/* =========================================================================
   Sales for Engineers : landing page
   Aesthetic: editorial book gravitas x code/terminal precision.
   White paper, one electric blue, the { } wordmark as the structural spine.
   ========================================================================= */

:root {
  --paper:#FFFFFF;
  --ink:#0A0A0A;
  --muted:#5A6470;
  --line:#E6E8EC;
  --wash:#F5F6F8;
  --blue:#0F62FE;
  --blue-press:#0043CE;
  --blue-wash:#EAF0FF;

  --font-display:'Bricolage Grotesque',Georgia,serif;
  --font-serif:'Newsreader',Georgia,'Times New Roman',serif;
  --font-mono:'JetBrains Mono',ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --maxw:74rem;
  --gutter:clamp(1.25rem,5vw,4.5rem);
  --section-y:clamp(3.25rem,8vw,6.5rem);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-serif);
  font-size:clamp(1.0625rem,0.62vw + 0.95rem,1.1875rem);
  line-height:1.62;
  font-feature-settings:"liga" 1,"kern" 1;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
img{display:block;max-width:100%;height:auto}
a{color:var(--blue);text-underline-offset:.18em;text-decoration-thickness:1px}
a:hover{color:var(--blue-press)}
strong{font-weight:600}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}

/* ---- giant decorative braces: the brand spine ---- */
.brace{
  position:fixed;top:50%;transform:translateY(-50%);
  font-family:var(--font-display);font-weight:800;
  font-size:min(58vh,52vw);line-height:1;
  color:var(--blue);opacity:.05;z-index:0;pointer-events:none;
  user-select:none;
}
.brace-open{left:-.12em}
.brace-close{right:-.12em}

main,footer{position:relative;z-index:1}
main{max-width:var(--maxw);margin:0 auto;padding:0 var(--gutter)}

/* ---- shared section rhythm ---- */
.block{padding:var(--section-y) 0;border-top:1px solid var(--line)}
.section-label{
  font-family:var(--font-mono);font-weight:500;font-size:.8rem;
  letter-spacing:.04em;color:var(--blue);margin-bottom:.85rem;
}
h2{
  font-family:var(--font-display);font-weight:800;
  font-size:clamp(1.7rem,3.4vw + .4rem,2.7rem);
  line-height:1.08;letter-spacing:-.02em;max-width:18ch;
}
h3{font-family:var(--font-display);font-weight:700}

/* ============================ HERO ============================ */
.hero{
  display:grid;grid-template-columns:1.15fr .85fr;
  gap:clamp(2rem,5vw,5rem);align-items:center;
  min-height:min(92vh,52rem);padding:clamp(4rem,9vw,7rem) 0 var(--section-y);
}
.eyebrow{
  font-family:var(--font-mono);font-weight:700;font-size:.82rem;
  letter-spacing:.08em;color:var(--blue);margin-bottom:1.6rem;
}
h1{
  font-family:var(--font-display);font-weight:800;
  font-size:clamp(3.1rem,9.2vw,6.6rem);
  line-height:.92;letter-spacing:-.035em;
  margin-bottom:1.1rem;
}
.subtitle{
  font-family:var(--font-display);font-weight:700;
  font-size:clamp(1.05rem,1.6vw + .4rem,1.5rem);
  line-height:1.2;color:var(--ink);margin-bottom:2.2rem;letter-spacing:-.01em;
}
.hook{
  font-style:italic;font-size:clamp(1.25rem,2vw + .5rem,1.7rem);
  line-height:1.3;color:var(--ink);
  border-left:3px solid var(--blue);padding-left:1.1rem;margin-bottom:1.5rem;
}
.lede{color:var(--muted);max-width:46ch;margin-bottom:2.4rem}
.cta-note{
  font-family:var(--font-mono);font-size:.78rem;line-height:1.55;
  color:var(--muted);margin-top:1rem;max-width:42ch;
}

/* book cover, a real object on white paper */
.hero-cover{perspective:1600px}
.hero-cover img{
  width:100%;max-width:25rem;margin-inline:auto;
  transform:rotateY(-9deg) rotateX(2.5deg);
  transform-origin:center;
  box-shadow:
    -.5rem .7rem 1.4rem rgba(10,10,10,.10),
    -1.4rem 2rem 3.5rem rgba(10,10,10,.16);
  border:1px solid var(--line);
}

