:root {
  --color-surface: #f6f7f7;
  --color-surface-alt: #edeeee;
  --color-surface-deep: #e0e2e2;
  --color-ink: #3b4947;
  --color-ink-soft: #5c706d;
  --color-ink-muted: #748b88;
  --color-line: #d4d8d7;
  --color-primary: #2d8075;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #dae6e5;
  --color-accent: #996a3d;
  --color-accent-ink: #ffffff;
  --color-highlight: #e5ded6;
  --color-focus: #98622f;
  --color-contrast-surface: #1b2a28;
  --color-contrast-ink: #e4e7e6;
  --color-contrast-line: #475452;
  --color-contrast-accent: #b98350;
  --overlay-scrim: linear-gradient(180deg, rgba(27, 42, 40, 0.35) 0%, rgba(27, 42, 40, 0.72) 55%, rgba(27, 42, 40, 0.92) 100%);
  --font-heading: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-body: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, 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(39px, 8.0vw, 103px);
  --text-figure: clamp(33px, 5.8vw, 74px);
  --weight-heading: 690;
  --weight-body: 400;
  --leading-body: 1.79;
  --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: 2px;
  --shadow-1: 0 1px 0 rgba(59, 73, 71, 0.12);
  --shadow-2: 0 2px 0 rgba(59, 73, 71, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1180px;
  --measure: 69ch;
  --gutter: 24px;
  --section-y: 100px;
  --section-y-lg: 140px;
}

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

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

body {
  margin: 0;
  background-color: var(--color-surface);
  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;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

p { margin: 0 0 var(--space-3); }

a { color: var(--color-primary); text-decoration: none; }

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

table { border-collapse: collapse; width: 100%; }

hr { border: 0; height: var(--border-thin); background: var(--color-line); margin: var(--space-6) 0; }

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

/* ============================================================
   中文排版
   ============================================================ */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-3);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }
h5 { font-size: var(--text-base); }

p, li, dd, dt, figcaption, td, th { line-height: var(--leading-body); }

p, .prose p { max-width: var(--measure); }

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

small { font-size: var(--text-xs); }

.mono { font-family: var(--font-mono); font-weight: 600; font-variant-numeric: tabular-nums; letter-spacing: -0.01em; }

.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;
}

/* ============================================================
   焦点与可达性
   ============================================================ */
:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

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

.section { padding: var(--section-y) 0; }
.section--lg { padding: var(--section-y-lg) 0; }
.section--tight { padding: var(--space-6) 0; }

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--space-3);
}

.grid--wide { gap: var(--space-4); }
.grid--loose { gap: var(--space-6); }

.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-12 { grid-column: span 12; }

/* ============================================================
   skip link
   ============================================================ */
.skip-link {
  position: fixed;
  left: var(--space-3);
  top: -80px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  transition: top 0.18s ease;
}

.skip-link:focus { top: var(--space-2); }

/* ============================================================
   阅读进度
   ============================================================ */
.scroll-progress {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--border-thick);
  background: color-mix(in srgb, var(--color-line) 72%, transparent);
  z-index: 150;
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.12s linear;
  will-change: transform;
}

/* ============================================================
   头部：悬浮胶囊
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: var(--space-1) var(--space-3) 0;
}

.header-island {
  position: relative;
  max-width: var(--container);
  margin: 0 auto;
  background: color-mix(in srgb, var(--color-primary-soft) 58%, var(--color-surface) 42%);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-1);
  backdrop-filter: blur(6px);
}

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 10px 12px 10px var(--space-3);
}

/* 品牌 */
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  color: var(--color-ink);
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  flex: 0 0 30px;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  line-height: 1;
}

.brand-text { display: flex; flex-direction: column; gap: 2px; }

.brand-name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-base);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--color-ink);
}

.brand-sub {
  font-size: var(--text-xs);
  line-height: 1.1;
  letter-spacing: 0.22em;
  color: var(--color-ink-muted);
}

/* 竖排小标注 */
.vmark {
  flex: 0 0 auto;
  writing-mode: vertical-rl;
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  line-height: 1;
  letter-spacing: 0.3em;
  color: var(--color-accent);
  padding: 0 2px 0 6px;
  border-left: var(--border-thin) solid color-mix(in srgb, var(--color-accent) 42%, transparent);
}

/* 主导航 */
.site-nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
  min-width: 0;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  flex-wrap: nowrap;
}

