body {
  margin: 0;
  font-family: 'Roboto', sans-serif;
  background: linear-gradient(to bottom right, #fff176, #ffffff);
  min-height: 100vh;
}

.logo-button {
  position: fixed;
  top: 50px;
  left: 50px;
  z-index: 100;
}

.logo-button img {
  width: 150px;
  height: auto;
  cursor: pointer;
}

.top-text {
  text-align: center;
  font-size: 1.5rem;
  color: #1E90FF;
  margin: 2rem auto;
  line-height: 1.6rem;
}

.spacer {
  height: 100vh;
}

.section-title {
  text-align: center;
  font-size: 3rem;
  font-weight: bold;
  color: #1E90FF;
  margin-top: 2rem;
}

.files-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
  padding: 2rem 0 5rem 0;
}

.file-card {
  width: 300px;
  background: #ffffffdd;
  border-radius: 15px;
  box-shadow: 0 12px 30px rgba(0,0,0,0.25);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.file-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 16px 40px rgba(0,0,0,0.35);
}

.file-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.file-card h3,
.file-card p,
.file-card a {
  text-align: center;
  margin: 0.5rem 1rem;
}

.file-card a {
  color: #1E90FF;
  text-decoration: none;
  margin-bottom: 1rem;
}

.file-card a:hover {
  text-decoration: underline;
}

#overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.7);
  display: flex;
  justify-content: center;
  align-items: center;
}

#overlay.hidden {
  display: none;
}

.overlay-content {
  background: #fff;
  border-radius: 20px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  max-height: 80%;
  max-width: 90%;
  width: 800px;
  box-shadow: 0 0 20px rgba(0,0,0,0.5);
}

#closeOverlay {
  align-self: flex-end;
  background: none;
  border: none;
  font-size: 2rem;
  cursor: pointer;
}

.button-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  overflow-y: auto;
  max-height: 300px;
  margin-bottom: 1rem;
  width: 100%;
  justify-content: center;
}

.button-list button {
  background: #1E90FF;
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 10px;
  color: white;
  cursor: pointer;
  transition: background 0.2s;
}

.button-list button:hover {
  background: #1565c0;
}

.frame-wrapper {
  position: relative;
  width: 100%;
}

#gameFrame {
  width: 100%;
  height: 400px;
  border: none;
  border-radius: 10px;
  display: block;
}

#fullscreenBtn {
  position: absolute;
  top: 15px;
  right: 15px;
  width: 50px;
  height: 50px;
  background: rgba(30, 144, 255, 0.9);
  color: white;
  font-size: 1.5rem;
  font-weight: bold;
  border: none;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 10px rgba(0,0,0,0.4);
  z-index: 9999;
  transition: transform 0.2s ease, background 0.2s ease;
}

#fullscreenBtn:hover {
  background: rgba(30, 144, 255, 1);
  transform: scale(1.1);
}