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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 130px;
}

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

ul, ol { list-style: none; }

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

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

a { color: inherit; }

/* ================= 2. 变量 ================= */
:root {
  --c-deep: #04121F;
  --c-hull: #071B2E;
  --c-panel: #0B2740;
  --c-line: #12405C;
  --c-cyan: #00E5C4;
  --c-cyan-soft: #7FFFE6;
  --c-orange: #FF6A2B;
  --c-amber: #FFB020;
  --c-violet: #7C5CFF;
  --c-text: #E6F4FF;
  --c-soft: #B9CFDF;
  --c-muted: #8FA9BF;

  --shell: 1280px;
  --gutter: clamp(18px, 4vw, 44px);
  --gap: clamp(18px, 2.4vw, 32px);

  --font-display: "Arial Narrow", "Helvetica Neue Condensed", "Helvetica Neue", Helvetica, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-serif: Georgia, "Times New Roman", "Songti SC", "Noto Serif SC", "Source Han Serif SC", serif;
  --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", "Courier New", monospace;

  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ================= 3. 基础排版 ================= */
body {
  min-height: 100vh;
  background: var(--c-deep);
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.7;
  letter-spacing: .01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: .55;
  background-image:
    radial-gradient(1100px 620px at 88% -12%, rgba(0, 229, 196, .10), transparent 62%),
    radial-gradient(900px 520px at 4% 16%, rgba(124, 92, 255, .09), transparent 66%),
    linear-gradient(to right, rgba(18, 64, 92, .38) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(18, 64, 92, .38) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 96px 96px, 96px 96px;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: .06em;
  text-wrap: balance;
}

h1 { font-size: clamp(34px, 5vw, 48px); }
h2 { font-size: clamp(26px, 3.4vw, 36px); }
h3 { font-size: clamp(20px, 2.2vw, 24px); }

p { text-wrap: pretty; }

a {
  color: var(--c-cyan);
  text-decoration: none;
  transition: color .22s var(--ease), opacity .22s var(--ease);
}

a:hover { color: var(--c-cyan-soft); }

:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
  border-radius: 2px;
}

.mono { font-family: var(--font-mono); }
.muted { color: var(--c-muted); }
.accent { color: var(--c-cyan); }

.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;
}

/* ================= 4. 容器与分区 ================= */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.shell--wide { max-width: 1520px; }

.section {
  position: relative;
  padding-block: clamp(52px, 7vw, 104px);
}

.section--tight { padding-block: clamp(30px, 4vw, 56px); }
.section--hull { background: var(--c-hull); }
.section--panel { background: var(--c-panel); }
.section--edge { border-top: 1px solid var(--c-line); }

/* ================= 5. 网格 ================= */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gap);
}

.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-12 { grid-column: span 12; }

.offset-1 { grid-column-start: 2; }
.offset-2 { grid-column-start: 3; }
.offset-3 { grid-column-start: 4; }

.split {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  gap: clamp(24px, 4vw, 64px);
  align-items: start;
}

.split--reverse { grid-template-columns: minmax(0, 1fr) minmax(0, 1.35fr); }

.stack { display: grid; gap: var(--gap); }
.stack--tight { gap: 12px; }
.stack--loose { gap: clamp(32px, 5vw, 72px); }

/* ================= 6. 排版组件 ================= */
.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.kicker::before {
  content: "";
  width: 22px;
  height: 1px;
  background: linear-gradient(90deg, var(--c-cyan), transparent);
}

.display-xl {
  font-family: var(--font-display);
  font-size: clamp(48px, 9vw, 120px);
  font-weight: 700;
  line-height: .92;
  letter-spacing: .02em;
  text-transform: uppercase;
}

.display-l {
  font-family: var(--font-display);
  font-size: clamp(36px, 5.6vw, 68px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: .04em;
  text-transform: uppercase;
}

.serif-lead {
  font-family: var(--font-serif);
  font-size: clamp(19px, 2vw, 24px);
  line-height: 1.62;
  color: var(--c-text);
  opacity: .92;
}

.lead {
  font-size: clamp(16.5px, 1.5vw, 18.5px);
  line-height: 1.75;
  color: var(--c-soft);
}

.rule {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--c-line), rgba(18, 64, 92, 0));
}

/* ================= 7. 按钮 ================= */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px 11px 24px;
  border: 1px solid var(--c-line);
  border-radius: 2px;
  background: transparent;
  color: var(--c-text);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  text-decoration: none;
  cursor: pointer;
  transition: background .24s var(--ease), color .24s var(--ease), border-color .24s var(--ease), transform .24s var(--ease);
}

