/* ==========================================================================
   银河中心 · /assets/site.css
   共享外壳：reset / 设计变量 / 中文排版 / 命令栏头部 / 深空页脚 / 基础组件
   ========================================================================== */

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

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

body,
h1, h2, h3, h4, h5, h6,
p, ul, ol, figure, blockquote, dl, dd { margin: 0; }

ul, ol { padding: 0; list-style: none; }

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

button, input, select, textarea {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
}

button { cursor: pointer; }

table { border-collapse: collapse; width: 100%; }

[hidden] { display: none !important; }

::selection { background: rgba(123, 92, 255, .45); color: #FFFFFF; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  /* 色板 */
  --ink:        #04070F;
  --ink-2:      #0B122B;
  --panel:      #121A38;
  --violet:     #7B5CFF;
  --violet-2:   #B7A6FF;
  --cyan:       #37E3D8;
  --silver:     #E4E8F5;
  --white:      #FFFFFF;
  --aurora:     #C9A0FF;
  --orbit:      #6E7893;
  --amber:      #FFB25C;

  /* 描边与玻璃 */
  --line:       rgba(123, 92, 255, .26);
  --line-soft:  rgba(228, 232, 245, .10);
  --glass:      rgba(18, 26, 56, .74);

  /* 光效与阴影 */
  --glow-cyan:    0 0 0 1px rgba(55, 227, 216, .50), 0 0 22px rgba(55, 227, 216, .30);
  --glow-violet:  0 12px 34px rgba(123, 92, 255, .34);
  --shadow-panel: 0 26px 70px rgba(0, 0, 0, .58);

  /* 圆角 */
  --r-xl:   32px;
  --r-lg:   26px;
  --r-md:   20px;
  --r-sm:   14px;
  --r-pill: 999px;

  /* 字号阶梯（1.25 倍） */
  --fs-xs:   .78rem;
  --fs-sm:   .875rem;
  --fs-base: 1.0625rem;
  --fs-md:   1.25rem;
  --fs-lg:   1.5625rem;
  --fs-xl:   1.953rem;
  --fs-2xl:  2.441rem;
  --fs-display: clamp(2.5rem, 6.6vw, 5.25rem);

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

  /* 布局 */
  --shell:  1240px;
  --gutter: clamp(18px, 4vw, 56px);
  --t:      .24s cubic-bezier(.32, .72, .30, 1);
}

/* ---------- 3. 中文排版基线 ---------- */
body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.75;
  letter-spacing: .01em;
  color: var(--silver);
  background-color: var(--ink);
  background-image:
    radial-gradient(140% 90% at 78% -10%, rgba(123, 92, 255, .16), transparent 58%),
    radial-gradient(110% 70% at 4% 12%, rgba(55, 227, 216, .07), transparent 62%);
  background-repeat: no-repeat;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--white);
  text-wrap: balance;
}

h1 { font-size: var(--fs-display); font-weight: 900; text-shadow: 0 0 40px rgba(55, 227, 216, .22); }
h2 { font-size: clamp(1.7rem, 3.6vw, 2.6rem); }
h3 { font-size: var(--fs-lg); line-height: 1.3; }
h4 { font-size: var(--fs-md); line-height: 1.36; }

p { line-height: 1.78; }

strong, b { color: var(--white); font-weight: 700; }

small { font-size: var(--fs-sm); }

a { color: var(--violet-2); text-decoration: none; transition: color var(--t); }
a:hover { color: var(--cyan); }

code, kbd, samp, .mono {
  font-family: var(--font-mono);
  font-size: .9em;
  background: var(--panel);
  color: var(--cyan);
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  padding: .14em .5em;
  word-break: break-word;
}

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

/* ---------- 4. 无障碍工具 ---------- */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 10px; left: 10px;
  z-index: 300;
  padding: 10px 20px;
  border-radius: var(--r-pill);
  background: var(--cyan);
  color: var(--ink);
  font-size: var(--fs-sm);
  font-weight: 700;
  transform: translateY(-220%);
  transition: transform .2s ease;
}
.skip-link:focus { transform: none; color: var(--ink); }

