/* ============================================================
   /assets/site.css — 博九娱乐 共享样式
   ============================================================ */

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body, h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd, hr { 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; }
a { color: inherit; }
hr { border: 0; }

/* ---------- tokens ---------- */
:root {
  --c-ink: #0E1B2C;
  --c-deep: #14263D;
  --c-indigo: #1E3A5F;
  --c-amber: #D9A441;
  --c-amber-lt: #F0C674;
  --c-rock: #6B7785;
  --c-porcelain: #F6F3EC;
  --c-paper: #EDE6D8;
  --c-teal: #3E7F72;
  --c-ochre: #A8552F;
  --c-hair: #C9C2B4;
  --line: rgba(201, 194, 180, 0.22);
  --line-strong: rgba(201, 194, 180, 0.42);
  --line-faint: rgba(201, 194, 180, 0.08);
  --shadow-card: 0 1px 2px rgba(4, 10, 18, 0.35);

  --font-display: "Songti SC", "Source Han Serif SC", "Noto Serif SC", "Songti TC", Georgia, "Times New Roman", serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --fs-12: 0.75rem;
  --fs-14: 0.875rem;
  --fs-16: 1rem;
  --fs-18: 1.125rem;
  --fs-22: 1.375rem;
  --fs-28: 1.75rem;
  --fs-36: 2.25rem;
  --fs-48: 3rem;

  --container: 1280px;
  --gutter: clamp(20px, 4vw, 56px);
  --header-h: 96px;
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
}

@media (max-width: 1024px) {
  :root { --header-h: 84px; }
}

/* ---------- base typography ---------- */
body {
  font-family: var(--font-body);
  font-size: var(--fs-16);
  line-height: 1.75;
  letter-spacing: 0.01em;
  color: var(--c-porcelain);
  background-color: var(--c-ink);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.01em;
  text-wrap: balance;
}

h1 { font-size: clamp(2.25rem, 5vw, 4rem); }
h2 { font-size: clamp(1.75rem, 3vw, 2.25rem); }
h3 { font-size: var(--fs-22); }

p { max-width: 68ch; }

a { text-decoration-thickness: 1px; text-underline-offset: 4px; }

#main-content { scroll-margin-top: calc(var(--header-h) + 16px); }

html.nav-open, html.nav-open body { overflow: hidden; }

/* ---------- focus ---------- */
:where(a, button, input, select, textarea, summary, [tabindex]):focus-visible {
  outline: 2px solid var(--c-amber);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- utilities ---------- */
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
}

.muted { color: var(--c-rock); }

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(48px, 7vw, 96px); }

.section--panel { background-color: var(--c-indigo); }

.section--paper {
  background-color: var(--c-porcelain);
  color: var(--c-deep);
  --line: rgba(20, 38, 61, 0.14);
  --line-strong: rgba(20, 38, 61, 0.30);
  --line-faint: rgba(20, 38, 61, 0.06);
  --c-rock: #59646F;
}

.section--paper .btn--ghost {
  color: var(--c-deep);
  border-color: var(--line-strong);
}

.section--paper .btn--ghost:hover {
  color: var(--c-deep);
  border-color: var(--c-amber);
  background-color: rgba(217, 164, 65, 0.14);
}

.rule {
  height: 1px;
  width: 100%;
  background-color: var(--line);
  border: 0;
}

.plate {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-amber);
}

.plate::before {
  content: "";
  width: 18px;
  height: 1px;
  background-color: currentColor;
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.08em;
  color: var(--c-teal);
}

.status::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: currentColor;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 22px;
  font-family: var(--font-body);
  font-size: var(--fs-14);
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.02em;
  border: 1px solid transparent;
  border-radius: 2px;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease),
              border-color 0.2s var(--ease), transform 0.2s var(--ease);
}

.btn--primary {
  background-color: var(--c-amber);
  color: #151006;
  box-shadow: var(--shadow-card);
}

.btn--primary:hover {
  background-color: var(--c-amber-lt);
  transform: translateY(-1px);
}

.btn--ghost {
  background-color: transparent;
  color: var(--c-porcelain);
  border-color: var(--line-strong);
}

