/* ============================================================
   云开赛场 GOAL KAIYUN — 共享站点样式 /assets/site.css
   高原竞技编辑部：沙岩米纸面 + 高原青主轴 + 哨响橙信号
   ============================================================ */

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

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

body { margin: 0; }

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

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

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

img { display: block; height: auto; }

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

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

a { color: inherit; }

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

/* ---------- 2. Design tokens ---------- */
:root {
  --yk-teal: #0F6B6B;
  --yk-deep: #0A4B4B;
  --yk-orange: #FF6A2B;
  --yk-mint: #D8E8E4;
  --yk-sand: #F2E8D5;
  --yk-paper: #FBF7EF;
  --yk-ink: #132A3A;
  --yk-gray: #5E6B6E;
  --yk-line: #B9C2BE;
  --yk-green: #2F8F6B;

  --yk-max: 1240px;
  --yk-gutter: clamp(16px, 4vw, 48px);

  --yk-font-head: "Oswald", "Barlow Condensed", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --yk-font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --yk-font-mono: "JetBrains Mono", "IBM Plex Mono", SFMono-Regular, Menlo, Consolas, "Courier New", monospace;

  --yk-shadow: 7px 7px 0 var(--yk-ink);
  --yk-shadow-teal: 7px 7px 0 var(--yk-teal);
  --yk-ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. 中文排版基座 ---------- */
body {
  background: var(--yk-sand);
  color: var(--yk-ink);
  font-family: var(--yk-font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

p { max-width: 40em; }

strong, b { font-weight: 700; color: var(--yk-deep); }

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

/* ---------- 4. 焦点与跳转 ---------- */
:where(a, button, [tabindex], input, select, textarea):focus-visible {
  outline: 2px solid var(--yk-orange);
  outline-offset: 2px;
}

.yk-main { display: block; }
.yk-main:focus { outline: none; }

.yk-skip {
  position: absolute;
  left: 12px;
  top: -120px;
  z-index: 200;
  padding: 10px 16px;
  background: var(--yk-orange);
  color: var(--yk-ink);
  border: 2px solid var(--yk-ink);
  box-shadow: 4px 4px 0 var(--yk-ink);
  font-family: var(--yk-font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  text-decoration: none;
  transition: top .14s var(--yk-ease);
}

.yk-skip:focus,
.yk-skip:focus-visible { top: 12px; }

/* ---------- 5. 页头 ---------- */
.yk-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: var(--yk-paper);
  border-bottom: 3px solid var(--yk-deep);
  box-shadow: 0 3px 0 rgba(19, 42, 58, .10);
  transition: box-shadow .16s var(--yk-ease);
}

.yk-header[data-scrolled] { box-shadow: 0 6px 0 rgba(19, 42, 58, .16); }

.yk-header__inner {
  max-width: var(--yk-max);
  margin: 0 auto;
  padding: 14px var(--yk-gutter) 11px;
  display: grid;
  grid-template-columns: auto minmax(40px, 1fr) auto;
  align-items: center;
  gap: clamp(14px, 2.4vw, 36px);
}

.yk-header__left {
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 0;
}

.yk-brand {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
  color: var(--yk-ink);
  transition: transform .14s var(--yk-ease);
}

.yk-brand:hover { transform: translate(-2px, 0); }

.yk-brand__cn {
  font-family: var(--yk-font-head);
  font-weight: 900;
  font-size: 27px;
  line-height: 1;
  letter-spacing: -.03em;
  padding-bottom: 3px;
  border-bottom: 4px solid var(--yk-orange);
}

.yk-brand__en {
  font-family: var(--yk-font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--yk-teal);
  white-space: nowrap;
}

.yk-context {
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: none;
  font-family: var(--yk-font-mono);
  font-size: 11.5px;
  line-height: 1.5;
  letter-spacing: .03em;
  color: var(--yk-gray);
}

.yk-context__dot {
  flex: none;
  width: 7px;
  height: 7px;
  background: var(--yk-green);
  box-shadow: 0 0 0 3px rgba(47, 143, 107, .18);
}

.yk-context__text { min-width: 0; }

.yk-ruler {
  position: relative;
  align-self: end;
  height: 18px;
  min-width: 0;
  background-image: repeating-linear-gradient(90deg, var(--yk-line) 0 1px, transparent 1px 14px);
  background-repeat: repeat-x;
  background-position: left bottom;
  background-size: auto 10px;
  border-bottom: 1px solid var(--yk-line);
}

.yk-ruler::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: -3px;
  width: 6px;
  height: 6px;
  background: var(--yk-orange);
}

