/* =========================================================
   m6手机指南 · 共享样式 /assets/site.css
   暗色终端 × 帮助手册：深空底 / 实色面板 / 玻璃层 / 青绿交互 / 暖橙时间
   ========================================================= */

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; color-scheme: dark; scroll-behavior: smooth; }
body, h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd { margin: 0; }
ul, ol { list-style: none; padding: 0; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; border-top: 1px solid var(--line); }

/* ---------- 变量 ---------- */
:root {
  --bg: #060A12;
  --panel: #0E1725;
  --glass: rgba(22, 34, 54, .58);
  --line: #1B2A44;
  --line-soft: rgba(27, 42, 68, .62);
  --teal: #2CE8B4;
  --teal-bright: #6BF3CE;
  --teal-dim: #0F7F6A;
  --amber: #FF9F45;
  --amber-bright: #FFBC80;
  --ink: #E8F1FB;
  --ink-soft: #C6D6E8;
  --muted: #93A7C0;
  --faint: #5C7396;
  --danger: #FF5D73;

  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --head: "Source Han Sans CN Compressed", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --wrap: 1240px;
  --rail-w: 264px;
  --r-lg: 16px;
  --r-md: 12px;
  --r-sm: 8px;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --dur: .18s;
}

/* ---------- 基础排版 ---------- */
body {
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4, .h-page, .h-sec, .card__title {
  font-family: var(--head);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -.01em;
}
h1, .h-page { font-size: clamp(28px, 3.4vw, 42px); }
h2, .h-sec { font-size: clamp(20px, 2.2vw, 24px); font-weight: 700; }
h3 { font-size: 18px; }
h4 { font-size: 16px; }
p { font-size: 16px; }
small, .small { font-size: 13px; }
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; letter-spacing: .02em; }
.muted { color: var(--muted); }
.link {
  color: var(--teal);
  text-decoration: underline;
  text-decoration-color: rgba(44, 232, 180, .42);
  text-underline-offset: 3px;
}
.link:hover { text-decoration-color: var(--teal); }
::selection { background: rgba(44, 232, 180, .28); }

:focus-visible {
  outline: 2px solid var(--teal);
  outline-offset: 2px;
  border-radius: 6px;
  box-shadow: 0 0 0 1px rgba(6, 10, 18, .9);
}

/* ---------- 容器与栅格 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: clamp(18px, 3vw, 32px);
}
.section { padding-block: clamp(40px, 6vw, 72px); }
.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px 18px;
  margin-bottom: clamp(18px, 2.4vw, 28px);
}
.kicker {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--teal);
}
.grid { display: grid; gap: 18px; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--rail { grid-template-columns: minmax(0, 240px) minmax(0, 1fr); gap: clamp(20px, 3vw, 40px); }
.split { display: grid; grid-template-columns: minmax(0, 38fr) minmax(0, 62fr); gap: clamp(20px, 3vw, 44px); align-items: start; }
.split__aside { position: relative; min-width: 0; }
.split__main { min-width: 0; }
.stack { display: grid; gap: 14px; }

.prose { max-width: 74ch; color: var(--ink-soft); font-size: 15.5px; }
.prose > * + * { margin-top: 1em; }
.prose h2 { margin-top: 1.9em; color: var(--ink); }
.prose h3 { margin-top: 1.5em; color: var(--ink); }
.prose ul { list-style: disc; padding-left: 1.2em; }
.prose li + li { margin-top: .4em; }
.prose strong { color: var(--ink); }
.prose .mono { color: var(--ink); }

/* ---------- 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--muted);
}
.breadcrumbs__item { display: inline-flex; align-items: center; gap: 6px; }
.breadcrumbs__item a:hover { color: var(--teal); }
.breadcrumbs__sep { color: #3A4E6D; }
.breadcrumbs [aria-current="page"] { color: var(--ink); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: var(--glass);
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .01em;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  cursor: pointer;
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease),
              border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.btn:hover { transform: translateY(-2px); border-color: var(--teal); color: var(--teal); }
.btn--primary { background: var(--teal); border-color: var(--teal); color: #04241C; }
.btn--primary:hover { background: var(--teal-bright); border-color: var(--teal-bright); color: #04241C; }
.btn--ghost { background: transparent; }
.btn--sm { padding: 8px 14px; font-size: 13px; }

