/* ==========================================================================
   AI 发展史 · 站点样式表
   无外部依赖，纯 CSS。设计系统 + 组件 + 响应式。
   ========================================================================== */

/* ---------- 1. 设计令牌 ---------- */
:root {
  --bg: #070a12;
  --bg-soft: #0b1020;
  --panel: #101728;
  --panel-2: #141d33;
  --line: #22304d;
  --line-soft: #1a2540;

  --text: #e8eefb;
  --text-dim: #a7b6d0;
  --text-mute: #6f7f9d;

  --cyan: #35e0ff;
  --violet: #8b7bff;
  --amber: #ffb454;
  --rose: #ff6b8b;
  --green: #4ade9b;

  --grad: linear-gradient(100deg, var(--cyan), var(--violet) 55%, var(--amber));
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 18px 50px -22px rgba(0, 0, 0, .85);
  --maxw: 1160px;

  --font: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Noto Sans SC",
          "Source Han Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", "Cascadia Code", Consolas, "SF Mono", Menlo, monospace;
}

/* ---------- 2. 基础 ---------- */
* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16.5px;
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(900px 520px at 12% -8%, rgba(53, 224, 255, .10), transparent 65%),
    radial-gradient(760px 460px at 88% 4%, rgba(139, 123, 255, .11), transparent 62%),
    radial-gradient(680px 420px at 50% 108%, rgba(255, 180, 84, .06), transparent 65%);
}

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

a { color: var(--cyan); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 { line-height: 1.3; margin: 0 0 .5em; font-weight: 700; letter-spacing: .2px; }
p { margin: 0 0 1em; }
ul, ol { margin: 0 0 1em; padding-left: 1.25em; }
li { margin: .3em 0; }
strong { color: #fff; font-weight: 700; }
code, .mono { font-family: var(--mono); font-size: .88em; }

.wrap { width: min(100% - 2.6rem, var(--maxw)); margin-inline: auto; position: relative; z-index: 1; }
.center { text-align: center; }
.muted { color: var(--text-dim); }
.small { font-size: .86rem; }
.nowrap { white-space: nowrap; }

::selection { background: rgba(53, 224, 255, .28); }

/* 滚动条 */
::-webkit-scrollbar { width: 11px; height: 11px; }
::-webkit-scrollbar-track { background: #0a0f1b; }
::-webkit-scrollbar-thumb { background: #253352; border-radius: 8px; border: 2px solid #0a0f1b; }
::-webkit-scrollbar-thumb:hover { background: #33456c; }

/* ---------- 3. 顶部导航 ---------- */
.progress {
  position: fixed; top: 0; left: 0; height: 2px; width: 0%;
  background: var(--grad); z-index: 120; transition: width .1s linear;
}

.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(7, 10, 18, .72);
  border-bottom: 1px solid transparent;
  transition: border-color .25s, background .25s;
}
.nav.scrolled { border-bottom-color: var(--line-soft); background: rgba(7, 10, 18, .9); }

.nav-in {
  width: min(100% - 2.6rem, var(--maxw)); margin-inline: auto;
  display: flex; align-items: center; gap: 1.4rem; height: 66px;
}

.brand { display: flex; align-items: center; gap: .6rem; font-weight: 800; letter-spacing: .5px; color: var(--text); }
.brand:hover { text-decoration: none; }
.brand-mark {
  width: 30px; height: 30px; border-radius: 9px; flex: none;
  background: var(--grad);
  display: grid; place-items: center;
  font-size: 15px; color: #06101f; font-weight: 900;
  box-shadow: 0 0 22px -4px rgba(53, 224, 255, .55);
}
.brand small { display: block; font-size: .66rem; color: var(--text-mute); font-weight: 500; letter-spacing: 1.4px; }

.nav-links { display: flex; gap: .3rem; margin-left: auto; align-items: center; }
.nav-links a {
  color: var(--text-dim); padding: .42rem .8rem; border-radius: 8px;
  font-size: .93rem; font-weight: 600; transition: .2s;
}
.nav-links a:hover { color: #fff; background: rgba(255, 255, 255, .06); text-decoration: none; }
.nav-links a.active { color: #06101f; background: var(--cyan); }

