/* ==========================================================================
   金沙平台中心 · 共享样式表  /assets/site.css
   包含：reset / 变量 / 中文排版 / 刊头 / 导航 / 页脚 / 通用组件 / 响应式
   ========================================================================== */

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

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

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

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

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

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

button {
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

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

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

/* ---------- 2. 设计变量 ---------- */
:root {
  --sand: #F5EEE2;
  --paper: #FDFAF4;
  --ink: #1E1B18;
  --ink-2: #4A443D;
  --gold: #C4882B;
  --gold-deep: #8E5F1C;
  --river: #2C6A66;
  --night: #103B39;
  --cinnabar: #D0503A;
  --dune: #E0CDB4;
  --mist: #B9B2A6;

  --font-serif: "Source Han Serif SC", "Noto Serif SC", "Songti SC", "STSong", "SimSun", Georgia, serif;
  --font-sans: "Source Han Sans SC", "HarmonyOS Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", "SFMono-Regular", Menlo, Consolas, monospace;

  --wrap: 1180px;
  --wrap-narrow: 780px;
  --gutter: clamp(1.2rem, 3.2vw, 2.4rem);

  --ease: cubic-bezier(.22, .61, .36, 1);
  --dur: 200ms;

  --density-size: 17px;
  --density-line: 1.85;
}

html[data-density="compact"] {
  --density-size: 15.5px;
  --density-line: 1.68;
}

/* ---------- 3. 基础与中文排版 ---------- */
html {
  scroll-behavior: smooth;
  scroll-padding-top: 9rem;
}

body {
  background: var(--sand);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: var(--density-size);
  line-height: var(--density-line);
  font-weight: 400;
  letter-spacing: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-underline-offset: .22em;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 600;
  letter-spacing: .02em;
  line-height: 1.22;
  text-wrap: balance;
}

p { text-wrap: pretty; }

:focus-visible {
  outline: 2px solid var(--gold-deep);
  outline-offset: 2px;
}

/* ---------- 4. 布局容器 ---------- */
.wrap {
  width: min(100% - var(--gutter) * 2, var(--wrap));
  margin-inline: auto;
}

.wrap--narrow {
  width: min(100% - var(--gutter) * 2, var(--wrap-narrow));
  margin-inline: auto;
}

.rule {
  height: 1px;
  border: 0;
  background: var(--dune);
  margin: clamp(1.6rem, 3vw, 2.6rem) 0;
}

/* ---------- 5. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  left: 1rem;
  top: -5rem;
  z-index: 90;
  background: var(--ink);
  color: var(--paper);
  padding: .6rem 1.1rem;
  font-size: .85rem;
  letter-spacing: .08em;
  transition: top var(--dur) var(--ease);
}

.skip-link:focus {
  top: .75rem;
}

/* ---------- 6. 刊头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--sand);
  border-top: 1px solid var(--dune);
  border-bottom: 1px solid var(--dune);
}

.masthead {
  width: min(100% - var(--gutter) * 2, var(--wrap));
  margin-inline: auto;
  display: grid;
  grid-template-areas: "flag lockup tools";
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 1rem;
  padding: clamp(.9rem, 1.8vw, 1.4rem) 0 clamp(.7rem, 1.4vw, 1rem);
}

.masthead__flag {
  grid-area: flag;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  color: var(--ink-2);
  text-transform: uppercase;
}

.masthead__lockup {
  grid-area: lockup;
  text-align: center;
}

.masthead__brand {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3.4vw, 2.5rem);
  line-height: 1.12;
  letter-spacing: .06em;
  font-weight: 600;
  color: var(--ink);
}

.masthead__brandlink {
  border-bottom: 2px solid transparent;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.masthead__brandlink:hover,
.masthead__brandlink:focus-visible {
  border-bottom-color: var(--gold);
}

.masthead__section {
  margin-top: .35rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .24em;
  color: var(--gold-deep);
  text-transform: uppercase;
}

.masthead__tools {
  grid-area: tools;
  justify-self: end;
  display: flex;
  align-items: center;
  gap: clamp(.6rem, 1.4vw, 1.15rem);
}

.masthead__action {
  font-size: .86rem;
  letter-spacing: .06em;
  color: var(--gold-deep);
  padding-bottom: 2px;
  border-bottom: 1px solid var(--gold-deep);
  white-space: nowrap;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.masthead__action:hover,
.masthead__action:focus-visible {
  color: var(--ink);
  border-bottom-color: var(--ink);
}

