/* 比特浏览器 实测笔记 —— 米白纸感文档风
 * 暖米纸底 / 墨色正文 / 竹青墨绿点缀 / 圆角软影 / 宽松行距
 * 区别于 faq 版蓝白企业风、faq2 版橙黑硬核风 */
:root {
  --paper: #f5f1e6;
  --paper2: #fdfaf2;
  --card: #fffdf7;
  --ink: #2e2b25;
  --ink2: #57524a;
  --ink3: #8d8578;
  --line: #e4dcc9;
  --line2: #d3c9b0;
  --grn: #3f6b58;
  --grn2: #56856f;
  --grn-dim: rgba(63, 107, 88, .10);
  --brn: #a4642f;
  --red: #b04040;
  --maxw: 900px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  background: var(--paper);
  background-image:
    radial-gradient(rgba(120, 105, 75, .05) 1px, transparent 1px),
    linear-gradient(180deg, #f7f3e9 0%, var(--paper) 100%);
  background-size: 22px 22px, 100% 100%;
  color: var(--ink2);
  font-family: "PingFang SC", "Microsoft YaHei", HarmonyOS_Sans_SC, -apple-system, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  line-height: 1.85;
  font-size: 16px;
}
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
img, svg { max-width: 100%; display: block; }
code, kbd, pre { font-family: "Cascadia Code", Consolas, "SF Mono", Menlo, monospace; }
::selection { background: var(--grn); color: #fffdf7; }

/* ===== 顶栏：纸面 + 细线 ===== */
.hd {
  position: sticky; top: 0; z-index: 20;
  background: rgba(245, 241, 230, .92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line2);
}
.hd-in {
  max-width: var(--maxw); margin: 0 auto; padding: 0 20px;
  height: 62px; display: flex; align-items: center; gap: 14px;
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); }
.brand svg { width: 26px; height: 26px; flex: none; }
.brand .brand-logo { height: 26px; width: auto; display: block; }
.brand b { font-size: 18px; font-weight: 700; letter-spacing: 0; }
.brand b em { color: var(--grn); font-style: normal; }
.brand span {
  font-size: 11px; color: var(--grn); font-weight: 600; letter-spacing: 2px;
  padding: 3px 9px; background: var(--grn-dim); border: 1px solid rgba(63,107,88,.35);
  border-radius: 99px;
}
.hd .sp { flex: 1; }
.hd-back {
  font-size: 13px; font-weight: 600; color: #fffdf7; background: var(--grn);
  padding: 8px 17px; border-radius: 99px; white-space: nowrap;
  box-shadow: 0 2px 6px rgba(63,107,88,.25);
  transition: background .15s, transform .15s;
}
.hd-back:hover { background: var(--grn2); transform: translateY(-1px); }

/* ===== 容器 / 大标题 ===== */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.hero { padding: 56px 0 30px; border-bottom: 1px dashed var(--line2); }
.hero .kick {
  display: inline-block; font-size: 12px; font-weight: 600; letter-spacing: 3px;
  color: var(--brn); margin-bottom: 14px;
}
.hero .kick::before { content: "✎ "; }
.hero h1 {
  font-size: 38px; line-height: 1.25; letter-spacing: 0; color: var(--ink); font-weight: 700;
}
.hero h1 em { color: var(--grn); font-style: normal; }
.hero p { margin-top: 16px; color: var(--ink2); font-size: 15.5px; max-width: 66ch; }
.hero .meta { margin-top: 22px; display: flex; gap: 10px 28px; flex-wrap: wrap; font-size: 13px; color: var(--ink3); }
.hero .meta b { color: var(--grn); font-weight: 700; font-size: 15px; }

