/* ==========================================================================
   EMC体育官方 · /assets/site.css
   共享外壳：reset / 变量 / 中文排版 / 刊头 / 页脚 / 通用组件
   ========================================================================== */

/* --- 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, li, figure, figcaption, 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; }

button { background: none; border: 0; padding: 0; cursor: pointer; }

a { color: inherit; text-decoration: none; }

hr { border: 0; }

:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 3px;
  border-radius: 6px;
}

/* --- 2. 设计变量 --------------------------------------------------------- */
:root {
  --pitch-950: #05100D;
  --pitch-900: #0A1B17;
  --pitch-800: #10261F;
  --pitch-700: #17352C;
  --moss-600: #1F4A3D;
  --cyan-400: #34E2D0;
  --cyan-200: #9FF2E7;
  --ember-500: #FF5A2B;
  --ember-300: #FF9C74;
  --paper-050: #E9F4F0;
  --ink-1000: #02100C;
  --ash-400: #7E9C93;

  --line: rgba(23, 53, 44, 0.95);
  --line-soft: rgba(31, 74, 61, 0.6);
  --text: rgba(233, 244, 240, 0.86);
  --text-dim: #7E9C93;

  --font-display: "Source Han Sans SC", "Noto Sans SC", "PingFang SC",
    "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-body: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei",
    "Noto Sans SC", "Hiragino Sans GB", sans-serif;
  --font-mono: ui-monospace, "JetBrains Mono", "IBM Plex Mono", "SFMono-Regular",
    Menlo, Consolas, "Courier New", monospace;

  --shell: 1180px;
  --gutter: clamp(1rem, 4vw, 2.5rem);

  --r-lg: 24px;
  --r-md: 16px;
  --r-sm: 12px;
  --r-pill: 999px;

  --dur: 180ms;
  --dur-slow: 220ms;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* --- 3. 基础排版 --------------------------------------------------------- */
body {
  min-height: 100vh;
  background-color: var(--pitch-950);
  background-image:
    linear-gradient(to right, rgba(23, 53, 44, 0.32) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(23, 53, 44, 0.32) 1px, transparent 1px);
  background-size: 72px 72px, 72px 72px;
  color: var(--text);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  overflow-x: hidden;
}

.display-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-stretch: condensed;
  font-size: clamp(2rem, 5vw, 4rem);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--paper-050);
}

.lede {
  font-size: 1.125rem;
  line-height: 1.75;
  max-width: 34em;
  color: rgba(233, 244, 240, 0.78);
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.08em;
  font-variant-numeric: tabular-nums;
}

.coord {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.16em;
  color: rgba(126, 156, 147, 0.72);
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan-400);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--cyan-400), rgba(52, 226, 208, 0.15));
}

.prose {
  max-width: 34em;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: rgba(233, 244, 240, 0.82);
}

.prose > * + * { margin-top: 1.2em; }

.prose h2 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.375rem;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--paper-050);
  margin-top: 1.8em;
}

.prose h3 {
  font-size: 1.125rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--paper-050);
  margin-top: 1.5em;
}

.prose strong { color: var(--cyan-200); font-weight: 700; }

.prose a {
  color: var(--cyan-200);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(52, 226, 208, 0.45);
  transition: color var(--dur) var(--ease);
}

.prose a:hover { color: var(--cyan-400); text-decoration-color: var(--cyan-400); }

.prose li { position: relative; padding-left: 1.15rem; }
.prose li + li { margin-top: 0.5em; }

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan-400);
  opacity: 0.78;
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  letter-spacing: 0.04em;
  color: var(--cyan-200);
  background: rgba(23, 53, 44, 0.75);
  padding: 0.1em 0.42em;
  border-radius: 6px;
}

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

/* --- 4. 布局原语 --------------------------------------------------------- */
.container {
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--narrow { max-width: 52rem; }

.section {
  position: relative;
  padding: clamp(2.5rem, 7vw, 5rem) 0;
}

.section--alt { background: var(--pitch-900); }

.section--paper {
  background: var(--paper-050);
  color: var(--ink-1000);
}

.section--paper .display-title,
.section--paper h2,
.section--paper h3 { color: var(--ink-1000); }

.section--paper .lede,
.section--paper .prose { color: rgba(2, 16, 12, 0.78); }

.section--paper .eyebrow { color: #0A1B17; }
.section--paper .eyebrow::before { background: linear-gradient(90deg, #0A1B17, rgba(10, 27, 23, 0.12)); }

