:root {
  color-scheme: light;
  --paper: #ffffff;
  --ink: #262626;
  --muted: #8c8c8c;
  --line: #e7e9e8;
  --soft: #f7f8fa;
  --accent: #167c80;
  --accent-2: #6b7280;
  --max: 820px;
  --article: 760px;
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue",
    Helvetica, Arial, sans-serif, "Segoe UI";
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 15.5px;
  line-height: 1.76;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration-color: rgba(49, 95, 101, 0.35);
  text-underline-offset: 0.24em;
}

a:hover {
  color: var(--accent);
  text-decoration-color: currentColor;
}

.page-shell {
  width: min(100% - 48px, var(--max));
  margin: 0 auto;
  padding: 64px 0 68px;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 48px;
  color: var(--muted);
  font-size: 13px;
}

.site-nav a {
  text-decoration: none;
}

.site-nav div {
  display: flex;
  gap: 18px;
}

.site-nav a[aria-current="page"] {
  color: var(--ink);
}

.site-mark {
  color: var(--ink);
  font-weight: 600;
}

.intro {
  max-width: 740px;
  padding-bottom: 34px;
  border-bottom: 1px solid var(--line);
}

.section-heading p,
time {
  margin: 0;
  color: var(--accent-2);
  font-family: var(--sans);
  font-size: 12px;
  font-weight: 600;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-family: var(--sans);
  font-weight: 600;
  line-height: 1.25;
}

h1 {
  font-size: clamp(38px, 7vw, 66px);
}

.lede {
  max-width: 690px;
  margin: 24px 0 0;
  color: #3c3934;
  font-family: var(--sans);
  font-size: 18px;
  line-height: 1.72;
}

.notes-section {
  padding: 26px 0 22px;
}

.about-section {
  padding: 26px 0 28px;
  border-bottom: 1px solid var(--line);
}

.about-kicker {
  margin: 0 0 10px;
  color: var(--accent-2);
  font-size: 12px;
  font-weight: 600;
}

.about-copy {
  max-width: 680px;
  margin: 0;
  color: #3f3f3f;
  font-size: 15px;
  line-height: 1.78;
}

.about-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
  margin-top: 24px;
}

.about-list h2 {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 600;
}

.about-list ul {
  display: grid;
  gap: 9px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.about-list li {
  font-size: 14px;
  line-height: 1.6;
}

.about-list li span {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: 12px;
}

.about-page {
  padding-top: 42px;
}

.about-hero {
  padding-bottom: 38px;
  border-bottom: 1px solid var(--line);
}

.about-hero h1 {
  font-size: clamp(34px, 6vw, 56px);
}

.about-hero > p:not(.about-kicker):not(.about-contact) {
  max-width: 680px;
  margin: 18px 0 0;
  color: #3f3f3f;
  font-size: 16px;
  line-height: 1.78;
}

.about-hero .about-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
  color: var(--muted);
  font-size: 13px;
}

.about-contact span {
  color: #c6cbd1;
}

.about-block {
  padding: 32px 0;
  border-bottom: 1px solid var(--line);
}

.about-block h2 {
  margin-bottom: 16px;
  color: var(--accent-2);
  font-size: 13px;
  font-weight: 600;
}

.about-items {
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.about-items li {
  max-width: 720px;
  font-size: 15px;
  line-height: 1.66;
}

.about-items li > a,
.about-items li > strong {
  display: inline;
  font-weight: 500;
}

.about-items li span {
  display: block;
  margin-top: 3px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.62;
}

.section-block {
  display: grid;
  grid-template-columns: 136px minmax(0, 1fr);
  gap: 36px;
  padding: 46px 0;
  border-top: 1px solid var(--line);
}

.section-heading {
  position: sticky;
  top: 76px;
  align-self: start;
}

.section-heading h2 {
  margin-top: 8px;
  font-size: 20px;
}

.note-list {
  display: grid;
  gap: 0;
}

.note-list article {
  padding: 18px 0;
  border-bottom: 1px solid rgba(215, 208, 196, 0.72);
}

.note-list h3 {
  margin-top: 8px;
  font-size: 17px;
  font-weight: 500;
  line-height: 1.55;
}

.note-list h3 a {
  text-decoration-thickness: 1px;
}

.note-list p {
  max-width: 620px;
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.note-list p,
.contact p {
  margin: 10px 0 0;
  color: var(--muted);
}

.quiet-list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.quiet-list li {
  padding-left: 18px;
  border-left: 3px solid rgba(49, 95, 101, 0.28);
}

.principles {
  display: grid;
  gap: 16px;
}

.principles p {
  margin: 0;
  padding: 18px 0;
  border-bottom: 1px solid rgba(215, 208, 196, 0.72);
  font-family: var(--sans);
  font-size: 17px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  width: min(100% - 48px, var(--max));
  margin: 0 auto;
  padding: 28px 0 42px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

.article-shell {
  width: min(100% - 44px, var(--article));
  margin: 0 auto;
  padding: 32px 0 70px;
}

