/* =========================================================
   奇异果赛场 · 共享样式 /assets/site.css
   ========================================================= */

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

* { margin: 0; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--bar) + 28px);
}

body {
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
}

button { cursor: pointer; }

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

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

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

/* ---------- 2. Design tokens ---------- */
:root {
  --paper: #F7F2E6;
  --paper-2: #F1EADA;
  --ink: #14110D;
  --night: #0C2340;
  --kiwi: #B6F034;
  --arena: #FFFDF8;
  --seed: #3A2A1B;
  --track: #FF6B2C;
  --moss: #5D6B4A;
  --rust: #B23C0E;

  --line: rgba(20, 17, 13, 0.13);
  --line-strong: rgba(20, 17, 13, 0.30);
  --line-light: rgba(255, 253, 248, 0.16);

  --font-display: "Archivo Narrow", "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", system-ui, sans-serif;
  --font-body: "PingFang SC", "Noto Sans SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --rail: 92px;
  --bar: 66px;
  --maxw: 1440px;
  --gutter: clamp(18px, 3.2vw, 40px);

  --r-sm: 12px;
  --r-md: 20px;
  --r-lg: 28px;
  --r-xl: 36px;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 3. 中文排版基座 ---------- */
body {
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 500;
  line-height: 1.75;
  color: var(--ink);
  background-color: var(--paper);
  padding-left: var(--rail);
  padding-top: var(--bar);
  letter-spacing: 0.005em;
}

h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.012em;
  text-wrap: balance;
}

p { text-wrap: pretty; }

strong, b { font-weight: 700; }

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

:focus-visible {
  outline: 3px solid var(--track);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- 4. 基础版式工具 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: clamp(52px, 6.5vw, 96px);
}

.section__head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: clamp(22px, 3vw, 36px);
}

.section__title {
  font-size: clamp(1.8rem, 3.4vw, 3.2rem);
  line-height: 1.06;
}

.tilt {
  display: inline-block;
  transform: skewX(-4deg);
}

.index-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--moss);
}

.index-label::before {
  content: "";
  width: 18px;
  height: 2px;
  background: var(--track);
  border-radius: 2px;
}

.bento {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(14px, 1.6vw, 24px);
}

.card {
  position: relative;
  background: var(--arena);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: clamp(20px, 2.4vw, 32px);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  background: var(--ink);
  color: var(--arena);
  white-space: nowrap;
}

.tag--kiwi { background: var(--kiwi); color: var(--ink); }
.tag--track { background: var(--track); color: #FFFDF8; }
.tag--ghost {
  background: transparent;
  color: var(--moss);
  border: 1px solid var(--line-strong);
}

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 999px;
  border: 1.5px solid transparent;
  font-family: var(--font-body);
  font-size: 14.5px;
  font-weight: 700;
  line-height: 1.2;
  white-space: nowrap;
  cursor: pointer;
  transition: transform 0.2s var(--ease), background-color 0.2s var(--ease),
              color 0.2s var(--ease), box-shadow 0.2s var(--ease),
              border-color 0.2s var(--ease);
}

.btn--kiwi {
  background: var(--kiwi);
  color: var(--ink);
  box-shadow: 0 2px 0 0 var(--seed);
}
.btn--kiwi:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 0 0 var(--seed);
}
.btn--kiwi:active {
  transform: translateY(1px);
  background: var(--rust);
  color: var(--arena);
  box-shadow: 0 1px 0 0 var(--seed);
}

.btn--dark {
  background: var(--ink);
  color: var(--arena);
}
.btn--dark:hover { transform: translateY(-2px); background: var(--night); }

.btn--ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--ink);
}
.btn--ghost:hover {
  transform: translateY(-2px);
  border-color: var(--ink);
  background: rgba(182, 240, 52, 0.22);
}

/* ---------- 6. Skip link ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: calc(var(--rail) + 14px);
  z-index: 300;
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--arena);
  font-size: 13px;
  font-weight: 700;
  transform: translateY(-180%);
  transition: transform 0.25s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline: 3px solid var(--kiwi);
  outline-offset: 2px;
}

