/* ==========================================================================
   Home of 17.  —  Minimalist Monochrome
   纯黑白、零圆角、零阴影，靠线、字与留白建立秩序。
   ========================================================================== */

/* ---------- 1. 设计令牌 ---------- */
:root {
  /* 颜色：只有黑与白，灰只用于次要文字与细线 */
  --bg: #ffffff;
  --fg: #000000;
  --muted-bg: #f5f5f5;
  --muted-fg: #525252;
  --border: #000000;
  --border-light: #e5e5e5;
  --card: #ffffff;
  --invert-bg: #000000;
  --invert-fg: #ffffff;

  /* 字体 */
  --font-display: "Playfair Display", "Songti SC", "Source Han Serif SC", "Noto Serif SC", STSong, SimSun, Georgia, serif;
  --font-body: "Source Serif 4", Georgia, "Songti SC", "Source Han Serif SC", "Noto Serif SC", SimSun, serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Consolas, "Courier New", monospace;

  /* 尺寸与节奏 */
  --header-h: 60px;
  --nav-w: 246px;
  --toc-w: 220px;
  --grid-max: 1280px;
  --gap: 40px;
  --pad-x: 32px;
}

html[data-theme="dark"] {
  --bg: #000000;
  --fg: #ffffff;
  --muted-bg: #111111;
  --muted-fg: #a3a3a3;
  --border: #ffffff;
  --border-light: #2a2a2a;
  --card: #000000;
  --invert-bg: #ffffff;
  --invert-fg: #000000;
}

/* ---------- 2. 基础 ---------- */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  padding-top: var(--header-h);
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-wrap: break-word;
}

/* 纸张质感：极淡的横纹 + 噪点，避免扁平 */
body::after {
  content: "";
  position: fixed; inset: 0; z-index: 999; pointer-events: none;
  background-image:
    repeating-linear-gradient(0deg, transparent, transparent 1px, var(--fg) 1px, var(--fg) 2px);
  background-size: 100% 4px;
  opacity: .015;
}
body::before {
  content: "";
  position: fixed; inset: 0; z-index: 998; pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  opacity: .022;
}

a { color: var(--fg); text-decoration: none; border-bottom: 1px solid var(--border-light); }
a:hover { border-bottom-color: var(--fg); }
p { margin: 0 0 1.1em; }
ul, ol { margin: 0 0 1.1em; padding-left: 1.4em; }
li { margin: .35em 0; }
li::marker { color: var(--fg); }
hr { border: 0; border-top: 1px solid var(--border); margin: 2.5rem 0; }
strong { font-weight: 700; }

code {
  font-family: var(--font-mono); font-size: .84em;
  background: var(--muted-bg); padding: .08em .4em;
  border: 1px solid var(--border-light);
}

.muted { color: var(--muted-fg); }
.tiny { font-size: .78rem; }
.small { font-size: .88rem; }
.center { text-align: center; }
.hidden { display: none !important; }
[hidden] { display: none !important; }
::selection { background: var(--fg); color: var(--bg); }

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

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 400;
  background: var(--invert-bg); color: var(--invert-fg);
  padding: 10px 16px; font-family: var(--font-mono); font-size: .8rem;
}
.skip-link:focus { left: 0; }

/* ---------- 3. 顶栏 ---------- */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 120;
  height: var(--header-h);
  background: var(--bg);
  border-bottom: 2px solid var(--border);
}
.header__inner {
  max-width: var(--grid-max); height: 100%; margin: 0 auto; padding: 0 var(--pad-x);
  display: flex; align-items: center; gap: 18px;
}
.home__cta { display: flex; flex-wrap: wrap; gap: 14px; margin: 0 0 1rem; }
.brand { display: flex; align-items: baseline; gap: 12px; border: 0; min-width: 0; }
.brand:hover { border: 0; }
.brand__mark {
  font-family: var(--font-display); font-size: 1.3rem; font-weight: 700;
  letter-spacing: -.02em; white-space: nowrap;
}
.brand__sub {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .16em;
  text-transform: uppercase; color: var(--muted-fg); white-space: nowrap;
}

.icon-btn {
  width: 40px; height: 40px; flex: 0 0 auto; display: none; place-items: center;
  background: transparent; border: 1px solid transparent; cursor: pointer; color: var(--fg);
}
.icon-btn:hover { border-color: var(--border); }
.bars, .bars::before, .bars::after {
  display: block; width: 18px; height: 2px; background: var(--fg); position: relative;
}
.bars::before, .bars::after { content: ""; position: absolute; left: 0; }
.bars::before { top: -6px; }
.bars::after { top: 6px; }

.text-btn {
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .18em;
  text-transform: uppercase; padding: 8px 14px; cursor: pointer;
  background: transparent; color: var(--fg); border: 2px solid var(--border);
  transition: background-color .1s linear, color .1s linear;
}
.text-btn:hover { background: var(--invert-bg); color: var(--invert-fg); }