/* ===== 搜索 + 分类 ===== */
.tools { padding: 24px 0; border-bottom: 1px dashed var(--line2); }
.search {
  width: 100%; background: var(--card); border: 1px solid var(--line2);
  color: var(--ink); font-size: 15px; padding: 14px 18px; border-radius: 10px;
  font-family: inherit; outline: none;
  box-shadow: 0 1px 3px rgba(90, 78, 55, .06);
  transition: border-color .15s, box-shadow .15s;
}
.search:focus { border-color: var(--grn); box-shadow: 0 0 0 3px var(--grn-dim); }
.search::placeholder { color: var(--ink3); }
.cats { margin-top: 14px; display: flex; gap: 8px; flex-wrap: wrap; }
.cat {
  font-size: 13px; font-weight: 500; color: var(--ink2); background: var(--card);
  border: 1px solid var(--line2); border-radius: 99px;
  padding: 6px 15px; cursor: pointer; user-select: none;
  transition: all .15s; font-family: inherit;
}
.cat:hover { color: var(--grn); border-color: var(--grn2); }
.cat.on { background: var(--grn); border-color: var(--grn); color: #fffdf7; }
.cat i { font-style: normal; opacity: .55; margin-left: 5px; font-size: 11px; }

/* ===== 列表：纸卡片 + 软影 ===== */
.list { padding: 24px 0 32px; display: flex; flex-direction: column; gap: 12px; }
.qa {
  background: var(--card); border: 1px solid var(--line);
  border-radius: 10px; padding: 17px 20px;
  box-shadow: 0 1px 4px rgba(90, 78, 55, .05);
  transition: border-color .15s, box-shadow .15s, transform .12s;
}
.qa:hover { border-color: var(--grn2); box-shadow: 0 4px 14px rgba(90, 78, 55, .10); transform: translateY(-1px); }
a.qa-q {
  display: block; font-size: 16px; font-weight: 600; line-height: 1.6; color: var(--ink);
}
a.qa-q:hover { color: var(--grn); }
.qa-tag {
  display: inline-block; font-size: 10.5px; font-weight: 600; letter-spacing: 1px;
  color: var(--grn); background: var(--grn-dim); border-radius: 99px;
  padding: 2px 9px; margin-right: 9px; vertical-align: 2px;
}
.qa-sum { margin-top: 10px; color: var(--ink2); font-size: 14.5px; max-width: 74ch; }
.qa-info { margin-top: 11px; font-size: 12px; color: var(--ink3); display: flex; gap: 18px; flex-wrap: wrap; }
.qa-foot { margin-top: 12px; display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.qa-more {
  font-size: 12.5px; font-weight: 600; color: var(--grn);
  border-bottom: 1px dashed rgba(63, 107, 88, .5); padding-bottom: 1px;
}
.qa-more:hover { border-bottom-color: var(--grn); border-bottom-style: solid; }
.qa-len { font-size: 11.5px; color: var(--ink3); }
.empty { padding: 54px 0; text-align: center; color: var(--ink3); font-size: 15px; }
.empty[hidden] { display: none; }

/* ===== 分页 ===== */
.pager { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; padding: 6px 0 64px; justify-content: center; }
.pg {
  min-width: 35px; height: 35px; padding: 0 11px; border: 1px solid var(--line2);
  background: var(--card); color: var(--ink2); border-radius: 8px; cursor: pointer;
  font-family: inherit; font-size: 13px; font-weight: 500; transition: all .13s;
}
.pg:hover:not(:disabled):not(.on) { border-color: var(--grn); color: var(--grn); }
.pg.on { background: var(--grn); border-color: var(--grn); color: #fffdf7; }
.pg:disabled { opacity: .35; cursor: not-allowed; }
.pg-dot { color: var(--ink3); padding: 0 2px; }
.pg-info { margin-left: 10px; font-size: 12px; color: var(--ink3); }

/* ===== 文章页 ===== */
.crumb { padding: 26px 0 0; font-size: 12.5px; color: var(--ink3); display: flex; gap: 8px; flex-wrap: wrap; }
.crumb a:hover { color: var(--grn); }
.crumb i { font-style: normal; opacity: .5; }
.art { padding: 18px 0 24px; border-bottom: 1px dashed var(--line2); }
.art h1 { font-size: 28px; line-height: 1.35; letter-spacing: 0; color: var(--ink); font-weight: 700; }
.art-meta { margin-top: 16px; font-size: 12.5px; color: var(--ink3); display: flex; gap: 22px; flex-wrap: wrap; }
.art-lead {
  margin: 24px 0 8px; padding: 17px 20px;
  background: var(--grn-dim); border: 1px solid rgba(63,107,88,.22); border-radius: 10px;
  color: var(--ink2); font-size: 14.5px;
}
.art-lead b { color: var(--grn); font-weight: 700; display: block; margin-bottom: 7px; font-size: 12px; letter-spacing: 2px; }
.art-lead a { color: var(--grn); font-weight: 600; border-bottom: 1px dashed rgba(63,107,88,.5); }

