/* ============================================================
   开云体育在线 · 站点共享样式 /assets/site.css
   夜版体育刊物：夜墨基底 + 纸本奶油反相 + 青蓝秩序 + 竞技橙点缀
   ============================================================ */

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

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

body {
  margin: 0;
  background: var(--ky-night);
  color: var(--ky-white);
  font-family: var(--ky-font-sans);
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img, svg, video { max-width: 100%; display: block; }
button { font: inherit; color: inherit; background: none; border: 0; }
h1, h2, h3, h4 { margin: 0; line-height: 1.15; font-weight: 700; letter-spacing: -0.01em; }
p { margin: 0 0 1em; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: var(--ky-cyan); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--ky-white); }
hr { border: 0; border-top: 1px solid var(--ky-line); margin: 32px 0; }

::selection { background: var(--ky-orange); color: #1A1004; }

/* ---------- 2. 变量 ---------- */
:root {
  --ky-night: #0B1220;
  --ky-night-2: #141E32;
  --ky-line: #26324A;
  --ky-paper: #F3EADA;
  --ky-paper-2: #E1D2B8;
  --ky-ink: #241C16;
  --ky-cyan: #2FB6C9;
  --ky-cyan-deep: #14707F;
  --ky-orange: #FF6A2B;
  --ky-red: #E23A2E;
  --ky-star: #8C99AB;
  --ky-white: #FDFDFB;

  --ky-font-display: "Arial Narrow", "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --ky-font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", sans-serif;
  --ky-font-mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", "IBM Plex Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --ky-shell-w: 1280px;
  --ky-gutter: clamp(20px, 5vw, 64px);
  --ky-header-h: 76px;
  --ky-bleed: clamp(16px, 4vw, 48px);

  --ky-radius-lg: clamp(20px, 3vw, 36px);
  --ky-radius-soft: 20px 20px 20px 6px;
}

/* ---------- 3. 工具层 ---------- */
.ky-shell {
  width: 100%;
  max-width: var(--ky-shell-w);
  margin-inline: auto;
  padding-inline: var(--ky-gutter);
}

.ky-offset-top { padding-top: var(--ky-header-h); }

[id] { scroll-margin-top: calc(var(--ky-header-h) + 24px); }
#main-content { scroll-margin-top: calc(var(--ky-header-h) + 8px); }

.ky-skip {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  display: inline-block;
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--ky-paper);
  color: var(--ky-ink);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform 0.18s ease;
}
.ky-skip:focus,
.ky-skip:focus-visible { transform: translateY(0); color: var(--ky-ink); }

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

/* ---------- 4. 页头 ---------- */
.ky-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 60;
  background: transparent;
  border-bottom: 1px solid transparent;
  color: var(--ky-white);
  transition: background-color 0.24s ease, border-color 0.24s ease;
}

.ky-header[data-scrolled="true"],
.ky-header[data-nav-open="true"] {
  background: rgba(11, 18, 32, 0.95);
  border-bottom-color: var(--ky-line);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.ky-header__inner {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.4vw, 36px);
  min-height: var(--ky-header-h);
}

.ky-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--ky-white);
  flex: 0 0 auto;
}
.ky-brand:hover { color: var(--ky-white); }

.ky-brand__mark {
  position: relative;
  font-family: var(--ky-font-display);
  font-weight: 800;
  font-stretch: condensed;
  text-transform: uppercase;
  font-size: 21px;
  letter-spacing: 0.09em;
  color: var(--ky-white);
  padding-right: 13px;
  border-right: 1px solid var(--ky-line);
}
.ky-brand__mark::after {
  content: "";
  position: absolute;
  right: -3px;
  top: 50%;
  width: 5px;
  height: 5px;
  margin-top: -2.5px;
  border-radius: 50%;
  background: var(--ky-orange);
}

