.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: 0.7rem clamp(1rem, 3vw, 2rem);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--bg) 70%, transparent);
  border-bottom: 1px solid var(--border);
}
.brand { display: inline-flex; align-items: center; gap: 0.6rem; background: none; border: 0; padding: 0.2rem 0.4rem; font-weight: 800; font-size: 1.15rem; letter-spacing: -0.01em; border-radius: 10px; color: var(--text); text-decoration: none; }
.brand-text { transition: color 0.35s ease; }
.brand:hover .brand-text, .brand:focus-visible .brand-text { color: var(--accent); }
[data-theme='light'] .brand:hover .brand-text, [data-theme='light'] .brand:focus-visible .brand-text { color: #6a4cf0; }
.brand-mark { width: 30px; height: 30px; border-radius: 8px; overflow: hidden; display: inline-block; }
.brand-mark svg { width: 100%; height: 100%; }
.mark-slider { transition: transform 0.5s var(--ease-spring); }
.brand:hover .mark-slider, .brand:focus-visible .mark-slider { transform: translateX(26px); }
.topnav { display: flex; align-items: center; gap: 0.5rem; }

main { padding: 0 clamp(1rem, 3vw, 2rem) 3rem; max-width: 1380px; margin: 0 auto; }
.view[hidden] { display: none !important; }

/* Home */
.hero {
  display: grid; grid-template-columns: 1.1fr 1fr; gap: clamp(1.5rem, 4vw, 4rem); align-items: center;
  padding: clamp(2rem, 6vh, 5rem) 0 clamp(1.5rem, 4vh, 3rem);
}
.eyebrow { text-transform: uppercase; letter-spacing: 0.14em; font-size: 0.75rem; font-weight: 700; color: var(--accent-2); margin-bottom: 0.8rem; }
.hero h1 { font-size: clamp(2.4rem, 6vw, 4.6rem); line-height: 1.02; font-weight: 800; letter-spacing: -0.03em; }
.lead { margin-top: 1.1rem; font-size: clamp(1rem, 1.6vw, 1.2rem); color: var(--muted); max-width: 34rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.7rem; margin-top: 1.6rem; }
.hero-demo { display: flex; flex-direction: column; align-items: center; gap: 0.7rem; }
.hero-demo-stage { width: min(100%, 420px); aspect-ratio: 1; }
.hero-demo-caption { font-size: 0.85rem; color: var(--muted); text-align: center; }

.section-title { font-size: 1.2rem; font-weight: 700; margin: 1.2rem 0 0.9rem; }
.mode-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 0.9rem; }
.mode-card {
  position: relative; text-align: left; display: flex; flex-direction: column; gap: 0.35rem;
  padding: 1.15rem 1.15rem 1rem; border-radius: var(--radius); border: 1px solid var(--border);
  background: var(--surface); box-shadow: var(--shadow-sm);
  transition: transform 0.25s var(--ease-out), border-color 0.2s, background 0.2s, box-shadow 0.25s;
  overflow: hidden;
}
.mode-card::before { content: ''; position: absolute; inset: 0; background: radial-gradient(500px 200px at 0% 0%, rgba(139, 108, 255, 0.28), transparent 60%); opacity: 0; transition: opacity 0.3s; }
.mode-card:hover { transform: translateY(-4px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.mode-card:hover::before { opacity: 1; }
.mode-icon { width: 42px; height: 42px; border-radius: 12px; background: var(--accent-grad); color: #fff; display: grid; place-items: center; padding: 8px; margin-bottom: 0.4rem; position: relative; }
.mode-icon svg { width: 100%; height: 100%; fill: currentColor; }
.mode-name { font-weight: 700; font-size: 1.1rem; position: relative; }
.mode-tagline { color: var(--muted); font-size: 0.9rem; position: relative; }
.mode-meta { margin-top: 0.4rem; font-size: 0.75rem; font-weight: 600; color: var(--accent-2); position: relative; }
.foot { margin-top: 3rem; text-align: center; color: var(--muted); font-size: 0.82rem; }