.burger {
  display: none; margin-left: auto; width: 42px; height: 38px; border-radius: 10px;
  border: 1px solid var(--line); background: rgba(255, 255, 255, .04);
  cursor: pointer; padding: 0; place-items: center;
}
.burger span { display: block; width: 18px; height: 2px; background: var(--text); margin: 3px auto; border-radius: 2px; transition: .25s; }
.burger.open span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.burger.open span:nth-child(2) { opacity: 0; }
.burger.open span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

/* ---------- 4. 通用区块 ---------- */
.section { padding: 84px 0; position: relative; }
.section.tight { padding: 56px 0; }
.section + .section { border-top: 1px solid var(--line-soft); }

.kicker {
  display: inline-flex; align-items: center; gap: .55rem;
  font-family: var(--mono); font-size: .74rem; letter-spacing: 2.4px;
  text-transform: uppercase; color: var(--cyan);
  padding: .3rem .7rem; border: 1px solid rgba(53, 224, 255, .3);
  border-radius: 999px; background: rgba(53, 224, 255, .07); margin-bottom: 1rem;
}
.kicker::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 10px var(--cyan); }

h2.h-sec { font-size: clamp(1.5rem, 3.4vw, 2.15rem); margin-bottom: .5rem; }
.lead { color: var(--text-dim); max-width: 74ch; margin-bottom: 2.2rem; }
.sec-head { margin-bottom: 2.4rem; }

.grid { display: grid; gap: 1.1rem; }
.g2 { grid-template-columns: repeat(2, 1fr); }
.g3 { grid-template-columns: repeat(3, 1fr); }
.g4 { grid-template-columns: repeat(4, 1fr); }

/* ---------- 5. 卡片 ---------- */
.card {
  background: linear-gradient(180deg, var(--panel), var(--bg-soft));
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 1.4rem 1.4rem 1.2rem;
  position: relative;
  transition: transform .3s cubic-bezier(.2,.7,.3,1), border-color .3s, box-shadow .3s;
}
.card:hover { transform: translateY(-4px); border-color: rgba(53, 224, 255, .38); box-shadow: var(--shadow); }
.card h3 { font-size: 1.08rem; margin-bottom: .45rem; }
.card p { color: var(--text-dim); font-size: .94rem; margin-bottom: .5rem; }
.card p:last-child { margin-bottom: 0; }
.card .idx {
  font-family: var(--mono); font-size: .74rem; color: var(--text-mute);
  letter-spacing: 2px; display: block; margin-bottom: .5rem;
}

.card-accent::after {
  content: ""; position: absolute; left: 1.4rem; right: 1.4rem; top: 0; height: 2px;
  background: var(--grad); border-radius: 2px; opacity: .85;
}

/* 阶段总览 */
.era {
  display: grid; grid-template-columns: 92px 1fr; gap: 1.1rem;
  align-items: start; padding: 1.15rem 1.3rem;
  border: 1px solid var(--line-soft); border-radius: var(--radius);
  background: linear-gradient(120deg, rgba(20, 29, 51, .9), rgba(11, 16, 32, .75));
  transition: .28s;
}
.era:hover { border-color: rgba(139, 123, 255, .45); transform: translateX(4px); }
.era .span {
  font-family: var(--mono); font-size: .8rem; font-weight: 700;
  color: var(--cyan); padding-top: .2rem; letter-spacing: .5px;
}
.era h3 { font-size: 1.05rem; margin-bottom: .3rem; }
.era p { margin: 0; color: var(--text-dim); font-size: .92rem; }
.era .tagline { font-size: .78rem; color: var(--amber); font-family: var(--mono); letter-spacing: 1px; }