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  transform: translateY(-180%);
  padding: 10px 16px;
  border-radius: var(--r-sm);
  background: var(--teal);
  color: #052A21;
  font-weight: 700;
  transition: transform var(--dur) var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 滚动进度 ---------- */
.progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 120;
  background: transparent;
  pointer-events: none;
}
.progress__fill {
  display: block;
  height: 100%;
  width: 0;
  background: var(--teal);
  box-shadow: 0 0 12px rgba(44, 232, 180, .55);
}

/* ---------- 头部 ---------- */
.site-header { position: sticky; top: 0; z-index: 70; }

.header-bar {
  position: relative;
  z-index: 80;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 11px clamp(18px, 3vw, 32px);
  background: rgba(9, 14, 24, .86);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}
.header-bar__actions { display: flex; align-items: center; gap: 10px; flex: 0 0 auto; }

.brand { display: inline-flex; align-items: center; gap: 12px; min-width: 0; }
.brand__mark {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--teal);
  color: #052A21;
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 800;
}
.brand__text { display: flex; flex-direction: column; min-width: 0; line-height: 1.3; }
.brand__name {
  font-family: var(--head);
  font-size: 17px;
  font-weight: 800;
  letter-spacing: .01em;
  white-space: nowrap;
}
.brand__tagline {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 12px;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.nav-toggle:hover { border-color: var(--teal); color: var(--teal); }
.nav-toggle__bars { position: relative; display: block; width: 16px; height: 2px; background: var(--teal); }
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  background: var(--teal);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}
.nav-toggle__bars::before { top: -5px; }
.nav-toggle__bars::after { top: 5px; }
.nav-toggle__text { letter-spacing: .08em; }
.site-header[data-open="true"] .nav-toggle__bars { background: transparent; }
.site-header[data-open="true"] .nav-toggle__bars::before { transform: translateY(5px) rotate(45deg); }
.site-header[data-open="true"] .nav-toggle__bars::after { transform: translateY(-5px) rotate(-45deg); }

.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 60;
  background: rgba(4, 7, 13, .68);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur) var(--ease);
}
.site-header[data-open="true"] .nav-scrim { opacity: 1; pointer-events: auto; }

/* ---------- 侧边轨道 ---------- */
.rail {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  z-index: 75;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px 14px;
  background: var(--panel);
  border-right: 1px solid var(--line);
  transition: width var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.rail__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 0 6px 12px;
  border-bottom: 1px solid var(--line);
}
.rail__caption { font-family: var(--mono); font-size: 11px; letter-spacing: .16em; color: #3E5578; }
.rail-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 9px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .06em;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.rail-toggle:hover { color: var(--teal); border-color: rgba(44, 232, 180, .5); }
.rail-toggle__ico { display: block; transition: transform var(--dur) var(--ease); }
.rail__list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1 1 auto;
  overflow-y: auto;
  padding-top: 4px;
}
.rail__link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 11px 12px;
  border-left: 2px solid transparent;
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  color: var(--muted);
  font-size: 14.5px;
  font-weight: 600;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.rail__link:hover { color: var(--ink); background: rgba(22, 34, 54, .7); }
.rail__link[aria-current="page"] { color: var(--ink); background: rgba(44, 232, 180, .08); border-left-color: var(--teal); }
.rail__link[aria-current="page"] .rail__idx { color: var(--teal); }
.rail__idx { flex: 0 0 auto; font-family: var(--mono); font-size: 11px; letter-spacing: .06em; color: #3E5578; }
.rail__label { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.rail__note {
  margin-top: auto;
  padding: 10px 6px 0;
  border-top: 1px solid var(--line);
  font-size: 11.5px;
  line-height: 1.6;
  color: var(--faint);
}

.rail[data-collapsed="true"] { width: 88px; padding-inline: 10px; }
.rail[data-collapsed="true"] .rail__caption,
.rail[data-collapsed="true"] .rail__label,
.rail[data-collapsed="true"] .rail__note,
.rail[data-collapsed="true"] .rail-toggle__text { display: none; }
.rail[data-collapsed="true"] .rail__head { justify-content: center; }
.rail[data-collapsed="true"] .rail-toggle__ico { transform: rotate(180deg); }
.rail[data-collapsed="true"] .rail__link { justify-content: center; gap: 0; padding: 12px 6px; }

