/* ==========================================================================
   新利体育赛事 · 共享样式表 /assets/site.css
   夜间通勤观赛舱：黑蓝基底 / 深蓝切角面板 / 荧光绿数据锚点 / 暖橙重点场次
   ========================================================================== */

/* 1. Reset ---------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, h5, p, figure, blockquote, dl, dd, ul, ol { margin: 0; }
ul, ol { padding: 0; }
ul[class], ol[class] { list-style: none; }
img, svg, video, canvas { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }
main { display: block; }

/* 2. Tokens --------------------------------------------------------------- */
:root {
  --ink-950: #050B16;
  --navy-900: #0A1F44;
  --navy-800: #123A6B;
  --white: #F2F5F9;
  --slate: #8FA3C0;
  --green: #00E676;
  --green-dim: #00A854;
  --orange: #FF6D00;
  --amber: #FFC24A;
  --steel: #2A3F63;

  --rail-w: 88px;
  --shell-max: 1280px;
  --cut: 18px;

  --font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: Inter, "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --ease: cubic-bezier(.2, .7, .3, 1);
}

/* 3. Base ---------------------------------------------------------------- */
body {
  min-height: 100vh;
  overflow-x: hidden;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: .01em;
  color: var(--white);
  background-color: var(--ink-950);
  background-image:
    radial-gradient(1200px 620px at 88% -12%, rgba(18, 58, 107, .58), rgba(5, 11, 22, 0) 70%),
    radial-gradient(760px 520px at -6% 108%, rgba(0, 230, 118, .08), rgba(5, 11, 22, 0) 68%);
  background-attachment: fixed;
}
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -.01em;
  text-wrap: balance;
}
p { text-wrap: pretty; }

:focus-visible { outline: 2px solid var(--green); outline-offset: 2px; }

/* 4. Utilities ----------------------------------------------------------- */
.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .04em;
}
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}
.skip-link {
  position: absolute;
  left: 8px;
  top: -60px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--green);
  color: var(--ink-950);
  font-size: 14px;
  font-weight: 700;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%);
  transition: top .18s var(--ease);
}
.skip-link:focus { top: 8px; }

/* 5. Layout -------------------------------------------------------------- */
.shell {
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding-inline: 20px;
}
.section {
  position: relative;
  padding-block: 72px;
}
.section--tight { padding-block: 48px; }
.section__head {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 36px;
}
.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--green);
}
.eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--green);
}
.section-title {
  font-size: clamp(28px, 5vw, 48px);
  color: var(--white);
}
.lede {
  max-width: 62ch;
  font-size: clamp(15px, 1.7vw, 18px);
  color: var(--slate);
}
.grid {
  display: grid;
  gap: 24px;
  grid-template-columns: 1fr;
}
.stack { display: grid; gap: 16px; }
.divider {
  height: 1px;
  border: 0;
  margin: 0;
  background: linear-gradient(90deg, rgba(42, 63, 99, 0), var(--steel) 18%, var(--steel) 82%, rgba(42, 63, 99, 0));
}

/* 6. Cut panels ---------------------------------------------------------- */
.cut-panel {
  --cut: 18px;
  --panel-edge: var(--steel);
  --panel-fill: linear-gradient(160deg, rgba(18, 58, 107, .58), rgba(10, 31, 68, .92));
  position: relative;
  isolation: isolate;
  padding: 24px;
  transition: transform .22s var(--ease);
}
.cut-panel::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background-color: var(--panel-edge);
  clip-path: polygon(var(--cut) 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%, 0 var(--cut));
  transition: background-color .22s var(--ease);
}
.cut-panel::after {
  content: "";
  position: absolute;
  inset: 1px;
  z-index: 1;
  background: var(--panel-fill);
  clip-path: polygon(calc(var(--cut) - 1px) 0, 100% 0, 100% calc(100% - var(--cut) + 1px), calc(100% - var(--cut) + 1px) 100%, 0 100%, 0 calc(var(--cut) - 1px));
  pointer-events: none;
}
.cut-panel > * { position: relative; z-index: 2; }
.cut-panel:hover { transform: translateY(-2px); }
.cut-panel:hover::before { background-color: var(--green); }
.cut-panel--accent { --panel-edge: var(--green); }
.cut-panel--solid { --panel-fill: linear-gradient(160deg, var(--navy-900), #061229); }

