/* ============================================================
   《上链》— 从 Android 工程师到 Web3 全栈开发者
   设计系统:「世界账本」— 现代银行账本 × 瑞士网格
   纯亮色 · 自包含 · 无外部字体/CDN · 无暗色模式
   ============================================================ */

:root {
  /* 纸与墨 */
  --paper:      #FAF8F2;
  --paper-deep: #F2EEE3;
  --panel:      #FFFFFF;
  --ink:        #1C211D;
  --ink-soft:   #4C544E;
  --ink-faint:  #878E86;

  /* 账本绿(贷方/收益/主色) */
  --green:      #0E6B45;
  --green-deep: #0A4F34;
  --green-tint: #E9F2EC;
  --green-line: #C2D9CB;

  /* 朱红(借方/风险/警示) */
  --red:        #B93D1C;
  --red-deep:   #93300F;
  --red-tint:   #FAEDE6;
  --red-line:   #E7C6B5;

  /* 黄铜(印章/Android 类比) */
  --brass:      #8A6C2C;
  --brass-tint: #F6EFDD;
  --brass-line: #DFCFA4;

  /* 墨蓝(代码函数名等少量点缀) */
  --blue:       #23538F;

  /* 线 */
  --line:       #D9D2C2;
  --line-soft:  #E9E3D4;

  --sans: "PingFang SC","Hiragino Sans GB","Noto Sans SC","Source Han Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --mono: ui-monospace,"SF Mono",Menlo,"JetBrains Mono","Cascadia Code","Noto Sans Mono",monospace;

  --wrap: 880px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--paper);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.95;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--green-tint); color: var(--green-deep); }

a { color: var(--green); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

/* ---------- 顶部阅读进度 ---------- */
.progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0;
  background: var(--green);
  z-index: 99;
  transition: width .1s linear;
}

/* ---------- 账页抬头(topbar) ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: rgba(250,248,242,.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.topbar-inner {
  max-width: var(--wrap); margin: 0 auto;
  padding: 12px 24px;
  display: flex; align-items: baseline; gap: 20px;
}
.brand {
  font-weight: 800; font-size: 17px; letter-spacing: .06em;
  color: var(--ink); white-space: nowrap;
}
.brand:hover { text-decoration: none; color: var(--green-deep); }
.brand .en {
  font-family: var(--mono); font-size: 10px; font-weight: 600;
  color: var(--green); letter-spacing: .22em; margin-left: 8px;
  vertical-align: 2px;
}
.topbar-links { display: flex; gap: 18px; font-size: 13px; }
.topbar-links a { color: var(--ink-soft); }
.topbar-links a:hover { color: var(--green-deep); }
.filecode {
  margin-left: auto;
  font-family: var(--mono); font-size: 11px; letter-spacing: .14em;
  color: var(--ink-faint); white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

/* ---------- 版心 ---------- */
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px 96px; }

/* ============================================================
   章节页
   ============================================================ */

/* ---------- 章头(账页记录头) ---------- */
.chapter-head { padding: 64px 0 36px; animation: rise .5s ease both; }
.chapter-meta {
  display: flex; align-items: baseline; justify-content: space-between;
  font-family: var(--mono); font-size: 11.5px; letter-spacing: .18em;
  color: var(--ink-faint); text-transform: uppercase;
}
.chapter-meta .vol { color: var(--green); font-weight: 700; }
.chapter-head h1 {
  font-size: clamp(30px, 5.4vw, 44px);
  font-weight: 800; letter-spacing: .02em; line-height: 1.35;
  margin: 14px 0 20px;
}
.chapter-head .rule { border: none; border-top: 4px double var(--ink); margin: 0 0 22px; }
.lede { font-size: 17.5px; color: var(--ink-soft); line-height: 2.05; }
.entry-tags { margin-top: 20px; display: flex; flex-wrap: wrap; gap: 8px; }
.entry-tags span {
  font-family: var(--mono); font-size: 11px; letter-spacing: .08em;
  border: 1px solid var(--line); border-radius: 2px;
  padding: 3px 9px; color: var(--ink-soft); background: var(--panel);
}

/* ---------- 正文 ---------- */
.prose { counter-reset: sec; }
.prose > * { animation: rise .5s ease both; }

