:root {
  --color-surface: #f2f2f1;
  --color-surface-alt: #e9e9e8;
  --color-surface-deep: #dddddb;
  --color-ink: #464539;
  --color-ink-soft: #6d6a5a;
  --color-ink-muted: #8a8775;
  --color-line: #d3d3d0;
  --color-primary: #7d753a;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e2e0d7;
  --color-accent: #b75d24;
  --color-accent-ink: #ffffff;
  --color-highlight: #e7d7cc;
  --color-focus: #b05217;
  --color-contrast-surface: #1a1a13;
  --color-contrast-ink: #e7e6e4;
  --color-contrast-line: #474741;
  --color-contrast-accent: #d56d2a;
  --overlay-scrim: linear-gradient(180deg, rgba(26, 26, 19, 0.35) 0%, rgba(26, 26, 19, 0.72) 55%, rgba(26, 26, 19, 0.92) 100%);
  --font-heading: "Songti SC", "Source Han Serif SC", "Noto Serif SC", SimSun, serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 12.2px;
  --text-sm: 15.2px;
  --text-base: 17px;
  --text-lg: 21.2px;
  --text-xl: 26.6px;
  --text-2xl: 33.2px;
  --text-3xl: 41.5px;
  --text-4xl: 51.9px;
  --text-display: clamp(37px, 7.6vw, 97px);
  --text-figure: clamp(31px, 5.5vw, 70px);
  --weight-heading: 646;
  --weight-body: 400;
  --leading-body: 1.77;
  --leading-heading: 1.25;
  --tracking-heading: 0.006em;
  --radius-sm: 3px;
  --radius-md: 3px;
  --radius-lg: 3px;
  --radius-pill: 3px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 1px 0 rgba(70, 69, 57, 0.12);
  --shadow-2: 0 2px 0 rgba(70, 69, 57, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1160px;
  --measure: 67ch;
  --gutter: 16px;
  --section-y: 93px;
  --section-y-lg: 130px;
}

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

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background-color: var(--color-surface);
  background-image: radial-gradient(color-mix(in srgb, var(--color-line) 42%, transparent) 1px, transparent 1px);
  background-size: 22px 22px;
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; height: auto; }
svg, video { max-width: 100%; }
button { font: inherit; color: inherit; }

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin: 0 0 var(--space-2);
}
h1 { font-size: var(--text-3xl); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }
p { margin: 0 0 var(--space-2); }

a {
  color: var(--color-ink);
  text-decoration: underline;
  text-decoration-style: dotted;
  text-underline-offset: 3px;
}
a:hover { color: var(--color-focus); }

ul, ol { margin: 0; padding: 0; }
li { list-style: none; }

hr { border: 0; }

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

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  border-radius: 2px;
}

#main-content { scroll-margin-top: 168px; }

/* ============ 布局 ============ */
.shell {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding-left: var(--space-3);
  padding-right: var(--space-3);
}

.section { padding-top: var(--section-y); padding-bottom: var(--section-y); }
.section--alt { background: var(--color-surface-alt); }
.section--tight { padding-top: var(--space-8); padding-bottom: var(--space-8); }

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}
.col-2 { grid-column: span 2; }
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-10 { grid-column: span 10; }
.col-12 { grid-column: span 12; }

.prose { max-width: var(--measure); }
.prose p { margin-bottom: var(--space-2); }

/* ============ 文本工具 ============ */
.kicker {
  display: inline-block;
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
  margin: 0 0 var(--space-1);
}

.meta-line {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  margin: 0;
}

.num,
[data-num] {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.readout {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 1;
  letter-spacing: -0.01em;
  display: block;
  color: var(--color-ink);
}

/* ============ 纸片面板 ============ */
.paper-panel {
  position: relative;
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-2);
  padding: var(--space-4);
}
.paper-panel--deep { background: var(--color-surface-deep); }
.paper-panel--alt { background: var(--color-surface-alt); }

.shift-left { transform: translate(-8px, 0); }
.shift-up { transform: translate(0, -14px); }
.shift-right { transform: translate(8px, 0); }

.panel-label {
  position: absolute;
  top: -11px;
  left: var(--space-3);
  display: inline-block;
  padding: 3px 9px;
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  background: var(--color-highlight);
  color: var(--color-ink-soft);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
}

/* ============ 贴纸标签 ============ */
.sticker {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-soft);
  background: var(--color-primary-soft);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
  white-space: nowrap;
}
.sticker--primary { background: var(--color-primary); color: var(--color-primary-ink); }
.sticker--accent { background: var(--color-accent); color: var(--color-accent-ink); }

/* ============ 分隔 ============ */
.rule-dots {
  height: 0;
  border: 0;
  border-top: var(--border-thin) dashed var(--color-line);
  margin: var(--space-4) 0;
  position: relative;
}
.rule-dots::before,
.rule-dots::after {
  content: "";
  position: absolute;
  top: -2px;
  width: 4px;
  height: 4px;
  background: var(--color-line);
  border-radius: 1px;
}
.rule-dots::before { left: 0; }
.rule-dots::after { right: 0; }