/* 7. Buttons ------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 11px 20px;
  border: 1px solid var(--steel);
  background: rgba(18, 58, 107, .28);
  color: var(--white);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .06em;
  text-align: center;
  clip-path: polygon(10px 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%, 0 10px);
  transition: background-color .18s var(--ease), color .18s var(--ease), border-color .18s var(--ease), transform .18s var(--ease);
}
.btn:hover { transform: translateY(-2px); border-color: var(--green); color: var(--green); }
.btn:focus-visible { outline: 2px solid var(--green); outline-offset: -4px; }
.btn--accent {
  background: var(--green);
  border-color: var(--green);
  color: var(--ink-950);
  font-weight: 700;
}
.btn--accent:hover { background: #37F894; border-color: #37F894; color: var(--ink-950); }
.btn--ghost { background: transparent; }

/* 8. Tags ---------------------------------------------------------------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 1px solid rgba(0, 230, 118, .35);
  background: rgba(0, 230, 118, .1);
  color: var(--green);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  line-height: 1.6;
}
.tag--orange { border-color: rgba(255, 109, 0, .42); background: rgba(255, 109, 0, .12); color: var(--orange); }
.tag--amber { border-color: rgba(255, 194, 74, .42); background: rgba(255, 194, 74, .12); color: var(--amber); }
.tag--muted { border-color: var(--steel); background: rgba(42, 63, 99, .42); color: var(--slate); }

/* 9. Data graphics ------------------------------------------------------- */
.stat { display: flex; flex-direction: column; gap: 4px; }
.stat__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(28px, 4.4vw, 48px);
  font-weight: 700;
  line-height: 1;
  color: var(--green);
}
.stat__label { font-size: 13px; letter-spacing: .06em; color: var(--slate); }
.stat--orange .stat__value { color: var(--orange); }
.stat--amber .stat__value { color: var(--amber); }

.data-bar {
  position: relative;
  width: 100%;
  height: 8px;
  background: rgba(42, 63, 99, .55);
  overflow: hidden;
}
.data-bar__fill {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--green-dim), var(--green));
}
.data-bar--orange .data-bar__fill { background: linear-gradient(90deg, #A34600, var(--orange)); }

.data-ring {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 132px;
  height: 132px;
}
.data-ring svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}
.data-ring circle { fill: none; stroke-width: 8; }
.data-ring__track { stroke: rgba(42, 63, 99, .85); }
.data-ring__arc {
  stroke: var(--green);
  stroke-linecap: butt;
  transition: stroke-dashoffset .4s var(--ease), stroke .2s var(--ease);
}
.data-ring:hover .data-ring__arc { stroke: var(--orange); }
.data-ring__center {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  font-family: var(--font-mono);
}
.data-ring__num { font-size: 26px; font-weight: 700; line-height: 1; color: var(--white); }
.data-ring__unit { margin-top: 4px; font-size: 11px; letter-spacing: .1em; color: var(--slate); }

.data-table { font-size: 14px; }
.data-table th,
.data-table td {
  padding: 12px 10px;
  text-align: left;
  border-bottom: 1px solid var(--steel);
}
.data-table th {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--slate);
}
.data-table td.mono { color: var(--white); }
.data-table tbody tr:hover td { background: rgba(18, 58, 107, .42); }

.timeline { position: relative; padding-left: 26px; }
.timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--green), rgba(0, 230, 118, 0) 92%);
}
.timeline__item { position: relative; padding-bottom: 28px; }
.timeline__item:last-child { padding-bottom: 0; }
.timeline__marker {
  position: absolute;
  left: -26px;
  top: 6px;
  width: 14px;
  height: 14px;
  background: var(--ink-950);
  border: 2px solid var(--green);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}
.timeline__time {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--amber);
}

/* 10. Media -------------------------------------------------------------- */
.media {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: linear-gradient(135deg, var(--navy-800), var(--ink-950));
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}
.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.94) contrast(1.06);
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(118deg, rgba(0, 230, 118, .14), rgba(5, 11, 22, 0) 40%, rgba(5, 11, 22, .72) 100%);
  pointer-events: none;
}
.media__tag {
  position: absolute;
  left: 0;
  top: 0;
  z-index: 2;
  padding: 6px 12px;
  background: var(--orange);
  color: #0B0F17;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .1em;
}
.media__caption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--slate);
}
.media-grid { display: grid; gap: 20px; grid-template-columns: 1fr; }

