/* ==========================================================================
   全站EMC品牌站 — /assets/site.css
   共享外壳：侧边轨道头部、页脚、通用排版与基础组件
   ========================================================================== */

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

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

body { margin: 0; }

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

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

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

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

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

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

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

[hidden] { display: none !important; }

/* ---------------------------------------------------------------
   2. Design tokens
   --------------------------------------------------------------- */
:root {
  --paper: #FBF5EC;
  --ink: #14110F;
  --blue: #0057B8;
  --orange: #FF6B35;
  --orange-ink: #A8461F;
  --mist: #DCE4EE;
  --deep: #1F4E8C;
  --warm: #6B6259;
  --rule: #E8DECD;
  --glass: rgba(255, 255, 255, 0.72);

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

  --rail-w: 236px;
  --shell: min(1180px, 100% - 2.5rem);
  --radius: 16px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

:root[data-rail="collapsed"] { --rail-w: 96px; }

/* ---------------------------------------------------------------
   3. Base typography (中文排版)
   --------------------------------------------------------------- */
body {
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 500;
  line-height: 1.75;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.12;
  color: var(--ink);
}

h1 { font-size: clamp(2rem, 4.6vw, 3.5rem); line-height: 1.06; }
h2 { font-size: clamp(1.45rem, 2.4vw, 2.1rem); }
h3 { font-size: 1.15rem; line-height: 1.4; letter-spacing: -0.01em; }
h4 { font-size: 0.95rem; letter-spacing: 0; }

strong, b { font-weight: 800; }

code, .mono { font-family: var(--font-mono); }

::selection { background: var(--orange); color: var(--ink); }

:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: 3px;
  border-radius: 3px;
}

/* ---------------------------------------------------------------
   4. Utilities
   --------------------------------------------------------------- */
.skip-link {
  position: fixed;
  left: 1rem;
  top: -120px;
  z-index: 300;
  display: inline-block;
  padding: 0.7rem 1.15rem;
  background: var(--orange);
  color: var(--ink);
  font-weight: 800;
  font-size: 0.85rem;
  border-radius: 0 0 12px 12px;
  transition: top 0.2s var(--ease);
}
.skip-link:focus { top: 0; }

.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;
}

.shell {
  width: var(--shell);
  margin-inline: auto;
}

.prose { max-width: 38em; }
.prose p + p { margin-top: 1.1em; }

.grid { display: grid; gap: clamp(1rem, 2.2vw, 2rem); }
@media (min-width: 760px) {
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .grid--editorial {
    grid-template-columns: minmax(0, 7fr) minmax(0, 3fr);
    gap: clamp(1.75rem, 3.5vw, 3.25rem);
  }
}

/* ---------------------------------------------------------------
   5. 通用组件
   --------------------------------------------------------------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--orange-ink);
}
.eyebrow::before {
  content: "";
  width: 20px;
  height: 2px;
  background: var(--orange);
  flex: none;
}

.lede {
  font-size: clamp(1.05rem, 1.6vw, 1.3rem);
  line-height: 1.72;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--ink);
  max-width: 30em;
}

.index-number {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--orange-ink);
  margin-bottom: 0.45rem;
}

.marginnote {
  border-left: 2px solid var(--blue);
  padding-left: 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  line-height: 1.7;
  letter-spacing: 0.01em;
  color: var(--warm);
}
.marginnote a { color: var(--blue); border-bottom: 1px solid var(--rule); }

.rule {
  border: 0;
  border-top: 1px solid var(--rule);
  margin-block: clamp(1.5rem, 3vw, 2.5rem);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.72rem 1.3rem;
  border-radius: 999px;
  border: 1.5px solid transparent;
  font-size: 0.88rem;
  font-weight: 800;
  letter-spacing: 0.01em;
  line-height: 1;
  white-space: nowrap;
  transition: transform 0.18s var(--ease), background-color 0.18s var(--ease),
              color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.btn--signal {
  background: var(--orange);
  border-color: var(--orange);
  color: var(--ink);
}
.btn--signal:hover { background: #ff8659; border-color: #ff8659; transform: translateY(-2px); }
.btn--solid {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}
.btn--solid:hover { background: var(--deep); border-color: var(--deep); transform: translateY(-2px); }
.btn--ghost {
  background: transparent;
  border-color: currentColor;
  color: inherit;
}
.btn--ghost:hover { background: rgba(255, 107, 53, 0.14); border-color: var(--orange); transform: translateY(-2px); }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.95rem;
  border-radius: 999px;
  border: 1.5px solid var(--rule);
  background: var(--glass);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--warm);
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease),
              border-color 0.18s var(--ease), transform 0.18s var(--ease);
}
.chip:hover { border-color: var(--blue); color: var(--blue); transform: translateY(-2px); }
.chip[aria-pressed="true"],
.chip.is-active {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}

