/* ==========================================================================
   米兰看台 /assets/site.css
   共享外壳：变量、重置、排版、头部、导航、页脚、通用组件
   ========================================================================== */

:root {
  /* 色彩体系：近单色 + 单一亮色 + 三枚状态灯 */
  --ink: #0B0C0E;
  --stand: #16181C;
  --concrete: #2A2D33;
  --mist: #8A8F98;
  --bone: #F2F0EC;
  --red: #D5122B;
  --red-bright: #FF4A5E;
  --red-deep: #7A0E1E;
  --mint: #23E0A8;
  --amber: #F5A524;
  --steel: #C9CBD1;

  /* 字体栈 */
  --font-display: 'Archivo Narrow', 'Oswald', 'Noto Sans SC', sans-serif;
  --font-serif: 'Source Serif SC', 'Noto Serif SC', serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', monospace;

  /* 尺度 */
  --max: 1280px;
  --gutter: 48px;
  --header-h: 72px;
  --radius: 2px;

  /* 间距节奏：4px 基线 */
  --s1: 4px;
  --s2: 8px;
  --s3: 12px;
  --s4: 16px;
  --s5: 24px;
  --s6: 32px;
  --s7: 48px;
  --s8: 80px;
}

/* ---------- 重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  background: var(--ink);
}

body {
  margin: 0;
  background: var(--ink);
  color: var(--bone);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.78;
  font-weight: 400;
  letter-spacing: 0.005em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

ul, ol { margin: 0; padding: 0; }

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
}

a { color: var(--bone); text-decoration-color: var(--concrete); }

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

hr { border: 0; border-top: 1px solid var(--concrete); margin: var(--s6) 0; }

::selection {
  background: var(--red);
  color: #fff;
}

/* ---------- 焦点可见 ---------- */
:focus-visible {
  outline: 2px solid var(--mint);
  outline-offset: 3px;
  border-radius: var(--radius);
}

:focus:not(:focus-visible) { outline: none; }

#main-content:focus { outline: none; }

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

.mono {
  font-family: var(--font-mono);
  font-size: 0.9375em;
  letter-spacing: 0.08em;
  font-variant-numeric: tabular-nums;
}

.skip-link {
  position: absolute;
  left: var(--s4);
  top: -120px;
  z-index: 300;
  display: inline-block;
  padding: var(--s3) var(--s5);
  background: var(--red);
  color: #fff;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-decoration: none;
  border-radius: var(--radius);
  transition: top 0.2s ease;
}

.skip-link:focus { top: var(--s3); }

/* ---------- 布局容器 ---------- */
.container {
  width: 100%;
  max-width: calc(var(--max) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--narrow { max-width: calc(880px + var(--gutter) * 2); }

/* ---------- 状态灯 ---------- */
.status-dot {
  display: inline-block;
  flex: none;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--concrete);
  vertical-align: middle;
  transition: background-color 0.28s ease, box-shadow 0.28s ease;
}

.status-dot--live {
  background: var(--mint);
  animation: status-pulse 2.6s ease-in-out infinite;
}

.status-dot--warn { background: var(--amber); }

.status-dot--alert { background: var(--red-bright); }

@keyframes status-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(35, 224, 168, 0.45); }
  50%      { box-shadow: 0 0 0 5px rgba(35, 224, 168, 0); }
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s2);
  padding: 13px 20px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  line-height: 1;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.15s ease;
}

.btn--primary {
  background: var(--red);
  border-color: var(--red);
  color: #fff;
}

.btn--primary:hover {
  background: var(--red-deep);
  border-color: var(--red-bright);
  color: #fff;
}

.btn--primary:active { transform: translateY(1px); }

.btn--ghost {
  background: transparent;
  border-color: var(--concrete);
  color: var(--bone);
}

.btn--ghost:hover {
  border-color: var(--steel);
  color: #fff;
}

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

/* ---------- 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11, 12, 14, 0.94);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--concrete);
}

.site-header__progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: transparent;
  overflow: hidden;
  pointer-events: none;
}

.site-header__progress-bar {
  display: block;
  width: 0;
  height: 100%;
  background: var(--red-bright);
  transition: width 0.1s linear;
}

.site-header__inner {
  width: 100%;
  max-width: calc(var(--max) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s5);
}

/* 品牌 */
.brand {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  text-decoration: none;
  color: var(--bone);
  flex: none;
}

.brand__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--bone);
  transition: color 0.2s ease;
}

.brand:hover .brand__name { color: #fff; }

.brand__meta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.brand__version { color: var(--steel); }

.brand__dot { color: var(--concrete); }

.brand__state { color: var(--mist); }

/* 移动端开关 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--s2);
  padding: 10px 12px;
  background: transparent;
  border: 1px solid var(--concrete);
  border-radius: var(--radius);
  color: var(--bone);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 12px;
  line-height: 1;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.nav-toggle:hover { border-color: var(--steel); }