.btn--ghost:hover {
  color: var(--c-amber-lt);
  border-color: var(--c-amber);
}

.text-btn {
  appearance: none;
  background: none;
  border: 0;
  padding: 4px 2px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  color: var(--c-rock);
  cursor: pointer;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.text-btn:hover {
  color: var(--c-amber-lt);
  border-bottom-color: var(--c-amber);
}

.copy-btn {
  align-self: start;
  appearance: none;
  background-color: transparent;
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: 8px 10px;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.12em;
  color: var(--c-rock);
  cursor: pointer;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.copy-btn:hover {
  color: var(--c-amber-lt);
  border-color: var(--c-amber);
}

.copy-btn[data-copied="true"] {
  color: var(--c-teal);
  border-color: var(--c-teal);
}

/* ---------- skip link ---------- */
.skip-link {
  position: absolute;
  top: -120px;
  left: var(--gutter);
  z-index: 120;
  padding: 12px 18px;
  background-color: var(--c-amber);
  color: #151006;
  font-size: var(--fs-14);
  font-weight: 700;
  text-decoration: none;
  border-radius: 2px;
  transition: top 0.18s var(--ease);
}

.skip-link:focus {
  top: 10px;
}

/* ============================================================
   HEADER
   ============================================================ */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 80;
  color: var(--c-porcelain);
  background-color: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color 0.24s var(--ease), border-color 0.24s var(--ease),
              box-shadow 0.24s var(--ease);
}

.site-header[data-scrolled="true"] {
  background-color: var(--c-deep);
  border-bottom-color: var(--line);
  box-shadow: 0 1px 2px rgba(4, 10, 18, 0.4);
}

/* 顶部坐标轨 */
.header-rail {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 8px var(--gutter);
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-rock);
  background-color: rgba(14, 27, 44, 0.55);
  border-bottom: 1px solid var(--line-faint);
  transition: color 0.24s var(--ease), background-color 0.24s var(--ease);
}

.site-header[data-scrolled="true"] .header-rail {
  color: var(--c-amber);
  background-color: transparent;
}

.header-rail__mark,
.header-rail__meta {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-rail__meta { color: inherit; opacity: 0.72; }

/* 主行 */
.header-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: clamp(16px, 2.4vw, 40px);
  max-width: var(--container);
  margin-inline: auto;
  padding: 14px var(--gutter);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}

.brand__glyph {
  position: relative;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 800;
  line-height: 1;
  color: var(--c-amber);
  border: 1px solid var(--c-amber);
  clip-path: polygon(0 0, calc(100% - 9px) 0, 100% 9px, 100% 100%, 0 100%);
  background-color: rgba(217, 164, 65, 0.08);
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.brand__name {
  font-family: var(--font-display);
  font-size: var(--fs-18);
  font-weight: 800;
  letter-spacing: 0.03em;
  line-height: 1.1;
}

.brand__tagline {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.1em;
  color: var(--c-rock);
  line-height: 1.3;
}

/* 移动端按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  background-color: transparent;
  color: inherit;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.14em;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.nav-toggle:hover { border-color: var(--c-amber); color: var(--c-amber-lt); }

.nav-toggle__bar {
  position: relative;
  display: block;
  width: 20px;
  height: 1.5px;
  background-color: currentColor;
  transition: background-color 0.2s var(--ease);
}

.nav-toggle__bar::before,
.nav-toggle__bar::after {
  content: "";
  position: absolute;
  left: 0;
  width: 20px;
  height: 1.5px;
  background-color: currentColor;
  transition: transform 0.22s var(--ease);
}

.nav-toggle__bar::before { top: -6px; }
.nav-toggle__bar::after { top: 6px; }

.site-header[data-open="true"] .nav-toggle__bar { background-color: transparent; }
.site-header[data-open="true"] .nav-toggle__bar::before { transform: translateY(6px) rotate(45deg); }
.site-header[data-open="true"] .nav-toggle__bar::after { transform: translateY(-6px) rotate(-45deg); }

