/* =========================================================
   /assets/site.css — 四季指南 全站共享样式
   结构：reset → 变量 → 基础排版 → 页眉导轨 → 页脚 →
        容器/网格 → 通用组件 → 响应式 → 动效降级
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd, ul, ol { margin: 0; }

ul, ol { padding: 0; }

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

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

a { color: inherit; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.site-footer :focus-visible { outline-color: var(--accent-soft); }

/* ---------- 2. 变量 ---------- */
:root {
  /* 自然矿物色 */
  --paper: #F7F2E8;
  --surface: #FCFAF2;
  --frost: #E9EFEC;
  --rock: #4C514C;
  --ink: #232825;
  --moss: #6F8B6A;
  --sprout: #A9C79E;
  --blush: #D8B7B1;
  --lake: #5E93AA;
  --sun: #E2B84C;
  --clay: #B46848;
  --wheat: #C49A55;
  --indigo: #2E3A55;

  /* 结构线 */
  --line: rgba(76, 81, 76, 0.22);
  --line-soft: rgba(76, 81, 76, 0.12);
  --grid: rgba(76, 81, 76, 0.07);

  /* 当季强调（默认春） */
  --accent: #6F8B6A;
  --accent-soft: #A9C79E;
  --accent-deep: #4F6A4B;
  --accent-tint: rgba(111, 139, 106, 0.14);

  /* 尺度 */
  --rail-w: 272px;
  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-pill: 999px;
  --shadow-soft: 0 18px 40px -28px rgba(35, 40, 37, 0.45);

  /* 字体 */
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --font-sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "IBM Plex Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* 阅读进度（由 JS 写入） */
  --progress: 0;
}

:root[data-season="spring"] {
  --accent: #6F8B6A;
  --accent-soft: #A9C79E;
  --accent-deep: #4F6A4B;
  --accent-tint: rgba(111, 139, 106, 0.14);
}
:root[data-season="summer"] {
  --accent: #5E93AA;
  --accent-soft: #8FBFD0;
  --accent-deep: #406B7D;
  --accent-tint: rgba(94, 147, 170, 0.14);
}
:root[data-season="autumn"] {
  --accent: #B46848;
  --accent-soft: #C49A55;
  --accent-deep: #8B4C33;
  --accent-tint: rgba(180, 104, 72, 0.14);
}
:root[data-season="winter"] {
  --accent: #2E3A55;
  --accent-soft: #9FB0C4;
  --accent-deep: #1F2940;
  --accent-tint: rgba(46, 58, 85, 0.12);
}

/* ---------- 3. 基础排版 ---------- */
body {
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.28;
  letter-spacing: 0;
}

h1 { font-size: clamp(2.125rem, 1.35rem + 2.6vw, 4rem); line-height: 1.16; }
h2 { font-size: clamp(1.75rem, 1.3rem + 1.4vw, 2.375rem); }
h3 { font-size: clamp(1.25rem, 1.1rem + 0.6vw, 1.625rem); }
h4 { font-size: 1.125rem; }

p { line-height: 1.8; }

/* ---------- 4. 通用工具类 ---------- */
.mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.text-accent { color: var(--accent-deep); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--rock);
}
.eyebrow::before {
  content: "";
  width: 18px;
  height: 1px;
  background: var(--accent);
}

.rule {
  height: 1px;
  border: 0;
  margin: 0;
  background: var(--line);
}
.rule--accent { background: var(--accent); }

/* ---------- 5. 跳到主要内容 ---------- */
.skip-link {
  position: absolute;
  top: 10px;
  left: 12px;
  z-index: 300;
  transform: translateY(-180%);
  padding: 10px 16px;
  border-radius: var(--radius-pill);
  background: var(--ink);
  color: var(--paper);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.18s ease;
}
.skip-link:focus { transform: translateY(0); }

#main-content {
  display: block;
  scroll-margin-top: 92px;
}

/* ---------- 6. 页眉：左侧导轨 ---------- */
.site-header {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 22px 18px 18px;
  background-color: var(--paper);
  background-image: repeating-linear-gradient(0deg, var(--grid) 0 1px, transparent 1px 56px);
  border-right: 1px solid var(--line);
  z-index: 60;
}