/* ============================ BUTTONS ============================ */
.btn{
  display:inline-flex;align-items:center;gap:.55rem;
  font-family:var(--font-display);font-weight:700;font-size:1.02rem;
  padding:.95rem 1.7rem;border:2px solid var(--blue);border-radius:0;
  text-decoration:none;cursor:pointer;
  transition:transform .12s ease,background .15s ease,color .15s ease;
}
.btn .arr{transition:transform .15s ease}
.btn:hover .arr{transform:translateX(.25rem)}
.btn-primary{background:var(--blue);color:#fff}
.btn-primary:hover{background:var(--blue-press);border-color:var(--blue-press);color:#fff;transform:translateY(-2px)}
.btn-secondary{background:transparent;color:var(--blue)}
.btn-secondary:hover{background:var(--blue);color:#fff;transform:translateY(-2px)}
.btn:focus-visible{outline:3px solid var(--ink);outline-offset:3px}

/* ============================ WHO ============================ */
.who-list{list-style:none;margin-top:1.8rem;display:grid;gap:1rem;max-width:60ch}
.who-list li{position:relative;padding-left:2.2rem;font-size:1.08rem}
.who-list li::before{
  content:"{}";position:absolute;left:0;top:.05em;
  font-family:var(--font-mono);font-weight:700;color:var(--blue);font-size:.95em;
}

/* ===================== INSIDE THIS BOOK ===================== */
/* twin blue rules mirror the physical back-cover design language */
.inside{border-top:2px solid var(--blue);border-bottom:2px solid var(--blue)}
.grid{
  margin-top:2rem;display:grid;grid-template-columns:repeat(2,1fr);
  gap:1px;background:var(--line);
  border:1px solid var(--line);
}
.grid article{
  background:var(--paper);padding:clamp(1.4rem,2.6vw,2.1rem);
  display:flex;gap:1.1rem;align-items:flex-start;
}
.grid .num{
  font-family:var(--font-mono);font-weight:700;font-size:1.05rem;
  color:var(--blue);flex:none;padding-top:.18rem;
}
.grid p{font-family:var(--font-display);font-weight:700;font-size:1.12rem;line-height:1.28;letter-spacing:-.01em}

/* ============================ TOC ============================ */
details{border-top:1px solid var(--line)}
#toc details{border:1px solid var(--line);margin-top:1.6rem}
summary{
  font-family:var(--font-mono);font-weight:700;font-size:.95rem;
  padding:1.15rem 1.3rem;cursor:pointer;list-style:none;
  display:flex;justify-content:space-between;align-items:center;gap:1rem;
  color:var(--ink);
}
summary::-webkit-details-marker{display:none}
summary::after{content:"[ + ]";color:var(--blue);font-family:var(--font-mono)}
details[open] summary::after{content:"[ \2212 ]"}
#toc .summary-hide{display:none}
#toc details[open] .summary-show{display:none}
#toc details[open] .summary-hide{display:inline}
.toc{
  padding:.5rem clamp(1rem,2.5vw,1.6rem) 1.6rem;
  display:grid;grid-template-columns:repeat(2,1fr);gap:1.5rem 2.5rem;
}
.toc-part h3{
  font-family:var(--font-mono);font-weight:700;font-size:.82rem;
  letter-spacing:.03em;color:var(--blue);
  padding-bottom:.5rem;margin-bottom:.6rem;border-bottom:1px solid var(--line);
}
.toc ol,.toc ul{margin-left:1.15rem;display:grid;gap:.32rem}
.toc li{font-size:.98rem;line-height:1.4}
.toc-bonus{list-style:none;margin-left:0!important}
.toc em{color:var(--muted);font-size:.92em}

/* ============================ AUTHOR ============================ */
.author-grid{
  display:grid;grid-template-columns:1.4fr .6fr;
  gap:clamp(2rem,5vw,4.5rem);align-items:start;
}
.author-copy p{max-width:60ch;margin-top:1.1rem;color:var(--ink)}
.author-copy p:first-of-type{margin-top:1.8rem}

/* portrait: cutout floats on a paper panel over a hard blue block */
.author-photo{position:relative;margin-top:2rem;align-self:start}
.author-photo::before{
  content:"";position:absolute;inset:0;z-index:0;
  background:var(--blue);transform:translate(.85rem,.85rem);
}
.author-photo img{
  position:relative;z-index:1;display:block;width:100%;height:auto;
  background:var(--wash);border:1px solid var(--ink);
}
.author-photo figcaption{
  position:relative;z-index:1;display:inline-block;
  font-family:var(--font-mono);font-size:.74rem;letter-spacing:.02em;
  color:var(--ink);background:#B4D5FE;          /* default text-selection highlight */
  padding:.18em .45em;margin-top:1.5rem;
}
.author-kicker{
  font-family:var(--font-display);font-weight:700;font-style:normal;
  font-size:1.2rem;color:var(--ink);border-left:3px solid var(--blue);
  padding-left:1.1rem;margin-top:2rem!important;
}