.nav-list a {
  display: block;
  padding: 8px 13px;
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
  white-space: nowrap;
  color: var(--color-ink-soft);
  transition: background-color 0.18s ease, color 0.18s ease;
}

.nav-list a:hover {
  color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 12%, transparent);
}

.nav-list a[aria-current="page"] {
  color: var(--color-primary-ink);
  background: var(--color-primary);
}

/* 右侧工具区 */
.header-tools {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex: 0 0 auto;
}

/* 轮次切换器 */
.round-switch { position: relative; }

.round-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  background: var(--color-accent);
  color: var(--color-accent-ink);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  transition: background-color 0.18s ease;
}

.round-toggle:hover { background: var(--color-focus); }

.round-key { opacity: 0.78; }

.round-value {
  font-family: var(--font-mono);
  font-weight: 700;
  letter-spacing: 0;
  font-variant-numeric: tabular-nums;
}

.round-caret {
  width: 6px;
  height: 6px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg) translateY(-2px);
  transition: transform 0.18s ease;
}

.round-toggle[aria-expanded="true"] .round-caret {
  transform: rotate(-135deg) translateY(-2px);
}

.round-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  min-width: 244px;
  padding: var(--space-1);
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-2);
  display: none;
  z-index: 120;
}

.round-menu[data-open] { display: block; }

.round-menu a {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
  padding: 9px 10px;
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  transition: background-color 0.18s ease, color 0.18s ease;
}

.round-menu a:hover { background: var(--color-primary-soft); color: var(--color-ink); }

.round-menu-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-sm);
  color: var(--color-accent);
  font-variant-numeric: tabular-nums;
}

.round-menu-note { font-size: var(--text-xs); color: var(--color-ink-muted); }

/* 移动端栏目按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 11px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-soft);
  color: var(--color-ink);
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
}

.nav-toggle-bars {
  position: relative;
  width: 16px;
  height: 10px;
  flex: 0 0 16px;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 1.5px;
  background: currentColor;
  transition: transform 0.18s ease, top 0.18s ease, bottom 0.18s ease;
}

.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { bottom: 0; }

.site-header[data-open] .nav-toggle-bars::before { top: 4px; transform: rotate(45deg); }
.site-header[data-open] .nav-toggle-bars::after { bottom: 4px; transform: rotate(-45deg); }

/* ============================================================
   通用文本组件
   ============================================================ */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.26em;
  color: var(--color-accent);
}

.eyebrow::before {
  content: "";
  width: 18px;
  height: var(--border-thin);
  background: currentColor;
}

.section-head {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}

.lede {
  font-size: var(--text-lg);
  color: var(--color-ink-soft);
  max-width: var(--measure);
}

.side-marker {
  writing-mode: vertical-rl;
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.32em;
  color: var(--color-ink-muted);
}

.prose { max-width: var(--measure); }

.prose p { color: var(--color-ink-soft); margin-bottom: var(--space-4); }

.prose h2 { font-size: var(--text-2xl); margin-top: var(--space-8); }

.prose h3 { font-size: var(--text-xl); margin-top: var(--space-6); }

.prose ul, .prose ol { margin: 0 0 var(--space-4); padding-left: 1.2em; }

.prose ul li { list-style: square; margin-bottom: var(--space-1); color: var(--color-ink-soft); }

.prose ol li { list-style: decimal; margin-bottom: var(--space-1); color: var(--color-ink-soft); }

.prose blockquote {
  margin: var(--space-6) 0;
  padding: var(--space-3) var(--space-4);
  background: var(--color-highlight);
  border-radius: var(--radius-sm);
  color: var(--color-ink);
}

.prose blockquote p { color: var(--color-ink); margin: 0; max-width: none; }

/* ============================================================
   徽标与标签
   ============================================================ */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-soft);
  color: var(--color-primary);
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.tag--accent { background: var(--color-highlight); color: var(--color-accent); }

.tag--dark {
  background: color-mix(in srgb, var(--color-contrast-line) 78%, transparent);
  color: var(--color-contrast-accent);
}

.tag.is-active,
.tag[aria-pressed="true"] {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

/* ============================================================
   数字与指标
   ============================================================ */
.figure {
  font-family: var(--font-mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  color: var(--color-accent);
}

