/* ==========================================================================
   8868皇冠赛场 · /assets/site.css
   共享外壳：reset / 变量 / 排版 / 页头 / 页脚 / 通用组件 / 响应式
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-block-start: calc(var(--head-h) + 16px);
}

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

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

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

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

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

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

::selection { background: rgba(201, 162, 39, .28); color: #0F3D2E; }

/* ---------- 2. 变量 ---------- */
:root {
  /* 色板 */
  --ink-green: #0F3D2E;
  --ink-green-deep: #08251C;
  --gold: #C9A227;
  --gold-line: #D9B95C;
  --gold-pale: #F2E4B8;
  --arena-red: #D64545;
  --red-deep: #B83232;
  --paper: #F5F2EA;
  --paper-grey: #E8E2D4;
  --paper-white: #FCFAF5;
  --ink: #1F2A25;
  --muted: #6F7F76;

  /* 字体 */
  --font-display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, "SFMono-Regular", Consolas, "Liberation Mono", monospace;

  /* 字号刻度 12/14/16/20/28/40/56 */
  --fs-12: .75rem;
  --fs-14: .875rem;
  --fs-16: 1rem;
  --fs-20: 1.25rem;
  --fs-28: 1.75rem;
  --fs-40: 2.5rem;
  --fs-56: 3.5rem;

  /* 布局 */
  --wrap: 1240px;
  --gutter: 24px;
  --head-h: 84px;
}

@media (max-width: 1000px) {
  :root { --head-h: 64px; --gutter: 20px; }
}
@media (max-width: 480px) {
  :root { --gutter: 16px; }
}

/* ---------- 3. 基础排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: var(--fs-16);
  line-height: 1.75;
  color: var(--ink);
  background-color: var(--paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

#main-content { padding-block-start: var(--head-h); }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.24;
  color: var(--ink-green);
  letter-spacing: .01em;
}

h1 { font-size: clamp(2rem, 4.4vw, var(--fs-56)); }
h2 { font-size: clamp(1.5rem, 3vw, var(--fs-40)); }
h3 { font-size: clamp(1.15rem, 2vw, var(--fs-28)); }
h4 { font-size: var(--fs-20); }

p { line-height: 1.78; }
p + p { margin-block-start: .9em; }

strong { font-weight: 700; }

:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
  border-radius: 1px;
}
.site-foot :focus-visible { outline-color: var(--gold-pale); }

/* ---------- 4. Skip link ---------- */
.skip-link {
  position: fixed;
  inset-block-start: 8px;
  inset-inline-start: 8px;
  z-index: 300;
  padding: 10px 16px;
  background: var(--ink-green);
  color: var(--paper);
  font-size: var(--fs-14);
  font-weight: 500;
  border: 1px solid var(--gold-line);
  transform: translateY(-160%);
  transition: transform .2s ease;
}
.skip-link:focus-visible {
  transform: translateY(0);
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}

/* ---------- 5. 页头 ---------- */
.site-head {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 120;
  background-color: transparent;
  color: var(--ink-green);
  transition: background-color .28s ease, color .28s ease, box-shadow .28s ease;
}
.site-head::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 1px;
  background-image: linear-gradient(90deg, transparent, var(--gold-line) 10%, var(--gold-line) 90%, transparent);
  opacity: .55;
  pointer-events: none;
}
.site-head[data-scrolled="true"],
.site-head[data-open="true"] {
  background-color: var(--ink-green);
  color: var(--paper);
  box-shadow: 0 1px 0 rgba(217, 185, 92, .42), 0 22px 44px -34px rgba(8, 37, 28, .95);
}

/* 顶部金色刻度尺 */
.head-scale {
  position: absolute;
  inset: 0 0 auto 0;
  height: 5px;
  background-image: repeating-linear-gradient(90deg, var(--gold-line) 0 1px, transparent 1px 14px);
  opacity: .34;
  pointer-events: none;
}