/* 搜索 */
.md-search { position: relative; margin-left: auto; width: 220px; }
.md-search input {
  width: 100%; height: 36px; padding: 0 34px 0 0;
  border: 0; border-bottom: 2px solid var(--border);
  background: transparent; color: var(--fg);
  font-family: var(--font-body); font-size: .92rem;
}
.md-search input::placeholder { color: var(--muted-fg); }
.md-search input:focus { outline: none; border-bottom-width: 4px; }
.md-search__kbd {
  position: absolute; right: 0; top: 50%; transform: translateY(-50%);
  font-family: var(--font-mono); font-size: .7rem; color: var(--muted-fg);
  border: 1px solid var(--border-light); padding: 1px 6px;
}
.md-search__output {
  position: absolute; top: calc(100% + 12px); right: 0; left: auto;
  width: min(620px, calc(100vw - 32px));
  background: var(--bg); border: 2px solid var(--border); z-index: 200;
}
.md-search__scroll { max-height: min(64vh, 520px); overflow-y: auto; padding: 6px; }
.md-search__hint { padding: 16px 12px; color: var(--muted-fg); font-size: .86rem; margin: 0; }
.md-search__group {
  font-family: var(--font-mono); font-size: .66rem; letter-spacing: .18em;
  text-transform: uppercase; color: var(--muted-fg);
  padding: 12px 12px 6px; border-bottom: 1px solid var(--border-light);
}
.md-search__hit { display: block; padding: 10px 12px; border: 0; border-bottom: 1px solid var(--border-light); }
.md-search__hit:last-child { border-bottom: 0; }
.md-search__hit:hover, .md-search__hit.on { background: var(--invert-bg); color: var(--invert-fg); }
.md-search__hit:hover .h-path, .md-search__hit.on .h-path,
.md-search__hit:hover .h-snip, .md-search__hit.on .h-snip { color: var(--invert-fg); opacity: .75; }
.md-search__hit .h-title { font-weight: 700; font-size: .92rem; }
.md-search__hit .h-path {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--muted-fg); margin-top: 2px;
}
.md-search__hit .h-snip {
  font-size: .84rem; color: var(--muted-fg); margin-top: 4px; line-height: 1.55;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.md-search__hit mark { background: var(--fg); color: var(--bg); padding: 0 2px; }

/* ---------- 4. 布局 ---------- */
.md-container {
  max-width: var(--grid-max); margin: 0 auto; padding: 0 var(--pad-x);
  display: grid; grid-template-columns: var(--nav-w) minmax(0, 1fr) var(--toc-w);
  gap: var(--gap); align-items: start;
}
.md-sidebar { position: sticky; top: var(--header-h); height: calc(100vh - var(--header-h)); }
.md-sidebar--primary { overflow: hidden; border-right: 1px solid var(--border-light); }
.md-sidebar--primary .md-sidebar__scroll {
  height: 100%; overflow-y: auto; overscroll-behavior: contain;
  padding: 32px 24px 48px 0;
}
.md-sidebar--secondary { overflow-y: auto; overscroll-behavior: contain; padding: 32px 0 48px 4px; }
.md-sidebar::-webkit-scrollbar, .md-sidebar__scroll::-webkit-scrollbar { width: 6px; }
.md-sidebar::-webkit-scrollbar-thumb, .md-sidebar__scroll::-webkit-scrollbar-thumb { background: var(--border-light); }

.md-main { min-width: 0; padding: 56px 0 96px; }
.md-main:focus { outline: none; }

.md-scrim { position: fixed; inset: 0; z-index: 110; background: rgba(0, 0, 0, .5); }

/* ---------- 5. 左侧导航 ---------- */
.md-nav { font-size: .92rem; }
.md-nav__list { list-style: none; margin: 0; padding: 0; }
.md-nav__item { margin: 0; }
.md-nav__link {
  display: block; padding: 6px 10px; border: 0;
  color: var(--fg); line-height: 1.5; transition: background-color .1s linear, color .1s linear;
}
.md-nav__link:hover { background: var(--muted-bg); border: 0; }
.md-nav__link--active { background: var(--invert-bg); color: var(--invert-fg); font-weight: 700; }
.md-nav__toggle {
  width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 8px;
  padding: 8px 10px; cursor: pointer; background: transparent; color: var(--fg);
  border: 0; border-top: 1px solid var(--border-light);
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .12em;
  text-transform: uppercase; text-align: left;
}
.md-nav__item:first-child > .md-nav__toggle { border-top: 0; }
.md-nav__toggle:hover { background: var(--muted-bg); }
.md-nav__toggle .chev { font-family: var(--font-mono); font-size: .95rem; line-height: 1; }
.md-nav__list--nested { display: none; padding-left: 12px; border-left: 1px solid var(--border-light); margin-left: 10px; }
.md-nav__item--open > .md-nav__list--nested { display: block; }
.md-nav__item--subsection > .md-nav__toggle { border-top: 0; color: var(--muted-fg); }
.md-nav__item--section > .md-nav__toggle { letter-spacing: .14em; }

