/* ==========================================================================
   宝威体育站 · /assets/site.css
   共享外壳：框架式头部 / 堆叠式页脚 / 通用版式与基础组件
   ========================================================================== */

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

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

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

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

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

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

/* 2. 设计变量
   ========================================================================== */
:root {
  /* 色彩 */
  --ink: #071A16;
  --panel: #0E2B24;
  --card: #163B31;
  --cyan: #2FF3D0;
  --orange: #FF7A1A;
  --paper: #F4EFE3;
  --muted: #A8BBB2;
  --rule: #6F857B;
  --cyan-soft: #8FD8C7;
  --orange-soft: #FFB37A;

  --line: rgba(111, 133, 123, 0.42);
  --line-soft: rgba(111, 133, 123, 0.22);
  --line-strong: rgba(111, 133, 123, 0.72);
  --cyan-wash: rgba(47, 243, 208, 0.08);
  --cyan-wash-strong: rgba(47, 243, 208, 0.16);
  --orange-wash: rgba(255, 122, 26, 0.12);

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

  /* 字号 */
  --step--1: 0.8125rem;
  --step-0: 1rem;
  --step-1: clamp(1.02rem, 1.1vw, 1.125rem);
  --step-2: clamp(1.28rem, 2vw, 1.6rem);
  --step-3: clamp(1.62rem, 3vw, 2.35rem);
  --step-4: clamp(2.05rem, 4.5vw, 3.5rem);
  --step-5: clamp(2.8rem, 8vw, 6.5rem);
  --step-chapter: clamp(3.5rem, 12vw, 9rem);

  /* 结构 */
  --bar-h: 4.5rem;
  --nav-h: 3.1rem;
  --frame-h: calc(var(--bar-h) + var(--nav-h));
  --gutter: clamp(1rem, 3vw, 2.5rem);
  --wrap: 1360px;
  --radius: 2px;
}

/* 3. 基础排版
   ========================================================================== */
html {
  background: var(--ink);
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--frame-h) + 1.25rem);
}

body {
  min-height: 100vh;
  padding-top: var(--frame-h);
  background-color: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: var(--step-1);
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: 0.01em;
  color: var(--paper);
}

h1 { font-size: var(--step-5); line-height: 0.94; letter-spacing: -0.005em; }
h2 { font-size: var(--step-4); }
h3 { font-size: var(--step-3); }
h4 { font-size: var(--step-2); }

a {
  color: var(--cyan-soft);
  text-decoration: none;
  transition: color 0.18s ease;
}
a:hover { color: var(--cyan); }

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

::selection {
  background: var(--cyan);
  color: #06201a;
}

#main-content { display: block; }

/* 4. 通用工具
   ========================================================================== */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

.stack > * + * { margin-top: 1rem; }

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  letter-spacing: -0.01em;
}

/* 5. 跳过导航
   ========================================================================== */
.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 400;
  padding: 0.6rem 1rem;
  background: var(--cyan);
  color: #06201a;
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  transform: translateY(-180%);
  transition: transform 0.18s ease;
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  color: #06201a;
  outline: 2px solid var(--paper);
  outline-offset: 2px;
}

/* 6. 按钮
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.72rem 1.15rem;
  border: 1px solid transparent;
  background: var(--orange);
  color: #08150f;
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1;
  white-space: nowrap;
  cursor: pointer;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 11px), calc(100% - 11px) 100%, 0 100%);
  transition: background-color 0.18s ease, color 0.18s ease, transform 0.18s ease;
}

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

.btn:focus-visible {
  outline: none;
  box-shadow: inset 0 0 0 2px var(--cyan);
}

.btn--signal { background: var(--orange); color: #08150f; }
.btn--signal:hover { background: var(--orange-soft); color: #08150f; }

.btn--cyan { background: var(--cyan); color: #06201a; }
.btn--cyan:hover { background: var(--cyan-soft); color: #06201a; }

.btn--ghost {
  background: transparent;
  color: var(--paper);
  border-color: var(--line-strong);
}
.btn--ghost:hover {
  background: var(--cyan-wash);
  border-color: var(--cyan);
  color: var(--cyan);
}

/* 7. 框架式头部
   ========================================================================== */
.frame-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 120;
  background: var(--ink);
  box-shadow: 0 24px 48px -36px rgba(0, 0, 0, 0.95);
}

.frame-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  z-index: 3;
  background: var(--line-soft);
  pointer-events: none;
}

.frame-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--cyan) 72%, var(--orange) 100%);
  transform: scaleX(var(--read-progress, 0));
  transform-origin: left center;
  transition: transform 0.09s linear;
}

