/* ============================================================
 * 闭门会文章页：阅读优先，PC / 移动同一套骨架
 * ============================================================ */

:root {
  --paper: #e5e5e5;
  --ink: #1a1a1a;
  --muted: #5c5e60;
  --line: rgba(71, 73, 75, 0.18);
  --line-strong: rgba(71, 73, 75, 0.32);
  --charcoal: #47494b;
  --soft: rgba(255, 255, 255, 0.42);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
}

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

::selection {
  background: var(--charcoal);
  color: var(--paper);
}

/* ---------- 顶栏 ---------- */

.site-nav {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(229, 229, 229, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.site-nav-inner {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  min-height: 72px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: "Noto Serif SC", serif;
  font-weight: 700;
  letter-spacing: 0.12em;
  font-size: 18px;
}

.brand-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--ink);
}

.brand i {
  font-style: normal;
  font-family: Inter, sans-serif;
  font-weight: 400;
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin-left: 2px;
}

.nav-links {
  display: none;
  margin-left: auto;
  gap: 28px;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.04em;
}

.nav-links a:hover { color: var(--charcoal); }

.nav-cta {
  display: none;
  padding: 10px 18px;
  background: var(--charcoal);
  color: var(--paper);
  font-size: 13px;
  font-weight: 500;
}

.nav-cta:hover { background: #000; }

.nav-toggle {
  margin-left: auto;
  width: 40px;
  height: 40px;
  font-size: 22px;
}

.nav-mobile {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 8px 20px 24px;
  font-size: 14px;
  font-weight: 500;
  border-top: 1px solid var(--line);
}

.nav-mobile[hidden] { display: none !important; }

.nav-mobile .nav-cta {
  display: inline-flex;
  width: max-content;
  margin-top: 4px;
}

@media (min-width: 860px) {
  .nav-links,
  .site-nav-inner > .nav-cta { display: flex; }
  .nav-toggle,
  .nav-mobile { display: none !important; }
}

/* ---------- 正文栏 ---------- */

.sheet {
  width: min(720px, calc(100% - 40px));
  margin: 0 auto;
  padding: 40px 0 72px;
}

.hero { margin-bottom: 40px; }

.hero-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.kicker {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.share {
  flex-shrink: 0;
  padding: 6px 12px;
  border: 1px solid var(--line-strong);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.share:hover,
.share.is-done {
  border-color: var(--charcoal);
  color: var(--ink);
}

.hero h1 {
  margin: 0 0 16px;
  font-family: "Noto Serif SC", serif;
  font-size: clamp(28px, 5vw, 42px);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.byline {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.body {
  font-size: 18px;
  font-weight: 300;
  line-height: 1.9;
  color: var(--muted);
}

.body p { margin: 0 0 1.3em; }

.body h2,
.body h3,
.body h4 {
  margin: 2.4em 0 0.8em;
  font-family: "Noto Serif SC", serif;
  font-size: clamp(22px, 3vw, 28px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--ink);
}

.body h2:first-child,
.body h3:first-child { margin-top: 0; }

.body hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 2.4em 0;
}

.body blockquote {
  margin: 1.6em 0;
  padding: 0.15em 0 0.15em 1.1em;
  border-left: 2px solid var(--line-strong);
  color: var(--ink);
}

.body blockquote p { margin: 0; }

.body ul,
.body ol {
  margin: 0 0 1.4em;
  padding-left: 1.2em;
}

.body li {
  margin: 0 0 0.7em;
  padding-left: 0.2em;
}

.body li::marker { color: var(--charcoal); }

.body a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.28em;
  text-decoration-color: rgba(71, 73, 75, 0.4);
}

.body a:hover { text-decoration-color: var(--ink); }

.body img {
  display: block;
  width: 100%;
  height: auto;
  margin: 2rem 0;
}

.body #signup {
  scroll-margin-top: 88px;
}

.body img:first-child { margin-top: 0; }

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

.body .origin {
  margin-top: 2.5em;
  font-size: 14px;
}

/* ---------- 翻页 ---------- */

.pager {
  display: grid;
  gap: 12px;
  margin-top: 56px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.pager-slot {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  background: var(--soft);
  border: 1px solid var(--line);
  min-height: 88px;
}

a.pager-slot:hover {
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, 0.62);
}

.pager-slot.is-empty { opacity: 0.55; }

.pager-kicker {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.pager-title {
  font-family: "Noto Serif SC", serif;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.4;
}

.pager-index { justify-content: center; }

@media (min-width: 760px) {
  .sheet { padding-top: 56px; padding-bottom: 96px; }
  .pager {
    grid-template-columns: 1fr 160px 1fr;
    align-items: stretch;
  }
  .pager-index {
    text-align: center;
    align-items: center;
  }
  .pager-next { text-align: right; }
}

/* ---------- 页脚 ---------- */

.site-foot {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  background: var(--charcoal);
  color: rgba(229, 229, 229, 0.6);
  padding: 28px 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  font-size: 13px;
}

.site-foot > div:first-child {
  font-family: "Noto Serif SC", serif;
  letter-spacing: 0.14em;
}

.site-foot i {
  font-style: normal;
  font-family: Inter, sans-serif;
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.site-foot a {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.site-foot a:hover { color: #fff; }

@media (min-width: 760px) {
  .site-foot {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    padding: 32px min(48px, calc((100% - 1120px) / 2 + 48px));
  }
}

@media (max-width: 640px) {
  .body { font-size: 17px; line-height: 1.85; }
  .share { font-size: 11px; padding: 6px 10px; }
}