/* SOLO PRIMUS · 凌霄
   Typography follows jamesclear.com: a classic serif for reading (Minion Pro there, Crimson Pro here)
   and a geometric sans for headings and interface (Europa there, Figtree here).
   Chinese pages pair 思源宋体 (Noto Serif SC) for reading with the system 黑体 for headings. */

:root {
  --paper: #fdfcf9;
  --band: #f5f3ee;
  --card: #ffffff;
  --ink: #171715;
  --ink-2: #3a3935;
  --muted: #6b6962;
  --line: #e7e3db;
  --line-2: #d4cec3;
  --accent: #a4461d;
  --accent-ink: #8c3915;
  --accent-soft: #f6e6d8;
  --accent-line: #e4bfa1;
  --btn: #a4461d;
  --btn-hover: #8c3915;
  --btn-ink: #fffaf5;
  --seg-1: #d9d2c6;
  --seg-2: #a4461d;
  --seg-3: #8f897e;
  --seg-4: #3f3d38;
  --seg-hand: #cfc8bb;
  --art-filter: none;

  --sans: "Figtree", "Avenir Next", "Segoe UI", system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --serif: "Crimson Pro", "Iowan Old Style", "Palatino Linotype", Georgia, "Songti SC", "STSong", serif;
  --brand-font: "Figtree", "Avenir Next", "Segoe UI", system-ui, sans-serif;

  --wrap: 1120px;
  --measure: 680px;
  --gutter: clamp(16px, 4vw, 32px);
  color-scheme: light;
}

:root[data-theme="dark"] {
  --paper: #151615;
  --band: #1b1d1c;
  --card: #202322;
  --ink: #eeede8;
  --ink-2: #cfcdc6;
  --muted: #a19f98;
  --line: #2c2f2d;
  --line-2: #3d413e;
  --accent: #e8a06d;
  --accent-ink: #f0b58b;
  --accent-soft: #3a2a1f;
  --accent-line: #6e4c34;
  --btn: #e8a06d;
  --btn-hover: #f0b58b;
  --btn-ink: #1b140f;
  --seg-1: #4a4e4b;
  --seg-2: #e8a06d;
  --seg-3: #8a8e8a;
  --seg-4: #d9d7d0;
  --seg-hand: #5a5f5b;
  --art-filter: brightness(.86) saturate(.9);
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --paper: #151615; --band: #1b1d1c; --card: #202322; --ink: #eeede8; --ink-2: #cfcdc6; --muted: #a19f98;
    --line: #2c2f2d; --line-2: #3d413e; --accent: #e8a06d; --accent-ink: #f0b58b; --accent-soft: #3a2a1f;
    --accent-line: #6e4c34; --btn: #e8a06d; --btn-hover: #f0b58b; --btn-ink: #1b140f; --seg-1: #4a4e4b;
    --seg-2: #e8a06d; --seg-3: #8a8e8a; --seg-4: #d9d7d0; --seg-hand: #5a5f5b; --art-filter: brightness(.86) saturate(.9);
    color-scheme: dark;
  }
}

html:lang(zh-CN) {
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC", "Figtree", system-ui, sans-serif;
  --serif: "Noto Serif SC", "Songti SC", "Source Han Serif SC", "Noto Serif CJK SC", "STSong", serif;
}

/* ---------------------------------------------------------------- base */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.25rem;
  line-height: 1.6;
  font-kerning: normal;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-autospace: normal;
}
html:lang(zh-CN) body { font-size: 1.125rem; line-height: 1.9; }
img, svg { display: block; max-width: 100%; }
h1, h2, h3, h4 { font-family: var(--sans); font-weight: 700; color: var(--ink); margin: 0; text-wrap: balance; }
/* Chinese headings break at punctuation, not inside a phrase. */
html:lang(zh-CN) :is(h1, h2, h3, h4) { word-break: keep-all; overflow-wrap: anywhere; }
p { margin: 0; text-wrap: pretty; }
a {
  color: inherit;
  text-decoration-line: underline;
  text-decoration-color: var(--accent-line);
  text-decoration-thickness: 2px;
  text-underline-offset: .22em;
  transition: color .15s ease, text-decoration-color .15s ease;
}
a:hover { color: var(--accent-ink); text-decoration-color: currentColor; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }

.wrap { width: 100%; max-width: calc(var(--wrap) + 2 * var(--gutter)); margin-inline: auto; padding-inline: var(--gutter); }

.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 100;
  padding: 10px 16px; border-radius: 4px;
  background: var(--ink); color: var(--paper);
  font: 600 15px/1 var(--sans); text-decoration: none;
}
.skip-link:focus { top: 12px; }

.eyebrow {
  font-family: var(--sans); font-size: 13px; font-weight: 700; line-height: 1.4;
  letter-spacing: .14em; text-transform: uppercase; color: var(--accent-ink);
  margin: 0 0 16px;
}
html:lang(zh-CN) .eyebrow { font-size: 14px; letter-spacing: .12em; font-weight: 600; }

.lead { font-size: clamp(1.25rem, 1.1rem + .5vw, 1.45rem); line-height: 1.55; color: var(--ink-2); max-width: 34em; }
html:lang(zh-CN) .lead { font-size: clamp(1.08rem, 1rem + .35vw, 1.22rem); line-height: 1.9; max-width: 36em; }

.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 15px 22px; border: 1px solid transparent; border-radius: 4px;
  background: var(--btn); color: var(--btn-ink);
  font: 700 16px/1.1 var(--sans); text-decoration: none; white-space: nowrap;
  transition: background-color .15s ease, border-color .15s ease, color .15s ease;
}
.btn:hover { background: var(--btn-hover); color: var(--btn-ink); }
.btn svg { width: 16px; height: 16px; flex: none; }
.btn-quiet { background: transparent; color: var(--ink); border-color: var(--line-2); }
.btn-quiet:hover { background: var(--card); color: var(--ink); border-color: var(--ink-2); }
.text-link { font: 600 16px/1.4 var(--sans); color: var(--ink); text-decoration-color: var(--accent-line); }
.text-link:hover { color: var(--accent-ink); }

/* ---------------------------------------------------------------- header */
.site-header { position: relative; z-index: 20; background: var(--paper); border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; gap: 28px; min-height: 76px; }
.brand { display: inline-flex; align-items: center; gap: 11px; margin-right: auto; color: var(--ink); text-decoration: none; }
.brand:hover { color: var(--ink); }
.brand-mark { width: 30px; height: 24px; flex: none; color: var(--accent); }
.brand-name { font: 700 15px/1 var(--brand-font); letter-spacing: .24em; text-transform: uppercase; }
.brand-cn { padding-left: 11px; border-left: 1px solid var(--line-2); font: 600 15px/1 var(--sans); letter-spacing: .12em; color: var(--ink-2); }

.site-nav { display: flex; align-items: center; gap: 30px; font: 500 15.5px/1.2 var(--sans); }
.site-nav a { padding-block: 8px; color: var(--ink-2); text-decoration: none; border-bottom: 2px solid transparent; }
.site-nav a:hover { color: var(--ink); }
.site-nav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--accent); }
.site-nav .lang-link { padding: 6px 12px; border: 1px solid var(--line-2); border-radius: 999px; font-size: 14px; }
.site-nav .lang-link:hover { border-color: var(--ink-2); }

.header-tools { display: flex; align-items: center; gap: 4px; margin-right: -8px; }
.icon-btn {
  display: grid; place-items: center; width: 42px; height: 42px; padding: 0;
  border: 0; border-radius: 8px; background: transparent; color: var(--ink-2); cursor: pointer;
}
.icon-btn:hover { background: var(--band); color: var(--ink); }
.icon-btn svg { width: 20px; height: 20px; }
.theme-toggle .i-moon { display: none; }
:root[data-theme="dark"] .theme-toggle .i-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .i-moon { display: block; }
.nav-toggle { display: none; }
.nav-toggle span { display: block; width: 20px; height: 2px; margin: 3px 0; background: currentColor; transition: transform .2s ease; }
.nav-toggle[aria-expanded="true"] span:first-child { transform: translateY(4px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:last-child { transform: translateY(-4px) rotate(-45deg); }

