/* AlgoFuze — emerald design system */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');
/* General Sans via Fontshare */
@import url('https://api.fontshare.com/v2/css?f[]=general-sans@500,600,700&display=swap');

:root{
  --emerald:#065F46;
  --emerald-deep:#054533;
  --bone:#F5F5F4;
  --charcoal:#171717;
  --stone:#57534E;
  --amber:#D97706;
  --white:#FFFFFF;
  --line:rgba(6,95,70,0.14);
  --emerald-tint:rgba(6,95,70,0.05);
  --radius:8px;
  --maxw:1120px;
  --display:'General Sans','Inter',system-ui,sans-serif;
  --body:'Inter',system-ui,sans-serif;
  --mono:'JetBrains Mono',ui-monospace,monospace;
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:var(--body);
  color:var(--charcoal);
  background:var(--bone);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img,svg{max-width:100%;display:block}
a{color:inherit;text-decoration:none}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}

/* ---- type ---- */
h1,h2,h3{font-family:var(--display);font-weight:600;line-height:1.12;letter-spacing:-0.02em;color:var(--emerald)}
h1{font-size:clamp(2.1rem,5.2vw,3.6rem)}
h2{font-size:clamp(1.6rem,3.6vw,2.5rem)}
h3{font-size:clamp(1.15rem,2vw,1.4rem);letter-spacing:-0.01em}
p{font-size:1.0625rem}
.eyebrow{
  font-family:var(--mono);
  font-size:0.75rem;
  font-weight:500;
  letter-spacing:0.14em;
  text-transform:uppercase;
  color:var(--amber);
  margin-bottom:14px;
}
.lead{font-size:clamp(1.05rem,1.6vw,1.25rem);color:var(--stone);max-width:60ch}

/* ---- nav ---- */
.nav{position:sticky;top:0;z-index:50;background:rgba(245,245,244,0.86);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:66px}
.brand{font-family:var(--display);font-weight:700;font-size:1.22rem;color:var(--emerald);letter-spacing:-0.02em;display:flex;align-items:center;gap:9px}
.brand .dot{width:10px;height:10px;border-radius:50%;background:var(--amber);display:inline-block}
.nav-links{display:flex;align-items:center;gap:30px}
.nav-links a{font-size:0.95rem;font-weight:500;color:var(--stone);transition:color .15s}
.nav-links a:hover{color:var(--emerald)}
.nav-cta{background:var(--emerald);color:var(--bone)!important;padding:9px 17px;border-radius:var(--radius);font-size:0.9rem!important;font-weight:600;transition:background .15s}
.nav-cta:hover{background:var(--emerald-deep)}
.nav-toggle{display:none;background:none;border:none;cursor:pointer;font-size:1.5rem;color:var(--emerald)}

/* ---- buttons ---- */
.btn{display:inline-flex;align-items:center;gap:9px;font-weight:600;font-size:1rem;padding:14px 26px;border-radius:var(--radius);transition:all .16s;cursor:pointer;border:none;font-family:var(--body)}
.btn-primary{background:var(--amber);color:var(--white)}
.btn-primary:hover{background:#b8620a;transform:translateY(-1px)}
.btn-emerald{background:var(--emerald);color:var(--bone)}
.btn-emerald:hover{background:var(--emerald-deep);transform:translateY(-1px)}
.btn-ghost{background:transparent;color:var(--emerald);border:1px solid var(--line)}
.btn-ghost:hover{border-color:var(--emerald);background:var(--emerald-tint)}

/* ---- sections ---- */
section{padding:84px 0}
.section-tight{padding:60px 0}
.center{text-align:center}
.divider{height:1px;background:var(--line);border:none}

/* ---- hero ---- */
.hero{padding:76px 0 64px}
.hero h1{max-width:16ch}
.hero .lead{margin:22px 0 32px;font-size:clamp(1.08rem,1.7vw,1.3rem)}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap;align-items:center}
.hero-note{font-family:var(--mono);font-size:0.78rem;color:var(--stone);margin-top:18px;letter-spacing:0.02em}

