/* ============================================================
   TECH GRAVITY — site stylesheet
   Source of truth: apps/techgravity-site-draft-v3.html (2026-07-19 定稿)
   Tokens lifted verbatim; deviations logged in docs/DECISIONS.md
   ============================================================ */

/* ================= DESIGN TOKENS ================= */
:root{
  --font-ui:'Inter',ui-sans-serif,system-ui,-apple-system,sans-serif;
  --font-display:'Instrument Serif',Georgia,serif;
  --font-mono:'JetBrains Mono',ui-monospace,'SF Mono',monospace;

  --bg:#fbfbfb;
  --bg-deep:#f1f1ef;
  --panel:#ffffff;
  --panel-hi:#ffffff;
  --line:rgba(17,17,17,.08);
  --line-strong:rgba(17,17,17,.18);
  --text:#171717;
  --dim:#666666;
  --faint:#a3a3a3;
  --accent:#0f4bf1;
  --shadow:0 18px 50px -22px rgba(20,25,35,.18);

  /* per-product accents */
  --sudoku:#6c63ff;
  --tare:#0aa658;
  --zen:#c25232;
}
/* SPACE theme — follows system preference (draft's THEME toggle was a
   reviewer-rig control; production follows prefers-color-scheme) */
@media (prefers-color-scheme: dark){
  :root{
    --bg:#0b0d14;
    --bg-deep:#070810;
    --panel:#12141d;
    --panel-hi:#181b26;
    --line:rgba(255,255,255,.08);
    --line-strong:rgba(255,255,255,.17);
    --text:#eceded;
    --dim:#9aa0a6;
    --faint:#5c6167;
    --accent:#7b9dff;
    --shadow:0 20px 60px -20px rgba(0,0,0,.6);
    --sudoku:#8b7bff;
    --tare:#35e07f;
    --zen:#d96c45;
  }
}

/* ================= BASE ================= */
*{margin:0;padding:0;box-sizing:border-box}
html,body{height:100%}
body{
  font-family:var(--font-ui);background:var(--bg);color:var(--text);
  font-size:15px;line-height:1.6;-webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:none;cursor:pointer}
.mono{font-family:var(--font-mono);font-feature-settings:"tnum"}

/* ================= SITE CHROME ================= */
.wrap{max-width:1020px;margin:0 auto;padding:0 32px}
.nav{display:flex;align-items:center;height:64px}
.brand{font-family:var(--font-mono);font-size:12px;font-weight:500;letter-spacing:.34em;display:flex;align-items:center;gap:12px}
.brand .mark{width:26px;height:26px;color:var(--text);flex:none}
.brand:hover .mark{color:var(--accent)}
.brand i{font-style:normal;opacity:.4;margin:0 1px}
.nav .links{margin-left:auto;display:flex;gap:26px;font-size:13px;color:var(--dim)}
.nav .links a:hover{color:var(--accent)}
.sitefoot{border-top:1px solid var(--line);margin-top:90px}
.sitefoot .in{display:flex;align-items:baseline;gap:22px;padding:26px 0 34px;font-family:var(--font-mono);font-size:10.5px;color:var(--faint);flex-wrap:wrap}
.sitefoot a:hover{color:var(--accent)}
.sitefoot .r{margin-left:auto}

/* ================= HOME ================= */
.hero{padding:72px 0 84px;display:flex;align-items:center;gap:40px}
.hero .txt{flex:1;min-width:0}
.hero .eyebrow{font-family:var(--font-mono);font-size:10px;letter-spacing:.3em;color:var(--faint);margin-bottom:22px}
.hero h1{font-family:var(--font-display);font-size:58px;line-height:1.04;letter-spacing:-.01em;font-weight:400;max-width:13em}
.hero h1 .q{color:var(--dim);font-style:italic}
.hero .sub{margin-top:22px;max-width:34em;color:var(--dim);font-size:16px;line-height:1.7}
.hero .meta{margin-top:30px;font-family:var(--font-mono);font-size:10.5px;letter-spacing:.18em;color:var(--faint)}
.hero .meta i{font-style:normal;margin:0 10px;opacity:.4}