.density-toggle {
  display: inline-flex;
  align-items: center;
  padding: .42rem .7rem;
  border: 1px solid var(--mist);
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .1em;
  color: var(--ink-2);
  white-space: nowrap;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.density-toggle:hover {
  border-color: var(--gold);
  color: var(--gold-deep);
}

.density-toggle[aria-pressed="true"] {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

.density-toggle__label { line-height: 1; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: .55rem;
  padding: .5rem .85rem;
  border: 1px solid var(--ink-2);
  font-size: .82rem;
  letter-spacing: .1em;
  color: var(--ink);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.nav-toggle:hover {
  border-color: var(--gold);
  color: var(--gold-deep);
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  flex: none;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.nav-toggle__bars::before { top: -5px; }
.nav-toggle__bars::after { top: 5px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-5px) rotate(-45deg); }

.nav-toggle__text { line-height: 1; }

/* ---------- 7. 居中栏目导航 ---------- */
.site-nav {
  background: var(--sand);
  border-top: 1px solid var(--dune);
}

.site-nav__list {
  width: min(100% - var(--gutter) * 2, var(--wrap));
  margin-inline: auto;
  display: flex;
  justify-content: center;
  align-items: stretch;
  gap: clamp(.5rem, 2.4vw, 2.4rem);
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.site-nav__list::-webkit-scrollbar { display: none; }

.site-nav__item { flex: none; }

.site-nav__link {
  display: block;
  position: relative;
  padding: .85rem .15rem;
  font-size: .95rem;
  letter-spacing: .06em;
  color: var(--ink-2);
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.site-nav__link:hover {
  color: var(--ink);
  border-bottom-color: var(--gold);
}

.site-nav__link:focus-visible {
  color: var(--ink);
  border-bottom-color: var(--gold-deep);
}

.site-nav__link[aria-current="page"] {
  color: var(--ink);
  font-weight: 600;
  border-bottom-color: var(--gold);
}

/* ---------- 8. 滚动进度线 ---------- */
.site-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left center;
  opacity: 0;
  transition: opacity var(--dur) var(--ease);
  pointer-events: none;
}

/* ---------- 9. 页脚 ---------- */
.site-footer {
  margin-top: clamp(3rem, 7vw, 6.5rem);
  background: var(--night);
  color: var(--paper);
  border-top: 4px solid var(--gold);
}

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

.site-footer__inner {
  width: min(100% - var(--gutter) * 2, var(--wrap));
  margin-inline: auto;
  display: grid;
  grid-template-columns: 1.35fr 1fr 1fr 1.7fr;
  gap: clamp(1.6rem, 3.5vw, 3rem);
  padding: clamp(2.4rem, 5vw, 4rem) 0 clamp(1.8rem, 3vw, 2.6rem);
}

.site-footer__brandcol {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: .7rem;
}

.site-footer__brand {
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 2.6vw, 1.9rem);
  letter-spacing: .06em;
  line-height: 1.2;
  color: var(--paper);
}

.site-footer__brandline {
  font-size: .92rem;
  letter-spacing: .12em;
  color: var(--dune);
}

.site-footer__col {
  display: block;
}

.site-footer__coltitle {
  font-family: var(--font-mono);
  font-size: .7rem;
  font-weight: 400;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--gold);
  padding-bottom: .55rem;
  margin-bottom: .85rem;
  border-bottom: 1px solid rgba(253, 250, 244, .18);
}

.site-footer__list {
  display: flex;
  flex-direction: column;
  gap: .35rem;
}

.site-footer__list--plain {
  gap: .7rem;
}

.site-footer__link {
  display: inline-block;
  font-size: .95rem;
  color: rgba(253, 250, 244, .82);
  padding-bottom: 1px;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.site-footer__link:hover,
.site-footer__link:focus-visible {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

.site-footer__link--lead {
  margin-top: .35rem;
  color: var(--dune);
  letter-spacing: .06em;
  border-bottom-color: rgba(224, 205, 180, .4);
}

.site-footer__fact {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .4rem .55rem;
  font-size: .9rem;
  line-height: 1.7;
}

.site-footer__fact--wide {
  align-items: flex-start;
}

.site-footer__key {
  flex: none;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .12em;
  color: var(--dune);
  min-width: 4.6em;
}

.site-footer__val {
  color: rgba(253, 250, 244, .92);
  word-break: break-word;
  flex: 1 1 10rem;
}

.copy-btn {
  flex: none;
  padding: .12rem .5rem;
  border: 1px solid rgba(224, 205, 180, .5);
  font-family: var(--font-mono);
  font-size: .66rem;
  letter-spacing: .1em;
  color: var(--dune);
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.copy-btn:hover {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
}