#main-content { display: block; scroll-margin-top: 96px; }

/* ---------- 5. 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border: 1px solid transparent;
  border-radius: var(--r-pill);
  font-size: var(--fs-sm);
  font-weight: 700;
  letter-spacing: .02em;
  line-height: 1.4;
  white-space: nowrap;
  text-decoration: none;
  transition: transform var(--t), box-shadow var(--t),
              background-color var(--t), color var(--t), border-color var(--t);
}
.btn:active { transform: scale(.98); }

.btn-primary {
  background-image: linear-gradient(120deg, var(--violet), #5B3FE0);
  color: var(--white);
  box-shadow: 0 10px 28px rgba(123, 92, 255, .34);
}
.btn-primary:hover {
  color: var(--white);
  box-shadow: 0 12px 36px rgba(123, 92, 255, .52), 0 0 0 1px rgba(55, 227, 216, .6);
}

.btn-ghost {
  background: rgba(123, 92, 255, .10);
  border-color: var(--line);
  color: var(--violet-2);
}
.btn-ghost:hover {
  color: var(--white);
  border-color: var(--cyan);
  box-shadow: var(--glow-cyan);
}

/* ---------- 6. 命令栏头部 ---------- */
.command-bar {
  position: sticky;
  top: 0;
  z-index: 120;
  background: rgba(4, 7, 15, .88);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
  transition: background-color var(--t), box-shadow var(--t);
}
.command-bar[data-scrolled] {
  background: rgba(4, 7, 15, .97);
  box-shadow: 0 16px 44px rgba(0, 0, 0, .55);
}

/* 星轨进度线 */
.command-bar::before {
  content: "";
  position: absolute;
  left: 0; bottom: -1px;
  width: 100%; height: 2px;
  transform: scaleX(var(--progress, 0));
  transform-origin: 0 50%;
  background-image: linear-gradient(90deg, var(--violet), var(--aurora) 55%, var(--cyan));
  z-index: 3;
}

.command-bar::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 1px;
  background-image: linear-gradient(90deg,
      transparent, rgba(123, 92, 255, .7) 22%,
      rgba(55, 227, 216, .7) 78%, transparent);
  opacity: .75;
  pointer-events: none;
}

.bar-inner {
  position: relative;
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 12px var(--gutter);
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(16px, 3vw, 40px);
  transition: padding var(--t);
}
.command-bar[data-scrolled] .bar-inner { padding-top: 7px; padding-bottom: 7px; }

/* 品牌标识 */
.brand {
  display: inline-flex;
  flex-direction: column;
  gap: 1px;
  text-decoration: none;
}
.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 1.05rem;
  font-weight: 900;
  letter-spacing: .16em;
  color: var(--white);
  line-height: 1.3;
}
.brand-mark::before {
  content: "";
  width: 10px; height: 10px;
  border-radius: 50%;
  background-image: radial-gradient(circle at 34% 34%, var(--cyan), var(--violet) 72%);
  box-shadow: 0 0 14px rgba(55, 227, 216, .85);
  flex: none;
}
.brand-line {
  font-size: .7rem;
  letter-spacing: .12em;
  color: var(--orbit);
  line-height: 1.5;
}
a.brand:hover .brand-mark { color: var(--cyan); }

/* 主导航 */
.site-nav { justify-self: center; }

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}
.nav-list a {
  position: relative;
  display: block;
  padding: 8px 15px;
  border-radius: var(--r-pill);
  font-size: .93rem;
  color: var(--silver);
  text-decoration: none;
  transition: color var(--t), background-color var(--t);
}
.nav-list a:hover { color: var(--white); background: rgba(123, 92, 255, .16); }
.nav-list a[aria-current="page"] { color: var(--white); font-weight: 700; }
.nav-list a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 15px; right: 15px; bottom: 1px;
  height: 2px;
  border-radius: 2px;
  background: var(--cyan);
  box-shadow: 0 0 10px rgba(55, 227, 216, .85);
}

