/* ==========================================================================
   Microsoft Lab —「铝合金」
   Apple 官网 / MacBook 的气质：浅灰底、纯白卡片、1px 发丝线、两层柔和阴影、圆角、磨砂玻璃顶栏。
   机械感来自细节：边缘高光（卡片顶部 1px 白线）、实体键帽、分段控件、开关、macOS 窗口三圆点。
   每个软件有自己的颜色（--a）：图标方块、选中项、链接、重点。
   容器规则：顶栏 / 各版块 / 课程窗口 / 页尾 共用 --max + --gutter，左右边缘永远对齐。
   改配色：只动 :root、html[data-mode="dark"] 和 [data-app="…"] 三处。
   ========================================================================== */

:root {
  --bg: #F5F5F7;
  --paper: #FFFFFF;
  --paper-2: #FAFAFC;
  --card: #FFFFFF;
  --ink: #1D1D1F;
  --ink-2: #424245;
  --ink-3: #6E6E73;
  --line: #E1E1E6;
  --line-soft: #EDEDF1;
  --glass: rgba(255, 255, 255, .72);       /* 磨砂玻璃 */
  --seg: rgba(60, 60, 67, .08);            /* 分段控件底 */
  --hl-edge: rgba(255, 255, 255, .9);      /* 铝合金倒角高光 */
  --good: #1D8348;  --good-soft: #E6F4EC;
  --bad:  #C0392B;  --bad-soft:  #FCEBE9;
  --warn: #9A6200;  --warn-soft: #FFF4DB;

  /* 软件色：每个软件只设 --a，其余自动推导 */
  --a: #0071E3;
  --a-on: #FFFFFF;
  --a-soft: color-mix(in srgb, var(--a) 9%, var(--paper));

  --font-head: "JetBrains Mono", "SF Mono", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", ui-monospace, monospace;
  --font-body: "JetBrains Mono", "SF Mono", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", ui-monospace, monospace;
  --font-mono: "JetBrains Mono", "SF Mono", ui-monospace, Consolas, monospace;

  /* 字号阶梯：笔记正文 + 「代码画界面」组件统一引用这套 token，不再各写各的字面值 */
  --fs-2xs: 10px;    /* 极小：微标、角标、面包屑类装饰文字 */
  --fs-xs:  11px;    /* 小标签：按钮英文名、图表坐标轴、下拉菜单子文字 */
  --fs-sm:  12.5px;  /* 次要说明：图注、公式栏、右键菜单、步骤号徽章 */
  --fs-base: 14px;   /* 正文基准：段落、列表、代码块 */
  --fs-md:  15px;    /* 略强调：callout、表格、术语弹窗 */
  --fs-lg:  17px;    /* H3 子标题、术语卡英文名 */
  --fs-xl:  21px;    /* H2 节标题 */
  --fs-code: .875em; /* 行内代码 / 快捷键 / 菜单路径统一倍数 */

  --max: 1600px;                 /* 唯一的容器宽度 */
  --gutter: 24px;                /* 唯一的左右留白 */
  --gbar-h: 68px;     /* 上下各 15px 内边距 + 38px 内容 */
  --title-h: 44px;
  --side-w: 260px;
  --toc-w: 232px;
  --read-w: 100%;
  --radius: 18px;                /* 卡片 */
  --radius-sm: 10px;             /* 控件 */
  --radius-lg: 28px;             /* 大块 */
  --shadow: 0 1px 2px rgba(0, 0, 0, .04), 0 8px 24px rgba(0, 0, 0, .06);
  --shadow-lg: 0 2px 4px rgba(0, 0, 0, .04), 0 24px 60px rgba(0, 0, 0, .12);
  --ease: cubic-bezier(.22, 1, .36, 1);
  color-scheme: light;
}
html[data-mode="dark"] {
  --bg: #000000; --paper: #1C1C1E; --paper-2: #232326; --card: #1C1C1E;
  --ink: #F5F5F7; --ink-2: #D1D1D6; --ink-3: #98989D;
  --line: #38383A; --line-soft: #2C2C2E;
  --glass: rgba(28, 28, 30, .72); --seg: rgba(255, 255, 255, .1); --hl-edge: rgba(255, 255, 255, .08);
  --good: #4CD08A; --good-soft: #10301F; --bad: #FF8B7E; --bad-soft: #3F1B17; --warn: #F2B65A; --warn-soft: #3A2C10;
  --a-soft: color-mix(in srgb, var(--a) 18%, var(--paper));
  --shadow: 0 1px 2px rgba(0, 0, 0, .5), 0 8px 24px rgba(0, 0, 0, .45);
  --shadow-lg: 0 2px 4px rgba(0, 0, 0, .5), 0 24px 60px rgba(0, 0, 0, .6);
  color-scheme: dark;
}