/* ---------- 7. Header ---------- */
.site-header {
  position: relative;
  z-index: 120;
}

.hdr-rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--rail);
  z-index: 122;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 22px 0 18px;
  background-color: var(--night);
  background-image: linear-gradient(180deg, #0C2340 0%, #081a30 100%);
  border-right: 1px solid rgba(255, 253, 248, 0.10);
}

.hdr-rail__word {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.38em;
  color: rgba(255, 253, 248, 0.62);
  text-transform: uppercase;
}

.hdr-rail__cn {
  writing-mode: vertical-rl;
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.32em;
  color: var(--kiwi);
}

.hdr-rail__progress {
  position: relative;
  flex: 1 1 auto;
  width: 4px;
  min-height: 70px;
  border-radius: 99px;
  background: rgba(255, 253, 248, 0.14);
  overflow: hidden;
}

.hdr-rail__fill {
  position: absolute;
  inset: 0;
  display: block;
  background: linear-gradient(180deg, var(--kiwi) 0%, #8FCC1C 100%);
  transform: scaleY(0);
  transform-origin: top center;
  transition: transform 0.12s linear;
}

.hdr-rail__num {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--kiwi);
}

.hdr-bar {
  position: fixed;
  top: 0;
  left: var(--rail);
  right: 0;
  z-index: 121;
  height: var(--bar);
  display: flex;
  align-items: center;
  gap: clamp(12px, 1.8vw, 26px);
  padding: 0 clamp(14px, 2.4vw, 30px);
  background: rgba(247, 242, 230, 0.94);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 0 var(--line-strong), 0 12px 32px -26px rgba(20, 17, 13, 0.6);
}

.hdr-bar::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background-image: repeating-linear-gradient(
    100deg,
    var(--kiwi) 0 12px,
    transparent 12px 27px
  );
  opacity: 0.9;
  pointer-events: none;
}

/* Brand */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  flex: none;
  transition: transform 0.2s var(--ease);
}
.brand:hover { transform: translateY(-1px); }

.brand__mark {
  display: block;
  flex: none;
  width: 38px;
  height: 38px;
  border-radius: 13px;
  background-color: var(--kiwi);
  background-image:
    radial-gradient(circle at 30% 30%, var(--seed) 0 2.2px, transparent 2.4px),
    radial-gradient(circle at 66% 24%, var(--seed) 0 2.2px, transparent 2.4px),
    radial-gradient(circle at 44% 60%, var(--seed) 0 2.2px, transparent 2.4px),
    radial-gradient(circle at 72% 68%, var(--seed) 0 2.2px, transparent 2.4px),
    radial-gradient(circle at 26% 74%, var(--seed) 0 2.2px, transparent 2.4px);
  box-shadow: inset 0 0 0 1.5px rgba(20, 17, 13, 0.85);
}

.brand__text { display: block; }

.brand__name {
  display: block;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.1;
  color: var(--ink);
}

.brand__sub {
  display: block;
  margin-top: 3px;
  font-family: var(--font-mono);
  font-size: 9.5px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--moss);
}

/* Navigation */
.nav {
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.4vw, 22px);
  margin-left: auto;
}

.nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav__link {
  display: block;
  position: relative;
  padding: 9px 12px;
  border-radius: 999px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--ink);
  white-space: nowrap;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease),
              transform 0.2s var(--ease);
}

.nav__link:hover {
  background: rgba(20, 17, 13, 0.06);
  transform: translateY(-2px);
}

.nav__link[aria-current="page"] {
  background: var(--ink);
  color: var(--arena);
  box-shadow: inset 0 0 0 1.5px var(--ink);
}

.nav__util {
  display: flex;
  align-items: center;
  gap: 4px;
  padding-left: 14px;
  border-left: 1px solid var(--line-strong);
}

.nav__util-label {
  font-family: var(--font-mono);
  font-size: 9.5px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--moss);
  margin-right: 2px;
}

.nav__util-link {
  padding: 6px 9px;
  border-radius: 999px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--moss);
  white-space: nowrap;
  transition: color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.nav__util-link:hover {
  color: var(--ink);
  background: rgba(182, 240, 52, 0.42);
}

