/* ============================================================
   伟德主页 · 共享样式表  /assets/site.css
   档案室 / 航海日志视觉体系：近单色深蓝 + 铜金 + 状态时序色
   ============================================================ */

/* ---------- 01 变量 ---------- */
:root {
  --abyss-900: #0B1F2A;
  --abyss-800: #12303F;
  --abyss-700: #1B4155;
  --abyss-600: #2C5A72;
  --paper-100: #F4F1EA;
  --paper-200: #E7E1D4;
  --copper-500: #B87333;
  --copper-300: #D9A066;
  --ink-900: #101820;
  --ink-70: rgba(16, 24, 32, 0.72);
  --ink-50: rgba(16, 24, 32, 0.52);
  --rule: rgba(16, 24, 32, 0.14);
  --rule-strong: rgba(16, 24, 32, 0.28);
  --rule-dark: rgba(244, 241, 234, 0.16);
  --paper-70: rgba(244, 241, 234, 0.74);
  --paper-50: rgba(244, 241, 234, 0.52);

  --st-active: #2E8B74;
  --st-pending: #C98A2B;
  --st-archived: #5A6470;
  --st-active-ink: #1E6A57;
  --st-pending-ink: #8A5A12;
  --st-archived-ink: #4A545F;

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

  --wrap: 1240px;
  --gutter: clamp(18px, 4vw, 48px);
  --cut: 14px;
  --sp-1: 8px;
  --sp-2: 16px;
  --sp-3: 24px;
  --sp-4: 40px;
  --sp-5: 64px;
  --sp-6: 96px;
  --sticky-offset: 132px;
  --dur: 0.2s;
}

/* ---------- 02 重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body,
h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd, address { margin: 0; padding: 0; }

ul, ol { list-style: none; }

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

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

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

hr { border: 0; }

table { border-collapse: collapse; border-spacing: 0; }

/* ---------- 03 基础排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  color: var(--ink-900);
  background-color: var(--paper-100);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.22;
  letter-spacing: 0.005em;
}

h1 { font-size: clamp(2rem, 4.6vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h3 { font-size: clamp(1.125rem, 1.8vw, 1.375rem); }
h4 { font-size: 1.0625rem; }

p { max-width: 74ch; }

.mono,
code, kbd, samp { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

.lede {
  font-size: clamp(1rem, 1.4vw, 1.125rem);
  color: var(--ink-70);
  max-width: 64ch;
}

.prose > * + * { margin-top: 1em; }
.prose h2 { margin-top: 1.8em; }
.prose h3 { margin-top: 1.4em; }
.prose ul, .prose ol { padding-left: 1.2em; max-width: 70ch; }
.prose ul li { list-style: none; position: relative; padding-left: 1em; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0; top: 0.72em;
  width: 5px; height: 5px;
  background: var(--copper-500);
  transform: rotate(45deg);
}
.prose ol { list-style: decimal; }
.prose a { color: var(--abyss-600); text-decoration: underline; text-underline-offset: 3px; }
.prose a:hover { color: var(--copper-500); }
.prose strong { font-weight: 700; }

::selection { background: var(--copper-500); color: var(--ink-900); }

:focus-visible {
  outline: 2px solid var(--copper-500);
  outline-offset: 2px;
}

[id] { scroll-margin-top: var(--sticky-offset); }

.skip-link {
  position: absolute;
  top: 0; left: -9999px;
  z-index: 300;
  padding: 0.6rem 1rem;
  background: var(--copper-500);
  color: var(--ink-900);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
}
.skip-link:focus { left: 12px; top: 12px; }

.rule { height: 1px; background: var(--rule); margin: var(--sp-4) 0; }
.rule--dark { background: var(--rule-dark); }

/* ---------- 04 容器与栅格 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.section { padding: clamp(48px, 7vw, 96px) 0; position: relative; }
.section--paper2 { background: var(--paper-200); }
.section--band { background: var(--abyss-800); color: var(--paper-100); }
.section--dark { background: var(--abyss-900); color: var(--paper-100); }
.section--dark h1, .section--dark h2, .section--dark h3, .section--dark h4 { color: var(--paper-100); }
.section--dark p { color: var(--paper-70); }
.section--dark a { color: var(--copper-300); }
.section--dark a:hover { color: var(--paper-100); }