.section--paper .prose strong { color: #0A1B17; }

.section--paper .prose a {
  color: #0A1B17;
  text-decoration-color: rgba(10, 27, 23, 0.35);
}

.section--paper .prose li::before { background: var(--ember-500); }

.section--paper .coord,
.section--paper .mono { color: rgba(2, 16, 12, 0.6); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem 2rem;
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.grid {
  display: grid;
  gap: clamp(1rem, 3vw, 1.75rem);
}

.grid--2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

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

.stack > * + * { margin-top: var(--stack-gap, 1rem); }

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

.rule--accent {
  height: 2px;
  background: linear-gradient(90deg, var(--cyan-400), rgba(255, 90, 43, 0.7) 55%, transparent);
}

/* 蓝图网格底：坐标与细线，作为装饰层 */
.blueprint {
  position: relative;
  background-image:
    linear-gradient(to right, rgba(23, 53, 44, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(23, 53, 44, 0.55) 1px, transparent 1px);
  background-size: 48px 48px, 48px 48px;
}

/* 斜切色块容器：12°，窄屏降为 6° */
.slice {
  position: relative;
  overflow: hidden;
}

.slice--a { clip-path: polygon(0 12%, 100% 0, 100% 100%, 0 100%); }
.slice--b { clip-path: polygon(0 0, 100% 0, 100% 88%, 0 100%); }

/* --- 5. 通用组件 --------------------------------------------------------- */
.actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.78rem 1.4rem;
  border: 1px solid transparent;
  border-radius: var(--r-pill);
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background-color var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              color var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease);
}

.btn--primary {
  background: var(--cyan-400);
  color: var(--pitch-950);
  box-shadow: 0 14px 32px -22px rgba(52, 226, 208, 0.9);
}

.btn--primary:hover {
  background: var(--cyan-200);
  box-shadow: 0 18px 40px -20px rgba(52, 226, 208, 0.95);
}

.btn--ghost {
  border-color: rgba(52, 226, 208, 0.45);
  color: var(--cyan-200);
  background: rgba(52, 226, 208, 0.05);
}

.btn--ghost:hover {
  border-color: var(--cyan-400);
  background: rgba(52, 226, 208, 0.13);
  color: var(--cyan-200);
}

.btn--ember {
  background: var(--ember-500);
  color: var(--ink-1000);
}

.btn--ember:hover { background: var(--ember-300); }

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

.section--paper .btn--ghost {
  border-color: rgba(10, 27, 23, 0.35);
  color: #0A1B17;
  background: rgba(10, 27, 23, 0.04);
}

.section--paper .btn--ghost:hover {
  border-color: #0A1B17;
  background: rgba(10, 27, 23, 0.1);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.32rem 0.72rem;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(16, 38, 31, 0.7);
  color: var(--ash-400);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0.08em;
}

.chip--cyan {
  color: var(--cyan-200);
  border-color: rgba(52, 226, 208, 0.5);
  background: rgba(52, 226, 208, 0.1);
}

.chip--ember {
  color: var(--ember-300);
  border-color: rgba(255, 90, 43, 0.5);
  background: rgba(255, 90, 43, 0.12);
}

.card {
  position: relative;
  padding: 1.25rem 1.35rem 1.35rem;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--pitch-800);
  transition: transform var(--dur-slow) var(--ease),
              background-color var(--dur-slow) var(--ease),
              border-color var(--dur-slow) var(--ease),
              box-shadow var(--dur-slow) var(--ease);
}

.card:hover {
  transform: translateY(-2px);
  background: var(--pitch-700);
  border-color: rgba(52, 226, 208, 0.6);
  box-shadow: 0 26px 60px -34px rgba(0, 0, 0, 0.95);
}

.card--float { box-shadow: 0 30px 70px -40px rgba(0, 0, 0, 0.95); }

.card__index {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--cyan-400);
}

.card__title {
  margin: 0.55rem 0 0.4rem;
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 800;
  line-height: 1.4;
  color: var(--paper-050);
}

.card__meta {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--ash-400);
}

.section--paper .card {
  background: rgba(255, 255, 255, 0.6);
  border-color: rgba(10, 27, 23, 0.14);
  color: var(--ink-1000);
}

.section--paper .card:hover {
  background: rgba(255, 255, 255, 0.9);
  border-color: rgba(10, 27, 23, 0.35);
}

