/* ==========================================================================
   大发168安装 · 共享样式 /assets/site.css
   暖纸与深墨体系 · 精密网格 · 纵向长卷
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: clamp(96px, 14vh, 148px);
}

body { margin: 0; }

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

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

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

a { color: inherit; }

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

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

input, textarea, select { font: inherit; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  /* 色 */
  --ink-900: #0C1F2E;
  --ink-700: #16394F;
  --paper-100: #F5EFE4;
  --paper-300: #E7DCC9;
  --brass-500: #B87A3D;
  --brass-200: #E3C39A;
  --signal: #E0572A;
  --celadon: #3A7869;
  --ink-black: #14181B;
  --line: #C9BFAE;

  /* 字体 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC",
    sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Roboto Mono", "Courier New", monospace;

  /* 度量 */
  --wrap: 1180px;
  --wrap-narrow: 760px;
  --gutter: clamp(16px, 4vw, 40px);
  --space: clamp(36px, 6vw, 88px);
  --line-hair: 1px;

  /* 动效 */
  --dur: 180ms;
  --ease: cubic-bezier(.2, .7, .3, 1);
}

/* ---------- 3. 中文排版与页面底纹 ---------- */
body {
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.75;
  font-weight: 400;
  color: var(--ink-black);
  background-color: var(--paper-100);
  background-image:
    linear-gradient(to right, rgba(201, 191, 174, .13) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(201, 191, 174, .13) 1px, transparent 1px);
  background-size: 24px 24px;
  background-position: -1px -1px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

p { line-height: 1.75; }

strong, b { font-weight: 700; }

::selection {
  background: var(--brass-200);
  color: var(--ink-900);
}

#main-content {
  display: block;
  outline: none;
}

/* ---------- 4. 焦点与无障碍 ---------- */
:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
}

.site-header :focus-visible,
.site-footer :focus-visible {
  outline-color: var(--brass-200);
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -120px;
  z-index: 300;
  display: inline-block;
  padding: 10px 18px;
  background: var(--brass-200);
  color: var(--ink-900);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .04em;
  text-decoration: none;
  transition: top var(--dur) var(--ease);
}

.skip-link:focus {
  top: 12px;
}

/* ---------- 5. 容器与网格 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.wrap--narrow {
  max-width: var(--wrap-narrow);
}

.grid {
  display: grid;
  gap: clamp(20px, 3vw, 40px);
  align-items: start;
}

.grid--7-5 { grid-template-columns: 7fr 5fr; }
.grid--5-7 { grid-template-columns: 5fr 7fr; }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid var(--brass-500);
  border-radius: 0;
  background: transparent;
  color: var(--brass-200);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: .06em;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color var(--dur) var(--ease),
    color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.btn--brass {
  background: var(--brass-500);
  border-color: var(--brass-500);
  color: var(--ink-900);
  font-weight: 600;
}

.btn--brass:hover,
.btn--brass:focus-visible {
  background: var(--brass-200);
  border-color: var(--brass-200);
  color: var(--ink-900);
}

.btn--ghost {
  background: transparent;
  border-color: rgba(227, 195, 154, .5);
  color: var(--paper-100);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  background: var(--ink-700);
  border-color: var(--brass-500);
  color: var(--paper-100);
}

.btn--signal {
  background: var(--signal);
  border-color: var(--signal);
  color: #FFFFFF;
  font-weight: 600;
}

.btn--signal:hover,
.btn--signal:focus-visible {
  background: var(--brass-500);
  border-color: var(--brass-500);
  color: var(--ink-900);
}

/* ---------- 7. 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  isolation: isolate;
  background: var(--ink-900);
  color: var(--paper-100);
  box-shadow: 0 1px 0 rgba(12, 31, 46, .16);
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image: radial-gradient(rgba(227, 195, 154, .16) 1px, transparent 1px);
  background-size: 9px 9px;
  opacity: .5;
  -webkit-mask-image: linear-gradient(100deg, transparent 26%, #000 76%);
  mask-image: linear-gradient(100deg, transparent 26%, #000 76%);
}

.site-header__rule {
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--brass-500) 0%,
    var(--brass-500) 32%,
    var(--signal) 32%,
    var(--signal) 40%,
    var(--ink-700) 40%,
    var(--ink-700) 100%
  );
}

.site-header__progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 3;
  height: 2px;
  background: var(--signal);
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
  will-change: transform;
}

.site-header__inner {
  position: relative;
}

/* 刊头 */
.masthead {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 12px;
  padding-block: clamp(14px, 2vw, 22px);
  border-bottom: var(--line-hair) solid rgba(201, 191, 174, .22);
}