.grid { display: grid; gap: clamp(16px, 2.6vw, 36px); }
.grid--index { grid-template-columns: 240px minmax(0, 1fr); }
.grid--3-6-3 { grid-template-columns: 3fr 6fr 3fr; }
.grid--2-7-3 { grid-template-columns: 2fr 7fr 3fr; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--halves { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }

.index-col {
  position: sticky;
  top: var(--sticky-offset);
  align-self: start;
}

/* ---------- 05 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5em;
  padding: 0.72em 1.15em;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  line-height: 1.2;
  border: 1px solid transparent;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: background-color var(--dur) ease, color var(--dur) ease, border-color var(--dur) ease;
}

.btn--copper { background: var(--copper-500); color: var(--ink-900); }
.btn--copper:hover { background: var(--copper-300); }

.btn--line { border-color: var(--rule-strong); color: var(--ink-900); }
.btn--line:hover { border-color: var(--copper-500); color: var(--copper-500); }

.btn--ghost { border-color: var(--rule-dark); color: var(--paper-100); }
.btn--ghost:hover { border-color: var(--copper-300); color: var(--copper-300); }

.btn--sm { padding: 0.5em 0.9em; font-size: 0.75rem; }
.btn--block { display: flex; width: 100%; }

/* ---------- 06 状态徽标与标签 ---------- */
.status {
  display: inline-flex;
  align-items: center;
  gap: 0.45em;
  padding: 0.22em 0.6em;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  line-height: 1.6;
  border: 1px solid currentColor;
  white-space: nowrap;
}
.status::before {
  content: "";
  width: 6px; height: 6px;
  background: currentColor;
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}
.status--active { color: var(--st-active-ink); }
.status--pending { color: var(--st-pending-ink); }
.status--archived { color: var(--st-archived-ink); }
.section--dark .status--active, .section--band .status--active { color: #6FD1B4; }
.section--dark .status--pending, .section--band .status--pending { color: #E7B45C; }
.section--dark .status--archived, .section--band .status--archived { color: #A3ADB8; }

.tag-list { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.tag {
  display: inline-block;
  padding: 0.15em 0.55em;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
  color: var(--abyss-600);
  background: rgba(44, 90, 114, 0.08);
  border-left: 2px solid var(--abyss-600);
}
.section--dark .tag, .section--band .tag {
  color: var(--copper-300);
  background: rgba(217, 160, 102, 0.12);
  border-left-color: var(--copper-300);
}

/* ---------- 07 章节与卡片 ---------- */
.chapter {
  display: grid;
  grid-template-columns: minmax(0, auto) minmax(0, 1fr);
  gap: clamp(16px, 3vw, 40px);
  align-items: start;
  padding-top: var(--sp-3);
  margin-bottom: var(--sp-4);
  border-top: 1px solid var(--rule);
}
.chapter--dark { border-top-color: var(--rule-dark); }
.chapter__num {
  font-family: var(--font-mono);
  font-size: clamp(2.5rem, 7vw, 5.5rem);
  font-weight: 600;
  line-height: 0.85;
  letter-spacing: -0.03em;
  color: var(--copper-500);
  font-variant-numeric: tabular-nums;
}
.chapter--dark .chapter__num { color: var(--copper-300); }
.chapter__title { font-size: clamp(1.5rem, 3vw, 2.25rem); }
.chapter__lede {
  margin-top: 0.75rem;
  max-width: 62ch;
  color: var(--ink-70);
}
.chapter--dark .chapter__lede { color: var(--paper-70); }
.chapter__body > * + * { margin-top: var(--sp-3); }