@media (min-width: 1024px) {
  body { padding-left: var(--rail-w); }
}

/* ---------- 卡片 ---------- */
.card {
  position: relative;
  padding: 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.card:hover { transform: translateY(-4px); border-color: var(--teal); }
.card--glass {
  background: var(--glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.card__title { font-size: 18px; line-height: 1.35; }
.card__body { margin-top: 8px; color: var(--ink-soft); font-size: 14.5px; }
.card__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
  margin-top: 14px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--muted);
}

/* ---------- 日期与标签 ---------- */
.date-chip { font-family: var(--mono); font-size: 12.5px; font-weight: 700; letter-spacing: .04em; color: var(--amber); }
.card:hover .date-chip { color: var(--amber-bright); }
.date-anchor {
  display: block;
  margin-left: -.05em;
  font-family: var(--mono);
  font-size: clamp(40px, 6vw, 64px);
  font-weight: 800;
  line-height: .92;
  letter-spacing: -.03em;
  color: var(--amber);
}
.tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(22, 34, 54, .5);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: .04em;
}
.tag--teal { color: var(--teal); border-color: rgba(44, 232, 180, .4); }
.tag--orange { color: var(--amber); border-color: rgba(255, 159, 69, .42); }
.tag--red { color: var(--danger); border-color: rgba(255, 93, 115, .45); }

/* ---------- 时间轴 ---------- */
.timeline { margin: 0; padding: 0 0 0 26px; border-left: 1px solid var(--line); }
.timeline__item { position: relative; padding-bottom: 26px; }
.timeline__item::before {
  content: "";
  position: absolute;
  left: -31px;
  top: 9px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--line);
}
.timeline__item[data-state="new"]::before { background: var(--teal); border-color: var(--teal); box-shadow: 0 0 0 4px rgba(44, 232, 180, .14); }
.timeline__item[data-state="issue"]::before { background: var(--danger); border-color: var(--danger); }
.timeline__item:last-child { padding-bottom: 0; }
.timeline__date {
  display: block;
  margin-bottom: 6px;
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--amber);
}
.timeline__body { color: var(--ink-soft); font-size: 14.5px; }

/* ---------- 对照表 ---------- */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--panel);
}
.ctable { min-width: 560px; font-size: 14px; }
.ctable th {
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  background: rgba(22, 34, 54, .52);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--muted);
  text-align: left;
  white-space: nowrap;
}
.ctable td { padding: 13px 16px; border-bottom: 1px solid var(--line-soft); color: var(--ink-soft); vertical-align: top; }
.ctable tbody tr:last-child td { border-bottom: 0; }
.ctable tbody tr:hover { background: rgba(44, 232, 180, .05); }
.ctable td .mono { color: var(--ink); }

/* ---------- 折叠面板 ---------- */
.accordion {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--panel);
  overflow: hidden;
}
.accordion__item + .accordion__item { border-top: 1px solid var(--line); }
.accordion__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  width: 100%;
  padding: 16px 18px;
  text-align: left;
  color: var(--ink);
  font-family: var(--head);
  font-size: 16px;
  font-weight: 700;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}
.accordion__trigger:hover { background: rgba(22, 34, 54, .6); }
.accordion__trigger::after { content: "+"; flex: 0 0 auto; font-family: var(--mono); font-size: 16px; color: var(--teal); }
.accordion__trigger[aria-expanded="true"] { color: var(--teal); }
.accordion__trigger[aria-expanded="true"]::after { content: "–"; }
.accordion__panel { padding: 0 18px 18px; color: var(--ink-soft); font-size: 14.5px; }
.accordion__panel[hidden] { display: none; }

/* ---------- 图片容器（页面阶段放占位图） ---------- */
.media {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--panel);
}
.media img, .media svg { width: 100%; height: 100%; object-fit: cover; }
.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 4 / 5; }
.media--diag { clip-path: polygon(0 0, 100% 0, 100% 88%, 0 100%); }
.media__cap {
  position: absolute;
  left: 12px;
  bottom: 12px;
  padding: 4px 9px;
  border-radius: 6px;
  background: rgba(6, 10, 12, .72);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .04em;
}
.media-grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

