* { box-sizing: border-box; }
body {
  margin: 0;
  background: #fff;
  color: #222;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
}

header { text-align: center; padding: 60px 20px 10px; }
h1 { margin: 0; font-size: 44px; font-weight: 800; letter-spacing: -1px; }
header p { margin: 8px 0 0; color: #888; font-size: 18px; }

/* mute */
#mute {
  position: fixed; top: 16px; right: 16px;
  width: 44px; height: 44px; border-radius: 50%;
  border: 0; background: #f2f2f2; color: #222; cursor: pointer;
  display: grid; place-items: center;
}
#mute:hover { background: #e6e6e6; }
#mute.on { background: #222; color: #fff; }

/* filters */
#filters { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; padding: 24px 20px 0; }
#filters button {
  font: inherit; font-size: 15px; padding: 6px 14px; border-radius: 999px;
  border: 0; background: none; color: #888; cursor: pointer;
}
#filters button:hover { color: #222; }
#filters button.on { background: #222; color: #fff; }

/* grid */
#grid {
  max-width: 1000px; margin: 30px auto 80px; padding: 0 20px;
  display: grid; gap: 28px;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}
.card { text-decoration: none; color: inherit; }
.thumb {
  aspect-ratio: 1; border-radius: 16px; overflow: hidden;
  display: grid; place-items: center; font-size: 72px;
  transition: transform .15s;
}
.thumb img { width: 100%; height: 100%; object-fit: cover; }
.card:hover .thumb { transform: scale(1.04); }
.card h2 { font-size: 17px; font-weight: 600; margin: 10px 2px 0; }

#empty { grid-column: 1 / -1; text-align: center; color: #888; }

@media (max-width: 500px) {
  h1 { font-size: 34px; }
  #grid { grid-template-columns: 1fr 1fr; gap: 16px; }
  .thumb { font-size: 52px; }
}