* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", sans-serif;
  background: #111;
  color: #eee;
  overflow-x: hidden;
}

img {
  max-width: 100%;
  height: auto;
}

/* 落下ロゴコンテナ（全画面・背面） */
.logo-fall-container {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

/* 落下するロゴ */
.logo-fall {
  position: absolute;
  width: 80px;
  opacity: 0.25;
  animation: logoFall 8s linear infinite;
}

@keyframes logoFall {
  0% {
    transform: translateY(-120px) rotate(0deg);
    opacity: 0;
  }
  10% {
    opacity: 0.25;
  }
  100% {
    transform: translateY(110vh) rotate(360deg);
    opacity: 0;
  }
}

.header {
  position: relative;
  z-index: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  padding: 20px 40px;
  background: #000;
  border-bottom: 1px solid #333;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 2px;
}

.brand-logo {
  height: 32px;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.nav a {
  color: #ccc;
  text-decoration: none;
  font-size: 14px;
}

.hero {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 120px 20px;
  background: linear-gradient(135deg, #222, #000);
}

.hero-logo-wrapper {
  margin-bottom: 40px;
}

.hero-logo {
  width: 260px;
  max-width: 80%;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  margin-bottom: 10px;
}

.hero p {
  font-size: clamp(1rem, 2.2vw, 1.2rem);
}

.products {
  position: relative;
  z-index: 1;
  padding: 60px 40px;
}

.product-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
}

.product-card {
  background: #1a1a1a;
  padding: 20px;
  border-radius: 12px;
  border: 1px solid #333;
}

.product-card img {
  width: 100%;
  border-radius: 8px;
  margin-bottom: 15px;
}

.btn {
  display: inline-block;
  padding: 10px 20px;
  background: #444;
  color: #fff;
  border-radius: 6px;
  text-decoration: none;
  transition: 0.2s;
}

.btn:hover {
  background: #666;
}

.about, .contact {
  position: relative;
  z-index: 1;
  padding: 60px 40px;
}

.about p,
.contact p {
  max-width: 760px;
  line-height: 1.8;
}

.footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 20px;
  border-top: 1px solid #333;
  background: #000;
}

@media (max-width: 768px) {
  .header {
    padding: 16px 20px;
  }

  .nav {
    width: 100%;
    justify-content: center;
  }

  .hero {
    padding: 90px 20px;
  }

  .products,
  .about,
  .contact {
    padding: 48px 20px;
  }
}

@media (max-width: 480px) {
  .brand {
    font-size: 16px;
  }

  .brand-logo {
    height: 24px;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

  .hero p {
    font-size: 0.95rem;
  }

  .product-card {
    padding: 16px;
  }

  .btn {
    width: 100%;
    text-align: center;
  }
}