/* ============================================================
   雷火电竞内容中心 · 共享样式 /assets/site.css
   1. Reset 与变量 / 2. 排版 / 3. 布局与通用组件
   4. 头部 / 5. 导航 / 6. 页脚 / 7. JS 注入组件
   8. 可访问性与响应式
   ============================================================ */

/* ---------- 1. Reset 与变量 ---------- */
:root {
  --ink: #0A1018;
  --ink-2: #101B28;
  --ink-3: #0B141F;
  --signal: #E8452B;
  --ember: #FF7A3D;
  --gold: #C9A227;
  --arc: #2FD8E6;
  --steel: #4A5C74;
  --mist: #8FA3B8;
  --paper: #F2F5F8;
  --wine: #6B1F2A;
  --teal-deep: #1E3A34;
  --line: rgba(74, 92, 116, 0.45);
  --bw: 2px;
  --shadow-hard: 6px 6px 0 rgba(0, 0, 0, 0.55);
  --shadow-soft: 3px 3px 0 rgba(0, 0, 0, 0.45);
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-display: var(--font-body);
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --wrap: 1240px;
  --gutter: clamp(16px, 4vw, 40px);
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 110px;
}

body {
  margin: 0;
  min-height: 100vh;
  color-scheme: dark;
  background-color: var(--ink);
  background-image:
    radial-gradient(1100px 560px at 85% -8%, rgba(232, 69, 43, 0.14), transparent 68%),
    radial-gradient(820px 460px at 4% 4%, rgba(47, 216, 230, 0.07), transparent 70%),
    repeating-linear-gradient(0deg, rgba(74, 92, 116, 0.1) 0 1px, transparent 1px 56px),
    repeating-linear-gradient(90deg, rgba(74, 92, 116, 0.07) 0 1px, transparent 1px 56px);
  background-repeat: no-repeat, no-repeat, repeat, repeat;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.75;
}

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

button {
  font: inherit;
  color: inherit;
}

a {
  color: var(--arc);
}

#main-content {
  display: block;
  scroll-margin-top: 110px;
}

/* ---------- 2. 排版 ---------- */
h1,
h2,
h3,
h4 {
  margin: 0 0 0.55em;
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: 0.02em;
  color: var(--paper);
}

h1 {
  font-size: clamp(32px, 5.2vw, 68px);
  line-height: 1.05;
}

h2 {
  font-size: clamp(24px, 3.2vw, 36px);
}

h3 {
  font-size: clamp(18px, 2vw, 22px);
  font-weight: 700;
  line-height: 1.35;
}

h4 {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

p {
  margin: 0 0 1em;
  max-width: 38em;
}

.lede {
  max-width: 36em;
  font-size: clamp(16px, 1.55vw, 19px);
  line-height: 1.8;
  color: #cfdae6;
}

.annot {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--arc);
  letter-spacing: 0.02em;
}

.divider-arc {
  height: 2px;
  margin: clamp(24px, 4vw, 48px) 0;
  border: 0;
  background: linear-gradient(90deg, var(--arc), rgba(47, 216, 230, 0.06) 70%, transparent);
}

/* ---------- 3. 布局与通用组件 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: clamp(36px, 6vw, 72px);
  border-top: 1px solid var(--line);
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 16px;
  margin-bottom: clamp(16px, 2.4vw, 28px);
}

.section-num {
  display: inline-block;
  padding: 2px 8px;
  border: 1px solid var(--signal);
  color: var(--signal);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  line-height: 1.6;
}

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}

.grid--7-5 {
  grid-template-columns: 7fr 5fr;
}

.grid--8-4 {
  grid-template-columns: 8fr 4fr;
}

.panel {
  padding: clamp(16px, 2.4vw, 26px);
  background: var(--ink-2);
  border: var(--bw) solid var(--steel);
  box-shadow: var(--shadow-hard);
}

.panel--signal {
  border-color: var(--signal);
  background-image: linear-gradient(140deg, rgba(232, 69, 43, 0.16), rgba(16, 27, 40, 0.2) 55%);
}

.panel--arc {
  border-color: var(--arc);
  background-image: linear-gradient(140deg, rgba(47, 216, 230, 0.12), rgba(16, 27, 40, 0.2) 60%);
}