/* 各软件主色 */
[data-app="excel"]      { --a: #1A7F45; }
[data-app="word"]       { --a: #2563D4; }
[data-app="powerpoint"] { --a: #D24726; }
[data-app="outlook"]    { --a: #0A6CC4; }
[data-app="onenote"]    { --a: #7F3FBF; }
[data-app="teams"]      { --a: #5057C9; }
[data-app="onedrive-and-sharepoint"] { --a: #0A7E92; }
[data-app="power-bi"]   { --a: #A87400; }
[data-app="home"]       { --a: #0071E3; }
html[data-mode="dark"] [data-app="excel"]      { --a: #5FD08A; --a-on: #0B1A12; }
html[data-mode="dark"] [data-app="word"]       { --a: #8FB0FF; --a-on: #0E1420; }
html[data-mode="dark"] [data-app="powerpoint"] { --a: #FF9A6E; --a-on: #1E0D06; }
html[data-mode="dark"] [data-app="outlook"]    { --a: #6CC0F5; --a-on: #07141F; }
html[data-mode="dark"] [data-app="onenote"]    { --a: #C9A4F5; --a-on: #150C20; }
html[data-mode="dark"] [data-app="teams"]      { --a: #A3AAFF; --a-on: #0C0E22; }
html[data-mode="dark"] [data-app="onedrive-and-sharepoint"] { --a: #5CCFE0; --a-on: #061A1E; }
html[data-mode="dark"] [data-app="power-bi"]   { --a: #F2C811; --a-on: #1E1803; }
html[data-mode="dark"] [data-app="home"]       { --a: #2997FF; --a-on: #FFFFFF; }

/* ---- 基础 ---- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: calc(var(--gbar-h) + var(--title-h) + 24px); overflow-x: clip; }
body.v2 { margin: 0; background: var(--bg); color: var(--ink); font-family: var(--font-body); font-size: var(--fs-base); line-height: 1.85; -webkit-font-smoothing: antialiased; overflow-x: clip; }
img, svg { max-width: 100%; }
a { color: var(--a); text-underline-offset: .2em; text-decoration-thickness: 1px; }
button { font: inherit; color: inherit; }
:focus-visible { outline: 3px solid color-mix(in srgb, var(--a) 55%, transparent); outline-offset: 2px; border-radius: 6px; }
.skip-link { position: absolute; left: -9999px; top: 8px; background: var(--ink); color: var(--paper); padding: 8px 14px; z-index: 300; border-radius: 10px; }
.skip-link:focus { left: 8px; }
h1, h2, h3, h4 { font-family: var(--font-head); line-height: 1.35; margin: 0; letter-spacing: -.01em; }
[hidden] { display: none !important; }
.muted { color: var(--ink-3); }
mark { background: color-mix(in srgb, #FFD60A 45%, transparent); color: inherit; padding: 0 2px; border-radius: 4px; }

/* 标题里的重点词：渐变色文字 */
.hl { background: linear-gradient(90deg, var(--a), color-mix(in srgb, var(--a) 55%, #A855F7)); -webkit-background-clip: text; background-clip: text; color: transparent; }