.yk-header__right {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.8vw, 24px);
  min-width: 0;
}

.yk-nav__list {
  display: flex;
  align-items: center;
  gap: 1px;
}

.yk-nav__item { display: block; }

.yk-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 9px;
  font-size: 14px;
  font-weight: 500;
  line-height: 1.2;
  color: var(--yk-ink);
  text-decoration: none;
  white-space: nowrap;
  transition: color .14s var(--yk-ease);
}

.yk-nav__link::after {
  content: "";
  position: absolute;
  left: 9px;
  right: 9px;
  bottom: 1px;
  height: 2px;
  background: var(--yk-orange);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .16s var(--yk-ease);
}

.yk-nav__link:hover { color: var(--yk-deep); }
.yk-nav__link:hover::after,
.yk-nav__link:focus-visible::after { transform: scaleX(1); }

.yk-nav__link[aria-current="page"] {
  color: var(--yk-deep);
  font-weight: 700;
}

.yk-nav__link[aria-current="page"]::after {
  height: 3px;
  background: var(--yk-teal);
  transform: scaleX(1);
}

.yk-nav__link[aria-current="page"] .yk-nav__idx { color: var(--yk-orange); }

.yk-nav__idx {
  font-family: var(--yk-font-mono);
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: .06em;
  color: var(--yk-teal);
}

.yk-nav__text { display: inline-block; }

.yk-header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.yk-navtoggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  border: 2px solid var(--yk-deep);
  background: var(--yk-mint);
  color: var(--yk-deep);
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  line-height: 1.2;
  transition: background-color .14s var(--yk-ease), color .14s var(--yk-ease), border-color .14s var(--yk-ease);
}

.yk-navtoggle:hover { background: var(--yk-orange); color: var(--yk-ink); }

.yk-navtoggle[aria-expanded="true"] {
  background: var(--yk-orange);
  border-color: var(--yk-ink);
  color: var(--yk-ink);
}

.yk-navtoggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
}

.yk-navtoggle__bars span {
  display: block;
  height: 2px;
  background: currentColor;
}

.yk-navtoggle__label { display: inline-block; }

.yk-header__progress {
  height: 3px;
  background: var(--yk-mint);
  overflow: hidden;
}

.yk-header__progress-bar {
  display: block;
  width: 0;
  height: 100%;
  background: var(--yk-orange);
  transition: width .1s linear;
}

/* ---------- 6. 按钮与链接 ---------- */
.yk-btn {
  --yk-btn-bg: var(--yk-paper);
  --yk-btn-fg: var(--yk-ink);
  --yk-btn-bd: var(--yk-ink);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border: 2px solid var(--yk-btn-bd);
  background: var(--yk-btn-bg);
  color: var(--yk-btn-fg);
  font-family: var(--yk-font-body);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: .02em;
  text-decoration: none;
  box-shadow: 4px 4px 0 var(--yk-btn-bd);
  transition: transform .14s var(--yk-ease), box-shadow .14s var(--yk-ease),
              background-color .14s var(--yk-ease), color .14s var(--yk-ease),
              border-color .14s var(--yk-ease);
}

.yk-btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--yk-btn-bd);
}

.yk-btn:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--yk-btn-bd);
}

.yk-btn--solid {
  --yk-btn-bg: var(--yk-orange);
  --yk-btn-fg: var(--yk-ink);
  --yk-btn-bd: var(--yk-ink);
}

.yk-btn--ghost {
  --yk-btn-bg: transparent;
  --yk-btn-fg: var(--yk-deep);
  --yk-btn-bd: var(--yk-teal);
}

.yk-btn--sm {
  padding: 8px 12px;
  font-size: 12.5px;
  box-shadow: 3px 3px 0 var(--yk-btn-bd);
}

.yk-btn--sm:hover { box-shadow: 5px 5px 0 var(--yk-btn-bd); }

.yk-btn-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.yk-link {
  color: var(--yk-teal);
  text-decoration: none;
  border-bottom: 2px solid var(--yk-line);
  transition: color .14s var(--yk-ease), border-color .14s var(--yk-ease);
}

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

/* ---------- 7. 坐标钉 / 标签 / 状态 / 元信息 ---------- */
.yk-pin {
  --yk-pin-size: 14px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: .07em;
  line-height: 1.4;
  color: var(--yk-deep);
}

.yk-pin::before {
  content: "";
  flex: none;
  width: var(--yk-pin-size);
  height: var(--yk-pin-size);
  border: 2px solid var(--yk-teal);
  border-radius: 50%;
  background: transparent;
  box-shadow: 0 0 0 3px rgba(15, 107, 107, .14);
  transition: background-color .14s var(--yk-ease),
              border-color .14s var(--yk-ease),
              box-shadow .14s var(--yk-ease);
}

