* { box-sizing: border-box; }
a { color:#fff; text-decoration:none; }

nav {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(17,17,17,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 0 1.2rem;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  z-index: 1000;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.nav-logo {
  display: flex;
  align-items: center;
  height: 100%;
}

.nav-logo img {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  object-fit: cover;
}

/* デスクトップ用リンクは常に非表示 */
.nav-links {
  display: none;
}

/* ハンバーガーは常に表示 */
.nav-hamburger {
  display: flex;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 6px;
  border-radius: 8px;
  transition: background 0.2s;
}

.nav-hamburger:hover {
  background: rgba(255,255,255,0.1);
}

.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.nav-mobile-menu {
  display: none;
  position: fixed;
  top: 52px;
  left: 0;
  width: 100%;
  background: rgba(17,17,17,0.97);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  z-index: 999;
  flex-direction: column;
  padding: 0.5rem 0;
  animation: slideDown 0.2s ease;
}

@keyframes slideDown {
  from { opacity:0; transform:translateY(-8px); }
  to   { opacity:1; transform:translateY(0); }
}

.nav-mobile-menu.open { display: flex; }

.nav-mobile-menu a {
  padding: 1rem 1.8rem;
  font-size: 1.05rem;
  font-weight: bold;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  transition: background 0.15s;
  color: #fff;
}

.nav-mobile-menu a:last-child { border-bottom: none; }
.nav-mobile-menu a:hover { background: rgba(255,255,255,0.06); }