.section--paper .card__title { color: var(--ink-1000); }
.section--paper .card__index { color: #0A1B17; }
.section--paper .card__meta { color: rgba(2, 16, 12, 0.6); }

.stat {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.stat__value {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--cyan-200);
}

.stat__label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1.5;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ash-400);
}

.stat--ember .stat__value { color: var(--ember-500); }

.media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background:
    linear-gradient(140deg, rgba(16, 38, 31, 0.95), rgba(31, 74, 61, 0.85));
  aspect-ratio: 16 / 9;
  width: 100%;
}

.media-frame img,
.media-frame svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 1.5rem 1.15rem 1rem;
  background: linear-gradient(to top, rgba(2, 16, 12, 0.88), transparent);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--cyan-200);
}

.media-frame__index {
  position: absolute;
  top: 0.85rem;
  left: 0.85rem;
  padding: 0.28rem 0.62rem;
  border-radius: var(--r-pill);
  background: rgba(5, 16, 13, 0.78);
  border: 1px solid rgba(52, 226, 208, 0.45);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--cyan-200);
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  letter-spacing: 0.06em;
  color: var(--ash-400);
}

.breadcrumbs__item { display: inline-flex; align-items: center; gap: 0.5rem; }
.breadcrumbs__item + .breadcrumbs__item::before { content: "/"; color: var(--line); }
.breadcrumbs a { color: var(--cyan-200); transition: color var(--dur) var(--ease); }
.breadcrumbs a:hover { color: var(--cyan-400); }

.accordion {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: rgba(16, 38, 31, 0.55);
  overflow: hidden;
}

.accordion + .accordion { margin-top: 0.6rem; }

.accordion__summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.15rem;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--paper-050);
  cursor: pointer;
  list-style: none;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.accordion__summary::-webkit-details-marker { display: none; }
.accordion__summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.125rem;
  line-height: 1;
  color: var(--cyan-400);
}

.accordion[open] .accordion__summary { background: rgba(23, 53, 44, 0.6); }
.accordion[open] .accordion__summary::after { content: "–"; }
.accordion__summary:hover { color: var(--cyan-200); background: rgba(23, 53, 44, 0.55); }

.accordion__body {
  padding: 0 1.15rem 1.15rem;
  font-size: 1rem;
  line-height: 1.75;
  color: rgba(233, 244, 240, 0.8);
}

.timeline {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 0.4rem;
  bottom: 0.4rem;
  left: 5px;
  width: 1px;
  background: var(--line);
}

.timeline__item {
  position: relative;
  padding: 0 0 1.5rem 1.75rem;
}

.timeline__item:last-child { padding-bottom: 0; }

.timeline__marker {
  position: absolute;
  left: 0;
  top: 0.4rem;
  width: 11px;
  height: 11px;
  border: 2px solid var(--cyan-400);
  border-radius: 50%;
  background: var(--pitch-950);
}

.timeline__body { font-size: 1rem; line-height: 1.75; }

.timeline__label {
  display: block;
  margin-bottom: 0.25rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--ash-400);
}

.pulse {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan-400);
  animation: emc-pulse 2.4s var(--ease) infinite;
}

@keyframes emc-pulse {
  0%   { box-shadow: 0 0 0 0 rgba(52, 226, 208, 0.55); opacity: 1; }
  70%  { box-shadow: 0 0 0 9px rgba(52, 226, 208, 0);    opacity: 0.55; }
  100% { box-shadow: 0 0 0 0 rgba(52, 226, 208, 0);      opacity: 1; }
}

/* 滚动显现（由共享脚本加 .is-visible；无 JS 时不隐藏内容） */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

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

/* --- 6. 刊头 ------------------------------------------------------------- */
.skip-link {
  position: absolute;
  left: 1rem;
  top: -120%;
  z-index: 100;
  padding: 0.68rem 1.15rem;
  border-radius: var(--r-pill);
  background: var(--cyan-400);
  color: var(--pitch-950);
  font-size: 0.875rem;
  font-weight: 700;
  line-height: 1.2;
  transition: top var(--dur) var(--ease);
}

.skip-link:focus { top: 0.75rem; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(5, 16, 13, 0.94);
  border-bottom: 1px solid var(--line);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.site-header[data-condensed="true"] { background: rgba(5, 16, 13, 0.985); }

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan-400), var(--ember-500));
  transition: width 90ms linear;
}