.yk-pin:hover::before,
.yk-pin:focus-visible::before {
  background: var(--yk-orange);
  border-color: var(--yk-ink);
  box-shadow: 0 0 0 4px rgba(255, 106, 43, .22);
}

.yk-pin--sm { --yk-pin-size: 10px; font-size: 11px; }

.yk-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border: 1px solid var(--yk-teal);
  background: var(--yk-mint);
  color: var(--yk-deep);
  font-family: var(--yk-font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  text-transform: uppercase;
  line-height: 1.5;
}

.yk-tag--orange {
  background: var(--yk-orange);
  border-color: var(--yk-ink);
  color: var(--yk-ink);
}

.yk-tag--ghost {
  background: transparent;
  border-color: var(--yk-line);
  color: var(--yk-gray);
}

.yk-status {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--yk-green);
}

.yk-status::before {
  content: "";
  width: 8px;
  height: 8px;
  background: currentColor;
}

.yk-status--pending { color: var(--yk-orange); }

.yk-meta {
  font-family: var(--yk-font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .06em;
  color: var(--yk-gray);
  max-width: none;
}

.yk-note {
  font-family: var(--yk-font-mono);
  font-size: 12px;
  line-height: 1.85;
  letter-spacing: .03em;
  color: var(--yk-gray);
  border-left: 3px solid var(--yk-orange);
  padding-left: 12px;
  max-width: 32em;
}

/* ---------- 8. 布局与文本组件 ---------- */
.yk-container {
  max-width: var(--yk-max);
  margin: 0 auto;
  padding: 0 var(--yk-gutter);
  width: 100%;
}

.yk-narrow { max-width: 760px; }

.yk-section { padding: clamp(40px, 6vw, 80px) 0; }

.yk-section--tight { padding: clamp(22px, 3vw, 40px) 0; }

.yk-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 12px;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--yk-teal);
}

.yk-eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  background: var(--yk-orange);
}

.yk-h2 {
  font-family: var(--yk-font-head);
  font-weight: 900;
  font-size: clamp(32px, 4.4vw, 56px);
  line-height: 1.02;
  letter-spacing: -.03em;
  color: var(--yk-ink);
  margin: 0 0 18px;
}

.yk-h3 {
  font-family: var(--yk-font-head);
  font-weight: 800;
  font-size: clamp(20px, 2vw, 26px);
  line-height: 1.25;
  letter-spacing: -.015em;
  color: var(--yk-ink);
  margin: 0 0 10px;
}

.yk-lede {
  font-size: clamp(17px, 1.35vw, 20px);
  line-height: 1.7;
  color: var(--yk-deep);
  max-width: 42ch;
  margin: 0 0 24px;
}

.yk-text {
  max-width: 40em;
  margin: 0 0 16px;
  color: var(--yk-ink);
}

.yk-rule {
  height: 0;
  border: 0;
  border-top: 2px solid var(--yk-ink);
  margin: clamp(24px, 4vw, 40px) 0;
}

/* ---------- 9. 栅格 ---------- */
.yk-grid {
  display: grid;
  gap: clamp(18px, 2.6vw, 32px);
}

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

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

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

/* ---------- 10. 卡片 / 数据 / 信息带 / 索引 ---------- */
.yk-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: clamp(18px, 2.4vw, 28px);
  background: var(--yk-paper);
  border: 2px solid var(--yk-ink);
  box-shadow: var(--yk-shadow);
  transition: transform .16s var(--yk-ease), box-shadow .16s var(--yk-ease),
              border-color .16s var(--yk-ease);
}

.yk-card:hover {
  transform: translate(-2px, -2px);
  border-color: var(--yk-teal);
  box-shadow: var(--yk-shadow-teal);
}

.yk-card--mint { background: var(--yk-mint); }

.yk-card--flat { box-shadow: none; }

.yk-card--flat:hover { transform: none; box-shadow: none; }

.yk-card__head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.yk-card__title {
  font-family: var(--yk-font-head);
  font-weight: 800;
  font-size: clamp(20px, 2vw, 26px);
  line-height: 1.15;
  letter-spacing: -.015em;
  margin: 0;
  color: var(--yk-ink);
}

.yk-card__body {
  font-size: 15px;
  line-height: 1.8;
  color: var(--yk-gray);
  max-width: 42em;
}