.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  background: var(--paper-200);
  border: 1px solid var(--rule);
  transition: transform var(--dur) ease, border-color var(--dur) ease, box-shadow var(--dur) ease;
}
.card:hover {
  transform: translateY(-2px);
  border-color: var(--copper-300);
  box-shadow: 0 10px 24px rgba(11, 31, 42, 0.09);
}
.card--cut {
  clip-path: polygon(
    0 0,
    calc(100% - var(--cut)) 0,
    100% var(--cut),
    100% 100%,
    var(--cut) 100%,
    0 calc(100% - var(--cut))
  );
}
.card--dry { background: transparent; border-color: var(--rule-strong); }
.card__flag {
  position: absolute;
  left: 0; top: 0;
  width: 4px; height: 34px;
  background: var(--copper-500);
  transition: height var(--dur) ease;
}
.card:hover .card__flag { height: 60px; }
.card__meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--ink-50);
}
.card__title { margin-top: 0.5rem; }
.card__text { margin-top: 0.5rem; color: var(--ink-70); font-size: 0.9375rem; }
.card__foot {
  margin-top: var(--sp-3);
  padding-top: 0.75rem;
  border-top: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
}
.section--dark .card, .section--band .card {
  background: var(--abyss-800);
  border-color: var(--rule-dark);
  color: var(--paper-100);
}
.section--dark .card__text { color: var(--paper-70); }
.section--dark .card__meta { color: var(--paper-50); }
.section--dark .card__foot { border-top-color: var(--rule-dark); }

.timeline { position: relative; padding-left: clamp(24px, 4vw, 40px); }
.timeline::before {
  content: "";
  position: absolute;
  left: 6px; top: 6px; bottom: 6px;
  width: 1px;
  background: repeating-linear-gradient(180deg, var(--rule-strong) 0 6px, transparent 6px 12px);
}
.timeline__item { position: relative; padding-bottom: var(--sp-4); }
.timeline__item:last-child { padding-bottom: 0; }
.timeline__item::before {
  content: "";
  position: absolute;
  left: calc(-1 * clamp(24px, 4vw, 40px) + 1px);
  top: 8px;
  width: 11px; height: 11px;
  background: var(--paper-100);
  border: 2px solid var(--copper-500);
  transform: rotate(45deg);
}
.section--dark .timeline__item::before { background: var(--abyss-900); }
.timeline__meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--ink-50);
}
.section--dark .timeline__meta { color: var(--paper-50); }
.timeline__title { margin-top: 0.35rem; font-size: 1.125rem; }
.timeline__text { margin-top: 0.35rem; color: var(--ink-70); }

.stat { display: flex; flex-direction: column; gap: 0.2rem; }
.stat__value {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 2.6vw, 2.125rem);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
}
.stat__unit { font-size: 0.75em; color: var(--ink-50); margin-left: 0.25em; }
.stat__label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  color: var(--ink-50);
}
.section--dark .stat__unit, .section--dark .stat__label { color: var(--paper-50); }

.notice {
  padding: var(--sp-3);
  background: rgba(184, 115, 51, 0.08);
  border-left: 3px solid var(--copper-500);
}
.notice__label {
  display: block;
  margin-bottom: 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  color: var(--copper-500);
}
.notice p { color: var(--ink-70); font-size: 0.9375rem; }

/* ---------- 08 参数表 ---------- */
.table-scroll {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--rule);
  background: var(--paper-100);
  -webkit-overflow-scrolling: touch;
}
.table-scroll--sticky { max-height: 70vh; overflow-y: auto; }

.data-table {
  width: 100%;
  min-width: 640px;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-variant-numeric: tabular-nums;
}
.data-table caption {
  padding: 0.75rem 1rem;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--ink-50);
  border-bottom: 1px solid var(--rule);
}
.data-table th,
.data-table td {
  padding: 0.7rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}
.data-table thead th {
  position: sticky;
  top: 0;
  z-index: 2;
  background: var(--abyss-700);
  color: var(--paper-100);
  font-weight: 500;
  letter-spacing: 0.08em;
  white-space: nowrap;
}
.data-table tbody tr:nth-child(even) { background: rgba(231, 225, 212, 0.55); }
.data-table tbody tr:hover { background: rgba(217, 160, 102, 0.16); }
.data-table__num { text-align: right; }
.data-table tbody th { font-weight: 500; color: var(--ink-900); }

