/* ===============================================================
   球友赛场 / QiuYou Stadium — 共享站点样式
   文件：/assets/site.css
   =============================================================== */

/* ---------- 基础 Reset ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-body);
  font-size: var(--size-body);
  line-height: 1.7;
  background: var(--color-bg-light);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

main {
  display: block;
}

ul,
ol {
  list-style: none;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color .2s ease, background-color .2s ease, border-color .2s ease;
}

a:hover {
  color: var(--color-deep);
}

img,
picture,
figure {
  display: block;
  max-width: 100%;
}

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

button:disabled {
  cursor: not-allowed;
  opacity: .6;
}

::selection {
  background: var(--color-primary);
  color: #ffffff;
}

::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-dark);
}

::-webkit-scrollbar-thumb {
  background: var(--color-primary);
  border: 2px solid var(--color-bg-dark);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-neon);
}

[id="main-content"] {
  scroll-margin-top: calc(var(--header-h) + 10px);
}

/* ---------- 设计令牌 ---------- */
:root {
  --color-primary: #FF6B00;
  --color-deep: #0A1F44;
  --color-neon: #C8FF00;
  --color-bg-dark: #0F1423;
  --color-bg-light: #F5F7FA;
  --color-surface-mid: #1E2A3A;
  --color-text: #111827;
  --color-text-inverse: #FFFFFF;
  --color-border: #FF6B00;
  --color-grid: #2A3B4C;

  --font-heading: 'Inter', 'Noto Sans SC', sans-serif;
  --font-body: 'Noto Sans SC', sans-serif;
  --font-mono: 'JetBrains Mono', 'Roboto Mono', monospace;

  --size-h1: 3rem;
  --size-h2: 2rem;
  --size-h3: 1.5rem;
  --size-body: 1rem;
  --size-small: 0.875rem;

  --shadow-hard: 6px 6px 0 #111827;
  --shadow-hard-sm: 3px 3px 0 #111827;
  --radius: 2px;
  --header-h: 72px;
}

/* ---------- 标题与正文 ---------- */
h1,
h2,
h3,
h4 {
  font-family: var(--font-heading);
  font-weight: 900;
  line-height: 1.15;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

h1 {
  font-size: var(--size-h1);
}

h2 {
  font-size: var(--size-h2);
}

h3 {
  font-size: var(--size-h3);
}

p {
  margin-bottom: 1rem;
}

p:last-child {
  margin-bottom: 0;
}

.lead {
  font-size: 1.125rem;
  color: #4B5563;
}

.section--dark .lead,
.section--deep .lead {
  color: rgba(255, 255, 255, .75);
}

.text-mono {
  font-family: var(--font-mono);
  font-size: .875rem;
}

/* ---------- 容器与分区 ---------- */
.container {
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: 24px;
}

.container--narrow {
  max-width: 820px;
}

.section {
  padding-block: 96px;
}

.section--light {
  background: var(--color-bg-light);
  color: var(--color-text);
}

.section--dark {
  background: var(--color-bg-dark);
  color: var(--color-text-inverse);
}

.section--deep {
  background: var(--color-deep);
  color: var(--color-text-inverse);
}

.section--accent {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

.section--dark h1,
.section--dark h2,
.section--dark h3,
.section--deep h1,
.section--deep h2,
.section--deep h3,
.section--accent h1,
.section--accent h2,
.section--accent h3 {
  color: #ffffff;
}

.section--dark .lead,
.section--deep .lead {
  color: rgba(255, 255, 255, .75);
}

.section--accent .lead {
  color: rgba(255, 255, 255, .9);
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-family: var(--font-mono);
  font-size: var(--size-small);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .18em;
  color: var(--color-primary);
}

.section-label::before {
  content: "";
  width: 1.5rem;
  height: 2px;
  background: var(--color-neon);
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-top: .75rem;
}

.section-desc {
  font-size: 1.125rem;
  color: #4B5563;
  max-width: 640px;
  margin-top: .75rem;
}