/* ============ 按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  min-height: 44px;
  padding: 0 20px;
  font-size: var(--text-sm);
  font-family: inherit;
  color: var(--color-ink);
  background: var(--color-surface);
  border: var(--border-thin) dashed var(--color-line);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
  text-decoration: none;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease, background-color 160ms ease;
}
.btn:hover {
  color: var(--color-ink);
  text-decoration: none;
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-2);
}
.btn--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-color: var(--color-primary);
}
.btn--primary:hover { color: var(--color-primary-ink); }
.btn--accent {
  background: var(--color-accent);
  color: var(--color-accent-ink);
  border-color: var(--color-accent);
}
.btn--accent:hover { color: var(--color-accent-ink); }

/* ============ 分段控件 ============ */
.segmented {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 6px;
  background: var(--color-surface-deep);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
}
.segmented__btn {
  min-height: 44px;
  padding: 0 16px;
  font: inherit;
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  color: var(--color-ink-soft);
  background: var(--color-primary-soft);
  border: 0;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: transform 140ms ease, background-color 140ms ease;
}
.segmented__btn[aria-selected="true"] {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  box-shadow: var(--shadow-1);
}
.segmented__btn:hover { transform: translateY(-2px); }
.segment-panel { padding-top: var(--space-3); }
.segment-panel[hidden] { display: none; }

/* ============ 面包屑 ============ */
.breadcrumb {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  padding: var(--space-3) 0 0;
}
.breadcrumb ol { display: flex; flex-wrap: wrap; gap: 8px; }
.breadcrumb li { display: flex; align-items: center; gap: 8px; }
.breadcrumb li + li::before {
  content: "/";
  color: var(--color-line);
}
.breadcrumb a { text-decoration: none; color: var(--color-ink-muted); }
.breadcrumb a:hover { color: var(--color-focus); }

/* ============ 数据与图例 ============ */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
  background: var(--color-surface);
}
.data-table caption {
  text-align: left;
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
  padding-bottom: var(--space-1);
}
.data-table th,
.data-table td {
  padding: 10px 12px;
  border-bottom: var(--border-thin) dashed var(--color-line);
  text-align: left;
}
.data-table thead th {
  background: var(--color-surface-deep);
  color: var(--color-ink-soft);
  font-weight: var(--weight-body);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
}
.data-table .num { text-align: right; }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
}
.legend__swatch {
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-right: 6px;
  border-radius: 2px;
  background: var(--color-accent);
}
.legend__swatch--primary { background: var(--color-primary); }
.legend__swatch--soft { background: var(--color-primary-soft); }
.legend__swatch--pulse { background: var(--color-contrast-accent); }

/* ============ 深墨区块 ============ */
.contrast-block {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-radius: var(--radius-md);
  padding: var(--space-6) var(--space-4);
  box-shadow: var(--shadow-2);
}
.contrast-block h2,
.contrast-block h3,
.contrast-block h4 { color: var(--color-contrast-ink); }
.contrast-block a { color: var(--color-contrast-accent); }
.contrast-block .readout { color: var(--color-contrast-accent); }
.contrast-block .rule-dots { border-top-color: var(--color-contrast-line); }
.contrast-block .rule-dots::before,
.contrast-block .rule-dots::after { background: var(--color-contrast-line); }
.contrast-block .meta-line,
.contrast-block .kicker { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }

/* ============ 图片容器 ============ */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--color-surface-deep);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-2);
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame > img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.72) contrast(0.96);
  transition: transform 200ms ease;
}
.media-frame:hover > img { transform: scale(1.03); }
.media-frame__scrim {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
}
.media-frame__body {
  position: absolute;
  inset: auto 0 0 0;
  z-index: 1;
  padding: var(--space-3);
  color: var(--color-contrast-ink);
}
.media-frame__body h3,
.media-frame__body h4 { color: var(--color-contrast-ink); }
.media-frame__body p { margin: 0; font-size: var(--text-sm); }

/* ============ 头部 ============ */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -120px;
  z-index: 100;
  padding: 10px 16px;
  font-size: var(--text-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: top 160ms ease;
}
.skip-link:focus { top: var(--space-2); color: var(--color-primary-ink); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--color-surface);
  border-bottom: var(--border-thin) dashed var(--color-line);
  box-shadow: var(--shadow-1);
}
.header-shell { padding-top: var(--space-3); padding-bottom: var(--space-1); }

.masthead {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: var(--space-2);
  padding-bottom: var(--space-2);
  border-bottom: var(--border-thin) dashed var(--color-line);
}
.masthead-kicker {
  margin: 0;
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-ink-muted);
  justify-self: start;
}
.masthead-brand {
  justify-self: center;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-3xl);
  letter-spacing: 0.18em;
  line-height: 1.1;
  color: var(--color-ink);
  text-decoration: none;
}
.masthead-brand:hover { color: var(--color-ink); text-decoration: none; }
.masthead-side {
  justify-self: end;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 6px;
}