.site-header__bar {
  display: flex;
  flex-direction: column;
  gap: 18px;
  flex: none;
}

.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  color: var(--ink);
}

.brand__mark {
  position: relative;
  width: 38px;
  height: 38px;
  flex: none;
  border-radius: 11px;
  overflow: hidden;
  background: var(--accent);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.22);
}
.brand__mark::before {
  content: "";
  position: absolute;
  left: -26%;
  right: -26%;
  bottom: -22%;
  height: 58%;
  background: var(--accent-soft);
  transform: rotate(-18deg);
}
.brand__mark::after {
  content: "";
  position: absolute;
  top: 9px;
  left: 9px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--paper);
  opacity: 0.92;
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.brand__name {
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.08em;
  line-height: 1.2;
}

.brand__descriptor {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.2em;
  line-height: 1.4;
  color: var(--rock);
  white-space: nowrap;
}

/* 季节胶囊 */
.season-switcher {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--line-soft);
}

.season-switcher__label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.22em;
  color: var(--rock);
}

.season-switcher__pills { display: flex; gap: 6px; }

.season-pill {
  position: relative;
  flex: 1 1 0;
  min-width: 0;
  overflow: hidden;
  padding: 6px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  color: var(--rock);
  font-family: var(--font-sans);
  font-size: 13px;
  line-height: 1.4;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}
.season-pill::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--accent-tint);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.3s ease;
}
.season-pill:hover::before { transform: scaleX(1); }
.season-pill:hover { color: var(--ink); border-color: var(--accent); }

.season-pill.is-current,
.season-pill[aria-current="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  font-weight: 600;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.25);
}
.season-pill.is-current::before,
.season-pill[aria-current="true"]::before { display: none; }

/* 抽屉按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--surface);
  color: var(--ink);
  font-size: 13px;
  cursor: pointer;
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 10px;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 1.5px;
  background: var(--ink);
  transition: transform 0.24s ease;
}
.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { bottom: 0; }

.nav-toggle__text {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
}

.site-header[data-open] .nav-toggle__bars::before { transform: translateY(4.2px) rotate(45deg); }
.site-header[data-open] .nav-toggle__bars::after { transform: translateY(-4.2px) rotate(-45deg); }

/* 导航面板 */
.site-header__nav {
  display: flex;
  flex-direction: column;
  gap: 18px;
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
}

.nav-close {
  display: none;
  align-self: flex-end;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--rock);
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease;
}
.nav-close:hover { border-color: var(--accent); color: var(--accent-deep); }

.site-nav__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.site-nav__item { list-style: none; }

.site-nav__link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 10px 10px 8px;
  border-left: 2px solid transparent;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--ink);
  font-size: 15px;
  line-height: 1.5;
  text-decoration: none;
  transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.2s ease, color 0.2s ease;
}

.site-nav__index {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--rock);
  min-width: 18px;
}

.site-nav__label { flex: 1 1 auto; }

.site-nav__link:hover {
  background: var(--accent-tint);
  border-left-color: var(--accent);
  transform: translateX(2px);
}

.site-nav__link[aria-current="page"] {
  background: var(--accent-tint);
  border-left-color: var(--accent);
  font-weight: 600;
}
.site-nav__link[aria-current="page"] .site-nav__index { color: var(--accent-deep); }

.site-header__utility {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--line-soft);
}
.site-header__utility .btn { width: 100%; }

.site-header__meta {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  line-height: 1.8;
  color: var(--rock);
}

/* 阅读进度刻度 */
.rail-progress {
  position: absolute;
  top: 0;
  right: -1px;
  bottom: 0;
  width: 2px;
  pointer-events: none;
}

.rail-progress__fill {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--accent);
  transform: scaleY(var(--progress, 0));
  transform-origin: top center;
  transition: transform 0.1s linear;
}