.section--dark .section-desc,
.section--deep .section-desc {
  color: #9CA3AF;
}

.section--accent .section-desc {
  color: rgba(255, 255, 255, .85);
}

.cyber-grid-bg {
  background-image:
    linear-gradient(rgba(42, 59, 76, .4) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 59, 76, .4) 1px, transparent 1px);
  background-size: 48px 48px;
}

/* ---------- 页头 Hero ---------- */
.page-hero {
  position: relative;
  overflow: hidden;
  background: var(--color-bg-dark);
  padding: calc(var(--header-h) + 56px) 0 56px;
  border-bottom: 3px solid var(--color-primary);
}

.page-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background-image:
    linear-gradient(rgba(42, 59, 76, .3) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 59, 76, .3) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: linear-gradient(115deg, transparent 20%, #000 82%);
  mask-image: linear-gradient(115deg, transparent 20%, #000 82%);
}

.page-hero::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 38%;
  height: 100%;
  background: linear-gradient(105deg, rgba(255, 107, 0, .55) 0%, rgba(255, 107, 0, 0) 100%);
  clip-path: polygon(0 0, 100% 0, 72% 100%, 0 100%);
  pointer-events: none;
}

.page-hero__inner {
  position: relative;
  z-index: 1;
}

.page-hero__title {
  color: #ffffff;
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  text-transform: uppercase;
}

.page-hero__desc {
  color: rgba(255, 255, 255, .75);
  font-size: 1.125rem;
  max-width: 680px;
  margin-top: .875rem;
}

/* ---------- 共享头部 ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 1000;
  height: var(--header-h);
  background: linear-gradient(180deg, rgba(15, 20, 35, .78) 0%, rgba(15, 20, 35, .16) 100%);
  border-bottom: 1px solid transparent;
  transition: background-color .3s ease, border-color .3s ease, box-shadow .3s ease;
}

.site-header.is-solid {
  background: var(--color-deep);
  border-bottom-color: rgba(200, 255, 0, .35);
  box-shadow: 0 10px 30px rgba(2, 6, 23, .35);
}

.site-header.is-solid .nav__link {
  text-shadow: none;
}

.site-header__inner {
  max-width: 1200px;
  margin-inline: auto;
  height: 100%;
  padding-inline: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: .875rem;
}

/* ---------- 品牌 ---------- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: .625rem;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 1.25rem;
  letter-spacing: -.02em;
  color: var(--color-text-inverse);
  text-decoration: none;
}

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

.brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  background: var(--color-primary);
  border: 2px solid var(--color-bg-dark);
  color: #ffffff;
  font-family: var(--font-mono);
  font-size: .75rem;
  font-weight: 800;
  letter-spacing: 0;
  box-shadow: 3px 3px 0 var(--color-bg-dark);
}

.brand__name {
  white-space: nowrap;
}

/* ---------- 导航 ---------- */
.nav {
  display: flex;
  align-items: center;
}

.nav__list {
  display: flex;
  align-items: center;
  gap: .25rem;
}

.nav__item {
  position: relative;
}

.nav__link {
  display: inline-block;
  padding: .5rem .875rem;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: .9375rem;
  color: var(--color-text-inverse);
  text-decoration: none;
  text-shadow: 0 1px 3px rgba(15, 20, 35, .65);
  position: relative;
}

.nav__link::after {
  content: "";
  position: absolute;
  left: .875rem;
  right: .875rem;
  bottom: .25rem;
  height: 2px;
  background: var(--color-neon);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .22s ease;
}

.nav__link:hover {
  color: var(--color-neon);
}

.nav__link:hover::after,
.nav__link[aria-current="page"]::after {
  transform: scaleX(1);
}

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

/* ---------- 汉堡按钮 ---------- */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: 2px solid var(--color-neon);
  background: var(--color-deep);
}

.nav-toggle__line {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-neon);
  margin-inline: auto;
  transition: transform .25s ease, opacity .2s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- 遮罩与进度条 ---------- */
.nav-backdrop {
  position: fixed;
  top: var(--header-h);
  right: 0;
  bottom: 0;
  left: 0;
  background: rgba(15, 20, 35, .72);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: opacity .25s ease, visibility .25s ease;
}