/* ---------- 09 面包屑与锚点索引 ---------- */
.breadcrumbs { padding: 0.9rem 0; border-bottom: 1px solid var(--rule); }
.breadcrumbs__list { display: flex; flex-wrap: wrap; align-items: center; gap: 0.4rem; }
.breadcrumbs__item {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--ink-50);
}
.breadcrumbs__link { color: var(--abyss-600); }
.breadcrumbs__link:hover { color: var(--copper-500); }
.breadcrumbs__item[aria-current="page"] { color: var(--ink-900); }
.breadcrumbs__sep { color: var(--rule-strong); }

.anchor-nav { border-top: 1px solid var(--rule); padding-top: 0.75rem; }
.anchor-nav__title {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  color: var(--copper-500);
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--rule);
}
.anchor-nav__list { margin-top: 0.5rem; }
.anchor-nav__link {
  display: block;
  padding: 0.45rem 0.5rem 0.45rem 0.75rem;
  border-left: 2px solid transparent;
  font-size: 0.875rem;
  color: var(--ink-70);
  transition: color var(--dur) ease, border-color var(--dur) ease, background-color var(--dur) ease;
}
.anchor-nav__link:hover { color: var(--ink-900); background: rgba(184, 115, 51, 0.08); }
.anchor-nav__link[aria-current="true"] {
  color: var(--ink-900);
  border-left-color: var(--copper-500);
  background: rgba(184, 115, 51, 0.1);
}

/* ---------- 10 图片容器（页面阶段放置占位） ---------- */
.figure {
  position: relative;
  background: var(--paper-200);
  border: 1px solid var(--rule);
}
.figure__media {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: linear-gradient(135deg, var(--abyss-800), var(--abyss-600));
}
.figure__media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(115deg, transparent 0 18px, rgba(217, 160, 102, 0.18) 18px 19px);
}
.figure__media--square { aspect-ratio: 1 / 1; }
.figure__media--tall { aspect-ratio: 4 / 5; }
.figure__media--wide { aspect-ratio: 21 / 9; }
.figure__img { width: 100%; height: 100%; object-fit: cover; }
.figure__caption {
  padding: 0.7rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--ink-70);
  border-top: 1px solid var(--rule);
}
.section--dark .figure, .section--band .figure { border-color: var(--rule-dark); }
.section--dark .figure__caption, .section--band .figure__caption { color: var(--paper-70); border-top-color: var(--rule-dark); }

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

/* ---------- 11 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: var(--abyss-900);
  color: var(--paper-100);
  box-shadow: 0 1px 0 rgba(244, 241, 234, 0.1), 0 12px 28px rgba(11, 31, 42, 0.16);
}

.util-bar {
  background: var(--abyss-900);
  border-bottom: 1px solid var(--rule-dark);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}
.util-bar__inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0.45rem var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.util-bar__tagline {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  max-width: none;
  color: var(--paper-50);
}
.util-bar__sigil {
  width: 10px; height: 10px;
  flex: 0 0 auto;
  background: var(--copper-500);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 68% 100%, 0 100%);
}
.util-nav { display: flex; align-items: center; gap: clamp(12px, 2vw, 24px); }
.util-nav__list { display: flex; align-items: center; gap: clamp(10px, 1.6vw, 20px); }
.util-nav__link {
  padding: 0.2rem 0;
  color: var(--paper-70);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) ease, border-color var(--dur) ease;
}
.util-nav__link:hover { color: var(--paper-100); border-bottom-color: var(--copper-300); }
.util-bar__cta { flex: 0 0 auto; }

.nav-bar { background: var(--abyss-800); }
.nav-bar__inner {
  position: relative;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0.7rem var(--gutter);
  display: flex;
  align-items: center;
  gap: clamp(16px, 3vw, 40px);
}

