:root{
  --bg:#f6f8fb; --card:#ffffff; --ink:#1c2733; --muted:#5b6b7b; --line:#dde5ee;
  --brand:#2563eb; --brand-dark:#1e40af; --accent:#f59e0b; --ok:#15803d; --bad:#b91c1c;
  --radius:14px; --shadow:0 6px 24px rgba(20,40,80,.08);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.65;font-size:17px}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:1080px;margin:0 auto;padding:0 18px}
header.site{background:#0f2a5c;color:#fff;position:sticky;top:0;z-index:50;box-shadow:0 2px 10px rgba(0,0,0,.18)}
header.site .wrap{display:flex;align-items:center;gap:18px;padding-top:10px;padding-bottom:10px;flex-wrap:wrap}
.logo{display:flex;align-items:center;gap:10px;color:#fff;font-weight:800;font-size:1.25rem;letter-spacing:.2px}
.logo:hover{text-decoration:none}
.logo .mark{display:inline-flex;width:36px;height:36px;border-radius:9px;background:var(--accent);color:#122;align-items:center;justify-content:center}
nav.main{display:flex;gap:4px;margin-left:auto;flex-wrap:wrap}
nav.main a{color:#dbe7ff;padding:8px 12px;border-radius:8px;font-size:.98rem}
nav.main a:hover{background:rgba(255,255,255,.12);text-decoration:none;color:#fff}
.hero{background:linear-gradient(135deg,#0f2a5c,#2563eb);color:#fff;padding:52px 0 44px}
.hero h1{font-size:2.3rem;line-height:1.2;margin:0 0 14px}
.hero p{max-width:720px;color:#dbe7ff;font-size:1.08rem;margin:0 0 20px}
.btn{display:inline-block;background:var(--accent);color:#231a00;font-weight:700;padding:11px 20px;border-radius:10px}
.btn:hover{text-decoration:none;background:#fbbf24}
.btn.secondary{background:#fff;color:var(--brand-dark)}
main{padding:34px 0 10px}
h1{font-size:2rem;line-height:1.25;margin:0 0 14px}
h2{font-size:1.45rem;margin:34px 0 12px;line-height:1.3}
h3{font-size:1.15rem;margin:22px 0 8px}
p{margin:0 0 14px}
ul,ol{margin:0 0 16px;padding-left:22px}
li{margin-bottom:6px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px;margin:18px 0 8px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow)}
.card h3{margin-top:0}
.card p{color:var(--muted);font-size:.97rem}
.card .go{font-weight:700}
.icon{width:44px;height:44px;border-radius:11px;background:#e8effe;display:inline-flex;align-items:center;justify-content:center;margin-bottom:10px}
.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow);margin:20px 0}
label{font-weight:600;display:block;margin:12px 0 6px}
input[type=text],input[type=number],input[type=date],input[type=email],select,textarea{width:100%;padding:11px 12px;border:1px solid var(--line);border-radius:9px;font-size:1rem;font-family:inherit;background:#fff;color:var(--ink)}
textarea{resize:vertical}
button.go-btn,.calc-btn{background:var(--brand);color:#fff;border:0;padding:11px 20px;border-radius:9px;font-size:1rem;font-weight:700;cursor:pointer}
button.go-btn:hover,.calc-btn:hover{background:var(--brand-dark)}
button.ghost{background:#eef2f7;color:var(--ink);border:1px solid var(--line);padding:10px 16px;border-radius:9px;cursor:pointer;font-weight:600}
.row{display:flex;gap:14px;flex-wrap:wrap}
.row>div{flex:1;min-width:180px}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:12px;margin:16px 0}
.stat{background:#eef4ff;border:1px solid #cfdefe;border-radius:11px;padding:14px;text-align:center}
.stat b{display:block;font-size:1.5rem;color:var(--brand-dark)}
.stat span{color:var(--muted);font-size:.9rem}
.result{background:#f0fdf4;border:1px solid #bbe9c6;border-radius:11px;padding:16px;margin-top:16px}
.note{background:#fffbeb;border:1px solid #fde68a;border-radius:11px;padding:14px 16px;margin:16px 0;font-size:.97rem}
.faq{border-top:1px solid var(--line);margin-top:10px}
.faq details{border-bottom:1px solid var(--line);padding:12px 2px}
.faq summary{font-weight:700;cursor:pointer}
input[type=range]{width:100%}
.meter{height:12px;background:#e5eaf1;border-radius:8px;overflow:hidden;margin-top:8px}
.meter>i{display:block;height:100%;width:0;background:var(--bad);transition:width .25s}
.checks label{font-weight:400;display:flex;gap:8px;align-items:center;margin:6px 0}
.checks input{width:auto}
/* games */
.ttt-board{display:grid;grid-template-columns:repeat(3,96px);gap:8px;justify-content:center;margin:18px 0}
.ttt-board button{height:96px;font-size:2.4rem;font-weight:800;background:#eef4ff;border:2px solid #cfdefe;border-radius:12px;cursor:pointer;color:var(--brand-dark)}
.ttt-board button:disabled{cursor:default;opacity:.85}
.scorebar{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin:10px 0}
.scorebar .stat{min-width:110px}
.mem-grid{display:grid;grid-template-columns:repeat(4,84px);gap:10px;justify-content:center;margin:18px 0}
.mem-card{height:84px;border-radius:12px;border:2px solid #cfdefe;background:var(--brand);color:#fff;font-size:2rem;display:flex;align-items:center;justify-content:center;cursor:pointer;user-select:none}
.mem-card.hidden-card{background:var(--brand);color:transparent}
.mem-card.matched{background:var(--ok);border-color:var(--ok);cursor:default}
canvas#snakeCanvas{background:#0b1f3a;border-radius:12px;display:block;margin:14px auto;max-width:100%}
.dpad{display:grid;grid-template-columns:repeat(3,58px);gap:6px;justify-content:center;margin:10px auto}
.dpad button{height:48px;border-radius:10px;border:1px solid var(--line);background:#eef2f7;font-size:1.2rem;cursor:pointer}
.center{text-align:center}
footer.site{background:#0c1c38;color:#b9c8de;margin-top:48px;padding:38px 0 26px;font-size:.95rem}
footer.site a{color:#dbe7ff}
footer.site .cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:24px}
footer.site h4{color:#fff;margin:0 0 10px;font-size:1rem}
footer.site ul{list-style:none;padding:0;margin:0}
footer.site li{margin-bottom:7px}
footer.site .fine{border-top:1px solid rgba(255,255,255,.14);margin-top:26px;padding-top:16px;color:#8ea3c2;font-size:.88rem}
article.post{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow)}
.meta{color:var(--muted);font-size:.92rem;margin-bottom:16px}
.related{background:#eef4ff;border:1px solid #cfdefe;border-radius:11px;padding:16px 18px;margin-top:26px}
.form-note{font-size:.9rem;color:var(--muted)}
@media (max-width:640px){
  .hero h1{font-size:1.7rem}
  h1{font-size:1.6rem}
  .ttt-board{grid-template-columns:repeat(3,84px)}
  .ttt-board button{height:84px}
  .mem-grid{grid-template-columns:repeat(4,70px)}
  .mem-card{height:70px;font-size:1.6rem}
  article.post{padding:20px}
}