.back-link {
  position: fixed;
  top: 22px;
  left: max(18px, calc((100vw - var(--article)) / 2 - 108px));
  z-index: 20;
  display: inline-flex;
  align-items: center;
  height: 32px;
  padding: 0 10px;
  border: 1px solid #e5e7eb;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: blur(10px);
  color: var(--muted);
  font-family: var(--sans);
  font-size: 14px;
  text-decoration: none;
}

.back-link:hover {
  border-color: #cfd4dc;
  background: #fff;
}

.article-header {
  margin-bottom: 36px;
}

.article-header h1 {
  max-width: 760px;
  font-size: clamp(30px, 5vw, 42px);
  line-height: 1.32;
}

.article-header time {
  display: block;
  margin-top: 16px;
  color: var(--muted);
  font-weight: 500;
}

.article-content {
  color: #262626;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.74;
  overflow-wrap: break-word;
}

.article-content h1,
.article-content h2,
.article-content h3,
.article-content h4 {
  margin: 2.1em 0 0.75em;
  font-family: var(--sans);
  font-weight: 600;
  line-height: 1.45;
}

.article-content h1 {
  font-size: 24px;
}

.article-content h2 {
  font-size: 21px;
}

.article-content h3 {
  font-size: 18px;
}

.article-content h4 {
  font-size: 16px;
}

.article-content p {
  margin: 0 0 0.92em;
}

.article-content a {
  color: var(--accent);
}

.article-content blockquote {
  margin: 1.6em 0;
  padding: 10px 16px;
  border-left: 4px solid #d9d9d9;
  background: #fafafa;
  color: #595959;
}

.article-content .callout {
  margin: 1.6em 0;
  padding: 14px 16px;
  border-left: 4px solid #d9d9d9;
  background: #fafafa;
  color: #3f3f46;
}

.article-content .callout-info {
  border-left-color: #167c80;
  background: #f0fdfa;
}

.article-content .callout-warning {
  border-left-color: #d97706;
  background: #fffbeb;
}

.article-content .callout-success {
  border-left-color: #16a34a;
  background: #f0fdf4;
}

.article-content .callout > :last-child {
  margin-bottom: 0;
}

.article-content ul,
.article-content ol {
  margin: 0 0 1.4em;
  padding-left: 1.45em;
}

.article-content li {
  margin: 0.28em 0;
}

.article-content figure {
  margin: 1.65em 0;
}

.article-content img,
.article-content video {
  display: block;
  width: auto;
  max-width: 100%;
  height: auto;
  margin: 0 auto;
  border: 0;
}

.article-content > img,
.article-content p > img {
  margin: 1.65em auto;
}

.article-content pre {
  overflow-x: auto;
  margin: 1.5em 0;
  padding: 16px;
  border: 1px solid #e5e7eb;
  background: var(--soft);
  font-size: 13px;
  line-height: 1.65;
}

.article-content code {
  font-family: Consolas, "SFMono-Regular", Menlo, monospace;
}

.article-content :not(pre) > code {
  padding: 0.12em 0.28em;
  border-radius: 3px;
  background: var(--soft);
  font-size: 0.88em;
}

.table-wrap {
  overflow-x: auto;
  max-width: 100%;
  margin: 1.8em 0;
  padding-bottom: 4px;
  -webkit-overflow-scrolling: touch;
}

.table-wrap table {
  width: max-content;
  min-width: 100%;
  border-collapse: collapse;
  table-layout: auto;
  font-size: 14px;
  line-height: 1.65;
}

.table-wrap td,
.table-wrap th {
  min-width: 120px;
  max-width: 520px;
  padding: 12px 14px;
  border: 1px solid #e5e7eb;
  background: #fff;
  text-align: left;
  vertical-align: top;
}

.table-wrap th {
  font-weight: 600;
  background: #fafafa;
}

.table-wrap img {
  max-width: none;
  margin: 0;
}

.table-wrap p {
  margin: 0 0 0.55em;
}

.table-wrap p:last-child {
  margin-bottom: 0;
}

.unsupported-card,
.source-note {
  color: var(--muted);
  font-family: var(--sans);
  font-size: 14px;
}

.source-note {
  margin-top: 56px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

@media (max-width: 720px) {
  body {
    font-size: 15px;
  }

  .page-shell {
    width: min(100% - 36px, var(--max));
    padding-top: 44px;
  }

  .lede {
    font-size: 17px;
  }

  .about-list {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .section-block {
    grid-template-columns: 1fr;
    gap: 18px;
    padding: 38px 0;
  }

  .section-heading {
    position: static;
  }

  .site-footer {
    flex-direction: column;
    width: min(100% - 36px, var(--max));
  }

  .article-shell {
    width: min(100% - 34px, var(--article));
    padding-top: 24px;
  }

  .back-link {
    top: 12px;
    left: 14px;
    height: 30px;
    font-size: 13px;
  }

  .article-content {
    font-size: 16px;
    line-height: 1.78;
  }
}