.prose h2 {
  counter-increment: sec;
  font-size: 24px; font-weight: 800; letter-spacing: .02em;
  margin: 72px 0 18px; padding-top: 26px;
  border-top: 1px solid var(--line);
}
.prose h2::before {
  content: "§" counter(sec, decimal-leading-zero);
  display: block;
  font-family: var(--mono); font-size: 12px; font-weight: 600;
  letter-spacing: .2em; color: var(--green); margin-bottom: 6px;
}
.prose h3 {
  font-size: 18px; font-weight: 700; margin: 44px 0 12px;
}
.prose h3::before { content: "▸ "; color: var(--green); font-size: 14px; }
.prose p { margin: 16px 0; }
.prose ul, .prose ol { margin: 16px 0; padding-left: 26px; }
.prose li { margin: 8px 0; }
.prose li::marker { color: var(--green); font-family: var(--mono); font-size: 13px; }
.prose strong { font-weight: 700; color: var(--ink); }
.prose em { font-style: normal; color: var(--red-deep); }
.prose code {
  font-family: var(--mono); font-size: .88em;
  background: var(--paper-deep); border: 1px solid var(--line-soft);
  border-radius: 3px; padding: 1px 6px; color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.prose hr { border: none; border-top: 1px solid var(--line); margin: 48px 0; }

/* ---------- 记账体表格 ---------- */
.table-wrap { overflow-x: auto; margin: 24px 0; }
table.ledger {
  width: 100%; border-collapse: collapse;
  font-size: 14px; line-height: 1.75; background: var(--panel);
  border: 1px solid var(--line);
}
table.ledger th {
  font-family: var(--mono); font-size: 11px; font-weight: 700;
  letter-spacing: .14em; text-transform: uppercase;
  text-align: left; color: var(--ink-soft);
  padding: 10px 14px; background: var(--paper-deep);
  border-bottom: 2px solid var(--ink);
}
table.ledger td {
  padding: 10px 14px; border-bottom: 1px solid var(--line-soft);
  vertical-align: top;
}
table.ledger tr:last-child td { border-bottom: none; }
table.ledger td.num, table.ledger th.num { text-align: right; font-family: var(--mono); font-variant-numeric: tabular-nums; }
table.ledger td code { white-space: nowrap; }

/* ---------- 代码凭证(code voucher) ---------- */
.code {
  margin: 24px 0; background: var(--panel);
  border: 1px solid var(--line); border-radius: 4px;
  overflow: hidden;
}
.code-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 8px 14px;
  border-bottom: 1px dashed var(--line);
  background: var(--paper-deep);
}
.code-lang {
  font-family: var(--mono); font-size: 10.5px; font-weight: 700;
  letter-spacing: .2em; text-transform: uppercase; color: var(--brass);
}
.copy-btn {
  font-family: var(--mono); font-size: 11px; letter-spacing: .08em;
  color: var(--ink-soft); background: none;
  border: 1px solid var(--line); border-radius: 3px;
  padding: 3px 10px; cursor: pointer; transition: all .15s ease;
}
.copy-btn:hover { border-color: var(--green); color: var(--green-deep); background: var(--green-tint); }
.copy-btn.ok { border-color: var(--green); color: var(--panel); background: var(--green); }
.code pre {
  padding: 16px 18px; overflow-x: auto;
  font-family: var(--mono); font-size: 13px; line-height: 1.8;
  font-variant-numeric: tabular-nums;
}
.code pre::-webkit-scrollbar { height: 8px; }
.code pre::-webkit-scrollbar-thumb { background: var(--line); border-radius: 4px; }

/* 语法记号(手工标注) */
.k { color: var(--red-deep); font-weight: 600; }   /* 关键字 */
.t { color: var(--green-deep); font-weight: 600; } /* 类型 */
.f { color: var(--blue); }                          /* 函数/方法 */
.s { color: #9A5B00; }                              /* 字符串 */
.n { color: var(--green); }                         /* 数字/常量 */
.c { color: var(--ink-faint); font-style: italic; } /* 注释 */

/* ---------- 记账批注(callouts) ---------- */
.callout {
  margin: 26px 0; padding: 16px 20px 14px;
  border: 1px solid var(--line); border-left-width: 3px;
  border-radius: 0 4px 4px 0; background: var(--panel);
  font-size: 15px;
}
.callout .tag {
  display: inline-block;
  font-family: var(--mono); font-size: 10.5px; font-weight: 700;
  letter-spacing: .2em; text-transform: uppercase;
  margin-bottom: 8px;
}
.callout p { margin: 8px 0; }
.callout p:last-child { margin-bottom: 2px; }