.masthead__utility {
  justify-self: start;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  line-height: 1.6;
  color: var(--brass-200);
  white-space: nowrap;
}

.masthead__lockup {
  justify-self: center;
  text-align: center;
  min-width: 0;
}

.masthead__brand {
  display: inline-block;
  font-size: clamp(24px, 3.4vw, 38px);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--paper-100);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.masthead__brand:hover,
.masthead__brand:focus-visible {
  color: var(--brass-200);
}

.masthead__descriptor {
  display: block;
  margin-top: 7px;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .26em;
  line-height: 1.6;
  color: var(--brass-500);
}

.masthead__actions {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 12px;
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 0 10px;
  min-width: 44px;
  height: 40px;
  border: var(--line-hair) solid rgba(227, 195, 154, .5);
  background: transparent;
  color: var(--brass-200);
  transition: border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.nav-toggle:hover,
.nav-toggle:focus-visible {
  border-color: var(--brass-200);
  background: var(--ink-700);
}

.nav-toggle__bars {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 18px;
  height: 14px;
}

.nav-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.nav-toggle__text {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
}

/* 主导航 */
.site-nav {
  position: relative;
  z-index: 2;
  display: flex;
  justify-content: center;
}

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: clamp(2px, 1.6vw, 26px);
}

.site-nav__item {
  display: flex;
}

.site-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 7px;
  padding: 13px 6px 12px;
  font-size: 13.5px;
  font-weight: 500;
  letter-spacing: .08em;
  line-height: 1.5;
  color: rgba(245, 239, 228, .82);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 6px;
  right: 6px;
  bottom: 7px;
  height: 1px;
  background: var(--signal);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.site-nav__link:hover,
.site-nav__link:focus-visible {
  color: var(--paper-100);
}

.site-nav__link:hover::after,
.site-nav__link:focus-visible::after {
  transform: scaleX(1);
}

.site-nav__link[aria-current="page"] {
  color: var(--brass-200);
}

.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--signal);
}

.site-nav__num {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .06em;
  color: var(--brass-500);
  transition: color var(--dur) var(--ease);
}

.site-nav__link:hover .site-nav__num,
.site-nav__link:focus-visible .site-nav__num,
.site-nav__link[aria-current="page"] .site-nav__num {
  color: var(--signal);
}

.site-nav__label {
  display: inline-block;
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: 0;
  background: var(--ink-900);
  color: var(--paper-100);
  border-top: 3px solid var(--brass-500);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: radial-gradient(rgba(227, 195, 154, .14) 1px, transparent 1px);
  background-size: 12px 12px;
  -webkit-mask-image: radial-gradient(120% 82% at 82% 0%, #000 0%, transparent 62%);
  mask-image: radial-gradient(120% 82% at 82% 0%, #000 0%, transparent 62%);
}

.site-footer .wrap {
  position: relative;
  z-index: 1;
}

.footer__top {
  padding-block: clamp(36px, 5vw, 64px) clamp(22px, 3vw, 34px);
}

.footer__eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .26em;
  line-height: 1.6;
  color: var(--brass-500);
}

.footer__brand-line {
  margin-top: 12px;
  max-width: 26ch;
  font-size: clamp(19px, 2.6vw, 28px);
  font-weight: 900;
  line-height: 1.35;
  letter-spacing: -.01em;
  color: var(--paper-100);
}

.footer__grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(18px, 2.6vw, 36px);
  margin-top: clamp(26px, 4vw, 44px);
}

.footer__col {
  min-width: 0;
}

.footer__col-title {
  display: inline-block;
  padding-bottom: 8px;
  border-bottom: var(--line-hair) solid rgba(227, 195, 154, .32);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .12em;
  color: var(--brass-200);
  text-decoration: none;
  transition: color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.footer__col-title:hover,
.footer__col-title:focus-visible {
  color: var(--paper-100);
  border-bottom-color: var(--signal);
}

.footer__list {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}

.footer__link {
  display: inline-block;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(245, 239, 228, .72);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.footer__link:hover,
.footer__link:focus-visible {
  color: var(--brass-200);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer__contact {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(16px, 2.6vw, 32px);
  margin-top: clamp(28px, 4vw, 44px);
  padding-top: clamp(20px, 3vw, 28px);
  border-top: var(--line-hair) solid rgba(201, 191, 174, .22);
}

.footer__contact-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 10px;
  min-width: 0;
}

.footer__contact-label {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .22em;
  line-height: 1.6;
  color: var(--brass-500);
}