@media (max-width: 880px) {
  .header-inner { min-height: 68px; gap: 12px; }
  .nav-toggle { display: grid; }
  .site-nav {
    position: absolute; top: 100%; left: 0; right: 0;
    display: none; flex-direction: column; align-items: stretch; gap: 0;
    padding: 4px var(--gutter) 20px; background: var(--paper); border-bottom: 1px solid var(--line);
    box-shadow: 0 16px 32px rgba(0, 0, 0, .06);
  }
  .site-nav.is-open { display: flex; }
  .site-nav a { padding: 14px 0; border-bottom: 1px solid var(--line); font-size: 17px; }
  .site-nav a[aria-current="page"] { border-bottom-color: var(--line); color: var(--accent-ink); }
  .site-nav .lang-link { align-self: flex-start; margin-top: 16px; padding: 8px 14px; border: 1px solid var(--line-2); }
}
@media (max-width: 400px) {
  .brand-name { letter-spacing: .18em; font-size: 14px; }
  .brand-cn { padding-left: 9px; font-size: 14px; }
}

/* ---------------------------------------------------------------- sections */
.section { padding-block: clamp(56px, 8vw, 104px); }
.band { background: var(--band); }
.section-head { max-width: 760px; margin-bottom: clamp(32px, 4vw, 52px); }
.section-head h2 { font-size: clamp(1.9rem, 1.35rem + 1.9vw, 2.75rem); line-height: 1.12; letter-spacing: -.015em; margin-bottom: 16px; }
html:lang(zh-CN) .section-head h2 { font-size: clamp(1.65rem, 1.3rem + 1.4vw, 2.3rem); line-height: 1.35; letter-spacing: .02em; }
.section-intro { color: var(--ink-2); max-width: 40em; }
.section-more { margin-top: 32px; }

/* ---------------------------------------------------------------- hero */
.hero {
  display: grid; grid-template-columns: minmax(0, 1.3fr) minmax(0, .7fr);
  gap: 0 clamp(24px, 5vw, 64px); align-items: center;
  padding-block: clamp(44px, 7vw, 88px) clamp(48px, 6vw, 72px);
}
.hero h1 { font-size: clamp(2.4rem, 1.5rem + 3vw, 3.4rem); line-height: 1.08; letter-spacing: -.025em; margin-bottom: 24px; }
.hero h1 span { display: block; }
html:lang(zh-CN) .hero h1 { font-size: clamp(2.05rem, 1.4rem + 2.6vw, 3.2rem); line-height: 1.3; letter-spacing: .01em; }
.hero .lead { margin-bottom: 32px; }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 14px 26px; }

/* Credentials, readable at a glance. */
.facts {
  grid-column: 1 / -1; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: clamp(40px, 5vw, 64px) 0 0; border-top: 1px solid var(--line-2); border-bottom: 1px solid var(--line-2);
}
.facts div { padding: 18px 20px 18px 0; }
.facts div + div { padding-left: 20px; border-left: 1px solid var(--line); }
.facts dt { margin-bottom: 6px; font: 700 11.5px/1.3 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
.facts dd { margin: 0; font: 600 17px/1.35 var(--sans); color: var(--ink); }
html:lang(zh-CN) .facts dt { font-size: 13px; letter-spacing: .1em; }
html:lang(zh-CN) .facts dd { font-size: 17px; }

