/* =============================================================================
   portal.css — ポータルサイト共通スタイル（トップ・ゲーム詳細・contact で使用）
   既存記事ページ（about.html 等）のサイバーテーマと同一のデザイントークンを使う。
   ========================================================================== */
:root {
  --neon-cyan: #00f3ff;
  --neon-magenta: #ff00ff;
  --bg-color: #0a0a0f;
  --panel: rgba(0, 0, 0, 0.7);
  --line: rgba(0, 243, 255, 0.2);
  --text: #ddd;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background-color: var(--bg-color);
  color: #fff;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  line-height: 1.8;
  background-image:
    linear-gradient(rgba(0, 243, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 243, 255, 0.03) 1px, transparent 1px);
  background-size: 30px 30px;
}

a { color: var(--neon-cyan); }

.container { max-width: 1080px; margin: 0 auto; padding: 0 1.25rem; }

/* --- welcome-back bar ------------------------------------------------------ */
.welcome-back {
  display: flex;
  gap: 1rem;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  padding: 0.6rem 1rem;
  background: linear-gradient(90deg, rgba(0, 243, 255, 0.15), rgba(255, 0, 255, 0.15));
  border-bottom: 1px solid var(--line);
  font-size: 0.95rem;
}

/* --- header ---------------------------------------------------------------- */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--line);
}
.brand {
  color: #fff;
  text-decoration: none;
  font-weight: 900;
  letter-spacing: 2px;
  font-size: 1.1rem;
  text-shadow: 0 0 10px rgba(0, 243, 255, 0.5);
}
.brand span { color: var(--neon-cyan); }
.site-nav { display: flex; gap: 1.2rem; flex-wrap: wrap; }
.site-nav a { color: #fff; text-decoration: none; font-size: 0.95rem; opacity: 0.85; }
.site-nav a:hover { color: var(--neon-cyan); opacity: 1; }

/* --- hero ------------------------------------------------------------------ */
.hero {
  text-align: center;
  padding: 4.5rem 1.25rem 3.5rem;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(ellipse at 30% 20%, rgba(0, 243, 255, 0.12), transparent 55%),
    radial-gradient(ellipse at 70% 80%, rgba(255, 0, 255, 0.10), transparent 55%);
}
.hero-eyebrow { color: var(--neon-cyan); letter-spacing: 2px; font-size: 0.85rem; margin: 0 0 0.75rem; }
.hero-title {
  margin: 0;
  font-size: clamp(2.5rem, 8vw, 4.5rem);
  letter-spacing: 4px;
  text-transform: uppercase;
  text-shadow: 0 0 18px rgba(0, 243, 255, 0.6), 0 0 45px rgba(255, 0, 255, 0.3);
}
.hero-sub { color: var(--text); font-size: 1.05rem; margin: 1.25rem 0 2rem; }
.hero-links { margin-top: 1.25rem; font-size: 0.9rem; }

/* --- buttons ---------------------------------------------------------------- */
.btn {
  display: inline-block;
  color: #001114;
  background: var(--neon-cyan);
  border: 1px solid var(--neon-cyan);
  text-decoration: none;
  font-weight: 700;
  padding: 10px 22px;
  border-radius: 4px;
  transition: all 0.25s;
}
.btn:hover { box-shadow: 0 0 18px rgba(0, 243, 255, 0.7); }
.btn-hero {
  font-size: 1.3rem;
  padding: 16px 44px;
  box-shadow: 0 0 25px rgba(0, 243, 255, 0.45);
}
.btn-ghost { color: #fff; background: rgba(0, 243, 255, 0.08); }
.btn-small { padding: 4px 14px; font-size: 0.85rem; }

/* --- sections ---------------------------------------------------------------- */
.section { padding: 3rem 0 0.5rem; }
.section-title {
  color: var(--neon-cyan);
  font-size: 1.7rem;
  letter-spacing: 3px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.5rem;
  text-shadow: 0 0 10px rgba(0, 243, 255, 0.4);
}
.section-title-ja { color: #fff; font-size: 1rem; letter-spacing: 1px; margin-left: 0.75rem; }

.prose { background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 1.5rem 2rem; }
.prose p { color: var(--text); }