.callout.credit { border-color: var(--green-line); border-left-color: var(--green); background: var(--green-tint); }
.callout.credit .tag { color: var(--green-deep); }
.callout.credit .tag::before { content: "▲ "; }

.callout.debit { border-color: var(--red-line); border-left-color: var(--red); background: var(--red-tint); }
.callout.debit .tag { color: var(--red-deep); }
.callout.debit .tag::before { content: "▼ "; }

.callout.android { border-color: var(--brass-line); border-left-color: var(--brass); background: var(--brass-tint); }
.callout.android .tag { color: var(--brass); }
.callout.android .tag::before { content: "⇄ "; }

.callout.aside { border-left-color: var(--ink-faint); background: var(--paper-deep); color: var(--ink-soft); }
.callout.aside .tag { color: var(--ink-faint); }

/* ---------- 互动演示台 ---------- */
.demo {
  margin: 32px 0; background: var(--panel);
  border: 1px solid var(--line); border-top: 3px solid var(--green);
  border-radius: 0 0 4px 4px;
}
.demo-head {
  display: flex; align-items: baseline; justify-content: space-between;
  padding: 12px 18px; border-bottom: 1px solid var(--line-soft);
}
.demo-head .title { font-weight: 700; font-size: 14.5px; }
.demo-head .badge {
  font-family: var(--mono); font-size: 10px; font-weight: 700;
  letter-spacing: .2em; color: var(--green);
}
.demo-body { padding: 18px; }
.demo-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 10px 0; }
.demo label { font-size: 13px; color: var(--ink-soft); font-weight: 600; white-space: nowrap; }
.demo input[type="text"], .demo input[type="number"], .demo textarea, .demo select {
  font-family: var(--mono); font-size: 13px;
  border: 1px solid var(--line); border-radius: 3px;
  background: var(--paper); color: var(--ink);
  padding: 7px 10px; min-width: 0; flex: 1;
}
.demo textarea { width: 100%; resize: vertical; line-height: 1.7; }
.demo input:focus, .demo textarea:focus, .demo select:focus {
  outline: 2px solid var(--green-line); border-color: var(--green);
}
.demo input[type="range"] { flex: 1; accent-color: var(--green); }
.btn {
  font-family: var(--sans); font-size: 13.5px; font-weight: 700;
  border: 1px solid var(--green-deep); border-radius: 3px;
  background: var(--green); color: #fff;
  padding: 8px 18px; cursor: pointer; letter-spacing: .04em;
  transition: all .15s ease;
}
.btn:hover { background: var(--green-deep); }
.btn:active { transform: translateY(1px); }
.btn.ghost { background: var(--panel); color: var(--green-deep); border-color: var(--green-line); }
.btn.ghost:hover { background: var(--green-tint); }
.btn.danger { background: var(--red); border-color: var(--red-deep); }
.btn.danger:hover { background: var(--red-deep); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.demo-out {
  margin-top: 12px; padding: 14px 16px;
  background: var(--paper-deep); border: 1px solid var(--line-soft); border-radius: 3px;
  font-family: var(--mono); font-size: 12.5px; line-height: 1.9;
  overflow-x: auto; white-space: pre-wrap; word-break: break-all;
  font-variant-numeric: tabular-nums;
}
.demo-out .ok { color: var(--green-deep); font-weight: 700; }
.demo-out .bad { color: var(--red-deep); font-weight: 700; }
.demo-out .dim { color: var(--ink-faint); }
.demo-note { margin-top: 10px; font-size: 12.5px; color: var(--ink-faint); }

/* 挖矿链条演示的块 */
.chain-row { display: flex; gap: 10px; overflow-x: auto; padding: 6px 2px 10px; }
.blockcard {
  min-width: 190px; flex: 1;
  border: 1px solid var(--green-line); border-radius: 4px;
  background: var(--green-tint); padding: 10px 12px;
  font-family: var(--mono); font-size: 11px; line-height: 1.8;
  transition: all .2s ease;
}
.blockcard.broken { border-color: var(--red); background: var(--red-tint); }
.blockcard .bt { font-weight: 700; letter-spacing: .1em; font-size: 10px; color: var(--green-deep); }
.blockcard.broken .bt { color: var(--red-deep); }
.blockcard .hash { word-break: break-all; color: var(--ink-soft); }
.blockcard input {
  width: 100%; font-family: var(--mono); font-size: 11px;
  border: 1px solid var(--line); border-radius: 2px;
  padding: 3px 6px; margin: 4px 0; background: #fff;
}