/* ---- 顶栏：磨砂玻璃 ---- */
.gbar { position: sticky; top: 0; z-index: 70; height: var(--gbar-h); padding: 15px 0; background: var(--glass); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px); border-bottom: 1px solid var(--line); }
.gbar-in { max-width: var(--max); height: 100%; margin: 0 auto; padding: 0 var(--gutter); display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr); align-items: center; gap: 18px; }
.brand { display: inline-flex; align-items: center; gap: 9px; text-decoration: none; color: var(--ink); font-family: var(--font-head); font-weight: 400; font-size: 16.5px; white-space: nowrap; letter-spacing: -.01em; }
.brand img { border-radius: 7px; }
.brand b { font-weight: 400; color: var(--ink-3); }
/* 导航：分段控件，当前项像拨到位的滑块 */
.gnav { display: flex; justify-self: center; align-items: center; max-width: 100%; gap: 2px; padding: 3px; background: var(--seg); border-radius: 12px; overflow-x: auto; scrollbar-width: none; }
.gnav::-webkit-scrollbar { display: none; }
.gnav a { flex: none; padding: 4px 12px; text-decoration: none; color: var(--ink-2); font-size: 13.5px; font-weight: 400; white-space: nowrap; border-radius: 9px; transition: background .2s var(--ease), color .2s, box-shadow .2s; }
.gnav a:hover { color: var(--ink); background: color-mix(in srgb, var(--paper) 55%, transparent); }
.gnav a.on { background: var(--paper); color: var(--ink); font-weight: 400; box-shadow: 0 1px 2px rgba(0, 0, 0, .12), 0 0 0 .5px rgba(0, 0, 0, .06); }
.gtools { justify-self: end; display: flex; gap: 6px; }
.gbtn { display: inline-flex; align-items: center; gap: 7px; min-height: 36px; min-width: 36px; padding: 0 11px; border: 0; background: var(--seg); border-radius: 10px; cursor: pointer; justify-content: center; color: var(--ink-2); transition: background .15s, transform .15s var(--ease); }
.gbtn:hover { background: color-mix(in srgb, var(--ink) 12%, transparent); color: var(--ink); }
.gbtn:active { transform: scale(.96); }
.gbtn[aria-pressed="true"] { background: var(--a-soft); color: var(--a); }
.gl { font-size: 13.5px; }
.i-sun { display: none; }
html[data-mode="dark"] .i-sun { display: block; }
html[data-mode="dark"] .i-moon { display: none; }

/* 搜索浮层 */
.search-overlay { position: fixed; inset: 0; z-index: 200; display: flex; justify-content: center; align-items: flex-start; padding: 9vh 16px 16px; }
.search-backdrop { position: absolute; inset: 0; background: rgba(0, 0, 0, .35); -webkit-backdrop-filter: blur(6px); backdrop-filter: blur(6px); }
.search-panel { position: relative; width: min(720px, 100%); max-height: 78vh; display: flex; flex-direction: column; background: var(--paper); border: 1px solid var(--line); border-radius: 20px; box-shadow: var(--shadow-lg); overflow: hidden; }
.search-box { display: flex; gap: 12px; align-items: center; padding: 8px 14px 8px 18px; border-bottom: 1px solid var(--line); color: var(--ink-3); }
.search-input { flex: 1; min-width: 0; border: 0; outline: 0; background: transparent; font: inherit; font-size: 16px; color: var(--ink); height: 44px; }
.search-esc { border: 0; background: var(--seg); border-radius: 9px; padding: 4px 12px; min-height: 32px; cursor: pointer; font-size: 13px; }
.search-esc:hover { background: color-mix(in srgb, var(--ink) 12%, transparent); }
.search-results { overflow-y: auto; padding: 6px; }
.search-empty { padding: 26px 16px; color: var(--ink-3); text-align: center; margin: 0; }
.search-hit { display: block; padding: 10px 12px; text-decoration: none; color: var(--ink); border-radius: 12px; }
.search-hit:hover { background: var(--a-soft); }
.hit-app { display: inline-block; font-size: 12px; font-weight: 400; padding: 0 9px; border-radius: 999px; background: var(--a-soft); color: var(--a); margin-bottom: 2px; }
.hit-title { display: block; font-weight: 400; line-height: 1.5; }
.hit-snippet { display: block; font-size: 13.5px; color: var(--ink-2); line-height: 1.6; }

