-size:13px;letter-spacing:2px;
  text-transform:uppercase;margin-bottom:10px}
.card h3{margin-bottom:10px}
.card p{color:#CFC4B4;font-size:15.5px;margin:0}
.card .big{font-family:var(--disp);font-size:46px;color:var(--amber);line-height:1;margin:6px 0 10px}
.card.accent{border-top:3px solid var(--brass)}
.card.cy{border-top:3px solid var(--cyan)}

/* book strip */
.bookstrip{display:flex;gap:40px;align-items:center;flex-wrap:wrap}
.bookstrip .cover{flex:0 0 220px}
.bookstrip .cover img{box-shadow:0 18px 44px rgba(0,0,0,.5);border-radius:5px}
.bookstrip .body{flex:1 1 420px;min-width:300px}
.buyrow{display:flex;gap:12px;flex-wrap:wrap;margin-top:20px}
.meta{font-family:var(--mono);font-size:13px;color:var(--muted);margin-top:18px}

/* author */
.authorstrip{display:flex;gap:36px;align-items:flex-start;flex-wrap:wrap}
.headshot{flex:0 0 180px;width:180px;height:180px;border-radius:50%;background:var(--panel);
  border:2px solid var(--line);display:flex;align-items:center;justify-content:center;
  font-family:var(--disp);font-size:52px;color:var(--brass)}
.creds{list-style:none;padding:0;margin:18px 0 0;display:flex;flex-direction:column;gap:10px}
.creds li{padding-left:26px;position:relative;color:#D8CFC1;font-size:15.5px}
.creds li::before{content:"";position:absolute;left:0;top:8px;width:10px;height:10px;background:var(--brass)}

/* forms */
.form-card{background:var(--panel);border:1px solid var(--linedim);border-radius:14px;padding:28px 26px}
label{display:block;font-weight:600;font-size:14.5px;margin:16px 0 6px}
input[type=text],input[type=email],textarea,select{width:100%;background:var(--panel2);
  border:1.5px solid var(--line);border-radius:9px;color:var(--off);padding:12px 14px;
  font-family:var(--body);font-size:15.5px}
input:focus,textarea:focus,select:focus{border-color:var(--brass);outline:none}
textarea{min-height:120px;resize:vertical}
.form-note{font-size:13px;color:var(--muted);margin-top:12px}
.hp{position:absolute;left:-9999px}

/* banner */
.banner{background:linear-gradient(135deg,#241910,#19110A);border:1px solid var(--line);
  border-radius:16px;padding:36px 32px;display:flex;gap:26px;align-items:center;flex-wrap:wrap}
.banner .grow{flex:1 1 380px}
.banner h2{margin-bottom:8px}
.banner p{color:#D0C5B5;margin:0}

/* footer */
.site-foot{border-top:1px solid var(--linedim);padding:46px 0 36px;margin-top:30px}
.site-foot .cols{display:flex;gap:36px;flex-wrap:wrap;justify-content:space-between}
.site-foot .col{flex:1 1 220px;min-width:200px}
.site-foot h4{font-family:var(--mono);font-size:12.5px;letter-spacing:2px;text-transform:uppercase;
  color:var(--brass);margin:0 0 12px}
.site-foot a{color:#CDBFA9;text-decoration:none;display:block;font-size:14.5px;margin-bottom:8px}
.site-foot a:hover{color:var(--off)}
.site-foot .legal{margin-top:34px;padding-top:18px;border-top:1px solid var(--linedim);
  font-size:12.5px;color:var(--muted);font-family:var(--mono)}
.newsform{display:flex;gap:10px;flex-wrap:wrap;margin-top:6px}
.newsform input{flex:1 1 180px}

/* mobile */
@media (max-width:760px){
  .menu-btn{display:block;margin-left:auto}
  .nav{display:none;position:absolute;top:100%;left:0;right:0;background:var(--ink2);
    flex-direction:column;align-items:flex-start;padding:18px 22px;gap:16px;
    border-bottom:1px solid var(--line)}
  .nav.open{display:flex}
  .site-head .btn{display:none}
  .hero{padding:54px 0 20px}
  .section{padding:48px 0}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .dissolve i{animation:none!important}
}

/* form feedback */
.form-success{background:linear-gradient(180deg,#173a32,#10241f);border:1px solid var(--cyan);
  color:var(--off);border-radius:14px;padding:22px 24px;font-size:16px;line-height:1.6}
.form-success strong{color:var(--cyan)}
.form-error{color:#F6C9BB;background:rgba(210,80,46,.12);border:1px solid var(--red);
  border-radius:9px;padding:10px 13px;margin-top:14px;font-size:14px}
button[type=submit]:disabled{opacity:.6;cursor:progress}