/* style.css */
/* 背景图（使用伪元素以便设置透明度） */
html,body{height: 100%;margin:0}
body{font-family:Segoe UI, Roboto, "Helvetica Neue", Arial, sans-serif;min-height:100%;position:relative}
body::before{
  content:"";
  position:fixed;inset:0;z-index:-1;
  background-image: url('N3.png');
  background-size: cover;
  background-position: center center;
  opacity: 0.8; /* 背景透明度 0.8 */
  pointer-events: none;
}

/* 左侧竖向导航栏 */
.sidebar{
  position:fixed;
  left:0;top:0;bottom:0;
  width: 100px; /* 指定宽度 100px */
  display:flex;
  align-items:center;
  justify-content:center;
  background: rgba(0, 0, 0, 0); /* 半透明底，提升可读性，可调 */
  backdrop-filter: blur(4px);
  box-shadow: 2px 0 8px rgba(0, 0, 0, 0.093);
  z-index: 1000;
}
.sidebar nav{display:flex;flex-direction:column;align-items:center;gap:25px;padding:20px 0}

/* 导航项：文字保持横向排列（默认行为），居中显示 */
.nav-item{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  width:100%;
  color:#fff;
  text-decoration:none;
  font-size:13px;
  white-space:nowrap; /* 保持横向不换行 */
  padding:6px 4px;
  border-radius:6px;
  transition:background .18s,color .18s,transform .15s;
  text-align:center;
  user-select:none;
}
.nav-item:hover,
.nav-item:focus{
  background: rgba(255,255,255,0.08);
  color:#fff;
  transform:translateX(2px);
  outline:none;
}
.nav-item.active{background:linear-gradient(90deg,#6C63FF,#ff7a59);color:#fff}

/* Banner图区域 */
.banner {
  width: 100%;
  overflow: hidden;
  margin-bottom: 30px;
  text-align: center;
}

.banner img {
  width: 90%;
  height: auto;
  display: block;
  margin-left: auto;
  margin-right: auto;
  border-radius: 12px;
}

/* 主内容区 */
main.content {
  padding: 40px 20px;
  margin-left: 100px; /* 留出侧边栏宽度 */
  margin-right: auto;
  max-width: 1200px;
  width: calc(100% - 100px); /* 计算可用宽度，减去侧边栏宽度 */
  box-sizing: border-box;
}

.content h1 {
  text-align: center;
  color: #ff977d;
  margin-bottom: 40px;
  font-size: 32px;
}

/* 内容网格布局 */
.content-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin-top: 30px;
}

.content-item {
  background: rgba(255, 255, 255, 0.9);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.content-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.content-item img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  display: block;
}

.content-item h3 {
  padding: 20px 20px 10px;
  margin: 0;
  color: #333;
  font-size: 20px;
}

.content-item p {
  padding: 0 20px 20px;
  margin: 0;
  color: #666;
  line-height: 1.6;
}

/* 底部样式 */
.footer {
  background: rgba(154, 140, 140, 0.25);
  backdrop-filter: blur(4px);
  text-align: center;
  padding: 20px;
  margin-top: 40px;
  margin-left: 100px; /* 留出侧边栏宽度 */
  color: #fff;
  font-size: 14px;
}

/* 小屏幕响应式设计 */
@media (max-width: 768px) {
  .sidebar {
    display: none;
  }
  
  main.content {
    margin-left: 0;
    padding: 20px 15px;
  }
  
  .footer {
    margin-left: 0;
  }
  
  .content h1 {
    font-size: 24px;
  }
  
  .content-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}

/* 上传进度条样式 */
.upload-progress {
  text-align: center;
  margin: 10px 0;
  color: #ff7a59;
  font-size: 14px;
  display: none;
  padding: 10px;
}

.progress-bar-container {
  width: 100%;
  height: 8px;
  background-color: rgba(0,0,0,0.08);
  border-radius: 4px;
  margin: 8px 0;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background-color: #ff7a59;
  width: 0%;
  transition: width 0.3s ease;
  border-radius: 4px;
}

.progress-text {
  font-size: 13px;
  font-weight: 500;
}