.ky-brand__text { display: flex; flex-direction: column; gap: 1px; }
.ky-brand__name { font-size: 15px; font-weight: 700; letter-spacing: 0.02em; line-height: 1.2; }
.ky-brand__tagline {
  font-family: var(--ky-font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ky-star);
  line-height: 1.3;
}

.ky-nav { margin-left: auto; min-width: 0; }

.ky-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
  overflow-x: auto;
  scrollbar-width: none;
}
.ky-nav__list::-webkit-scrollbar { display: none; }

.ky-nav__item { flex: 0 0 auto; }

.ky-nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  font-size: 15px;
  color: rgba(253, 253, 251, 0.78);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s ease;
}
.ky-nav__link::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 6px;
  height: 2px;
  border-radius: 2px;
  background: var(--ky-orange);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.22s ease;
}
.ky-nav__link:hover { color: var(--ky-white); }
.ky-nav__link:hover::after { transform: scaleX(1); }
.ky-nav__link[aria-current="page"] { color: var(--ky-white); font-weight: 600; }
.ky-nav__link[aria-current="page"]::after { transform: scaleX(1); }

.ky-header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}

.ky-header__cta { padding-inline: 20px; }
.ky-header__cta-short { display: none; }

.ky-navtoggle {
  display: none;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 16px 0 14px;
  border: 1px solid var(--ky-line);
  border-radius: 999px;
  background: rgba(20, 30, 50, 0.6);
  color: var(--ky-white);
  font-size: 14px;
  cursor: pointer;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}
.ky-navtoggle:hover { border-color: var(--ky-cyan-deep); }
.ky-navtoggle__text { font-size: 14px; }

.ky-navtoggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: background-color 0.2s ease;
}
.ky-navtoggle__bars::before,
.ky-navtoggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.22s ease;
}
.ky-navtoggle__bars::before { top: -6px; }
.ky-navtoggle__bars::after { top: 6px; }
.ky-navtoggle[aria-expanded="true"] .ky-navtoggle__bars { background: transparent; }
.ky-navtoggle[aria-expanded="true"] .ky-navtoggle__bars::before { transform: translateY(6px) rotate(45deg); }
.ky-navtoggle[aria-expanded="true"] .ky-navtoggle__bars::after { transform: translateY(-6px) rotate(-45deg); }

.ky-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--ky-cyan), var(--ky-orange));
  transform: scaleX(0);
  transform-origin: 0 50%;
  opacity: 0;
  transition: opacity 0.24s ease;
}
.ky-header[data-scrolled="true"] .ky-progress { opacity: 0.9; }

/* ---------- 5. 页脚（纸面反转区） ---------- */
.ky-footer {
  position: relative;
  margin-top: clamp(56px, 9vw, 120px);
  padding: clamp(40px, 6vw, 76px) 0 clamp(24px, 3vw, 36px);
  background: var(--ky-paper);
  color: var(--ky-ink);
  border-radius: var(--ky-radius-lg) var(--ky-radius-lg) 0 0;
}
.ky-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: var(--ky-gutter);
  right: var(--ky-gutter);
  height: 3px;
  border-radius: 0 0 3px 3px;
  background: linear-gradient(
    90deg,
    var(--ky-cyan) 0 34%,
    var(--ky-orange) 34% 54%,
    var(--ky-paper-2) 54% 100%
  );
}

.ky-footer a { color: rgba(36, 28, 22, 0.82); }
.ky-footer a:hover { color: var(--ky-cyan-deep); }

.ky-footer__inner {
  display: grid;
  grid-template-columns: minmax(240px, 4fr) minmax(0, 8fr);
  gap: clamp(28px, 4vw, 64px);
}

.ky-footer__kicker {
  margin: 0 0 12px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ky-cyan-deep);
}

.ky-footer__brand {
  margin: 0 0 12px;
  font-size: clamp(24px, 2.4vw, 33px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--ky-ink);
}

.ky-footer__statement {
  margin: 0;
  max-width: 36ch;
  font-size: 15px;
  line-height: 1.7;
  color: rgba(36, 28, 22, 0.72);
}

