/* ==========================================================================
   云开 · 技术笔记 — 视觉系统
   极简暖调单色 + 编辑式排版
   ========================================================================== */

:root {
  --canvas: #F7F6F3;
  --canvas-deep: #F1EFEA;
  --surface: #FFFFFF;
  --surface-alt: #FBFBFA;

  --ink: #171716;
  --ink-2: #3D3D3A;
  --muted: #787774;
  --muted-2: #9A9893;

  --line: #E7E5E0;
  --line-strong: #D6D3CC;

  --pale-yellow: #FBF3DB;
  --yellow-ink: #8A5E00;
  --pale-blue: #E9F2F8;
  --blue-ink: #1F6C9F;
  --pale-red: #FBE9EA;
  --red-ink: #9F2F2D;
  --pale-green: #EDF3EC;
  --green-ink: #346538;

  --radius-sm: 4px;
  --radius: 10px;
  --radius-lg: 14px;

  --maxw: 1080px;
  --gutter: clamp(20px, 5vw, 48px);
  --section-y: clamp(72px, 10vw, 128px);

  --font-sans: "Inter var", -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC",
    system-ui, sans-serif;
  --font-serif: "Newsreader", "Iowan Old Style", "Source Serif 4", Georgia,
    "Songti SC", "Source Han Serif SC", "Noto Serif SC", "STSong", serif;
  --font-mono: "SF Mono", "JetBrains Mono", "IBM Plex Mono", ui-monospace,
    Menlo, Consolas, "Liberation Mono", monospace;

  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}

body {
  margin: 0;
  background: var(--canvas);
  color: var(--ink-2);
  font-family: var(--font-sans);
  font-size: 16.5px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection {
  background: #E8E4D9;
  color: var(--ink);
}

a {
  color: inherit;
  text-decoration: none;
}

img { max-width: 100%; display: block; }

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  color: var(--ink);
  font-weight: 500;
  letter-spacing: -0.025em;
  line-height: 1.14;
  margin: 0;
  text-wrap: balance;
}

p { margin: 0 0 1.15em; }
p:last-child { margin-bottom: 0; }

strong { color: var(--ink); font-weight: 600; }

hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 0;
}

/* ---------- 布局骨架 ---------- */

.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.wrap--narrow { max-width: 780px; }

.section {
  padding-block: var(--section-y);
  border-top: 1px solid var(--line);
}

.section--flush { border-top: 0; }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted-2);
  margin: 0 0 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--line-strong);
  display: inline-block;
}

/* ---------- 顶栏 ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(247, 246, 243, 0.82);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 64px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  font-family: var(--font-serif);
  font-size: 18px;
  letter-spacing: -0.015em;
  color: var(--ink);
}

.brand__mark {
  width: 26px;
  height: 26px;
  border: 1px solid var(--ink);
  border-radius: 6px;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0;
  color: var(--ink);
  background: var(--surface);
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted-2);
  text-transform: uppercase;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav__link {
  font-size: 14px;
  color: var(--muted);
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  transition: color 160ms var(--ease), background-color 160ms var(--ease);
}

.nav__link:hover { color: var(--ink); background: rgba(0, 0, 0, 0.035); }

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

.nav__cta {
  margin-left: 10px;
  font-size: 13.5px;
  padding: 8px 15px;
  border-radius: var(--radius-sm);
  background: var(--ink);
  color: #fff;
  transition: background-color 160ms var(--ease), transform 160ms var(--ease);
}

.nav__cta:hover { background: #333330; }
.nav__cta:active { transform: scale(0.98); }

/* 阅读进度 */
.progress {
  position: fixed;
  inset: 0 auto auto 0;
  height: 2px;
  width: 0;
  background: var(--ink);
  z-index: 60;
  transition: width 90ms linear;
}