/* ---- diagram frame ---- */
.diagram-wrap{background:var(--white);border:1px solid var(--line);border-radius:14px;padding:30px 24px;margin-top:14px;box-shadow:0 1px 3px rgba(6,95,70,0.04)}
.diagram-cap-top{font-family:var(--display);font-weight:600;font-size:1.35rem;color:var(--emerald);text-align:center;margin-bottom:6px}
.diagram-cap-bottom{text-align:center;color:var(--stone);max-width:58ch;margin:16px auto 0;font-size:0.98rem}

/* ---- problem ---- */
.problem{background:var(--emerald);color:var(--bone)}
.problem h2{color:var(--bone)}
.problem p{color:rgba(245,245,244,0.9);max-width:64ch;margin-top:20px;font-size:1.12rem}
.problem p + p{margin-top:18px}
.problem .kicker{color:var(--bone);font-weight:600;font-family:var(--display);font-size:1.15rem;margin-top:24px}

/* ---- phases ---- */
.phase-grid{display:flex;flex-direction:column;gap:0;margin-top:40px;border-top:1px solid var(--line)}
.phase{display:grid;grid-template-columns:120px 1fr;gap:28px;padding:26px 0;border-bottom:1px solid var(--line);align-items:start}
.phase-num{font-family:var(--mono);font-size:0.82rem;font-weight:600;color:var(--amber);letter-spacing:0.06em;padding-top:4px}
.phase-num .free{display:inline-block;margin-top:6px;color:var(--emerald);background:var(--emerald-tint);padding:2px 8px;border-radius:100px;font-size:0.72rem}
.phase h3{margin-bottom:7px}
.phase p{color:var(--stone);font-size:1.02rem}

/* ---- feature grid ---- */
.grid{display:grid;gap:24px}
.grid-2{grid-template-columns:repeat(2,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.card{background:var(--white);border:1px solid var(--line);border-radius:12px;padding:26px;transition:border-color .16s,transform .16s}
.card:hover{border-color:rgba(6,95,70,0.3);transform:translateY(-2px)}
.card h3{margin-bottom:9px;font-size:1.18rem}
.card p{color:var(--stone);font-size:0.98rem}
.card .tag{font-family:var(--mono);font-size:0.72rem;color:var(--amber);letter-spacing:0.08em;text-transform:uppercase;display:block;margin-bottom:12px}

/* ---- diff rows ---- */
.diff{display:grid;grid-template-columns:repeat(2,1fr);gap:20px;margin-top:38px}
.diff-item{padding:24px;border:1px solid var(--line);border-radius:12px;background:var(--white)}
.diff-item h3{font-size:1.1rem;margin-bottom:8px}
.diff-item p{color:var(--stone);font-size:0.97rem}

/* ---- industries ---- */
.industries{background:var(--emerald-tint)}
.industries .lead{margin:18px auto 0;text-align:center}

/* ---- tools strip ---- */
.tools{text-align:center}
.tools-row{display:flex;flex-wrap:wrap;justify-content:center;gap:14px 26px;margin:26px 0 18px}
.tool-chip{font-family:var(--mono);font-size:0.92rem;font-weight:500;color:var(--emerald);padding:8px 16px;border:1px solid var(--line);border-radius:100px;background:var(--white)}
.tools .lead{margin:0 auto;text-align:center;font-size:1rem}

/* ---- founder teaser ---- */
.founder{display:grid;grid-template-columns:180px 1fr;gap:36px;align-items:center}
.founder-photo{width:180px;height:180px;border-radius:14px;background:var(--emerald-tint);border:1px solid var(--line);display:flex;align-items:center;justify-content:center;font-family:var(--mono);font-size:0.75rem;color:var(--stone);text-align:center;padding:12px}
.founder p{font-size:1.15rem;color:var(--charcoal)}
.founder .sig{font-family:var(--mono);font-size:0.85rem;color:var(--stone);margin-top:14px}