/* ---------- 6. 右侧目录 ---------- */
.md-toc__title {
  font-family: var(--font-mono); font-size: .66rem; letter-spacing: .18em;
  text-transform: uppercase; color: var(--muted-fg); margin: 0 0 12px;
}
.md-toc__list { list-style: none; margin: 0; padding: 0; }
.md-toc__list li { margin: 0; }
.md-toc__list a {
  display: block; padding: 5px 0 5px 12px; border: 0; border-left: 2px solid transparent;
  font-size: .84rem; line-height: 1.5; color: var(--muted-fg);
}
.md-toc__list a:hover { color: var(--fg); border-left-color: var(--border-light); }
.md-toc__list a.on { color: var(--fg); border-left-color: var(--fg); font-weight: 700; }
.md-toc__back {
  display: block; margin-top: 18px; padding-top: 12px;
  border: 0; border-top: 1px solid var(--border-light);
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .14em;
  text-transform: uppercase; color: var(--muted-fg);
}
.md-toc__back:hover { color: var(--fg); }

/* ---------- 7. 正文排版 ---------- */
.md-breadcrumbs {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--muted-fg); margin-bottom: 22px;
}
.md-breadcrumbs a { border: 0; color: var(--muted-fg); }
.md-breadcrumbs a:hover { color: var(--fg); }
.md-breadcrumbs .sep { opacity: .45; }

.md-content { font-size: 1.02rem; line-height: 1.8; }

.kicker {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .22em;
  text-transform: uppercase; color: var(--muted-fg); margin: 0 0 18px;
}
.md-content h1 {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(2rem, 4.6vw, 3.4rem); line-height: 1.12;
  letter-spacing: -.025em; margin: 0 0 .5em;
}
.md-content h2 {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(1.35rem, 2.4vw, 1.75rem); line-height: 1.25;
  letter-spacing: -.02em; margin: 3rem 0 .8rem; padding-top: 1.2rem;
  border-top: 4px solid var(--border);
}
.md-content h3 {
  font-family: var(--font-body); font-weight: 700; font-size: 1.12rem;
  margin: 2rem 0 .6rem;
}
.md-content h1:first-child, .md-content h2:first-child { margin-top: 0; }
.md-content h2, .md-content h3 { scroll-margin-top: calc(var(--header-h) + 24px); }
.headerlink {
  background: none; border: 0; cursor: pointer; padding: 0 0 0 .5rem;
  font-family: var(--font-mono); font-size: .6em; color: var(--muted-fg);
  opacity: 0; transition: opacity .1s linear;
}
.md-content h2:hover .headerlink, .md-content h3:hover .headerlink { opacity: 1; }
.headerlink:hover { color: var(--fg); }

.display {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(3.2rem, 13vw, 9rem); line-height: .92;
  letter-spacing: -.05em; margin: 0 0 .35em;
}
.lead-xl {
  font-size: 1.2rem; line-height: 1.65; color: var(--fg);
  max-width: 46rem; margin-bottom: 1.2em;
}
.md-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 24px; }
.chip {
  font-family: var(--font-mono); font-size: .66rem; letter-spacing: .1em;
  text-transform: uppercase; padding: 3px 9px;
  border: 1px solid var(--border-light); color: var(--muted-fg);
}
.chip-brand { border-color: var(--border); color: var(--fg); }

.md-actions {
  display: flex; flex-wrap: wrap; gap: 12px; align-items: center;
  margin-top: 3rem; padding-top: 1.4rem; border-top: 1px solid var(--border);
}

/* 署名与联系方式 */
.signoff {
  margin-top: 3rem; padding-top: 1.2rem; border-top: 4px solid var(--border);
}
.signoff__mark {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .2em;
  text-transform: uppercase; color: var(--muted-fg); margin: 0 0 6px;
}
.signoff__text { font-size: .92rem; margin: 0; color: var(--muted-fg); }

/* 横线 */
.rule { border: 0; border-top: 1px solid var(--border); margin: 3rem 0; }
.rule--heavy { border-top: 8px solid var(--border); margin: 3.5rem 0; }

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .16em;
  text-transform: uppercase; padding: 12px 20px; cursor: pointer;
  background: transparent; color: var(--fg); border: 2px solid var(--border);
  transition: background-color .1s linear, color .1s linear;
}
.btn:hover { background: var(--invert-bg); color: var(--invert-fg); border-color: var(--border); }
.btn-primary { background: var(--invert-bg); color: var(--invert-fg); border-color: var(--invert-bg); }
.btn-primary:hover { background: transparent; color: var(--fg); border-color: var(--border); }
.btn-outline { background: transparent; color: var(--fg); border-color: var(--border); }
.btn-outline:hover { background: var(--invert-bg); color: var(--invert-fg); }
.btn-ghost { border-color: transparent; padding-left: 0; padding-right: 0; }
.btn-ghost:hover { background: transparent; color: var(--fg); border-bottom: 2px solid var(--fg); }
.btn-danger { border-color: var(--border); color: var(--muted-fg); }
.btn-danger:hover { background: transparent; color: var(--fg); }
.btn-sm { padding: 8px 14px; font-size: .68rem; }
.btn-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }

/* ---------- 9. 提示块 ---------- */
.admonition {
  margin: 1.6em 0; padding: 18px 22px;
  border: 1px solid var(--border); border-left: 8px solid var(--border);
  background: var(--bg);
}
.admonition .admonition-title {
  font-family: var(--font-mono); font-size: .7rem; letter-spacing: .16em;
  text-transform: uppercase; margin: 0 0 10px; color: var(--fg);
}
.admonition p:last-child, .admonition ul:last-child, .admonition ol:last-child { margin-bottom: 0; }
/* 核心观点：整块反白 */
.admonition--idea {
  background: var(--invert-bg); color: var(--invert-fg);
  border-color: var(--invert-bg); border-left-width: 8px;
  padding: 26px 28px;
}
.admonition--idea .admonition-title { color: var(--invert-fg); opacity: .7; }
.admonition--idea strong { color: var(--invert-fg); }
.admonition--idea a { color: var(--invert-fg); border-bottom-color: var(--invert-fg); }

/* 引用 */
.quote {
  margin: 1.8em 0; padding: 0 0 0 22px;
  border-left: 4px solid var(--border);
  font-family: var(--font-display); font-size: 1.14rem;
}
.quote cite {
  display: block; margin-top: 10px; font-family: var(--font-mono); font-style: normal;
  font-size: .68rem; letter-spacing: .12em; text-transform: uppercase; color: var(--muted-fg);
}

/* 大号拉引 */
.pullquote {
  margin: 4rem 0; padding: 2.5rem 0;
  border-top: 4px solid var(--border); border-bottom: 4px solid var(--border);
  position: relative;
}
.pullquote::before {
  content: "\201C"; position: absolute; top: -1.2rem; left: -6px;
  font-family: var(--font-display); font-size: 6rem; line-height: 1;
  color: var(--fg); opacity: .16;
}
.pullquote p {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3.4vw, 2.1rem); line-height: 1.35;
  letter-spacing: -.02em; margin: 0; position: relative;
}
.pullquote cite {
  display: block; margin-top: 14px; font-family: var(--font-mono); font-style: normal;
  font-size: .68rem; letter-spacing: .14em; text-transform: uppercase; color: var(--muted-fg);
}

/* 表格 */
.table-wrap { overflow-x: auto; margin: 1.6em 0; }
table { width: 100%; border-collapse: collapse; font-size: .94rem; }
th, td { padding: 11px 14px; text-align: left; border-bottom: 1px solid var(--border-light); vertical-align: top; }
th {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .12em;
  text-transform: uppercase; font-weight: 500;
  border-bottom: 2px solid var(--border); white-space: nowrap;
}
tbody tr:hover { background: var(--muted-bg); }

/* 步骤 */
.steps { counter-reset: step; margin: 1.6em 0; display: grid; gap: 0; }
.step {
  position: relative; padding: 16px 20px 16px 58px;
  border-top: 1px solid var(--border-light);
}
.step:first-child { border-top: 2px solid var(--border); }
.step:last-child { border-bottom: 1px solid var(--border-light); }
.step::before {
  counter-increment: step; content: counter(step, decimal-leading-zero);
  position: absolute; left: 0; top: 16px;
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .1em; color: var(--muted-fg);
}
.step b { display: block; font-size: .98rem; }
.step p { margin: 4px 0 0; font-size: .92rem; color: var(--muted-fg); }

/* 键值 */
.kv-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 0; margin: 1.6em 0; }
.kv { border: 1px solid var(--border-light); padding: 14px 16px; margin: -1px 0 0 -1px; }
.kv dt { font-weight: 700; font-size: .94rem; margin-bottom: 4px; }
.kv dd { margin: 0; font-size: .9rem; color: var(--muted-fg); }

/* 可勾选清单 */
.checklist { margin: 1.6em 0; border: 1px solid var(--border); padding: 18px 22px; }
.checklist-head {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  margin-bottom: 10px; padding-bottom: 10px; border-bottom: 2px solid var(--border);
}
.checklist-head b { font-size: .96rem; }
.checklist label { display: flex; gap: 12px; align-items: flex-start; padding: 5px 0; cursor: pointer; font-size: .95rem; }
.checklist input {
  appearance: none; width: 16px; height: 16px; flex: 0 0 auto; margin-top: .35em;
  border: 2px solid var(--border); background: transparent; cursor: pointer; position: relative;
}
.checklist input:checked { background: var(--invert-bg); }
.checklist input:checked::after {
  content: ""; position: absolute; left: 3px; top: -1px; width: 4px; height: 9px;
  border-right: 2px solid var(--invert-fg); border-bottom: 2px solid var(--invert-fg);
  transform: rotate(40deg);
}
.checklist input:checked + span { color: var(--muted-fg); text-decoration: line-through; }

