/* ============================================================
   K8 中文站 · /assets/site.css
   共享外壳：头部、页脚、排版、按钮、网格与基础组件
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 20px);
}

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

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

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

a { color: var(--cyan); text-decoration: none; }

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

[hidden] { display: none !important; }

/* ---------- 2. Tokens ---------- */
:root {
  /* 色彩 */
  --navy-900: #071A2F;
  --navy-800: #0B2742;
  --navy-700: #102F4A;
  --line: #3A6B8A;
  --line-soft: rgba(58, 107, 138, 0.45);
  --orange: #FF7A1A;
  --orange-soft: #FFB070;
  --cyan: #2DE2E6;
  --cyan-soft: #7CF0F2;
  --paper: #F4F8FF;
  --mist: #9DB4CC;
  --green: #38E8A0;
  --yellow: #FFC857;
  --ink: #0A1522;

  /* 字体 */
  --font-display: "Barlow Condensed", "Oswald", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-editorial: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;

  /* 度量 */
  --maxw: 1240px;
  --gutter: clamp(18px, 4vw, 48px);
  --header-h: 76px;
  --gap: clamp(16px, 2.2vw, 28px);
}

/* ---------- 3. 基础排版与背景 ---------- */
body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.8;
  color: var(--paper);
  background-color: var(--navy-900);
  background-image:
    linear-gradient(to right, rgba(58, 107, 138, 0.14) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(58, 107, 138, 0.14) 1px, transparent 1px),
    radial-gradient(1100px 640px at 84% -8%, rgba(45, 226, 230, 0.16), transparent 62%),
    radial-gradient(820px 520px at 2% 2%, rgba(255, 122, 26, 0.12), transparent 58%),
    linear-gradient(180deg, #071A2F 0%, #071A2F 38%, #0B2742 100%);
  background-size: 72px 72px, 72px 72px, auto, auto, auto;
  background-repeat: repeat, repeat, no-repeat, no-repeat, no-repeat;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection {
  background: rgba(45, 226, 230, 0.3);
  color: #ffffff;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: 0.005em;
  color: var(--paper);
  text-wrap: balance;
}

h1 { font-size: clamp(32px, 4.6vw, 58px); }
h2 { font-size: clamp(24px, 3vw, 40px); }
h3 { font-size: clamp(19px, 2vw, 24px); }
h4 { font-size: 18px; }

p { line-height: 1.85; }

strong { color: var(--paper); font-weight: 600; }

/* 焦点可见 */
:where(a, button, input, select, textarea, summary, [tabindex]):focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 1px;
}

/* ---------- 4. 工具类 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.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;
}

.mono { font-family: var(--font-mono); letter-spacing: 0.02em; }

.skip-link {
  position: fixed;
  top: -80px;
  left: var(--gutter);
  z-index: 200;
  padding: 12px 22px;
  background: var(--cyan);
  color: #04212E;
  font-weight: 700;
  font-size: 14px;
  border: 1px solid #0B3A47;
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 12px;
}

/* ---------- 5. 布局 ---------- */
.section {
  position: relative;
  padding-block: clamp(52px, 7.5vw, 104px);
}

.section--band {
  background:
    linear-gradient(90deg, rgba(11, 39, 66, 0.94), rgba(7, 26, 47, 0.35) 78%),
    radial-gradient(720px 320px at 90% 0%, rgba(45, 226, 230, 0.1), transparent 70%);
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.grid {
  display: grid;
  gap: var(--gap);
}
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr); }
.grid--sidebar { grid-template-columns: minmax(220px, 280px) minmax(0, 1fr); }

/* ---------- 6. 章节语言 ---------- */
.eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan);
}
.eyebrow::before {
  content: "";
  flex: none;
  width: 28px;
  height: 1px;
  background: currentColor;
  opacity: 0.85;
}

.display {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(38px, 6.4vw, 74px);
  line-height: 0.98;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.chapter-no {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(44px, 6vw, 84px);
  line-height: 0.85;
  letter-spacing: 0.02em;
  color: transparent;
  -webkit-text-stroke: 1.2px rgba(45, 226, 230, 0.55);
}
@supports not (-webkit-text-stroke: 1px #000) {
  .chapter-no { color: rgba(45, 226, 230, 0.55); }
}

.lede {
  font-family: var(--font-editorial);
  font-size: clamp(16px, 1.35vw, 19px);
  line-height: 1.95;
  color: #C4D6E8;
}

