/**
 * Premium SEO Template - CSS Reset
 * 现代化的CSS重置，为所有浏览器提供一致的基础样式
 */

/* 基础元素重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

*::before,
*::after {
  box-sizing: border-box;
}

/* HTML和Body */
html {
  height: 100%;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
  scroll-behavior: smooth;
}

body {
  height: 100%;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
  font-size: 14px;
  line-height: 1.6;
  color: #333;
  background-color: #f5f5f5;
  word-wrap: break-word;
  word-break: break-word;
}

/* 标题 */
h1, h2, h3, h4, h5, h6 {
  margin: 0;
  padding: 0;
  font-weight: 600;
  line-height: 1.2;
}

h1 { font-size: 32px; }
h2 { font-size: 28px; }
h3 { font-size: 24px; }
h4 { font-size: 20px; }
h5 { font-size: 16px; }
h6 { font-size: 14px; }

/* 段落 */
p {
  margin: 0;
  padding: 0;
}

/* 列表 */
ul, ol, dl {
  margin: 0;
  padding: 0;
  list-style: none;
}

li {
  list-style: none;
}

dt {
  font-weight: 600;
}

dd {
  margin: 0;
}

/* 链接 */
a {
  color: #0066cc;
  text-decoration: none;
  background-color: transparent;
  cursor: pointer;
  transition: color 0.3s ease, background-color 0.3s ease;
}

a:hover {
  color: #0052a3;
  text-decoration: underline;
}

a:active {
  color: #003d7a;
}

a:focus {
  outline: 2px solid #0066cc;
  outline-offset: 2px;
}

/* 图片 */
img {
  max-width: 100%;
  height: auto;
  display: block;
  border: 0;
  vertical-align: middle;
}

/* 表单元素 */
button, input, select, textarea {
  margin: 0;
  padding: 0;
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
  color: inherit;
  background: transparent;
  border: 0;
  outline: 0;
}

button {
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"],
input[type="number"],
textarea,
select {
  -webkit-appearance: none;
  appearance: none;
  border: 1px solid #ddd;
  border-radius: 4px;
  padding: 8px 12px;
  font-size: 14px;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="password"]:focus,
input[type="search"]:focus,
input[type="number"]:focus,
textarea:focus,
select:focus {
  border-color: #0066cc;
  box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

textarea {
  resize: vertical;
  overflow: auto;
}

/* 表格 */
table {
  border-collapse: collapse;
  border-spacing: 0;
  width: 100%;
}

th, td {
  padding: 8px;
  text-align: left;
  border-bottom: 1px solid #ddd;
}

th {
  font-weight: 600;
  background-color: #f9f9f9;
}

/* 代码 */
code, pre, kbd, samp {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.875em;
}

code {
  background-color: #f5f5f5;
  padding: 2px 6px;
  border-radius: 3px;
}

pre {
  background-color: #f5f5f5;
  padding: 12px;
  border-radius: 4px;
  overflow: auto;
}

/* 引用 */
blockquote {
  margin: 0;
  padding: 0 0 0 12px;
  border-left: 4px solid #0066cc;
}

/* 水平线 */
hr {
  margin: 20px 0;
  border: 0;
  border-top: 1px solid #ddd;
  height: 0;
  overflow: visible;
}

/* 清除浮动 */
.clearfix::after,
.clearfix::before {
  content: " ";
  display: table;
}

.clearfix::after {
  clear: both;
}

/* 隐藏元素 */
.hidden,
[hidden] {
  display: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* 容器 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

/* 行和列 */
.row {
  display: flex;
  flex-wrap: wrap;
  margin: 0 -15px;
}

.col {
  flex: 1;
  padding: 0 15px;
}

/* 响应式工具 */
@media (max-width: 768px) {
  h1 { font-size: 24px; }
  h2 { font-size: 20px; }
  h3 { font-size: 18px; }
  h4 { font-size: 16px; }
  h5 { font-size: 14px; }
  h6 { font-size: 12px; }

  body {
    font-size: 13px;
  }
}

@media (max-width: 480px) {
  h1 { font-size: 20px; }
  h2 { font-size: 18px; }
  h3 { font-size: 16px; }
  h4 { font-size: 14px; }
  h5 { font-size: 12px; }
  h6 { font-size: 11px; }

  body {
    font-size: 12px;
  }
}