:root {
  --color-primary: #482936;
  --color-gray: #777;
  --color-gray-20: rgba(0, 0, 0, 0.2);
  --font-family-primary:
    alegreya, jinkaiFont, Georgia, Cambria, "Times New Roman", serif;
  --font-family-secondary: "Alkatra", serif;
  --font-family-medium:
    moniker-medium, jinkaiFont, Georgia, Cambria, "Times New Roman", serif;
  --font-family-title: "ReallySansLarge", jinkaiFont, serif;
  --font-weight-title-bold: 700;
  --color-text-shadow: rgba(0, 0, 0, 0.15); /* 示例：更柔和的阴影颜色 */
  --header-title-size-default: 2.5rem;
  --header-title-size-medium: 3rem;
  --header-title-size-large: 3.5rem;
}

html {
  /* Make the element's width and height include padding and border,
       rather than adding them outside,
       for more intuitive layout calculations. */
  box-sizing: border-box;
  /* (commonly 16px) */
  font-size: 100%;
}

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

body {
  margin: 0 auto; /* 更明确垂直边距为0，水平自动 */
  padding: 1.25rem; /* 使用 rem (假设 1rem = 16px, 20/16 = 1.25) */
  max-width: 55rem; /* 使用 rem (720px / 16px = 45rem) */
  font-family: var(--font-family-primary);
  font-size: 1.1875rem; /* 使用 rem (19px / 16px = 1.1875) */
  line-height: 1.6; /* 保持无单位行高 */
  background-color: var(--color-background, white); /* 建议显式设置背景色 */
  color: var(--color-text, #333); /* 建议显式设置默认文本颜色 */
  overflow-wrap: break-word; /* 的作用是允许在单词内部进行换行，以防止长单词或 URL 溢出其容器。 */
}

/* Header */
.header-title {
  font-family: var(--font-family-secondary);
  /* font-size: 3rem; */
  font-weight: var(--font-weight-title-bold);
  text-decoration: none;
  /* text-shadow: var(--color-text-shadow) 4px 4px 4px #aaa; */
  font-size: var(--header-title-size-large);
  text-shadow: 3px 3px 5px var(--color-text-shadow);
}

.header-line {
  width: 100%;
  margin-top: 2rem;
  border-width: 2px;
  border-style: solid none none none;
  border-color: var(--color-primary);
}

#preamble {
  position: relative;
}

/* Headline */

h1,
h2,
h3 {
  font-family: var(--font-family-title);
}

.page-item {
  display: flex;
  align-items: center;
  justify-content: space-between; /* 保持，首尾元素靠两边 */
}

/* categories */
.categories {
  min-width: 10rem;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(5rem, 1fr));
  gap: 0.5rem;
  align-items: center;
}

@media (max-width: 768px) {
  .categories {
    grid-template-columns: repeat(auto-fill, minmax(3rem, 1fr));
  }
}

.category-item a {
  text-decoration: none;
}

.category-item {
  display: flex; /* 使自身成为flex容器，用于其内部内容的对齐 */
  align-items: center; /* 垂直居中内部内容 */
  justify-content: center; /* 水平居中内部内容 */
  border: #000 1px solid;
  border-radius: 3px;
  padding: 0.3rem;
  font-size: 0.8rem;
  font-weight: bold;
}

.page-item .categories {
  justify-content: right;
}

.page-item .categories .category-item {
  padding: 0.2rem;
  font-size: 0.7rem;
}

li {
  margin: 0.4rem 0;
}

img {
  width: 100%;
}

.figure {
  font-size: 0.8rem;
  text-align: center;
}

pre {
  width: 100%;
}

.footer-line {
  width: 100%;
  margin-top: 1.5rem;
  margin-bottom: 1.5rem;
  border-width: 2px;
  border-style: solid none none none;
  border-color: var(--color-primary);
}

footer {
  text-align: center;
}

.hidden {
  display: none;
}

.hidden-checkbox {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
  margin: 0;
}

.hidden-checkbox:checked + .custom-label {
  color: white;
  background-color: green;
}

/* Label 的基础样式 */
.custom-label {
  display: inline-block;
  cursor: pointer; /* 让鼠标变成小手 */
  user-select: none; /* 防止双击选中文本 */
}

.item-left {
  display: flex;
  flex-direction: row;
}

.date-item {
  font-feature-settings: "tnum";
  font-variant-numeric: tabular-nums;
  flex-basis: 5em;
  min-width: 5em;
  flex-shrink: 0;
}

.index-container {
  display: flex;
  flex-direction: column;
  text-align: center;
}

.more-posts {
  border-color: #111827;
}

@media (max-width: 768px) {
  .page-item .categories {
    display: none;
  }
}