.ky-footer__nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 40px);
}

.ky-footer__grouptitle {
  margin: 0 0 12px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(36, 28, 22, 0.55);
}

.ky-footer__links { display: grid; gap: 2px; }

.ky-footer__link {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  font-size: 15.5px;
  color: rgba(36, 28, 22, 0.82);
  text-decoration: none;
}
.ky-footer__link:hover { text-decoration: underline; }

.ky-footer__contact {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 32px);
  margin-top: clamp(32px, 4vw, 56px);
  padding-top: clamp(24px, 3vw, 36px);
  border-top: 1px solid rgba(36, 28, 22, 0.16);
}

.ky-contact { display: grid; gap: 6px; }
.ky-contact__label {
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(36, 28, 22, 0.55);
}
.ky-contact__value {
  font-size: 15.5px;
  color: var(--ky-ink);
  word-break: break-word;
}

.ky-footer__note {
  margin: 16px 0 0;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  line-height: 1.7;
  color: rgba(36, 28, 22, 0.6);
}

.ky-footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 24px;
  margin-top: clamp(24px, 3vw, 36px);
  padding-top: 18px;
  border-top: 1px solid rgba(36, 28, 22, 0.16);
  font-family: var(--ky-font-mono);
  font-size: 12px;
  color: rgba(36, 28, 22, 0.62);
}

.ky-footer__legal { display: flex; flex-wrap: wrap; gap: 6px 20px; }

.ky-footer__link--legal {
  min-height: 36px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  color: rgba(36, 28, 22, 0.72);
}

.ky-footer__icp { margin: 0; }
.ky-footer__copy { margin: 0 0 0 auto; }

/* ---------- 6. 通用按钮 ---------- */
.ky-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}
.ky-btn--primary {
  background: var(--ky-orange);
  color: #1A1004;
}
.ky-btn--primary:hover { background: #FF8348; color: #1A1004; }
.ky-btn--ghost {
  background: transparent;
  border-color: var(--ky-line);
  color: var(--ky-white);
}
.ky-btn--ghost:hover { border-color: var(--ky-cyan); color: var(--ky-white); }
.ky-btn--paper {
  background: transparent;
  border-color: rgba(36, 28, 22, 0.28);
  color: var(--ky-ink);
}
.ky-btn--paper:hover { border-color: var(--ky-cyan-deep); color: var(--ky-cyan-deep); }

/* ---------- 7. 面包屑 ---------- */
.ky-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 20px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  color: var(--ky-star);
}
.ky-breadcrumb__item { display: inline-flex; align-items: center; }
.ky-breadcrumb__item:not(:first-child)::before {
  content: "/";
  margin-right: 8px;
  color: var(--ky-line);
}
.ky-breadcrumb__item a { color: inherit; text-decoration: none; }
.ky-breadcrumb__item a:hover { color: var(--ky-cyan); }

/* ---------- 8. 章节与标题层级 ---------- */
.ky-section { padding-block: clamp(48px, 7vw, 96px); }

.ky-section__head {
  display: grid;
  gap: 14px;
  max-width: 780px;
  margin-bottom: clamp(28px, 4vw, 48px);
}

.ky-section__num {
  font-family: var(--ky-font-display);
  font-weight: 800;
  font-stretch: condensed;
  font-size: clamp(40px, 7vw, 76px);
  line-height: 0.9;
  letter-spacing: 0.02em;
  color: rgba(253, 253, 251, 0.14);
}

.ky-section__title {
  font-size: clamp(28px, 4vw, 52px);
  line-height: 1.08;
  letter-spacing: -0.015em;
}

.ky-section__lede {
  max-width: 62ch;
  margin: 0;
  font-size: clamp(17px, 1.4vw, 19px);
  line-height: 1.72;
  color: var(--ky-star);
}

.ky-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ky-cyan);
}
.ky-eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  background: currentColor;
}

