:root{
  --bg:#0d0f12;
  --surface:#14171c;
  --surface-2:#1a1e24;
  --text:#f7f7f5;
  --muted:#a6adb7;
  --line:#252a31;
  --accent:#f05a47;
  --max:1280px;
}

*{box-sizing:border-box}

html{scroll-behavior:smooth}

body{
  margin:0;
  min-height:100vh;
  font-family:"Yu Gothic","Hiragino Kaku Gothic ProN",system-ui,sans-serif;
  color:var(--text);
  background:var(--bg);
  line-height:1.75;
}

a{color:inherit}

.site-header{
  position:sticky;
  top:0;
  z-index:50;
  background:rgba(13,15,18,.88);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
}

.header-inner{
  width:min(var(--max),calc(100% - 64px));
  min-height:72px;
  margin:auto;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:40px;
}

.brand{
  font-size:22px;
  font-weight:1000;
  letter-spacing:.12em;
  text-decoration:none;
}

.brand span{color:var(--accent)}

.nav{
  display:flex;
  gap:28px;
  align-items:center;
  flex-wrap:wrap;
}

.nav a{
  color:var(--muted);
  text-decoration:none;
  font-size:14px;
  transition:color .2s ease;
}

.nav a:hover{color:var(--text)}

main{
  width:min(var(--max),calc(100% - 64px));
  margin:auto;
}

.hero{
  min-height:620px;
  display:grid;
  grid-template-columns:minmax(0,1.4fr) minmax(320px,.6fr);
  gap:80px;
  align-items:center;
  padding:96px 0;
}

.eyebrow{
  margin:0 0 18px;
  color:var(--accent);
  font-size:12px;
  font-weight:900;
  letter-spacing:.18em;
}

.hero h1{
  margin:0;
  max-width:780px;
  font-size:clamp(52px,7vw,104px);
  line-height:.98;
  letter-spacing:-.04em;
}

.hero p{
  max-width:760px;
  margin:30px 0 0;
  color:var(--muted);
  font-size:18px;
}

.hero-mark-wrap{
  display:flex;
  justify-content:flex-end;
}

.hero-mark{
  width:min(100%,360px);
  aspect-ratio:1;
  display:grid;
  place-items:center;
  border:1px solid var(--line);
  border-radius:32px;
  background:linear-gradient(145deg,#191d23,#101216);
  font-size:clamp(92px,12vw,160px);
  font-weight:1000;
  letter-spacing:-.08em;
  box-shadow:0 30px 80px rgba(0,0,0,.22);
}

.hero-mark span{color:var(--accent)}

.button-row{
  display:flex;
  flex-wrap:wrap;
  gap:14px;
  margin-top:34px;
}

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:48px;
  padding:0 22px;
  border:1px solid var(--line);
  border-radius:12px;
  background:var(--surface);
  text-decoration:none;
  font-weight:900;
  font-size:14px;
}

.btn.primary{
  color:white;
  background:var(--accent);
  border-color:var(--accent);
}

.section{
  padding:96px 0;
  border-top:1px solid var(--line);
}

.section-head{
  display:flex;
  justify-content:space-between;
  align-items:end;
  gap:40px;
  margin-bottom:36px;
}

.section h2{
  margin:0;
  font-size:clamp(34px,4vw,52px);
  line-height:1.15;
  letter-spacing:-.03em;
}

.section-lead{
  max-width:680px;
  margin:0;
  color:var(--muted);
}

.feature-game{
  display:grid;
  grid-template-columns:minmax(0,1.2fr) minmax(280px,.8fr);
  gap:48px;
  padding:40px;
  border:1px solid var(--line);
  border-radius:24px;
  background:var(--surface);
}

.feature-copy{
  display:flex;
  flex-direction:column;
  align-items:flex-start;
}

.game-badge{
  display:inline-block;
  margin-bottom:18px;
  padding:5px 10px;
  border-radius:999px;
  background:rgba(240,90,71,.12);
  color:#ff8d7f;
  font-size:11px;
  font-weight:900;
  letter-spacing:.1em;
}

.feature-game h3{
  margin:0 0 14px;
  font-size:36px;
}

.feature-game p{
  margin:0 0 28px;
  color:var(--muted);
}

.feature-visual{
  min-height:260px;
  display:grid;
  place-items:center;
  border:1px solid var(--line);
  border-radius:18px;
  background:var(--surface-2);
  font-size:72px;
  font-weight:1000;
  color:var(--accent);
}

.simple-grid{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:20px;
}

.card{
  padding:28px;
  border:1px solid var(--line);
  border-radius:18px;
  background:var(--surface);
}

.card h3{
  margin:0 0 10px;
  font-size:22px;
}

.card p{
  margin:0;
  color:var(--muted);
}

.page-title{
  padding:92px 0 46px;
}

.page-title h1{
  margin:0;
  font-size:clamp(44px,6vw,76px);
  line-height:1;
  letter-spacing:-.04em;
}

.page-title .section-lead{
  margin-top:22px;
}

.prose{
  max-width:900px;
  padding-bottom:96px;
}

.prose h2{
  margin:52px 0 12px;
  font-size:28px;
}

.prose p,
.prose li{
  color:#c2c8d0;
}

.notice,
.contact-box{
  margin:28px 0;
  padding:24px;
  border:1px solid var(--line);
  border-radius:16px;
  background:var(--surface);
}

.notice{
  border-color:#4e452a;
  background:#211e14;
  color:#efe0a2;
}

.site-footer{
  border-top:1px solid var(--line);
}

.footer-inner{
  width:min(var(--max),calc(100% - 64px));
  min-height:110px;
  margin:auto;
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:24px;
  flex-wrap:wrap;
  color:var(--muted);
  font-size:13px;
}

.footer-links{
  display:flex;
  gap:20px;
  flex-wrap:wrap;
}

.footer-links a{text-decoration:none}

@media(max-width:900px){
  .header-inner,
  main,
  .footer-inner{
    width:min(100% - 32px,var(--max));
  }

  .header-inner{
    min-height:auto;
    padding:16px 0;
    align-items:flex-start;
    flex-direction:column;
    gap:10px;
  }

  .nav{gap:14px 18px}

  .hero{
    min-height:auto;
    grid-template-columns:1fr;
    gap:42px;
    padding:64px 0 76px;
  }

  .hero-mark-wrap{justify-content:flex-start}

  .hero-mark{width:260px}

  .section{padding:72px 0}

  .section-head{
    align-items:flex-start;
    flex-direction:column;
    gap:16px;
  }

  .feature-game{
    grid-template-columns:1fr;
    gap:28px;
    padding:28px;
  }

  .simple-grid{grid-template-columns:1fr}

  .page-title{padding:68px 0 34px}
}

@media(max-width:560px){
  .hero h1{font-size:48px}
  .hero p{font-size:16px}
  .hero-mark{width:210px;border-radius:24px}
  .feature-game{padding:22px}
  .feature-game h3{font-size:30px}
}

.sishuku-logo {
  width: 80%;
  height: 80%;
  object-fit: contain;
  display: block;
}