/* 11. Breadcrumbs & FAQ -------------------------------------------------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--slate);
}
.breadcrumbs__link { border-bottom: 1px solid transparent; transition: color .18s var(--ease), border-color .18s var(--ease); }
.breadcrumbs__link:hover { color: var(--green); border-bottom-color: var(--green); }
.breadcrumbs__sep { color: var(--steel); }
.breadcrumbs [aria-current="page"] { color: var(--white); }

.faq { display: grid; }
.faq__item { border-top: 1px solid var(--steel); }
.faq__item:last-child { border-bottom: 1px solid var(--steel); }
.faq__q {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  min-height: 44px;
  padding: 18px 4px;
  text-align: left;
  font-size: 16px;
  font-weight: 600;
  color: var(--white);
  transition: color .18s var(--ease);
}
.faq__q::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--green);
  transition: transform .2s var(--ease), color .2s var(--ease);
}
.faq__q:hover { color: var(--green); }
.faq__q[aria-expanded="true"] { color: var(--green); }
.faq__q[aria-expanded="true"]::after { transform: rotate(45deg); color: var(--orange); }
.faq__a { padding: 0 4px 20px; font-size: 15px; color: var(--slate); }
.faq__a[hidden] { display: none; }

/* 12. Header / 侧边轨道 -------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 12px;
  padding: 10px 16px;
  background: rgba(5, 11, 22, .94);
  border-bottom: 1px solid var(--steel);
  backdrop-filter: blur(10px);
}
.brand {
  display: flex;
  flex: 1 1 auto;
  align-items: center;
  gap: 10px;
  min-width: 0;
}
.brand__mark {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  background: var(--green);
  color: var(--ink-950);
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 900;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
}
.brand__text { display: flex; flex-direction: column; min-width: 0; }
.brand__name {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: .06em;
  color: var(--white);
}
.brand__tagline {
  overflow: hidden;
  font-size: 11px;
  letter-spacing: .04em;
  color: var(--slate);
  white-space: nowrap;
  text-overflow: ellipsis;
}

.rail-status {
  display: flex;
  flex: 0 0 auto;
  align-items: baseline;
  gap: 6px;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--slate);
  white-space: nowrap;
}
.rail-status__value { color: var(--green); font-weight: 700; }

.nav-toggle {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 8px 12px;
  border: 1px solid var(--steel);
  background: rgba(18, 58, 107, .32);
  color: var(--white);
  font-size: 13px;
  letter-spacing: .08em;
  transition: border-color .18s var(--ease), color .18s var(--ease), background-color .18s var(--ease);
}
.nav-toggle:hover { border-color: var(--green); color: var(--green); }
.nav-toggle[aria-expanded="true"] { border-color: var(--green); color: var(--green); background: rgba(0, 230, 118, .1); }
.nav-toggle__bars { position: relative; display: block; width: 18px; height: 12px; }
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: transform .2s var(--ease), top .2s var(--ease);
}
.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { top: 10px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 5px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 5px; transform: rotate(-45deg); }