.ky-h1 {
  font-size: clamp(41px, 7vw, 76px);
  line-height: 1.02;
  letter-spacing: -0.02em;
}
.ky-h2 { font-size: clamp(28px, 4vw, 52px); line-height: 1.08; letter-spacing: -0.015em; }
.ky-h3 { font-size: clamp(21px, 2vw, 26px); line-height: 1.2; }

.ky-lede {
  max-width: 46ch;
  margin: 0;
  font-size: clamp(19px, 1.8vw, 26px);
  line-height: 1.6;
  color: rgba(253, 253, 251, 0.86);
}

/* ---------- 9. 区块底色 ---------- */
.ky-paper {
  background: var(--ky-paper);
  color: var(--ky-ink);
  border-radius: var(--ky-radius-lg) var(--ky-radius-lg) 8px var(--ky-radius-lg);
  padding: clamp(28px, 4vw, 56px);
}
.ky-paper a { color: var(--ky-cyan-deep); }
.ky-paper a:hover { color: var(--ky-ink); }
.ky-paper .ky-section__lede { color: rgba(36, 28, 22, 0.72); }
.ky-paper .ky-eyebrow { color: var(--ky-cyan-deep); }
.ky-paper .ky-section__num { color: rgba(36, 28, 22, 0.12); }

.ky-night {
  background: var(--ky-night-2);
  border: 1px solid var(--ky-line);
  border-radius: var(--ky-radius-lg) var(--ky-radius-lg) 10px var(--ky-radius-lg);
  padding: clamp(24px, 3.4vw, 48px);
}

/* ---------- 10. 网格 ---------- */
.ky-grid { display: grid; gap: clamp(20px, 2.6vw, 36px); }
.ky-grid--halves { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.ky-grid--thirds { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.ky-grid--editorial { grid-template-columns: minmax(0, 3fr) minmax(0, 9fr); }
.ky-grid--aside { grid-template-columns: minmax(200px, 3fr) minmax(0, 9fr); }

/* ---------- 11. 正文容器 ---------- */
.ky-prose { max-width: 68ch; font-size: 17px; line-height: 1.75; }
.ky-prose > * + * { margin-top: 1em; }
.ky-prose h2 { font-size: clamp(26px, 3vw, 33px); margin-top: 1.8em; }
.ky-prose h3 { font-size: clamp(20px, 2vw, 23px); margin-top: 1.6em; }
.ky-prose ul,
.ky-prose ol { padding-left: 1.4em; list-style: disc; }
.ky-prose ol { list-style: decimal; }
.ky-prose li { margin-bottom: 0.5em; }
.ky-prose code {
  font-family: var(--ky-font-mono);
  font-size: 0.88em;
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(47, 182, 201, 0.12);
}
.ky-paper .ky-prose { font-size: 19px; }

/* ---------- 12. 目录跟随 ---------- */
.ky-toc {
  position: sticky;
  top: calc(var(--ky-header-h) + 20px);
}
.ky-toc__title {
  margin: 0 0 14px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ky-star);
}
.ky-toc__list { display: grid; gap: 2px; }
.ky-toc__link {
  display: block;
  padding: 9px 12px;
  border-left: 2px solid var(--ky-line);
  font-size: 15px;
  line-height: 1.4;
  color: rgba(253, 253, 251, 0.7);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}
.ky-toc__link:hover { color: var(--ky-white); border-left-color: var(--ky-cyan-deep); }
.ky-toc__link[aria-current="true"] {
  color: var(--ky-white);
  border-left-color: var(--ky-orange);
  background: rgba(47, 182, 201, 0.08);
  font-weight: 600;
}