.hero-art { position: relative; min-width: 0; }
.hero-art-inner { position: relative; width: 118%; margin-inline: -9%; isolation: isolate; }
.hero-art img { width: 100%; height: auto; filter: var(--art-filter); }
/* A single studio highlight crosses the sculpture once when the page opens. */
.hero-art-inner::after {
  content: ""; position: absolute; inset: 0; pointer-events: none; opacity: 0;
  background: linear-gradient(110deg, transparent 39%, #fff9e890 48%, #fffdf9c0 50%, transparent 60%);
  background-size: 300% 100%; background-position: 140% 0;
  -webkit-mask: url("../images/mountain-sculpture.webp") center / contain no-repeat;
  mask: url("../images/mountain-sculpture.webp") center / contain no-repeat;
  mix-blend-mode: screen;
}
/* Plays once on load (about three seconds), so the page needs no pause control. */
@media (prefers-reduced-motion: no-preference) {
  .hero-art-inner { animation: art-rise 1.6s cubic-bezier(.2, .7, .2, 1) both; }
  .hero-art-inner::after { animation: art-sheen 2.2s .7s ease-out both; }
}
@keyframes art-rise { from { transform: translateY(22px) scale(.97); } to { transform: none; } }
@keyframes art-sheen {
  0% { opacity: .3; background-position: 140% 0; }
  85% { opacity: .3; }
  100% { opacity: 0; background-position: -45% 0; }
}

@media (max-width: 880px) {
  .hero { grid-template-columns: 1fr; }
  .hero-art { max-width: 420px; width: 100%; justify-self: center; }
  .hero-art-inner { width: 112%; margin-inline: -6%; }
}
@media (max-width: 880px) {
  .facts { grid-row: 2; margin-top: 36px; }
  .hero-art { grid-row: 3; margin-top: 24px; }
}
@media (max-width: 640px) {
  .facts { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .facts div { padding-block: 14px; }
  .facts div:nth-child(3) { padding-left: 0; border-left: 0; }
  .facts div:nth-child(n + 3) { border-top: 1px solid var(--line); }
  .facts dd { font-size: 16px; }
}

/* ---------------------------------------------------------------- levers */
.lever-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(20px, 3vw, 36px); }
.lever { display: flex; flex-direction: column; padding-top: 22px; border-top: 2px solid var(--ink); }
.lever-kicker { margin-bottom: 12px; font: 700 12.5px/1.4 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--accent-ink); }
html:lang(zh-CN) .lever-kicker { font-size: 14px; letter-spacing: .1em; }
.lever h3 { font-size: clamp(1.3rem, 1.15rem + .5vw, 1.5rem); line-height: 1.25; margin-bottom: 10px; }
html:lang(zh-CN) .lever h3 { line-height: 1.45; }
.lever-text { font-size: 1.125rem; line-height: 1.55; color: var(--ink-2); margin-bottom: 22px; }
html:lang(zh-CN) .lever-text { font-size: 1.02rem; line-height: 1.85; }
.lever .text-link { margin-top: auto; padding-top: 20px; align-self: flex-start; justify-self: start; }
@media (max-width: 960px) { .lever-grid { grid-template-columns: 1fr; gap: 44px; } }
/* Line up kicker, title, text, diagram, and link across the three columns. */
@supports (grid-template-rows: subgrid) {
  @media (min-width: 961px) {
    .lever-grid { row-gap: 0; }
    .lever { display: grid; grid-row: span 5; grid-template-rows: subgrid; align-content: start; }
  }
}

/* diagrams */
.diagram {
  display: flex; flex-direction: column; flex: 1; margin: 0;
  padding: 18px 18px 16px; background: var(--card); border: 1px solid var(--line); border-radius: 6px;
  font-family: var(--sans); color: var(--ink);
}
.diagram-label { margin-bottom: 14px; font: 700 11.5px/1.3 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
html:lang(zh-CN) .diagram-label { font-size: 13px; letter-spacing: .1em; }
.diagram-body { margin-block: auto; }
.diagram-caption { padding-top: 14px; font: 400 13px/1.5 var(--sans); color: var(--muted); }