.toc { margin: 24px 0 8px; padding: 16px 20px; background: var(--card); border: 1px solid var(--line); border-radius: 10px; box-shadow: 0 1px 4px rgba(90,78,55,.05); }
.toc b { display: block; font-size: 11.5px; color: var(--brn); letter-spacing: 2px; margin-bottom: 10px; font-weight: 700; }
.toc ol { counter-reset: t; }
.toc li { counter-increment: t; font-size: 13.5px; padding: 3px 0 3px 26px; position: relative; }
.toc li::before { content: counter(t, decimal-leading-zero); position: absolute; left: 0; top: 4px; font-size: 11px; color: var(--grn); font-family: Consolas, monospace; }
.toc a { color: var(--ink2); }
.toc a:hover { color: var(--grn); }

.doc { padding: 12px 0 30px; }
.doc > * { max-width: 76ch; }
.doc h2 {
  font-size: 20px; margin: 40px 0 14px; color: var(--ink); font-weight: 700; letter-spacing: 0;
  padding-bottom: 6px; border-bottom: 2px solid var(--grn); display: inline-block; line-height: 1.4; scroll-margin-top: 78px;
}
.doc h3 { font-size: 16.5px; margin: 26px 0 10px; color: var(--ink); font-weight: 600; }
.doc p { margin: 15px 0; color: var(--ink2); }
.doc strong { color: var(--ink); font-weight: 700; }
.doc em { color: var(--brn); font-style: normal; }
.doc a { color: var(--grn); border-bottom: 1px dashed rgba(63, 107, 88, .4); }
.doc a:hover { border-bottom-color: var(--grn); border-bottom-style: solid; }
.doc code { background: #efe9da; color: var(--brn); font-size: .87em; padding: 2px 7px; border-radius: 4px; }
.doc kbd {
  background: var(--card); border: 1px solid var(--line2); border-bottom-width: 2px;
  color: var(--ink); font-size: .82em; padding: 2px 8px; border-radius: 5px; white-space: nowrap;
}
.doc ul { margin: 15px 0; }
.doc ul li { position: relative; padding-left: 19px; margin: 9px 0; color: var(--ink2); }
.doc ul li::before { content: ""; position: absolute; left: 2px; top: 13px; width: 6px; height: 6px; border-radius: 50%; background: var(--grn); }
.doc ol.steps { margin: 18px 0; counter-reset: s; }
.doc ol.steps > li { counter-increment: s; position: relative; padding-left: 38px; margin: 14px 0; color: var(--ink2); }
.doc ol.steps > li::before {
  content: counter(s); position: absolute; left: 0; top: 2px;
  width: 25px; height: 25px; border-radius: 50%;
  background: var(--grn); color: #fffdf7; font-size: 12.5px; font-weight: 700;
  display: flex; align-items: center; justify-content: center; font-family: Consolas, monospace;
}
.doc figure { margin: 28px 0; }
.doc figure img, .doc figure svg {
  border-radius: 10px; border: 1px solid var(--line); background: var(--card);
  box-shadow: 0 2px 10px rgba(90, 78, 55, .08);
  margin: 0 auto; width: 100%; height: auto;
}
.doc figcaption { margin-top: 11px; font-size: 12px; color: var(--ink3); text-align: center; line-height: 1.7; }
.doc blockquote {
  margin: 22px 0; padding: 15px 19px; background: var(--card);
  border-left: 3px solid var(--line2); border-radius: 0 10px 10px 0;
  color: var(--ink2); font-size: 14px; white-space: pre-line;
}
.doc pre {
  margin: 20px 0; padding: 16px 18px; background: #2e2b25;
  border-radius: 10px;
  overflow-x: auto; font-size: 12.5px; line-height: 1.75; color: #e8e2d4;
}
.doc pre code { background: none; color: inherit; padding: 0; }
.doc .note {
  margin: 26px 0; padding: 15px 19px; background: var(--grn-dim);
  border: 1px solid rgba(63, 107, 88, .25); border-radius: 10px;
  font-size: 14px; color: var(--ink2);
}
.doc .note b { color: var(--grn); font-weight: 700; }
.doc .warn {
  margin: 26px 0; padding: 15px 19px; background: rgba(176, 64, 64, .06);
  border: 1px solid rgba(176, 64, 64, .25); border-radius: 10px;
  font-size: 14px; color: var(--ink2);
}
.doc .warn b { color: var(--red); font-weight: 700; }