.nav-backdrop[data-open="true"] {
  opacity: 1;
  visibility: visible;
}

.scroll-progress {
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: var(--color-neon);
  z-index: 1001;
  pointer-events: none;
}

body.nav-locked {
  overflow: hidden;
}

/* ---------- Skip Link ---------- */
.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 2000;
  background: var(--color-neon);
  color: var(--color-deep);
  padding: .75rem 1.25rem;
  font-weight: 800;
  border: 2px solid var(--color-bg-dark);
}

.skip-link:focus {
  top: 16px;
}

.skip-link:hover {
  color: var(--color-deep);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1rem;
  line-height: 1;
  padding: .875rem 1.5rem;
  border: 2px solid var(--color-bg-dark);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--color-text);
  background: var(--color-bg-light);
  transition: transform .18s ease, box-shadow .18s ease, background-color .18s ease;
}

.btn:hover {
  transform: translate(-2px, -2px);
}

.btn--primary {
  background: var(--color-primary);
  color: #ffffff;
  box-shadow: var(--shadow-hard-sm);
}

.btn--primary:hover {
  color: #ffffff;
  box-shadow: var(--shadow-hard);
}

.btn--neon {
  background: var(--color-neon);
  color: var(--color-deep);
  box-shadow: var(--shadow-hard-sm);
}

.btn--neon:hover {
  color: var(--color-deep);
  box-shadow: var(--shadow-hard);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-inverse);
  border-color: rgba(255, 255, 255, .7);
}

.btn--ghost:hover {
  background: rgba(255, 255, 255, .12);
  color: #ffffff;
}

.btn--small {
  padding: .625rem 1rem;
  font-size: .875rem;
}

.btn--large {
  padding: 1.125rem 2rem;
  font-size: 1.125rem;
}

/* ---------- 标签与版本徽章 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: .375rem;
  font-family: var(--font-mono);
  font-size: .75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  padding: .3125rem .75rem;
  border: 1px solid var(--color-bg-dark);
  background: transparent;
  color: var(--color-deep);
}

.tag--neon {
  background: var(--color-neon);
  color: var(--color-deep);
}

.tag--orange {
  background: var(--color-primary);
  color: #ffffff;
}

.version-chip {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .375rem .75rem;
  border: 2px solid var(--color-deep);
  background: var(--color-bg-light);
  box-shadow: 2px 2px 0 var(--color-primary);
  font-family: var(--font-mono);
  font-size: .8125rem;
  font-weight: 700;
  color: var(--color-deep);
}

.version-chip::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-neon);
  box-shadow: 0 0 0 2px var(--color-bg-dark);
}

/* ---------- 网格 ---------- */
.grid {
  display: grid;
  gap: 1.5rem;
}

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

.grid--3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid--4 {
  grid-template-columns: repeat(4, 1fr);
}

/* ---------- 卡片 ---------- */
.card {
  background: var(--color-bg-light);
  border: 2px solid var(--color-bg-dark);
  border-radius: var(--radius);
  box-shadow: var(--shadow-hard-sm);
  padding: 1.5rem;
  transition: transform .2s ease, box-shadow .2s ease;
}

.card:hover {
  transform: translate(-3px, -3px);
  box-shadow: var(--shadow-hard);
}

.card--dark {
  background: var(--color-surface-mid);
  border-color: var(--color-grid);
  color: var(--color-text-inverse);
}

.card--orange {
  background: var(--color-primary);
  border-color: var(--color-bg-dark);
  color: #ffffff;
}

.card--dark .card__title,
.card--orange .card__title {
  color: #ffffff;
}

.card__title {
  font-size: 1.25rem;
  line-height: 1.3;
}

.card__meta {
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: .08em;
}

.card__body {
  margin-top: .75rem;
  font-size: .9375rem;
  color: #4B5563;
}

.card--dark .card__body {
  color: rgba(255, 255, 255, .7);
}

.card--orange .card__body {
  color: rgba(255, 255, 255, .85);
}

.card__link {
  display: inline-flex;
  align-items: center;
  gap: .25rem;
  margin-top: 1rem;
  font-weight: 700;
  color: var(--color-primary);
}