.hdr-cta { flex: none; }

/* Mobile toggle */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 10px 14px;
  border-radius: 999px;
  border: 1.5px solid var(--ink);
  background: var(--ink);
  color: var(--arena);
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 700;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease);
}

.nav-toggle:hover { background: var(--night); }

.site-header[data-open="true"] .nav-toggle {
  background: var(--kiwi);
  border-color: var(--kiwi);
  color: var(--ink);
}

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 18px;
}

.nav-toggle__bars i {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.25s var(--ease);
}

.site-header[data-open="true"] .nav-toggle__bars i:first-child {
  transform: translateY(3px) rotate(45deg);
}
.site-header[data-open="true"] .nav-toggle__bars i:last-child {
  transform: translateY(-3px) rotate(-45deg);
}

/* ---------- 8. Footer ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-left: calc(-1 * var(--rail));
  padding: clamp(48px, 6vw, 88px) clamp(20px, 4vw, 60px) 0
           calc(var(--rail) + clamp(20px, 4vw, 60px));
  background-color: var(--night);
  background-image: linear-gradient(160deg, #0C2340 0%, #08172b 62%, #0A1E36 100%);
  color: #E9E3D4;
}

.ftr-lanes {
  position: absolute;
  right: -8%;
  bottom: -22%;
  width: min(760px, 82%);
  height: 420px;
  background-image: repeating-linear-gradient(
    102deg,
    rgba(182, 240, 52, 0.16) 0 2px,
    transparent 2px 34px
  );
  transform: skewX(-12deg);
  pointer-events: none;
  opacity: 0.7;
}

.ftr-top {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1.35fr);
  gap: clamp(30px, 4vw, 64px);
  max-width: 1320px;
}

.ftr-brand { min-width: 0; }

.ftr-brand__link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  transition: transform 0.2s var(--ease);
}
.ftr-brand__link:hover { transform: translateY(-2px); }

.ftr-brand__mark {
  display: block;
  flex: none;
  width: 44px;
  height: 44px;
  border-radius: 16px;
  background-color: var(--kiwi);
  background-image:
    radial-gradient(circle at 30% 30%, var(--seed) 0 2.4px, transparent 2.6px),
    radial-gradient(circle at 66% 24%, var(--seed) 0 2.4px, transparent 2.6px),
    radial-gradient(circle at 44% 60%, var(--seed) 0 2.4px, transparent 2.6px),
    radial-gradient(circle at 72% 68%, var(--seed) 0 2.4px, transparent 2.6px);
  box-shadow: inset 0 0 0 2px var(--night);
}

.ftr-brand__name {
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--arena);
}

.ftr-brand__line {
  margin-top: 16px;
  max-width: 34ch;
  font-size: 14.5px;
  line-height: 1.7;
  color: rgba(233, 227, 212, 0.78);
}

.ftr-contact {
  display: flex;
  flex-direction: column;
  gap: 9px;
  margin-top: 22px;
  max-width: 380px;
}

.ftr-contact__text {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: rgba(233, 227, 212, 0.58);
  margin-top: 4px;
}

.copy-chip {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 9px 14px;
  border-radius: 999px;
  border: 1px solid var(--line-light);
  background: rgba(255, 253, 248, 0.06);
  color: #EDE7D8;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 12px;
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease),
              transform 0.2s var(--ease);
}

.copy-chip:hover {
  background: rgba(182, 240, 52, 0.14);
  border-color: rgba(182, 240, 52, 0.55);
  transform: translateY(-1px);
}

.copy-chip:active { transform: translateY(0); }

.copy-chip__label {
  flex: none;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--kiwi);
}

.copy-chip__value {
  flex: 1 1 auto;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  overflow-wrap: anywhere;
  letter-spacing: 0.02em;
}

.copy-chip__hint {
  flex: none;
  padding-left: 9px;
  border-left: 1px solid var(--line-light);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: rgba(255, 253, 248, 0.55);
}

.copy-chip.is-copied {
  background: rgba(182, 240, 52, 0.2);
  border-color: var(--kiwi);
}
.copy-chip.is-copied .copy-chip__hint { color: var(--kiwi); }

