* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Arial', sans-serif;
  background: linear-gradient(to bottom, #1e0033, #33004d);
  color: #fff;
  overflow-x: hidden;
}

#top-nav {
  position: fixed;
  top: 0;
  width: 100%;
  background: #000;
  z-index: 1000;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  padding: 0.5rem;
  gap: 0.5rem;
}

#top-nav a {
  padding: 0.4rem 1rem;
  background: #111;
  color: #00ffff;
  text-decoration: none;
  border: 1px solid #00ffff;
  border-radius: 10px;
  transition: all 0.3s ease;
  font-size: 0.9rem;
}

#top-nav a:hover {
  background: #00ffff;
  color: #000;
}

#banner {
  margin-top: 70px;
  width: 100%;
  max-height: 500px;
  overflow: hidden;
}

#banner img {
  width: 100%;
  height: auto;
  display: block;
}

.tab-section {
  display: none;
}

#container {
  text-align: center;
  padding: 1rem;
  max-width: 100%;
}

#logo {
  width: 160px;
  margin: 1rem auto 0.5rem auto;
  display: block;
}

h1 {
  font-size: 2rem;
  color: #ff66cc;
  margin: 0.2rem;
}

h2 {
  font-size: 1.2rem;
  color: #9990ff;
  margin: 0.2rem;
}

.slogan {
  font-style: italic;
  color: #ccc;
  margin: 1rem 0;
}

#partyBtn {
  font-size: 1rem;
  padding: 0.8rem 1.5rem;
  border-radius: 12px;
  border: none;
  background: linear-gradient(to right, #00ffff, #00cc99);
  color: #000;
  cursor: pointer;
  font-weight: bold;
}

#gif-gallery {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.8rem;
}

.party-gif {
  width: 90px;
  border-radius: 10px;
  box-shadow: 0 0 10px #000;
}

#info-content {
  max-width: 600px;
  margin: auto;
  font-size: 1rem;
  padding: 1rem;
  text-align: left;
}

#info-content a {
  color: #00ffff;
  text-decoration: none;
}

#info-content a:hover {
  text-decoration: underline;
}

@media (max-width: 600px) {
  h1 { font-size: 1.5rem; }
  h2 { font-size: 1rem; }
  .slogan { font-size: 0.9rem; }
  #partyBtn { font-size: 0.9rem; }
}

#gif-gallery.party-mode {
  animation: flashGlow 1.2s infinite alternate;
}

@keyframes flashGlow {
  0% {
    background-color: rgba(0, 255, 255, 0.05);
    box-shadow: 0 0 10px rgba(0, 255, 255, 0.3);
  }
  100% {
    background-color: rgba(255, 0, 255, 0.05);
    box-shadow: 0 0 20px rgba(255, 0, 255, 0.4);
  }
}