.thesis-rows { list-style: none; margin: 0; padding: 0; counter-reset: thesis; border-top: 1px solid var(--line); }
.thesis-rows li {
  counter-increment: thesis;
  display: grid; grid-template-columns: 24px minmax(0, 1fr); column-gap: 8px;
  padding: 9px 0; border-bottom: 1px dashed var(--line-2);
}
.thesis-rows li::before { content: counter(thesis); grid-row: span 2; font: 700 13px/1.5 var(--sans); color: var(--accent); }
.thesis-rows b { font-size: 14px; line-height: 1.4; }
.thesis-rows span { font-size: 13.5px; line-height: 1.45; color: var(--muted); }

.bars { display: grid; gap: 12px; }
.bar-row { display: grid; grid-template-columns: 64px minmax(0, 1fr) 54px; align-items: center; gap: 10px; font-size: 13.5px; }
html:lang(zh-CN) .bar-row { grid-template-columns: 58px minmax(0, 1fr) 58px; }
.bar-name { color: var(--ink-2); font-weight: 600; }
.bar-track { display: flex; height: 26px; }
.seg { display: block; height: 100%; width: var(--w); }
.seg + .seg { box-shadow: inset 2px 0 0 var(--card); }
.seg-1 { background: var(--seg-1); }
.seg-2 { background: var(--seg-2); }
.seg-3 { background: var(--seg-3); }
.seg-4 { background: var(--seg-4); }
.seg-hand { background: var(--seg-hand); }
.bar-total { text-align: right; font-weight: 700; font-variant-numeric: tabular-nums; white-space: nowrap; }
.legend { list-style: none; display: flex; flex-wrap: wrap; gap: 6px 14px; margin: 14px 0 0; padding: 0; font-size: 12.5px; color: var(--muted); font-variant-numeric: tabular-nums; }
.legend li { display: inline-flex; align-items: center; gap: 6px; }
.legend i { display: inline-block; width: 10px; height: 10px; border-radius: 2px; }

.diagram-loop svg { width: 100%; max-width: 300px; height: auto; margin-inline: auto; overflow: visible; }
.loop-arcs path { stroke: var(--line-2); stroke-width: 1.6; }
.loop-head { fill: var(--accent); }
.loop-nodes circle { fill: var(--accent); }
.loop-labels text { fill: var(--ink); font: 600 13.5px var(--sans); }
.loop-center { fill: var(--muted); font: 600 11.5px var(--sans); letter-spacing: .14em; text-transform: uppercase; }
html:lang(zh-CN) .loop-center { letter-spacing: .1em; font-size: 12.5px; }

/* ---------------------------------------------------------------- essay lists */
.essay-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--line-2); }
.essay-row { display: grid; grid-template-columns: 190px minmax(0, 1fr); gap: 8px 36px; padding: 26px 0 28px; border-bottom: 1px solid var(--line); }
.essay-meta { display: flex; flex-direction: column; gap: 6px; padding-top: 5px; font: 400 13.5px/1.4 var(--sans); color: var(--muted); }
.topic-tag { font: 700 12px/1.4 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--accent-ink); text-decoration: none; }
html:lang(zh-CN) .topic-tag { font-size: 13px; letter-spacing: .08em; }
.topic-tag:hover { color: var(--accent); }
.essay-main h3, .essay-main h4 { font-size: clamp(1.25rem, 1.15rem + .4vw, 1.45rem); line-height: 1.3; margin-bottom: 8px; }
html:lang(zh-CN) .essay-main h3, html:lang(zh-CN) .essay-main h4 { line-height: 1.5; }
.essay-main h3 a, .essay-main h4 a { text-decoration: none; }
.essay-main h3 a:hover, .essay-main h4 a:hover { color: var(--accent-ink); }
.essay-main p { font-size: 1.125rem; line-height: 1.55; color: var(--ink-2); max-width: 40em; }
html:lang(zh-CN) .essay-main p { font-size: 1.02rem; line-height: 1.85; }
.essay-main .essay-orig { margin-top: 6px; font: 400 14px/1.5 var(--sans); color: var(--muted); }
.badge {
  display: inline-block; margin-left: 6px; padding: 2px 8px; vertical-align: 3px;
  border: 1px solid var(--line-2); border-radius: 999px;
  font: 600 12px/1.3 "PingFang SC", "Microsoft YaHei", var(--sans); letter-spacing: 0; color: var(--muted);
}
.also { margin-top: 56px; }
.list-subhead { font-size: 1.35rem; margin-bottom: 6px; }
.list-note { margin-bottom: 18px; font: 400 15px/1.5 var(--sans); color: var(--muted); }
@media (max-width: 720px) {
  .essay-row { grid-template-columns: 1fr; padding: 22px 0 24px; }
  .essay-meta { flex-direction: row; flex-wrap: wrap; align-items: baseline; gap: 4px 14px; padding-top: 0; }
}