/* 滚动进度条 */
.head-progress {
  position: absolute;
  inset: auto 0 0 0;
  height: 2px;
  width: 100%;
  background-color: var(--gold);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform .12s linear;
  pointer-events: none;
  z-index: 2;
}

.head-inner {
  position: relative;
  z-index: 1;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
  min-height: var(--head-h);
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.4vw, 36px);
}

/* 品牌刊头 */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  min-width: 0;
}
.brand-seal {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .06em;
  line-height: 1;
  padding: 7px 8px;
  color: var(--gold);
  border: 1px solid var(--gold-line);
  background-color: rgba(201, 162, 39, .1);
  transition: background-color .22s ease, color .22s ease;
}
.brand:hover .brand-seal {
  background-color: var(--gold);
  color: var(--ink-green-deep);
}
.brand-type {
  display: flex;
  flex-direction: column;
  min-width: 0;
  line-height: 1.16;
}
.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: .02em;
  white-space: nowrap;
}
.brand-tag {
  margin-block-start: 3px;
  font-size: 11px;
  letter-spacing: .1em;
  color: rgba(15, 61, 46, .68);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: color .28s ease;
}
.site-head[data-scrolled="true"] .brand-tag,
.site-head[data-open="true"] .brand-tag { color: rgba(245, 242, 234, .66); }

/* 移动端菜单按钮 */
.nav-toggle { display: none; }

/* 导航 */
.primary-nav {
  margin-inline-start: auto;
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 26px);
}
.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(4px, 1vw, 18px);
}
.nav-link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 7px;
  padding: 9px 2px;
  font-size: var(--fs-14);
  font-weight: 500;
  letter-spacing: .01em;
  color: inherit;
  transition: color .22s ease;
}
.nav-link::after {
  content: "";
  position: absolute;
  inset-inline-start: 2px;
  inset-block-end: 2px;
  width: 0;
  height: 1px;
  background-color: var(--gold);
  transition: width .26s ease;
}
.nav-link:hover::after,
.nav-link:focus-visible::after,
.nav-link[aria-current="page"]::after { width: calc(100% - 4px); }
.nav-link:hover,
.nav-link[aria-current="page"] { color: var(--gold); }

.nav-index {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--gold);
  opacity: .8;
}
.nav-label { white-space: nowrap; }

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  font-size: var(--fs-12);
  font-weight: 500;
  letter-spacing: .1em;
  white-space: nowrap;
  color: var(--ink-green);
  border: 1px solid var(--gold-line);
  transition: background-color .22s ease, color .22s ease, border-color .22s ease;
}
.nav-cta-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--arena-red);
  box-shadow: 0 0 0 3px rgba(214, 69, 69, .18);
}
.nav-cta:hover,
.nav-cta:focus-visible {
  background-color: var(--ink-green);
  color: var(--paper);
  border-color: var(--ink-green);
}
.site-head[data-scrolled="true"] .nav-cta,
.site-head[data-open="true"] .nav-cta { color: var(--gold); }
.site-head[data-scrolled="true"] .nav-cta:hover,
.site-head[data-scrolled="true"] .nav-cta:focus-visible,
.site-head[data-open="true"] .nav-cta:hover,
.site-head[data-open="true"] .nav-cta:focus-visible {
  background-color: var(--gold);
  color: var(--ink-green-deep);
  border-color: var(--gold);
}

