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

body {
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f5f5f5;
}

/* 导航栏 */
header {
  background-color: #2c3e50;
  color: #fff;
  padding: 16px 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

nav {
  max-width: 1000px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
}

.logo {
  font-size: 20px;
  font-weight: bold;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 24px;
}

nav a {
  color: #fff;
  text-decoration: none;
  transition: color 0.3s;
}

nav a:hover {
  color: #3498db;
}

/* 主视觉区 */
.hero {
  background: linear-gradient(135deg, #3498db, #2c3e50);
  color: #fff;
  text-align: center;
  padding: 100px 20px;
}

.hero h1 {
  font-size: 42px;
  margin-bottom: 16px;
}

.hero p {
  font-size: 18px;
  margin-bottom: 28px;
  opacity: 0.9;
}

.btn {
  display: inline-block;
  background-color: #fff;
  color: #2c3e50;
  padding: 12px 32px;
  border-radius: 6px;
  text-decoration: none;
  font-weight: bold;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

/* 内容区 */
main {
  max-width: 1000px;
  margin: 0 auto;
  padding: 60px 20px;
}

section {
  margin-bottom: 60px;
}

h2 {
  font-size: 28px;
  margin-bottom: 20px;
  border-left: 5px solid #3498db;
  padding-left: 12px;
}

/* 卡片布局 */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.card {
  background: #fff;
  padding: 24px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  transition: transform 0.2s;
}

.card:hover {
  transform: translateY(-4px);
}

.card h3 {
  margin-bottom: 8px;
  color: #2c3e50;
}

/* 表单 */
.form-group {
  margin-bottom: 16px;
}

label {
  display: block;
  margin-bottom: 6px;
  font-weight: bold;
  font-size: 14px;
}

input, textarea {
  width: 100%;
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-family: inherit;
  font-size: 14px;
}

input:focus, textarea:focus {
  outline: none;
  border-color: #3498db;
}

/* 页脚 */
footer {
  background-color: #2c3e50;
  color: #bbb;
  text-align: center;
  padding: 24px 20px;
  font-size: 14px;
}