* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #07140a;
  --panel: #0d2113;
  --line: #1d4226;
  --text: #eafaee;
  --sub: #9fc7aa;
  --gold: #ffd75e;
  --red: #ff5d6c;
}

html, body {
  background: radial-gradient(120% 90% at 50% 0%, #0d2b15 0%, var(--bg) 60%);
  color: var(--text);
  font-family: "Hiragino Sans", "Noto Sans JP", "Yu Gothic UI", system-ui, sans-serif;
  min-height: 100%;
}

body { padding: 12px 10px 28px; -webkit-tap-highlight-color: transparent; }

.shell { max-width: 1060px; margin: 0 auto; display: grid; gap: 12px; }

.hero {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  background: linear-gradient(135deg, rgba(20,60,30,.65), rgba(10,26,15,.85));
  border: 1px solid var(--line); border-radius: 16px; padding: 14px 16px;
}
.eyebrow { color: var(--gold); font-size: 11px; letter-spacing: .12em; font-weight: 700; }
.hero h1 { font-size: clamp(20px, 4.2vw, 30px); letter-spacing: .04em; margin: 2px 0; }
.subtitle { color: var(--sub); font-size: clamp(11px, 2.6vw, 13px); line-height: 1.5; }
.hub-link {
  flex: none; color: #07140a; background: var(--gold); text-decoration: none;
  font-weight: 800; padding: 9px 16px; border-radius: 999px; font-size: 13px;
  box-shadow: 0 4px 14px rgba(255, 215, 94, .25);
}

.stage-wrap {
  position: relative; border-radius: 16px; overflow: hidden;
  border: 1px solid var(--line); background: #050d07;
  box-shadow: 0 18px 50px rgba(0,0,0,.45);
}
#game { display: block; width: 100%; touch-action: none; }

.howto { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.howto-card {
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 12px 14px;
}
.howto-card .label {
  display: inline-block; font-size: 10px; font-weight: 800; letter-spacing: .14em;
  color: #07140a; background: var(--gold); border-radius: 999px; padding: 3px 10px; margin-bottom: 7px;
}
.howto-card:last-child .label { background: var(--red); color: #fff; }
.howto-card p { color: var(--sub); font-size: 12px; line-height: 1.7; }
.howto-card b { color: var(--text); }

.support-strip { display: flex; flex-wrap: wrap; gap: 10px; }
.support-strip a {
  flex: 1 1 200px; text-align: center; text-decoration: none; font-weight: 700; font-size: 13px;
  color: var(--text); background: var(--panel); border: 1px solid var(--line);
  border-radius: 12px; padding: 12px 10px;
}
.support-strip a:first-child { border-color: rgba(255, 215, 94, .45); color: var(--gold); }

@media (max-width: 640px) {
  .howto { grid-template-columns: 1fr; }
  body { padding: 8px 6px 22px; }
}