.figure--display { font-size: var(--text-figure); line-height: 1; }

.figure--lg { font-size: var(--text-2xl); line-height: 1.1; }

.figure--sm { font-size: var(--text-lg); line-height: 1.2; }

.figure-unit {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-ink-muted);
  margin-left: 4px;
}

.metric {
  padding: var(--space-4) var(--space-3);
  background: var(--color-surface-deep);
  border-radius: var(--radius-md);
}

.metric__key {
  display: block;
  margin-bottom: var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-ink-muted);
}

.metric__note {
  display: block;
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-ink-soft);
}

/* ============================================================
   编辑部目录行
   ============================================================ */
.index-row {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  padding: var(--space-3) 0;
  border-top: var(--border-thin) solid var(--color-line);
}

.index-row:last-child { border-bottom: var(--border-thin) solid var(--color-line); }

.index-row__no {
  flex: 0 0 auto;
  min-width: 2.6em;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-sm);
  color: var(--color-accent);
  font-variant-numeric: tabular-nums;
}

.index-row__main { flex: 1 1 auto; min-width: 0; }

.index-row__title {
  display: block;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.index-row__meta {
  display: block;
  margin-top: 6px;
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  letter-spacing: 0.04em;
}

/* ============================================================
   时间轴刻度
   ============================================================ */
.tick {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  transition: color 0.2s ease;
}

.tick__dot {
  flex: 0 0 auto;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-line);
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.tick.is-lit { color: var(--color-ink); }

.tick.is-lit .tick__dot { background: var(--color-primary); transform: scale(1.35); }

/* ============================================================
   图片容器
   ============================================================ */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--radius-md);
  background: var(--color-contrast-surface);
}

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

.media--hero { min-height: clamp(300px, 48vw, 560px); }

.media--short { min-height: clamp(180px, 24vw, 300px); }

.media__scrim {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}

.media__body {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: var(--space-4);
  color: var(--color-contrast-ink);
}

.media__body h2,
.media__body h3,
.media__body p { color: var(--color-contrast-ink); max-width: 42ch; }

.media__credit {
  position: absolute;
  right: var(--space-3);
  top: var(--space-3);
  writing-mode: vertical-rl;
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.28em;
  color: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent);
}

/* ============================================================
   深色反相区块
   ============================================================ */
.block-dark {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.block-dark h1,
.block-dark h2,
.block-dark h3,
.block-dark h4 { color: var(--color-contrast-ink); }

.block-dark p,
.block-dark li { color: color-mix(in srgb, var(--color-contrast-ink) 82%, transparent); }

.block-dark .eyebrow { color: var(--color-contrast-accent); }

.block-dark .side-marker { color: color-mix(in srgb, var(--color-contrast-ink) 58%, transparent); }

.block-dark .figure { color: var(--color-contrast-accent); }

.block-dark .figure-unit { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }

.block-dark .tag { background: color-mix(in srgb, var(--color-contrast-line) 78%, transparent); color: var(--color-contrast-accent); }

.block-dark .index-row { border-color: var(--color-contrast-line); }

.block-dark .index-row__title { color: var(--color-contrast-ink); }

.block-dark .index-row__no,
.block-dark .index-row__meta { color: var(--color-contrast-accent); }

.block-dark .metric { background: color-mix(in srgb, var(--color-contrast-line) 46%, transparent); }

.block-dark .metric__key,
.block-dark .metric__note { color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent); }

.block-dark .tick { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }

.block-dark .tick__dot { background: var(--color-contrast-line); }

.block-dark .tick.is-lit { color: var(--color-contrast-accent); }

.block-dark .tick.is-lit .tick__dot { background: var(--color-contrast-accent); }

.block-dark a { color: var(--color-contrast-ink); }

.block-dark a:hover { color: var(--color-contrast-accent); }

/* 分区滚动状态 */
[data-section] { transition: background-color 0.3s ease; }

[data-section][data-current] > .container > .section-head .eyebrow { opacity: 1; }

[data-section] > .container > .section-head .eyebrow { opacity: 0.62; }

/* ============================================================
   按钮
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.02em;
  text-decoration: none;
  transition: background-color 0.18s ease, color 0.18s ease, box-shadow 0.18s ease;
}

.btn--primary { background: var(--color-primary); color: var(--color-primary-ink); }

.btn--primary:hover { background: color-mix(in srgb, var(--color-primary) 82%, var(--color-ink)); }