.header-inner {
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.masthead {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 1rem;
  padding: 1rem 0 0.7rem;
  transition: padding var(--dur-slow) var(--ease);
}

.masthead__brand {
  grid-column: 2;
  display: flex;
  align-items: center;
  gap: 0.65rem;
  transition: color var(--dur) var(--ease);
}

.masthead__brand:hover { color: var(--cyan-200); }

.brand-mark {
  position: relative;
  flex: 0 0 auto;
  width: 30px;
  height: 30px;
  border: 1px solid rgba(52, 226, 208, 0.45);
  border-radius: 10px;
  background: linear-gradient(150deg, var(--moss-600), var(--pitch-800));
  box-shadow: inset 0 0 0 1px rgba(5, 16, 13, 0.65);
}

.brand-mark::before {
  content: "";
  position: absolute;
  inset: 7px;
  border: 2px solid var(--cyan-400);
  border-right-color: transparent;
  border-bottom-color: transparent;
  border-radius: 50%;
  transform: rotate(-45deg);
}

.brand-mark::after {
  content: "";
  position: absolute;
  right: 4px;
  bottom: 4px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--ember-500);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: 0.01em;
  color: var(--paper-050);
  transition: font-size var(--dur-slow) var(--ease);
}

.brand-note {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0.2em;
  color: var(--cyan-400);
}

.masthead__utility {
  grid-column: 3;
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.utility-link {
  display: inline-flex;
  align-items: center;
  padding: 0.44rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(10, 27, 23, 0.6);
  color: rgba(233, 244, 240, 0.8);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0.06em;
  white-space: nowrap;
  transition: color var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              background-color var(--dur) var(--ease);
}

.utility-link:hover {
  border-color: rgba(52, 226, 208, 0.6);
  background: rgba(31, 74, 61, 0.55);
  color: var(--cyan-200);
}

.utility-link--accent {
  border-color: rgba(255, 90, 43, 0.45);
  color: var(--ember-300);
}

.utility-link--accent:hover {
  border-color: var(--ember-500);
  background: rgba(255, 90, 43, 0.14);
  color: var(--ember-300);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(10, 27, 23, 0.6);
  color: var(--cyan-200);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.1em;
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.nav-toggle:hover,
.nav-toggle[aria-expanded="true"] {
  border-color: rgba(52, 226, 208, 0.6);
  background: rgba(31, 74, 61, 0.55);
}

.nav-toggle__bars {
  display: block;
  width: 16px;
  height: 12px;
  background-image:
    linear-gradient(currentColor, currentColor),
    linear-gradient(currentColor, currentColor),
    linear-gradient(currentColor, currentColor);
  background-repeat: no-repeat;
  background-size: 16px 2px, 16px 2px, 16px 2px;
  background-position: 0 0, 0 5px, 0 10px;
}

.primary-nav { position: relative; }

.nav-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 0.25rem;
  padding: 0.1rem 0 0.55rem;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 0.9rem;
  border-radius: var(--r-pill);
  color: rgba(233, 244, 240, 0.72);
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1.3;
  white-space: nowrap;
  transition: color var(--dur) var(--ease),
              background-color var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease);
}

.nav-link:hover {
  color: var(--cyan-200);
  background: rgba(31, 74, 61, 0.5);
}

.nav-link[aria-current="page"] {
  color: var(--paper-050);
  background: rgba(31, 74, 61, 0.7);
  box-shadow: inset 0 0 0 1px rgba(52, 226, 208, 0.55);
}

.site-header[data-condensed="true"] .masthead { padding: 0.5rem 0 0.4rem; }
.site-header[data-condensed="true"] .brand-note { display: none; }
.site-header[data-condensed="true"] .brand-name { font-size: 1.0625rem; }
.site-header[data-condensed="true"] .nav-list { padding-bottom: 0.4rem; }

@media (min-width: 901px) {
  .primary-nav { border-top: 1px solid rgba(23, 53, 44, 0.8); }
}

/* --- 7. 页脚 ------------------------------------------------------------- */
.site-footer {
  position: relative;
  margin-top: clamp(2rem, 6vw, 4rem);
  border-top: 1px solid var(--line);
  background-color: var(--pitch-950);
  background-image:
    linear-gradient(to right, rgba(23, 53, 44, 0.35) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(23, 53, 44, 0.35) 1px, transparent 1px),
    linear-gradient(180deg, var(--pitch-900), var(--pitch-950) 62%);
  background-size: 64px 64px, 64px 64px, auto;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: min(46%, 520px);
  height: 3px;
  background: linear-gradient(90deg, var(--cyan-400), var(--ember-500) 72%, transparent);
}