.ftr-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 34px);
}

.ftr-col { min-width: 0; }

.ftr-col__title {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding-bottom: 12px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--line-light);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--arena);
}

.ftr-col__num {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--kiwi);
}

.ftr-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.ftr-list a {
  display: inline-block;
  padding: 5px 0;
  font-size: 14px;
  color: rgba(233, 227, 212, 0.76);
  transition: color 0.2s var(--ease), transform 0.2s var(--ease);
}

.ftr-list a:hover {
  color: var(--kiwi);
  transform: translateX(3px);
}

.ftr-bottom {
  position: relative;
  display: flex;
  align-items: center;
  gap: 14px 26px;
  flex-wrap: wrap;
  max-width: 1320px;
  margin-top: clamp(38px, 5vw, 64px);
  padding: 20px 0 26px;
  border-top: 1px solid var(--line-light);
}

.ftr-legal,
.ftr-icp {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: rgba(233, 227, 212, 0.55);
}

.ftr-icp { color: rgba(233, 227, 212, 0.72); }

.to-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  padding: 9px 18px;
  border-radius: 999px;
  border: 1.5px solid rgba(182, 240, 52, 0.55);
  color: var(--kiwi);
  font-family: var(--font-body);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.04em;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease),
              transform 0.2s var(--ease);
}

.to-top::before {
  content: "";
  width: 8px;
  height: 8px;
  border-left: 2px solid currentColor;
  border-top: 2px solid currentColor;
  transform: rotate(45deg) translateY(1px);
}

.to-top:hover {
  background: var(--kiwi);
  color: var(--night);
  transform: translateY(-2px);
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--moss);
}

.breadcrumb li { display: inline-flex; align-items: center; }

.breadcrumb li:not(:last-child)::after {
  content: "/";
  margin-left: 8px;
  color: var(--line-strong);
}

.breadcrumb a {
  color: var(--ink);
  border-bottom: 1px solid var(--line-strong);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.breadcrumb a:hover {
  color: var(--rust);
  border-color: var(--rust);
}

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

/* ---------- 10. 章节索引 ---------- */
.toc {
  position: sticky;
  top: calc(var(--bar) + 28px);
  display: flex;
  flex-direction: column;
  gap: 2px;
  align-self: start;
}

.toc__link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  color: var(--moss);
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease);
}

.toc__link:hover { background: rgba(20, 17, 13, 0.06); color: var(--ink); }

.toc__link.is-current,
.toc__link[aria-current] {
  background: var(--ink);
  color: var(--arena);
}

.toc__num {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  opacity: 0.65;
}

/* ---------- 11. 正文 ---------- */
.prose {
  max-width: 66ch;
  font-size: 17px;
  line-height: 1.78;
  color: var(--ink);
}

.prose > * + * { margin-top: 1.05em; }

.prose h2 {
  font-size: clamp(1.4rem, 2.1vw, 1.95rem);
  line-height: 1.22;
  margin-top: 2em;
}

.prose h3 {
  font-size: 1.14rem;
  font-weight: 700;
  margin-top: 1.7em;
}

.prose ul { list-style: disc; padding-left: 1.25em; }
.prose ol { list-style: decimal; padding-left: 1.35em; }
.prose li + li { margin-top: 0.42em; }

.prose a {
  color: var(--rust);
  border-bottom: 1px solid currentColor;
  transition: color 0.2s var(--ease);
}
.prose a:hover { color: var(--track); }

.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  padding: 2px 6px;
  border-radius: 6px;
  background: rgba(20, 17, 13, 0.07);
}

/* ---------- 12. 图片容器 ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  isolation: isolate;
  border-radius: var(--r-lg);
  background-color: var(--seed);
  background-image: linear-gradient(135deg, #3A2A1B 0%, #14110D 100%);
}

.media-frame > img,
.media-frame > picture > img,
.media-frame > video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }
.media-frame--3x2 { aspect-ratio: 3 / 2; }

.media-frame--slant {
  clip-path: polygon(0 0, 100% 4%, 100% 100%, 0 96%);
  border-radius: 0;
}