.nav-scrim { display: none; }

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  line-height: 1.3;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease, transform 0.12s ease;
}

.btn--solid {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.btn--solid:hover {
  background: var(--accent-deep);
  border-color: var(--accent-deep);
  color: #fff;
}

.btn--ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--ink);
}
.btn--ghost:hover {
  border-color: var(--accent);
  background: var(--accent-tint);
  color: var(--accent-deep);
}

.btn--accent {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}
.btn--accent:hover {
  background: #101310;
  border-color: #101310;
  color: var(--paper);
}

.btn--sm {
  min-height: 36px;
  padding: 0 14px;
  font-size: 13px;
}

.btn:active {
  transform: translateY(1px);
  box-shadow: inset 0 2px 6px rgba(35, 40, 37, 0.28);
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 110px);
  background: var(--ink);
  color: var(--frost);
  border-top: 2px solid var(--accent);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, rgba(233, 239, 236, 0.06) 0 1px, transparent 1px 64px),
    repeating-linear-gradient(90deg, rgba(233, 239, 236, 0.06) 0 1px, transparent 1px 64px);
  pointer-events: none;
}

.footer__grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.5fr 0.8fr 0.8fr 1.2fr;
  gap: clamp(24px, 3.4vw, 56px);
  padding-block: clamp(44px, 6vw, 76px);
  border-bottom: 1px solid rgba(233, 239, 236, 0.14);
}

.footer__brand { min-width: 0; }

.footer__wordmark {
  font-family: var(--font-serif);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 0.08em;
  line-height: 1.3;
  color: var(--frost);
}

.footer__tagline {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  line-height: 1.8;
  color: rgba(233, 239, 236, 0.62);
}

.footer__summary {
  margin-top: 16px;
  max-width: 30em;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(233, 239, 236, 0.74);
}

.footer__col { min-width: 0; }

.footer__col-title {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--accent-soft);
}

.footer__links {
  list-style: none;
  display: grid;
  gap: 10px;
}
.footer__links li { list-style: none; }
.footer__links a {
  display: inline-block;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(233, 239, 236, 0.82);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.footer__links a:hover {
  color: var(--frost);
  border-bottom-color: var(--accent-soft);
}

.footer__contact { min-width: 0; }

.footer__contact-item {
  display: flex;
  gap: 10px;
  margin-bottom: 10px;
  font-size: 14px;
  line-height: 1.7;
}

.footer__contact-label {
  flex: none;
  min-width: 34px;
  padding-top: 2px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  color: rgba(233, 239, 236, 0.62);
}

.footer__contact-value {
  color: var(--frost);
  overflow-wrap: anywhere;
}

.footer__note {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid rgba(233, 239, 236, 0.14);
  font-size: 12px;
  line-height: 1.8;
  color: rgba(233, 239, 236, 0.6);
}

.footer__base {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 28px;
  padding-block: 20px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: rgba(233, 239, 236, 0.62);
}

.footer__legal {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  list-style: none;
}
.footer__legal li { list-style: none; }
.footer__legal a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.footer__legal a:hover {
  color: var(--frost);
  border-bottom-color: var(--accent-soft);
}

.footer__icp { white-space: nowrap; }

.footer__copy { white-space: nowrap; }

/* ---------- 9. 容器与网格 ---------- */
.container {
  width: min(100% - 40px, 1120px);
  margin-inline: auto;
}

.container--narrow {
  width: min(100% - 40px, 760px);
  margin-inline: auto;
}

.grid {
  display: grid;
  gap: clamp(18px, 2.6vw, 36px);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--7-5 { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
.grid--8-4 { grid-template-columns: minmax(0, 8fr) minmax(0, 4fr); }

/* ---------- 10. 正文长文 ---------- */
.prose {
  max-width: 36em;
  font-size: 17px;
  line-height: 1.85;
  color: var(--ink);
}

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

.prose h2 {
  margin-top: 2.2em;
  font-size: clamp(1.5rem, 1.2rem + 0.9vw, 2rem);
}

