/* FactorMath 暖金主题 (pure.css base) */
:root {
  --theme-color: #d97706;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: #ffffff;
  color: #2d3748;
  font-size: 16px;
  line-height: 1.85;
}

/* 侧边栏 */
.sidebar {
  background-color: #f7f4eb;
  border-right: 1px solid #e2dbaa;
}

.sidebar-nav ul li a {
  color: #4a5568;
  font-size: 15px;
  padding: 8px 15px;
  line-height: 1.4;
  text-decoration: none;
  transition: color 0.2s ease;
}

.sidebar-nav ul li a:hover {
  color: var(--theme-color);
  text-decoration: none;
}

.sidebar-nav ul li.active > a {
  color: #b45309;
  font-weight: bold;
  background-color: #ffffff;
  border-right: 3px solid #b45309;
  border-radius: 4px 0 0 4px;
}

.sidebar .sidebar-nav strong {
  color: #78350f;
  display: block;
  margin-top: 18px;
  margin-bottom: 6px;
  font-size: 14px;
}

.sidebar .search input {
  background-color: #ffffff;
  border: 1px solid #e2dbaa;
  border-radius: 4px;
}

/* 侧边栏 toggle 按钮（仅桌面端对齐） */
@media screen and (min-width: 769px) {
  .sidebar-toggle {
    width: 300px;
    border-right: 1px solid #e2dbaa;
  }
}

/* 内容区域 */
.markdown-section {
  max-width: 820px;
  padding: 40px 30px 100px 30px;
  background-color: #ffffff;
}

.markdown-section h1,
.markdown-section h2,
.markdown-section h3 {
  color: #1a202c;
  font-weight: 700;
}

.markdown-section h1 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
}

.markdown-section h2 {
  font-size: 1.45rem;
  border-bottom: 1px solid #edf2f7;
  padding-bottom: 0.4rem;
  margin-top: 2.2rem;
}

.markdown-section a {
  color: var(--theme-color);
}

/* KaTeX 公式 */
.katex-display {
  padding: 12px 0;
  margin: 1.5em 0;
  background-color: #f7fafc;
  border-radius: 6px;
  overflow-x: auto;
  overflow-y: hidden;
  max-width: 100%;
  box-sizing: border-box;
}

.katex {
  font-size: 1.06em;
}

/* 引用框 */
.markdown-section blockquote {
  border-left: 4px solid #d97706;
  background-color: #fcf9f2;
  color: #4a5568;
  padding: 15px 20px;
  border-radius: 0 6px 6px 0;
  margin: 1.8em 0;
}

/* 页脚 */
.site-footer {
  font-size: 0.9em;
  color: #718096;
  text-align: center;
  padding: 20px 0;
}

.site-footer strong {
  color: #b45309;
}

hr {
  border: 0;
  border-top: 1px solid #edf2f7;
  margin: 4em 0 1em 0;
}

/* 移动端 */
@media screen and (max-width: 768px) {
  body { font-size: 15.5px; }
  .markdown-section { padding: 25px 20px 60px 20px; }
}