.btn--accent { background: var(--color-accent); color: var(--color-accent-ink); }

.btn--accent:hover { background: var(--color-focus); }

.btn--ghost {
  background: transparent;
  color: var(--color-primary);
  box-shadow: inset 0 0 0 var(--border-thin) var(--color-primary);
}

.btn--ghost:hover { background: var(--color-primary-soft); }

.btn--onDark { background: var(--color-contrast-accent); color: var(--color-contrast-surface); }

.btn--onDark:hover { background: var(--color-highlight); }

.btn-row { display: flex; flex-wrap: wrap; gap: var(--space-2); }

/* ============================================================
   面包屑
   ============================================================ */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: var(--space-4);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

.breadcrumb li { display: flex; align-items: center; gap: 8px; }

.breadcrumb li + li::before { content: "/"; color: var(--color-line); }

.breadcrumb a { color: var(--color-ink-muted); }

.breadcrumb a:hover { color: var(--color-primary); }

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

/* ============================================================
   页脚：极简单行
   ============================================================ */
.site-footer {
  margin-top: var(--section-y);
  padding: var(--space-6) 0;
  background: var(--color-surface-alt);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-4);
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--space-3);
  font-size: var(--text-xs);
  letter-spacing: 0.02em;
  color: var(--color-ink-muted);
}

.footer-brand {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0;
  color: var(--color-ink);
}

.footer-sep {
  width: var(--border-thin);
  height: 14px;
  background: var(--color-line);
}

.footer-nav { display: flex; flex-wrap: wrap; gap: var(--space-2) var(--space-3); }

.footer-nav a {
  color: var(--color-ink-muted);
  border-bottom: var(--border-thin) solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.footer-nav a:hover { color: var(--color-primary); border-bottom-color: var(--color-primary); }

.footer-contact { display: inline-flex; align-items: center; gap: 8px; color: var(--color-ink-soft); }

.footer-dot { color: var(--color-line); }

.footer-icp { color: var(--color-ink-muted); }

.footer-copy { color: var(--color-ink-muted); }

.footer-round {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  background: var(--color-highlight);
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-xs);
  letter-spacing: 0;
  transform: rotate(-1.4deg);
}

/* ============================================================
   显现动效
   ============================================================ */
[data-reveal] {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

[data-reveal].is-visible { opacity: 1; transform: none; }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1180px) {
  .nav-list a { padding: 8px 10px; }
}

@media (max-width: 1080px) {
  .vmark { display: none; }
}

@media (max-width: 1024px) {
  .col-3, .col-4, .col-5 { grid-column: span 6; }
  .col-7, .col-8, .col-9 { grid-column: span 12; }
}

@media (max-width: 960px) {
  .site-header { padding: var(--space-1) var(--space-2) 0; }

  .header-inner { gap: var(--space-2); }

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

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: calc(100% + var(--space-1));
    display: none;
    padding: var(--space-2);
    background: var(--color-surface);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-2);
    justify-content: flex-start;
    max-height: calc(100vh - 140px);
    overflow-y: auto;
  }

  .site-nav[data-open],
  .site-header[data-open] .site-nav { display: block; }

  .nav-list { flex-direction: column; align-items: stretch; gap: 2px; }

  .nav-list a { padding: 12px 14px; font-size: var(--text-base); }

  .round-value { display: none; }

  .round-toggle { padding: 8px 10px; }

  .round-menu { min-width: 210px; }
}

@media (max-width: 760px) {
  .section { padding: calc(var(--section-y) * 0.6) 0; }
  .section--lg { padding: calc(var(--section-y-lg) * 0.6) 0; }

  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9 { grid-column: span 12; }

  .grid--loose { gap: var(--space-4); }

  .lede { font-size: var(--text-base); }

  .index-row { flex-wrap: wrap; gap: var(--space-1) var(--space-2); }

  .footer-inner { gap: var(--space-2) var(--space-3); }

  .footer-sep { display: none; }

  .footer-round { margin-left: 0; }

  .media__body { padding: var(--space-3); }
}

@media (max-width: 520px) {
  .brand-sub { display: none; }
  .round-key { display: none; }
  .skip-link { left: var(--space-2); }
}

/* ============================================================
   reduced motion
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  [data-reveal] { opacity: 1; transform: none; }

  .scroll-progress__bar { transition: none; }

  .footer-round { transform: none; }
}