.nav-extra { display: none; }

/* 工具区 */
.bar-tools {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
}

/* 检索 */
.search-field { position: relative; }

.search-field::before {
  content: "";
  position: absolute;
  left: 13px; top: 50%;
  width: 10px; height: 10px;
  margin-top: -7px;
  border: 1.5px solid var(--orbit);
  border-radius: 50%;
  pointer-events: none;
  transition: border-color var(--t);
}
.search-field::after {
  content: "";
  position: absolute;
  left: 21px; top: calc(50% + 2px);
  width: 7px; height: 1.5px;
  background: var(--orbit);
  border-radius: 2px;
  transform: rotate(45deg);
  pointer-events: none;
  transition: background-color var(--t);
}
.search-field:focus-within::before { border-color: var(--cyan); }
.search-field:focus-within::after { background: var(--cyan); }

.site-search {
  width: clamp(150px, 17vw, 236px);
  padding: 9px 14px 9px 34px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: var(--glass);
  color: var(--silver);
  font-size: var(--fs-sm);
  line-height: 1.5;
  transition: border-color var(--t), box-shadow var(--t), width var(--t);
}
.site-search::placeholder { color: var(--orbit); }
.site-search:hover { border-color: rgba(123, 92, 255, .5); }
.site-search:focus {
  outline: none;
  border-color: var(--cyan);
  box-shadow: var(--glow-cyan);
}
.site-search::-webkit-search-cancel-button { -webkit-appearance: none; }

.search-panel {
  position: absolute;
  top: calc(100% + 12px);
  right: -6px;
  width: min(380px, 84vw);
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--panel);
  box-shadow: var(--shadow-panel);
  z-index: 130;
}
.search-panel::before {
  content: "";
  position: absolute;
  top: -1px; left: 24px; right: 24px;
  height: 1px;
  background-image: linear-gradient(90deg, transparent, var(--cyan), transparent);
  opacity: .8;
}
.search-panel__hint {
  margin: 4px 8px 10px;
  font-size: var(--fs-xs);
  line-height: 1.7;
  color: var(--orbit);
}
.search-list { display: grid; gap: 2px; }

.search-item__link {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 10px 12px;
  border-radius: var(--r-sm);
  color: var(--silver);
  text-decoration: none;
  border: 1px solid transparent;
  transition: background-color var(--t), border-color var(--t), color var(--t);
}
.search-item__link:hover,
.search-item__link:focus-visible {
  background: rgba(123, 92, 255, .16);
  border-color: var(--line);
  color: var(--white);
}
.search-item__title { font-size: .92rem; font-weight: 600; }
.search-item__route {
  font-family: var(--font-mono);
  font-size: .72rem;
  color: var(--orbit);
  flex: none;
}

/* 服务时段状态点 */
.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 13px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-pill);
  background: rgba(18, 26, 56, .5);
  font-size: var(--fs-xs);
  color: var(--orbit);
  white-space: nowrap;
}
.status-pill::before {
  content: "";
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--orbit);
  flex: none;
  transition: background-color var(--t), box-shadow var(--t);
}
.status-pill.is-live { color: var(--cyan); border-color: rgba(55, 227, 216, .35); }
.status-pill.is-live::before { background: var(--cyan); box-shadow: 0 0 12px rgba(55, 227, 216, .95); }
.status-pill.is-idle { color: var(--amber); border-color: rgba(255, 178, 92, .3); }
.status-pill.is-idle::before { background: var(--amber); box-shadow: 0 0 12px rgba(255, 178, 92, .8); }

