/* ==========================================================================
   スマホゲーム進化史  —  original theme
   ========================================================================== */
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
img{max-width:100%;display:block}
a{text-decoration:none;color:inherit}
ul,ol{list-style:none}
body{-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
@media (prefers-reduced-motion: reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
:focus-visible{outline:2px solid var(--neon);outline-offset:3px}

:root{
  --bg:#0d0b1a;
  --bg2:#14112b;
  --panel:#1b1738;
  --panel2:#221d47;
  --ink:#eae7ff;
  --muted:#9b93c9;
  --line:rgba(140,120,255,.18);
  --neon:#00e5c7;
  --neon2:#ff4d9d;
  --grape:#7b5cff;
  --amber:#ffcb47;
  --ff-disp:'Zen Kaku Gothic New',sans-serif;
  --ff-body:'Zen Kaku Gothic New',sans-serif;
  --ff-code:'DotGothic16',monospace;
  --maxw:1080px;
  --radius:18px;
}

body{
  font-family:var(--ff-body);
  background:
    radial-gradient(1200px 600px at 80% -10%,rgba(123,92,255,.22),transparent 60%),
    radial-gradient(900px 500px at 0% 10%,rgba(255,77,157,.14),transparent 55%),
    var(--bg);
  color:var(--ink);
  line-height:1.9;
  font-size:16px;
  min-height:100vh;
}

/* ---------- top bar ---------- */
.topbar{
  position:sticky;top:0;z-index:80;
  backdrop-filter:blur(14px);
  background:rgba(13,11,26,.72);
  border-bottom:1px solid var(--line);
}
.topbar .tb-in{
  max-width:var(--maxw);margin:0 auto;
  padding:16px 24px;
  display:flex;align-items:center;gap:26px;
}
.brand{display:flex;align-items:center;gap:11px;margin-right:auto}
.brand-mark{
  width:34px;height:34px;flex-shrink:0;
  border-radius:9px;
  background:linear-gradient(135deg,var(--neon),var(--grape));
  display:grid;place-items:center;
  box-shadow:0 0 18px -2px var(--neon);
}
.brand-mark span{font-family:var(--ff-code);font-size:17px;color:#0d0b1a;font-weight:700}
.brand-name{font-family:var(--ff-disp);font-weight:900;font-size:18px;letter-spacing:.02em}
.brand-name em{font-style:normal;color:var(--neon)}
.main-nav ul{display:flex;gap:6px}
.main-nav a{
  display:block;padding:9px 15px;border-radius:999px;
  font-size:14px;font-weight:700;color:var(--muted);
  transition:.22s;
}
.main-nav a:hover{color:var(--ink);background:var(--panel2)}
.main-nav li.is-active a{color:#0d0b1a;background:var(--neon);box-shadow:0 0 16px -2px var(--neon)}
.burger{display:none;width:44px;height:44px;background:none;border:1px solid var(--line);
  border-radius:10px;cursor:pointer;flex-direction:column;justify-content:center;align-items:center;gap:5px;padding:0}
.burger span{display:block;width:19px;height:2px;background:var(--ink);transition:.3s}
.burger[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.burger[aria-expanded="true"] span:nth-child(2){opacity:0}
.burger[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
.drawer{display:none}

/* ---------- home hero ---------- */
.hero{
  max-width:var(--maxw);margin:0 auto;
  padding:78px 24px 40px;
  position:relative;
}
.hero .tag{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--ff-code);font-size:12px;letter-spacing:.14em;
  color:var(--neon);
  border:1px solid var(--line);border-radius:999px;
  padding:7px 15px;margin-bottom:26px;
}
.hero .tag::before{content:"";width:8px;height:8px;border-radius:50%;background:var(--neon);box-shadow:0 0 10px var(--neon)}
.hero h1{
  font-family:var(--ff-disp);font-weight:900;
  font-size:clamp(32px,6.2vw,60px);line-height:1.28;
  letter-spacing:.01em;margin-bottom:22px;
}
.hero h1 .gr{
  background:linear-gradient(100deg,var(--neon),var(--neon2) 60%,var(--amber));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero .lead{color:var(--muted);font-size:17px;max-width:60ch}
.hero-scene{margin-top:44px;border-radius:var(--radius);overflow:hidden;border:1px solid var(--line);box-shadow:0 40px 80px -50px rgba(0,0,0,.9)}
.hero-scene svg{width:100%;display:block}