.copy-btn[data-copied] {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
}

.site-footer__legal {
  border-top: 1px solid rgba(253, 250, 244, .16);
}

.site-footer__legalinner {
  width: min(100% - var(--gutter) * 2, var(--wrap));
  margin-inline: auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .6rem 1.4rem;
  padding: 1.1rem 0 1.5rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .08em;
  color: var(--mist);
}

.site-footer__icp,
.site-footer__closing,
.site-footer__copyright {
  line-height: 1.7;
}

.site-footer__closing {
  color: rgba(253, 250, 244, .72);
}

/* ---------- 10. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .75rem 1.4rem;
  border: 1px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  font-size: .92rem;
  letter-spacing: .06em;
  line-height: 1.3;
  transition: transform var(--dur) var(--ease), background-color var(--dur) var(--ease),
              color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.btn:hover {
  transform: translateY(-3px);
  border-color: var(--gold);
}

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

.btn--gold:hover {
  background: var(--gold-deep);
  border-color: var(--gold-deep);
  color: var(--paper);
}

.btn--ghost {
  background: transparent;
  border-color: var(--ink-2);
  color: var(--ink);
}

.btn--ghost:hover {
  border-color: var(--gold-deep);
  color: var(--gold-deep);
}

.btn--cinnabar {
  background: var(--cinnabar);
  border-color: var(--cinnabar);
  color: var(--paper);
}

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

.btn--quiet {
  padding: .25rem 0;
  border: 0;
  border-bottom: 1px solid var(--gold-deep);
  background: none;
  color: var(--gold-deep);
  border-radius: 0;
}

.btn--quiet:hover {
  transform: none;
  color: var(--ink);
  border-bottom-color: var(--ink);
}

/* ---------- 11. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .45rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  color: var(--ink-2);
  margin-bottom: 1.4rem;
}

.breadcrumb a {
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.breadcrumb a:hover,
.breadcrumb a:focus-visible {
  color: var(--gold-deep);
  border-bottom-color: var(--gold-deep);
}

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

/* ---------- 12. 正文与章节 ---------- */
.prose {
  max-width: 38em;
}

.prose > * + * { margin-top: 1.15em; }

.prose h2,
.prose h3 {
  font-family: var(--font-serif);
  line-height: 1.3;
  margin-top: 1.9em;
}

.prose h2 { font-size: clamp(1.45rem, 2.6vw, 1.95rem); }
.prose h3 { font-size: clamp(1.12rem, 2vw, 1.35rem); }

.prose ul,
.prose ol {
  list-style: square;
  padding-left: 1.35em;
}

.prose ol { list-style: decimal; }
.prose li + li { margin-top: .4em; }

.prose strong { font-weight: 600; }

.prose a {
  color: var(--gold-deep);
  border-bottom: 1px solid var(--dune);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.prose a:hover,
.prose a:focus-visible {
  color: var(--ink);
  border-bottom-color: var(--gold);
}

.section-head {
  display: grid;
  gap: .55rem;
  margin-bottom: clamp(1.2rem, 2.4vw, 2rem);
}

.section-head__title {
  font-size: clamp(1.7rem, 3.4vw, 2.4rem);
  line-height: 1.22;
}

.section-head__note {
  font-size: .96rem;
  color: var(--ink-2);
  max-width: 36em;
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--gold-deep);
}

.quote {
  font-family: var(--font-serif);
  font-size: clamp(1.25rem, 2.6vw, 1.8rem);
  line-height: 1.55;
  letter-spacing: .01em;
  color: var(--ink);
  border-left: 3px solid var(--gold);
  padding-left: clamp(1rem, 2vw, 1.6rem);
}

/* ---------- 13. 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(1rem, 2.4vw, 1.8rem);
}

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

/* ---------- 14. 长条卡（江面延展） ---------- */
.ledger {
  position: relative;
  display: block;
  background: var(--paper);
  border: 1px solid var(--dune);
  padding: clamp(1.2rem, 2.4vw, 1.8rem) clamp(1.3rem, 2.6vw, 2rem) clamp(1.2rem, 2.4vw, 1.8rem) clamp(1.6rem, 3vw, 2.4rem);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.ledger::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 5px;
  background: var(--gold);
  transition: width var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.ledger:hover,
.ledger:focus-visible {
  transform: translateY(-3px);
  border-color: var(--gold);
}

.ledger:hover::before,
.ledger:focus-visible::before {
  width: 12px;
}

.ledger__index {
  display: block;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .16em;
  color: var(--gold-deep);
  margin-bottom: .45rem;
}