/* ---------- 6. 页脚 ---------- */
.site-foot {
  position: relative;
  background-color: var(--ink-green-deep);
  color: rgba(245, 242, 234, .86);
}
.foot-rule {
  height: 1px;
  background-image: linear-gradient(90deg, transparent, var(--gold) 18%, var(--gold) 82%, transparent);
  opacity: .62;
}
.foot-inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(40px, 5vw, 76px) var(--gutter) clamp(26px, 3vw, 42px);
  display: grid;
  grid-template-columns: 1.5fr .9fr 1.35fr .9fr;
  gap: clamp(26px, 3.4vw, 54px);
}
.foot-brand { min-width: 0; }
.foot-brand-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.foot-seal {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .06em;
  line-height: 1;
  padding: 6px 7px;
  color: var(--gold);
  border: 1px solid var(--gold-line);
  background-color: rgba(201, 162, 39, .1);
}
.foot-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  color: var(--paper);
  letter-spacing: .02em;
}
.foot-summary {
  margin-block-start: 16px;
  max-width: 24ch;
  font-size: var(--fs-14);
  color: rgba(245, 242, 234, .7);
}
.foot-icp {
  margin-block-start: 14px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: .06em;
  color: rgba(217, 185, 92, .8);
}

.foot-col { min-width: 0; }
.foot-title {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--gold);
  margin-block-end: 16px;
  padding-block-end: 10px;
  border-block-end: 1px solid rgba(217, 185, 92, .26);
}
.foot-list {
  display: grid;
  gap: 11px;
  font-size: var(--fs-14);
}
.foot-link {
  position: relative;
  display: inline-block;
  color: rgba(245, 242, 234, .82);
  transition: color .2s ease;
}
.foot-link::after {
  content: "";
  position: absolute;
  inset-inline-start: 0;
  inset-block-end: -2px;
  width: 0;
  height: 1px;
  background-color: var(--gold);
  transition: width .24s ease;
}
.foot-link:hover,
.foot-link:focus-visible { color: var(--gold); }
.foot-link:hover::after,
.foot-link:focus-visible::after { width: 100%; }

.foot-contact-list {
  display: grid;
  gap: 12px;
  font-size: var(--fs-14);
}
.foot-contact-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
}
.foot-contact-key {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--gold);
  padding-block-start: 3px;
}
.foot-contact-val {
  color: rgba(245, 242, 234, .82);
  overflow-wrap: anywhere;
}
.foot-note {
  margin-block-start: 16px;
  font-size: var(--fs-12);
  line-height: 1.7;
  color: rgba(245, 242, 234, .56);
  max-width: 34ch;
}

.foot-base {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 20px var(--gutter) 30px;
  border-block-start: 1px solid rgba(217, 185, 92, .2);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  color: rgba(245, 242, 234, .58);
}
.foot-copy { letter-spacing: .04em; }
.foot-meta { letter-spacing: .06em; color: rgba(245, 242, 234, .44); }

/* ---------- 7. 通用布局组件 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.prose { max-width: 68ch; }
.prose p + p { margin-block-start: 1em; }
.prose > * + * { margin-block-start: 1.1em; }

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--split {
  grid-template-columns: minmax(0, .28fr) minmax(0, .72fr);
  gap: clamp(24px, 4vw, 56px);
  align-items: start;
}

/* 章节色带 */
.section-band {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
  padding-block: 11px;
  border-block: 1px solid rgba(217, 185, 92, .42);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--ink-green);
}

/* 章节标题组 */
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 14px;
  margin-block-end: clamp(18px, 2.6vw, 34px);
}
.section-index {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  font-weight: 600;
  letter-spacing: .16em;
  color: var(--gold);
}
.section-title {
  position: relative;
  padding-block-end: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.45rem, 3vw, var(--fs-40));
  color: var(--ink-green);
}
.section-title::after {
  content: "";
  position: absolute;
  inset-inline-start: 0;
  inset-block-end: 0;
  width: 56px;
  height: 2px;
  background-color: var(--gold);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--ink-green);
}

.rule-gold {
  height: 1px;
  border: 0;
  background-image: linear-gradient(90deg, var(--gold-line), rgba(217, 185, 92, 0));
}