/* 移动导航按钮 */
.nav-toggle {
  position: relative;
  display: none;
  width: 42px; height: 42px;
  flex: none;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: var(--glass);
  transition: border-color var(--t), box-shadow var(--t);
}
.nav-toggle span {
  position: absolute;
  left: 11px;
  width: 20px; height: 1.6px;
  border-radius: 2px;
  background: var(--silver);
  transition: transform var(--t), opacity var(--t), background-color var(--t);
}
.nav-toggle span:nth-child(1) { top: 13px; }
.nav-toggle span:nth-child(2) { top: 20px; }
.nav-toggle span:nth-child(3) { top: 27px; }
.nav-toggle:hover { border-color: rgba(55, 227, 216, .55); }
.nav-toggle[aria-expanded="true"] {
  border-color: var(--cyan);
  box-shadow: var(--glow-cyan);
}
.nav-toggle[aria-expanded="true"] span { background: var(--cyan); }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 7. 深空页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(72px, 10vw, 140px);
  background-color: var(--ink-2);
  background-image:
    radial-gradient(120% 90% at 84% 0%, rgba(123, 92, 255, .22), transparent 58%),
    radial-gradient(90% 70% at 6% 100%, rgba(55, 227, 216, .10), transparent 62%);
  border-top: 1px solid var(--line);
  overflow: hidden;
}
.footer-aurora {
  position: absolute;
  top: -120px; left: -80px;
  width: 420px; height: 420px;
  border-radius: 50%;
  background-image: radial-gradient(circle, rgba(123, 92, 255, .30), transparent 68%);
  filter: blur(6px);
  pointer-events: none;
}

.footer-inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: clamp(56px, 8vw, 96px) var(--gutter) clamp(40px, 5vw, 64px);
  display: grid;
  grid-template-columns: minmax(210px, 1fr) minmax(0, 2fr) minmax(220px, 1fr);
  gap: clamp(32px, 4.5vw, 72px);
}

.footer-brand { display: flex; flex-direction: column; gap: 16px; }
.footer-brand .brand-mark { font-size: 1.15rem; }
.footer-note {
  max-width: 30ch;
  font-size: var(--fs-sm);
  line-height: 1.85;
  color: var(--orbit);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 40px);
}
.footer-col__title {
  margin-bottom: 16px;
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: .2em;
  color: var(--cyan);
  line-height: 1.6;
}
.footer-col ul { display: grid; gap: 10px; }
.footer-col a {
  font-size: var(--fs-sm);
  color: var(--silver);
  text-decoration: none;
  transition: color var(--t), padding-left var(--t);
}
.footer-col a:hover { color: var(--cyan); padding-left: 5px; }

.contact-list { display: grid; gap: 12px; }
.contact-row { display: grid; gap: 2px; }
.contact-key {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: .12em;
  color: var(--orbit);
}
.contact-val {
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--silver);
  word-break: break-word;
}

.footer-bottom {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--line-soft);
  background: rgba(4, 7, 15, .55);
}
.footer-bottom__inner {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 20px var(--gutter);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 28px;
  font-size: var(--fs-sm);
  color: var(--orbit);
}
.footer-copy { font-size: var(--fs-sm); color: var(--orbit); }
.footer-legal { display: flex; flex-wrap: wrap; gap: 18px; }
.footer-legal a { font-size: var(--fs-sm); color: var(--orbit); }
.footer-legal a:hover { color: var(--cyan); }
.footer-icp {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: .06em;
  color: var(--orbit);
}

/* ---------- 8. 版面骨架 ---------- */
.container {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding-inline: var(--gutter);
}
.section { padding-block: clamp(64px, 9vw, 112px); }

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 32px);
}
.span-narrow { grid-column: 1 / span 3; }
.span-wide   { grid-column: 4 / span 9; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: .22em;
  color: var(--cyan);
}
.eyebrow::before {
  content: "";
  width: 18px; height: 1px;
  background: var(--cyan);
  opacity: .7;
}

.lede {
  max-width: 52ch;
  font-size: var(--fs-md);
  line-height: 1.75;
  color: var(--silver);
}

.hairline {
  height: 1px;
  border: 0;
  background-image: linear-gradient(90deg,
      transparent, rgba(123, 92, 255, .55) 20%,
      rgba(55, 227, 216, .55) 80%, transparent);
}