/* ---------- 首页 Hero ---------- */

.hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(72px, 11vw, 132px);
}

.hero::before {
  content: "";
  position: absolute;
  inset: -20% -10% auto auto;
  width: 720px;
  height: 720px;
  background: radial-gradient(circle at center, rgba(196, 176, 128, 0.16), transparent 62%);
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(0, 0, 0, 0.028) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0, 0, 0, 0.028) 1px, transparent 1px);
  background-size: 88px 88px;
  mask-image: radial-gradient(ellipse 70% 60% at 70% 20%, #000 0%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 70% 20%, #000 0%, transparent 78%);
  pointer-events: none;
}

.hero__inner { position: relative; z-index: 1; }

.hero__title {
  font-size: clamp(2.5rem, 6.4vw, 4.15rem);
  letter-spacing: -0.035em;
  max-width: 15em;
}

.hero__title em {
  font-style: italic;
  color: var(--ink);
  position: relative;
  padding: 0 0.02em;
}

/* 标题里重点词下的细下划线，像批注，不发光 */
.hero__title em::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.1em;
  height: 1px;
  background: currentColor;
  opacity: 0.22;
}

.hero__lede {
  margin-top: 26px;
  max-width: 34em;
  font-size: 17px;
  color: var(--muted);
  line-height: 1.78;
}

.hero__meta {
  margin-top: 40px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14.5px;
  font-weight: 500;
  padding: 11px 20px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: background-color 180ms var(--ease), border-color 180ms var(--ease),
    color 180ms var(--ease), transform 140ms var(--ease);
  cursor: pointer;
}

.btn--solid { background: var(--ink); color: #fff; }
.btn--solid:hover { background: #333330; }
.btn--solid:active { transform: scale(0.985); }

.btn--ghost {
  background: var(--surface);
  border-color: var(--line-strong);
  color: var(--ink);
}
.btn--ghost:hover { border-color: var(--ink); background: #fff; }

.btn svg { width: 14px; height: 14px; }

.hero__facts {
  margin-top: 56px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.fact {
  background: var(--surface-alt);
  padding: 20px 22px;
}

.fact__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted-2);
  margin-bottom: 6px;
}

.fact__v { font-size: 14.5px; color: var(--ink); }

/* ---------- 通用小节头 ---------- */

.sec-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 40px;
}

.sec-head h2 {
  font-size: clamp(1.6rem, 2.9vw, 2.1rem);
}

.sec-head p {
  margin: 10px 0 0;
  font-size: 15px;
  color: var(--muted);
  max-width: 42em;
}

.sec-head__link {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap;
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 3px;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}
.sec-head__link:hover { color: var(--ink); border-color: var(--ink); }

/* ---------- 精选文章卡 ---------- */

.feature {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow 240ms var(--ease);
}

.feature:hover { box-shadow: 0 2px 14px rgba(0, 0, 0, 0.045); }

.feature__main {
  background: var(--surface);
  padding: clamp(26px, 3.4vw, 44px);
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.feature__title {
  font-size: clamp(1.55rem, 2.6vw, 2.15rem);
  letter-spacing: -0.03em;
}

.feature__desc {
  font-size: 15px;
  color: var(--muted);
  margin: 0;
  max-width: 34em;
}

.feature__side {
  background: var(--surface-alt);
  padding: clamp(26px, 3.4vw, 44px);
  display: flex;
  flex-direction: column;
  gap: 26px;
}

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

.mini {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 16px;
  align-items: baseline;
  padding: 15px 0;
  border-top: 1px solid var(--line);
  transition: color 160ms var(--ease);
}
.mini:first-child { border-top: 0; padding-top: 4px; }
.mini:hover .mini__t { color: var(--muted); }

.mini__t {
  font-family: var(--font-serif);
  font-size: 16.5px;
  color: var(--ink);
  letter-spacing: -0.015em;
  line-height: 1.35;
  transition: color 160ms var(--ease);
}

.mini__d {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--muted-2);
  white-space: nowrap;
}

.tag {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 4px 9px;
  border-radius: 999px;
  background: var(--pale-blue);
  color: var(--blue-ink);
  white-space: nowrap;
}