/* ---------- timeline / journey ---------- */
.journey{max-width:var(--maxw);margin:0 auto;padding:64px 24px}
.sec-h{margin-bottom:34px}
.sec-h .kw{font-family:var(--ff-code);font-size:12px;letter-spacing:.2em;color:var(--neon2);text-transform:uppercase}
.sec-h h2{font-family:var(--ff-disp);font-weight:900;font-size:clamp(24px,4vw,34px);margin-top:8px}
.rail{position:relative;padding-left:34px}
.rail::before{content:"";position:absolute;left:9px;top:6px;bottom:6px;width:2px;
  background:linear-gradient(var(--neon),var(--grape),var(--neon2))}
.stop{position:relative;margin-bottom:20px}
.stop::before{content:"";position:absolute;left:-31px;top:26px;width:14px;height:14px;border-radius:50%;
  background:var(--bg);border:3px solid var(--neon);box-shadow:0 0 12px -1px var(--neon)}
.stop:nth-child(2)::before{border-color:var(--grape);box-shadow:0 0 12px -1px var(--grape)}
.stop:nth-child(3)::before{border-color:var(--neon2);box-shadow:0 0 12px -1px var(--neon2)}
.stop:nth-child(4)::before{border-color:var(--amber);box-shadow:0 0 12px -1px var(--amber)}
.stop:nth-child(5)::before{border-color:var(--neon);box-shadow:0 0 12px -1px var(--neon)}
.stop a{
  display:grid;grid-template-columns:auto 1fr auto;gap:18px;align-items:center;
  background:linear-gradient(180deg,var(--panel),var(--panel2));
  border:1px solid var(--line);border-radius:var(--radius);
  padding:22px 24px;transition:.25s;
}
.stop a:hover{transform:translateX(6px);border-color:var(--neon)}
.stop .era{font-family:var(--ff-code);font-size:13px;color:var(--muted);min-width:56px}
.stop .body h3{font-family:var(--ff-disp);font-weight:900;font-size:18px;margin-bottom:4px}
.stop .body p{font-size:14px;color:var(--muted);line-height:1.7}
.stop .go{font-size:20px;color:var(--neon)}
@media(max-width:640px){.stop a{grid-template-columns:1fr;gap:8px}.stop .go{display:none}}

/* ---------- subpage ---------- */
.page-main{max-width:860px;margin:0 auto;padding:64px 24px 80px}
.page-head{margin-bottom:46px;padding-bottom:28px;border-bottom:1px solid var(--line);position:relative}
.page-head .eyebrow{display:inline-flex;align-items:center;gap:9px;font-family:var(--ff-code);font-size:12px;
  letter-spacing:.18em;color:var(--neon);margin-bottom:16px}
.page-head .eyebrow .no{color:var(--neon2);font-weight:700}
.page-head h1{font-family:var(--ff-disp);font-weight:900;font-size:clamp(28px,5.2vw,44px);line-height:1.3;margin-bottom:16px}
.page-head .lead{color:var(--muted);font-size:17px;max-width:62ch}

.block{margin:0 0 46px}
.block h2{font-family:var(--ff-disp);font-weight:900;font-size:clamp(20px,3.4vw,27px);
  margin-bottom:18px;padding-left:16px;position:relative}
.block h2::before{content:"";position:absolute;left:0;top:.2em;bottom:.2em;width:5px;border-radius:4px;
  background:linear-gradient(var(--neon),var(--grape))}
.block p{margin-bottom:15px;color:#d9d4f5}
.block p:last-child{margin-bottom:0}