.panel--gold {
  border-color: var(--gold);
  background-image: linear-gradient(140deg, rgba(201, 162, 39, 0.16), rgba(255, 122, 61, 0.08) 60%);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 20px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
  cursor: pointer;
  border: var(--bw) solid var(--signal);
  background: var(--signal);
  color: #0A1018;
  box-shadow: var(--shadow-hard);
  transition: transform 0.16s var(--ease), box-shadow 0.16s var(--ease), background 0.16s var(--ease), color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.btn:hover {
  transform: translate(2px, 2px);
  box-shadow: var(--shadow-soft);
}

.btn:active {
  transform: translate(4px, 4px);
  box-shadow: 0 0 0 rgba(0, 0, 0, 0);
}

.btn--signal {
  background: var(--signal);
  border-color: var(--signal);
  color: #0A1018;
}

.btn--ghost {
  background: transparent;
  border-color: var(--steel);
  color: var(--paper);
  box-shadow: var(--shadow-hard);
}

.btn--ghost:hover {
  border-color: var(--arc);
  color: var(--arc);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid var(--steel);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  line-height: 1.6;
  white-space: nowrap;
}

.tag--signal {
  border-color: var(--signal);
  color: var(--signal);
}

.tag--arc {
  border-color: var(--arc);
  color: var(--arc);
}

.tag--gold {
  border-color: var(--gold);
  color: var(--gold);
}

.data-table {
  width: 100%;
  border: 1px solid var(--line);
  border-collapse: collapse;
  background: var(--ink-2);
  font-size: 14px;
}

.data-table caption {
  padding: 10px 14px;
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-align: left;
}

.data-table th,
.data-table td {
  padding: 10px 14px;
  border-bottom: 1px solid rgba(74, 92, 116, 0.35);
  text-align: left;
  vertical-align: top;
}

.data-table thead th {
  background: rgba(74, 92, 116, 0.2);
  color: var(--mist);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
}

.data-table .num,
.data-table td.num {
  color: var(--arc);
}

.data-table tbody tr {
  transition: background 0.16s var(--ease);
}

.data-table tbody tr:hover {
  background: rgba(232, 69, 43, 0.1);
}

.media-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  background: var(--ink-2);
  border: var(--bw) solid var(--steel);
  box-shadow: var(--shadow-hard);
}

.media-frame--16x9 {
  aspect-ratio: 16 / 9;
}

.media-frame--4x3 {
  aspect-ratio: 4 / 3;
}

.media-frame--1x1 {
  aspect-ratio: 1 / 1;
}

.media-frame--21x9 {
  aspect-ratio: 21 / 9;
}

.media-frame__img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.92) contrast(1.06) brightness(0.9);
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 45%;
  background: linear-gradient(180deg, rgba(10, 16, 24, 0) 0%, rgba(10, 16, 24, 0.88) 100%);
  pointer-events: none;
}

.media-frame__caption {
  position: relative;
  z-index: 1;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.media-slot {
  display: grid;
  place-items: center;
  width: 100%;
  height: 100%;
  min-height: 160px;
  color: var(--steel);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  background-image: repeating-linear-gradient(135deg, rgba(74, 92, 116, 0.28) 0 2px, transparent 2px 12px);
}

.breadcrumbs {
  padding-block: 16px;
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.breadcrumbs li {
  display: flex;
  align-items: center;
  gap: 10px;
}

.breadcrumbs li + li::before {
  content: "/";
  color: var(--steel);
}

.breadcrumbs a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.breadcrumbs a:hover {
  color: var(--arc);
  border-bottom-color: var(--arc);
}

.toc {
  position: relative;
  padding-left: 2px;
  border-left: 1px solid var(--line);
}

.toc__list {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.toc__link {
  display: block;
  padding: 7px 12px;
  border-left: 3px solid transparent;
  color: var(--mist);
  font-size: 13px;
  line-height: 1.5;
  text-decoration: none;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease), background 0.16s var(--ease);
}

.toc__link:hover {
  color: var(--paper);
  background: rgba(74, 92, 116, 0.18);
}

.toc__link[aria-current="true"] {
  color: var(--paper);
  font-weight: 700;
  border-left-color: var(--signal);
  background: rgba(232, 69, 43, 0.12);
}

/* ---------- 4. 头部 ---------- */
.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 1300;
  padding: 10px 16px;
  border: var(--bw) solid #06121A;
  background: var(--arc);
  color: #06121A;
  font-weight: 700;
  text-decoration: none;
  transform: translateY(-160%);
  transition: transform 0.16s var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 900;
  background: linear-gradient(180deg, rgba(10, 16, 24, 0.99) 0%, rgba(10, 16, 24, 0.94) 100%);
  border-bottom: var(--bw) solid #1c2a3a;
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  transition: border-color 0.16s var(--ease);
}