.tag--yellow { background: var(--pale-yellow); color: var(--yellow-ink); }
.tag--green { background: var(--pale-green); color: var(--green-ink); }
.tag--red { background: var(--pale-red); color: var(--red-ink); }
.tag--muted { background: #EFEDE7; color: var(--muted); }

.meta-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--muted-2);
  text-transform: uppercase;
}

.meta-row .dot { width: 3px; height: 3px; border-radius: 50%; background: var(--line-strong); }

/* ---------- 文章列表 ---------- */

.post-list { border-top: 1px solid var(--line); }

.post-row {
  display: grid;
  grid-template-columns: 92px 1fr auto;
  gap: clamp(16px, 3vw, 36px);
  align-items: baseline;
  padding: 26px 0;
  border-bottom: 1px solid var(--line);
  transition: background-color 200ms var(--ease);
}

.post-row:hover { background: rgba(255, 255, 255, 0.6); }

.post-row__date {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted-2);
  letter-spacing: 0.04em;
}

.post-row > span { display: block; min-width: 0; }

.post-row__t {
  display: block;
  font-family: var(--font-serif);
  font-size: clamp(1.1rem, 1.9vw, 1.32rem);
  color: var(--ink);
  letter-spacing: -0.02em;
  line-height: 1.3;
  transition: color 160ms var(--ease);
}
.post-row:hover .post-row__t { color: var(--muted); }

.post-row__d {
  display: block;
  margin: 7px 0 0;
  font-size: 14px;
  color: var(--muted);
  max-width: 46em;
}

.post-row__meta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.post-row--soon { opacity: 0.62; }

/* ---------- 关于 ---------- */

.about {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: clamp(28px, 5vw, 72px);
  align-items: start;
}

.about__lead {
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 2.3vw, 1.7rem);
  line-height: 1.4;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.about__body p { color: var(--ink-2); font-size: 15.5px; }

.spec {
  margin-top: 28px;
  border-top: 1px solid var(--line);
}

.spec__row {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
}

.spec__k { color: var(--muted-2); font-family: var(--font-mono); font-size: 11.5px; letter-spacing: 0.08em; text-transform: uppercase; padding-top: 3px; }
.spec__v { color: var(--ink); }

/* ---------- 订阅 / 页脚 ---------- */

.subscribe {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 32px 36px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
}

.subscribe h3 { font-size: 1.35rem; }
.subscribe p { margin: 8px 0 0; font-size: 14px; color: var(--muted); }

.footer {
  border-top: 1px solid var(--line);
  padding-block: 48px 56px;
  font-size: 13.5px;
  color: var(--muted);
}

.footer__inner {
  display: flex;
  flex-wrap: wrap;
  gap: 20px 40px;
  justify-content: space-between;
  align-items: flex-start;
}

.footer__links { display: flex; flex-wrap: wrap; gap: 18px; }
.footer__links a { transition: color 160ms var(--ease); }
.footer__links a:hover { color: var(--ink); }

.footer__sig {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--muted-2);
  text-transform: uppercase;
}

/* ---------- 文章页 ---------- */

.article-head {
  padding-block: clamp(56px, 8vw, 92px) clamp(32px, 5vw, 52px);
  border-bottom: 1px solid var(--line);
}

.article-head__inner { max-width: 780px; }

.article-title {
  font-size: clamp(2rem, 4.8vw, 3.1rem);
  letter-spacing: -0.035em;
  margin-top: 22px;
}

.article-lede {
  margin-top: 24px;
  font-size: 17.5px;
  line-height: 1.72;
  color: var(--muted);
  max-width: 36em;
}

.article-meta {
  margin-top: 30px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 16px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.article-meta .sep { color: var(--line-strong); }

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 208px;
  gap: clamp(32px, 6vw, 84px);
  align-items: start;
  padding-block: clamp(40px, 6vw, 64px) var(--section-y);
}