/* 网格卡片（悬停整块反白） */
.md-cards { display: grid; gap: 0; margin: 1.6em 0; grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr)); }
.md-card {
  display: block; border: 1px solid var(--border); margin: -1px 0 0 -1px;
  padding: 22px 24px; color: var(--fg); background: var(--bg);
  transition: background-color .1s linear, color .1s linear;
}
.md-card:hover { background: var(--invert-bg); color: var(--invert-fg); border-color: var(--border); }
.md-card__num {
  display: block; font-family: var(--font-display); font-size: 1.6rem;
  line-height: 1; margin-bottom: 12px;
}
.md-card__title { font-weight: 700; font-size: 1rem; line-height: 1.45; }
.md-card__desc { font-size: .9rem; color: var(--muted-fg); margin: 6px 0 0; line-height: 1.65; }
.md-card:hover .md-card__desc { color: var(--invert-fg); opacity: .8; }
.md-card__meta { margin-top: 12px; display: flex; flex-wrap: wrap; gap: 6px; }
.md-card:hover .chip { border-color: var(--invert-fg); color: var(--invert-fg); opacity: .8; }

/* 首页：四个思想 */
.idea-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0; margin: 0 0 1rem; }
.idea-card {
  display: block; border: 1px solid var(--border); margin: -1px 0 0 -1px;
  padding: 38px 34px 34px; color: var(--fg); background: var(--bg);
  transition: background-color .1s linear, color .1s linear;
}
.idea-card:hover { background: var(--invert-bg); color: var(--invert-fg); border-color: var(--border); }
.idea-card__num {
  font-family: var(--font-display); font-size: 2.6rem; line-height: 1;
  display: block; margin-bottom: 20px; letter-spacing: -.03em;
}
.idea-card__title {
  font-family: var(--font-display); font-size: 1.5rem; font-weight: 700;
  line-height: 1.2; letter-spacing: -.02em; margin: 0 0 12px; border: 0; padding: 0;
}
.idea-card__text { font-size: .95rem; color: var(--muted-fg); margin: 0 0 18px; line-height: 1.7; }
.idea-card:hover .idea-card__text { color: var(--invert-fg); opacity: .82; }
.idea-card__more {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .16em;
  text-transform: uppercase; border-bottom: 1px solid currentColor; padding-bottom: 2px;
}

/* 首页：章节列表 */
.chapter-list { list-style: none; margin: 1.6em 0; padding: 0; }
.chapter-list li { margin: 0; }
.chapter-list a {
  display: flex; align-items: baseline; gap: 22px;
  padding: 20px 0; border: 0; border-top: 1px solid var(--border-light);
}
.chapter-list li:last-child a { border-bottom: 1px solid var(--border-light); }
.chapter-list a:hover { background: var(--muted-bg); padding-left: 12px; padding-right: 12px; }
.chapter-list__num {
  font-family: var(--font-display); font-size: 1.9rem; line-height: 1;
  min-width: 2.2rem; letter-spacing: -.03em;
}
.chapter-list__body { flex: 1; display: flex; flex-direction: column; }
.chapter-list__title { font-size: 1.1rem; font-weight: 700; }
.chapter-list__sub { font-size: .9rem; color: var(--muted-fg); }
.chapter-list__meta {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .14em;
  text-transform: uppercase; color: var(--muted-fg);
}

/* 上下页 */
.md-prevnext {
  display: grid; grid-template-columns: 1fr 1fr; gap: 0;
  margin-top: 4rem; border-top: 4px solid var(--border);
}
.md-prevnext a {
  display: block; padding: 22px 24px; border: 0; color: var(--fg);
  transition: background-color .1s linear, color .1s linear;
}
.md-prevnext a:hover { background: var(--invert-bg); color: var(--invert-fg); }
.md-prevnext .dir {
  display: block; font-family: var(--font-mono); font-size: .66rem; letter-spacing: .16em;
  text-transform: uppercase; color: var(--muted-fg); margin-bottom: 6px;
}
.md-prevnext a:hover .dir { color: var(--invert-fg); opacity: .75; }
.md-prevnext .ttl { font-family: var(--font-display); font-size: 1.1rem; font-weight: 700; line-height: 1.3; }
.md-prevnext .prev { text-align: left; grid-column: 1; border-right: 1px solid var(--border-light); }
.md-prevnext .next { text-align: right; grid-column: 2; }
.md-prevnext .spacer { display: block; grid-column: 1; }

