:root{
    --bg:var(--gray-0); --bg-2:var(--gray-20); --panel:var(--gray-0);
    --text:var(--gray-750); --text-2:var(--gray-500); --text-3:var(--gray-300);
    --brand:var(--violet-400);
    --line:color-mix(in srgb, var(--gray-900) 8%, transparent); --line-strong:color-mix(in srgb, var(--gray-900) 13%, transparent);
    --shadow-float:0 0 0 1px color-mix(in srgb, var(--gray-900) 5%, transparent), 0 2px 6px color-mix(in srgb, var(--gray-900) 5%, transparent), 0 12px 32px color-mix(in srgb, var(--gray-900) 10%, transparent);
    --ease-exit:cubic-bezier(.215,.61,.355,1);
    --ease-out:cubic-bezier(.16,1,.3,1);
    --ease-spring:cubic-bezier(.34,1.26,.64,1);
    --ok:var(--green-300);
  }
  html[data-theme="dark"]{
    --bg:var(--gray-900); --bg-2:var(--gray-880); --panel:var(--gray-870);
    --text:var(--gray-20); --text-2:var(--gray-350); --text-3:var(--gray-550);
    --brand:var(--violet-450);
    --line:color-mix(in srgb, var(--gray-0) 8%, transparent); --line-strong:color-mix(in srgb, var(--gray-0) 15%, transparent);
    --shadow-float:0 0 0 1px color-mix(in srgb, var(--gray-0) 8%, transparent), 0 2px 6px color-mix(in srgb, var(--gray-900) 40%, transparent), 0 12px 32px color-mix(in srgb, var(--gray-900) 55%, transparent);
  }
  *{margin:0;padding:0;box-sizing:border-box}
  html{color-scheme:light dark}
  body{
    font-family:var(--font);
    font-feature-settings:"cv01","ss03";
    background:var(--bg); color:var(--text);
    -webkit-font-smoothing:antialiased;
    overflow-x:hidden;
  }
  button{font:inherit;color:inherit;background:none;border:0;cursor:default}
  a{color:inherit;text-decoration:none}
  ::selection{background:color-mix(in srgb, var(--brand) 25%, transparent)}
  .tab{font-variant-numeric:tabular-nums}
  .mono{font-family:var(--font-mono)}

  .stub{max-width:1080px;margin:0 auto;padding:150px 24px 90px}
  .stub h1{font-size:clamp(40px,4.6vw,56px);font-weight:500;letter-spacing:-0.022em;line-height:1.06;max-width:16ch}
  .stub p{margin-top:16px;font-size:15px;line-height:1.55;color:var(--text-2);max-width:52ch}
  .stub section{margin-top:70px;height:36vh;border-radius:12px;background:var(--bg-2);box-shadow:inset 0 0 0 1px var(--line);display:grid;place-items:center;color:var(--text-3);font-size:13px;font-weight:550}

  .f-base{display:flex;align-items:center;gap:22px;flex-wrap:wrap;padding:18px 0 0;margin-top:26px;border-top:1px solid var(--line);font-size:12px;color:var(--text-3)}
  .f-base a{color:var(--text-2);font-weight:500}
  .f-base a:is(:hover, [data-hover]){color:var(--text)}
  .f-base .sp{flex:1}
  /* =========================================================
     D · FOLD — the letter unfolds
     ========================================================= */
  #rd-foot{padding:80px 24px 40px;display:grid;place-items:center;perspective:1400px}
  #rd-paper{width:min(760px,92vw)}
  .fold-p{
    background:var(--panel);
    box-shadow:0 0 0 1px var(--line);
    transform-origin:top center;
    transform:rotateX(-89deg);
    position:relative;
    transition:transform .8s var(--ease-out) var(--fd,0s);
    transform-style:preserve-3d;
  }
  .fold-p .shade{
    position:absolute;inset:0;background:linear-gradient(180deg, color-mix(in srgb, var(--gray-900) 28%, transparent), color-mix(in srgb, var(--gray-900) 0%, transparent) 70%);
    opacity:1;pointer-events:none;
    transition:opacity .8s var(--ease-out) var(--fd,0s);
  }
  #rd-foot.open .fold-p{transform:rotateX(0)}
  #rd-foot.open .fold-p .shade{opacity:0}
  .fp1{padding:26px 30px;display:flex;align-items:baseline;justify-content:space-between}
  .fp1 b{font-size:24px;font-weight:550;letter-spacing:-.5px}
  .fp1 span{font-size:12px;color:var(--text-3)}
  .fp2{padding:22px 30px;display:grid;grid-template-columns:repeat(4,1fr);gap:18px;border-top:1px dashed var(--line-strong)}
  .fp2 h6{font-size:9px;font-weight:550;text-transform:none;letter-spacing:.5px;color:var(--text-3);margin-bottom:8px}
  .fp2 a{display:block;font-size:13px;font-weight:500;color:var(--text-2);padding:3px 0}
  .fp2 a:is(:hover, [data-hover]){color:var(--text)}
  .fp3{padding:16px 30px;display:flex;font-size:12px;color:var(--text-3);border-top:1px dashed var(--line-strong)}
  .fp3 .sp{flex:1}
  #rd-again{margin-top:22px;font-size:12px;font-weight:550;color:var(--text-2);border:1px solid var(--line-strong);border-radius:99px;padding:7px 15px}
  #rd-again:is(:hover, [data-hover]){color:var(--text)}

  @media (prefers-reduced-motion: reduce){
    *{transition-duration:.01ms !important;animation-duration:.01ms !important}
  }
body { font-size: 15px; line-height: normal; }