/* 导航 */
.site-nav {
  display: flex;
  justify-content: center;
}

.site-nav__title { display: none; }

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 26px);
}

.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 6px 2px 8px;
  font-size: 0.9375rem;
  letter-spacing: 0.02em;
  text-decoration: none;
  color: var(--c-porcelain);
  white-space: nowrap;
  transition: color 0.2s var(--ease);
}

.site-nav__num {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.06em;
  color: var(--c-rock);
  transition: color 0.2s var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 1px;
  background-color: var(--c-amber);
  transition: width 0.2s var(--ease);
}

.site-nav__link:hover,
.site-nav__link:focus-visible { color: var(--c-amber-lt); }
.site-nav__link:hover::after,
.site-nav__link:focus-visible::after { width: 100%; }

.site-nav__link[aria-current="page"] { color: var(--c-amber-lt); }
.site-nav__link[aria-current="page"]::after { width: 100%; background-color: var(--c-amber); }
.site-nav__link[aria-current="page"] .site-nav__num { color: var(--c-amber); }

.site-nav__foot { display: none; }

/* 右侧动作 */
.header-actions {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.2vw, 20px);
}

.search-link {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  text-decoration: none;
  color: var(--c-rock);
  padding-bottom: 3px;
  border-bottom: 1px solid var(--line-strong);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.search-link:hover {
  color: var(--c-amber-lt);
  border-bottom-color: var(--c-amber);
}

/* ============================================================
   移动端抽屉导航
   ============================================================ */
@media (max-width: 1024px) {
  .header-inner {
    grid-template-columns: 1fr auto;
    gap: 12px;
  }

  .nav-toggle { display: inline-flex; }
  .header-actions { display: none; }

  .site-header::before {
    content: "";
    position: fixed;
    inset: 0;
    background-color: rgba(6, 12, 20, 0.66);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s var(--ease), visibility 0.2s var(--ease);
  }

  .site-header[data-open="true"]::before {
    opacity: 1;
    visibility: visible;
  }

  .site-nav {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 2;
    width: min(88vw, 380px);
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    gap: 0;
    padding: 28px clamp(20px, 5vw, 32px) 32px;
    background-color: var(--c-deep);
    border-right: 1px solid var(--line-strong);
    overflow-y: auto;
    transform: translateX(-102%);
    visibility: hidden;
    transition: transform 0.24s var(--ease), visibility 0.24s var(--ease);
  }

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

  .site-nav__title {
    display: block;
    margin-bottom: 18px;
    font-family: var(--font-mono);
    font-size: 0.625rem;
    letter-spacing: 0.18em;
    color: var(--c-amber);
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
  }

  .site-nav__item { border-bottom: 1px solid var(--line); }

  .site-nav__link {
    display: flex;
    align-items: baseline;
    gap: 14px;
    padding: 16px 2px;
    font-size: var(--fs-16);
  }

  .site-nav__link::after { display: none; }

  .site-nav__link[aria-current="page"] {
    border-left: 1px solid var(--c-amber);
    padding-left: 12px;
    margin-left: -13px;
  }

  .site-nav__foot {
    display: block;
    margin-top: auto;
    padding-top: 28px;
  }

  .site-nav__foot-note {
    margin-bottom: 14px;
    font-family: var(--font-mono);
    font-size: 0.625rem;
    line-height: 1.8;
    letter-spacing: 0.08em;
    color: var(--c-rock);
    max-width: none;
  }

  .site-nav__foot .btn { width: 100%; }
}

@media (max-width: 760px) {
  .brand__tagline { display: none; }
  .header-rail__meta { display: none; }
}

/* ============================================================
   BREADCRUMB
   ============================================================ */
.breadcrumb-bar {
  padding-top: var(--header-h);
  background-color: var(--c-deep);
  border-bottom: 1px solid var(--line);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  max-width: var(--container);
  margin-inline: auto;
  padding: 12px var(--gutter);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  color: var(--c-rock);
}

.breadcrumb__link {
  color: var(--c-rock);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.breadcrumb__link:hover {
  color: var(--c-amber-lt);
  border-bottom-color: var(--c-amber);
}