.card__link::after {
  content: "→";
  transition: transform .2s ease;
}

.card:hover .card__link::after {
  transform: translateX(4px);
}

.card--dark .card__link {
  color: var(--color-neon);
}

.card--orange .card__link {
  color: #ffffff;
}

/* ---------- 图片占位 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  background:
    repeating-linear-gradient(-45deg, transparent 0 12px, rgba(42, 59, 76, .35) 12px 13px),
    var(--color-surface-mid);
  border: 2px solid var(--color-deep);
}

.media::after {
  content: "IMG";
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .35em;
  text-indent: .35em;
  color: var(--color-neon);
  background: linear-gradient(120deg, rgba(200, 255, 0, .1), transparent 55%);
  pointer-events: none;
}

.media__image {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

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

.media--square {
  aspect-ratio: 1;
}

.media--3x2 {
  aspect-ratio: 3 / 2;
}

/* ---------- 面包屑 ---------- */
.breadcrumb {
  padding: 1.5rem 0 0;
  font-family: var(--font-mono);
  font-size: .8125rem;
  position: relative;
  z-index: 1;
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  align-items: center;
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
}

.breadcrumb__item:not(:last-child)::after {
  content: "/";
  color: rgba(255, 255, 255, .3);
}

.breadcrumb__link {
  color: rgba(255, 255, 255, .6);
  text-decoration: none;
}

.breadcrumb__link:hover {
  color: var(--color-neon);
}

.breadcrumb__current {
  color: var(--color-neon);
  font-weight: 700;
}

/* ---------- 时间轴 ---------- */
.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-grid);
}

.timeline__item {
  position: relative;
  padding-bottom: 2rem;
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__marker {
  position: absolute;
  left: -2rem;
  top: 6px;
  width: 14px;
  height: 14px;
  background: var(--color-primary);
  border: 3px solid var(--color-bg-dark);
  border-radius: 50%;
  box-shadow: 0 0 0 2px var(--color-neon);
}

.timeline__date {
  font-family: var(--font-mono);
  font-size: .8125rem;
  color: var(--color-primary);
}

.timeline__title {
  font-size: 1.25rem;
  margin-top: .25rem;
}

.timeline__desc {
  margin-top: .5rem;
  font-size: .9375rem;
  color: #4B5563;
}

.timeline--dark .timeline__desc {
  color: rgba(255, 255, 255, .7);
}

.timeline--dark .timeline__title {
  color: #ffffff;
}

/* ---------- 折叠面板 ---------- */
.accordion {
  border: 2px solid var(--color-deep);
  background: var(--color-bg-light);
}

.accordion__item {
  border-bottom: 1px solid rgba(17, 24, 39, .12);
}

.accordion__item:last-child {
  border-bottom: none;
}

.accordion__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  padding: 1.25rem 1.5rem;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.125rem;
  text-align: left;
  color: var(--color-deep);
  background: transparent;
}

.accordion__trigger:hover {
  background: rgba(255, 107, 0, .06);
}

.accordion__trigger::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 400;
  color: var(--color-primary);
  transition: transform .2s ease;
  flex-shrink: 0;
}

.accordion__trigger[aria-expanded="true"]::after {
  transform: rotate(45deg);
}

.accordion__panel {
  display: none;
  padding: 0 1.5rem 1.25rem;
  color: #4B5563;
  font-size: .9375rem;
}

.accordion__panel[data-open="true"] {
  display: block;
  animation: accordionIn .25s ease-out;
}

@keyframes accordionIn {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

/* ---------- 说明框 ---------- */
.note {
  border-left: 4px solid var(--color-primary);
  background: rgba(255, 107, 0, .07);
  padding: 1rem 1.25rem;
  font-size: .9375rem;
  color: var(--color-text);
}

.note--neon {
  border-left-color: var(--color-neon);
  background: rgba(200, 255, 0, .07);
}

/* ---------- 滚动显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .5s ease-out, transform .5s ease-out;
}

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

/* ---------- 共享页脚 ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  background: var(--color-deep);
  color: rgba(255, 255, 255, .8);
  border-top: 3px solid var(--color-primary);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 260px;
  height: 260px;
  background:
    repeating-linear-gradient(0deg, transparent 0 23px, rgba(200, 255, 0, .08) 23px 24px),
    repeating-linear-gradient(90deg, transparent 0 23px, rgba(255, 107, 0, .1) 23px 24px);
  pointer-events: none;
}