.prose h3 {
  margin-top: 1.8em;
  font-size: clamp(1.15rem, 1.05rem + 0.4vw, 1.35rem);
}

.prose ul,
.prose ol { padding-left: 1.3em; }
.prose li + li { margin-top: 0.45em; }

.prose a {
  color: var(--accent-deep);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  text-decoration-color: var(--accent-soft);
}
.prose a:hover { text-decoration-color: var(--accent); }

.prose strong { font-weight: 600; }

.prose blockquote {
  border-left: 2px solid var(--accent);
  padding-left: 18px;
  font-family: var(--font-serif);
  font-size: 1.05em;
  color: var(--rock);
}

.prose hr {
  height: 1px;
  border: 0;
  margin: 2em 0;
  background: var(--line);
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: var(--frost);
  padding: 2px 6px;
  border-radius: 6px;
}

/* ---------- 11. 章节头 / 面包屑 / 标签 ---------- */
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px 20px;
  margin-bottom: 28px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.section-head__title { font-size: clamp(1.4rem, 1.15rem + 0.9vw, 1.875rem); }

.section-head__note {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--rock);
}

.breadcrumb {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--rock);
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
}
.breadcrumb__list li { list-style: none; }

.breadcrumb__list a {
  color: var(--rock);
  text-decoration: none;
  transition: color 0.2s ease;
}
.breadcrumb__list a:hover { color: var(--accent-deep); }

.breadcrumb__sep { color: var(--line); }

.tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--frost);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  line-height: 1.6;
  color: var(--rock);
}

.tag--accent {
  border-color: transparent;
  background: var(--accent-tint);
  color: var(--accent-deep);
}

/* ---------- 12. 面板 / 索引卡 ---------- */
.panel {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: clamp(20px, 3vw, 32px);
  background: var(--surface);
}

.panel--tint {
  background: var(--frost);
  border-color: transparent;
}

.panel--accent {
  background: var(--accent-tint);
  border-color: transparent;
}

.index-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.index-card::after {
  content: "";
  position: absolute;
  top: 12px;
  right: 12px;
  width: 8px;
  height: 8px;
  border-top: 1px solid var(--accent);
  border-right: 1px solid var(--accent);
  opacity: 0.7;
  transition: opacity 0.2s ease;
}

.index-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-soft);
}
.index-card:hover::after { opacity: 1; }

.index-card__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--rock);
}

.index-card__title {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.4;
}

.index-card__text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--rock);
}

/* ---------- 13. 时间轴（更新日志式叙事） ---------- */
.timeline {
  position: relative;
  list-style: none;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--line);
}

.timeline__item {
  position: relative;
  padding-left: 30px;
  list-style: none;
}
.timeline__item + .timeline__item { margin-top: 22px; }

.timeline__item::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 8px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--accent);
}

.timeline__label {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--accent-deep);
}

.timeline__body {
  font-size: 15px;
  line-height: 1.75;
  color: var(--rock);
}

/* ---------- 14. 图片容器（页面阶段放占位/图片） ---------- */
.figure { margin: 0; }

.figure__media {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(150deg, var(--frost), var(--paper));
  aspect-ratio: 4 / 3;
}

.figure__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure__media:empty::after {
  content: "图 · IMAGE";
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--rock);
  background-image:
    linear-gradient(135deg, transparent 0 49.6%, var(--line-soft) 49.6% 50.4%, transparent 50.4%),
    linear-gradient(200deg, transparent 0 76%, rgba(76, 81, 76, 0.06) 76%);
}

.figure__media--wide { aspect-ratio: 16 / 9; }
.figure__media--tall { aspect-ratio: 3 / 4; }
.figure__media--square { aspect-ratio: 1 / 1; }

.figure__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--rock);
}

/* ---------- 15. 桌面外壳偏移 ---------- */
@media (min-width: 901px) {
  body { padding-left: var(--rail-w); }
}