.season-switch { display: inline-flex; gap: 4px; }
.season-switch__btn {
  min-height: 30px;
  padding: 0 9px;
  font: inherit;
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  background: transparent;
  border: var(--border-thin) dashed var(--color-line);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background-color 140ms ease, color 140ms ease;
}
.season-switch__btn:hover { background: var(--color-surface-deep); color: var(--color-ink); }
.season-switch__btn[aria-pressed="true"] {
  background: var(--color-primary-soft);
  color: var(--color-ink);
  border-style: solid;
  border-color: var(--color-primary);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  margin-top: var(--space-1);
  padding: 0 14px;
  font: inherit;
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  color: var(--color-ink);
  background: var(--color-surface-alt);
  border: var(--border-thin) dashed var(--color-line);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
  cursor: pointer;
}
.nav-toggle__bars {
  width: 16px;
  height: 11px;
  background:
    linear-gradient(currentColor, currentColor) 0 0 / 100% 1px no-repeat,
    linear-gradient(currentColor, currentColor) 0 5px / 100% 1px no-repeat,
    linear-gradient(currentColor, currentColor) 0 10px / 100% 1px no-repeat;
}

.primary-nav { margin-top: var(--space-1); }
.nav-ruler {
  display: flex;
  gap: var(--space-1);
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}
.nav-ruler__item { flex: 0 0 auto; }
.nav-ruler a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-ink-soft);
  border-radius: var(--radius-sm);
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 140ms ease, transform 140ms ease;
}
.nav-ruler a:hover {
  background: var(--color-surface-deep);
  color: var(--color-ink);
  transform: translateY(-2px);
}
.nav-ruler a[aria-current="page"] {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  box-shadow: var(--shadow-1);
}

.scroll-meter {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: 0 50%;
}

/* ============ 页脚 ============ */
.site-footer {
  margin-top: var(--section-y-lg);
  padding-top: var(--space-8);
  padding-bottom: var(--space-4);
  background: var(--color-surface-alt);
  border-top: var(--border-thin) dashed var(--color-line);
}
.footer-shell { position: relative; }
.footer-stack {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr 1fr;
  gap: var(--space-3);
  align-items: start;
}
.footer-panel { padding-top: var(--space-4); }
.footer-panel--archive { transform: translateY(-14px); }
.footer-panel--legal { transform: translateY(8px); }

.footer-panel__title {
  font-size: var(--text-lg);
  margin-bottom: var(--space-2);
}
.footer-list { display: grid; }
.footer-list li {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 9px 0;
  font-size: var(--text-sm);
  border-bottom: var(--border-thin) dashed var(--color-line);
}
.footer-list li:last-child { border-bottom: 0; }
.footer-key {
  min-width: 5.5em;
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}
.footer-links { display: grid; gap: 2px; }
.footer-links a {
  display: block;
  padding: 9px 0;
  font-size: var(--text-sm);
  text-decoration: none;
  border-bottom: var(--border-thin) dashed var(--color-line);
  transition: padding-left 140ms ease, color 140ms ease;
}
.footer-links li:last-child a { border-bottom: 0; }
.footer-links a:hover { padding-left: 6px; color: var(--color-focus); }
.footer-note {
  margin: var(--space-2) 0 0;
  font-size: var(--text-xs);
  line-height: 1.7;
  color: var(--color-ink-muted);
}
.footer-legal {
  margin: var(--space-8) 0 0;
  padding-top: var(--space-2);
  border-top: var(--border-thin) dashed var(--color-line);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  text-align: center;
}

/* ============ 响应式 ============ */
@media (max-width: 960px) {
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-2, .col-3 { grid-column: span 3; }
  .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-10 { grid-column: span 6; }
  .col-12 { grid-column: span 6; }
  .shift-left, .shift-up, .shift-right { transform: none; }
}

@media (max-width: 880px) {
  .masthead { grid-template-columns: 1fr; justify-items: start; gap: var(--space-1); }
  .masthead-kicker { justify-self: start; }
  .masthead-brand { justify-self: start; font-size: var(--text-xl); letter-spacing: 0.14em; }
  .masthead-side { justify-self: start; align-items: flex-start; }
  .nav-toggle { display: inline-flex; }
  .primary-nav { display: none; margin-top: var(--space-1); }
  .primary-nav[data-open="true"] { display: block; }
  .nav-ruler { flex-direction: column; overflow: visible; gap: 2px; padding-bottom: 0; }
  .nav-ruler a { width: 100%; }
  .footer-stack { grid-template-columns: 1fr; gap: var(--space-4); }
  .footer-panel--archive, .footer-panel--legal { transform: none; }
  .footer-legal { margin-top: var(--space-6); }
}

@media (max-width: 620px) {
  :root { --section-y: 64px; --section-y-lg: 80px; }
  .grid-12 { grid-template-columns: 1fr; }
  .col-2, .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-10, .col-12 { grid-column: span 1; }
  .paper-panel { padding: var(--space-3); }
  .contrast-block { padding: var(--space-4) var(--space-3); }
  .readout { font-size: var(--text-4xl); }
}

/* ============ 动效可访问性 ============ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .btn:hover { transform: none; }
  .nav-ruler a:hover { transform: none; }
  .segmented__btn:hover { transform: none; }
  .media-frame:hover > img { transform: none; }
  .footer-links a:hover { padding-left: 0; }
}