/* ============================================================
   星空看台 · /assets/site.css
   共享外壳层：reset / 变量 / 中文排版 / 头部 / 页脚 / 通用组件
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 118px;
}

body { margin: 0; }

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
[hidden] { display: none !important; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #05070F;
  --panel: #0B1220;
  --panel-2: #1A2436;
  --line: #22304A;
  --cyan: #35E7D2;
  --purple: #8A6BFF;
  --orange: #FF7A3D;
  --red: #FF3B5C;
  --white: #F2F5FA;
  --muted: #A9B4C7;

  --mono: ui-monospace, "JetBrains Mono", "IBM Plex Mono", Consolas, monospace;
  --cond: "Archivo Narrow", "Oswald", "HarmonyOS Sans Condensed", sans-serif;
  --sans: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;

  --skew: -3deg;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 6px 22px rgba(0, 0, 0, .45);
  --shadow-soft: 0 4px 14px rgba(0, 0, 0, .32);
  --maxw: 1240px;
  --header-offset: 106px;
  --ease: cubic-bezier(.2, .7, .3, 1);
}

/* ---------- 3. 基础排版与画布 ---------- */
body {
  min-height: 100vh;
  padding-top: var(--header-offset);
  overflow-x: hidden;
  color: var(--white);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.85;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  background-color: var(--ink);
  background-image:
    radial-gradient(circle at 14% 3%, rgba(138, 107, 255, .18), transparent 40%),
    radial-gradient(circle at 86% 0%, rgba(53, 231, 210, .13), transparent 36%),
    radial-gradient(rgba(242, 245, 250, .085) 1px, transparent 1.4px),
    radial-gradient(rgba(53, 231, 210, .09) 1px, transparent 1.4px);
  background-size: auto, auto, 170px 170px, 260px 260px;
  background-position: 0 0, 0 0, 0 0, 80px 120px;
  background-repeat: no-repeat, no-repeat, repeat, repeat;
}

::selection { background: rgba(53, 231, 210, .3); color: #04120F; }

#main-content { scroll-margin-top: 118px; }
#main-content:focus { outline: none; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

/* ---------- 4. skip link ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 50%;
  z-index: 999;
  transform: translate(-50%, -160%);
  padding: 10px 18px;
  border: 1px solid rgba(53, 231, 210, .5);
  border-radius: 999px;
  background: rgba(11, 18, 32, .96);
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: .08em;
  transition: transform .24s var(--ease);
}
.skip-link:focus { transform: translate(-50%, 0); }

/* ---------- 5. 悬浮胶囊头部 ---------- */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 120;
  padding: 14px clamp(14px, 3vw, 34px);
  transition: padding .3s var(--ease);
}
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0;
  background: linear-gradient(180deg, rgba(5, 7, 15, .94), rgba(5, 7, 15, 0));
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  transition: opacity .3s var(--ease);
}
.site-header[data-condensed]::before { opacity: 1; }
.site-header[data-condensed] { padding-top: 10px; padding-bottom: 10px; }

.site-header__inner {
  position: relative;
  z-index: 1;
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.nav-island {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px 7px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(11, 18, 32, .74);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  box-shadow: 0 6px 18px rgba(5, 7, 15, .55);
  transition: padding .3s var(--ease), background .3s var(--ease), border-color .3s var(--ease);
}
.site-header[data-condensed] .nav-island {
  padding: 5px 10px 5px 8px;
  background: rgba(11, 18, 32, .88);
  border-color: #2A3A58;
}
.nav-island--menu { padding: 7px 8px; }

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 3px 8px 3px 2px;
  border-radius: 999px;
}
.brand__mark {
  flex: 0 0 auto;
  width: 22px; height: 22px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background:
    radial-gradient(circle at 32% 30%, var(--cyan), transparent 58%),
    radial-gradient(circle at 70% 72%, var(--purple), transparent 60%),
    #0B1220;
  box-shadow: 0 0 14px rgba(53, 231, 210, .35);
}
.brand__text { display: flex; flex-direction: column; line-height: 1.12; }
.brand__name { font-size: 15px; font-weight: 700; letter-spacing: .02em; }
.brand__sub {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .08em;
  color: var(--muted);
  transition: opacity .28s var(--ease), transform .28s var(--ease);
}
.site-header[data-condensed] .brand__sub { opacity: 0; transform: translateY(-5px); }