/* mini-EVM 面板 */
.evm-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 14px; }
.evm-panel {
  border: 1px solid var(--line-soft); border-radius: 3px; background: var(--paper);
  padding: 10px 12px; font-family: var(--mono); font-size: 12px; line-height: 1.9;
}
.evm-panel .pt {
  font-size: 10px; font-weight: 700; letter-spacing: .18em;
  color: var(--ink-faint); text-transform: uppercase;
  border-bottom: 1px solid var(--line-soft); padding-bottom: 4px; margin-bottom: 6px;
}
.evm-op { padding: 1px 6px; border-radius: 2px; }
.evm-op.cur { background: var(--green); color: #fff; font-weight: 700; }
.stack-cell {
  border: 1px solid var(--green-line); background: var(--green-tint);
  border-radius: 2px; padding: 2px 8px; margin: 3px 0;
  word-break: break-all;
}

/* ---------- 章间导航(过账) ---------- */
.chapter-nav {
  margin-top: 88px; border-top: 4px double var(--ink);
  padding-top: 22px;
  display: grid; grid-template-columns: 1fr 1fr; gap: 14px;
}
.chapter-nav a {
  border: 1px solid var(--line); border-radius: 4px;
  background: var(--panel); padding: 14px 18px;
  color: var(--ink); transition: all .15s ease;
  display: block;
}
.chapter-nav a:hover {
  text-decoration: none; border-color: var(--green);
  background: var(--green-tint); transform: translateY(-2px);
}
.chapter-nav .dir {
  font-family: var(--mono); font-size: 10.5px; font-weight: 700;
  letter-spacing: .18em; color: var(--green); text-transform: uppercase;
  display: block; margin-bottom: 4px;
}
.chapter-nav .t { font-size: 14.5px; font-weight: 700; color: var(--ink); }
.chapter-nav a.next { text-align: right; }
.chapter-nav a.placeholder {
  visibility: hidden;
}
.backline { text-align: center; margin-top: 18px; }
.backline a {
  font-family: var(--mono); font-size: 12px; letter-spacing: .14em;
  color: var(--ink-faint);
}
.backline a:hover { color: var(--green-deep); }

/* ---------- 页脚(封账线) ---------- */
.site-foot {
  margin-top: 64px; padding-top: 18px;
  border-top: 4px double var(--ink);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px;
  font-family: var(--mono); font-size: 11px; letter-spacing: .12em;
  color: var(--ink-faint);
}
.site-foot .seal { color: var(--green); font-weight: 700; }

/* ============================================================
   总览页(index)
   ============================================================ */
.hero {
  padding: 84px 0 48px;
  background-image: repeating-linear-gradient(
    to bottom, transparent 0 38px, rgba(28,33,29,.045) 38px 39px);
}
.hero-meta-top {
  display: flex; justify-content: space-between; align-items: baseline;
  font-family: var(--mono); font-size: 11.5px; letter-spacing: .2em;
  color: var(--ink-faint); text-transform: uppercase;
  animation: rise .5s ease both;
}
.hero-meta-top .l { color: var(--green); font-weight: 700; }
.hero h1 {
  font-size: clamp(64px, 13vw, 124px);
  font-weight: 900; letter-spacing: .08em; line-height: 1.15;
  margin: 24px 0 6px;
  animation: rise .6s ease .05s both;
}
.hero h1 .cursor {
  display: inline-block; width: .09em; height: .82em;
  background: var(--green); margin-left: .06em;
  animation: blink 1.1s steps(1) infinite;
  vertical-align: -0.04em;
}
.hero .sub {
  font-size: clamp(16px, 2.6vw, 20px); font-weight: 600;
  color: var(--ink-soft); letter-spacing: .12em;
  animation: rise .6s ease .12s both;
}
.hero .desc {
  margin-top: 26px; max-width: 620px;
  font-size: 15.5px; color: var(--ink-soft);
  animation: rise .6s ease .2s both;
}
.stamp {
  float: right; margin: 8px 0 0 20px;
  transform: rotate(6deg);
  border: 2.5px solid var(--green); border-radius: 4px;
  color: var(--green); font-family: var(--mono);
  font-size: 12px; font-weight: 700; letter-spacing: .3em;
  padding: 8px 14px; text-transform: uppercase;
  opacity: .85;
  animation: stamp .45s cubic-bezier(.2,2.2,.4,1) .5s both;
}
.hero-ledgerline {
  margin-top: 40px; border: none; border-top: 4px double var(--ink);
  animation: rise .6s ease .25s both;
}
.hero-stats {
  display: flex; flex-wrap: wrap; gap: 0;
  border: 1px solid var(--line); border-top: none; background: var(--panel);
  animation: rise .6s ease .3s both;
}
.hero-stats .cell {
  flex: 1; min-width: 130px; padding: 14px 18px;
  border-right: 1px solid var(--line-soft);
}
.hero-stats .cell:last-child { border-right: none; }
.hero-stats .v {
  font-family: var(--mono); font-size: 22px; font-weight: 700;
  color: var(--green-deep); font-variant-numeric: tabular-nums;
}
.hero-stats .k {
  font-family: var(--mono); font-size: 10px; font-weight: 600; color: var(--ink-faint);
  letter-spacing: .18em; text-transform: uppercase;
}