.brand { display: flex; align-items: center; gap: 0.75rem; flex: 0 0 auto; }
.brand__mark {
  width: 38px; height: 38px;
  display: grid;
  place-items: center;
  background: var(--copper-500);
  color: var(--ink-900);
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%);
}
.brand__text { display: flex; flex-direction: column; }
.brand__name {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.04em;
  color: var(--paper-100);
}
.brand__sub {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  color: var(--paper-50);
}

.site-nav { margin-left: auto; }
.site-nav__list { display: flex; align-items: center; gap: clamp(4px, 1.2vw, 16px); }
.site-nav__item { display: flex; }
.site-nav__link {
  display: flex;
  flex-direction: column;
  gap: 1px;
  padding: 0.35rem 0.55rem;
  font-size: 0.9375rem;
  color: var(--paper-70);
  border-bottom: 2px solid transparent;
  transition: color var(--dur) ease, background-color var(--dur) ease, border-color var(--dur) ease;
}
.site-nav__num {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.16em;
  color: var(--copper-300);
  opacity: 0.75;
}
.site-nav__text { white-space: nowrap; }
.site-nav__link:hover {
  color: #FFFFFF;
  background: rgba(244, 241, 234, 0.07);
  border-bottom-color: var(--copper-300);
}
.site-nav__link[aria-current="page"] {
  color: #FFFFFF;
  border-bottom-color: var(--copper-500);
}
.site-nav__link[aria-current="page"] .site-nav__num { opacity: 1; color: var(--copper-500); }

.nav-toggle { display: none; }

/* ---------- 12 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 96px);
  background: var(--abyss-900);
  color: var(--paper-70);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--copper-500) 0 18%, rgba(184, 115, 51, 0.16) 18% 100%);
}
.site-footer__inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: clamp(40px, 6vw, 72px) var(--gutter) clamp(24px, 4vw, 36px);
}
.site-footer__grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.2fr;
  gap: clamp(24px, 3vw, 48px);
}

.footer-brand__mark {
  width: 44px; height: 44px;
  display: grid;
  place-items: center;
  background: var(--copper-500);
  color: var(--ink-900);
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 700;
  line-height: 1;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
}
.footer-brand__name {
  margin-top: 0.85rem;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--paper-100);
  max-width: none;
}
.footer-brand__tagline {
  margin-top: 0.2rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--copper-300);
  max-width: none;
}
.footer-brand__note {
  margin-top: 0.85rem;
  max-width: 34ch;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--paper-50);
}

.footer-col__title {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  color: var(--copper-300);
  padding-bottom: 0.5rem;
  margin-bottom: 0.6rem;
  border-bottom: 1px solid var(--rule-dark);
  max-width: none;
}
.footer-col__link {
  display: inline-block;
  padding: 0.32rem 0;
  font-size: 0.9rem;
  color: var(--paper-70);
  transition: color var(--dur) ease, transform var(--dur) ease;
}
.footer-col__link:hover {
  color: #FFFFFF;
  transform: translateX(3px);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--copper-500);
}

.footer-contact__list { display: grid; gap: 0.45rem; }
.footer-contact__row {
  display: grid;
  grid-template-columns: 3.2rem minmax(0, 1fr);
  gap: 0.5rem;
  align-items: baseline;
}
.footer-contact__label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  color: var(--paper-50);
}
.footer-contact__value {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--paper-70);
  word-break: break-word;
}

.site-footer__base {
  margin-top: clamp(32px, 5vw, 56px);
  padding-top: 1rem;
  border-top: 1px solid var(--rule-dark);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  font-size: 0.75rem;
  color: var(--paper-50);
}
.footer-meta, .footer-icp { max-width: none; letter-spacing: 0.06em; }

/* ---------- 13 交互动效 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.45s ease, transform 0.45s ease;
}
[data-reveal].is-revealed { opacity: 1; transform: none; }

.scroll-meter {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 2px;
  z-index: 200;
  pointer-events: none;
  background: transparent;
}
.scroll-meter__bar {
  height: 100%;
  width: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background: linear-gradient(90deg, var(--copper-500), var(--copper-300));
}

