/* 基础样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* 全局样式 */
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
  padding: 20px;
}

/* 导航栏样式 */
nav {
  background-color: #343a40;
  padding: 1rem;
  margin-bottom: 2rem;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 1rem;
}

nav a {
  color: white;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
}

nav a:hover {
  background-color: #495057;
}

/* 容器样式 */
.container {
  max-width: 1200px;
  margin: 0 auto;
}

/* 标题样式 */
h1, h2, h3 {
  margin-bottom: 1rem;
  color: #2d3436;
}

/* 表格样式 */
table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1rem;
}

table th, table td {
  padding: 0.75rem;
  text-align: left;
  border-bottom: 1px solid #dee2e6;
}

table th {
  background-color: #e9ecef;
}

/* 按钮样式 */
.btn {
  display: inline-block;
  font-weight: 400;
  text-align: center;
  white-space: nowrap;
  vertical-align: middle;
  user-select: none;
  border: 1px solid transparent;
  padding: 0.375rem 0.75rem;
  font-size: 1rem;
  line-height: 1.5;
  border-radius: 0.25rem;
  transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out;
}

.btn-primary {
  color: #fff;
  background-color: #007bff;
  border-color: #007bff;
}

.btn-secondary {
  color: #fff;
  background-color: #6c757d;
  border-color: #6c757d;
}

/* 表单样式 */
.form-group {
  margin-bottom: 1rem;
}

label {
  display: inline-block;
  margin-bottom: 0.5rem;
}

input, textarea, select {
  display: block;
  width: 100%;
  padding: 0.375rem 0.75rem;
  font-size: 1rem;
  line-height: 1.5;
  color: #495057;
  background-color: #fff;
  border: 1px solid #ced4da;
  border-radius: 0.25rem;
}

/* 卡片样式 */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  min-width: 0;
  word-wrap: break-word;
  background-color: #fff;
  background-clip: border-box;
  border: 1px solid rgba(0, 0, 0, 0.125);
  border-radius: 0.25rem;
  margin-bottom: 1rem;
}

.card-body {
  flex: 1 1 auto;
  padding: 1.25rem;
}

.card-title {
  margin-bottom: 0.75rem;
}

/* 响应式样式 */
@media (max-width: 768px) {
  nav ul {
    flex-direction: column;
  }
}