.article-body { max-width: 720px; font-size: 16.5px; line-height: 1.82; }

.article-body > * + * { margin-top: 1.1em; }

.article-body h2 {
  font-size: clamp(1.45rem, 2.6vw, 1.85rem);
  margin-top: 2.1em;
  margin-bottom: 0.7em;
  scroll-margin-top: 96px;
}

.article-body h3 {
  font-size: 1.16rem;
  letter-spacing: -0.015em;
  margin-top: 1.9em;
  margin-bottom: 0.55em;
  scroll-margin-top: 96px;
}

.article-body p { color: var(--ink-2); }

.article-body ul,
.article-body ol { padding-left: 1.25em; margin: 0 0 1.15em; }
.article-body li { margin-bottom: 0.5em; }
.article-body li::marker { color: var(--muted-2); }

.article-body a:not(.btn) {
  color: var(--ink);
  border-bottom: 1px solid var(--line-strong);
  transition: border-color 160ms var(--ease);
}
.article-body a:not(.btn):hover { border-color: var(--ink); }

.article-body code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: #F1EFE9;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1px 5px;
  color: var(--ink);
  white-space: nowrap;
}

.article-body blockquote {
  margin: 1.6em 0;
  padding: 2px 0 2px 22px;
  border-left: 2px solid var(--line-strong);
  color: var(--muted);
  font-family: var(--font-serif);
  font-size: 1.08rem;
}

/* 目录 */
.toc {
  position: sticky;
  top: 96px;
  font-size: 13px;
}

.toc__label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted-2);
  margin-bottom: 14px;
}

.toc__list { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; border-left: 1px solid var(--line); }

.toc__list a {
  display: block;
  padding: 6px 0 6px 14px;
  margin-left: -1px;
  border-left: 1px solid transparent;
  color: var(--muted);
  line-height: 1.45;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.toc__list a:hover { color: var(--ink); }

.toc__list a.is-active {
  color: var(--ink);
  border-left-color: var(--ink);
}

/* 代码块 */
.code {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #FCFBF9;
  margin: 1.5em 0;
}

.code__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 8px 12px 8px 16px;
  border-bottom: 1px solid var(--line);
  background: #F7F6F3;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.code__copy {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 4px;
  padding: 3px 8px;
  cursor: pointer;
  transition: color 160ms var(--ease), border-color 160ms var(--ease), background-color 160ms var(--ease);
}

.code__copy:hover { color: var(--ink); border-color: var(--line-strong); background: #fff; }
.code__copy.is-done { color: var(--green-ink); border-color: var(--pale-green); background: var(--pale-green); }

.code pre {
  margin: 0;
  padding: 16px 18px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.75;
  color: #2C2C29;
  background: transparent;
}

.code pre code {
  background: none;
  border: 0;
  padding: 0;
  white-space: pre;
  font-size: inherit;
  color: inherit;
}

.cm { color: #9A9893; }
.cm-flag { color: var(--blue-ink); }

/* 提示块 */
.note {
  display: grid;
  grid-template-columns: 20px 1fr;
  gap: 14px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-alt);
  margin: 1.6em 0;
  font-size: 14.5px;
  line-height: 1.72;
}

.note__icon { padding-top: 2px; color: var(--muted); }
.note__icon svg { width: 16px; height: 16px; display: block; }
.note__body p { margin: 0; color: var(--ink-2); }
.note__body p + p { margin-top: 0.6em; }

.note--warn { background: var(--pale-red); border-color: #F2DCDD; }
.note--warn .note__icon { color: var(--red-ink); }
.note--warn .note__body p { color: #7A2B29; }

.note--tip { background: var(--pale-yellow); border-color: #F2E7C7; }
.note--tip .note__icon { color: var(--yellow-ink); }
.note--tip .note__body p { color: #6E4C00; }

/* 步骤 */
.steps { display: grid; gap: 0; margin: 1.8em 0; border-top: 1px solid var(--line); }