/* ---------------------------------------------------------------- intro band */
.intro-grid { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr); gap: clamp(36px, 7vw, 104px); align-items: start; }
.intro-copy h2 { font-size: clamp(1.8rem, 1.4rem + 1.3vw, 2.4rem); line-height: 1.15; letter-spacing: -.01em; margin-bottom: 20px; }
html:lang(zh-CN) .intro-copy h2 { line-height: 1.4; letter-spacing: .02em; }
.intro-copy p { margin-bottom: 1em; color: var(--ink-2); max-width: 34em; }
.intro-copy .text-link { display: inline-block; margin-top: 6px; }
.intro-side h3 { margin-bottom: 14px; font: 700 12.5px/1.4 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
html:lang(zh-CN) .intro-side h3 { font-size: 14px; letter-spacing: .1em; }
.principles { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--line-2); }
.principles li { display: flex; gap: 14px; padding: 15px 0; border-bottom: 1px solid var(--line); font: 600 17px/1.45 var(--sans); color: var(--ink); }
.principles li::before { content: ""; flex: none; width: 8px; height: 8px; margin-top: .5em; background: var(--accent); }
@media (max-width: 820px) { .intro-grid { grid-template-columns: 1fr; } }

/* ---------------------------------------------------------------- follow & footer */
.follow { background: var(--accent-soft); padding-block: clamp(48px, 6vw, 72px); }
.follow-inner { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 28px 56px; align-items: center; }
.follow h2 { font-size: clamp(1.6rem, 1.3rem + 1vw, 2.15rem); line-height: 1.2; margin-bottom: 10px; }
html:lang(zh-CN) .follow h2 { line-height: 1.45; }
.follow p:not(.eyebrow) { color: var(--ink-2); max-width: 34em; }
.follow .btn-quiet { background: var(--paper); }
.follow-actions { display: flex; flex-wrap: wrap; gap: 10px; }
@media (max-width: 860px) { .follow-inner { grid-template-columns: 1fr; } }

.site-footer { padding-block: 52px 28px; border-top: 1px solid var(--line); font: 400 15px/1.6 var(--sans); color: var(--ink-2); }
.footer-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr) minmax(0, 1.1fr); gap: 32px 48px; }
.footer-brand p { margin-top: 14px; color: var(--muted); }
.footer-links { display: grid; grid-template-columns: repeat(2, max-content); gap: 10px 40px; align-content: start; }
.footer-links a { text-decoration: none; }
.footer-links a:hover { color: var(--accent-ink); }
.footer-note { font-size: 14px; color: var(--muted); }
.footer-bottom { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--line); font-size: 13.5px; color: var(--muted); }
@media (max-width: 820px) { .footer-grid { grid-template-columns: 1fr; } }