.site-header::before {
  content: "";
  display: block;
  height: 3px;
  background: linear-gradient(90deg, var(--signal) 0%, var(--ember) 38%, var(--gold) 62%, var(--arc) 100%);
}

.site-header[data-open="true"] {
  border-bottom-color: var(--signal);
}

.header-rail {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(12px, 2vw, 28px);
  min-height: 76px;
  padding-block: 12px;
}

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

.brand__mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border: var(--bw) solid #05090E;
  background: var(--signal);
  color: #0A1018;
  font-size: 20px;
  font-weight: 900;
  line-height: 1;
  transform: rotate(-3deg);
  box-shadow: 4px 4px 0 rgba(47, 216, 230, 0.4);
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  line-height: 1.2;
}

.brand__line {
  font-size: 17px;
  font-weight: 900;
  letter-spacing: 0.03em;
  white-space: nowrap;
}

.brand__meta {
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.brand:hover .brand__line {
  color: var(--ember);
}

.header-side {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 20px);
  min-width: 0;
}

/* ---------- 5. 导航 ---------- */
.site-nav {
  min-width: 0;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(4px, 1.1vw, 16px);
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 10px 2px;
  color: #cfdae6;
  font-size: 13.5px;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.16s var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 4px;
  height: 2px;
  background: var(--arc);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.16s ease-out;
}

.site-nav__link:hover,
.site-nav__link:focus-visible {
  color: var(--paper);
}

.site-nav__link:hover::after,
.site-nav__link:focus-visible::after {
  transform: scaleX(1);
}

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

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

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 14px;
  border: var(--bw) solid var(--signal);
  background: rgba(232, 69, 43, 0.08);
  color: var(--signal);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
  white-space: nowrap;
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.55);
  transition: transform 0.16s var(--ease), box-shadow 0.16s var(--ease), background 0.16s var(--ease), color 0.16s var(--ease);
}

.nav-cta::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--arc);
  box-shadow: 0 0 0 2px rgba(47, 216, 230, 0.25);
}

.nav-cta:hover {
  background: var(--signal);
  color: #0A1018;
  transform: translate(2px, 2px);
  box-shadow: var(--shadow-soft);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 12px;
  border: var(--bw) solid var(--steel);
  background: transparent;
  color: var(--paper);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: border-color 0.16s var(--ease), color 0.16s var(--ease);
}

.nav-toggle:hover {
  border-color: var(--arc);
  color: var(--arc);
}

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

.nav-toggle__bar {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform 0.18s var(--ease), opacity 0.18s var(--ease);
}

.nav-toggle__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
}

.nav-toggle[aria-expanded="true"] {
  border-color: var(--signal);
  color: var(--signal);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 96px);
  background: var(--ink-2);
  border-top: var(--bw) solid var(--steel);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 6px;
  background: linear-gradient(90deg, var(--wine) 0%, var(--signal) 32%, var(--teal-deep) 66%, var(--arc) 100%);
}

.site-footer::after {
  content: "";
  display: block;
  height: 8px;
  opacity: 0.55;
  background: repeating-linear-gradient(90deg, var(--signal) 0 24px, #0A1018 24px 48px, var(--arc) 48px 72px, #0A1018 72px 96px);
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 24px;
  padding-block: clamp(26px, 4vw, 42px) clamp(16px, 2.4vw, 24px);
  border-bottom: 1px solid var(--line);
}

.footer-status {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  max-width: none;
}

.footer-status__dot {
  width: 9px;
  height: 9px;
  background: var(--arc);
  box-shadow: 0 0 10px rgba(47, 216, 230, 0.75);
  animation: status-pulse 2.4s ease-in-out infinite;
}

@keyframes status-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.32; }
}

.footer-lanes {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  max-width: none;
}

.footer-lane {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 14px;
  border: 1px solid var(--steel);
  color: var(--paper);
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
  transition: border-color 0.16s var(--ease), color 0.16s var(--ease), transform 0.16s var(--ease);
}

.footer-lane::before {
  content: "";
  width: 6px;
  height: 14px;
  background: var(--signal);
}

.footer-lane--arc::before {
  background: var(--arc);
}

.footer-lane:hover {
  border-color: var(--signal);
  color: var(--signal);
  transform: translateY(-2px);
}