/* 主导航 */
.site-nav__list { display: flex; align-items: center; gap: 2px; }
.site-nav__list a {
  display: inline-block;
  padding: 8px 13px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 14px;
  line-height: 1.4;
  color: var(--muted);
  white-space: nowrap;
  transition: color .2s var(--ease), background .2s var(--ease), border-color .2s var(--ease);
}
.site-nav__list a:hover { color: var(--white); background: rgba(138, 107, 255, .16); }
.site-nav__list a[aria-current="page"] {
  color: var(--cyan);
  background: rgba(53, 231, 210, .12);
  border-color: rgba(53, 231, 210, .38);
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  height: 40px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(26, 36, 54, .6);
  color: var(--white);
  font-size: 13px;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.nav-toggle:hover { border-color: rgba(53, 231, 210, .45); background: rgba(53, 231, 210, .1); }
.nav-toggle__bars { display: inline-flex; flex-direction: column; gap: 4px; width: 16px; }
.nav-toggle__bars i {
  display: block;
  width: 100%; height: 1.5px;
  border-radius: 2px;
  background: var(--cyan);
  transition: transform .25s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:first-child { transform: translateY(2.75px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:last-child { transform: translateY(-2.75px) rotate(-45deg); }
.nav-toggle__label { letter-spacing: .06em; }

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(64px, 9vw, 120px);
  border-top: 1px solid var(--line);
  color: var(--white);
  background:
    radial-gradient(120% 90% at 10% 0%, rgba(138, 107, 255, .16), transparent 58%),
    radial-gradient(90% 70% at 92% 6%, rgba(53, 231, 210, .11), transparent 58%),
    var(--ink);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(53, 231, 210, .6), rgba(138, 107, 255, .6), transparent);
}

.site-footer__inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(38px, 5vw, 58px) clamp(18px, 4vw, 34px) 26px;
  display: grid;
  grid-template-columns: 1.5fr repeat(3, .9fr) 1.7fr;
  gap: 34px 26px;
}

.footer-brand__name { font-size: 21px; font-weight: 700; letter-spacing: .01em; }
.footer-brand__sub {
  margin-top: 6px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .09em;
  color: var(--cyan);
}
.footer-brand__note {
  margin-top: 14px;
  max-width: 30ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.footer-col__title {
  margin-bottom: 14px;
  font-family: var(--mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: .14em;
  color: var(--cyan);
}
.footer-col__list { display: grid; gap: 9px; }
.footer-col__list a {
  display: inline-block;
  font-size: 14.5px;
  color: var(--muted);
  transition: color .2s var(--ease), transform .2s var(--ease);
}
.footer-col__list a:hover { color: var(--white); transform: translateX(3px); }

.footer-contact { min-width: 0; }
.footer-contact__row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 12px;
  font-size: 14px;
  line-height: 1.75;
}
.footer-contact__label {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: #5D6E8C;
}
.footer-contact__value { color: var(--muted); overflow-wrap: anywhere; }
.footer-contact__note {
  margin-top: 6px;
  padding-left: 12px;
  border-left: 1px solid var(--line);
  font-size: 12.5px;
  line-height: 1.75;
  color: #7C8AA3;
}

.copy-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  max-width: 100%;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(26, 36, 54, .5);
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .03em;
  color: var(--white);
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.copy-chip:hover { border-color: rgba(53, 231, 210, .45); background: rgba(53, 231, 210, .08); }
.copy-chip__text { overflow-wrap: anywhere; }
.copy-chip__hint { flex: 0 0 auto; color: var(--cyan); white-space: nowrap; }

.footer-legal {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 16px clamp(18px, 4vw, 34px) 30px;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 18px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: #7C8AA3;
}
.footer-legal__meta { color: #5D6E8C; }

.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 28px);
  bottom: clamp(14px, 3vw, 28px);
  z-index: 110;
  display: grid;
  place-items: center;
  width: 46px; height: 46px;
  border: 1px solid rgba(53, 231, 210, .35);
  border-radius: 50%;
  background: rgba(11, 18, 32, .9);
  color: var(--cyan);
  font-size: 17px;
  line-height: 1;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  box-shadow: var(--shadow-soft);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: opacity .28s var(--ease), transform .28s var(--ease), visibility .28s var(--ease), border-color .2s var(--ease);
}
.to-top[data-visible] { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { border-color: var(--cyan); }