.media-frame--round { border-radius: var(--r-xl); }

.media-frame--halftone::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background-image: radial-gradient(circle, rgba(20, 17, 13, 0.55) 1px, transparent 1.2px);
  background-size: 6px 6px;
  opacity: 0.3;
  mix-blend-mode: multiply;
}

.media-frame--grid::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(255, 253, 248, 0.16) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 253, 248, 0.16) 1px, transparent 1px);
  background-size: 56px 56px;
  opacity: 0.5;
}

/* ---------- 13. 显现动效 ---------- */
.has-reveal [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
  will-change: opacity, transform;
}

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

/* ---------- 14. 响应式 ---------- */
@media (max-width: 1240px) {
  .nav__util-label { display: none; }
}

@media (max-width: 1080px) {
  :root {
    --rail: 0px;
    --bar: 64px;
  }

  body { padding-left: 0; }

  .hdr-rail { display: none; }

  .hdr-bar {
    left: 0;
    padding: 0 clamp(12px, 3.2vw, 22px);
    gap: 10px;
  }

  .nav {
    position: fixed;
    top: var(--bar);
    left: 0;
    right: 0;
    z-index: 119;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-left: 0;
    padding: 16px clamp(14px, 4vw, 26px) 24px;
    background-color: var(--night);
    background-image: linear-gradient(180deg, #0C2340 0%, #0A1E36 100%);
    border-bottom: 1px solid rgba(255, 253, 248, 0.14);
    box-shadow: 0 26px 48px -30px rgba(0, 0, 0, 0.85);
    max-height: calc(100dvh - var(--bar));
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-14px);
    transition: opacity 0.28s var(--ease), transform 0.28s var(--ease),
                visibility 0.28s linear;
  }

  .site-header[data-open="true"] .nav {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: none;
  }

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

  .nav__link {
    padding: 15px 14px;
    border-radius: 14px;
    font-size: 16.5px;
    color: #EFE9DA;
  }

  .nav__link:hover {
    background: rgba(255, 253, 248, 0.08);
    transform: none;
  }

  .nav__link[aria-current="page"] {
    background: var(--kiwi);
    color: var(--ink);
    box-shadow: none;
  }

  .nav__util {
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 14px;
    padding: 16px 0 0;
    border-left: 0;
    border-top: 1px solid rgba(255, 253, 248, 0.16);
  }

  .nav__util-link {
    padding: 7px 13px;
    border: 1px solid rgba(255, 253, 248, 0.2);
    border-radius: 999px;
    font-size: 12.5px;
    color: #D9D2C0;
  }

  .nav__util-link:hover {
    background: rgba(182, 240, 52, 0.16);
    color: var(--kiwi);
  }

  .nav-toggle { display: inline-flex; }
  .hdr-cta { margin-left: auto; }

  .ftr-top { grid-template-columns: 1fr; }
  .ftr-lanes { opacity: 0.5; }
  .skip-link { left: 12px; }
}

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

@media (max-width: 720px) {
  body { font-size: 16px; }

  .brand__sub { display: none; }
  .brand__name { font-size: 17px; }
  .brand__mark { width: 34px; height: 34px; border-radius: 11px; }

  .hdr-cta { padding: 10px 15px; font-size: 13px; }

  .ftr-cols { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .ftr-bottom { padding-bottom: 22px; }
  .to-top { margin-left: 0; }

  .toc {
    position: static;
    flex-direction: row;
    overflow-x: auto;
    gap: 6px;
    padding-bottom: 6px;
    -webkit-overflow-scrolling: touch;
  }
  .toc__link { flex: none; border: 1px solid var(--line-strong); }
}

@media (max-width: 520px) {
  .nav-toggle__text { display: none; }
  .nav-toggle { padding: 10px; }

  .hdr-cta { padding: 9px 13px; font-size: 12.5px; }

  .ftr-cols { grid-template-columns: 1fr; }
  .ftr-bottom { gap: 10px; }
  .ftr-legal,
  .ftr-icp { font-size: 11px; }
}

/* ---------- 15. 降低动效 ---------- */
@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;
    scroll-behavior: auto !important;
  }

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

  .hdr-rail__fill { transition: none; }
}