/* ---------------------------------------------------------------- page heads & essays index */
.page-head { padding-block: clamp(48px, 7vw, 96px) clamp(28px, 4vw, 44px); }
.page-head h1 { max-width: 16em; font-size: clamp(2.5rem, 1.7rem + 2.8vw, 3.75rem); line-height: 1.06; letter-spacing: -.025em; margin-bottom: 18px; }
html:lang(zh-CN) .page-head h1 { line-height: 1.3; letter-spacing: .02em; font-size: clamp(2.1rem, 1.5rem + 2.2vw, 3rem); }
.filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 28px; }
.filters button {
  padding: 9px 16px; border: 1px solid var(--line-2); border-radius: 999px; background: transparent;
  color: var(--ink-2); font: 600 15px/1.2 var(--sans); cursor: pointer;
}
.filters button:hover { border-color: var(--ink-2); color: var(--ink); }
.filters button[aria-pressed="true"] { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.filters button span { margin-left: 4px; font-weight: 500; opacity: .65; font-variant-numeric: tabular-nums; }
.essays-index { padding-bottom: clamp(56px, 8vw, 104px); }
.filter-empty { padding: 24px 0; font: 400 16px/1.5 var(--sans); color: var(--muted); }

/* ---------------------------------------------------------------- article */
.article-layout {
  display: grid; grid-template-columns: minmax(0, var(--measure)) minmax(0, 1fr);
  gap: clamp(40px, 7vw, 96px); padding-block: clamp(40px, 6vw, 80px) clamp(40px, 6vw, 72px);
}
.article-head h1 { margin: 14px 0 18px; font-size: clamp(2.2rem, 1.5rem + 2.5vw, 3.2rem); line-height: 1.1; letter-spacing: -.02em; }
html:lang(zh-CN) .article-head h1 { font-size: clamp(1.95rem, 1.4rem + 2vw, 2.7rem); line-height: 1.35; letter-spacing: .02em; }
.article-dek { margin-bottom: 24px; font-size: 1.4rem; line-height: 1.5; color: var(--ink-2); }
html:lang(zh-CN) .article-dek { font-size: 1.18rem; line-height: 1.85; }
.byline {
  display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px 10px;
  padding-bottom: 28px; border-bottom: 1px solid var(--line);
  font: 400 15px/1.5 var(--sans); color: var(--muted);
}
.byline a { color: var(--ink); font-weight: 600; }

.toc { margin: 32px 0 0; padding: 20px 22px; background: var(--band); border-radius: 6px; font-family: var(--sans); }
.toc p { margin-bottom: 10px; font: 700 12px/1.4 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
html:lang(zh-CN) .toc p { font-size: 13px; letter-spacing: .1em; }
.toc ol { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.toc li { display: flex; gap: 10px; font: 500 15.5px/1.45 var(--sans); }
.toc li::before { content: "›"; color: var(--accent); font-weight: 700; }

.prose { margin-top: 36px; }
.prose > * + * { margin-top: 1.15em; }
html:lang(zh-CN) .prose p { text-align: justify; }
.prose h2 { margin-top: 2.1em; font-size: 1.55rem; line-height: 1.3; scroll-margin-top: 24px; }
html:lang(zh-CN) .prose h2 { font-size: 1.36rem; line-height: 1.55; letter-spacing: .02em; }
.prose h2 + * { margin-top: .7em; }
.prose h3 { margin-top: 1.8em; font-size: 1.25rem; line-height: 1.35; }
.prose a { color: var(--ink); }
.prose a:hover { color: var(--accent-ink); }
.prose strong { font-weight: 700; }
html:lang(zh-CN) .prose strong { font-family: var(--sans); font-weight: 600; }
html:lang(zh-CN) .prose em { font-style: normal; color: var(--muted); }
.prose mark.key {
  padding: .08em .18em; border-radius: 2px;
  background: var(--accent-soft); color: var(--ink);
  -webkit-box-decoration-break: clone; box-decoration-break: clone;
}
.prose blockquote { margin-inline: 0; padding: .1em 0 .1em 1.1em; border-left: 3px solid var(--accent); color: var(--ink-2); }
.prose hr { border: 0; border-top: 1px solid var(--line-2); margin-block: 2.4em; }
.prose ul, .prose ol { padding-left: 1.3em; }
.prose li + li { margin-top: .4em; }
.prose code { padding: .1em .35em; border-radius: 3px; background: var(--band); font-size: .85em; }