.yk-card__foot {
  margin-top: auto;
  padding-top: 4px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.yk-data {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.yk-data__value {
  font-family: var(--yk-font-mono);
  font-weight: 700;
  font-size: clamp(26px, 3vw, 36px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--yk-deep);
}

.yk-data__label {
  font-family: var(--yk-font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--yk-gray);
}

.yk-band {
  background: var(--yk-deep);
  color: var(--yk-mint);
  border-top: 2px solid var(--yk-ink);
  border-bottom: 2px solid var(--yk-ink);
  padding: clamp(14px, 2vw, 20px) 0;
}

.yk-band__inner {
  max-width: var(--yk-max);
  margin: 0 auto;
  padding: 0 var(--yk-gutter);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 26px;
  font-family: var(--yk-font-mono);
  font-size: 12.5px;
  letter-spacing: .05em;
}

.yk-band strong { color: var(--yk-orange); }

.yk-index {
  border-top: 2px solid var(--yk-ink);
}

.yk-index__item {
  display: grid;
  grid-template-columns: 66px minmax(0, 1fr);
  gap: clamp(12px, 2vw, 26px);
  padding: 18px 0;
  border-bottom: 1px solid var(--yk-line);
}

.yk-index__num {
  font-family: var(--yk-font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--yk-teal);
  padding-top: 4px;
}

/* ---------- 11. 图像容器 ---------- */
.yk-figure {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0;
}

.yk-figure__img {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--yk-mint);
  border: 2px solid var(--yk-ink);
  box-shadow: 6px 6px 0 var(--yk-teal);
  overflow: hidden;
}

.yk-figure__img > img,
.yk-figure__img > picture,
.yk-figure__img > picture > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.yk-figure--wide .yk-figure__img { aspect-ratio: 21 / 9; }

.yk-figure--tall .yk-figure__img { aspect-ratio: 4 / 5; }

.yk-figure--cut .yk-figure__img {
  border: 0;
  box-shadow: 6px 6px 0 var(--yk-teal);
  clip-path: polygon(0 0, 100% 0, 100% 86%, 0 100%);
}

.yk-figure__cap {
  font-family: var(--yk-font-mono);
  font-size: 11.5px;
  line-height: 1.7;
  letter-spacing: .05em;
  color: var(--yk-gray);
}

/* ---------- 12. 面包屑 ---------- */
.yk-breadcrumb {
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--yk-gray);
}

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

.yk-breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

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

.yk-breadcrumb__link {
  color: var(--yk-teal);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .14s var(--yk-ease), border-color .14s var(--yk-ease);
}

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

/* ---------- 13. 页脚 ---------- */
.yk-footer {
  margin-top: clamp(48px, 8vw, 96px);
  background: var(--yk-sand);
  border-top: 3px solid var(--yk-deep);
  color: var(--yk-ink);
}

.yk-footer__inner {
  max-width: var(--yk-max);
  margin: 0 auto;
  padding: clamp(30px, 5vw, 56px) var(--yk-gutter) clamp(24px, 4vw, 40px);
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr) minmax(0, 1.15fr);
  gap: clamp(24px, 4vw, 56px);
}

.yk-footer__brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  min-width: 0;
}

.yk-footer__logo {
  font-family: var(--yk-font-head);
  font-weight: 900;
  font-size: clamp(24px, 2.6vw, 32px);
  line-height: 1.05;
  letter-spacing: -.03em;
  text-decoration: none;
  color: var(--yk-ink);
  padding-bottom: 4px;
  border-bottom: 4px solid var(--yk-orange);
  transition: transform .14s var(--yk-ease);
}

.yk-footer__logo:hover { transform: translate(-2px, 0); }

.yk-footer__tag {
  font-size: 15px;
  line-height: 1.65;
  color: var(--yk-deep);
  font-weight: 500;
  max-width: 20em;
}

.yk-footer__meta {
  font-family: var(--yk-font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--yk-gray);
  max-width: none;
}

.yk-footer__nav,
.yk-footer__contact { min-width: 0; }

.yk-footer__head {
  margin: 0 0 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--yk-deep);
  font-family: var(--yk-font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--yk-deep);
}

.yk-footer__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px 18px;
}

.yk-footer__link {
  display: inline-block;
  padding: 4px 0;
  font-size: 14.5px;
  line-height: 1.5;
  color: var(--yk-ink);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color .14s var(--yk-ease), border-color .14s var(--yk-ease), transform .14s var(--yk-ease);
}

.yk-footer__link:hover,
.yk-footer__link:focus-visible {
  color: var(--yk-deep);
  border-bottom-color: var(--yk-orange);
  transform: translateX(2px);
}