.scene{margin:30px 0 8px;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;
  background:var(--bg2);box-shadow:0 24px 60px -44px #000}
.scene svg{width:100%;display:block}

.pager{display:flex;justify-content:space-between;gap:14px;margin-top:56px;padding-top:30px;border-top:1px solid var(--line)}
.pager a{flex:1;background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:16px 20px;transition:.25s}
.pager a:hover{border-color:var(--neon);background:var(--panel2)}
.pager small{font-family:var(--ff-code);font-size:11px;color:var(--muted);display:block;margin-bottom:5px}
.pager span{font-family:var(--ff-disp);font-weight:700;font-size:15px}
.pager .nx{text-align:right}
.pager .ph{visibility:hidden}
@media(max-width:520px){.pager{flex-direction:column}}

/* ---------- sitemap (list, not cards) ---------- */
.sitemap-list{border-top:1px solid var(--line)}
.sitemap-list li{border-bottom:1px solid var(--line)}
.sitemap-list a{display:grid;grid-template-columns:auto 1fr;gap:22px;align-items:start;padding:24px 8px;transition:.2s}
.sitemap-list a:hover{background:var(--panel);padding-left:18px}
.sitemap-list .num{font-family:var(--ff-code);font-size:14px;color:var(--neon2);padding-top:4px}
.sitemap-list .txt{display:block}
.sitemap-list .ttl{display:block;font-family:var(--ff-disp);font-weight:900;font-size:18px;margin-bottom:5px}
.sitemap-list .dsc{display:block;font-size:14px;color:var(--muted);line-height:1.75}
@media(max-width:520px){.sitemap-list a{grid-template-columns:auto 1fr;gap:14px}}

/* ---------- footer ---------- */
.site-footer{margin-top:80px;border-top:1px solid var(--line);
  background:linear-gradient(180deg,transparent,rgba(123,92,255,.06))}
.ft-in{max-width:var(--maxw);margin:0 auto;padding:52px 24px 28px;
  display:grid;grid-template-columns:1.4fr 1fr;gap:34px}
.ft-brand .ft-name{font-family:var(--ff-disp);font-weight:900;font-size:20px;margin-bottom:8px}
.ft-brand .ft-name em{font-style:normal;color:var(--neon)}
.ft-brand .ft-tag{color:var(--muted);font-size:14px;margin-bottom:14px}
.ft-brand .ft-addr{color:var(--muted);opacity:.75;font-size:13px}
.ft-nav ul{display:grid;grid-template-columns:1fr 1fr;gap:11px 20px;font-size:14px}
.ft-nav a{color:var(--muted);transition:.2s}
.ft-nav a:hover{color:var(--neon)}
.ft-copy{max-width:var(--maxw);margin:0 auto;padding:18px 24px;border-top:1px solid var(--line);
  font-family:var(--ff-code);font-size:12px;color:var(--muted);text-align:center}
@media(max-width:640px){.ft-in{grid-template-columns:1fr;gap:24px}}

/* ---------- to top ---------- */
.to-top{position:fixed;right:20px;bottom:20px;width:48px;height:48px;border-radius:14px;
  background:var(--neon);color:#0d0b1a;display:flex;align-items:center;justify-content:center;
  font-size:20px;font-weight:900;opacity:0;pointer-events:none;transform:translateY(12px);
  transition:.3s;z-index:60;box-shadow:0 0 22px -4px var(--neon)}
.to-top.show{opacity:1;pointer-events:auto;transform:none}

/* ---------- reveal ---------- */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}

/* ---------- responsive nav ---------- */
@media(max-width:820px){
  .main-nav{display:none}
  .burger{display:flex}
  .drawer.open{display:block;position:absolute;top:100%;left:0;right:0;
    background:var(--bg2);border-bottom:1px solid var(--line)}
  .drawer.open ul{flex-direction:column;padding:10px 24px 18px}
  .drawer.open li{border-top:1px solid var(--line)}
  .drawer.open a{display:block;padding:14px 4px;font-weight:700;color:var(--ink)}
  .drawer.open li.is-active a{color:var(--neon)}
}