/* Game */
.game-layout { display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 1.4rem; padding-top: 1rem; align-items: start; }
.board-column { display: flex; flex-direction: column; gap: 0.8rem; min-width: 0; }
.board-topline { display: flex; align-items: center; gap: 0.8rem; flex-wrap: wrap; }
.mode-chip { display: inline-flex; align-items: center; gap: 0.5rem; font-weight: 700; font-size: 1.05rem; }
.mode-chip-icon { width: 28px; height: 28px; border-radius: 8px; background: var(--accent-grad); color: #fff; padding: 5px; }
.mode-chip-icon svg { width: 100%; height: 100%; fill: currentColor; }
.live-stats { margin-left: auto; display: flex; gap: 1.2rem; }
.live-stat { display: flex; flex-direction: column; align-items: flex-end; line-height: 1.1; }
.live-label { font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--muted); font-weight: 700; }
.live-value { font-size: 1.5rem; font-weight: 800; font-variant-numeric: tabular-nums; letter-spacing: -0.02em; }
.board-stage { width: 100%; height: min(78vh, calc(100vw - 2rem)); max-height: 820px; display: flex; align-items: center; justify-content: center; }
.twist-controls { display: flex; justify-content: center; gap: 0.8rem; }
.btn-twist { padding: 0.7rem 1.2rem; font-size: 1rem; }
.board-under { display: flex; flex-direction: column; gap: 0.35rem; max-width: 640px; width: 100%; margin: 0 auto; font-size: 0.85rem; color: var(--muted); }

.side-panel { display: flex; flex-direction: column; gap: 0.9rem; position: sticky; top: 80px; }
.panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1rem 1.05rem; box-shadow: var(--shadow-sm); backdrop-filter: blur(10px); }
.panel-title { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.12em; font-weight: 700; color: var(--accent-2); margin-bottom: 0.6rem; }
.mode-desc { color: var(--muted); font-size: 0.9rem; margin-bottom: 0.8rem; }
.control-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.5rem; margin-bottom: 0.7rem; }
.control-row { display: flex; align-items: center; justify-content: space-between; gap: 0.6rem; margin-top: 0.55rem; }
.control-label { font-size: 0.8rem; font-weight: 700; color: var(--muted); text-transform: uppercase; letter-spacing: 0.08em; }
.skin-btn { max-width: 200px; }
.skin-btn img { width: 22px; height: 22px; border-radius: 5px; object-fit: cover; }
.skin-btn span { overflow: hidden; text-overflow: ellipsis; }
.preview-toggle { cursor: pointer; }
.preview-box { margin-top: 0.7rem; border-radius: 12px; overflow: hidden; border: 1px solid var(--border); background: rgba(0, 0, 0, 0.25); box-shadow: var(--shadow-sm); }
.preview-box img { width: 100%; aspect-ratio: 1; object-fit: cover; }
.preview-grid { display: grid; grid-template-columns: repeat(var(--n), 1fr); gap: 3px; padding: 3px; aspect-ratio: 1; }
.preview-grid span {
  display: grid; place-items: center; border-radius: 5px; font-weight: 800; color: #fff; font-size: 0.85rem;
  background: linear-gradient(150deg, hsl(var(--hue) 84% 68%), hsl(calc(var(--hue) + 28) 80% 47%));
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.35);
}
.preview-grid span.blank { background: transparent; }
.bests { display: grid; grid-template-columns: 1fr 1fr; gap: 0.5rem; margin-top: 0.9rem; }
.best { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 0.5rem 0.7rem; }
.best-label { font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--muted); font-weight: 700; }
.best-value { font-weight: 800; font-size: 1.1rem; font-variant-numeric: tabular-nums; }

@media (max-width: 1000px) {
  .game-layout { grid-template-columns: 1fr; }
  .side-panel { position: static; }
  .board-stage { height: min(70vh, calc(100vw - 2rem)); }
}
@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; text-align: center; padding-top: 1.5rem; }
  .lead { margin-inline: auto; }
  .hero-actions { justify-content: center; }
  .hero-demo-stage { width: min(100%, 320px); }
}
@media (max-width: 560px) {
  .brand span:last-child { display: none; }
  .topbar { padding-inline: 0.8rem; }
  .live-value { font-size: 1.2rem; }
  .board-stage { height: min(62vh, calc(100vw - 2rem)); }
  .control-grid { grid-template-columns: 1fr 1fr; }
  .btn-twist { padding: 0.6rem 0.8rem; font-size: 0.9rem; }
}