.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 32px);
  bottom: clamp(14px, 3vw, 32px);
  z-index: 180;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 0.85rem;
  background: var(--abyss-800);
  color: var(--paper-100);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  border: 1px solid var(--rule-dark);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--dur) ease, transform var(--dur) ease, visibility var(--dur) ease, background-color var(--dur) ease;
}
.to-top.is-visible { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { background: var(--abyss-700); }
.to-top__arrow {
  width: 0; height: 0;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-bottom: 6px solid var(--copper-300);
}

/* ---------- 14 响应式 ---------- */
@media (max-width: 1080px) {
  .grid--3-6-3, .grid--2-7-3 { grid-template-columns: 220px minmax(0, 1fr); }
  .site-footer__grid { grid-template-columns: 1.4fr 1fr 1fr; }
  .footer-col--contact { grid-column: 1 / -1; }
  .footer-contact__list { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
}

@media (max-width: 980px) {
  :root { --sticky-offset: 96px; }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.55rem;
    margin-left: auto;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--rule-dark);
    color: var(--paper-100);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.12em;
    transition: border-color var(--dur) ease, color var(--dur) ease;
  }
  .nav-toggle:hover { border-color: var(--copper-300); color: var(--copper-300); }
  .nav-toggle__bars { display: grid; gap: 4px; width: 16px; }
  .nav-toggle__bars span {
    display: block;
    height: 2px;
    background: currentColor;
    transition: transform var(--dur) ease, opacity var(--dur) ease;
  }
  .nav-toggle__label { line-height: 1; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    margin-left: 0;
    background: var(--abyss-900);
    border-top: 1px solid var(--rule-dark);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.26s ease;
  }
  .site-header[data-open] .site-nav {
    max-height: min(72vh, 540px);
    overflow-y: auto;
  }
  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.25rem 0 0.75rem;
  }
  .site-nav__item { display: block; }
  .site-nav__link {
    flex-direction: row;
    align-items: baseline;
    gap: 0.85rem;
    padding: 0.95rem var(--gutter);
    font-size: 1rem;
    border-bottom: 1px solid var(--rule-dark);
    border-left: 2px solid transparent;
  }
  .site-nav__link:hover { background: rgba(244, 241, 234, 0.06); border-bottom-color: var(--rule-dark); border-left-color: var(--copper-300); }
  .site-nav__link[aria-current="page"] {
    background: rgba(184, 115, 51, 0.12);
    border-left-color: var(--copper-500);
    border-bottom-color: var(--rule-dark);
  }
  .site-header[data-open] .nav-toggle__bars span:first-child { transform: translateY(3px) rotate(45deg); }
  .site-header[data-open] .nav-toggle__bars span:last-child { transform: translateY(-3px) rotate(-45deg); }

  .grid--index, .grid--3-6-3, .grid--2-7-3,
  .grid--2, .grid--3, .grid--halves { grid-template-columns: minmax(0, 1fr); }
  .index-col { position: static; top: auto; }
}

@media (max-width: 720px) {
  .util-bar__tagline { display: none; }
  .util-nav { width: 100%; justify-content: space-between; }
  .chapter { grid-template-columns: minmax(0, 1fr); gap: 0.5rem; }
  .chapter__num { font-size: clamp(2.25rem, 14vw, 3.5rem); }
  .site-footer__grid { grid-template-columns: minmax(0, 1fr); }
  .footer-col--contact { grid-column: auto; }
  .footer-contact__list { grid-template-columns: minmax(0, 1fr); }
  .to-top__label { display: none; }
  .to-top { padding: 0.6rem 0.7rem; }
}

@media (max-width: 460px) {
  .util-nav__list { gap: 0.75rem; }
  .brand__sub { display: none; }
  .btn { letter-spacing: 0.06em; }
}

/* ---------- 15 可访问性与动效偏好 ---------- */
@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;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .card:hover { transform: none; }
  .footer-col__link:hover { transform: none; }
  .to-top { transform: none; }
}

@media print {
  .site-header, .site-footer, .to-top, .scroll-meter { display: none; }
  body { background: #FFFFFF; color: #000000; }
}