.card {
  background: var(--glass);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: clamp(1rem, 2vw, 1.5rem);
  transition: transform 0.18s var(--ease), border-color 0.18s var(--ease);
}
.card:hover { transform: translateY(-2px); border-color: var(--blue); }

.band {
  background: var(--mist);
  border-block: 1px solid var(--rule);
  padding-block: clamp(1.6rem, 3.2vw, 2.75rem);
}

.breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--warm);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.55rem;
}
.breadcrumb li { display: flex; align-items: center; gap: 0.55rem; }
.breadcrumb li:not(:last-child)::after { content: "/"; color: var(--rule); }
.breadcrumb a:hover { color: var(--blue); }

/* 图片容器基础规则 —— 页面阶段替换为实际图形 */
.figure {
  position: relative;
  margin: 0;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--mist);
  border: 1px solid var(--rule);
}
.figure img,
.figure svg { width: 100%; height: 100%; object-fit: cover; }
.figure--band { aspect-ratio: 8 / 3; }
.figure--wide { aspect-ratio: 16 / 9; }
.figure--std { aspect-ratio: 3 / 2; }
.figure__ph {
  position: absolute;
  inset: 0;
  background:
    repeating-linear-gradient(135deg, rgba(0, 87, 184, 0.09) 0 2px, transparent 2px 12px);
}
.figure__caption {
  margin-top: 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.04em;
  color: var(--warm);
}

/* ---------------------------------------------------------------
   6. Header — 侧边轨道
   --------------------------------------------------------------- */
.rail {
  position: sticky;
  top: 0;
  z-index: 90;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  padding: 0.75rem 1rem 0.65rem;
  background: var(--ink);
  color: var(--paper);
  border-bottom: 1px solid rgba(251, 245, 236, 0.14);
}

.rail__collapse {
  position: absolute;
  top: 1.7rem;
  right: -13px;
  z-index: 4;
  display: none;
  place-items: center;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--blue);
  color: #fff;
  border: 2px solid var(--paper);
  font-size: 0.72rem;
  line-height: 1;
  transition: background-color 0.18s var(--ease), transform 0.18s var(--ease);
}
.rail__collapse:hover { background: var(--orange); color: var(--ink); }
.rail__collapse-icon { display: block; line-height: 1; transition: transform 0.3s var(--ease); }
:root[data-rail="collapsed"] .rail__collapse-icon { transform: rotate(180deg); }

.rail__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  min-width: 0;
}

.rail__brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  min-width: 0;
}
.rail__mark {
  flex: none;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--blue);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.16) inset;
}
.rail__brandtext { display: flex; flex-direction: column; min-width: 0; }
.rail__brandline {
  font-size: 0.98rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  white-space: nowrap;
  color: var(--paper);
}
.rail__tagline {
  font-size: 0.7rem;
  line-height: 1.5;
  color: rgba(251, 245, 236, 0.6);
  max-width: 17em;
}

.rail__burger {
  display: none;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.8rem;
  border: 1px solid rgba(251, 245, 236, 0.26);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--paper);
  transition: border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.rail__burger:hover { border-color: var(--orange); background: rgba(255, 107, 53, 0.12); }
.rail__burger-icon {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 16px;
  height: 11px;
  flex: none;
}
.rail__burger-icon span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.22s var(--ease), opacity 0.16s var(--ease);
}
.rail__burger[aria-expanded="true"] .rail__burger-icon span:nth-child(1) { transform: translateY(4.5px) rotate(45deg); }
.rail__burger[aria-expanded="true"] .rail__burger-icon span:nth-child(2) { opacity: 0; }
.rail__burger[aria-expanded="true"] .rail__burger-icon span:nth-child(3) { transform: translateY(-4.5px) rotate(-45deg); }