/* ---------- 6. Hero ---------- */
.hero { padding: 150px 0 92px; position: relative; }
.hero h1 {
  font-size: clamp(2.1rem, 6vw, 4rem); line-height: 1.14; letter-spacing: -.5px;
  margin-bottom: 1.1rem;
}
.hero h1 .grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero .sub { font-size: clamp(1rem, 1.9vw, 1.16rem); color: var(--text-dim); max-width: 66ch; margin-bottom: 1.9rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-bottom: 3rem; }

.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .68rem 1.3rem; border-radius: 999px; font-weight: 700; font-size: .95rem;
  border: 1px solid var(--line); color: var(--text); background: rgba(255, 255, 255, .04);
  transition: .22s; cursor: pointer; text-decoration: none;
}
.btn:hover { transform: translateY(-2px); border-color: var(--cyan); color: #fff; text-decoration: none; }
.btn-primary { background: var(--grad); color: #06101f; border-color: transparent; box-shadow: 0 12px 34px -14px rgba(53, 224, 255, .8); }
.btn-primary:hover { color: #06101f; }

.stat-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.stat {
  border-left: 2px solid var(--cyan); padding: .1rem 0 .1rem 1rem;
}
.stat b { display: block; font-family: var(--mono); font-size: clamp(1.35rem, 3.2vw, 2rem); color: #fff; line-height: 1.2; }
.stat > span { font-size: .84rem; color: var(--text-mute); }

/* Hero 装饰网格 */
.hero-deco {
  position: absolute; right: 0; top: 96px; width: 380px; height: 380px;
  border-radius: 50%; opacity: .5; pointer-events: none; z-index: 0;
  background:
    radial-gradient(circle, rgba(53, 224, 255, .18), transparent 62%);
  filter: blur(6px);
}

/* ---------- 7. 算力柱状图 ---------- */
.chart { display: grid; gap: .7rem; margin-top: 1.4rem; }
.bar-row { display: grid; grid-template-columns: 200px 1fr 78px; gap: .9rem; align-items: center; }
.bar-label { font-size: .88rem; color: var(--text-dim); }
.bar-label b { color: var(--text); display: block; font-size: .92rem; }
.bar-track { height: 26px; background: rgba(255, 255, 255, .045); border-radius: 7px; overflow: hidden; }
.bar-fill {
  height: 100%; width: 0; border-radius: 7px;
  background: linear-gradient(90deg, rgba(53, 224, 255, .85), rgba(139, 123, 255, .85));
  transition: width 1.1s cubic-bezier(.2,.8,.2,1);
  box-shadow: 0 0 20px -4px rgba(53, 224, 255, .6);
}
.bar-val { font-family: var(--mono); font-size: .82rem; color: var(--cyan); text-align: right; }

/* ---------- 8. 表格 ---------- */
.table-scroll { overflow-x: auto; border: 1px solid var(--line-soft); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; font-size: .92rem; min-width: 640px; }
th, td { padding: .85rem 1rem; text-align: left; border-bottom: 1px solid var(--line-soft); vertical-align: top; }
th { background: rgba(255, 255, 255, .035); color: #fff; font-size: .84rem; letter-spacing: .6px; font-weight: 700; }
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover { background: rgba(53, 224, 255, .035); }
td.mono, th.mono { font-family: var(--mono); font-size: .84rem; color: var(--text-dim); }

/* ---------- 9. 时间轴 ---------- */
.filters {
  display: flex; flex-wrap: wrap; gap: .5rem; align-items: center;
  margin-bottom: 1.6rem; position: sticky; top: 66px; z-index: 40;
  padding: .85rem 0; background: linear-gradient(180deg, var(--bg) 62%, rgba(7, 10, 18, 0));
}
.chip {
  border: 1px solid var(--line); background: rgba(255, 255, 255, .035);
  color: var(--text-dim); border-radius: 999px; padding: .38rem .95rem;
  font-size: .86rem; font-weight: 600; cursor: pointer; transition: .2s; font-family: var(--font);
}
.chip:hover { color: #fff; border-color: var(--text-mute); }
.chip.on { background: var(--cyan); color: #06101f; border-color: transparent; }
.chip[data-cat="winter"].on { background: var(--rose); color: #fff; }
.chip[data-cat="china"].on { background: var(--amber); color: #21160a; }