/* --- game cards: auto-fill grid scales to dozens of titles ------------------ */
.game-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}
.game-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: border-color 0.25s, box-shadow 0.25s;
}
.game-card:hover { border-color: var(--neon-cyan); box-shadow: 0 0 20px rgba(0, 243, 255, 0.25); }
.card-thumb {
  position: relative;
  display: grid;
  place-items: center;
  height: 150px;
  text-decoration: none;
  overflow: hidden;
}
.thumb-label {
  position: absolute;
  bottom: 10px;
  color: #fff;
  font-size: 0.8rem;
  letter-spacing: 2px;
  background: rgba(0, 0, 0, 0.55);
  padding: 2px 12px;
  border-radius: 3px;
}
.thumb-emoji { font-size: 3.2rem; filter: drop-shadow(0 0 12px rgba(0, 243, 255, 0.6)); }
.thumb-gomoku {
  background:
    linear-gradient(rgba(0, 243, 255, 0.12) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 243, 255, 0.12) 1px, transparent 1px),
    radial-gradient(ellipse at 50% 120%, rgba(255, 0, 255, 0.25), #050508 70%);
  background-size: 24px 24px, 24px 24px, cover;
}
.thumb-stone { position: absolute; width: 34px; height: 34px; border-radius: 50%; }
.stone-cyan { left: 34%; top: 38%; background: radial-gradient(circle at 35% 30%, #bffcff, var(--neon-cyan) 60%); box-shadow: 0 0 16px var(--neon-cyan); }
.stone-magenta { left: 54%; top: 52%; background: radial-gradient(circle at 35% 30%, #ffc4ff, var(--neon-magenta) 60%); box-shadow: 0 0 16px var(--neon-magenta); opacity: 0.55; }
.thumb-reference { background: radial-gradient(ellipse at 50% 0%, rgba(0, 243, 255, 0.25), #071018 75%); }
.thumb-daifugo { background: radial-gradient(ellipse at 50% 0%, rgba(255, 0, 255, 0.25), #14060f 75%); }
.thumb-soon { background: repeating-linear-gradient(45deg, #0c0c14, #0c0c14 12px, #0f0f18 12px, #0f0f18 24px); }

.card-body { padding: 1.1rem 1.4rem 1.4rem; display: flex; flex-direction: column; flex: 1; }
.card-body h3 { margin: 0 0 0.4rem; font-size: 1.25rem; }
.card-body h3 a { color: #fff; text-decoration: none; }
.card-body h3 a:hover { color: var(--neon-cyan); }
.card-en { display: block; color: var(--neon-cyan); font-size: 0.75rem; letter-spacing: 2px; text-transform: uppercase; }
.card-tags { margin: 0 0 0.6rem; }
.card-tags span {
  display: inline-block;
  font-size: 0.72rem;
  color: var(--neon-cyan);
  border: 1px solid var(--line);
  border-radius: 3px;
  padding: 1px 8px;
  margin-right: 6px;
}
.card-body p { color: var(--text); font-size: 0.92rem; margin: 0 0 1rem; }
.card-actions { margin-top: auto; display: flex; gap: 0.6rem; }
.game-card-soon { opacity: 0.75; }

/* --- guide cards ------------------------------------------------------------- */
.guide-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.2rem;
  margin-top: 1.5rem;
}
.guide-card {
  display: block;
  text-decoration: none;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 1.1rem 1.4rem;
  transition: border-color 0.25s, box-shadow 0.25s;
}
.guide-card:hover { border-color: var(--neon-cyan); box-shadow: 0 0 16px rgba(0, 243, 255, 0.2); }
.guide-card h3 { margin: 0 0 0.4rem; font-size: 1.05rem; color: #fff; }
.guide-card p { margin: 0; color: var(--text); font-size: 0.88rem; }

/* --- FAQ / news --------------------------------------------------------------- */
.faq details {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0.8rem 1.3rem;
  margin-top: 0.8rem;
}
.faq summary { cursor: pointer; font-weight: 700; }
.faq p { color: var(--text); }
.news-list { list-style: none; padding: 0; margin-top: 1.2rem; }
.news-list li { border-bottom: 1px dashed var(--line); padding: 0.7rem 0; color: var(--text); }
.news-list time { color: var(--neon-cyan); margin-right: 1rem; font-size: 0.85rem; }
.news-more { text-align: right; }

/* --- footer -------------------------------------------------------------------- */
.site-footer { border-top: 1px solid var(--line); margin-top: 3.5rem; padding: 2.5rem 1.5rem 1.5rem; }
.footer-cols { display: flex; gap: 3.5rem; flex-wrap: wrap; max-width: 1080px; margin: 0 auto; }
.footer-cols h4 { color: var(--neon-cyan); letter-spacing: 2px; margin: 0 0 0.6rem; font-size: 0.85rem; }
.footer-cols a { display: block; color: var(--text); text-decoration: none; font-size: 0.9rem; padding: 2px 0; }
.footer-cols a:hover { color: var(--neon-cyan); }
.footer-copy { text-align: center; color: #888; font-size: 0.8rem; margin-top: 2rem; }

/* --- game detail page (games/*.html) ------------------------------------------- */
.detail-header { text-align: center; padding: 3rem 1.25rem 1rem; }
.detail-title {
  color: var(--neon-cyan);
  font-size: 2.2rem;
  letter-spacing: 2px;
  text-shadow: 0 0 10px rgba(0, 243, 255, 0.5);
  margin: 0 0 1rem;
}
.content-box {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 2.5rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
  margin-bottom: 2rem;
}
.content-box h2 {
  color: var(--neon-cyan);
  font-size: 1.6rem;
  margin-top: 2rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding-bottom: 0.5rem;
}
.content-box h2:first-child { margin-top: 0; }
.content-box p, .content-box ul { color: var(--text); }
.play-cta { text-align: center; margin: 2.5rem 0 0.5rem; }

@media (max-width: 640px) {
  .hero { padding: 3rem 1rem 2.5rem; }
  .content-box { padding: 1.5rem; }
  .footer-cols { gap: 2rem; }
}