.rail__steps {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.12em;
}
.rail__step {
  display: flex;
  align-items: center;
  gap: 0.38rem;
  color: rgba(251, 245, 236, 0.62);
}
.rail__step + .rail__step::before {
  content: "";
  width: 14px;
  height: 2px;
  background: rgba(0, 87, 184, 0.85);
  margin-right: 0.38rem;
}
.rail__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--orange);
  flex: none;
}
.rail__step-text { white-space: nowrap; }

.rail__panel {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  flex: 1 1 auto;
  min-height: 0;
}

.rail__search { display: flex; flex-direction: column; gap: 0.35rem; }
.rail__searchlabel {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(251, 245, 236, 0.5);
}
.rail__input {
  width: 100%;
  padding: 0.55rem 0.7rem;
  border-radius: 10px;
  border: 1px solid rgba(251, 245, 236, 0.22);
  background: rgba(251, 245, 236, 0.06);
  color: var(--paper);
  font-size: 0.8rem;
  line-height: 1.5;
  transition: border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.rail__input::placeholder { color: rgba(251, 245, 236, 0.38); }
.rail__input:focus {
  border-color: var(--orange);
  background: rgba(251, 245, 236, 0.1);
}
.rail__input::-webkit-search-cancel-button { filter: invert(1); opacity: 0.5; }
.rail__hint {
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.04em;
  color: var(--orange);
}

.rail__nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-height: 0;
  overflow-y: auto;
  padding-right: 2px;
  scrollbar-width: thin;
  scrollbar-color: rgba(251, 245, 236, 0.22) transparent;
}
.rail__nav::-webkit-scrollbar { width: 4px; }
.rail__nav::-webkit-scrollbar-thumb { background: rgba(251, 245, 236, 0.22); border-radius: 2px; }

.rail__link {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.48rem 0.6rem;
  border-radius: 9px;
  border-left: 2px solid transparent;
  font-size: 0.89rem;
  font-weight: 600;
  color: rgba(251, 245, 236, 0.74);
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease),
              border-color 0.18s var(--ease), opacity 0.2s var(--ease);
}
.rail__link:hover { background: rgba(251, 245, 236, 0.09); color: var(--paper); }
.rail__link[aria-current="page"] {
  background: rgba(0, 87, 184, 0.32);
  border-left-color: var(--orange);
  color: #fff;
}
.rail__link.is-dim { opacity: 0.26; }

.rail__num {
  flex: none;
  width: 1.7em;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: rgba(251, 245, 236, 0.42);
}
.rail__link[aria-current="page"] .rail__num { color: var(--orange); }
.rail__label { min-width: 0; }

.rail__foot {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  padding-top: 0.75rem;
  border-top: 1px solid rgba(251, 245, 236, 0.14);
}
.rail__note {
  font-family: var(--font-mono);
  font-size: 0.64rem;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: rgba(251, 245, 236, 0.48);
}
.rail__progress {
  height: 3px;
  border-radius: 2px;
  background: rgba(251, 245, 236, 0.16);
  overflow: hidden;
}
.rail__progress span {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background: linear-gradient(90deg, var(--blue), var(--orange));
  transition: transform 0.1s linear;
}

/* 折叠态 */
:root[data-rail="collapsed"] .rail__top { justify-content: center; }
:root[data-rail="collapsed"] .rail__brandtext,
:root[data-rail="collapsed"] .rail__tagline,
:root[data-rail="collapsed"] .rail__steps,
:root[data-rail="collapsed"] .rail__search,
:root[data-rail="collapsed"] .rail__note,
:root[data-rail="collapsed"] .rail__label { display: none; }
:root[data-rail="collapsed"] .rail__link { justify-content: center; padding-inline: 0; }
:root[data-rail="collapsed"] .rail__num { width: auto; }

/* ---------------------------------------------------------------
   7. Footer
   --------------------------------------------------------------- */
.site-footer {
  margin-top: clamp(3rem, 6vw, 6rem);
  background: var(--ink);
  color: rgba(251, 245, 236, 0.78);
  border-top: 3px solid var(--blue);
}

.site-footer__inner {
  width: var(--shell);
  margin-inline: auto;
  display: grid;
  gap: clamp(1.75rem, 3.5vw, 3rem);
  padding-block: clamp(2.25rem, 4.5vw, 3.75rem);
}
@media (min-width: 760px) {
  .site-footer__inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 1024px) {
  .site-footer__inner {
    grid-template-columns: minmax(0, 4fr) minmax(0, 2fr) minmax(0, 2fr) minmax(0, 3fr);
  }
}