/* ---------- 7. 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(11, 18, 32, .6);
  color: var(--white);
  font-size: 15px;
  line-height: 1.4;
  text-align: center;
  transition: transform .2s var(--ease), background .2s var(--ease), border-color .2s var(--ease), color .2s var(--ease), box-shadow .2s var(--ease);
}
.btn:hover { transform: translateY(-2px); border-color: rgba(53, 231, 210, .45); background: rgba(53, 231, 210, .1); }
.btn--primary {
  border-color: transparent;
  background: linear-gradient(120deg, rgba(53, 231, 210, .95), rgba(53, 231, 210, .74));
  color: #04120F;
  font-weight: 600;
  box-shadow: 0 10px 26px rgba(53, 231, 210, .22);
}
.btn--primary:hover { background: linear-gradient(120deg, #48F4E0, rgba(53, 231, 210, .85)); border-color: transparent; }
.btn--ghost { background: transparent; }
.btn--ghost:hover { background: rgba(138, 107, 255, .14); border-color: rgba(138, 107, 255, .45); }
.btn--link {
  padding: 0;
  border: 0;
  border-radius: 0;
  background: none;
  color: var(--cyan);
}
.btn--link:hover { transform: none; background: none; color: #5FF3E2; }

/* ---------- 8. 布局与栅格 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 clamp(18px, 4vw, 34px);
}

.stack { display: grid; gap: clamp(20px, 3vw, 34px); }
.grid { display: grid; gap: clamp(18px, 3vw, 30px); }
.grid--split { grid-template-columns: 7fr 4fr; gap: clamp(18px, 3vw, 36px); }
.grid--half { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--third { grid-template-columns: repeat(3, minmax(0, 1fr)); }

/* ---------- 9. 面板与说明牌 ---------- */
.panel {
  position: relative;
  padding: clamp(20px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(11, 18, 32, .94), rgba(5, 7, 15, .62));
  box-shadow: var(--shadow);
}
.panel--flat { background: transparent; border-color: transparent; box-shadow: none; padding-left: 0; padding-right: 0; }
.panel--accent { border-color: rgba(53, 231, 210, .32); }
.panel--grid { overflow: hidden; }
.panel--grid::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  border-radius: inherit;
  opacity: .55;
  background-image:
    linear-gradient(rgba(34, 48, 74, .6) 1px, transparent 1px),
    linear-gradient(90deg, rgba(34, 48, 74, .6) 1px, transparent 1px);
  background-size: 46px 46px;
  -webkit-mask-image: linear-gradient(160deg, #000, transparent 76%);
  mask-image: linear-gradient(160deg, #000, transparent 76%);
}

.index-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 11px;
  border: 1px solid rgba(53, 231, 210, .3);
  border-radius: 999px;
  background: rgba(53, 231, 210, .08);
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.index-tag--purple {
  border-color: rgba(138, 107, 255, .34);
  background: rgba(138, 107, 255, .1);
  color: var(--purple);
}

.section-title {
  margin-bottom: 14px;
  color: var(--white);
  font-size: clamp(24px, 3.4vw, 38px);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -.01em;
}
.lede {
  max-width: 62ch;
  margin-bottom: 1.2em;
  color: var(--muted);
  font-size: 16.5px;
  line-height: 1.85;
}

.prose { font-size: 16.5px; line-height: 1.85; color: var(--white); }
.prose > * + * { margin-top: 1.2em; }
.prose h2 { font-size: clamp(24px, 3vw, 34px); line-height: 1.3; letter-spacing: -.01em; }
.prose h3 { font-size: clamp(19px, 2.2vw, 24px); line-height: 1.4; }
.prose ul, .prose ol { padding-left: 1.2em; }
.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }
.prose li { margin: .35em 0; }
.prose a { color: var(--cyan); border-bottom: 1px solid rgba(53, 231, 210, .35); }
.prose a:hover { border-bottom-color: var(--cyan); }
.prose strong { font-weight: 600; color: var(--white); }

