/* 文章页样式：浅色为默认，深色跟随系统，也可以用页面右上角按钮手动切换。 */

:root {
  --bg: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --link: #0969da;
  --border: #e5e7eb;
  --surface: #f6f8fa;
  --shadow: 0 1px 3px rgba(15, 23, 42, 0.12);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #16181d;
    --text: #e6e8eb;
    --muted: #9aa1ab;
    --link: #6cb6ff;
    --border: #333841;
    --surface: #21242b;
    --shadow: none;
  }
}

:root[data-theme="dark"] {
  --bg: #16181d;
  --text: #e6e8eb;
  --muted: #9aa1ab;
  --link: #6cb6ff;
  --border: #333841;
  --surface: #21242b;
  --shadow: none;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: system-ui, sans-serif;
  line-height: 1.75;
}

.site-header,
.article-layout {
  width: min(1120px, calc(100% - 32px));
  margin: auto;
}

.site-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 20px;
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
}

.site-header a {
  color: var(--link);
  text-decoration: none;
}

.site-header a:hover {
  text-decoration: underline;
}

.theme-toggle {
  margin-left: auto;
  padding: 6px 14px;
  font: inherit;
  font-size: 14px;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
}

.theme-toggle:hover {
  border-color: var(--link);
}

/* 顶部阅读进度条 */
.read-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 20;
  width: 0;
  height: 3px;
  background: var(--link);
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.article {
  min-width: 0;
  padding: 32px 0 80px;
}

/* 窄屏不放目录；脚本没跑或标题太少时它是空的。 */
.toc {
  display: none;
}

.toc:not(:empty) {
  font-size: 14px;
}

@media (min-width: 1040px) {
  .article-layout {
    grid-template-columns: minmax(0, 1fr) 230px;
    gap: 48px;
  }

  .toc:not(:empty) {
    display: block;
    position: sticky;
    top: 24px;
    align-self: start;
    max-height: calc(100vh - 48px);
    overflow: auto;
    padding: 32px 0;
  }
}

.toc-title {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 13px;
}

.toc ul {
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 1px solid var(--border);
}

.toc li {
  margin: 2px 0;
}

.toc a {
  display: block;
  margin-left: -1px;
  padding: 4px 0 4px 12px;
  color: var(--muted);
  text-decoration: none;
  border-left: 2px solid transparent;
}

.toc a:hover {
  color: var(--text);
}

.toc a.on {
  color: var(--link);
  border-left-color: var(--link);
  font-weight: 600;
}

.toc-h3 a {
  padding-left: 26px;
  font-size: 13px;
}

.article h2,
.article h3 {
  scroll-margin-top: 16px;
}

pre {
  position: relative;
  overflow-x: auto;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
}

code {
  font-family: Consolas, monospace;
}

.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 3px 10px;
  font: inherit;
  font-size: 12px;
  color: var(--muted);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  opacity: 0.6;
  transition: opacity 0.15s;
}

pre:hover .copy-btn,
.copy-btn:focus-visible {
  opacity: 1;
}

.copy-btn.done {
  color: var(--link);
  border-color: var(--link);
  opacity: 1;
}

table {
  display: block;
  max-width: 100%;
  overflow-x: auto;
  border-collapse: collapse;
}

th,
td {
  padding: 8px 12px;
  border: 1px solid var(--border);
}

blockquote {
  margin: 16px 0;
  padding: 4px 16px;
  color: var(--muted);
  border-left: 3px solid var(--border);
}

img {
  max-width: 100%;
}

a {
  color: var(--link);
}

hr {
  border: none;
  border-top: 1px solid var(--border);
}

.to-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 20;
  width: 40px;
  height: 40px;
  font: inherit;
  font-size: 18px;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 50%;
  box-shadow: var(--shadow);
  cursor: pointer;
}

.to-top:hover {
  border-color: var(--link);
}