.step {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 18px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.step__n {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--muted-2);
  border: 1px solid var(--line);
  border-radius: 999px;
  width: 24px;
  height: 24px;
  display: grid;
  place-items: center;
  margin-top: 3px;
  background: var(--surface);
}

.step h4 { font-family: var(--font-sans); font-size: 15.5px; font-weight: 600; letter-spacing: -0.01em; margin: 0 0 6px; color: var(--ink); }
.step p { margin: 0; font-size: 15px; color: var(--muted); }

/* 插件卡 */
.plugins { display: grid; gap: 12px; margin: 1.8em 0; }

.plugin {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 20px 22px;
  transition: box-shadow 220ms var(--ease), border-color 220ms var(--ease);
}

.plugin:hover { box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04); border-color: var(--line-strong); }

.plugin__top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 8px;
}

.plugin__name {
  font-family: var(--font-mono);
  font-size: 13.5px;
  color: var(--ink);
  letter-spacing: 0;
}

.plugin__desc { margin: 0; font-size: 14.5px; color: var(--muted); line-height: 1.68; }

.plugin__cmd {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-2);
  background: #F7F6F3;
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 7px 10px;
  overflow-x: auto;
  white-space: nowrap;
}

/* 表格 */
.table-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 1.6em 0;
  background: var(--surface);
}

table { width: 100%; min-width: 560px; border-collapse: collapse; font-size: 14px; background: var(--surface); }

table td:first-child { width: 30%; }
table th:first-child { width: 30%; }

th, td {
  text-align: left;
  padding: 11px 16px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

th {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted-2);
  font-weight: 500;
  background: var(--surface-alt);
}

tr:last-child td { border-bottom: 0; }

td code, th code { font-size: 12px; }

/* 键盘键 */
kbd {
  font-family: var(--font-mono);
  font-size: 11.5px;
  border: 1px solid var(--line-strong);
  border-bottom-width: 2px;
  border-radius: 4px;
  background: #F7F6F3;
  padding: 1px 6px;
  color: var(--ink-2);
  white-space: nowrap;
}

/* FAQ */
.faq { margin: 1.6em 0 0; border-top: 1px solid var(--line); }

.faq details { border-bottom: 1px solid var(--line); }

.faq summary {
  list-style: none;
  cursor: pointer;
  padding: 17px 32px 17px 0;
  position: relative;
  font-size: 15.5px;
  color: var(--ink);
  font-weight: 500;
  letter-spacing: -0.005em;
}

.faq summary::-webkit-details-marker { display: none; }

.faq summary::after {
  content: "+";
  position: absolute;
  right: 2px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--muted-2);
  line-height: 1;
}

.faq details[open] summary::after { content: "−"; color: var(--ink); }

.faq .faq__a {
  padding: 0 24px 18px 0;
  font-size: 14.5px;
  color: var(--muted);
  line-height: 1.75;
}

.faq .faq__a p { margin: 0 0 0.7em; }
.faq .faq__a p:last-child { margin: 0; }

/* 文章尾 */
.article-end {
  margin-top: 56px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}

.article-end__row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: space-between;
  align-items: center;
}

.author {
  display: flex;
  gap: 16px;
  align-items: center;
}

.author__avatar {
  width: 42px;
  height: 42px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: var(--pale-yellow);
  display: grid;
  place-items: center;
  font-family: var(--font-serif);
  font-size: 17px;
  color: var(--yellow-ink);
  flex: none;
}

.author__name { font-size: 14.5px; color: var(--ink); }
.author__bio { font-size: 12.5px; color: var(--muted); font-family: var(--font-mono); letter-spacing: 0.02em; }

/* 动效 */
.reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 620ms var(--ease), transform 620ms var(--ease);
  will-change: opacity, transform;
}