.site-footer__inner {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin-inline: auto;
  padding: 72px 24px 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 2.5rem;
}

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

.brand--footer {
  color: #ffffff;
}

.brand--footer:hover {
  color: var(--color-neon);
}

.footer-brand__desc {
  margin-top: 1rem;
  font-size: .9375rem;
  color: rgba(255, 255, 255, .72);
  max-width: 360px;
}

.footer-brand__trust {
  margin-top: 1.25rem;
  font-size: .8125rem;
  line-height: 1.75;
  color: rgba(255, 255, 255, .58);
  background: rgba(255, 255, 255, .05);
  border-left: 3px solid var(--color-primary);
  padding: .875rem 1rem;
}

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

.footer-col__title {
  font-size: 1rem;
  color: var(--color-neon);
  text-transform: uppercase;
  letter-spacing: .08em;
  margin-bottom: 1.25rem;
  font-weight: 800;
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: .625rem;
}

.footer-link {
  color: rgba(255, 255, 255, .72);
  font-size: .9375rem;
  transition: color .2s, padding-left .2s;
}

.footer-link:hover {
  color: var(--color-neon);
  padding-left: 4px;
}

.footer-list--contact {
  gap: .875rem;
}

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

.footer-contact__item {
  display: flex;
  flex-direction: column;
  gap: .125rem;
}

.footer-contact__label {
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: .08em;
}

.footer-contact__value {
  color: rgba(255, 255, 255, .85);
  font-size: .9375rem;
  word-break: break-all;
}

.footer-contact__note {
  margin-top: 1rem;
  font-family: var(--font-mono);
  font-size: .8125rem;
  color: var(--color-neon);
}

.footer-bottom {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, .14);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-bottom__copyright {
  font-size: .8125rem;
  color: rgba(255, 255, 255, .55);
}

.footer-bottom__icp {
  font-family: var(--font-mono);
  font-size: .8125rem;
  color: rgba(255, 255, 255, .5);
}

/* ---------- Focus ---------- */
:focus-visible {
  outline: 3px solid var(--color-neon);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .grid--3,
  .grid--4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }
}

@media (max-width: 860px) {
  :root {
    --header-h: 60px;
  }

  .site-header__inner {
    padding-inline: 16px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav {
    position: fixed;
    top: var(--header-h);
    right: 0;
    width: min(340px, 88vw);
    height: calc(100vh - var(--header-h));
    height: calc(100dvh - var(--header-h));
    background: var(--color-bg-dark);
    border-left: 2px solid var(--color-primary);
    padding: 1.5rem;
    transform: translateX(105%);
    visibility: hidden;
    transition: transform .28s ease, visibility .28s ease;
    overflow-y: auto;
    z-index: 1000;
  }

  .nav[data-open="true"] {
    transform: translateX(0);
    visibility: visible;
  }

  .nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: .125rem;
  }

  .nav__link {
    display: block;
    padding: .875rem 1rem;
    font-size: 1.125rem;
    border-left: 3px solid transparent;
    text-shadow: none;
  }

  .nav__link::after {
    display: none;
  }

  .nav__link[aria-current="page"] {
    border-left-color: var(--color-neon);
    background: rgba(200, 255, 0, .06);
  }
}

@media (max-width: 768px) {
  :root {
    --size-h1: 2.25rem;
    --size-h2: 1.625rem;
    --size-h3: 1.25rem;
  }

  .section {
    padding-block: 64px;
  }
}

@media (max-width: 620px) {
  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-bottom {
    flex-direction: column;
  }
}

@media (max-width: 560px) {
  .header-cta {
    display: none;
  }
}

@media (max-width: 480px) {
  .container {
    padding-inline: 16px;
  }

  .page-hero {
    padding: calc(var(--header-h) + 40px) 0 40px;
  }

  .btn--large {
    padding: 1rem 1.5rem;
  }
}

/* ---------- 动效降级 ---------- */
@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;
  }

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

  .nav {
    transition: none;
  }
}