/* 页眉滚动状态 */
.site-header.is-scrolled { box-shadow: 0 1px 0 var(--line-soft); }

/* ---------- 16. 移动 / 平板 ---------- */
@media (max-width: 900px) {
  body {
    padding-left: 0;
    font-size: 16px;
  }

  body.nav-open { overflow: hidden; }

  .site-header {
    position: sticky;
    inset: auto;
    top: 0;
    width: 100%;
    gap: 0;
    padding: 0;
    background-image: none;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    box-shadow: 0 10px 24px -24px rgba(35, 40, 37, 0.6);
  }

  .site-header.is-scrolled { box-shadow: 0 14px 30px -26px rgba(35, 40, 37, 0.65); }

  .site-header__bar {
    flex-direction: row;
    align-items: center;
    gap: 10px;
    padding: 9px 14px;
  }

  .brand { gap: 8px; }
  .brand__mark { width: 30px; height: 30px; border-radius: 9px; }
  .brand__mark::after { top: 7px; left: 7px; width: 9px; height: 9px; }
  .brand__name { font-size: 16px; letter-spacing: 0.06em; }
  .brand__descriptor { display: none; }

  .season-switcher {
    flex-direction: row;
    align-items: center;
    gap: 6px;
    margin-left: auto;
    padding-top: 0;
    border-top: 0;
  }
  .season-switcher__label { display: none; }
  .season-switcher__pills { gap: 4px; }
  .season-pill {
    flex: 0 0 auto;
    width: 30px;
    padding: 5px 0;
    font-size: 12px;
  }

  .nav-toggle { display: inline-flex; }

  .site-header__nav {
    position: fixed;
    inset: 0 auto 0 0;
    width: min(320px, 84vw);
    gap: 16px;
    padding: 18px 16px 26px;
    background: var(--paper);
    background-image: repeating-linear-gradient(0deg, var(--grid) 0 1px, transparent 1px 56px);
    border-right: 1px solid var(--line);
    box-shadow: 24px 0 60px -40px rgba(35, 40, 37, 0.6);
    visibility: hidden;
    transform: translateX(-104%);
    transition: transform 0.3s ease, visibility 0.3s ease;
    z-index: 90;
    overflow-y: auto;
  }

  .site-header[data-open] .site-header__nav {
    visibility: visible;
    transform: translateX(0);
  }

  .nav-close { display: inline-flex; }

  .site-header__utility {
    flex-direction: row;
    flex-wrap: wrap;
  }
  .site-header__utility .btn { flex: 1 1 auto; width: auto; }

  .site-header__meta { margin-top: 0; }

  .rail-progress {
    top: auto;
    left: 0;
    right: 0;
    bottom: -1px;
    width: auto;
    height: 2px;
  }
  .rail-progress__fill {
    width: 100%;
    height: 100%;
    transform: scaleX(var(--progress, 0));
    transform-origin: left center;
  }

  .site-header[data-open] .nav-scrim {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(35, 40, 37, 0.42);
    cursor: pointer;
    z-index: 80;
  }

  .container,
  .container--narrow { width: calc(100% - 32px); }

  .grid--2,
  .grid--3,
  .grid--7-5,
  .grid--8-4 { grid-template-columns: minmax(0, 1fr); }

  .footer__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
  }
  .footer__brand { grid-column: 1 / -1; }
  .footer__contact { grid-column: 1 / -1; }

  .footer__base { gap: 10px 20px; }
}

@media (max-width: 560px) {
  .footer__grid { grid-template-columns: minmax(0, 1fr); }
  .footer__col,
  .footer__brand,
  .footer__contact { grid-column: auto; }
  .footer__base { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 360px) {
  .brand__name { font-size: 15px; }
  .season-pill { width: 27px; font-size: 11px; }
  .nav-toggle { padding: 7px 10px; }
}

/* ---------- 17. 动效降级 ---------- */
@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;
  }

  .site-nav__link:hover { transform: none; }
  .index-card:hover { transform: none; }
  .btn:active { transform: none; }
  .season-pill::before { transition: none; }
  .rail-progress__fill { transition: none; }
  .skip-link { transition: none; }
}