.site-nav {
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-height: 0;
  padding: 0 16px;
  overflow: hidden;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  background: linear-gradient(180deg, #08142B, #050B16);
  border-bottom: 1px solid var(--steel);
  transition: max-height .28s var(--ease), opacity .2s var(--ease), padding .28s var(--ease), visibility .28s var(--ease);
}
.site-header[data-open] .site-nav {
  max-height: min(74vh, 520px);
  padding: 14px 16px 18px;
  overflow-y: auto;
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}
.site-nav__list {
  display: flex;
  flex-direction: row;
  gap: 8px;
  padding-bottom: 10px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}
.site-nav__item { flex: 0 0 auto; scroll-snap-align: start; }
.site-nav__link {
  position: relative;
  isolation: isolate;
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 14px;
  border: 1px solid var(--steel);
  color: var(--slate);
  font-size: 13px;
  letter-spacing: .08em;
  white-space: nowrap;
  transition: color .18s var(--ease), border-color .18s var(--ease), transform .18s var(--ease);
}
.site-nav__link::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-color: transparent;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%);
  transition: background-color .18s var(--ease);
}
.site-nav__index { font-size: 10px; letter-spacing: .1em; color: var(--steel); }
.site-nav__label { display: block; }
.site-nav__link:hover { color: var(--white); border-color: var(--green); transform: translateY(-2px); }
.site-nav__link:hover::before { background-color: rgba(18, 58, 107, .72); }
.site-nav__link[aria-current="page"] { color: var(--ink-950); border-color: var(--green); font-weight: 700; }
.site-nav__link[aria-current="page"]::before { background-color: var(--green); }
.site-nav__link[aria-current="page"] .site-nav__index { color: rgba(5, 11, 22, .55); }
.site-nav__link:focus-visible { outline: 2px solid var(--green); outline-offset: -3px; }
.site-nav__cta { align-self: stretch; }

/* 13. Footer ------------------------------------------------------------- */
.site-footer {
  position: relative;
  margin-top: 88px;
  background: linear-gradient(180deg, #071229 0%, var(--navy-900) 100%);
  border-top: 1px solid var(--steel);
  color: var(--white);
}
.site-footer::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 5px;
  background: linear-gradient(90deg, var(--green) 0 22%, var(--orange) 22% 34%, var(--steel) 34% 100%);
}
.site-footer__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding: 56px 20px 32px;
}
.site-footer__brand { display: flex; flex-direction: column; gap: 8px; align-items: flex-start; }
.site-footer__name {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 900;
  letter-spacing: .04em;
}
.site-footer__tagline { font-size: 13px; color: var(--slate); }
.site-footer__round { font-size: 12px; letter-spacing: .1em; color: var(--green); }
.site-footer__col { display: flex; flex-direction: column; gap: 12px; }
.site-footer__title {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--amber);
}
.site-footer__list { display: flex; flex-direction: column; gap: 4px; }
.site-footer__link {
  position: relative;
  display: inline-block;
  padding: 5px 0;
  color: var(--slate);
  font-size: 15px;
  transition: color .18s var(--ease);
}
.site-footer__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 2px;
  width: 100%;
  height: 1px;
  background: var(--green);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .22s var(--ease);
}
.site-footer__link:hover { color: var(--white); }
.site-footer__link:hover::after { transform: scaleX(1); }
.site-footer__link[aria-current="page"] { color: var(--green); }

.contact-list { display: flex; flex-direction: column; gap: 12px; }
.contact-list__item {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 14px;
}
.contact-list__key {
  flex: 0 0 40px;
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--steel);
  text-transform: uppercase;
}
.contact-list__value { color: var(--white); word-break: break-word; }
.contact-list__item--note .contact-list__value { font-size: 13px; line-height: 1.7; color: var(--slate); }
.copy-btn {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  padding: 4px 10px;
  border: 1px dashed var(--steel);
  color: var(--slate);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  transition: border-color .18s var(--ease), color .18s var(--ease), background-color .18s var(--ease);
}
.copy-btn:hover { border-color: var(--green); color: var(--green); }
.copy-btn[data-copied="true"] {
  border-style: solid;
  border-color: var(--green);
  background: rgba(0, 230, 118, .12);
  color: var(--green);
}
.site-footer__base {
  max-width: var(--shell-max);
  margin-inline: auto;
  padding: 18px 20px 32px;
  border-top: 1px solid rgba(42, 63, 99, .7);
}
.site-footer__legal { font-size: 12.5px; letter-spacing: .04em; color: var(--slate); }

/* 14. 注入式交互元素 ----------------------------------------------------- */
.scroll-meter {
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  height: 2px;
  z-index: 120;
  pointer-events: none;
  background: rgba(42, 63, 99, .45);
}
.scroll-meter__fill {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--green), var(--amber) 70%, var(--orange));
  transition: width .12s linear;
}
.to-top {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 90;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border: 1px solid var(--steel);
  background: var(--navy-900);
  color: var(--white);
  font-size: 18px;
  line-height: 1;
  clip-path: polygon(10px 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%, 0 10px);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity .2s var(--ease), transform .2s var(--ease), visibility .2s var(--ease), background-color .2s var(--ease), color .2s var(--ease);
}
.to-top[data-visible="true"] { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { background: var(--green); color: var(--ink-950); }
.to-top:focus-visible { outline: 2px solid var(--green); outline-offset: -4px; }