/* 星座母题：星点层与光晕 */
.starfield { position: relative; }
.starfield::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    radial-gradient(1.6px 1.6px at 12% 22%, rgba(255, 255, 255, .55), transparent 62%),
    radial-gradient(1.2px 1.2px at 38% 74%, rgba(183, 166, 255, .52), transparent 62%),
    radial-gradient(1.5px 1.5px at 66% 18%, rgba(55, 227, 216, .48), transparent 62%),
    radial-gradient(1px 1px at 84% 58%, rgba(255, 255, 255, .42), transparent 62%),
    radial-gradient(1.3px 1.3px at 52% 42%, rgba(201, 160, 255, .42), transparent 62%),
    radial-gradient(1.1px 1.1px at 24% 88%, rgba(228, 232, 245, .38), transparent 62%);
}

.glow-orb {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  background-image: radial-gradient(circle, rgba(123, 92, 255, .34), transparent 68%);
  filter: blur(4px);
}

/* ---------- 9. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--line);
  border-radius: var(--r-xl);
  overflow: hidden;
  background-color: var(--ink-2);
  background-image:
    radial-gradient(120% 90% at 20% 8%, rgba(123, 92, 255, .34), transparent 60%),
    radial-gradient(90% 80% at 86% 92%, rgba(55, 227, 216, .18), transparent 64%);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    radial-gradient(1.5px 1.5px at 18% 28%, rgba(255, 255, 255, .6), transparent 62%),
    radial-gradient(1.2px 1.2px at 62% 16%, rgba(55, 227, 216, .5), transparent 62%),
    radial-gradient(1.3px 1.3px at 78% 66%, rgba(201, 160, 255, .5), transparent 62%),
    radial-gradient(1px 1px at 34% 82%, rgba(228, 232, 245, .45), transparent 62%);
}
.media-frame img,
.media-frame svg {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--tall   { aspect-ratio: 3 / 4; }
.media-frame--wide   { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }

/* ---------- 10. 分段切换 / 标签页 ---------- */
.segmented {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(18, 26, 56, .8);
}
.segmented [data-tab] {
  position: relative;
  padding: 9px 20px;
  border: 0;
  border-radius: var(--r-pill);
  background: transparent;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--orbit);
  transition: color var(--t), background-color var(--t);
}
.segmented [data-tab]:hover { color: var(--silver); }
.segmented [data-tab][aria-selected="true"] {
  color: var(--white);
  background: rgba(123, 92, 255, .22);
  box-shadow: inset 0 -2px 0 var(--cyan);
}

[data-tab-panel] { animation: panelIn .18s ease both; }
@keyframes panelIn { from { opacity: 0; } to { opacity: 1; } }

/* ---------- 11. 手风琴 ---------- */
.accordion-item { border-bottom: 1px solid var(--line-soft); }
.accordion-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  width: 100%;
  padding: 20px 16px 20px 0;
  text-align: left;
  font-size: var(--fs-md);
  font-weight: 700;
  color: var(--white);
  border-left: 2px solid transparent;
  transition: background-color var(--t), border-color var(--t), color var(--t);
}
.accordion-trigger::after {
  content: "";
  width: 9px; height: 9px;
  border-right: 1.6px solid var(--orbit);
  border-bottom: 1.6px solid var(--orbit);
  transform: rotate(45deg);
  transition: transform var(--t), border-color var(--t);
  flex: none;
}
.accordion-trigger:hover { color: var(--cyan); }
.accordion-trigger[aria-expanded="true"] {
  color: var(--cyan);
  border-left-color: var(--cyan);
  background: var(--panel);
  padding-left: 16px;
}
.accordion-trigger[aria-expanded="true"]::after {
  transform: rotate(225deg);
  border-color: var(--cyan);
}
.accordion-panel {
  padding: 0 16px 24px;
  background: var(--panel);
  border-left: 2px solid var(--cyan);
  color: var(--silver);
}