/* 卷(volume) */
.vol { margin-top: 72px; animation: rise .5s ease both; }
.vol-head { display: flex; align-items: baseline; gap: 16px; margin-bottom: 6px; }
.vol-head .vno {
  font-family: var(--mono); font-size: 13px; font-weight: 700;
  letter-spacing: .22em; color: var(--green);
}
.vol-head h2 { font-size: 23px; font-weight: 800; letter-spacing: .03em; }
.vol-head .vdesc { font-size: 13.5px; color: var(--ink-faint); margin-left: auto; text-align: right; }
.vol-list { border: 1px solid var(--line); border-top: 2px solid var(--ink); background: var(--panel); }
.entry {
  display: grid; grid-template-columns: 64px 1fr auto 34px;
  gap: 14px; align-items: baseline;
  padding: 15px 18px; color: var(--ink);
  border-bottom: 1px solid var(--line-soft);
  transition: background .15s ease;
}
.entry:last-child { border-bottom: none; }
.entry:hover { background: var(--green-tint); text-decoration: none; }
.entry .no {
  font-family: var(--mono); font-size: 15px; font-weight: 700;
  color: var(--ink-faint); font-variant-numeric: tabular-nums; letter-spacing: .04em;
}
.entry:hover .no { color: var(--green-deep); }
.entry .et { font-weight: 700; font-size: 15.5px; }
.entry .ed { display: block; font-size: 13px; color: var(--ink-faint); font-weight: 400; margin-top: 2px; }
.entry .demo-tag {
  font-family: var(--mono); font-size: 10px; font-weight: 700;
  letter-spacing: .14em; color: var(--green-deep);
  border: 1px solid var(--green-line); background: var(--green-tint);
  border-radius: 2px; padding: 2px 8px; white-space: nowrap;
  align-self: center;
}
.entry .arr {
  font-family: var(--mono); color: var(--ink-faint);
  transition: transform .15s ease; align-self: center; text-align: right;
}
.entry:hover .arr { color: var(--green-deep); transform: translateX(4px); }

/* ---------- 动画 ---------- */
@keyframes rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
@keyframes blink { 0%,55% { opacity: 1; } 56%,100% { opacity: 0; } }
@keyframes stamp { from { opacity: 0; transform: rotate(6deg) scale(1.6); } to { opacity: .85; transform: rotate(6deg) scale(1); } }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 720px) {
  body { font-size: 15.5px; }
  .topbar-inner { padding: 11px 16px; gap: 12px; }
  .topbar-links { gap: 12px; font-size: 12px; }
  .wrap { padding: 0 16px 72px; }
  .chapter-head { padding: 44px 0 28px; }
  .chapter-nav { grid-template-columns: 1fr; }
  .chapter-nav a.next { text-align: left; }
  .chapter-nav a.placeholder { display: none; }
  .entry { grid-template-columns: 44px 1fr; }
  .entry .demo-tag, .entry .arr { display: none; }
  .vol-head { flex-wrap: wrap; }
  .vol-head .vdesc { margin-left: 0; text-align: left; width: 100%; }
  .evm-grid { grid-template-columns: 1fr; }
  .stamp { float: none; display: inline-block; margin: 16px 0 0; }
  .hero { padding: 56px 0 36px; }
}