.btn::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--c-line);
  transition: background .24s var(--ease);
}

.btn:hover { transform: translateY(-1px); }

.btn--accent {
  background: var(--c-orange);
  border-color: var(--c-orange);
  color: #08131F;
  font-weight: 700;
}

.btn--accent::before { background: #08131F; opacity: .35; }
.btn--accent:hover { background: #FF8149; border-color: #FF8149; color: #08131F; }

.btn--ghost {
  border-color: rgba(0, 229, 196, .45);
  background: rgba(0, 229, 196, .06);
  color: var(--c-cyan);
}

.btn--ghost::before { background: var(--c-cyan); }
.btn--ghost:hover { background: rgba(0, 229, 196, .16); color: var(--c-cyan-soft); }

.btn--quiet { border-color: var(--c-line); color: var(--c-muted); }
.btn--quiet::before { background: var(--c-line); }
.btn--quiet:hover { color: var(--c-text); border-color: var(--c-cyan); }

.btn--sm { padding: 7px 14px 7px 18px; font-size: 11px; }
.btn--block { width: 100%; }

/* ================= 8. 头部 ================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -120px;
  z-index: 90;
  padding: 12px 20px;
  background: var(--c-cyan);
  color: #04121F;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .12em;
  text-decoration: none;
  transition: top .22s var(--ease);
}

.skip-link:focus { top: 12px; color: #04121F; }

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 95;
  pointer-events: none;
}

.scroll-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--c-cyan), var(--c-violet) 55%, var(--c-orange));
}

.topline {
  background: var(--c-hull);
  border-bottom: 1px solid var(--c-line);
}

.topline__inner {
  max-width: var(--shell);
  margin-inline: auto;
  padding: 9px var(--gutter);
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
}

.topline__brand {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--c-cyan-soft);
}

.topline__tagline {
  font-family: var(--font-serif);
  font-size: 14px;
  color: var(--c-muted);
}

.status-strip {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
}

.status-chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 4px 11px;
  border: 1px solid var(--c-line);
  border-radius: 999px;
  background: rgba(11, 39, 64, .62);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--c-muted);
  white-space: nowrap;
}

.status-chip--live { color: var(--c-cyan); border-color: rgba(0, 229, 196, .38); }
.status-chip--time { color: var(--c-muted); }

.status-chip__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-cyan);
  box-shadow: 0 0 0 0 rgba(0, 229, 196, .55);
  animation: chip-pulse 2.6s var(--ease) infinite;
}

@keyframes chip-pulse {
  0%   { box-shadow: 0 0 0 0 rgba(0, 229, 196, .5); }
  70%  { box-shadow: 0 0 0 7px rgba(0, 229, 196, 0); }
  100% { box-shadow: 0 0 0 0 rgba(0, 229, 196, 0); }
}

.topline__cta { flex: none; }

.navbar {
  background: rgba(4, 18, 31, .93);
  border-bottom: 1px solid var(--c-line);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.navbar__inner {
  max-width: var(--shell);
  margin-inline: auto;
  padding: 13px var(--gutter);
  display: flex;
  align-items: center;
  gap: 26px;
}

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

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

.brand__mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  flex: none;
  border: 1px solid var(--c-cyan);
  background: linear-gradient(140deg, rgba(0, 229, 196, .2), rgba(0, 229, 196, 0) 72%);
  color: var(--c-cyan);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .06em;
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
}

.brand__text { display: grid; gap: 1px; }

.brand__name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: .16em;
  line-height: 1.15;
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: .3em;
  color: var(--c-muted);
  text-transform: uppercase;
}

.nav-toggle {
  display: none;
  margin-left: auto;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: 1px solid var(--c-line);
  border-radius: 2px;
  background: rgba(11, 39, 64, .82);
  color: var(--c-text);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  cursor: pointer;
}

.nav-toggle__bars {
  position: relative;
  width: 16px;
  height: 10px;
  flex: none;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 1.5px;
  background: var(--c-cyan);
  transition: transform .25s var(--ease), top .25s var(--ease);
}

.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { top: 8px; }

.site-header[data-open] .nav-toggle__bars::before { top: 4px; transform: rotate(45deg); }
.site-header[data-open] .nav-toggle__bars::after { top: 4px; transform: rotate(-45deg); }