/* ---------- 10. 数据组件 ---------- */
.stat { display: flex; flex-direction: column; gap: 6px; }
.stat__value {
  font-family: var(--cond);
  font-size: clamp(56px, 8vw, 118px);
  font-weight: 700;
  line-height: .92;
  letter-spacing: -.02em;
  color: var(--white);
  text-shadow: 0 0 18px rgba(53, 231, 210, .45);
  font-variant-numeric: tabular-nums;
}
.stat__label {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--muted);
}

.chip-row { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(26, 36, 54, .5);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .06em;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}
.chip:hover { color: var(--white); border-color: rgba(138, 107, 255, .45); }
.chip[aria-pressed="true"],
.chip.is-active {
  color: var(--cyan);
  border-color: rgba(53, 231, 210, .45);
  background: rgba(53, 231, 210, .12);
}

.divider-skew {
  height: 2px;
  margin: clamp(28px, 5vw, 56px) 0;
  border: 0;
  background: linear-gradient(90deg, transparent, rgba(53, 231, 210, .55), rgba(138, 107, 255, .55), transparent);
  transform: skewY(var(--skew));
  opacity: .75;
}

/* ---------- 11. 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 8px;
  margin-bottom: 22px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .06em;
}
.breadcrumbs a { color: var(--muted); transition: color .2s var(--ease); }
.breadcrumbs a:hover { color: var(--cyan); }
.breadcrumbs__sep { color: #3A4A66; }
.breadcrumbs [aria-current="page"] { color: var(--white); }

/* ---------- 12. 响应式图片容器（页面阶段放 img 用） ---------- */
.media-frame {
  position: relative;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    radial-gradient(120% 90% at 20% 0%, rgba(138, 107, 255, .18), transparent 60%),
    linear-gradient(150deg, #0B1220, #05070F 72%);
  box-shadow: var(--shadow);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, transparent 55%, rgba(5, 7, 15, .55));
}
.media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}
.media-frame--wide .media-frame__img { aspect-ratio: 21 / 9; }
.media-frame--tall .media-frame__img { aspect-ratio: 4 / 5; }
.media-frame--square .media-frame__img { aspect-ratio: 1 / 1; }
.media-frame__caption {
  position: relative;
  z-index: 1;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .06em;
}

/* ---------- 13. 滚动显现 ---------- */
html.has-reveal [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .42s var(--ease), transform .42s var(--ease);
  transition-delay: var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}
html.has-reveal [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* ---------- 14. 断点 ---------- */
@media (max-width: 1080px) {
  .grid--split { grid-template-columns: 1fr; }
  .site-footer__inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-contact { grid-column: 1 / -1; }
}

@media (max-width: 980px) {
  :root { --header-offset: 82px; }
  html { scroll-padding-top: 96px; }
  #main-content { scroll-margin-top: 96px; }

  .site-header { padding: 10px clamp(12px, 3vw, 20px); }
  .site-header[data-condensed] { padding-top: 8px; padding-bottom: 8px; }

  .nav-island--brand { padding: 6px 12px 6px 8px; }
  .nav-island--menu { position: static; padding: 6px; }

  .site-nav {
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    right: 0;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: rgba(11, 18, 32, .97);
    box-shadow: var(--shadow);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity .24s var(--ease), transform .24s var(--ease), visibility .24s var(--ease);
  }
  .site-nav[data-open] { opacity: 1; visibility: visible; transform: none; }
  .site-nav__list { flex-direction: column; align-items: stretch; gap: 2px; }
  .site-nav__list a { display: block; padding: 12px 14px; border-radius: 12px; font-size: 16px; }

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

@media (max-width: 820px) {
  .grid--half, .grid--third { grid-template-columns: 1fr; }
  .grid--third { gap: 18px; }
}

@media (max-width: 620px) {
  body { font-size: 15.5px; }
  .site-footer__inner { grid-template-columns: 1fr; gap: 28px; }
  .footer-contact { grid-column: auto; }
  .brand__sub { display: none; }
  .footer-legal { flex-direction: column; }
}

/* ---------- 15. 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  html.has-reveal [data-reveal] { opacity: 1; transform: none; }
}