:root {
  --bg: #fbfbf9;
  --ink: #17171a;
  --sub: #6e6e73;
  --hairline: rgba(23, 23, 26, 0.1);
  --gold: #b8934a;
  --gold-soft: rgba(184, 147, 74, 0.16);
  --radius: 18px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
.wrap { max-width: 1060px; margin: 0 auto; padding: 0 28px; }

/* header */
header {
  position: absolute; top: 0; left: 0; right: 0; z-index: 10;
  display: flex; justify-content: space-between; align-items: center;
  padding: 28px 36px;
}
.mark { display: flex; align-items: center; gap: 10px; font-weight: 600; letter-spacing: -0.01em; text-decoration: none; color: var(--ink); font-size: 17px; }
.mark svg { display: block; }
.byline { font-size: 13px; color: var(--sub); text-decoration: none; }
.byline:hover { color: var(--ink); }

/* type */
.eyebrow {
  font-size: 12px; font-weight: 600; letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--gold); margin-bottom: 22px;
}
h1.display {
  font-size: clamp(44px, 7.2vw, 84px);
  line-height: 1.02; letter-spacing: -0.035em; font-weight: 650;
}
.lede { font-size: clamp(18px, 2.2vw, 22px); color: var(--sub); max-width: 620px; margin: 28px auto 0; }
h2 { font-size: clamp(30px, 4vw, 44px); letter-spacing: -0.03em; line-height: 1.1; font-weight: 650; }
h3 { font-size: 19px; letter-spacing: -0.015em; font-weight: 600; }
.sub { color: var(--sub); }
section p.body { color: var(--sub); max-width: 640px; }

/* hero */
.hero { min-height: 92vh; display: flex; flex-direction: column; justify-content: center; align-items: center; text-align: center; padding: 140px 24px 80px; position: relative; }
.venn { margin-bottom: 44px; }
.venn .drift-l { animation: driftL 9s ease-in-out infinite alternate; }
.venn .drift-r { animation: driftR 9s ease-in-out infinite alternate; }
.venn .lens { animation: breathe 9s ease-in-out infinite alternate; }
@keyframes driftL { from { transform: translateX(0); } to { transform: translateX(7px); } }
@keyframes driftR { from { transform: translateX(0); } to { transform: translateX(-7px); } }
@keyframes breathe { from { opacity: 0.55; } to { opacity: 1; } }
@media (prefers-reduced-motion: reduce) {
  .venn .drift-l, .venn .drift-r, .venn .lens { animation: none; }
  .reveal { opacity: 1 !important; transform: none !important; }
}

/* buttons */
.actions { display: flex; gap: 14px; margin-top: 40px; flex-wrap: wrap; justify-content: center; }
.btn {
  display: inline-block; padding: 14px 30px; border-radius: 999px;
  background: var(--ink); color: #fff; text-decoration: none; font-weight: 600; font-size: 16px;
  border: 1px solid var(--ink); transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.btn:hover { transform: translateY(-1px); box-shadow: 0 10px 30px rgba(23,23,26,0.14); }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--hairline); }
.btn.ghost:hover { border-color: var(--ink); box-shadow: none; }
.btn[disabled] { opacity: 0.45; pointer-events: none; }

/* sections */
section.block { padding: 110px 0; }
.rule { border: 0; border-top: 1px solid var(--hairline); }
.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 56px; margin-top: 64px; }
@media (max-width: 780px) { .grid3 { grid-template-columns: 1fr; gap: 40px; } }
.step .num { font-size: 13px; font-weight: 600; color: var(--gold); letter-spacing: 0.18em; margin-bottom: 14px; }
.step p { color: var(--sub); margin-top: 10px; font-size: 16px; }

.chips { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }
.chip {
  padding: 10px 22px; border: 1px solid var(--hairline); border-radius: 999px;
  font-size: 15px; font-weight: 500; color: var(--ink); background: #fff;
}

.quiet {
  background: #fff; border-top: 1px solid var(--hairline); border-bottom: 1px solid var(--hairline);
}
.quiet .inner { max-width: 720px; margin: 0 auto; text-align: center; }

/* reveal on scroll */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in { opacity: 1; transform: none; }

/* footer */
footer { padding: 56px 36px; display: flex; justify-content: space-between; align-items: center; color: var(--sub); font-size: 13px; flex-wrap: wrap; gap: 12px; }
footer a { color: var(--sub); }
footer a:hover { color: var(--ink); }

/* ---- private session page ---- */
.session { max-width: 720px; margin: 0 auto; padding: 150px 28px 120px; }
.session-head { text-align: center; margin-bottom: 72px; }
.prepared { margin-top: 18px; font-size: 15px; color: var(--sub); }
.prepared strong { color: var(--ink); font-weight: 600; }
.card {
  background: #fff; border: 1px solid var(--hairline); border-radius: var(--radius);
  padding: 40px; margin-bottom: 28px;
}
.card h3 { margin-bottom: 12px; }
.card p { color: var(--sub); font-size: 16px; }
.card p + p { margin-top: 12px; }
.card .body-link { color: var(--ink); font-weight: 500; }
ol.steps { margin: 20px 0 0 20px; color: var(--ink); }
ol.steps li { margin-bottom: 14px; color: var(--sub); font-size: 16px; }
ol.steps li strong { color: var(--ink); font-weight: 600; }
.tip {
  background: var(--gold-soft); border-radius: 12px; padding: 16px 20px; margin-top: 22px;
  font-size: 15px; color: var(--ink);
}
.drop {
  border: 1.5px dashed rgba(23,23,26,0.25); border-radius: 14px; padding: 44px 24px;
  text-align: center; color: var(--sub); cursor: pointer; transition: border-color 0.15s, background 0.15s;
  margin-top: 22px; font-size: 16px;
}
.drop.over { border-color: var(--gold); background: var(--gold-soft); }
.drop .filename { color: var(--ink); font-weight: 600; }
.field { width: 100%; margin-top: 16px; padding: 13px 16px; font-size: 16px; border: 1px solid var(--hairline); border-radius: 12px; background: #fff; color: var(--ink); font-family: inherit; }
.field:focus { outline: none; border-color: var(--ink); }
.upload-actions { margin-top: 20px; display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.status { font-size: 15px; color: var(--sub); }
.status.ok { color: #2e7d4f; font-weight: 600; }
.status.err { color: #b3402e; font-weight: 600; }
.sealed { text-align: center; padding: 30px 10px 6px; }
.sealed h3 { font-size: 26px; letter-spacing: -0.02em; }
.sealed p { color: var(--sub); margin-top: 10px; }
.footnote { text-align: center; color: var(--sub); font-size: 14px; margin-top: 40px; }