.footer-lane--arc:hover {
  border-color: var(--arc);
  color: var(--arc);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 36px);
  padding-block: clamp(24px, 4vw, 40px);
}

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

.footer-col__title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 12px;
  color: var(--mist);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  max-width: none;
}

.footer-col__title::before {
  content: "";
  width: 10px;
  height: 10px;
  background: var(--signal);
  box-shadow: 0 0 0 2px rgba(232, 69, 43, 0.2);
}

.footer-col:nth-child(2) .footer-col__title::before {
  background: var(--arc);
  box-shadow: 0 0 0 2px rgba(47, 216, 230, 0.2);
}

.footer-col:nth-child(3) .footer-col__title::before {
  background: var(--gold);
  box-shadow: 0 0 0 2px rgba(201, 162, 39, 0.22);
}

.footer-col:nth-child(4) .footer-col__title::before {
  background: var(--steel);
  box-shadow: 0 0 0 2px rgba(74, 92, 116, 0.28);
}

.footer-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 14px;
  line-height: 1.6;
}

.footer-list--plain {
  gap: 14px;
  font-size: 13px;
}

.footer-list--plain li {
  display: grid;
  gap: 2px;
}

.footer-link {
  color: #c6d3e0;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.footer-link:hover {
  color: var(--arc);
  border-bottom-color: var(--arc);
}

.footer-key {
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
}

.footer-val {
  color: var(--paper);
  font-size: 14px;
  word-break: break-word;
}

.footer-note {
  margin: 14px 0 0;
  max-width: 30em;
  color: var(--mist);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.03em;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-block: 18px;
  border-top: 1px solid var(--line);
}

.footer-legal__list {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  margin: 0;
  max-width: none;
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
}

.footer-meta__brand {
  color: var(--mist);
}

.footer-meta__icp {
  color: var(--gold);
}

/* ---------- 7. JS 注入组件 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1200;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--signal) 0%, var(--ember) 45%, var(--arc) 100%);
  pointer-events: none;
  transition: width 0.1s linear;
}

.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 28px);
  bottom: clamp(14px, 3vw, 28px);
  z-index: 1100;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 14px;
  border: var(--bw) solid var(--steel);
  background: var(--ink-3);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  cursor: pointer;
  box-shadow: var(--shadow-hard);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.2s var(--ease), transform 0.2s var(--ease), visibility 0.2s var(--ease), border-color 0.16s var(--ease), color 0.16s var(--ease);
}

.to-top[data-visible="true"] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.to-top:hover {
  border-color: var(--signal);
  color: var(--signal);
}

/* ---------- 8. 可访问性与响应式 ---------- */
a:focus-visible,
button:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--arc);
  outline-offset: 3px;
}

@media (max-width: 1080px) {
  .brand__line {
    font-size: 15.5px;
  }

  .site-nav__link {
    font-size: 13px;
  }

  .nav-cta {
    padding: 0 12px;
    font-size: 12px;
  }
}

@media (max-width: 920px) {
  html {
    scroll-padding-top: 92px;
  }

  .header-rail {
    min-height: 64px;
    padding-block: 10px;
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    max-height: calc(100dvh - 96px);
    overflow-y: auto;
    padding: 10px var(--gutter) 20px;
    background: var(--ink-3);
    border-top: var(--bw) solid #1c2a3a;
    border-bottom: var(--bw) solid var(--steel);
    box-shadow: 0 14px 24px rgba(0, 0, 0, 0.5);
  }

  .site-nav[data-open="true"] {
    display: block;
  }

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

  .site-nav__list li + li {
    border-top: 1px solid rgba(74, 92, 116, 0.35);
  }

  .site-nav__link {
    display: block;
    padding: 14px 0;
    font-size: 16px;
  }

  .site-nav__link::after {
    left: 0;
    right: auto;
    bottom: 8px;
    width: 34px;
  }

  .site-nav__link[aria-current="page"] {
    padding-left: 12px;
    border-left: 3px solid var(--signal);
  }

  .grid--7-5,
  .grid--8-4 {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 620px) {
  .brand__line {
    font-size: 14px;
  }

  .brand__meta {
    font-size: 10px;
    letter-spacing: 0.05em;
  }

  .brand__mark {
    width: 34px;
    height: 34px;
    font-size: 17px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-legal {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-note {
    max-width: none;
  }
}

@media (max-width: 520px) {
  .nav-cta {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .footer-status__dot {
    animation: none;
    opacity: 1;
  }

  .to-top,
  .scroll-progress {
    transition: none;
  }
}