.footer__contact-value {
  font-size: 15px;
  line-height: 1.6;
  color: var(--paper-100);
  word-break: break-word;
}

.copy-btn {
  padding: 3px 9px;
  border: var(--line-hair) solid rgba(227, 195, 154, .42);
  background: transparent;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  line-height: 1.5;
  color: var(--brass-200);
  transition: background-color var(--dur) var(--ease),
    color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.copy-btn:hover,
.copy-btn:focus-visible {
  background: var(--brass-200);
  border-color: var(--brass-200);
  color: var(--ink-900);
}

.copy-btn[data-copied] {
  background: var(--celadon);
  border-color: var(--celadon);
  color: var(--paper-100);
}

.footer__note {
  grid-column: 1 / -1;
  max-width: 58ch;
  font-size: 13px;
  line-height: 1.75;
  color: rgba(245, 239, 228, .58);
}

.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-block: 18px;
  border-top: var(--line-hair) solid rgba(201, 191, 174, .22);
}

.footer__legal {
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .04em;
  color: rgba(245, 239, 228, .6);
}

.footer__legal-list {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 12px;
  line-height: 1.7;
}

.footer__legal-link {
  color: rgba(245, 239, 228, .72);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.footer__legal-link:hover,
.footer__legal-link:focus-visible {
  color: var(--brass-200);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 9. 章节与区块 ---------- */
.section {
  padding-block: clamp(36px, 6vw, 72px);
}

.section--band {
  background: var(--ink-900);
  color: var(--paper-100);
}

.section--paper {
  background: var(--paper-300);
}

.band {
  padding-block: clamp(28px, 4vw, 48px);
  background: var(--ink-900);
  color: var(--paper-100);
}

.chapter {
  padding-block: clamp(36px, 6vw, 72px);
  border-top: var(--line-hair) solid var(--line);
}

.chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(14px, 2.5vw, 28px);
  align-items: start;
  margin-bottom: clamp(20px, 3vw, 36px);
}

.chapter__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.6vw, 42px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--brass-500);
}

.chapter__title {
  font-size: clamp(24px, 3.4vw, 40px);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -.02em;
  color: var(--ink-900);
}

.chapter__lede {
  margin-top: 10px;
  max-width: 38em;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink-700);
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .24em;
  line-height: 1.6;
  color: var(--brass-500);
}

.annotation {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .24em;
  line-height: 1.4;
  color: var(--brass-500);
}

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

.num {
  font-family: var(--font-mono);
  letter-spacing: .02em;
  font-variant-numeric: tabular-nums;
}

/* ---------- 10. 卡片与数字 ---------- */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 26px);
  border: var(--line-hair) solid var(--line);
  background: var(--paper-100);
  transition: border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.card:hover,
.card:focus-within {
  border-color: var(--brass-500);
  background: var(--paper-300);
}

.card__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  line-height: 1.6;
  color: var(--ink-700);
}

.card__value {
  display: block;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -.01em;
  color: var(--ink-900);
  font-variant-numeric: tabular-nums;
}

.card__note {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-700);
}

.card--accent {
  border-top: 4px solid var(--brass-500);
}

.card--price {
  padding-top: calc(clamp(18px, 2.4vw, 26px) + 6px);
}

.card--price::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: var(--accent, var(--brass-500));
}

.stat {
  display: grid;
  gap: 6px;
}

.stat__num {
  font-family: var(--font-mono);
  font-size: clamp(34px, 5vw, 56px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--brass-500);
  font-variant-numeric: tabular-nums;
}

.stat__label {
  font-size: 13px;
  letter-spacing: .08em;
  line-height: 1.6;
  color: var(--ink-700);
}

/* ---------- 11. 图版容器（页面阶段投放图片） ---------- */
.figure {
  position: relative;
  margin: 0;
  border: var(--line-hair) solid var(--ink-900);
  background: var(--paper-300);
}

.figure__frame {
  position: relative;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: var(--ink-700);
}

.figure__img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure__tag {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 1;
  padding: 4px 10px;
  background: var(--ink-900);
  color: var(--brass-200);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  line-height: 1.6;
}

.figure__caption {
  padding: 10px 14px;
  border-top: var(--line-hair) solid var(--line);
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink-700);
}

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

/* ---------- 12. 表格与标签 ---------- */
.data-table {
  width: 100%;
  font-size: 15px;
  line-height: 1.65;
}

.data-table caption {
  caption-side: top;
  padding-bottom: 10px;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--brass-500);
}

.data-table th {
  padding: 10px 12px;
  background: var(--ink-700);
  color: var(--paper-100);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .08em;
  text-align: left;
}

