:root {
  --bg-primary: #0a0a0c;
  --bg-surface: #121217;
  --bg-card: #1c1c24;
  --text-main: #f0f6fc;
  --text-muted: #8b949e;
  --border-subtle: #2d3848;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
.site-header { background: var(--bg-surface); border-bottom: 1px solid var(--border-subtle); padding: 0.75rem 1.25rem; }
.header-inner { max-width: 1000px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; }
.back-link { color: var(--text-muted); text-decoration: none; font-size: 0.95rem; }
.back-link:hover { color: #58a6ff; }
.logo-area { display: flex; align-items: center; gap: 0.5rem; font-weight: 600; }
.icon-button { background: var(--bg-card); border: 1px solid var(--border-subtle); color: #fff; padding: 0.5rem 0.75rem; border-radius: 8px; cursor: pointer; min-width: 44px; min-height: 44px; }
.game-container { max-width: 800px; margin: 1.5rem auto; padding: 0 1rem; flex: 1; display: flex; flex-direction: column; align-items: center; }
.game-header-text { text-align: center; margin-bottom: 1rem; }
.game-title { font-size: 1.75rem; font-weight: 800; margin-bottom: 0.35rem; color: #fff; }
.game-subtitle { color: var(--text-muted); font-size: 0.95rem; }
.settings-toolbar { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 1rem; justify-content: center; }
.mode-btn, .action-btn, .diff-select {
  background: var(--bg-card); color: var(--text-main); border: 1px solid var(--border-subtle); padding: 0.5rem 0.85rem; border-radius: 8px; cursor: pointer; min-height: 44px;
}
.mode-btn.active { background: #238636; border-color: #2ea043; color: #fff; font-weight: 600; }
.canvas-wrapper {
  position: relative; width: 600px; max-width: 100%; aspect-ratio: 600/400; box-shadow: 0 12px 36px rgba(0,0,0,0.8); border-radius: 12px; overflow: hidden; border: 4px solid #333; margin-bottom: 1.5rem; background: #000;
}
#game-canvas { display: block; width: 100%; height: 100%; touch-action: none; }
.overlay-screen { position: absolute; inset: 0; background: rgba(0,0,0,0.8); display: flex; align-items: center; justify-content: center; backdrop-filter: blur(4px); }
.overlay-screen.hidden { display: none; }
.overlay-content { text-align: center; color: #fff; padding: 1.5rem; }
.medal-icon { font-size: 3.5rem; display: block; margin-bottom: 0.5rem; }
.btn-primary { background: #238636; color: #fff; border: none; padding: 0.75rem 1.75rem; font-weight: 700; border-radius: 8px; cursor: pointer; margin-top: 1rem; font-size: 1rem; min-height: 44px; }
.content-block { max-width: 800px; width: 100%; background: var(--bg-surface); border: 1px solid var(--border-subtle); border-radius: 12px; padding: 1.75rem; line-height: 1.7; }
.article-header { border-bottom: 1px solid var(--border-subtle); padding-bottom: 1rem; margin-bottom: 1rem; }
.article-header h2 { font-size: 1.35rem; color: #fff; }
.article-meta { color: var(--text-muted); font-size: 0.85rem; }
.article-section { margin-bottom: 1.25rem; }
.article-section h3 { font-size: 1.1rem; color: #58a6ff; margin-bottom: 0.5rem; }
.article-section p { color: #c9d1d9; margin-bottom: 0.65rem; }
.article-section ul { padding-left: 1.5rem; color: #c9d1d9; margin-bottom: 0.65rem; }
.faq-accordion { display: flex; flex-direction: column; gap: 0.65rem; }
.faq-item { background: var(--bg-card); border: 1px solid var(--border-subtle); border-radius: 8px; padding: 0.75rem 1rem; }
.faq-question { font-weight: 600; cursor: pointer; color: #fff; }
.faq-answer { margin-top: 0.5rem; color: #8b949e; }
.site-footer { background: var(--bg-surface); border-top: 1px solid var(--border-subtle); padding: 1.5rem; text-align: center; color: var(--text-muted); font-size: 0.85rem; margin-top: auto; }