/* ---------- 13. 卡片 ---------- */
.ky-card {
  position: relative;
  padding: clamp(20px, 2.4vw, 28px);
  background: var(--ky-night-2);
  border: 1px solid var(--ky-line);
  border-radius: 18px 18px 18px 6px;
  transition: transform 0.24s ease, border-color 0.24s ease, box-shadow 0.24s ease;
}
.ky-card:hover {
  transform: translateY(-4px);
  border-color: var(--ky-cyan-deep);
  box-shadow: 0 22px 48px rgba(0, 0, 0, 0.42);
}
.ky-card--key { border-color: rgba(255, 106, 43, 0.5); }
.ky-card--key::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 22px;
  bottom: 22px;
  width: 3px;
  border-radius: 2px;
  background: var(--ky-orange);
}
.ky-card--overflow { margin-right: calc(-1 * var(--ky-bleed)); }
.ky-card--overflow:hover { transform: translate(clamp(4px, 1vw, 8px), -4px); }

.ky-card__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ky-star);
}
.ky-card__title { margin: 10px 0 8px; font-size: clamp(19px, 1.6vw, 23px); line-height: 1.25; }
.ky-card__body { margin: 0; font-size: 16px; line-height: 1.7; color: rgba(253, 253, 251, 0.72); }

/* ---------- 14. 标签筛选 ---------- */
.ky-chip {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 0 16px;
  border: 1px solid var(--ky-line);
  border-radius: 999px;
  background: transparent;
  color: rgba(253, 253, 251, 0.78);
  font-size: 14px;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}
.ky-chip:hover { border-color: var(--ky-cyan-deep); color: var(--ky-white); }
.ky-chip[aria-pressed="true"] {
  background: var(--ky-cyan);
  border-color: var(--ky-cyan);
  color: #04141A;
  font-weight: 600;
}

/* ---------- 15. 时间轴 ---------- */
.ky-timeline { position: relative; padding-left: 28px; }
.ky-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: linear-gradient(180deg, var(--ky-cyan), var(--ky-line));
}
.ky-timeline__item {
  position: relative;
  padding-bottom: clamp(24px, 3vw, 36px);
}
.ky-timeline__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 8px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--ky-night);
  border: 2px solid var(--ky-cyan);
}
.ky-timeline__item--key::before {
  border-color: var(--ky-orange);
  box-shadow: 0 0 0 4px rgba(255, 106, 43, 0.16);
}
.ky-timeline__date {
  display: block;
  margin-bottom: 6px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ky-star);
}

/* ---------- 16. 数据点与旁注 ---------- */
.ky-stat { display: grid; gap: 4px; }
.ky-stat__num {
  font-family: var(--ky-font-display);
  font-weight: 800;
  font-stretch: condensed;
  font-size: clamp(33px, 4.4vw, 65px);
  line-height: 0.92;
  letter-spacing: 0.01em;
  color: var(--ky-white);
}
.ky-stat__label {
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ky-star);
}

.ky-note {
  margin: 0;
  padding: 4px 0 4px 16px;
  border-left: 2px solid var(--ky-orange);
  font-family: var(--ky-font-mono);
  font-size: 14px;
  line-height: 1.7;
  color: var(--ky-star);
}
.ky-paper .ky-note { color: rgba(36, 28, 22, 0.68); }

/* ---------- 17. 图片容器基础规则 ---------- */
.ky-media {
  position: relative;
  overflow: hidden;
  margin: 0;
  border: 1px solid var(--ky-line);
  border-radius: var(--ky-radius-soft);
  background: linear-gradient(160deg, var(--ky-night-2), var(--ky-night));
}
.ky-media__img,
.ky-media > img,
.ky-media > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.ky-media--16x9 { aspect-ratio: 16 / 9; }
.ky-media--4x3 { aspect-ratio: 4 / 3; }
.ky-media--1x1 { aspect-ratio: 1 / 1; }
.ky-media--hero { aspect-ratio: 5 / 3; min-height: 220px; }
.ky-media--bleed { margin-right: calc(-1 * var(--ky-bleed)); }

.ky-media__tag {
  position: absolute;
  top: 14px;
  left: 14px;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 0 10px;
  border-radius: 999px;
  background: var(--ky-orange);
  color: #1A1004;
  font-family: var(--ky-font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.ky-media__caption {
  margin-top: 10px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  line-height: 1.7;
  color: var(--ky-star);
}