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  font-size: var(--fs-14);
  font-weight: 500;
  letter-spacing: .02em;
  line-height: 1.3;
  border: 1px solid transparent;
  transition: background-color .22s ease, color .22s ease, border-color .22s ease, transform .22s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--gold {
  background-color: var(--gold);
  border-color: var(--gold);
  color: var(--ink-green-deep);
}
.btn--gold:hover,
.btn--gold:focus-visible {
  background-color: var(--ink-green);
  border-color: var(--ink-green);
  color: var(--paper);
}

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

.btn--quiet {
  border-color: var(--gold-line);
  color: var(--ink-green);
  background-color: transparent;
}
.btn--quiet:hover,
.btn--quiet:focus-visible {
  background-color: var(--gold-pale);
  border-color: var(--gold);
  color: var(--ink-green);
}

/* ---------- 9. 卡片 ---------- */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  background-color: var(--paper-white);
  border: 1px solid var(--paper-grey);
  box-shadow: 0 1px 0 rgba(31, 42, 37, .04), 0 18px 34px -32px rgba(15, 61, 46, .55);
  transition: transform .24s ease, border-color .24s ease, box-shadow .24s ease;
}
.card:hover {
  transform: translateY(-2px);
  border-color: var(--gold-line);
  box-shadow: 0 1px 0 rgba(31, 42, 37, .05), 0 26px 42px -32px rgba(15, 61, 46, .6);
}
.card-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-block-end: 12px;
  padding-block-end: 12px;
  border-block-end: 1px solid rgba(217, 185, 92, .34);
}
.card-body { font-size: var(--fs-14); color: var(--ink); }
.card-body > * + * { margin-block-start: .7em; }

/* ---------- 10. 图片容器（页面阶段放占位图） ---------- */
.figure {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--gold-line);
  background-color: var(--ink-green);
  background-image:
    linear-gradient(142deg, rgba(15, 61, 46, .94) 0%, rgba(8, 37, 28, .96) 56%, rgba(201, 162, 39, .34) 100%);
}
.figure-img,
.figure > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.66) contrast(1.06) sepia(.08);
  mix-blend-mode: luminosity;
  opacity: .88;
}
.figure::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(217, 185, 92, .18) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(217, 185, 92, .18) 1px, transparent 1px);
  background-size: 46px 46px;
  opacity: .55;
}
.figure--wide { aspect-ratio: 21 / 9; }
.figure--square { aspect-ratio: 1 / 1; }

/* ---------- 11. 面包屑 ---------- */
.crumb {
  margin-block: clamp(18px, 3vw, 30px) 0;
  font-size: 12.5px;
}
.crumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  color: var(--muted);
}
.crumb-list li + li::before {
  content: "/";
  margin-inline-end: 8px;
  color: var(--gold-line);
}
.crumb-list a {
  color: var(--muted);
  transition: color .2s ease;
}
.crumb-list a:hover,
.crumb-list a:focus-visible {
  color: var(--ink-green);
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-color: var(--gold);
  text-decoration-thickness: 1px;
}
.crumb-current {
  color: var(--ink);
  font-weight: 500;
}

/* ---------- 12. 索引 / 数字 / 角标 ---------- */
.spy-link {
  position: relative;
  display: block;
  padding: 9px 0 9px 16px;
  font-size: var(--fs-14);
  line-height: 1.5;
  color: var(--muted);
  border-inline-start: 1px solid rgba(217, 185, 92, .34);
  transition: color .2s ease, border-color .2s ease;
}
.spy-link::before {
  content: "";
  position: absolute;
  inset-inline-start: -1px;
  inset-block: 0;
  width: 2px;
  background-color: var(--gold);
  transform: scaleY(0);
  transform-origin: 50% 0;
  transition: transform .24s ease;
}
.spy-link:hover { color: var(--ink-green); }
.spy-link[aria-current="true"] {
  color: var(--ink-green);
  font-weight: 500;
  border-inline-start-color: var(--gold-line);
}
.spy-link[aria-current="true"]::before { transform: scaleY(1); }