.doc .tw { margin: 22px 0; overflow-x: auto; }
.doc table { border-collapse: collapse; width: 100%; font-size: 13.5px; min-width: 460px; background: var(--card); }
.doc th, .doc td { border: 1px solid var(--line); padding: 10px 13px; text-align: left; vertical-align: top; line-height: 1.65; }
.doc th { background: #efe9da; font-weight: 700; color: var(--ink); white-space: nowrap; }
.doc td { color: var(--ink2); }
.doc tbody tr:nth-child(even) td { background: rgba(63, 107, 88, .03); }

.rel { border-top: 1px dashed var(--line2); padding: 26px 0 0; }
.rel b { display: block; font-size: 11.5px; color: var(--brn); letter-spacing: 2px; margin-bottom: 12px; font-weight: 700; }
.rel ul { display: flex; flex-direction: column; gap: 2px; }
.rel a { display: block; padding: 9px 0 9px 16px; font-size: 14px; color: var(--ink2); position: relative; }
.rel a::before { content: ""; position: absolute; left: 0; top: 18px; width: 5px; height: 5px; border-radius: 50%; background: var(--grn); }
.rel a:hover { color: var(--grn); }

.art-nav { border-top: 1px dashed var(--line2); margin-top: 26px; padding: 26px 0 64px; display: flex; gap: 12px; flex-wrap: wrap; }
.art-nav a {
  flex: 1 1 46%; min-width: 240px; background: var(--card);
  border: 1px solid var(--line); border-radius: 10px; padding: 15px 18px;
  box-shadow: 0 1px 4px rgba(90,78,55,.05);
  transition: border-color .15s, box-shadow .15s;
}
.art-nav a:hover { border-color: var(--grn2); box-shadow: 0 4px 14px rgba(90,78,55,.10); }
.art-nav .k { font-size: 11px; color: var(--brn); letter-spacing: 2px; font-weight: 700; }
.art-nav .v { margin-top: 6px; font-size: 14px; color: var(--ink); line-height: 1.55; }
.art-nav .home { flex-basis: 100%; text-align: center; }

/* ===== 页脚 ===== */
.ft { background: #ede7d8; border-top: 1px solid var(--line2); margin-top: 12px; }
.ft-in { max-width: var(--maxw); margin: 0 auto; padding: 32px 20px 46px; }
.ft p { font-size: 12px; color: var(--ink3); line-height: 1.9; max-width: 80ch; }
.ft p + p { margin-top: 9px; }
.ft a { color: var(--ink2); border-bottom: 1px dashed var(--line2); }
.ft a:hover { color: var(--grn); }

@media (max-width: 640px) {
  body { font-size: 15.5px; }
  .hero { padding: 36px 0 22px; }
  .hero h1 { font-size: 26px; }
  .art h1 { font-size: 22px; }
  .doc h2 { font-size: 18px; margin: 32px 0 12px; }
  .qa { padding: 14px 16px; }
  a.qa-q { font-size: 15.5px; }
  .qa-tag { display: none; }
  .art-nav a { flex-basis: 100%; }
  .pg-info { width: 100%; text-align: center; margin: 6px 0 0; }
}
@media print { .hd, .tools, .art-nav, .toc, .pager { display: none; } body { background: #fff; color: #000; } }