/* ---------- 12. 面包屑 ---------- */
.breadcrumb { padding-block: 18px; font-size: var(--fs-xs); }
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  color: var(--orbit);
}
.breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: rgba(110, 120, 147, .6);
}
.breadcrumb a { color: var(--orbit); }
.breadcrumb a:hover { color: var(--cyan); }
.breadcrumb [aria-current="page"] { color: var(--violet-2); }

/* ---------- 13. 显现与回到顶部 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .24s ease, transform .24s ease;
}
.reveal.is-in { opacity: 1; transform: none; }

.back-to-top {
  position: fixed;
  right: clamp(16px, 3vw, 34px);
  bottom: clamp(16px, 3vw, 34px);
  z-index: 110;
  display: grid;
  place-items: center;
  width: 48px; height: 48px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity var(--t), transform var(--t),
              visibility var(--t), border-color var(--t), box-shadow var(--t);
}
.back-to-top::before {
  content: "";
  width: 10px; height: 10px;
  margin-top: 4px;
  border-left: 1.6px solid var(--cyan);
  border-top: 1.6px solid var(--cyan);
  transform: rotate(45deg);
}
.back-to-top.is-visible { opacity: 1; visibility: visible; transform: none; }
.back-to-top:hover { border-color: var(--cyan); box-shadow: var(--glow-cyan); }

/* ---------- 14. 响应式 ---------- */

/* 平板横屏与窄桌面：命令栏收为抽屉 */
@media (max-width: 1100px) {
  .bar-inner {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 14px;
  }
  .nav-toggle { display: block; }
  .status-pill { display: none; }

  .site-nav {
    position: absolute;
    left: 0; right: 0; top: 100%;
    display: none;
    padding: 14px var(--gutter) 24px;
    background-image: linear-gradient(180deg, rgba(11, 18, 43, .99), rgba(4, 7, 15, .99));
    border-bottom: 1px solid var(--line);
    box-shadow: 0 34px 70px rgba(0, 0, 0, .62);
    max-height: calc(100vh - 64px);
    overflow-y: auto;
  }
  .site-nav[data-open] { display: block; }

  .nav-list { flex-direction: column; align-items: stretch; gap: 2px; }
  .nav-list a {
    padding: 13px 16px;
    border-radius: var(--r-sm);
    font-size: 1rem;
  }
  .nav-list a[aria-current="page"]::after {
    left: 0; right: auto;
    top: 13px; bottom: 13px;
    width: 3px; height: auto;
    border-radius: 3px;
  }
  .nav-extra { display: block; margin-top: 14px; }
  .nav-extra .btn { width: 100%; }

  .footer-inner { grid-template-columns: minmax(0, 1fr); }
  .footer-nav { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

/* 平板竖屏 */
@media (max-width: 900px) {
  :root { --fs-base: 1rem; }
  .site-search { width: clamp(140px, 26vw, 200px); }
  .grid-12 { grid-template-columns: minmax(0, 1fr); }
  .span-narrow, .span-wide { grid-column: 1 / -1; }
  .footer-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 26px; }
  .footer-bottom__inner { justify-content: flex-start; }
}

/* 手机 */
@media (max-width: 700px) {
  :root { --gutter: 16px; }
  .cta-new { display: none; }
  .brand-line { display: none; }
  .brand-mark { font-size: .98rem; letter-spacing: .12em; }
  .site-search { width: clamp(112px, 38vw, 168px); font-size: var(--fs-xs); }
  .search-panel { right: -8px; }
  .footer-nav { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .footer-col {
    padding-block: 18px;
    border-bottom: 1px solid var(--line-soft);
  }
  .footer-col:last-child { border-bottom: 0; }
  .footer-col__title { margin-bottom: 12px; }
  .footer-bottom__inner { flex-direction: column; align-items: flex-start; gap: 8px; }
  .footer-legal { gap: 14px; }
}

/* ---------- 15. 动效降级 ---------- */
@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;
  }
  .reveal { opacity: 1; transform: none; }
}