.prose {
  max-width: 72ch;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(244, 248, 255, 0.84);
}
.prose p { margin: 0 0 1.15em; }
.prose h2 { margin: 2em 0 0.7em; font-size: clamp(22px, 2.4vw, 30px); }
.prose h3 { margin: 1.8em 0 0.6em; }
.prose ul { margin: 0 0 1.15em; padding-left: 1.3em; list-style: disc; }
.prose ol { margin: 0 0 1.15em; padding-left: 1.4em; list-style: decimal; }
.prose li { margin: 0.4em 0; }
.prose a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}
.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  padding: 2px 6px;
  background: rgba(45, 226, 230, 0.1);
  border: 1px solid rgba(45, 226, 230, 0.25);
  color: var(--cyan-soft);
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 26px;
  border: 1px solid transparent;
  border-radius: 0;
  background: transparent;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.05em;
  line-height: 1.2;
  text-align: center;
  cursor: pointer;
  transition:
    background 0.25s ease,
    border-color 0.25s ease,
    color 0.25s ease,
    box-shadow 0.3s ease,
    transform 0.2s ease;
}

.btn--primary {
  background: linear-gradient(135deg, #FF8A2B, #FF6A00 72%);
  color: #0A1522;
  border-color: rgba(255, 182, 120, 0.6);
  box-shadow:
    0 0 0 1px rgba(255, 122, 26, 0.35),
    0 10px 26px -14px rgba(255, 122, 26, 0.95);
}
.btn--primary:hover {
  box-shadow:
    0 0 0 1px rgba(255, 122, 26, 0.9),
    0 12px 32px -10px rgba(255, 122, 26, 0.8);
  transform: translateY(-1px);
}

.btn--ghost {
  border-color: rgba(45, 226, 230, 0.45);
  background: rgba(45, 226, 230, 0.06);
  color: var(--cyan);
}
.btn--ghost:hover {
  border-color: var(--cyan);
  background: rgba(45, 226, 230, 0.14);
  box-shadow: 0 0 24px -10px rgba(45, 226, 230, 0.95);
}

.btn--sm {
  padding: 9px 16px;
  font-size: 13px;
  letter-spacing: 0.04em;
}

.btn--block { width: 100%; }

/* ---------- 8. 标签 / 卡片 / 面板 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.5;
  letter-spacing: 0.08em;
  color: var(--mist);
  background: rgba(16, 47, 74, 0.6);
  border: 1px solid rgba(58, 107, 138, 0.7);
}
.tag--live {
  color: var(--green);
  border-color: rgba(56, 232, 160, 0.45);
  background: rgba(56, 232, 160, 0.08);
}
.tag--warn {
  color: var(--yellow);
  border-color: rgba(255, 200, 87, 0.45);
  background: rgba(255, 200, 87, 0.08);
}
.tag--accent {
  color: var(--orange-soft);
  border-color: rgba(255, 122, 26, 0.5);
  background: rgba(255, 122, 26, 0.08);
}

.card {
  position: relative;
  padding: clamp(18px, 2.2vw, 30px);
  background: linear-gradient(160deg, rgba(16, 47, 74, 0.95), rgba(9, 31, 52, 0.92));
  border: 1px solid rgba(58, 107, 138, 0.55);
  transition: border-color 0.3s ease, box-shadow 0.3s ease, transform 0.3s ease;
}
.card:hover {
  border-color: rgba(45, 226, 230, 0.55);
  box-shadow:
    0 0 0 1px rgba(45, 226, 230, 0.16),
    0 22px 48px -30px rgba(45, 226, 230, 0.85);
  transform: translateY(-2px);
}
.card__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 21px;
  line-height: 1.25;
  color: var(--paper);
}

.panel {
  position: relative;
  padding: clamp(16px, 2vw, 24px);
  background: rgba(11, 39, 66, 0.72);
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--orange);
}

/* ---------- 9. 主题筛选 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 clamp(20px, 3vw, 32px);
  padding: 0;
  list-style: none;
}
.filter-btn {
  padding: 9px 16px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--mist);
  background: rgba(16, 47, 74, 0.55);
  border: 1px solid rgba(58, 107, 138, 0.7);
  cursor: pointer;
  transition: color 0.22s ease, border-color 0.22s ease, background 0.22s ease, box-shadow 0.25s ease;
}
.filter-btn:hover {
  color: var(--paper);
  border-color: rgba(45, 226, 230, 0.7);
}
.filter-btn[aria-pressed="true"] {
  color: #FFC79B;
  border-color: var(--orange);
  background: rgba(255, 122, 26, 0.14);
  box-shadow: 0 0 22px -12px rgba(255, 122, 26, 1);
}
.filter-item {
  animation: filter-in 0.32s ease both;
}
@keyframes filter-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 10. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}
.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: rgba(157, 180, 204, 0.5);
}
.breadcrumb a {
  color: var(--mist);
  text-decoration: none;
  transition: color 0.2s ease;
}
.breadcrumb a:hover { color: var(--cyan); }
.breadcrumb [aria-current="page"] { color: var(--paper); }