.footer-inner {
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(2.5rem, 6vw, 4.25rem) var(--gutter) 1.75rem;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) minmax(0, 2fr);
  gap: clamp(1.75rem, 4vw, 3.5rem);
}

.footer-brand__marker {
  display: block;
  width: 44px;
  height: 4px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--cyan-400), var(--ember-500));
  margin-bottom: 0.9rem;
}

.footer-brand__name {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: 0.01em;
  color: var(--paper-050);
}

.footer-brand__note {
  margin-top: 0.3rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  line-height: 1.6;
  letter-spacing: 0.2em;
  color: var(--cyan-400);
}

.footer-brand__line {
  margin-top: 0.9rem;
  max-width: 32ch;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--ash-400);
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
}

.footer-col__title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ash-400);
}

.footer-list {
  display: grid;
  gap: 0.55rem;
  margin-top: 0.9rem;
}

.footer-link {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: rgba(233, 244, 240, 0.78);
  transition: color var(--dur) var(--ease);
}

.footer-link:hover {
  color: var(--cyan-200);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(52, 226, 208, 0.5);
}

.footer-contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.6rem 1.5rem;
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
  padding-top: 1.35rem;
  border-top: 1px solid var(--line);
}

.footer-contact__item {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: rgba(233, 244, 240, 0.82);
}

.footer-contact__label {
  color: var(--ash-400);
  letter-spacing: 0.14em;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
  margin-top: 1.5rem;
  padding-top: 1.35rem;
  border-top: 1px solid var(--line);
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--ash-400);
}

.footer-legal {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--cyan-200);
}

.footer-note { max-width: 48ch; }

.footer-copy {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
}

/* --- 8. 响应式 ----------------------------------------------------------- */
@media (max-width: 1024px) {
  .grid--sidebar { grid-template-columns: minmax(0, 1fr); }
}

@media (min-width: 1024px) {
  .card--shift { margin-inline-start: -1.5rem; }
}

@media (max-width: 900px) {
  .masthead {
    grid-template-columns: auto 1fr auto;
    gap: 0.5rem;
    padding: 0.75rem 0 0.6rem;
  }

  .masthead__brand { grid-column: 1; justify-self: start; }

  .masthead__utility {
    grid-column: 1 / -1;
    grid-row: 2;
    justify-self: center;
    padding-top: 0.15rem;
  }

  .nav-toggle { display: inline-flex; grid-column: 3; justify-self: end; }

  .primary-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    z-index: 5;
    padding-inline: var(--gutter);
    background: var(--pitch-900);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 34px 60px -34px rgba(0, 0, 0, 0.95);
  }

  html.js .primary-nav {
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    transition: max-height 260ms var(--ease), visibility 0s linear 260ms;
  }

  html.js .primary-nav[data-open="true"] {
    max-height: min(72vh, 520px);
    overflow: auto;
    visibility: visible;
    transition: max-height 260ms var(--ease), visibility 0s;
  }

  .nav-list {
    flex-direction: column;
    flex-wrap: nowrap;
    align-items: stretch;
    gap: 2px;
    padding: 0.6rem 0 0.9rem;
  }

  .nav-link {
    width: 100%;
    justify-content: flex-start;
    padding: 0.72rem 0.9rem;
    border-radius: 14px;
    font-size: 1rem;
  }

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

@media (max-width: 640px) {
  body { font-size: 16px; }
  .slice--a { clip-path: polygon(0 6%, 100% 0, 100% 100%, 0 100%); }
  .slice--b { clip-path: polygon(0 0, 100% 0, 100% 94%, 0 100%); }
  .footer-cols { grid-template-columns: minmax(0, 1fr); gap: 1.25rem; }
  .masthead__utility { gap: 0.4rem; }
  .utility-link { padding: 0.38rem 0.7rem; font-size: 0.75rem; }
  .brand-name { font-size: 1.125rem; }
  .display-title { font-size: clamp(1.75rem, 8vw, 2.5rem); }
}

/* --- 9. 降低动效 --------------------------------------------------------- */
@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;
    transition-delay: 0s !important;
  }

  .card:hover { transform: none; }
  html.js [data-reveal] { opacity: 1; transform: none; }
  .pulse { animation: none; box-shadow: none; }
}