/* --- 全局字体和排版 --- */
body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: #222;
  background: #fafafa;
  margin: 1.5rem 3rem;
}

.md-header, .md-footer, .md-nav, .md-sidebar {
  display: none !important;
}

.md-main {
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 2.5rem;
  background: #fff;
  box-shadow: 0 8px 20px rgba(0,0,0,0.08);
  border-radius: 10px;
  border: 1px solid #e0e0e0;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  color: #000000;
  margin-top: 2.2rem;
  margin-bottom: 1rem;
  letter-spacing: 0.02em;
  line-height: 1.4;
  text-rendering: optimizeLegibility;
  font-feature-settings: "liga";
  font-smooth: always;
}

h1 {
  font-size: 2.2rem;
}

h2 {
  font-size: 1.8rem;
}

h3 {
  font-size: 1.5rem;
}

p {
  margin-bottom: 0.8rem;
  color: #333333;
  letter-spacing: 0.01em;
}

ul, ol {
  margin-left: 1.8rem;
  margin-bottom: 1.8rem;
  color: #444444;
  letter-spacing: 0.02em;
  line-height: 1.6;
}

a {
  color: #1a73e8;
  text-decoration: none;
  font-weight: 600;
  transition: all 0.25s ease;
}

a:hover, a:focus {
  text-decoration: underline;
  color: #155ab6;
}

blockquote {
  border-left: 5px solid #1a73e8;
  margin: 1.8rem 0;
  padding-left: 1.2rem;
  color: #555555;
  font-style: italic;
  background: #e8f0fe;
  border-radius: 6px;
  font-size: 1.05rem;
}

code {
  background: #f5f5f5;
  padding: 3px 7px;
  border-radius: 5px;
  font-family: "Courier New", Courier, monospace;
  font-size: 0.95em;
  color: #c7254e;
}

pre {
  background: #f6f8fa;
  color: #333;
  padding: 1.2rem 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  font-family: "Courier New", Courier, monospace;
  font-size: 0.9em;
  line-height: 1.5;
  box-shadow: none;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 2rem;
  font-size: 1rem;
}

th, td {
  border: 1px solid #ddd;
  padding: 12px 16px;
  text-align: left;
}

th {
  background-color: #f0f0f0;
  font-weight: 800;
  color: #000000;
}

img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  margin: 1.5rem 0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

a:focus, button:focus, input:focus, textarea:focus {
  outline: none;
  box-shadow: 0 0 6px 3px rgba(26, 115, 232, 0.5);
}
