/* ===== 1. 整个表格的整体设置 ===== */
table {
  border-collapse: collapse;
  width: 100%;
  max-width: 900px;
  margin: 30px auto;
  font-family: system-ui, "Microsoft YaHei", sans-serif;
  font-size: 16px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}

/* ===== 2. 所有格子：边框 + 内边距 + 居中 ===== */
th, td {
  border: 1px solid #e0e0e0;
  padding: 14px 12px;
  text-align: center;
}

/* ===== 3. 表头格子：蓝色背景 + 白字 ===== */
thead th {
  background-color: #4a90d9;
  color: #ffffff;
  font-weight: 600;
  letter-spacing: 1px;
}

/* ===== 4. 每行第一格（节次列）：浅灰底 + 加粗 ===== */
tbody td:first-child {
  background-color: #f7f9fc;
  color: #333333;
  font-weight: 600;
}

/* ===== 5. 鼠标移到数据行上：浅蓝高亮 ===== */
tbody tr:hover td {
  background-color: #eaf3fc;
}
/* ===== 表单样式 ===== */
.form-container {
  max-width: 900px;
  margin: 30px auto 0;
  padding: 20px;
  background-color: #ffffff;
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  font-family: system-ui, "Microsoft YaHei", sans-serif;
}
.form-container h3 { margin-top: 0; color: #333; }
#add-course-form {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
#add-course-form input,
#add-course-form select {
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 4px;
  flex: 1;
  min-width: 120px;
}
#add-course-form button {
  padding: 10px 20px;
  background-color: #4a90d9;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  flex: 0 0 auto;
}
#add-course-form button:hover {
  background-color: #357abd;
}