/* ---- big cta ---- */
.cta-band{background:var(--emerald);color:var(--bone);text-align:center}
.cta-band h2{color:var(--bone)}
.cta-band p{color:rgba(245,245,244,0.9);max-width:56ch;margin:18px auto 30px;font-size:1.1rem}

/* ---- about ---- */
.prose{max-width:70ch}
.prose h2{margin:44px 0 16px}
.prose h2:first-child{margin-top:0}
.prose p{margin-bottom:18px;color:var(--charcoal);font-size:1.1rem}
.prose .eyebrow{margin-top:0}
.about-actions{display:flex;gap:14px;flex-wrap:wrap;margin-top:34px}

/* ---- book ---- */
.book-grid{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:start}
.book-steps{list-style:none;counter-reset:step;margin-top:26px}
.book-steps li{counter-increment:step;padding:16px 0 16px 52px;position:relative;border-bottom:1px solid var(--line);color:var(--stone)}
.book-steps li::before{content:counter(step);position:absolute;left:0;top:14px;width:34px;height:34px;background:var(--emerald-tint);color:var(--emerald);border-radius:50%;display:flex;align-items:center;justify-content:center;font-family:var(--mono);font-weight:600;font-size:0.95rem}
.book-steps li strong{color:var(--charcoal);display:block;font-size:1.05rem}
.embed-frame{border:1px solid var(--line);border-radius:12px;overflow:hidden;background:var(--white);min-height:640px}
.embed-placeholder{padding:40px;text-align:center;color:var(--stone);font-family:var(--mono);font-size:0.85rem}

/* ---- page header ---- */
.page-head{padding:70px 0 40px}
.page-head .lead{margin-top:18px}

/* ---- footer ---- */
.footer{background:var(--emerald-deep);color:rgba(245,245,244,0.75);padding:54px 0 30px}
.footer a{color:rgba(245,245,244,0.75);transition:color .15s}
.footer a:hover{color:var(--bone)}
.footer-top{display:flex;justify-content:space-between;flex-wrap:wrap;gap:30px;padding-bottom:30px;border-bottom:1px solid rgba(245,245,244,0.14)}
.footer-brand{font-family:var(--display);font-weight:700;font-size:1.3rem;color:var(--bone);display:flex;align-items:center;gap:9px}
.footer-brand .dot{width:9px;height:9px;border-radius:50%;background:var(--amber)}
.footer-links{display:flex;gap:40px;flex-wrap:wrap}
.footer-col h4{font-family:var(--mono);font-size:0.72rem;letter-spacing:0.1em;text-transform:uppercase;color:rgba(245,245,244,0.5);margin-bottom:12px;font-weight:500}
.footer-col a{display:block;font-size:0.95rem;margin-bottom:8px}
.footer-bottom{padding-top:24px;font-size:0.85rem;font-family:var(--mono);color:rgba(245,245,244,0.5)}

/* ---- responsive ---- */
@media(max-width:860px){
  .nav-links{position:fixed;inset:66px 0 auto 0;background:var(--bone);flex-direction:column;align-items:stretch;gap:0;padding:8px 24px 20px;border-bottom:1px solid var(--line);display:none}
  .nav-links.open{display:flex}
  .nav-links a{padding:13px 0;border-bottom:1px solid var(--line)}
  .nav-cta{text-align:center;margin-top:10px}
  .nav-toggle{display:block}
  .grid-4{grid-template-columns:repeat(2,1fr)}
  .diff{grid-template-columns:1fr}
  .book-grid{grid-template-columns:1fr;gap:32px}
  .founder{grid-template-columns:1fr;text-align:center}
  .founder-photo{margin:0 auto}
  .phase{grid-template-columns:88px 1fr;gap:18px}
}
@media(max-width:520px){
  .grid-4,.grid-2{grid-template-columns:1fr}
  section{padding:60px 0}
  .hero-cta{flex-direction:column;align-items:stretch}
  .hero-cta .btn{justify-content:center}
}
@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}