.reveal.is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; }
}

/* ---------- 响应式 ---------- */

@media (max-width: 960px) {
  .article-layout { grid-template-columns: 1fr; }
  .toc { display: none; }
  .feature { grid-template-columns: 1fr; }
  .about { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  body { font-size: 16px; }
  .nav__links { gap: 0; }
  .nav__link { padding: 7px 9px; font-size: 13.5px; }
  .nav__cta { display: none; }
  .brand__sub { display: none; }
  .post-row { grid-template-columns: 1fr; gap: 8px; }
  .post-row__meta { justify-content: flex-start; }
  .hero__meta { gap: 12px; }
  .hero__facts { grid-template-columns: 1fr 1fr; }
  .sec-head { display: block; }
  .sec-head__link { display: inline-block; margin-top: 14px; }
  .subscribe { padding: 24px; }
  .article-body { font-size: 16px; }
}

@media (max-width: 430px) {
  .hero__facts { grid-template-columns: 1fr; }
  .about__lead { font-size: 1.25rem; }
}

/* ---------- 开场：上滑入场 ---------- */

body.is-locked { overflow: hidden; }

.curtain {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: clamp(32px, 8vh, 96px) var(--gutter);
  background: var(--canvas);
  background-image:
    linear-gradient(to right, rgba(23, 23, 22, 0.028) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(23, 23, 22, 0.028) 1px, transparent 1px);
  background-size: 72px 72px;
  border-bottom: 1px solid var(--line);
  touch-action: none;
  overscroll-behavior: contain;
  user-select: none;
  -webkit-user-select: none;
  cursor: grab;
  will-change: transform;
}

.curtain:active { cursor: grabbing; }

.curtain__inner {
  max-width: 620px;
  text-align: center;
  margin-bottom: clamp(56px, 12vh, 120px);
}

.curtain__eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted-2);
  margin: 0 0 clamp(20px, 3vh, 30px);
}

.curtain__title {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(2rem, 5.6vw, 3.35rem);
  line-height: 1.16;
  letter-spacing: -0.03em;
  color: var(--ink);
  margin: 0;
}

.curtain__title em {
  font-style: italic;
  position: relative;
  white-space: nowrap;
}

.curtain__title em::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.1em;
  height: 1px;
  background: currentColor;
  opacity: 0.24;
}

.curtain__sub {
  margin: clamp(18px, 3vh, 28px) auto 0;
  max-width: 24em;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--muted);
}

.curtain__go {
  position: absolute;
  left: 50%;
  bottom: clamp(40px, 9vh, 88px);
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 10px 18px 0;
  background: none;
  border: 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--muted);
  cursor: pointer;
  transition: color 200ms var(--ease);
}

.curtain__go:hover { color: var(--ink); }

.curtain__go svg {
  width: 15px;
  height: 15px;
  animation: curtainHint 2.4s var(--ease) infinite;
}

.curtain__go span { padding-left: 0.16em; }

@keyframes curtainHint {
  0%, 70%, 100% { transform: translateY(0); opacity: 0.75; }
  85% { transform: translateY(-6px); opacity: 1; }
}

.curtain__meter {
  position: absolute;
  left: 50%;
  bottom: clamp(26px, 6vh, 58px);
  transform: translateX(-50%);
  width: 132px;
  height: 2px;
  background: var(--line-strong);
  overflow: hidden;
  opacity: 0;
  transition: opacity 200ms var(--ease);
}

.curtain.is-dragging .curtain__meter { opacity: 1; }

.curtain__meter i {
  display: block;
  width: 0;
  height: 100%;
  background: var(--ink);
}

.curtain.is-dragging { transition: none; }

html.is-curtain-drag,
html.is-curtain-drag * {
  -webkit-user-select: none;
  user-select: none;
  cursor: grabbing;
}

.curtain.is-up {
  transform: translateY(-101%);
  opacity: 0;
  pointer-events: none;
  transition: transform 880ms var(--ease), opacity 880ms var(--ease);
}

@media (prefers-reduced-motion: reduce) {
  .curtain { display: none; }
  body.is-locked { overflow: auto; }
  .curtain__go svg { animation: none; }
  .curtain.is-up { transition: none; }
}