/* ---------- 10. 工具与表单 ---------- */
.tool-card { border: 1px solid var(--border); padding: 26px 28px; margin: 0 0 28px; }
.tool-card h3 {
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .16em;
  text-transform: uppercase; font-weight: 500; margin: 0 0 16px;
  padding-bottom: 10px; border-bottom: 1px solid var(--border-light);
}
.tool-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 14px; flex-wrap: wrap; }
.tool-note {
  font-family: var(--font-mono); font-size: .7rem; letter-spacing: .08em;
  color: var(--muted-fg); margin-bottom: 20px;
}
.tool-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 24px; }

.field { margin-bottom: 18px; }
.field label {
  display: block; font-family: var(--font-mono); font-size: .68rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--muted-fg); margin-bottom: 8px;
}
input[type="text"], input[type="number"], input[type="date"], input[type="search"], select, textarea {
  width: 100%; padding: 10px 12px; background: transparent; color: var(--fg);
  border: 0; border-bottom: 2px solid var(--border);
  font-family: var(--font-body); font-size: .96rem; line-height: 1.6;
  transition: border-bottom-width .1s linear;
}
textarea { resize: vertical; min-height: 72px; border: 2px solid var(--border); }
input:focus, select:focus, textarea:focus { outline: none; border-bottom-width: 4px; }
textarea:focus { border-width: 3px; }
input[type="range"] { width: 100%; accent-color: var(--fg); }

.tag-picker { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 6px; }
.tag-picker button {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .08em;
  padding: 6px 12px; cursor: pointer; background: transparent; color: var(--muted-fg);
  border: 1px solid var(--border-light); transition: background-color .1s linear, color .1s linear;
}
.tag-picker button:hover { border-color: var(--border); color: var(--fg); }
.tag-picker button.on { background: var(--invert-bg); color: var(--invert-fg); border-color: var(--invert-bg); }

/* 呼吸 */
.breathe-stage { display: grid; place-items: center; padding: 28px 0 12px; min-height: 260px; }
.breathe-ring { position: relative; width: 220px; height: 220px; display: grid; place-items: center; }
.breathe-circle {
  position: absolute; inset: 0; border-radius: 50%;
  background: var(--fg); opacity: .1;
  transform: scale(.5); transition: transform 4s linear, opacity .3s linear;
}
.breathe-ring:not(.idle) .breathe-circle { opacity: .16; }
.breathe-circle.grow { transform: scale(1); }
.breathe-core { position: relative; z-index: 2; text-align: center; }
.breathe-phase {
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .2em;
  text-transform: uppercase; color: var(--muted-fg);
}
.breathe-count { font-family: var(--font-display); font-size: 3rem; line-height: 1.1; }
.breathe-info { text-align: center; color: var(--muted-fg); font-size: .88rem; }
.breathe-stats {
  display: flex; gap: 28px; justify-content: center; margin-top: 12px;
  font-family: var(--font-mono); font-size: .7rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--muted-fg);
}
.breathe-stats b { color: var(--fg); }

.chart-wrap { position: relative; height: 230px; margin: 8px 0; }
canvas { max-width: 100%; filter: grayscale(1); }

.record-list { display: grid; gap: 0; margin-top: 16px; }
.record { border-top: 1px solid var(--border-light); padding: 14px 0; font-size: .9rem; }
.record-top { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; }
.record-date { font-family: var(--font-mono); font-size: .74rem; letter-spacing: .08em; }
.record-body { color: var(--muted-fg); margin-top: 5px; white-space: pre-wrap; line-height: 1.65; }
.record-body b { color: var(--fg); font-weight: 700; }
.mood-dot { display: inline-block; width: 9px; height: 9px; margin-right: 7px; border: 1px solid var(--border); }
.empty { border: 1px dashed var(--border-light); padding: 22px; text-align: center; color: var(--muted-fg); font-size: .9rem; }

/* 番茄钟 */
.timer-display {
  font-family: var(--font-display); font-size: 4.5rem; line-height: 1;
  text-align: center; letter-spacing: -.03em; margin: 12px 0 20px;
}
.timer-bar { height: 4px; background: var(--border-light); overflow: hidden; margin-bottom: 16px; }
.timer-bar i { display: block; height: 100%; width: 0; background: var(--fg); transition: width .25s linear; }
.timer-display.break { opacity: .5; }
.task-list { display: grid; gap: 0; margin-top: 14px; }
.task-item {
  display: flex; align-items: center; gap: 12px; padding: 11px 0;
  border-top: 1px solid var(--border-light); font-size: .92rem;
}
.task-item.done span.t { text-decoration: line-through; color: var(--muted-fg); }
.task-item span.t { flex: 1; }
.task-item .poms {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--muted-fg);
}

/* 结果框 */
.result-box { border: 2px solid var(--border); padding: 22px 24px; margin-top: 20px; }
.result-score { font-family: var(--font-display); font-size: 2.6rem; line-height: 1.1; margin-bottom: 8px; }

