:root {
  --bg: #0b1220;
  --surface: rgba(255, 255, 255, 0.06);
  --surface2: rgba(255, 255, 255, 0.10);
  --text: rgba(255, 255, 255, 0.92);
  --muted: rgba(255, 255, 255, 0.72);
  --accent: #5aa6ff;
  --shadow: 0 10px 30px rgba(0,0,0,0.35);
  --radius: 18px;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans JP", sans-serif;
  color: var(--text);
  background: radial-gradient(1200px 700px at 20% 0%, rgba(90,166,255,0.20), transparent 55%),
              radial-gradient(900px 600px at 90% 10%, rgba(140,105,255,0.14), transparent 55%),
              var(--bg);
  line-height: 1.6;
}

.container {
  width: min(1100px, calc(100% - 32px));
  margin-inline: auto;
}

.site-header {
  padding: 28px 0 18px;
  border-bottom: 1px solid rgba(255,255,255,0.10);
  background: linear-gradient(to bottom, rgba(255,255,255,0.06), transparent);
}

.site-title {
  margin: 0 0 6px;
  font-size: clamp(24px, 3vw, 34px);
  letter-spacing: 0.02em;
}

.site-lead {
  margin: 0;
  color: var(--muted);
}

.site-note {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.toolbar {
  margin-top: 16px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 14px;
  border-radius: 999px;
  text-decoration: none;
  color: var(--text);
  background: rgba(90,166,255,0.20);
  border: 1px solid rgba(90,166,255,0.35);
  box-shadow: var(--shadow);
  transition: transform .15s ease, background .15s ease;
}
.btn:hover { transform: translateY(-1px); background: rgba(90,166,255,0.28); }

.filter {
  display: inline-flex;
  gap: 10px;
  align-items: center;
  padding: 8px 10px;
  border-radius: 999px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.10);
}
.filter-label { color: var(--muted); font-size: 0.92rem; }
.filter-select {
  background: transparent;
  color: var(--text);
  border: none;
  outline: none;
  font-size: 0.95rem;
}
.filter-select option { color: #111; }

.gallery {
  padding: 18px 0 34px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 14px;
}

.tile {
  position: relative;
  display: block;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
  border: 1px solid rgba(255,255,255,0.10);
  box-shadow: var(--shadow);
  text-decoration: none;
  transform: translateZ(0);
  transition: transform .18s ease, border-color .18s ease, background .18s ease;
}
.tile:hover {
  transform: translateY(-2px);
  border-color: rgba(90,166,255,0.40);
  background: var(--surface2);
}

.tile img {
  width: 100%;
  height: 160px;
  object-fit: cover;
  display: block;
}

.tile-caption {
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 10px;
  padding: 8px 10px;
  border-radius: 14px;
  background: rgba(0,0,0,0.45);
  backdrop-filter: blur(8px);
  color: rgba(255,255,255,0.92);
  font-size: 0.92rem;
}

.is-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  overflow: hidden !important;
  clip: rect(0 0 0 0) !important;
  clip-path: inset(50%) !important;
  white-space: nowrap !important;
}

.pagetop {
  margin: 0 0 34px;
  text-align: center;
}
.pagetop-link {
  display: inline-block;
  padding: 10px 14px;
  border-radius: 999px;
  color: var(--text);
  text-decoration: none;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.10);
}
.pagetop-link:hover { border-color: rgba(90,166,255,0.40); }

.site-footer {
  padding: 18px 0;
  border-top: 1px solid rgba(255,255,255,0.10);
  color: var(--muted);
}

/* スマホでの余白調整 */
@media (max-width: 480px) {
  .tile img { height: 150px; }
  .toolbar { justify-content: flex-start; }
}
``