.data-table td {
  padding: 10px 12px;
  border-bottom: var(--line-hair) solid var(--line);
  vertical-align: top;
}

.data-table tbody tr:nth-child(even) {
  background: var(--paper-300);
}

.tag {
  display: inline-block;
  padding: 2px 8px;
  border: var(--line-hair) solid currentColor;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  line-height: 1.6;
}

.tag--brass { color: var(--brass-500); }
.tag--green { color: var(--celadon); }
.tag--orange { color: var(--signal); }

/* ---------- 13. 面包屑 ---------- */
.breadcrumb {
  padding-block: 16px;
  border-bottom: var(--line-hair) solid var(--line);
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-700);
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 8px;
}

.breadcrumb__list > li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--brass-500);
}

.breadcrumb__link {
  color: var(--ink-700);
  text-decoration: none;
  border-bottom: var(--line-hair) solid transparent;
  transition: color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.breadcrumb__link:hover,
.breadcrumb__link:focus-visible {
  color: var(--brass-500);
  border-bottom-color: var(--brass-500);
}

/* ---------- 14. 正文排版 ---------- */
.prose {
  max-width: 38em;
  font-size: 17px;
  line-height: 1.75;
}

.prose > * + * {
  margin-top: 1em;
}

.prose h2 {
  margin-top: 1.8em;
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 800;
  line-height: 1.4;
  letter-spacing: -.01em;
  color: var(--ink-900);
}

.prose h3 {
  margin-top: 1.4em;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink-900);
}

.prose ul {
  display: grid;
  gap: 8px;
}

.prose ul > li {
  position: relative;
  padding-left: 20px;
}

.prose ul > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 9px;
  height: 1px;
  background: var(--brass-500);
}

.prose a {
  color: var(--ink-700);
  text-decoration: none;
  border-bottom: var(--line-hair) solid var(--brass-500);
  transition: color var(--dur) var(--ease);
}

.prose a:hover,
.prose a:focus-visible {
  color: var(--brass-500);
}

/* ---------- 15. 响应式 ---------- */
@media (max-width: 1080px) {
  .site-nav__list { gap: clamp(2px, 1vw, 14px); }
  .site-nav__link { font-size: 13px; letter-spacing: .04em; }
}

@media (max-width: 900px) {
  .site-nav__list { flex-wrap: wrap; }

  .grid--7-5,
  .grid--5-7,
  .grid--12 {
    grid-template-columns: minmax(0, 1fr);
  }

  .masthead__cta { display: none; }

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

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: block;
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    opacity: 0;
    background: var(--ink-900);
    border-top: var(--line-hair) solid rgba(201, 191, 174, .22);
    transition: max-height .22s var(--ease),
      opacity .18s var(--ease),
      visibility 0s linear .22s;
  }

  .site-nav[data-open] {
    max-height: 76vh;
    overflow-y: auto;
    visibility: visible;
    opacity: 1;
    transition: max-height .22s var(--ease),
      opacity .18s var(--ease),
      visibility 0s linear 0s;
  }

  .site-nav__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
    padding: 6px var(--gutter) 20px;
  }

  .site-nav__item {
    border-bottom: var(--line-hair) solid rgba(201, 191, 174, .16);
  }

  .site-nav__item:last-child { border-bottom: 0; }

  .site-nav__link {
    padding: 15px 4px;
    font-size: 15px;
    letter-spacing: .1em;
  }

  .site-nav__link::after { display: none; }

  .site-nav__link[aria-current="page"] {
    box-shadow: inset 2px 0 0 var(--signal);
  }

  .site-nav__num { font-size: 11px; }

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

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

@media (max-width: 620px) {
  body { font-size: 16px; line-height: 1.78; }

  .masthead__utility { display: none; }

  .masthead__descriptor { letter-spacing: .18em; }

  .footer__grid { grid-template-columns: minmax(0, 1fr); }
  .footer__contact { grid-template-columns: minmax(0, 1fr); }

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

  .chapter__head {
    grid-template-columns: minmax(0, 1fr);
    gap: 10px;
  }

  .data-table { font-size: 14px; }
  .data-table th,
  .data-table td { padding: 8px 10px; }
}

@media (max-width: 380px) {
  .masthead__brand { font-size: 22px; }
  .nav-toggle { padding: 0 8px; }
  .nav-toggle__text { display: none; }
}

/* ---------- 16. 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0ms !important;
    scroll-behavior: auto !important;
  }

  .site-nav__link::after { transform: scaleX(1); opacity: .85; }
  .site-nav__link:hover::after { transform: scaleX(1); }
}