/* ---------- 11. 读者想说 ---------- */
.letters { margin-top: 1rem; }
.letters__lead { font-size: 1.05rem; max-width: 44rem; }
.letters__prompts {
  border: 1px solid var(--border-light); padding: 18px 22px; margin: 0 0 24px;
}
.letters__prompts-title {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .14em;
  text-transform: uppercase; color: var(--muted-fg); margin: 0 0 10px;
}
.letters__prompts ul { margin: 0; padding-left: 1.2em; }
.letters__prompts li { font-size: .95rem; }
.letters__form { margin-bottom: 10px; max-width: 44rem; }
.letters__note { font-size: .88rem; color: var(--muted-fg); max-width: 44rem; }

.letters__mine {
  margin: 30px 0 0; padding: 20px 22px; border: 1px solid var(--border);
}
.letters__mine h3 {
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .16em;
  text-transform: uppercase; font-weight: 500; margin: 0 0 6px;
  display: flex; align-items: center; gap: 10px;
}
.letters__mine-note { font-size: .84rem; color: var(--muted-fg); margin: 0 0 10px; }
.letters__list { display: grid; }

.letter { border-top: 1px solid var(--border-light); padding: 16px 0; }
.letter:first-child { border-top: 0; padding-top: 0; }
.letter__meta { display: flex; align-items: center; gap: 12px; margin-bottom: 6px; flex-wrap: wrap; }
.letter__name { font-weight: 700; font-size: .94rem; }
.letter__date {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .1em; color: var(--muted-fg);
}
.letter__text { margin: 0; font-size: .96rem; white-space: pre-wrap; }
.letter__reply {
  margin: 10px 0 0; padding-left: 16px; border-left: 3px solid var(--border);
  font-size: .92rem; color: var(--muted-fg);
}
.letter__reply-label {
  display: block; font-family: var(--font-mono); font-size: .62rem;
  letter-spacing: .16em; text-transform: uppercase; color: var(--fg); margin-bottom: 3px;
}
.letter--mine .letter__meta { justify-content: space-between; }
.letter--mine .letter__text { font-size: .94rem; }

.letters__wall-title {
  font-size: 1.05rem; margin: 2.4rem 0 .4rem;
}
.letters__wall-note { font-size: .86rem; color: var(--muted-fg); margin: 0 0 12px; }
.letters__wall { max-width: 44rem; }
.letters__empty {
  border: 1px dashed var(--border-light); padding: 22px; text-align: center;
  color: var(--muted-fg); font-size: .9rem;
}
.letters__embed { margin-top: 32px; }
.letters__embed h3 {
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .16em;
  text-transform: uppercase; font-weight: 500; margin: 0 0 12px;
  padding-top: 16px; border-top: 1px solid var(--border-light);
}

/* ---------- 12. 资源库 ---------- */
.res-cat { margin: 0 0 12px; scroll-margin-top: calc(var(--header-h) + 24px); }
.res-cat > h2 { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.res-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(20rem, 1fr)); gap: 0; }
.res-item {
  border: 1px solid var(--border-light); margin: -1px 0 0 -1px; padding: 16px 18px;
  transition: background-color .1s linear, color .1s linear;
}
.res-item:hover { background: var(--muted-bg); }
.res-item .res-name { font-weight: 700; font-size: .96rem; display: flex; align-items: baseline; gap: 8px; flex-wrap: wrap; }
.res-item .res-name a { border: 0; }
.res-item .res-name a:hover { border-bottom: 1px solid var(--fg); }
.res-item .res-by { font-family: var(--font-mono); font-size: .66rem; letter-spacing: .08em; color: var(--muted-fg); font-weight: 400; }
.res-item .res-desc { font-size: .9rem; color: var(--muted-fg); margin: 6px 0 0; line-height: 1.7; }
.res-item .res-tags { margin-top: 10px; display: flex; gap: 6px; flex-wrap: wrap; }

/* ---------- 13. 热线 ---------- */
.hotline {
  display: flex; align-items: center; justify-content: space-between; gap: 20px; flex-wrap: wrap;
  border-top: 1px solid var(--border-light); padding: 18px 0;
}
.hotline:last-of-type { border-bottom: 1px solid var(--border-light); }
.hotline .num { font-family: var(--font-display); font-size: 1.9rem; line-height: 1.1; letter-spacing: -.02em; }
.hotline .meta { font-size: .88rem; color: var(--muted-fg); }

/* ---------- 14. 页脚与浮层 ---------- */
.site-footer { border-top: 8px solid var(--border); margin-top: 80px; }
.footer__inner {
  max-width: var(--grid-max); margin: 0 auto; padding: 48px var(--pad-x) 32px;
  display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 32px;
}
.footer__mark { font-family: var(--font-display); font-size: 1.4rem; font-weight: 700; margin: 0 0 8px; }
.footer__col p { font-size: .9rem; color: var(--muted-fg); margin: 0 0 6px; }
.footer__bottom {
  max-width: var(--grid-max); margin: 0 auto; padding: 16px var(--pad-x) 40px;
  border-top: 1px solid var(--border-light);
  display: flex; flex-wrap: wrap; gap: 20px;
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--muted-fg);
}
.footer__bottom a { border: 0; color: var(--muted-fg); }
.footer__bottom a:hover { color: var(--fg); }