.num {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: var(--fs-20);
  letter-spacing: -.01em;
  color: var(--ink-green);
  background-color: var(--gold-pale);
  padding: 1px 7px;
  font-variant-numeric: tabular-nums;
}

.badge-red {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 18px;
  height: 18px;
  padding-inline: 5px;
  border-radius: 999px;
  background-color: var(--arena-red);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  line-height: 1;
}

/* ---------- 13. 响应式 ---------- */
@media (max-width: 1000px) {
  /* 移动端菜单按钮 */
  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    margin-inline-start: auto;
    padding: 9px 11px;
    border: 1px solid rgba(217, 185, 92, .6);
    color: var(--ink-green);
    font-size: var(--fs-12);
    letter-spacing: .12em;
    transition: color .24s ease, border-color .24s ease;
  }
  .site-head[data-scrolled="true"] .nav-toggle,
  .site-head[data-open="true"] .nav-toggle {
    color: var(--paper);
    border-color: var(--gold-line);
  }
  .nav-toggle-bars {
    display: grid;
    gap: 3px;
    width: 16px;
  }
  .nav-toggle-bars > span {
    display: block;
    height: 1px;
    width: 100%;
    background-color: currentColor;
    transition: transform .24s ease, opacity .24s ease;
  }
  .site-head[data-open="true"] .nav-toggle-bars > span:nth-child(1) { transform: translateY(4px) rotate(45deg); }
  .site-head[data-open="true"] .nav-toggle-bars > span:nth-child(2) { opacity: 0; }
  .site-head[data-open="true"] .nav-toggle-bars > span:nth-child(3) { transform: translateY(-4px) rotate(-45deg); }
  .nav-toggle-text { white-space: nowrap; }

  /* 导航下拉面板 */
  .primary-nav {
    position: absolute;
    inset: 100% 0 auto 0;
    margin-inline-start: 0;
    display: block;
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    padding-inline: var(--gutter);
    background-color: var(--ink-green-deep);
    border-block-start: 1px solid rgba(217, 185, 92, .3);
    transition: max-height .3s ease, visibility .3s ease, padding .3s ease;
  }
  .site-head[data-open="true"] .primary-nav {
    max-height: calc(100vh - var(--head-h));
    overflow-y: auto;
    visibility: visible;
    padding-block: 6px 24px;
  }
  .nav-list {
    display: block;
    max-width: var(--wrap);
    margin-inline: auto;
  }
  .nav-link {
    align-items: center;
    padding: 15px 2px;
    font-size: var(--fs-16);
    color: rgba(245, 242, 234, .88);
    border-block-end: 1px solid rgba(217, 185, 92, .16);
  }
  .nav-link::after { display: none; }
  .nav-link:hover,
  .nav-link[aria-current="page"] { color: var(--gold); }
  .nav-index { font-size: 11px; }
  .nav-cta {
    display: flex;
    justify-content: center;
    margin-block-start: 18px;
    max-width: var(--wrap);
    margin-inline: auto;
    padding: 13px 16px;
    color: var(--gold);
    font-size: var(--fs-14);
  }
  .nav-cta:hover,
  .nav-cta:focus-visible {
    background-color: var(--gold);
    color: var(--ink-green-deep);
    border-color: var(--gold);
  }

  /* 页脚 */
  .foot-inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .foot-summary,
  .foot-note { max-width: none; }
}

@media (max-width: 860px) {
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }
  .grid--split { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 720px) {
  .brand-tag { display: none; }
  .brand-name { font-size: 17px; }
  .foot-inner { grid-template-columns: minmax(0, 1fr); gap: 30px; }
  .foot-base {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
  .card { padding: 18px; }
}

@media (max-width: 420px) {
  .nav-toggle-text { display: none; }
  .btn { width: 100%; }
}

/* ---------- 14. 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
  .card:hover,
  .btn:hover { transform: none; }
}