/* Modeled on linear.app/method: near-black page, 688px column, serif display titles,
   Inter body, mono numbers, dashed rules, one line illustration per chapter.
   Body text stays light (#d0d6e0); no gray text. */
:root{
  --bg:#08090a;--fg:#f7f8f8;--text:#d0d6e0;--line:#1f2023;--dash:#3e3e44;--dim:#5e6168;--card:#0f1011;
  --serif:Newsreader,Georgia,serif;
  --sans:Inter,"IBM Plex Sans Thai",-apple-system,"Segoe UI",sans-serif;
  --thai:"IBM Plex Sans Thai",Inter,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,monospace;
}
*{margin:0;padding:0;box-sizing:border-box}
body{background:var(--bg);color:var(--text);font-family:var(--sans);font-size:17px;line-height:1.6;-webkit-font-smoothing:antialiased}
html{scroll-padding-top:88px}
a{color:inherit;text-decoration:none}
::selection{background:#f7f8f833}

/* Header */
.top{position:sticky;top:0;z-index:10;background:rgba(8,9,10,.8);backdrop-filter:saturate(180%) blur(16px);-webkit-backdrop-filter:saturate(180%) blur(16px);border-bottom:1px solid var(--line)}
.top .in{max-width:1200px;margin:0 auto;padding:0 32px;height:72px;display:flex;align-items:center;justify-content:space-between}
.brand{color:var(--fg);font-weight:600;font-size:18px;letter-spacing:-.02em}
.top nav{display:flex;align-items:center;gap:28px;font-size:14px}
.top nav a{transition:color .15s}
.top nav a:hover{color:var(--fg)}
.pill{display:inline-block;background:var(--fg);color:var(--bg);font-size:14px;font-weight:500;padding:7px 14px;border-radius:999px;transition:opacity .15s}
.pill:hover{opacity:.88}

.col{max-width:752px;margin:0 auto;padding:0 32px}

/* Cover */
.hero{text-align:center;padding:120px 32px 0}
.kicker{font-size:13px;letter-spacing:.04em;text-transform:uppercase;margin-bottom:28px}
.hero h1{font-family:var(--serif);font-weight:400;color:var(--fg);font-size:128px;line-height:1;letter-spacing:-.025em}
.hero .sub{max-width:520px;text-wrap:balance;margin:36px auto 0;font-family:var(--thai);line-height:1.8}
.hero .cta{margin-top:36px}
.hero > *{animation:rise .9s cubic-bezier(.2,.7,.2,1) both}
.hero > *:nth-child(2){animation-delay:.08s}
.hero > *:nth-child(3){animation-delay:.16s}
.hero > *:nth-child(4){animation-delay:.24s}
@keyframes rise{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}

.venn{display:block;width:100%;max-width:1000px;height:auto;margin:96px auto 0;animation:fade 1.6s .3s both}
@keyframes fade{from{opacity:0}to{opacity:1}}

/* Contents */
.contents{padding-top:112px;padding-bottom:96px}
.group{padding:28px 0;border-top:1px dashed var(--dash)}
.group:first-child{border-top:0;padding-top:0}
.label{color:var(--fg);font-size:13px;font-weight:600;letter-spacing:.02em;text-transform:uppercase;margin-bottom:14px}
.toc{list-style:none}
.toc a{display:flex;justify-content:space-between;align-items:baseline;padding:4px 0;transition:color .15s}
.toc a:hover{color:var(--fg)}
.toc .n{font-family:var(--mono);font-size:14px;letter-spacing:.06em}

/* Home (lztakuo.com): one screen, no scrolling, like Dan Koe's letters signup */
body.home{height:100vh;height:100dvh;overflow:hidden;display:flex;flex-direction:column}
body.home .top{position:relative;flex:none}
body.home main{flex:1;min-height:0;position:relative;display:flex;align-items:center;justify-content:center;overflow:hidden}
body.home .hero{padding:0 32px;position:relative;z-index:1}
body.home .venn{position:absolute;left:50%;top:50%;width:min(1100px,150vw);margin:0;transform:translate(-50%,-50%);z-index:0;pointer-events:none;animation:fadeLow 1.6s .3s both}
@keyframes fadeLow{from{opacity:0}to{opacity:.3}}
@media (max-height:760px){body.home .hero h1{font-size:96px}body.home .kicker{margin-bottom:18px}}
@media (max-width:760px){body.home .hero{padding:0 16px}body.home .hero h1{font-size:56px}}

/* Free page */
.hero.free .signup{margin:36px auto 0}
.hero.free .signup-msg{margin-top:36px}
.hero .note{font-family:var(--thai);font-size:14px;margin-top:16px}
.foot-space{height:120px}

/* Email signup */
.subscribe{padding-top:0;padding-bottom:160px}
.subscribe h2{font-family:var(--serif);font-weight:400;color:var(--fg);font-size:48px;line-height:1.05;letter-spacing:-.02em;margin-bottom:16px}
.subscribe .th{font-family:var(--thai);line-height:1.8;margin-bottom:28px;text-wrap:pretty}
.signup{display:flex;gap:10px;max-width:480px}
.signup[hidden]{display:none}
.signup input{flex:1;background:var(--card);border:1px solid var(--line);border-radius:999px;color:var(--fg);font:15px var(--thai);padding:10px 18px;outline:none}
.signup input:focus{border-color:var(--dash)}
.signup .pill{border:0;cursor:pointer;font-family:var(--thai)}
.signup .pill:disabled{opacity:.6}
.signup-msg{font-family:var(--thai);color:var(--fg);line-height:1.8}
.signup input::placeholder{color:var(--text);opacity:.7}

/* Chapter */
.page{padding-top:72px}
.crumb{display:flex;gap:8px;font-size:14px}
.crumb a:hover{color:var(--fg)}
.page h1{font-family:var(--serif);font-weight:400;color:var(--fg);font-size:72px;line-height:1;letter-spacing:-.022em;margin-top:20px}
.art{display:block;width:100%;height:auto;margin:64px 0;overflow:visible}
.prose p{font-family:var(--thai);line-height:1.85;margin-bottom:22px;text-wrap:pretty}
.prose p:last-child{margin-bottom:0}

.facts{list-style:none;margin:56px 0 0;border-top:1px dashed var(--dash)}
.facts li{display:flex;justify-content:space-between;padding:14px 0;border-bottom:1px dashed var(--dash);font-family:var(--thai)}
.facts b{color:var(--fg);font-weight:500}
.buy{margin-top:36px}
.pill.big{font-size:16px;padding:12px 24px}

.pager{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:72px 0 160px}
.card{display:block;padding:16px 18px;border:1px solid var(--line);border-radius:10px;background:var(--bg);transition:border-color .15s,background .15s}
.card:hover{border-color:var(--dash);background:var(--card)}
.card small{display:block;font-size:13px;margin-bottom:4px}
.card small b{font-family:var(--mono);font-weight:400;margin-left:6px}
.card span{color:var(--fg);font-size:15px;font-weight:500}
.card.next{text-align:right;grid-column:2}

@media (max-width:760px){
  .top .in,.col{padding-left:16px;padding-right:16px}
  .top nav .hide-m{display:none}
  .hero{padding:72px 16px 0}
  .hero h1{font-size:60px}
  .venn{margin-top:56px}
  .contents{padding-top:72px;padding-bottom:96px}
  .page{padding-top:48px}
  .page h1{font-size:44px}
  .art{margin:40px 0}
  .pager{grid-template-columns:1fr;margin-bottom:96px}
  .card.next{grid-column:auto}
}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}