.search {
  margin-left: auto; position: relative;
}
.search input {
  width: 220px; padding: .42rem .9rem .42rem 2rem;
  background: rgba(255, 255, 255, .04); border: 1px solid var(--line);
  border-radius: 999px; color: var(--text); font-family: var(--font); font-size: .88rem;
  outline: none; transition: .2s;
}
.search input:focus { border-color: var(--cyan); width: 260px; }
.search::before {
  content: "⌕"; position: absolute; left: .72rem; top: 50%; transform: translateY(-52%);
  color: var(--text-mute); font-size: 1rem; pointer-events: none;
}

.tl { list-style: none; margin: 0; padding: 0; position: relative; }
.tl::before {
  content: ""; position: absolute; left: 50%; top: 6px; bottom: 6px; width: 2px;
  transform: translateX(-1px);
  background: linear-gradient(180deg, transparent, var(--line) 4%, var(--line) 96%, transparent);
}
.tl-item {
  position: relative; width: calc(50% - 34px); margin: 0 0 1rem;
  opacity: 0; transform: translateY(22px);
  transition: opacity .5s, transform .5s;
}
.tl-item.in { opacity: 1; transform: none; }
.tl-item.r { margin-left: calc(50% + 34px); }

.tl-item::after {
  content: ""; position: absolute; top: 26px; width: 14px; height: 14px;
  border-radius: 50%; background: var(--bg); border: 2px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(53, 224, 255, .12);
}
.tl-item::after { right: -42px; }
.tl-item.r::after { right: auto; left: -42px; }
.tl-item[data-cat="winter"]::after { border-color: var(--rose); box-shadow: 0 0 0 4px rgba(255, 107, 139, .14); }
.tl-item[data-cat="china"]::after { border-color: var(--amber); box-shadow: 0 0 0 4px rgba(255, 180, 84, .14); }
.tl-item[data-cat="now"]::after { border-color: var(--green); box-shadow: 0 0 0 4px rgba(74, 222, 155, .14); }

.tl-body {
  background: linear-gradient(180deg, var(--panel), var(--bg-soft));
  border: 1px solid var(--line-soft); border-radius: var(--radius);
  padding: 1.05rem 1.2rem; transition: .25s;
}
.tl-item:hover .tl-body { border-color: rgba(53, 224, 255, .4); box-shadow: var(--shadow); }
.tl-year {
  font-family: var(--mono); font-size: .82rem; font-weight: 700; color: var(--cyan);
  letter-spacing: 1px;
}
.tl-item[data-cat="winter"] .tl-year { color: var(--rose); }
.tl-item[data-cat="china"] .tl-year { color: var(--amber); }
.tl-body h3 { font-size: 1.02rem; margin: .18rem 0 .4rem; }
.tl-body p { font-size: .92rem; color: var(--text-dim); margin-bottom: 0; }
.tl-body details { margin-top: .6rem; border-top: 1px dashed var(--line-soft); padding-top: .5rem; }
.tl-body summary {
  cursor: pointer; font-size: .84rem; color: var(--cyan); font-weight: 600;
  list-style: none; display: inline-flex; align-items: center; gap: .35rem;
}
.tl-body summary::-webkit-details-marker { display: none; }
.tl-body summary::after { content: "▾"; transition: .2s; font-size: .7rem; }
.tl-body details[open] summary::after { transform: rotate(180deg); }
.tl-body details p { margin-top: .5rem; font-size: .89rem; }
.tl-tags { display: flex; flex-wrap: wrap; gap: .35rem; margin-top: .55rem; }
.tl-tags span {
  font-family: var(--mono); font-size: .7rem; letter-spacing: .5px;
  padding: .1rem .5rem; border-radius: 5px;
  background: rgba(53, 224, 255, .1); color: var(--cyan); border: 1px solid rgba(53, 224, 255, .18);
}
.tl-tags span.k { background: rgba(139, 123, 255, .12); color: var(--violet); border-color: rgba(139, 123, 255, .22); }
.tl-tags span.w { background: rgba(255, 107, 139, .12); color: var(--rose); border-color: rgba(255, 107, 139, .22); }
.tl-tags span.c { background: rgba(255, 180, 84, .12); color: var(--amber); border-color: rgba(255, 180, 84, .22); }