.ledger__title {
  font-family: var(--font-serif);
  font-size: clamp(1.15rem, 2.2vw, 1.5rem);
  line-height: 1.35;
  letter-spacing: .01em;
  margin-bottom: .4rem;
}

.ledger__body {
  font-size: .96rem;
  color: var(--ink-2);
  max-width: 48em;
}

.ledger__meta {
  margin-top: .8rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .12em;
  color: var(--mist);
}

/* ---------- 15. 纸面卡片 ---------- */
.card {
  display: block;
  background: var(--paper);
  border: 1px solid var(--dune);
  padding: clamp(1.1rem, 2.2vw, 1.6rem);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.card:hover,
.card:focus-visible {
  transform: translateY(-3px);
  border-color: var(--gold);
}

.card__title {
  font-family: var(--font-serif);
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
  line-height: 1.36;
  margin-bottom: .5rem;
}

.card__meta {
  margin-top: .8rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .12em;
  color: var(--ink-2);
}

/* ---------- 16. 标签 ---------- */
.tag {
  display: inline-block;
  background: var(--paper);
  border: 1px solid var(--dune);
  padding: .18rem .55rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .12em;
  line-height: 1.7;
  text-transform: uppercase;
  color: var(--gold-deep);
}

/* ---------- 17. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--dune);
  border: 1px solid var(--dune);
  width: 100%;
}

.media-frame__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: sepia(.08) saturate(.94);
}

.media-frame__caption {
  margin-top: .6rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .1em;
  color: var(--ink-2);
}

.media-frame[data-placeholder] {
  aspect-ratio: 5 / 2;
}

.media-frame[data-placeholder]::after {
  content: attr(data-placeholder);
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  text-align: center;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .16em;
  color: var(--ink-2);
  opacity: .6;
}

.media-frame--wide { aspect-ratio: 5 / 2; }
.media-frame--equal { aspect-ratio: 16 / 9; }
.media-frame--portrait { aspect-ratio: 3 / 4; }
.media-frame--tall { aspect-ratio: 2 / 3; }

/* ---------- 18. 滚动显现 ---------- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 520ms var(--ease), transform 520ms var(--ease);
  will-change: opacity, transform;
}

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

/* ---------- 19. 响应式 ---------- */
@media (max-width: 1080px) {
  .site-footer__inner {
    grid-template-columns: 1.2fr 1fr 1fr;
  }
  .site-footer__col--contact {
    grid-column: 1 / -1;
  }
}

@media (max-width: 860px) {
  .masthead {
    grid-template-areas:
      "lockup"
      "flag"
      "tools";
    grid-template-columns: minmax(0, 1fr);
    justify-items: center;
    text-align: center;
    gap: .55rem;
    padding-top: 1rem;
  }

  .masthead__flag {
    order: 2;
    font-size: .68rem;
    letter-spacing: .14em;
  }

  .masthead__tools {
    grid-area: tools;
    justify-self: center;
    flex-wrap: wrap;
    justify-content: center;
    gap: .6rem;
  }

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

  .site-nav {
    max-height: 0;
    overflow: hidden;
    border-top-color: transparent;
    transition: max-height 280ms var(--ease), border-color var(--dur) var(--ease);
  }

  .site-nav[data-open] {
    max-height: min(72vh, 32rem);
    overflow-y: auto;
    border-top-color: var(--dune);
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    padding-bottom: .5rem;
  }

  .site-nav__link {
    border-bottom: 1px solid var(--dune);
    padding: .9rem .2rem;
    font-size: 1rem;
  }

  .site-nav__link[aria-current="page"] {
    border-bottom-color: var(--gold);
  }

  html { scroll-padding-top: 12rem; }
}

@media (max-width: 900px) {
  .grid--3,
  .grid--4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 680px) {
  .site-footer__inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 1.8rem;
  }

  .site-footer__col--contact {
    grid-column: auto;
  }

  .site-footer__legalinner {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-footer__key { min-width: 0; }

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

  .density-toggle { display: none; }
}

@media (max-width: 420px) {
  .masthead__brand { letter-spacing: .04em; }
  .masthead__section { letter-spacing: .16em; }
}

/* ---------- 20. 动效偏好与降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }

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

  .btn:hover,
  .card:hover,
  .ledger:hover,
  .ledger:focus-visible {
    transform: none;
  }
}

@media (scripting: none) {
  html [data-reveal] {
    opacity: 1;
    transform: none;
  }
}