.primary-nav { margin-left: auto; }

.primary-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link {
  position: relative;
  display: block;
  padding: 10px 14px;
  color: var(--c-muted);
  font-family: var(--font-display);
  font-size: 13.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  text-decoration: none;
  transition: color .22s var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 3px;
  height: 1px;
  background: var(--c-cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .28s var(--ease), background .28s var(--ease);
}

.nav-link:hover { color: var(--c-text); }
.nav-link:hover::after { transform: scaleX(1); }

.nav-link[aria-current="page"] { color: var(--c-cyan); }
.nav-link[aria-current="page"]::after { transform: scaleX(1); background: var(--c-orange); }

.to-top {
  position: fixed;
  right: 20px;
  bottom: 62px;
  z-index: 70;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border: 1px solid var(--c-line);
  border-radius: 2px;
  background: rgba(11, 39, 64, .92);
  color: var(--c-cyan);
  font-size: 17px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .28s var(--ease), transform .28s var(--ease), visibility .28s linear, border-color .28s var(--ease);
}

.to-top[data-visible] { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { border-color: var(--c-cyan); }

/* ================= 9. 页脚 ================= */
.site-footer {
  position: relative;
  z-index: 1;
  background: linear-gradient(180deg, var(--c-hull), var(--c-deep) 82%);
  border-top: 1px solid var(--c-line);
}

.footer-inner {
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(44px, 6vw, 84px) var(--gutter) 0;
}

.footer-lead {
  display: grid;
  gap: 14px;
  max-width: 780px;
  padding-bottom: clamp(30px, 4vw, 54px);
  border-bottom: 1px solid var(--c-line);
}

.footer-lead__title {
  font-family: var(--font-display);
  font-size: clamp(28px, 4.4vw, 52px);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.footer-lead__note {
  font-family: var(--font-serif);
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.65;
  color: var(--c-soft);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: clamp(22px, 3vw, 44px);
  padding: clamp(30px, 4vw, 54px) 0;
}

.footer-block {
  display: grid;
  gap: 12px;
  align-content: start;
}

.footer-block__title {
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(18, 64, 92, .75);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.footer-block__brand {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.footer-block__text {
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--c-muted);
}

.footer-links { display: grid; gap: 10px; }

.footer-links a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--c-muted);
  font-size: 14.5px;
  text-decoration: none;
  transition: color .22s var(--ease), transform .22s var(--ease);
}

.footer-links a::before {
  content: "";
  width: 6px;
  height: 1px;
  background: var(--c-line);
  transition: width .22s var(--ease), background .22s var(--ease);
}

.footer-links a:hover { color: var(--c-cyan); transform: translateX(3px); }
.footer-links a:hover::before { width: 14px; background: var(--c-cyan); }

.footer-contact { display: grid; gap: 12px; }
.footer-contact li { display: grid; gap: 3px; }

.footer-contact__k {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.footer-contact__v {
  font-family: var(--font-mono);
  font-size: 13.5px;
  color: var(--c-text);
  word-break: break-word;
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 26px;
  padding: 22px 0 30px;
  border-top: 1px solid var(--c-line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--c-muted);
}

.footer-meta__icp { color: var(--c-cyan-soft); }
.footer-meta__note { margin-left: auto; }

.status-bar {
  position: sticky;
  bottom: 0;
  background: rgba(11, 39, 64, .96);
  border-top: 1px solid var(--c-line);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.status-bar__inner {
  max-width: var(--shell);
  margin-inline: auto;
  padding: 10px var(--gutter);
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--c-muted);
}

.status-bar__zone { color: var(--c-cyan); }
.status-bar__sep { color: var(--c-line); }
.status-bar__item .mono { color: var(--c-cyan-soft); }

/* ================= 10. 内容组件 ================= */
.panel {
  position: relative;
  padding: clamp(20px, 2.6vw, 34px);
  background: linear-gradient(160deg, var(--c-panel), rgba(7, 27, 46, .55));
  border-top: 1px solid rgba(0, 229, 196, .32);
}

.panel--quiet {
  background: rgba(11, 39, 64, .5);
  border-top-color: var(--c-line);
}

.panel__label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.index-list { display: grid; }

.index-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 16px;
  align-items: baseline;
  padding: 16px 4px;
  border-bottom: 1px solid rgba(18, 64, 92, .55);
  transition: background .24s var(--ease), padding-left .24s var(--ease);
}