.frame-bar {
  display: grid;
  grid-template-columns: minmax(0, auto) minmax(0, 1fr) minmax(0, auto);
  align-items: center;
  gap: clamp(0.6rem, 2vw, 2rem);
  min-height: var(--bar-h);
  padding: 0.45rem var(--gutter);
  background: linear-gradient(180deg, #0a211a 0%, var(--ink) 94%);
  border-bottom: 1px solid var(--line-soft);
}

.frame-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  min-width: 0;
  color: var(--paper);
}
.frame-brand:hover { color: var(--paper); }

.frame-brand__mark {
  flex: none;
  width: 1.75rem;
  height: 1.75rem;
  background: linear-gradient(135deg, var(--cyan) 0 52%, var(--orange) 52% 100%);
  clip-path: polygon(0 0, 100% 0, 100% 62%, 62% 100%, 0 100%);
}

.frame-brand__text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.frame-brand__name {
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  line-height: 1.18;
  color: var(--paper);
  white-space: nowrap;
}

.frame-brand__tag {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.03em;
  line-height: 1.45;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.frame-status {
  display: flex;
  align-items: center;
  justify-self: center;
  gap: 0.5rem;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  white-space: nowrap;
}

.frame-status__dot {
  flex: none;
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 3px var(--orange-wash);
}

.frame-status__text { color: var(--muted); }

.frame-actions {
  display: flex;
  align-items: center;
  justify-self: end;
  gap: 0.55rem;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  min-height: 2.5rem;
  padding: 0.45rem 0.8rem;
  background: transparent;
  color: var(--paper);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  font-family: var(--font-display);
  font-size: 0.88rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: border-color 0.18s ease, color 0.18s ease;
}
.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan); }
.nav-toggle:focus-visible { outline: 2px solid var(--cyan); outline-offset: 2px; }

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 1.15rem;
  height: 2px;
  background: currentColor;
  transition: background-color 0.18s ease;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s ease, top 0.2s ease;
}
.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 0; transform: rotate(-45deg); }

.nav-toggle__label {
  font-size: 0.78rem;
  letter-spacing: 0.14em;
}

/* 8. 框架导航轨道
   ========================================================================== */
.frame-nav {
  display: flex;
  align-items: stretch;
  justify-content: space-between;
  gap: clamp(0.5rem, 2vw, 1.5rem);
  min-height: var(--nav-h);
  padding: 0 var(--gutter);
  background: var(--panel);
  border-bottom: 1px solid var(--line-strong);
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: none;
}
.frame-nav::-webkit-scrollbar { display: none; }

.frame-nav__list {
  display: flex;
  align-items: stretch;
  flex: 0 0 auto;
}

.frame-nav__item { display: flex; }

.frame-nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0 clamp(0.7rem, 1.6vw, 1.2rem);
  color: var(--muted);
  border-right: 1px solid var(--line-soft);
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  white-space: nowrap;
  transition: color 0.16s ease, background-color 0.16s ease;
}

.frame-nav__item:first-child .frame-nav__link { border-left: 1px solid var(--line-soft); }

.frame-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.22s ease;
}

.frame-nav__link:hover {
  color: var(--paper);
  background: var(--cyan-wash);
}
.frame-nav__link:hover::after { transform: scaleX(1); }

.frame-nav__link[aria-current="page"] {
  color: var(--cyan);
  background: var(--cyan-wash-strong);
}
.frame-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--orange);
}

.frame-nav__num {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--rule);
}
.frame-nav__link:hover .frame-nav__num,
.frame-nav__link[aria-current="page"] .frame-nav__num { color: var(--cyan); }

.frame-nav__meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex: 0 0 auto;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  color: var(--muted);
  white-space: nowrap;
}

.frame-nav__meta-dot {
  flex: none;
  width: 0.42rem;
  height: 0.42rem;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px var(--cyan-wash);
}

/* 9. 章节与展签
   ========================================================================== */
.section {
  position: relative;
  padding-block: clamp(2.5rem, 6vw, 5.5rem);
}

.section--tight { padding-block: clamp(1.5rem, 3vw, 2.4rem); }

.section--panel {
  background: var(--panel);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: clamp(1.5rem, 3vw, 2.25rem);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  margin: 0 0 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.71rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan);
}
.eyebrow::before {
  content: "";
  flex: none;
  width: 1.75rem;
  height: 2px;
  background: var(--cyan);
}

.chapter {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 0.5rem 1.25rem;
  margin-bottom: clamp(1.25rem, 3vw, 2rem);
}