.tl-empty { display: none; text-align: center; padding: 3rem 0; color: var(--text-mute); }
.tl-empty.show { display: block; }

/* ---------- 10. 人物卡 ---------- */
.person { display: flex; flex-direction: column; }
.person .top { display: flex; align-items: center; gap: .85rem; margin-bottom: .8rem; }
.avatar {
  width: 46px; height: 46px; flex: none; border-radius: 12px;
  display: grid; place-items: center; font-weight: 800; font-size: 1.05rem;
  color: #06101f; background: var(--grad); font-family: var(--mono);
}
.avatar.v2 { background: linear-gradient(135deg, var(--amber), var(--rose)); }
.avatar.v3 { background: linear-gradient(135deg, var(--green), var(--cyan)); }
.person h3 { margin: 0; font-size: 1rem; }
.person .who { font-size: .78rem; color: var(--text-mute); font-family: var(--mono); }
.person p { font-size: .9rem; }
.person .keys { margin-top: auto; padding-top: .6rem; border-top: 1px dashed var(--line-soft); font-size: .82rem; color: var(--text-mute); }
.person .keys b { color: var(--cyan); font-weight: 600; }

/* 引用 */
.quote {
  border-left: 3px solid var(--violet); padding: .2rem 0 .2rem 1.1rem;
  color: var(--text-dim); font-style: italic; margin: 1.2rem 0;
}
.quote cite { display: block; font-style: normal; font-size: .82rem; color: var(--text-mute); margin-top: .35rem; }

/* 提示块 */
.note {
  background: rgba(53, 224, 255, .05); border: 1px solid rgba(53, 224, 255, .2);
  border-radius: var(--radius-sm); padding: .95rem 1.1rem; font-size: .91rem;
  color: var(--text-dim); margin: 1.3rem 0;
}
.note.warn { background: rgba(255, 180, 84, .06); border-color: rgba(255, 180, 84, .24); }
.note b { color: #fff; }

/* ---------- 11. 页脚 / 返回顶部 ---------- */
.footer {
  border-top: 1px solid var(--line-soft); padding: 40px 0 56px;
  color: var(--text-mute); font-size: .87rem; background: rgba(4, 6, 12, .5);
}
.footer-in { display: flex; flex-wrap: wrap; gap: 1rem 2rem; justify-content: space-between; align-items: start; }
.footer a { color: var(--text-dim); }
.footer-nav { display: flex; flex-wrap: wrap; gap: .4rem 1.2rem; }

.totop {
  position: fixed; right: 22px; bottom: 22px; z-index: 90;
  width: 44px; height: 44px; border-radius: 12px; cursor: pointer;
  border: 1px solid var(--line); background: rgba(16, 23, 40, .9);
  color: var(--text); font-size: 1.1rem; display: grid; place-items: center;
  opacity: 0; pointer-events: none; transition: .28s; backdrop-filter: blur(10px);
}
.totop.show { opacity: 1; pointer-events: auto; }
.totop:hover { border-color: var(--cyan); transform: translateY(-3px); }

/* ---------- 12. 动效 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s cubic-bezier(.2,.7,.3,1), transform .7s cubic-bezier(.2,.7,.3,1); }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition-duration: .01ms !important; }
  .reveal, .tl-item { opacity: 1 !important; transform: none !important; }
}

/* ---------- 13. 响应式 ---------- */
@media (max-width: 1000px) {
  .g4 { grid-template-columns: repeat(2, 1fr); }
  .g3 { grid-template-columns: repeat(2, 1fr); }
  .stat-row { grid-template-columns: repeat(2, 1fr); gap: 1.3rem; }
  .hero-deco { display: none; }
}