.site-footer__brand { min-width: 0; }
.site-footer__logo {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 800;
  color: var(--paper);
}
.site-footer__mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background: var(--blue);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.06em;
  flex: none;
}
.site-footer__name { font-size: 1rem; letter-spacing: -0.01em; }
.site-footer__intro {
  margin-top: 1rem;
  font-size: 0.87rem;
  line-height: 1.85;
  color: rgba(251, 245, 236, 0.62);
  max-width: 34em;
}
.site-footer__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.25rem;
}

.site-footer__col { min-width: 0; }
.site-footer__heading {
  margin-bottom: 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: rgba(251, 245, 236, 0.45);
}
.site-footer__list { display: flex; flex-direction: column; gap: 0.55rem; }
.site-footer__list a {
  display: inline-block;
  font-size: 0.87rem;
  color: rgba(251, 245, 236, 0.78);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.site-footer__list a:hover {
  color: var(--paper);
  border-bottom-color: var(--orange);
}

.site-footer__contact { min-width: 0; }
.site-footer__contact-list {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}
.site-footer__contact-list li {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  min-width: 0;
}
.site-footer__k {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(251, 245, 236, 0.4);
}
.site-footer__v {
  font-family: var(--font-mono);
  font-size: 0.79rem;
  line-height: 1.6;
  color: rgba(251, 245, 236, 0.84);
  word-break: break-word;
}
.site-footer__note {
  margin-top: 0.95rem;
  padding-left: 0.7rem;
  border-left: 2px solid var(--orange);
  font-size: 0.72rem;
  line-height: 1.75;
  color: rgba(251, 245, 236, 0.44);
}

.site-footer__base { border-top: 1px solid rgba(251, 245, 236, 0.12); }
.site-footer__base-inner {
  width: var(--shell);
  margin-inline: auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.6rem 1.5rem;
  padding-block: 1.1rem;
}
.site-footer__legal {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.07em;
  color: rgba(251, 245, 236, 0.46);
}

/* ---------------------------------------------------------------
   8. 主体占位
   --------------------------------------------------------------- */
#main-content {
  display: block;
  padding-block: clamp(1.5rem, 4vw, 3rem);
}

/* ---------------------------------------------------------------
   9. 桌面端轨道布局 ≥1024px
   --------------------------------------------------------------- */
@media (min-width: 1024px) {
  body {
    padding-left: var(--rail-w);
    transition: padding-left 0.3s var(--ease);
  }

  .rail {
    position: fixed;
    inset: 0 auto 0 0;
    width: var(--rail-w);
    height: 100vh;
    height: 100dvh;
    z-index: 90;
    padding: 1.4rem 1rem 1.2rem;
    border-bottom: 0;
    border-right: 1px solid rgba(251, 245, 236, 0.1);
    transition: width 0.3s var(--ease);
  }

  .rail__collapse { display: grid; }
  .rail__panel { overflow: hidden; }
}

/* ---------------------------------------------------------------
   10. 移动端抽屉 ≤1023.98px
   --------------------------------------------------------------- */
@media (max-width: 1023.98px) {
  html[data-nav="open"] { overflow: hidden; }

  html[data-nav="open"] body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: 80;
    background: rgba(20, 17, 15, 0.55);
  }

  .rail__burger { display: inline-flex; }

  .rail__panel {
    position: fixed;
    inset: 0 0 0 auto;
    z-index: 85;
    width: min(340px, 86vw);
    padding: 5.5rem 1.25rem 1.5rem;
    background: var(--ink);
    border-left: 1px solid rgba(251, 245, 236, 0.14);
    overflow-y: auto;
    transform: translateX(102%);
    transition: transform 0.32s var(--ease);
  }
  .rail__panel[data-open="true"] { transform: translateX(0); }

  .rail__nav { overflow: visible; }
  .rail__link { padding-block: 0.62rem; font-size: 0.95rem; }
  .rail__foot { margin-top: 1.25rem; }
}

/* ---------------------------------------------------------------
   11. Reduced motion
   --------------------------------------------------------------- */
@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;
  }

  .btn:hover,
  .chip:hover,
  .card:hover { transform: none; }
  .rail__panel { transition: none; }
}