.chapter__num {
  display: block;
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--step-chapter);
  font-weight: 800;
  line-height: 0.78;
  letter-spacing: -0.02em;
  color: transparent;
  -webkit-text-stroke: 1.5px var(--rule);
  font-variant-numeric: tabular-nums;
}

.chapter__body {
  flex: 1 1 20rem;
  min-width: 0;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--line-soft);
}

.section-title {
  margin: 0;
  font-size: var(--step-4);
  line-height: 0.98;
}
.section-title em {
  font-style: normal;
  color: var(--cyan);
}

.lede {
  max-width: 62ch;
  font-size: clamp(1.05rem, 1.6vw, 1.28rem);
  line-height: 1.68;
  color: var(--paper);
}

.prose { max-width: 68ch; }
.prose > * + * { margin-top: 1.1em; }
.prose p,
.prose li { color: var(--muted); line-height: 1.78; }
.prose strong { color: var(--paper); font-weight: 700; }
.prose h3 { margin-top: 1.9em; font-size: var(--step-2); }
.prose ul { padding-left: 1.1rem; list-style: disc; }
.prose li::marker { color: var(--cyan); }

/* 10. 网格与卡片
   ========================================================================== */
.grid {
  display: grid;
  gap: clamp(1rem, 2vw, 1.5rem);
}
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr); }

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  padding: clamp(1.1rem, 2vw, 1.5rem);
  background: var(--card);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--cyan);
  transition: transform 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}
.card:hover {
  transform: translateY(-2px);
  background: #18453a;
  border-left-color: var(--orange);
}
.card--orange { border-left-color: var(--orange); }
.card--plain { border-left-color: var(--rule); }

.card__meta {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.card__title {
  margin: 0;
  font-size: var(--step-2);
  line-height: 1.16;
}

.card__text {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--muted);
}

.panel {
  position: relative;
  padding: clamp(1.25rem, 2.4vw, 2rem);
  background: var(--panel);
  border: 1px solid var(--line);
}

.panel--cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

/* 11. 标签与数据
   ========================================================================== */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.18rem 0.55rem;
  border: 1px solid var(--line-strong);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  line-height: 1.5;
  white-space: nowrap;
}

.tag--live {
  border-color: var(--orange);
  background: var(--orange-wash);
  color: var(--orange-soft);
}

.tag--cyan {
  border-color: var(--cyan);
  background: var(--cyan-wash);
  color: var(--cyan);
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.stat__value {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.stat__label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-variant-numeric: tabular-nums;
}

.data-table th {
  padding: 0.6rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--line-strong);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan-soft);
}

.data-table td {
  padding: 0.7rem 0.75rem;
  border-bottom: 1px solid var(--line-soft);
  font-size: 0.95rem;
  color: var(--paper);
}

.data-table tbody tr { transition: background-color 0.16s ease; }
.data-table tbody tr:hover { background: var(--cyan-wash); }

.data-table .is-score {
  font-family: var(--font-mono);
  font-weight: 700;
  letter-spacing: 0.02em;
}

/* 12. 图片容器（页面阶段填充图片用）
   ========================================================================== */
.plate {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.plate--wide { aspect-ratio: 21 / 9; }
.plate--tall { aspect-ratio: 3 / 4; }
.plate--square { aspect-ratio: 1 / 1; }

.plate__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.plate__tag {
  position: absolute;
  left: 0;
  bottom: 0;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.38rem 0.7rem;
  background: rgba(7, 26, 22, 0.84);
  border-top: 1px solid var(--orange);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 0.67rem;
  letter-spacing: 0.06em;
}

.plate__tag--cyan { border-top-color: var(--cyan); color: var(--cyan-soft); }

.plate--empty {
  display: flex;
  align-items: flex-end;
  padding: 1rem;
  background:
    repeating-linear-gradient(135deg, rgba(47, 243, 208, 0.09) 0 2px, transparent 2px 14px),
    var(--panel);
  color: var(--rule);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
}

/* 13. 面包屑
   ========================================================================== */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.71rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.crumbs a {
  color: var(--muted);
  border-bottom: 1px solid transparent;
}
.crumbs a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.crumbs__sep { color: var(--rule); }

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

/* 14. 页脚
   ========================================================================== */
.site-footer {
  margin-top: clamp(3rem, 7vw, 6rem);
  background: var(--panel);
  border-top: 1px solid var(--line-strong);
  color: var(--muted);
}

.site-footer::before {
  content: "";
  display: block;
  height: 3px;
  background: repeating-linear-gradient(
    90deg,
    var(--cyan) 0 18px,
    transparent 18px 38px
  );
  opacity: 0.32;
}