/* ---------- 11. 图片容器基础（页面阶段放入占位或图片） ---------- */
.figure { margin: 0; }

.figure__media {
  position: relative;
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  border: 1px solid rgba(58, 107, 138, 0.5);
  background-color: #0A2338;
  background-image:
    radial-gradient(60% 80% at 82% 8%, rgba(45, 226, 230, 0.16), transparent 70%),
    radial-gradient(52% 70% at 8% 92%, rgba(255, 122, 26, 0.14), transparent 70%),
    linear-gradient(to right, rgba(58, 107, 138, 0.22) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(58, 107, 138, 0.22) 1px, transparent 1px);
  background-size: auto, auto, 36px 36px, 36px 36px;
}
.figure__media img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.figure__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(157, 180, 204, 0.72);
}
.figure__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.03em;
  color: var(--mist);
}
.figure--wide .figure__media { aspect-ratio: 2 / 1; }
.figure--square .figure__media { aspect-ratio: 1 / 1; }
.figure--tall .figure__media { aspect-ratio: 3 / 4; }

/* ---------- 12. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: linear-gradient(180deg, rgba(7, 26, 47, 0.9), rgba(7, 26, 47, 0.28));
  border-bottom: 1px solid rgba(58, 107, 138, 0.28);
  transition: background 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}
.site-header.is-solid {
  background: rgba(7, 24, 43, 0.97);
  border-bottom-color: rgba(58, 107, 138, 0.62);
  box-shadow: 0 16px 44px -28px rgba(0, 0, 0, 0.95);
}

.header-inner {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(14px, 2vw, 34px);
  width: 100%;
  max-width: var(--maxw);
  min-height: var(--header-h);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: none;
  color: inherit;
  text-decoration: none;
}
.brand__mark {
  position: relative;
  display: grid;
  place-items: center;
  flex: none;
  width: 42px;
  height: 42px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: 0.04em;
  color: var(--cyan);
  border: 1px solid rgba(45, 226, 230, 0.6);
  background: linear-gradient(150deg, rgba(45, 226, 230, 0.18), rgba(255, 122, 26, 0.12));
}
.brand__mark::after {
  content: "";
  position: absolute;
  right: -1px;
  bottom: -1px;
  width: 9px;
  height: 9px;
  background: var(--orange);
}
.brand__text { display: block; }
.brand__name {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  line-height: 1.1;
  letter-spacing: 0.06em;
  color: var(--paper);
}
.brand__tag {
  display: block;
  margin-top: 3px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  line-height: 1.4;
  letter-spacing: 0.16em;
  color: var(--mist);
}

.header-nav { justify-self: end; }

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.nav-link {
  position: relative;
  display: block;
  padding: 10px 13px;
  font-size: 15px;
  line-height: 1.2;
  color: rgba(244, 248, 255, 0.8);
  text-decoration: none;
  transition: color 0.2s ease, background 0.2s ease;
}
.nav-link:hover {
  color: var(--paper);
  background: rgba(45, 226, 230, 0.08);
}
.nav-link[aria-current="page"] { color: var(--paper); }
.nav-link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 13px;
  right: 13px;
  bottom: 2px;
  height: 2px;
  background: linear-gradient(90deg, var(--orange), var(--orange-soft));
}
.nav-meta { display: none; }

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: none;
}
.header-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.5;
  letter-spacing: 0.06em;
  color: var(--mist);
  white-space: nowrap;
}

.status-dot {
  position: relative;
  display: inline-block;
  flex: none;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 10px rgba(56, 232, 160, 0.9);
}
.status-dot::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1px solid var(--green);
  animation: status-pulse 2.8s ease-out infinite;
}
.status-dot--sm { width: 6px; height: 6px; }

@keyframes status-pulse {
  0% { transform: scale(1); opacity: 0.8; }
  70% { transform: scale(3.2); opacity: 0; }
  100% { transform: scale(3.2); opacity: 0; }
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  color: var(--paper);
  background: rgba(16, 47, 74, 0.7);
  border: 1px solid rgba(58, 107, 138, 0.7);
  cursor: pointer;
  transition: border-color 0.2s ease, background 0.2s ease;
}
.nav-toggle:hover {
  border-color: var(--cyan);
  background: rgba(45, 226, 230, 0.1);
}
.nav-toggle__box {
  display: grid;
  gap: 5px;
  width: 20px;
}
.nav-toggle__bar {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform 0.25s ease, opacity 0.2s ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.header-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan), var(--cyan-soft) 42%, var(--orange));
  pointer-events: none;
}

/* ---------- 13. 页脚 ---------- */
.site-footer {
  position: relative;
  color: var(--paper);
  background: linear-gradient(180deg, rgba(11, 39, 66, 0.96), #061528 72%, #050F1C);
  border-top: 1px solid rgba(58, 107, 138, 0.55);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), rgba(45, 226, 230, 0.12) 34%, rgba(255, 122, 26, 0.12) 66%, var(--orange));
}