.back-top {
  position: fixed; right: 24px; bottom: 24px; z-index: 100;
  width: 46px; height: 46px; cursor: pointer;
  background: var(--bg); color: var(--fg); border: 2px solid var(--border);
  font-family: var(--font-mono); font-size: 1rem;
  transition: background-color .1s linear, color .1s linear;
}
.back-top:hover { background: var(--invert-bg); color: var(--invert-fg); }

.toast {
  position: fixed; left: 50%; bottom: 32px; transform: translateX(-50%) translateY(8px);
  background: var(--invert-bg); color: var(--invert-fg);
  border: 2px solid var(--invert-bg); padding: 12px 20px;
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .1em;
  z-index: 300; opacity: 0; transition: opacity .1s linear, transform .1s linear; pointer-events: none;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- 15. 打印 ---------- */
.print-area { display: none; }
body.printing-area .site-header,
body.printing-area .md-sidebar,
body.printing-area .site-footer,
body.printing-area .md-main,
body.printing-area .back-top { display: none !important; }
body.printing-area .print-area { display: block !important; padding: 12px; }
body.printing-area::before, body.printing-area::after { display: none; }

@media print {
  body { padding-top: 0; background: #fff; color: #000; font-size: 11.5pt; }
  body::before, body::after { display: none; }
  .site-header, .md-sidebar, .site-footer, .back-top,
  .md-actions, .md-prevnext, .signoff, .md-breadcrumbs, .letters, .tool-head .btn { display: none !important; }
  .md-container { display: block; padding: 0; max-width: none; }
  .md-main { padding: 0; }
  .md-content h1 { font-size: 24pt; }
  .md-content h2 { font-size: 15pt; border-top-width: 2px; }
  .md-card, .tool-card, .admonition, .res-item, table { break-inside: avoid; }
  .admonition--idea { background: #fff !important; color: #000 !important; border-color: #000 !important; }
  .admonition--idea .admonition-title, .admonition--idea strong { color: #000 !important; }
  a { color: #000; border: 0; }
}

/* ---------- 16. 响应式 ---------- */
@media (max-width: 1180px) {
  .md-container { grid-template-columns: var(--nav-w) minmax(0, 1fr); }
  .md-sidebar--secondary { display: none; }
}
@media (max-width: 960px) {
  :root { --pad-x: 20px; --gap: 0px; }
  .md-container { grid-template-columns: minmax(0, 1fr); }
  .icon-btn { display: grid; }
  .md-sidebar--primary {
    position: fixed; top: var(--header-h); left: 0; bottom: 0; width: min(88vw, 340px);
    height: auto; background: var(--bg); z-index: 115;
    padding: 0 20px 32px; border-right: 2px solid var(--border);
    transform: translateX(-102%); transition: transform .1s linear;
  }
  .md-sidebar--primary .md-sidebar__scroll { padding: 24px 0 40px; }
  .md-sidebar--primary.md-sidebar--open { transform: translateX(0); }
  .brand__sub { display: none; }
  .md-search { width: 180px; }
}
@media (max-width: 720px) {
  body { font-size: 16px; }
  .md-main { padding: 32px 0 64px; }
  .idea-grid { grid-template-columns: 1fr; }
  .step { padding-left: 46px; }
  .md-prevnext { grid-template-columns: 1fr; }
  .md-prevnext .prev { border-right: 0; border-bottom: 1px solid var(--border-light); }
  .md-prevnext .next { grid-column: 1; text-align: left; }
  .tool-card { padding: 18px 16px; }
  .timer-display { font-size: 3.4rem; }
  .footer__inner { padding: 32px var(--pad-x) 24px; }

  /* 移动端搜索：收成窄输入框（保留"搜索"提示），聚焦后展开整行 */
  .md-search { width: 96px; margin-left: auto; }
  .md-search input {
    height: 40px; padding: 0; font-size: .84rem;
    border: 0; border-bottom: 2px solid var(--border);
  }
  .md-search__kbd { display: none; }
  .md-search.md-search--active {
    position: fixed; left: 0; right: 0; top: 0; height: var(--header-h);
    width: auto; margin: 0; padding: 10px var(--pad-x);
    background: var(--bg); border-bottom: 2px solid var(--border); z-index: 130;
    display: flex; align-items: center;
  }
  .md-search.md-search--active input {
    width: 100%; height: 40px; padding: 0; font-size: 1rem;
    border: 0; border-bottom: 2px solid var(--border);
  }
  .md-search__output { top: calc(100% + 4px); left: var(--pad-x); right: var(--pad-x); width: auto; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .001ms !important; transition-duration: .001ms !important; }
  html { scroll-behavior: auto; }
}