.article-note { margin-top: 44px; padding-top: 18px; border-top: 1px solid var(--line); font: 400 14px/1.65 var(--sans); color: var(--muted); }
.author-box {
  display: grid; grid-template-columns: 56px minmax(0, 1fr); gap: 18px;
  margin-top: 36px; padding: 24px; background: var(--band); border-radius: 6px;
}
.avatar { display: grid; place-items: center; width: 56px; height: 56px; border-radius: 50%; background: var(--paper); border: 1px solid var(--line-2); }
.avatar-mark { width: 30px; height: 24px; color: var(--accent); }
.author-box h2 { margin-bottom: 6px; font: 700 12px/1.4 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
html:lang(zh-CN) .author-box h2 { font-size: 13px; letter-spacing: .1em; }
.author-box p { font-size: 1.06rem; line-height: 1.6; color: var(--ink-2); }
html:lang(zh-CN) .author-box p { font-size: 1rem; line-height: 1.85; }
.author-actions { display: flex; flex-wrap: wrap; gap: 6px 22px; margin-top: 12px; font: 600 15px/1.4 var(--sans); }

.article-side { font-family: var(--sans); }
.side-sticky { position: sticky; top: 32px; padding-left: 28px; border-left: 1px solid var(--line); }
.side-label { margin-bottom: 14px; font: 700 12px/1.4 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
html:lang(zh-CN) .side-label { font-size: 13px; letter-spacing: .1em; }
.side-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; font-size: 15.5px; }
.side-list a[aria-current="true"] { color: var(--accent-ink); text-decoration-color: currentColor; }
.side-more { margin-top: 28px; padding-top: 18px; border-top: 1px solid var(--line); font: 600 15px/1.4 var(--sans); }
@media (max-width: 1000px) {
  .article-layout { grid-template-columns: minmax(0, 1fr); }
  .article-side { display: none; }
}
.read-next { padding-top: 0; }
.read-next-title { margin-bottom: 18px; font: 700 12.5px/1.4 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
html:lang(zh-CN) .read-next-title { font-size: 14px; letter-spacing: .1em; }

/* ---------------------------------------------------------------- about & 404 */
.about-body { max-width: var(--measure); margin-top: 0; padding-bottom: clamp(56px, 8vw, 104px); }
.about-body > h2:first-child { margin-top: .6em; }
.about-levers { list-style: none; padding: 0; border-top: 1px solid var(--line-2); }
.about-levers li { display: grid; grid-template-columns: 88px minmax(0, 1fr); gap: 16px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.about-levers li + li { margin-top: 0; }
.about-levers b { font: 700 13px/2 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--accent-ink); }
.about-body .principles li + li { margin-top: 0; }
.elsewhere { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: 10px; }
.elsewhere li + li { margin-top: 0; }
.elsewhere a {
  display: inline-flex; align-items: center; gap: 8px; padding: 9px 16px;
  border: 1px solid var(--line-2); border-radius: 999px; font: 600 15px/1.2 var(--sans); text-decoration: none;
}
.elsewhere a:hover { border-color: var(--ink-2); }
.elsewhere svg { width: 15px; height: 15px; }
.not-found { padding-bottom: clamp(56px, 8vw, 104px); }
.not-found .hero-actions { margin: 28px 0 0; }
.not-found-zh { margin-top: 56px; padding-top: 32px; border-top: 1px solid var(--line); font-family: "Noto Serif SC", "Songti SC", serif; }
.not-found-zh h2 { margin-bottom: 10px; font-family: "PingFang SC", "Microsoft YaHei", sans-serif; font-size: 1.6rem; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; }
}