/* ---------- 装饰：等宽数字群集 ---------- */
.numfield {
  position: absolute;
  inset: auto 0 0 0;
  pointer-events: none;
  user-select: none;
  overflow: hidden;
  white-space: nowrap;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .34em;
  color: rgba(147, 167, 192, .14);
}

/* ---------- 复制按钮 ---------- */
.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 2px 4px;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--ink);
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.copy-btn:hover { color: var(--teal); background: rgba(44, 232, 180, .08); }
.copy-btn::after { content: "复制"; font-size: 11px; letter-spacing: .06em; color: var(--faint); }
.copy-btn[data-copied="true"]::after { content: "已复制"; color: var(--teal); }

/* ---------- 显现 ---------- */
.js [data-reveal] { opacity: 0; transform: translateY(10px); }
.js [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
  transition: opacity .4s var(--ease), transform .4s var(--ease);
}

/* ---------- 页脚 ---------- */
.site-footer {
  margin-top: clamp(48px, 8vw, 96px);
  border-top: 1px solid var(--line);
  background: #080D18;
  color: var(--ink);
}
.footer__grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: clamp(24px, 3vw, 40px);
  padding-block: clamp(36px, 5vw, 56px) 8px;
}
.footer__brand { display: flex; flex-direction: column; gap: 14px; min-width: 0; }
.footer__note { max-width: 34ch; color: var(--muted); font-size: 13.5px; line-height: 1.7; }
.footer__col { min-width: 0; }
.footer__title {
  margin-bottom: 14px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .14em;
  color: var(--teal);
}
.footer__list { display: grid; gap: 10px; }
.footer__link { display: inline-block; color: var(--muted); font-size: 14px; transition: color var(--dur) var(--ease); }
.footer__link::before { content: "›"; margin-right: 8px; color: #3E5578; transition: color var(--dur) var(--ease); }
.footer__link:hover { color: var(--ink); }
.footer__link:hover::before { color: var(--teal); }

.footer__contact {
  display: grid;
  gap: 18px;
  padding-block: 24px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.contact-list { display: grid; gap: 10px; }
.contact-list__item { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 14px; font-size: 14px; }
.contact-list__key { min-width: 72px; font-family: var(--mono); font-size: 12px; letter-spacing: .08em; color: #3E5578; }
.contact-list__val { font-family: var(--mono); font-size: 13px; color: var(--ink); }
.footer__notice { max-width: 72ch; color: var(--muted); font-size: 13.5px; line-height: 1.7; }

.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-block: 20px 40px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--faint);
}
.footer__legal { margin: 0; }
.footer__legal-links { display: flex; flex-wrap: wrap; gap: 18px; }
.footer__legal-links .footer__link { font-family: var(--mono); font-size: 12px; }

/* ---------- 响应式 ---------- */
@media (max-width: 1023px) {
  .nav-toggle { display: inline-flex; }
  .rail {
    width: min(86vw, 320px);
    padding: 84px 16px 20px;
    transform: translateX(-102%);
    box-shadow: 8px 0 40px rgba(0, 0, 0, .5);
  }
  .site-header[data-open="true"] .rail { transform: translateX(0); }
  .rail[data-collapsed="true"] { width: min(86vw, 320px); padding-inline: 16px; }
  .rail[data-collapsed="true"] .rail__caption { display: block; }
  .rail[data-collapsed="true"] .rail__label { display: inline; }
  .rail[data-collapsed="true"] .rail__note { display: block; }
  .rail[data-collapsed="true"] .rail-toggle__text { display: inline; }
  .rail[data-collapsed="true"] .rail__head { justify-content: space-between; }
  .rail[data-collapsed="true"] .rail-toggle__ico { transform: none; }
  .rail[data-collapsed="true"] .rail__link { justify-content: flex-start; gap: 12px; padding: 11px 12px; }
}

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

@media (max-width: 640px) {
  .grid--2, .grid--3 { grid-template-columns: minmax(0, 1fr); }
  .brand__tagline { display: none; }
  .header-bar { padding-inline: 16px; }
  .footer__grid { grid-template-columns: minmax(0, 1fr); gap: 26px; }
  .footer__bottom { justify-content: flex-start; }
  .media--diag { clip-path: polygon(0 0, 100% 0, 100% 93%, 0 100%); }
}

/* ---------- 降级动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .card:hover, .btn:hover { transform: none; }
  .js [data-reveal] { opacity: 1; transform: none; }
}