:root {
  --primary: #547BFf;
  --white: #fff;
  --black: #000;
  --gray: #666;
  --light-gray: #f9f9f9;
  --dark-bg: #141d35;
  --blue-gradient: linear-gradient(90deg, #4fc3f7, #7b68ee);
}

/* 基础重置 */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Helvetica Neue', Helvetica, 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

body, html {
  width: 100%;
  height: 100%;
  font-size: 16px;
  color: var(--black);
  background-color: var(--light-gray);
  line-height: 1.5;
}

/* 布局容器 */
.layout {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

/* 响应式图片 */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* 链接样式 */
a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.3s ease;
}

a:hover {
  color: darken(var(--primary), 10%);
}

/* 按钮样式 */
.btn {
  display: inline-block;
  padding: 10px 20px;
  background: var(--primary);
  color: var(--white);
  border-radius: 4px;
  border: none;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn:hover {
  background: darken(var(--primary), 10%);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

/* 卡片样式 */
.card {
  background: var(--white);
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  padding: 20px;
  margin-bottom: 20px;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

/* 导航栏 */
.navbar {
  background: var(--white);
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  padding: 15px 0;
  position: fixed;
  width: 100%;
  top: 0;
  z-index: 1000;
}

.navbar .logo img {
  height: 40px;
}

.navbar .nav {
  display: flex;
  list-style: none;
}

.navbar .nav li {
  margin-left: 20px;
}

.navbar .nav a {
  color: var(--black);
  font-weight: 500;
  position: relative;
}

.navbar .nav a:after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width 0.3s ease;
}

.navbar .nav a:hover:after {
  width: 100%;
}

/* 响应式表格 */
.table-responsive {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

table th, table td {
  padding: 12px 15px;
  text-align: left;
  border-bottom: 1px solid #eee;
}

table tr:nth-child(even) {
  background: rgba(0,0,0,0.02);
}

/* 表单元素 */
input, textarea, select {
  width: 100%;
  padding: 10px 15px;
  border: 1px solid #ddd;
  border-radius: 4px;
  margin-bottom: 15px;
  transition: border-color 0.3s ease;
}

input:focus, textarea:focus, select:focus {
  border-color: var(--primary);
  outline: none;
}

/* 页脚 */
.footer {
  background: var(--dark-bg);
  color: var(--white);
  padding: 40px 0;
  text-align: center;
}

.footer a {
  color: var(--white);
}

/* 动画效果 */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.5s ease forwards;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .navbar {
    padding: 10px 0;
  }
  
  .navbar .nav {
    display: none;
  }
  
  .mobile-menu-btn {
    display: block;
  }
  
  .card {
    padding: 15px;
  }
  
  table th, table td {
    padding: 8px 10px;
    font-size: 14px;
  }
}

/* 工具类 */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-primary { color: var(--primary); }
.bg-white { background: var(--white); }
.mt-20 { margin-top: 20px; }
.mb-20 { margin-bottom: 20px; }
.p-20 { padding: 20px; }
.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-center { justify-content: center; }