.sec-label{font-family:var(--font-mono);font-size:10px;letter-spacing:.3em;color:var(--faint);
  padding-bottom:14px;border-bottom:1px solid var(--line);margin-bottom:0}
.cards{display:flex;flex-direction:column}
.pcard{
  display:flex;align-items:center;gap:30px;padding:34px 6px;
  border-bottom:1px solid var(--line);position:relative;transition:background .2s;
}
.pcard:hover{background:var(--panel)}
.pcard .glyph{
  width:84px;height:84px;flex:none;border-radius:20px;
  display:flex;align-items:center;justify-content:center;
  border:1px solid var(--line-strong);background:var(--panel-hi);
  position:relative;overflow:hidden;
}
.pcard .body{flex:1;min-width:0}
.pcard .name{font-size:21px;font-weight:650;letter-spacing:-.015em;display:flex;align-items:baseline;gap:12px}
.pcard .name .plat{font-family:var(--font-mono);font-size:9px;letter-spacing:.18em;color:var(--dim);border:1px solid var(--line-strong);border-radius:20px;padding:3px 9px 3px 6px;transform:translateY(-2px);display:inline-flex;align-items:center;gap:6px}
.plat .g{display:inline-block;width:10px;height:10px;flex:none}
.plat.ios .g{border:1.4px solid currentColor;border-radius:3.5px;width:9px;height:9px}
.plat.chrome .g{border-radius:50%;background:radial-gradient(circle,#4285f4 0 26%,var(--panel-hi) 26% 38%,transparent 38%),conic-gradient(from -30deg,#ea4335 0 120deg,#fbbc05 0 240deg,#34a853 0 360deg)}
.plat.ios{border-radius:7px}
.pcard .desc{color:var(--dim);margin-top:6px;max-width:36em}
.pcard .cta{flex:none;display:flex;flex-direction:column;align-items:flex-end;gap:8px}
.btn{
  font-size:13px;font-weight:550;border:1px solid var(--line-strong);
  border-radius:8px;padding:9px 16px;display:inline-flex;align-items:center;gap:8px;
}
.btn:hover{border-color:var(--dim)}
.btn.solid{background:#111;color:#fff;border-color:#111}
@media (prefers-color-scheme: dark){
  .btn.solid{background:var(--text);color:var(--bg);border-color:var(--text)}
}
.pstat{font-family:var(--font-mono);font-size:9.5px;letter-spacing:.16em;color:var(--faint)}
.pstat .dot{display:inline-block;width:6px;height:6px;border-radius:50%;margin-right:6px;vertical-align:1px}