.footer-frame {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr) minmax(0, 0.7fr) minmax(0, 1.15fr);
  gap: clamp(1.5rem, 3vw, 3rem);
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(2rem, 5vw, 3.75rem) var(--gutter) clamp(1.5rem, 3vw, 2.5rem);
}

.footer-brand {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3vw, 2.15rem);
  font-weight: 800;
  letter-spacing: 0.03em;
  line-height: 1.1;
  color: var(--paper);
}

.footer-line {
  margin: 0 0 0.95rem;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--muted);
}

.footer-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.28rem 0.7rem;
  border: 1px solid var(--orange);
  background: var(--orange-wash);
  color: var(--orange-soft);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
}

.footer-title {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan-soft);
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.footer-list__link {
  display: inline-block;
  color: var(--paper);
  font-size: 0.95rem;
  line-height: 1.5;
  border-bottom: 1px solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}
.footer-list__link:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.contact-list {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.contact-list__item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.45rem 0.6rem;
  padding: 0.55rem 0;
  border-bottom: 1px dashed var(--line-soft);
}

.contact-list__key {
  flex: none;
  min-width: 2.4rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  color: var(--cyan-soft);
}

.contact-list__value {
  flex: 1 1 auto;
  min-width: 0;
  color: var(--paper);
  font-size: 0.92rem;
  line-height: 1.55;
  word-break: break-word;
}

.copy-btn {
  flex: none;
  padding: 0.22rem 0.55rem;
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: color 0.16s ease, border-color 0.16s ease, background-color 0.16s ease;
}
.copy-btn:hover {
  color: var(--cyan);
  border-color: var(--cyan);
  background: var(--cyan-wash);
}
.copy-btn:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}
.copy-btn[data-copied] {
  color: #06201a;
  background: var(--cyan);
  border-color: var(--cyan);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.65rem 1.75rem;
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 1rem var(--gutter) 1.4rem;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 0.71rem;
  letter-spacing: 0.05em;
  color: var(--muted);
}

.footer-copy { margin: 0; }

.footer-note {
  flex: 1 1 100%;
  max-width: 76ch;
  margin: 0;
  font-family: var(--font-body);
  font-size: 0.8rem;
  line-height: 1.7;
  letter-spacing: 0;
  color: var(--rule);
}

/* 15. 响应式
   ========================================================================== */
@media (max-width: 1080px) {
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-frame { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 1000px) {
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--split { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 900px) {
  :root {
    --bar-h: 4.05rem;
    --frame-h: var(--bar-h);
  }

  .nav-toggle { display: inline-flex; }
  .frame-status { display: none; }

  .frame-nav {
    position: fixed;
    top: var(--frame-h);
    left: 0;
    right: 0;
    display: block;
    max-height: calc(100vh - var(--frame-h));
    overflow-y: auto;
    padding: 0.4rem var(--gutter) 1.15rem;
    border-bottom: 2px solid var(--cyan);
    background: var(--panel);
    box-shadow: 0 32px 60px -32px rgba(0, 0, 0, 0.92);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-0.5rem);
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s linear;
  }

  .frame-nav[data-open] {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
  }

  .frame-nav__list {
    flex-direction: column;
    align-items: stretch;
  }

  .frame-nav__item { width: 100%; }

  .frame-nav__link {
    width: 100%;
    min-height: 3.1rem;
    justify-content: flex-start;
    padding-inline: 0.25rem;
    border-right: 0;
    border-bottom: 1px solid var(--line-soft);
    font-size: 1.05rem;
  }

  .frame-nav__item:first-child .frame-nav__link { border-left: 0; }

  .frame-nav__link::after {
    left: 0;
    right: auto;
    width: 2.5rem;
    height: 2px;
  }

  .frame-nav__meta { margin: 0.9rem 0 0; }
}

@media (max-width: 720px) {
  .frame-brand__tag { display: none; }
  .nav-toggle__label { display: none; }
  .nav-toggle { padding: 0.45rem 0.6rem; }
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }
  .footer-frame { grid-template-columns: minmax(0, 1fr); }
  .footer-base { justify-content: flex-start; }
}

@media (max-width: 420px) {
  .frame-brand__name { font-size: 0.98rem; }
  .frame-brand__mark { width: 1.4rem; height: 1.4rem; }
  .btn--signal { padding: 0.52rem 0.7rem; font-size: 0.82rem; }
  .chapter__num { -webkit-text-stroke-width: 1px; }
}

/* 16. 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;
    scroll-behavior: auto !important;
  }

  .card:hover { transform: none; }
  .btn:hover { transform: none; }
}