/* 15. 平板 --------------------------------------------------------------- */
@media (min-width: 640px) {
  .shell { padding-inline: 28px; }
  .section { padding-block: 88px; }
  .section--tight { padding-block: 56px; }
  .cut-panel { padding: 30px; }
  .media-grid { grid-template-columns: repeat(2, 1fr); }
  .site-footer__inner { grid-template-columns: repeat(2, 1fr); }
  .site-footer__brand { grid-column: 1 / -1; }
}
@media (max-width: 479px) {
  .brand__tagline { display: none; }
  .nav-toggle__label { display: none; }
}

/* 16. 桌面端：左侧常驻轨道 ---------------------------------------------- */
@media (min-width: 1024px) {
  body { padding-left: var(--rail-w); }

  .shell { padding-inline: 48px; }
  .section { padding-block: 120px; }
  .section--tight { padding-block: 72px; }
  .grid--5-7 { grid-template-columns: 5fr 7fr; }
  .grid--4-8 { grid-template-columns: 4fr 8fr; }
  .grid--halves { grid-template-columns: 1fr 1fr; }
  .media-grid { grid-template-columns: repeat(12, 1fr); gap: 24px; }
  .media-grid__item--main { grid-column: span 7; }
  .media-grid__item--side { grid-column: span 5; }

  .site-header {
    position: fixed;
    inset: 0 auto 0 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: var(--rail-w);
    padding: 18px 0 16px;
    background: linear-gradient(180deg, #08142B 0%, #050B16 58%, #061225 100%);
    border-bottom: 0;
    border-right: 1px solid var(--steel);
    backdrop-filter: none;
    overflow-x: hidden;
    overflow-y: auto;
  }
  .site-header::before {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    width: 1px;
    height: 100%;
    background: linear-gradient(180deg, rgba(0, 230, 118, 0), rgba(0, 230, 118, .45) 32%, rgba(0, 230, 118, 0) 86%);
    pointer-events: none;
  }
  .brand {
    flex: 0 0 auto;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 0 8px 18px;
    border-bottom: 1px solid var(--steel);
  }
  .brand__mark { width: 40px; height: 40px; font-size: 20px; }
  .brand__text { align-items: center; }
  .brand__name {
    writing-mode: vertical-rl;
    font-size: 13px;
    letter-spacing: .22em;
    padding-top: 4px;
  }
  .brand__tagline { display: none; }

  .nav-toggle { display: none; }

  .site-nav {
    position: static;
    flex: 1 1 auto;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
    max-height: none;
    padding: 16px 10px;
    overflow: visible;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    background: none;
    border-bottom: 0;
    transition: none;
  }
  .site-nav__list {
    flex-direction: column;
    gap: 6px;
    padding-bottom: 0;
    overflow: visible;
  }
  .site-nav__item { flex: 1 1 auto; }
  .site-nav__link {
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 11px 4px;
    font-size: 12px;
    letter-spacing: .06em;
    white-space: normal;
    word-break: keep-all;
  }
  .site-nav__index { font-size: 10px; }
  .site-nav__cta {
    align-self: stretch;
    margin-top: 14px;
    padding: 12px 6px;
    font-size: 12px;
    letter-spacing: .04em;
    line-height: 1.4;
  }
  .rail-status {
    flex: 0 0 auto;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 14px 4px 0;
    border-top: 1px solid var(--steel);
    font-size: 10px;
  }
  .rail-status__value { font-size: 12px; }

  .scroll-meter { left: var(--rail-w); }

  .site-footer__inner {
    grid-template-columns: 1.5fr 1fr 1fr 1.6fr;
    gap: 48px;
    padding: 72px 48px 40px;
  }
  .site-footer__brand { grid-column: auto; }
  .site-footer__base { padding: 20px 48px 36px; }
}

/* 17. 无障碍：减少动效 --------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
  .cut-panel:hover,
  .btn:hover,
  .site-nav__link:hover { transform: none; }
}