/* ============================ WAITLIST ============================ */
.waitlist{background:var(--wash);border-radius:0}
.waitlist-sub{max-width:54ch;margin-top:1.1rem;color:var(--muted)}
.waitlist-form{
  margin-top:2rem;display:flex;flex-wrap:wrap;gap:.8rem;max-width:34rem;
}
.waitlist-form input[type=email]{
  flex:1 1 16rem;font-family:var(--font-mono);font-size:1rem;
  padding:.95rem 1.1rem;border:2px solid var(--ink);border-radius:0;
  background:var(--paper);color:var(--ink);
}
.waitlist-form input[type=email]::placeholder{color:#9aa3ad}
.waitlist-form input[type=email]:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px var(--blue-wash)}
.waitlist-form .btn{flex:1 1 auto;justify-content:center}
.form-msg{font-family:var(--font-mono);font-size:.95rem;margin-top:1.4rem;padding:.9rem 1.1rem}
.form-ok{background:var(--blue);color:#fff}
.form-err{background:#fff;color:#b3261e;border:2px solid #b3261e}
.fineprint{font-family:var(--font-mono);font-size:.78rem;color:var(--muted);margin-top:1.1rem}

/* ============================ FAQ ============================ */
.faq details{border:0;border-bottom:1px solid var(--line)}
.faq details:first-of-type{border-top:1px solid var(--line);margin-top:1.8rem}
.faq summary{font-family:var(--font-display);font-weight:700;font-size:1.1rem;padding:1.25rem 0}
.faq summary::after{content:"+";font-size:1.4rem;line-height:1}
.faq details[open] summary::after{content:"\2212"}
.faq details p{padding:0 0 1.5rem;max-width:64ch;color:var(--muted)}

/* ============================ FOOTER CTA ============================ */
.foot-cta{text-align:center}
.foot-cta h2{margin:0 auto 2rem;max-width:20ch}
.foot-cta .btn{font-size:1.1rem}

/* ============================ FOOTER ============================ */
footer{
  max-width:var(--maxw);margin:0 auto;padding:var(--section-y) var(--gutter) 3rem;
  border-top:1px solid var(--line);
  font-family:var(--font-mono);font-size:.85rem;color:var(--muted);
}
.footer-mark{
  font-family:var(--font-display);font-weight:800;font-size:1.15rem;
  color:var(--blue);margin-bottom:1rem;letter-spacing:-.01em;
}
footer p{margin-bottom:.5rem}
.footer-links a{margin-right:.4rem}
.copyright{margin-top:1.2rem;opacity:.8}

/* ============================ ENTRANCE MOTION ============================ */
@media (prefers-reduced-motion:no-preference){
  [data-rise]{opacity:0;transform:translateY(18px);animation:rise .7s cubic-bezier(.2,.7,.3,1) forwards}
  [data-rise="1"]{animation-delay:.05s}
  [data-rise="2"]{animation-delay:.13s}
  [data-rise="3"]{animation-delay:.23s}
  [data-rise="4"]{animation-delay:.33s}
  [data-rise="5"]{animation-delay:.43s}
  [data-rise="6"]{animation-delay:.53s}
  .hero-cover img{animation:cover-in 1s cubic-bezier(.2,.7,.3,1) both;animation-delay:.3s}
  @keyframes rise{to{opacity:1;transform:none}}
  @keyframes cover-in{
    from{opacity:0;transform:rotateY(-22deg) rotateX(4deg) translateY(26px)}
    to{opacity:1;transform:rotateY(-9deg) rotateX(2.5deg)}
  }
}

/* ============================ RESPONSIVE ============================ */
@media (max-width:860px){
  .hero{grid-template-columns:1fr;min-height:auto;gap:2.5rem;padding-top:3rem}
  .hero-cover{order:-1}
  .hero-cover img{max-width:16rem;transform:rotateY(-6deg) rotateX(2deg)}
  h2{max-width:none}
  .grid{grid-template-columns:1fr}
  .toc{grid-template-columns:1fr;gap:1.4rem}
  .brace{font-size:42vh;opacity:.04}
  .author-grid{grid-template-columns:1fr;gap:2.5rem}
  .author-photo{max-width:18rem;margin-top:.5rem}
}
@media (max-width:520px){
  .brace{display:none}
  .hook{font-size:1.3rem}
  .waitlist-form .btn{flex:1 1 100%}
}