@media (max-width: 820px) {
  body { font-size: 16px; }
  .nav-links {
    position: fixed; inset: 66px 0 auto; flex-direction: column; align-items: stretch;
    background: rgba(7, 10, 18, .98); border-bottom: 1px solid var(--line);
    padding: .6rem 1.3rem 1.2rem; gap: .2rem; margin-left: 0;
    transform: translateY(-130%); transition: transform .3s; backdrop-filter: blur(14px);
  }
  .nav-links.open { transform: none; }
  .nav-links a { padding: .7rem .4rem; border-bottom: 1px solid var(--line-soft); border-radius: 0; }
  .nav-links a.active { background: none; color: var(--cyan); }
  .burger { display: grid; }

  .hero { padding: 118px 0 66px; }
  /* 窄屏下按 6vw 计算最小仍是 2.1rem，主标题第二行「到会推理的万亿参数模型」会折出孤字。
     这里用更小的下限 + 更高的 vw 系数，保证 11 个字（含标点）能在一行内排下；
     在 320px 的 iPhone SE 上同样验证过可容纳。 */
  .hero h1 { font-size: clamp(1.6rem, 7.2vw, 2.6rem); }
  /* 英文 kicker 在窄屏折成两行会让胶囊形状很别扭，收紧字距与字号 */
  .kicker { font-size: .66rem; letter-spacing: 1.4px; }
  .section { padding: 60px 0; }
  .g2, .g3, .g4 { grid-template-columns: 1fr; }
  .era { grid-template-columns: 1fr; gap: .3rem; }
  .era .span { padding-top: 0; }

  /* 时间轴改为单侧 */
  .tl::before { left: 7px; }
  .tl-item, .tl-item.r { width: 100%; margin-left: 0; padding-left: 34px; }
  .tl-item::after, .tl-item.r::after { left: 0; right: auto; top: 22px; }
  .filters { top: 66px; }
  .search { margin-left: 0; width: 100%; }
  .search input, .search input:focus { width: 100%; }
  .bar-row { grid-template-columns: 1fr; gap: .2rem; }
  .bar-val { text-align: left; }
  .bar-label b { display: inline; }
}

@media print {
  .nav, .totop, .progress, .filters, .hero-actions { display: none !important; }
  body { background: #fff; color: #111; }
  body::before { display: none; }
  .card, .tl-body, .era, .table-scroll { border-color: #ccc; background: #fff; box-shadow: none; }
  .tl::before { background: #ccc; }
  .reveal, .tl-item { opacity: 1 !important; transform: none !important; }
}

/* ---------- 14. 无障碍：跳转链接与键盘焦点 ---------- */
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 300;
  background: var(--cyan); color: #06101f;
  padding: .7rem 1.1rem; font-weight: 700; border-radius: 0 0 10px 0;
}
.skip-link:focus { left: 0; text-decoration: none; }

/* 深色背景下浏览器默认焦点环极易不可见，这里强制一个高对比焦点样式。
   使用 :focus-visible 而非 :focus，鼠标点击不会留下难看的轮廓。 */
:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 2px;
  border-radius: 4px;
}
.btn:focus-visible, .chip:focus-visible, .totop:focus-visible, .burger:focus-visible { outline-offset: 3px; }
.nav-links a:focus-visible { outline-offset: 0; }
.tl-body summary:focus-visible { outline-offset: 4px; }
.deploy-warn a, .deploy-warn code:focus-visible { outline-offset: 1px; }

/* ---------- 15. 部署自检提示条 ---------- */
/* 当页面里的域名仍是占位符 ai-history.example 时，由 main.js 注入本提示条。
   替换为真实域名后该提示会自动消失，无需改动代码。 */
.deploy-warn {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 250;
  background: #3a1420; color: #ffd9e2;
  border-top: 2px solid var(--rose);
  padding: .75rem 1rem; font-size: .88rem; line-height: 1.65; text-align: center;
}
.deploy-warn code {
  background: rgba(255, 255, 255, .12); padding: .08rem .4rem;
  border-radius: 4px; font-family: var(--mono); font-size: .85em;
}
body.has-deploy-warn .totop { bottom: 84px; }