/* ---- orbital diagram ---- */
.orbit-wrap{flex:none;width:380px;height:380px;position:relative}
.ring{position:absolute;border-radius:50%;border:1px solid var(--line-strong)}
.ring.dashed{border-style:dashed;opacity:.8}
.r1{inset:118px}
.r2{inset:64px}
.r3{inset:10px}
.spin{position:absolute;inset:0;animation:spin linear infinite}
.spin.s1{animation-duration:48s;animation-delay:-9s}
.spin.s2{animation-duration:86s;animation-delay:-38s}
.spin.s3{animation-duration:130s;animation-direction:reverse;animation-delay:-71s}
@keyframes spin{to{transform:rotate(360deg)}}
.body-dot{
  position:absolute;top:0;left:50%;transform:translate(-50%,-50%);
  width:34px;height:34px;border-radius:50%;
  background:var(--panel-hi);border:1px solid var(--line-strong);
  display:flex;align-items:center;justify-content:center;
  box-shadow:0 0 0 6px var(--bg);
}
.spin.s1 .body-dot{top:118px}
.spin.s2 .body-dot{top:64px}
.spin.s3 .body-dot{top:10px}
.counter{display:flex;align-items:center;justify-content:center;width:100%;height:100%;animation:spin linear infinite reverse}
.spin.s1 .counter{animation-duration:48s;animation-delay:-9s}
.spin.s2 .counter{animation-duration:86s;animation-delay:-38s}
.spin.s3 .counter{animation-duration:130s;animation-direction:normal;animation-delay:-71s}
.body-dot .m{display:block;width:13px;height:13px;border-radius:3px}
.center-mass{
  position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);
  width:72px;height:72px;border-radius:50%;
  background:var(--panel-hi);border:1px solid var(--line-strong);
  display:flex;align-items:center;justify-content:center;
  box-shadow:0 0 0 10px var(--bg),var(--shadow);
}
.center-mass svg{width:40px;height:40px;color:var(--text)}
.orbit-cap{position:absolute;left:50%;bottom:-28px;transform:translateX(-50%);
  font-family:var(--font-mono);font-size:9px;letter-spacing:.24em;color:var(--faint);white-space:nowrap}
@media (prefers-reduced-motion: reduce){
  .spin,.counter{animation:none}
}
/* orbit index on product rows */
.pcard .orbidx{flex:none;width:86px;font-family:var(--font-mono);font-size:9.5px;letter-spacing:.16em;color:var(--faint);line-height:1.9}
.pcard .orbidx b{display:block;color:var(--dim);font-weight:400}
/* sudoku pixel glyph */
.g-sudoku{display:grid;grid-template-columns:repeat(5,8px);grid-template-rows:repeat(5,8px);gap:2px}
.g-sudoku i{background:var(--sudoku);opacity:.25;border-radius:1px}
.g-sudoku i.f{opacity:1}
/* tare reticle glyph */
.g-tare{width:44px;height:44px;position:relative}
.g-tare::before,.g-tare::after{content:"";position:absolute;background:var(--tare)}
.g-tare::before{left:50%;top:0;bottom:0;width:1.5px;transform:translateX(-50%)}
.g-tare::after{top:50%;left:0;right:0;height:1.5px;transform:translateY(-50%)}
.g-tare .box{position:absolute;inset:9px;border:1.5px solid var(--tare);border-radius:2px;background:var(--bg)}
.g-tare .box::after{content:"";position:absolute;inset:4px;border:1px dashed var(--tare);opacity:.5;border-radius:1px}
/* zen window glyph */
.g-zen{width:46px;height:40px;border:2px solid var(--zen);position:relative;background:var(--panel)}
.g-zen::before{content:"";position:absolute;top:0;left:0;right:0;height:9px;border-bottom:2px solid var(--zen);
  background:repeating-linear-gradient(180deg,transparent 0 1.5px,var(--zen) 1.5px 3px);opacity:.85}
.g-zen::after{content:"";position:absolute;left:9px;right:9px;top:16px;height:2px;background:var(--zen);
  box-shadow:0 6px 0 var(--zen),0 12px 0 var(--zen);opacity:.55}

.about{padding:74px 0 0;display:flex;gap:60px;align-items:baseline}
.about .lab{font-family:var(--font-mono);font-size:10px;letter-spacing:.3em;color:var(--faint);flex:none}
.about p{color:var(--dim);max-width:38em}
.about p a{color:var(--accent);border-bottom:1px solid transparent}
.about p a:hover{border-color:var(--accent)}