.breadcrumb__sep {
  color: var(--c-hair);
  opacity: 0.5;
}

.breadcrumb__current { color: var(--c-porcelain); }

.breadcrumb__back {
  margin-left: auto;
  color: var(--c-amber);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 2px;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.breadcrumb__back:hover {
  color: var(--c-amber-lt);
  border-bottom-color: var(--c-amber-lt);
}

/* ============================================================
   GRID / CARD / FIGURE / PROSE
   ============================================================ */
.grid {
  display: grid;
  gap: clamp(16px, 2.2vw, 32px);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--auto { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

@media (max-width: 860px) {
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }
}

.card {
  position: relative;
  padding: clamp(18px, 2vw, 28px);
  background-color: rgba(30, 58, 95, 0.38);
  border: 1px solid var(--line);
  border-radius: 2px;
  box-shadow: var(--shadow-card);
  transition: border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.card::after {
  content: "";
  position: absolute;
  top: 8px;
  right: 8px;
  width: 14px;
  height: 14px;
  border-top: 1px solid var(--c-rock);
  border-right: 1px solid var(--c-rock);
  opacity: 0.7;
  transition: border-color 0.2s var(--ease), opacity 0.2s var(--ease);
  pointer-events: none;
}

.card:hover {
  border-color: var(--line-strong);
  background-color: rgba(30, 58, 95, 0.55);
}

.card:hover::after {
  border-color: var(--c-amber);
  opacity: 1;
}

.section--paper .card {
  background-color: var(--c-paper);
  border-color: var(--line);
  box-shadow: 0 1px 2px rgba(20, 38, 61, 0.1);
}

.section--paper .card:hover { background-color: #f2ecdf; }

/* 图片容器 */
.figure { margin: 0; }

.figure__media {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background-color: var(--c-indigo);
  border: 1px solid var(--line);
  border-radius: 2px;
}

.figure__media > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure--wide .figure__media { aspect-ratio: 21 / 9; }
.figure--tall .figure__media { aspect-ratio: 3 / 4; }

.figure__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  color: var(--c-rock);
  max-width: 60ch;
}

/* 长文档 */
.prose { max-width: 68ch; }
.prose > * + * { margin-top: 1.2em; }

.prose h2 {
  font-size: clamp(1.5rem, 2.4vw, 2rem);
  margin-top: 1.9em;
  margin-bottom: 0.6em;
}

.prose h3 {
  margin-top: 1.6em;
  margin-bottom: 0.5em;
}

.prose p { margin: 0; max-width: none; }

.prose a {
  color: var(--c-amber);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
  transition: border-color 0.2s var(--ease);
}

.prose a:hover { border-bottom-color: var(--c-amber); }

.prose ul li,
.prose ol li {
  position: relative;
  padding-left: 24px;
  margin-top: 0.55em;
}

.prose ul li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--c-amber);
}

.prose ol { counter-reset: prose-ol; }

.prose ol li::before {
  counter-increment: prose-ol;
  content: counter(prose-ol, decimal-leading-zero);
  position: absolute;
  left: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  color: var(--c-amber);
  top: 0.25em;
}

/* ============================================================
   TABS（页面阶段可选组件）
   ============================================================ */
.tabs { display: block; }

.tabs__list {
  display: flex;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--line);
  margin-bottom: clamp(16px, 2vw, 28px);
}

.tabs__tab {
  appearance: none;
  background: none;
  border: 0;
  border-bottom: 2px solid transparent;
  padding: 12px 18px;
  margin-bottom: -1px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  color: var(--c-rock);
  cursor: pointer;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.tabs__tab:hover { color: var(--c-porcelain); }

.tabs__tab[aria-selected="true"] {
  color: var(--c-amber-lt);
  border-bottom-color: var(--c-amber);
}

.tabs__panel:focus-visible { outline: 2px solid var(--c-amber); outline-offset: 6px; }
.tabs__panel[hidden] { display: none; }