.nav-toggle__icon {
  display: grid;
  gap: 4px;
  width: 16px;
}

.nav-toggle__icon i {
  display: block;
  height: 1.5px;
  width: 100%;
  background: currentColor;
  transition: transform 0.22s ease, opacity 0.22s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__icon i:nth-child(1) {
  transform: translateY(5.5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__icon i:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__icon i:nth-child(3) {
  transform: translateY(-5.5px) rotate(-45deg);
}

/* 主导航 */
.site-nav {
  display: flex;
  align-items: center;
  gap: var(--s6);
  margin-left: auto;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 26px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav__item { margin: 0; }

.site-nav__list a {
  position: relative;
  display: inline-block;
  padding: 6px 0;
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.4;
  letter-spacing: 0.04em;
  color: var(--mist);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s ease;
}

.site-nav__list a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--red-bright);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.22s ease;
}

.site-nav__list a:hover,
.site-nav__list a:focus-visible { color: var(--bone); }

.site-nav__list a:hover::after { transform: scaleX(1); }

.site-nav__list a[aria-current="page"] { color: var(--bone); }

.site-nav__list a[aria-current="page"]::after { transform: scaleX(1); }

.site-nav__cta { flex: none; }

html.nav-open { overflow: hidden; }

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--stand);
  border-top: 1px solid var(--steel);
  color: var(--bone);
}

.site-footer__banner {
  width: 100%;
  max-width: calc(var(--max) + var(--gutter) * 2);
  margin-inline: auto;
  padding: var(--s5) var(--gutter) var(--s4);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--s4);
  flex-wrap: wrap;
  border-bottom: 1px solid var(--concrete);
}

.site-footer__brand-mark {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: transparent;
  -webkit-text-stroke: 1px var(--steel);
}

.site-footer__banner-meta {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mist);
}

.site-footer__inner {
  width: 100%;
  max-width: calc(var(--max) + var(--gutter) * 2);
  margin-inline: auto;
  padding: var(--s7) var(--gutter) var(--s6);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--s6) var(--s5);
}

.site-footer__col { min-width: 0; }

.site-footer__col-title {
  margin: 0 0 var(--s4);
  padding-bottom: var(--s3);
  border-bottom: 1px solid var(--concrete);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 12px;
  line-height: 1;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--mist);
}

.site-footer__links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.site-footer__links a {
  display: inline-block;
  font-size: 14px;
  line-height: 1.6;
  color: var(--bone);
  text-decoration: none;
  transition: color 0.2s ease, transform 0.2s ease;
}

.site-footer__links a:hover {
  color: var(--red-bright);
  transform: translateX(2px);
}

.site-footer__text {
  margin: 0 0 var(--s2);
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
  word-break: break-word;
}

.site-footer__hours {
  margin: var(--s3) 0 0;
  padding-top: var(--s3);
  border-top: 1px dashed var(--concrete);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--amber);
}

.site-footer__baseline {
  width: 100%;
  max-width: calc(var(--max) + var(--gutter) * 2);
  margin-inline: auto;
  padding: var(--s4) var(--gutter);
  border-top: 1px solid var(--concrete);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s3);
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.site-footer__baseline-left { color: var(--steel); }

.site-footer__baseline-right {
  display: inline-flex;
  align-items: center;
  gap: var(--s2);
  flex-wrap: wrap;
}

/* ---------- 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s2);
  margin: 0 0 var(--s5);
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.breadcrumbs li { display: inline-flex; align-items: center; }

.breadcrumbs li + li::before {
  content: "/";
  margin-right: var(--s2);
  color: var(--concrete);
}

.breadcrumbs a {
  color: var(--mist);
  text-decoration: none;
  transition: color 0.2s ease;
}

.breadcrumbs a:hover { color: var(--bone); }

.breadcrumbs [aria-current="page"] { color: var(--bone); }

/* ---------- 栅格 ---------- */
.grid {
  display: grid;
  gap: var(--s5);
  grid-template-columns: minmax(0, 1fr);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }

/* ---------- 面板 / 标签 ---------- */
.panel {
  background: var(--stand);
  border: 1px solid var(--concrete);
  border-radius: var(--radius);
  padding: var(--s5);
}

.panel--flush { padding: 0; }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 8px;
  border: 1px solid var(--concrete);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.4;
  letter-spacing: 0.08em;
  color: var(--mist);
  white-space: nowrap;
}

.tag--ok {
  border-color: rgba(35, 224, 168, 0.42);
  color: var(--mint);
}

.tag--warn {
  border-color: rgba(245, 165, 36, 0.42);
  color: var(--amber);
}

.tag--alert {
  border-color: rgba(255, 74, 94, 0.42);
  color: var(--red-bright);
}

/* ---------- 编号章节 ---------- */
.section {
  padding: var(--s8) 0;
  border-top: 1px solid var(--concrete);
}

.section__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: end;
  gap: var(--s2) var(--s5);
  margin-bottom: var(--s6);
}

.section-index {
  font-family: var(--font-serif);
  font-size: clamp(48px, 7vw, 96px);
  font-weight: 600;
  line-height: 0.78;
  letter-spacing: -0.03em;
  color: var(--bone);
  opacity: 0.18;
  transition: opacity 0.3s ease;
  font-variant-numeric: tabular-nums;
  user-select: none;
}