/* ---------- 18. 返回顶部 ---------- */
.ky-backtop {
  position: fixed;
  right: clamp(16px, 3vw, 32px);
  bottom: clamp(16px, 3vw, 32px);
  z-index: 70;
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  cursor: pointer;
  background: conic-gradient(
    var(--ky-cyan) calc(var(--ky-ring, 0) * 1turn),
    rgba(38, 50, 74, 0.9) 0
  );
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.24s ease, transform 0.24s ease, visibility 0.24s;
}
.ky-backtop[data-visible="true"] {
  opacity: 1;
  visibility: visible;
  transform: none;
}
.ky-backtop::before {
  content: "";
  position: absolute;
  inset: 3px;
  border-radius: 50%;
  background: var(--ky-night-2);
}
.ky-backtop__icon {
  position: relative;
  font-size: 16px;
  line-height: 1;
  color: var(--ky-white);
}

/* ---------- 19. 滚动显现 ---------- */
.ky-js [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.32s ease, transform 0.32s ease;
}
.ky-js [data-reveal].is-in { opacity: 1; transform: none; }

/* ---------- 20. 响应式 ---------- */
@media (max-width: 1180px) {
  .ky-brand__tagline { display: none; }
}

@media (max-width: 980px) {
  :root { --ky-header-h: 64px; }

  .ky-nav {
    position: fixed;
    top: var(--ky-header-h);
    left: 0;
    right: 0;
    margin: 0;
    max-height: calc(100dvh - var(--ky-header-h));
    overflow-y: auto;
    padding: 12px var(--ky-gutter) 32px;
    background: var(--ky-night-2);
    border-top: 1px solid var(--ky-line);
    box-shadow: 0 28px 56px rgba(0, 0, 0, 0.55);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-10px);
    transition: opacity 0.22s ease, transform 0.22s ease, visibility 0.22s;
  }
  .ky-nav[data-open="true"] {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: none;
  }

  .ky-nav__list { flex-direction: column; align-items: stretch; gap: 0; overflow: visible; }
  .ky-nav__item { border-bottom: 1px solid var(--ky-line); }
  .ky-nav__link {
    width: 100%;
    min-height: 56px;
    padding: 0 4px;
    font-size: 19px;
    color: rgba(253, 253, 251, 0.86);
  }
  .ky-nav__link::after { display: none; }
  .ky-nav__link[aria-current="page"] { color: var(--ky-orange); }

  .ky-navtoggle { display: inline-flex; }

  .ky-grid--halves,
  .ky-grid--thirds,
  .ky-grid--editorial,
  .ky-grid--aside { grid-template-columns: minmax(0, 1fr); }

  .ky-toc { position: static; }
  .ky-media--bleed,
  .ky-card--overflow { margin-right: 0; }
}

@media (max-width: 900px) {
  .ky-footer__inner { grid-template-columns: minmax(0, 1fr); }
  .ky-footer__contact { grid-template-columns: minmax(0, 1fr); }
  .ky-footer__copy { margin-left: 0; }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .ky-brand__mark { font-size: 18px; padding-right: 11px; }
  .ky-brand__name { display: none; }
  .ky-header__cta { padding-inline: 16px; font-size: 14px; }
  .ky-header__cta-full { display: none; }
  .ky-header__cta-short { display: inline; }
  .ky-navtoggle { padding: 0 14px; }
  .ky-navtoggle__text { display: none; }
  .ky-prose { font-size: 16px; }
}

@media (max-width: 560px) {
  .ky-footer__nav { grid-template-columns: minmax(0, 1fr); gap: 24px; }
  .ky-footer__base { font-size: 11px; }
}

/* ---------- 21. 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .ky-js [data-reveal] { opacity: 1; transform: none; }
  .ky-card:hover,
  .ky-card--overflow:hover { transform: none; }
}