.footer-inner {
  max-width: var(--maxw);
  margin-inline: auto;
  padding: clamp(40px, 6vw, 76px) var(--gutter) 0;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr) minmax(0, 1fr) minmax(0, 1.2fr);
  gap: clamp(26px, 3.4vw, 52px);
}

.footer-brand__name {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 22px;
  letter-spacing: 0.08em;
  color: var(--paper);
}
.footer-brand__tag {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}
.footer-summary {
  max-width: 34ch;
  margin: 0 0 18px;
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(157, 180, 204, 0.95);
}
.footer-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 6px 12px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--mist);
  border: 1px solid rgba(58, 107, 138, 0.5);
}

.footer-col__title {
  margin: 0 0 18px;
  padding-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--paper);
  border-bottom: 1px solid rgba(58, 107, 138, 0.4);
}

.footer-list {
  display: grid;
  gap: 11px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.footer-link {
  display: inline-block;
  font-size: 14.5px;
  line-height: 1.6;
  color: rgba(196, 214, 232, 0.86);
  text-decoration: none;
  transition: color 0.2s ease, transform 0.2s ease;
}
.footer-link:hover {
  color: var(--cyan);
  transform: translateX(2px);
}

.footer-list--contact { gap: 16px; }
.footer-contact__item {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 10px;
  font-size: 13.5px;
  line-height: 1.65;
  color: rgba(196, 214, 232, 0.9);
}
.footer-contact__label {
  display: block;
  width: 100%;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  color: rgba(157, 180, 204, 0.75);
}
.footer-contact__value { word-break: break-all; }

.copy-btn {
  margin-left: 2px;
  padding: 3px 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mist);
  background: transparent;
  border: 1px solid rgba(58, 107, 138, 0.8);
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.copy-btn:hover {
  color: var(--cyan);
  border-color: var(--cyan);
}
.copy-btn[data-copied="true"] {
  color: var(--green);
  border-color: rgba(56, 232, 160, 0.75);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 28px;
  margin-top: clamp(32px, 5vw, 56px);
  padding-block: 20px 30px;
  border-top: 1px solid rgba(58, 107, 138, 0.4);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(157, 180, 204, 0.85);
}
.footer-copy { margin: 0; }
.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.footer-legal .footer-link { font-size: 12px; }

/* ---------- 14. 滚动显现 ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.2, 0.7, 0.2, 1);
  will-change: opacity, transform;
}
.js [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 15. 响应式 ---------- */
@media (max-width: 1199px) {
  .header-status { display: none; }
}

@media (max-width: 1023px) {
  .header-inner { grid-template-columns: minmax(0, 1fr) auto; }
  .nav-toggle { display: inline-flex; }

  .header-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    justify-self: stretch;
    padding: 10px var(--gutter) 26px;
    background: linear-gradient(180deg, #0A2137, #06182A);
    border-bottom: 1px solid rgba(58, 107, 138, 0.6);
    box-shadow: 0 30px 60px -30px rgba(0, 0, 0, 0.95);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity 0.26s ease, transform 0.26s ease, visibility 0.26s ease;
  }
  .header-nav[data-open="true"] {
    visibility: visible;
    opacity: 1;
    transform: none;
  }
  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .nav-link {
    padding: 15px 4px;
    font-size: 17px;
    border-bottom: 1px solid rgba(58, 107, 138, 0.32);
  }
  .nav-link[aria-current="page"]::after {
    left: 4px;
    right: auto;
    bottom: 9px;
    width: 28px;
  }
  .nav-meta {
    display: block;
    margin: 16px 0 0;
    font-family: var(--font-mono);
    font-size: 11.5px;
    letter-spacing: 0.1em;
    color: rgba(157, 180, 204, 0.8);
  }

  .grid--3,
  .grid--4,
  .grid--sidebar { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--split { grid-template-columns: minmax(0, 1fr); }

  .footer-top { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 719px) {
  .footer-top { grid-template-columns: minmax(0, 1fr); gap: 32px; }
}

@media (max-width: 680px) {
  .grid--2,
  .grid--3,
  .grid--4,
  .grid--sidebar,
  .grid--split { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 620px) {
  .header-cta { display: none; }
  .btn { padding: 12px 20px; font-size: 14.5px; }
}

@media (max-width: 540px) {
  .brand__tag { display: none; }
  .brand__mark { width: 38px; height: 38px; font-size: 16px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

/* ---------- 16. 无障碍：减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .status-dot::after { display: none; }
  .js [data-reveal] { opacity: 1; transform: none; }
  .filter-item { animation: none; }
  .card:hover,
  .btn--primary:hover,
  .footer-link:hover { transform: none; }
}