.index-item:hover { background: rgba(0, 229, 196, .05); padding-left: 14px; }

.index-item__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--c-cyan);
}

.index-item__title { font-size: 17px; color: var(--c-text); }

.index-item__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-muted);
  white-space: nowrap;
}

.timeline {
  position: relative;
  padding-left: 26px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--c-cyan), var(--c-line) 58%, rgba(18, 64, 92, 0));
}

.timeline__node {
  position: relative;
  padding-bottom: 26px;
}

.timeline__node::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 8px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--c-deep);
  border: 1px solid var(--c-cyan);
}

.timeline__node--flag::before { background: var(--c-orange); border-color: var(--c-orange); }

.timeline__time {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--c-cyan);
}

.timeline__title { margin-top: 2px; font-size: 16.5px; }
.timeline__note { font-size: 14.5px; color: var(--c-muted); }

.metric { display: grid; gap: 4px; }

.metric__value {
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1;
  color: var(--c-cyan);
}

.metric__label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.metric--accent .metric__value { color: var(--c-orange); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid currentColor;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.tag--cyan { color: var(--c-cyan); }
.tag--orange { color: var(--c-orange); }
.tag--amber { color: var(--c-amber); }
.tag--violet { color: var(--c-violet); }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.breadcrumb__item { display: inline-flex; align-items: center; gap: 8px; }

.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: var(--c-line);
}

.breadcrumb a { color: var(--c-muted); }
.breadcrumb a:hover { color: var(--c-cyan); }
.breadcrumb [aria-current="page"] { color: var(--c-cyan); }

.rail {
  position: sticky;
  top: 132px;
  display: grid;
  gap: 10px;
  padding: 18px 0;
}

.rail__title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.rail__list {
  display: grid;
  gap: 2px;
  border-left: 1px solid var(--c-line);
}

.rail__link {
  position: relative;
  display: block;
  padding: 7px 0 7px 14px;
  font-size: 14px;
  color: var(--c-muted);
  text-decoration: none;
  transition: color .22s var(--ease), padding-left .22s var(--ease);
}

.rail__link::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 50%;
  width: 2px;
  height: 70%;
  background: var(--c-cyan);
  transform: translateY(-50%) scaleY(0);
  transition: transform .24s var(--ease);
}

.rail__link:hover { color: var(--c-text); padding-left: 18px; }
.rail__link[aria-current="true"] { color: var(--c-cyan); padding-left: 18px; }
.rail__link[aria-current="true"]::before { transform: translateY(-50%) scaleY(1); }

.faq {
  display: grid;
  border-top: 1px solid var(--c-line);
}

.faq__item { border-bottom: 1px solid rgba(18, 64, 92, .6); }

.faq__q {
  display: flex;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 4px;
  border: 0;
  background: none;
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: 17px;
  text-align: left;
  cursor: pointer;
  transition: color .22s var(--ease);
}

.faq__q:hover { color: var(--c-cyan); }

.faq__icon {
  position: relative;
  flex: none;
  width: 16px;
  height: 16px;
}

.faq__icon::before,
.faq__icon::after {
  content: "";
  position: absolute;
  background: var(--c-cyan);
  transition: transform .24s var(--ease), opacity .24s var(--ease);
}

.faq__icon::before { left: 0; top: 7px; width: 100%; height: 2px; }
.faq__icon::after { top: 0; left: 7px; width: 2px; height: 100%; }

.faq__q[aria-expanded="true"] .faq__icon::after { transform: scaleY(0); opacity: 0; }

.faq__a {
  display: grid;
  gap: 8px;
  padding: 0 4px 22px;
  font-size: 16px;
  color: var(--c-soft);
}

.faq__a[hidden] { display: none; }

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  border-bottom: 1px solid var(--c-line);
}

.tabs__btn {
  padding: 10px 16px;
  border: 0;
  border-bottom: 2px solid transparent;
  background: none;
  color: var(--c-muted);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .12em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color .22s var(--ease), border-color .22s var(--ease);
}

.tabs__btn:hover { color: var(--c-text); }
.tabs__btn[aria-selected="true"] { color: var(--c-cyan); border-bottom-color: var(--c-cyan); }

.tabs__panel { padding-top: 22px; }
.tabs__panel[hidden] { display: none; }

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.filter-btn {
  padding: 7px 14px;
  border: 1px solid var(--c-line);
  border-radius: 2px;
  background: rgba(7, 27, 46, .6);
  color: var(--c-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  cursor: pointer;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}