.yk-footer__contact-list {
  display: grid;
  gap: 10px;
  margin: 0 0 14px;
}

.yk-footer__contact-list li {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
}

.yk-footer__label {
  font-family: var(--yk-font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--yk-gray);
}

.yk-footer__value {
  font-size: 14px;
  line-height: 1.6;
  color: var(--yk-ink);
  word-break: break-word;
}

.yk-footer__note {
  font-family: var(--yk-font-mono);
  font-size: 11.5px;
  line-height: 1.8;
  letter-spacing: .02em;
  color: var(--yk-gray);
  border-left: 3px solid var(--yk-orange);
  padding-left: 10px;
  max-width: 30em;
}

.yk-footer__legal {
  background: var(--yk-deep);
  border-top: 2px solid var(--yk-ink);
  color: var(--yk-mint);
}

.yk-footer__legal-inner {
  max-width: var(--yk-max);
  margin: 0 auto;
  padding: 14px var(--yk-gutter);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
}

.yk-footer__legal-line {
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--yk-mint);
  max-width: none;
}

.yk-footer__legal-line--links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 18px;
}

.yk-footer__legal-link {
  color: var(--yk-mint);
  text-decoration: none;
  border-bottom: 1px solid rgba(216, 232, 228, .45);
  transition: color .14s var(--yk-ease), border-color .14s var(--yk-ease);
}

.yk-footer__legal-link:hover,
.yk-footer__legal-link:focus-visible {
  color: var(--yk-orange);
  border-bottom-color: var(--yk-orange);
}

/* ---------- 14. 响应式 ---------- */
@media (max-width: 1180px) {
  .yk-nav__link { padding: 8px 7px; font-size: 13.5px; }
  .yk-nav__link::after { left: 7px; right: 7px; }
  .yk-ruler { display: none; }
  .yk-header__inner { grid-template-columns: auto minmax(0, 1fr); }
  .yk-header__right { justify-content: flex-end; }
}

@media (max-width: 1000px) {
  .yk-navtoggle { display: inline-flex; }

  .yk-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    padding: 8px var(--yk-gutter) 18px;
    background: var(--yk-paper);
    border-top: 2px solid var(--yk-line);
    border-bottom: 3px solid var(--yk-deep);
    box-shadow: 0 10px 0 rgba(19, 42, 58, .12);
    max-height: calc(100vh - 110px);
    overflow-y: auto;
  }

  .yk-nav[data-open] { display: block; }

  .yk-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .yk-nav__item { width: 100%; }

  .yk-nav__link {
    width: 100%;
    justify-content: space-between;
    padding: 13px 4px;
    font-size: 16px;
    border-bottom: 1px solid var(--yk-line);
  }

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

  .yk-nav__link[aria-current="page"] {
    background: var(--yk-mint);
    box-shadow: inset 4px 0 0 var(--yk-orange);
    padding-left: 12px;
  }

  .yk-nav__idx {
    order: 2;
    font-size: 12px;
    color: var(--yk-teal);
  }

  .yk-header__actions .yk-btn--sm { padding: 8px 11px; }
}

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

  .yk-footer__inner {
    grid-template-columns: minmax(0, 1fr);
    gap: clamp(26px, 5vw, 36px);
  }

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

  .yk-index__item { grid-template-columns: 52px minmax(0, 1fr); }
}

@media (max-width: 640px) {
  body { font-size: 16px; }

  .yk-header__inner { padding: 11px var(--yk-gutter) 9px; gap: 10px; }

  .yk-brand__en { display: none; }

  .yk-brand__cn { font-size: 22px; border-bottom-width: 3px; }

  .yk-context { font-size: 10.5px; letter-spacing: .02em; }

  .yk-header__actions { gap: 8px; }

  .yk-header__actions .yk-btn--sm {
    padding: 8px 10px;
    font-size: 11.5px;
    letter-spacing: 0;
  }

  .yk-navtoggle { padding: 8px 10px; font-size: 11px; }

  .yk-btn { width: auto; }

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

  .yk-footer__legal-inner { padding: 14px var(--yk-gutter); }

  .yk-figure__img { box-shadow: 4px 4px 0 var(--yk-teal); }
}

@media (max-width: 400px) {
  .yk-context__text { font-size: 10px; }
  .yk-brand__cn { font-size: 20px; }
}

/* ---------- 15. 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }

  .yk-card:hover,
  .yk-btn:hover,
  .yk-btn:active,
  .yk-brand:hover,
  .yk-footer__logo:hover,
  .yk-footer__link:hover,
  .yk-footer__link:focus-visible {
    transform: none;
  }

  .yk-nav__link::after { transition: none; }
}