/* ============================================================
   进度条 / 显现
   ============================================================ */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 95;
  width: 100%;
  height: 2px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background-color: var(--c-amber);
  pointer-events: none;
}

html.js [data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.42s var(--ease), transform 0.42s var(--ease);
  transition-delay: var(--reveal-delay, 0ms);
}

html.js [data-reveal="shown"] {
  opacity: 1;
  transform: none;
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  position: relative;
  color: var(--c-porcelain);
  background-color: var(--c-deep);
  border-top: 1px solid var(--line-strong);
  background-image:
    linear-gradient(var(--line-faint) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-faint) 1px, transparent 1px);
  background-size: 96px 96px;
  background-position: 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.15fr 1.3fr 0.85fr 1fr;
  gap: clamp(24px, 3vw, 48px);
  max-width: var(--container);
  margin-inline: auto;
  padding: clamp(48px, 6vw, 88px) var(--gutter) clamp(32px, 4vw, 48px);
}

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

.footer-heading {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-amber);
}

.footer-heading::after {
  content: "";
  flex: 1;
  height: 1px;
  background-color: var(--line);
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: inherit;
  margin-bottom: 16px;
}

.footer-brand__glyph {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 800;
  line-height: 1;
  color: var(--c-amber);
  border: 1px solid var(--c-amber);
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 0 100%);
}

.footer-brand__name {
  font-family: var(--font-display);
  font-size: var(--fs-18);
  font-weight: 800;
  letter-spacing: 0.04em;
}

.footer-note {
  font-size: var(--fs-14);
  line-height: 1.75;
  color: var(--c-rock);
  max-width: 34ch;
}

.footer-note--tight {
  margin-top: 14px;
  font-size: 0.8125rem;
  max-width: none;
}

.footer-inline-link {
  color: var(--c-amber);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
  transition: border-color 0.2s var(--ease);
}

.footer-inline-link:hover { border-bottom-color: var(--c-amber); }

.footer-icp {
  margin-top: 18px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  color: var(--c-rock);
}

.footer-copy {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
  color: var(--c-rock);
}

/* 反馈卡 */
.feedback-card {
  display: block;
  padding: 20px 22px;
  text-decoration: none;
  color: inherit;
  background-color: rgba(30, 58, 95, 0.6);
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 0 100%);
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease),
              transform 0.2s var(--ease);
}

.feedback-card:hover,
.feedback-card:focus-visible {
  background-color: rgba(30, 58, 95, 0.95);
  border-color: var(--c-amber);
  transform: translateY(-2px);
}

.feedback-card__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.16em;
  color: var(--c-amber);
  margin-bottom: 8px;
}

.feedback-card__title {
  display: block;
  font-family: var(--font-display);
  font-size: var(--fs-18);
  font-weight: 700;
  letter-spacing: 0.01em;
  line-height: 1.4;
  margin-bottom: 8px;
}

.feedback-card__desc {
  display: block;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--c-rock);
  margin-bottom: 14px;
}

.feedback-card__more {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--c-amber-lt);
}

/* 目录 */
.footer-list__item { border-bottom: 1px solid var(--line-faint); }

.footer-list__item:first-child { border-top: 1px solid var(--line-faint); }

.footer-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 0;
  font-size: var(--fs-14);
  text-decoration: none;
  color: var(--c-porcelain);
  transition: color 0.2s var(--ease), padding-left 0.2s var(--ease);
}

.footer-link:hover {
  color: var(--c-amber-lt);
  padding-left: 6px;
}

/* 联系 */
.contact-list { display: block; }

.contact-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 4px 12px;
  padding-block: 12px;
  border-bottom: 1px solid var(--line-faint);
}

.contact-item:first-child { padding-top: 0; }
.contact-item:last-child { border-bottom: 0; }

.contact-item__label {
  grid-column: 1 / -1;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.16em;
  color: var(--c-rock);
}

.contact-item__value {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--c-porcelain);
  overflow-wrap: anywhere;
}

/* 页脚底部 */
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  max-width: var(--container);
  margin-inline: auto;
  padding: 18px var(--gutter) 28px;
  border-top: 1px solid var(--line);
}

.footer-meta {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  color: var(--c-rock);
  max-width: none;
}

.footer-bottom__actions {
  display: flex;
  align-items: center;
  gap: 20px;
}

@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 680px) {
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

/* ============================================================
   动效降级
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  html.js [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }

  .feedback-card:hover,
  .btn--primary:hover {
    transform: none;
  }

  .footer-link:hover { padding-left: 0; }
}