* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Segoe UI', sans-serif;
  background-color: #f0f4f8;
  color: #333;
}

.navbar {
  background-color: #4a90e2;
  color: white;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.navbar h1 {
  font-size: 1.5rem;
  margin-right: 20px;
}

.navbar nav a {
  color: white;
  margin: 0 10px;
  padding: 8px 16px; /* 添加内边距，让按钮有更大的点击区域 */
  border-radius: 20px; /* 添加圆角 */
  text-decoration: none;
  font-weight: bold;
  transition: all 0.2s ease-in-out;
  background-color: rgba(255, 255, 255, 0.1); /* 添加半透明背景 */
}

.navbar nav a:hover,
.navbar nav a.active {
  background-color: rgba(255, 255, 255, 0.2); /* 悬停或激活时加深背景色 */
  opacity: 1;
  transform: translateY(-2px); /* 悬停时向上移动 */
}

.search-box {
  display: flex;
}

.search-box input {
  padding: 6px 10px;
  border: none;
  border-radius: 4px;
  width: 200px;
}

.app-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 20px;
  padding: 20px;
}

.app-card {
  text-align: center;
  background: white;
  padding: 15px;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
  transition: transform 0.2s;
}

.app-card:hover {
  transform: translateY(-5px);
}

.app-card img {
  width: 80px;
  height: 80px;
  object-fit: cover;
  border-radius: 10px;
  margin-bottom: 10px;
  border: 2px solid #eee;
}

.app-card p {
  font-size: 14px;
  margin-top: 5px;
}

.copyright {
  text-align: center;  /* 水平居中 */
  padding: 20px 0;
  margin-top: auto;    /* 垂直置底 */
  color: #666;
  position: relative;
  bottom: 0;
  width: 100%;
}

.category-filter {
  display: flex;
  justify-content: center;
  padding: 20px;
  gap: 10px;
}

.filter-btn {
  padding: 8px 16px;
  border: none;
  border-radius: 4px;
  background-color: #4a90e2;
  color: white;
  cursor: pointer;
  transition: all 0.2s ease-in-out;
}

.filter-btn:hover,
.filter-btn.active {
  background-color: #357abd;
}

.category-section {
  margin: 20px;
  padding: 20px;
  background-color: white;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.category-section h2 {
  margin-bottom: 15px;
  color: #4a90e2;
}

.download-btn {
  display: inline-block;
  margin-top: 10px;
  padding: 6px 12px;
  background-color: #4a90e2;
  color: white;
  text-decoration: none;
  border-radius: 4px;
  transition: background-color 0.2s;
}

.download-btn:hover {
  background-color: #357abf;
}


.category-container {
  padding: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: space-around;
}

.category-box {
  background-color: white;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  padding: 20px;
  width: calc(33.333% - 20px);
  min-width: 300px;
  transition: transform 0.2s ease-in-out;
}

.category-box:hover {
  transform: translateY(-5px);
}

.category-box h2 {
  color: #4a90e2;
  margin-bottom: 15px;
}

.app-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 15px;
}

.app-item {
  text-align: center;
}

.app-item img {
  width: 80px;
  height: 80px;
  object-fit: cover;
  border-radius: 10px;
  margin-bottom: 10px;
  border: 2px solid #eee;
}

.app-item p {
  font-size: 14px;
}