/* ================= PRODUCT PAGE ================= */
.crumb{font-family:var(--font-mono);font-size:10.5px;color:var(--faint);padding-top:34px;letter-spacing:.1em}
.crumb a:hover{color:var(--dim)}
.phero{display:flex;gap:44px;align-items:center;padding:44px 0 30px}
.phero .icon{
  width:132px;height:132px;border-radius:30px;flex:none;
  border:1px solid var(--line-strong);background:var(--panel-hi);
  display:flex;align-items:center;justify-content:center;box-shadow:var(--shadow);
}
.phero .icon .g-sudoku{grid-template-columns:repeat(5,13px);grid-template-rows:repeat(5,13px);gap:3px}
.phero .icon .g-tare{width:68px;height:68px}
.phero .icon .g-zen{width:70px;height:60px}
.phero h1{font-family:var(--font-display);font-size:46px;letter-spacing:-.01em;font-weight:400}
.phero .tag{color:var(--dim);font-size:17px;margin-top:8px;max-width:30em}
.phero .row{display:flex;gap:12px;margin-top:22px;align-items:center}
.storebadge{
  display:inline-flex;align-items:center;gap:10px;border:1px solid var(--line-strong);
  border-radius:10px;padding:10px 18px;background:var(--panel-hi);
}
.storebadge .ap{font-size:22px;line-height:1}
.storebadge .t{line-height:1.25}
.storebadge .t small{display:block;font-size:9.5px;color:var(--faint);letter-spacing:.06em}
.storebadge .t b{font-size:14.5px;font-weight:600}
.feat{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);border:1px solid var(--line);margin-top:44px}
.feat .f{background:var(--bg);padding:22px 20px}
.feat .f:hover{background:var(--panel)}
.feat .fk{font-family:var(--font-mono);font-size:9.5px;letter-spacing:.22em;margin-bottom:8px}
.feat .fv{color:var(--dim);font-size:13.5px;line-height:1.65}
.feat .fv b{color:var(--text);font-weight:600}
/* per-product accent on feature keys */
.accent-sudoku .feat .fk{color:var(--sudoku)}
.accent-tare .feat .fk{color:var(--tare)}
.accent-zen .feat .fk{color:var(--zen)}
.shots{display:flex;gap:18px;margin-top:44px}
.shot{
  flex:1;aspect-ratio:9/16;max-width:220px;border:1px solid var(--line-strong);border-radius:22px;
  background:
    linear-gradient(var(--line) 1px,transparent 1px) 0 0/100% 25%,
    var(--panel-hi);
  display:flex;align-items:center;justify-content:center;
  font-family:var(--font-mono);font-size:9px;letter-spacing:.2em;color:var(--faint);
  overflow:hidden;
}
.shot.wide{aspect-ratio:16/7;max-width:none;border-radius:16px}
.shot img{width:100%;height:100%;object-fit:cover;display:block}
.plinks{margin-top:44px;display:flex;gap:26px;font-family:var(--font-mono);font-size:11px;color:var(--dim)}
.plinks a{border-bottom:1px solid var(--line-strong);padding-bottom:2px}
.plinks a:hover{color:var(--accent)}

/* ================= LEGAL / SUPPORT ================= */
.legal{max-width:660px;padding-top:40px}
.legal h1{font-family:var(--font-display);font-size:32px;letter-spacing:-.005em;margin:18px 0 6px;font-weight:400}
.legal .upd{font-family:var(--font-mono);font-size:10.5px;color:var(--faint);letter-spacing:.1em;margin-bottom:34px}
.legal h2{font-size:16px;margin:32px 0 10px;letter-spacing:-.01em}
.legal p{color:var(--dim);margin-bottom:14px;font-size:14.5px}
.legal p b{color:var(--text);font-weight:600}
.legal ul{color:var(--dim);font-size:14.5px;margin:0 0 14px 18px}
.legal li{margin-bottom:6px}
.legal a{color:var(--accent)}
.legal .hl{
  border:1px solid var(--line-strong);border-left:3px solid var(--accent);
  background:var(--panel);padding:14px 18px;margin:22px 0;color:var(--dim);font-size:14px;
}
.accent-sudoku .legal .hl{border-left-color:var(--sudoku)}
.accent-tare .legal .hl{border-left-color:var(--tare)}
.accent-zen .legal .hl{border-left-color:var(--zen)}

/* ================= RESPONSIVE (deviation: draft is desktop-only;
   rules below only reflow, they change no tokens) ================= */
@media (max-width: 900px){
  .hero{flex-direction:column;align-items:flex-start;gap:64px;padding-bottom:64px}
  .orbit-wrap{align-self:center;transform:scale(.82);margin:-30px 0}
}
@media (max-width: 720px){
  .wrap{padding:0 20px}
  .hero h1{font-size:42px}
  .brand{letter-spacing:.22em;font-size:11px;gap:9px}
  .nav .links{gap:14px;font-size:12px}
  .pcard{flex-wrap:wrap;gap:18px}
  .pcard .orbidx{width:auto;order:-1;flex-basis:100%;line-height:1.4;display:flex;gap:14px}
  .pcard .cta{flex-direction:row;align-items:center;gap:14px;flex-basis:100%;justify-content:space-between}
  .phero{flex-direction:column;align-items:flex-start;gap:28px}
  .feat{grid-template-columns:1fr}
  .shots{flex-wrap:wrap}
  .shot{max-width:46%;flex-basis:46%}
  .about{flex-direction:column;gap:18px}
}