[data-section].is-active .section-index { opacity: 1; }

.section__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(20px, 2.4vw, 28px);
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--bone);
  padding-bottom: 4px;
}

.section__lamp {
  display: inline-block;
  width: 8px;
  height: 8px;
  margin-right: var(--s2);
  border-radius: 50%;
  background: var(--concrete);
  vertical-align: middle;
  transition: background-color 0.28s ease, box-shadow 0.28s ease;
}

[data-section].is-active .section__lamp {
  background: var(--mint);
  box-shadow: 0 0 0 4px rgba(35, 224, 168, 0.12);
}

/* ---------- 文字段落 ---------- */
.eyebrow {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 12px;
  line-height: 1.4;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--red-bright);
}

.lede {
  max-width: 62ch;
  margin: 0 0 var(--s5);
  font-size: 18px;
  line-height: 1.72;
  color: var(--bone);
}

.prose {
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
}

.prose > * + * { margin-top: var(--s4); }

.prose p { margin: 0; }

.prose h2,
.prose h3 {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--bone);
  letter-spacing: 0.02em;
  line-height: 1.3;
}

.prose h2 { font-size: 22px; margin-top: var(--s6); }
.prose h3 { font-size: 17px; margin-top: var(--s5); }

.prose ul,
.prose ol { padding-left: 20px; }

.prose li + li { margin-top: 6px; }

.prose strong { color: var(--bone); font-weight: 500; }

.prose a { color: var(--red-bright); text-decoration: underline; text-underline-offset: 3px; }

.prose code {
  font-family: var(--font-mono);
  font-size: 0.9375em;
  letter-spacing: 0.06em;
  color: var(--mint);
  background: rgba(35, 224, 168, 0.08);
  padding: 1px 5px;
  border-radius: var(--radius);
}

/* ---------- 图片容器（页面阶段放入 <img>） ---------- */
.media {
  position: relative;
  overflow: hidden;
  display: block;
  width: 100%;
  background: var(--stand);
  border: 1px solid var(--concrete);
  border-radius: var(--radius);
  aspect-ratio: 16 / 9;
}

.media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3  { aspect-ratio: 4 / 3; }
.media--3x2  { aspect-ratio: 3 / 2; }
.media--1x1  { aspect-ratio: 1 / 1; }

/* 无图占位：看台条纹纹理 */
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    135deg,
    rgba(201, 203, 209, 0.05) 0 1px,
    transparent 1px 9px
  );
}

.media:has(img)::after { display: none; }

.media__caption {
  margin-top: var(--s2);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

/* ---------- 页尾动作条 ---------- */
.action-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s5);
  flex-wrap: wrap;
  padding: var(--s6) var(--gutter);
  background: var(--stand);
  border-top: 1px solid var(--steel);
}

.action-bar__text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 22px);
  letter-spacing: 0.04em;
  color: var(--bone);
  margin: 0;
}

/* ==========================================================================
   响应式
   ========================================================================== */

@media (max-width: 1120px) {
  :root { --gutter: 32px; }
  .site-nav { gap: var(--s5); }
  .site-nav__list { gap: 18px; }
}

@media (max-width: 960px) {
  :root { --header-h: 64px; }

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

  .site-nav {
    position: fixed;
    left: 0;
    right: 0;
    top: var(--header-h);
    margin: 0;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: var(--s4);
    padding: var(--s5) var(--gutter) var(--s6);
    background: var(--stand);
    border-bottom: 1px solid var(--steel);
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-8px);
    transition: opacity 0.22s ease, transform 0.22s ease, visibility 0.22s;
  }

  .site-nav[data-open="true"] {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
  }

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

  .site-nav__item + .site-nav__item { border-top: 1px solid var(--concrete); }

  .site-nav__list a {
    display: block;
    padding: 14px 0;
    font-size: 15px;
  }

  .site-nav__list a::after {
    left: 0;
    right: auto;
    width: 22px;
    bottom: 10px;
  }

  .site-nav__cta { width: 100%; margin-top: var(--s2); }

  .section { padding: var(--s7) 0; }

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

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

@media (max-width: 720px) {
  :root { --gutter: 20px; --header-h: 60px; }

  body { font-size: 15.5px; }

  .brand__name { font-size: 17px; letter-spacing: 0.14em; }

  .brand__state { display: none; }

  .section__head {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--s2);
  }

  .section-index { font-size: clamp(44px, 13vw, 64px); }

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

  .site-footer__inner { padding-top: var(--s6); }

  .site-footer__baseline {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--s2);
  }

  .action-bar {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--s4);
  }

  .action-bar .btn { width: 100%; }
}

@media (max-width: 560px) {
  .site-footer__grid { grid-template-columns: minmax(0, 1fr); }
  .site-footer__banner { align-items: flex-start; flex-direction: column; gap: var(--s2); }
  .panel { padding: var(--s4); }
}

/* ==========================================================================
   减弱动效
   ========================================================================== */
@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--live { animation: none; }

  .site-nav {
    transform: none !important;
  }

  .site-footer__links a:hover { transform: none; }

  .section-index { transition: none; }
}