.filter-btn:hover { color: var(--c-text); border-color: rgba(0, 229, 196, .5); }
.filter-btn[aria-pressed="true"] {
  background: rgba(0, 229, 196, .14);
  border-color: var(--c-cyan);
  color: var(--c-cyan);
}

[data-filter-item][hidden] { display: none; }

.compare {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--c-line);
}

.compare__col {
  padding: clamp(20px, 2.6vw, 34px);
  background: var(--c-hull);
}

.compare__col--alt { background: var(--c-panel); }

.compare__head {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.figure { display: grid; gap: 12px; }

.figure__frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(150deg, var(--c-panel), var(--c-deep) 72%);
  border-top: 1px solid rgba(0, 229, 196, .3);
}

.figure__frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .55;
  background: repeating-linear-gradient(90deg, rgba(18, 64, 92, .55) 0 1px, transparent 1px 84px);
}

.figure__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure__ph {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: rgba(143, 169, 191, .72);
}

.figure__caption {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--c-muted);
}

.figure--wide .figure__frame { aspect-ratio: 21 / 9; }
.figure--standard .figure__frame { aspect-ratio: 16 / 9; }
.figure--tall .figure__frame { aspect-ratio: 4 / 5; }

.copy-field {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  background: rgba(7, 27, 46, .72);
  border-left: 2px solid var(--c-cyan);
}

.copy-field__value {
  font-family: var(--font-mono);
  font-size: 14.5px;
  color: var(--c-text);
  word-break: break-all;
}

.copy-field__btn {
  margin-left: auto;
  flex: none;
  padding: 6px 12px;
  border: 1px solid var(--c-line);
  border-radius: 2px;
  background: transparent;
  color: var(--c-cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  cursor: pointer;
  transition: background .2s var(--ease), border-color .2s var(--ease);
}

.copy-field__btn:hover { background: rgba(0, 229, 196, .12); border-color: var(--c-cyan); }

.aside-note {
  padding-left: 16px;
  border-left: 2px solid var(--c-orange);
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--c-muted);
}

.reveal { transition: opacity .7s var(--ease), transform .7s var(--ease); }
.js-ready .reveal { opacity: 0; transform: translateY(20px); }
.js-ready .reveal.is-visible { opacity: 1; transform: none; }

/* ================= 11. 响应式 ================= */
@media (max-width: 1080px) {
  .topline__tagline { display: none; }
  .rail { display: none; }
}

@media (max-width: 1024px) {
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .span-3, .span-4, .span-5, .span-6, .span-7, .span-8, .span-12 { grid-column: span 6; }
  .offset-1, .offset-2, .offset-3 { grid-column-start: auto; }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 960px) {
  html { scroll-padding-top: 96px; }

  .nav-toggle { display: inline-flex; }
  .primary-nav { margin-left: 0; }

  .primary-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    max-height: calc(100vh - 110px);
    overflow: auto;
    padding: 8px var(--gutter) 22px;
    background: var(--c-panel);
    border-top: 1px solid var(--c-line);
    border-bottom: 1px solid var(--c-line);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity .25s var(--ease), transform .25s var(--ease), visibility .25s linear;
  }

  .site-header[data-open] .primary-nav {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

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

  .nav-link {
    padding: 14px 8px;
    border-bottom: 1px solid rgba(18, 64, 92, .6);
    font-size: 15px;
  }

  .nav-link::after { display: none; }

  .nav-link[aria-current="page"] {
    background: linear-gradient(90deg, rgba(0, 229, 196, .16), rgba(0, 229, 196, 0));
    border-bottom-color: rgba(0, 229, 196, .5);
  }

  .split, .split--reverse { grid-template-columns: 1fr; }
  .compare { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .topline__tagline,
  .status-strip { display: none; }
  .topline__cta { margin-left: auto; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-meta__note { margin-left: 0; }
  .to-top { right: 14px; bottom: 58px; }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .grid-12 { grid-template-columns: 1fr; }
  .span-3, .span-4, .span-5, .span-6, .span-7, .span-8, .span-12 { grid-column: span 1; }
  .index-item { grid-template-columns: auto minmax(0, 1fr); }
  .index-item__meta { grid-column: 2; }
}

/* ================= 12. 动效与无障碍 ================= */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  .js-ready .reveal { opacity: 1; transform: none; }
  .to-top { transform: none; }
}