/* ---- 页尾 ---- */
.gfoot { margin-top: 56px; border-top: 1px solid var(--line); background: var(--paper); color: var(--ink-3); font-size: 13px; }
.gfoot-in { max-width: var(--max); margin: 0 auto; padding: 22px var(--gutter) 30px; display: flex; gap: 6px 16px; flex-wrap: wrap; }
.gfoot b { color: var(--ink); font-weight: 400; }

/* ---- 首页 ---- */
.start { background: linear-gradient(180deg, var(--paper), var(--bg)); }
.start-in { max-width: var(--max); margin: 0 auto; padding: 56px var(--gutter) 28px; }
.start-hello { text-align: center; }
.kicker { margin: 0 0 10px; font-size: 13px; font-weight: 400; color: var(--ink-3); letter-spacing: .02em; }
.start-hello h1 { font-size: clamp(30px, 4.6vw, 52px); font-weight: 300; letter-spacing: -.01em; line-height: 1.12; }
.lede { font-size: 17.5px; color: var(--ink-3); margin: 14px auto 0; max-width: 34em; }
.continue { display: inline-grid; gap: 0; margin-top: 20px; padding: 10px 18px; background: var(--paper); border: 1px solid var(--line); border-radius: 16px; box-shadow: var(--shadow); text-decoration: none; color: var(--ink); line-height: 1.5; text-align: left; transition: transform .2s var(--ease); }
.continue:hover { transform: translateY(-2px); }
.c-l { font-size: 12px; font-weight: 400; color: var(--a); }
.c-t { font-weight: 400; }
.c-a { font-size: 13px; color: var(--ink-3); }

.tiles { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 18px; margin-top: 40px; }
.tile { display: grid; grid-template-columns: auto 1fr; grid-template-rows: auto auto auto; column-gap: 14px; row-gap: 2px; padding: 20px; background: linear-gradient(180deg, var(--paper), var(--paper-2)); border: 1px solid var(--line); border-radius: 22px; box-shadow: inset 0 1px 0 var(--hl-edge), var(--shadow); text-decoration: none; color: var(--ink); transition: transform .3s var(--ease), box-shadow .3s var(--ease); }
.tile:hover { transform: translateY(-4px); box-shadow: inset 0 1px 0 var(--hl-edge), var(--shadow-lg); }
.tile:active { transform: translateY(-1px) scale(.99); }
.tile-ic { grid-row: 1 / 4; width: 52px; height: 52px; display: grid; place-items: center; border-radius: 14px; background: linear-gradient(160deg, color-mix(in srgb, var(--a) 72%, #fff), var(--a)); color: var(--a-on); box-shadow: inset 0 1px 0 rgba(255, 255, 255, .35), 0 3px 8px color-mix(in srgb, var(--a) 35%, transparent); align-self: start; }
.tile-ic svg { width: 28px; height: 28px; }
.tile-n { font-family: var(--font-head); font-weight: 400; font-size: 16.5px; line-height: 1.3; }
.tile-t { font-size: 13.5px; color: var(--ink-3); line-height: 1.55; }
.tile-c { font-size: 12.5px; color: var(--ink-3); margin-top: 4px; }

.band { max-width: var(--max); margin: 0 auto; padding: 36px var(--gutter) 0; }
.band-in { display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr); gap: 36px; }
.h-sec { font-size: 20px; font-weight: 300; margin: 0 0 14px; letter-spacing: -.01em; }
.filelist { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: inset 0 1px 0 var(--hl-edge), var(--shadow); overflow: hidden; }
.frow { display: flex; align-items: center; gap: 14px; padding: 10px 16px; min-height: 54px; text-decoration: none; color: var(--ink); border-top: 1px solid var(--line-soft); position: relative; transition: background .15s; }
.frow:first-child { border-top: 0; }
a.frow:hover { background: var(--a-soft); }
.f-no { flex: none; min-width: 30px; font-size: 13.5px; font-weight: 400; color: var(--ink-3); text-align: right; font-variant-numeric: tabular-nums; }
.f-t { flex: 1; min-width: 0; display: grid; line-height: 1.5; }
.f-t b { font-weight: 400; }
.f-t small { color: var(--ink-3); font-size: 13px; }
.f-app { flex: none; min-width: 7.5em; font-size: 12px; font-weight: 400; color: var(--a); background: var(--a-soft); padding: 1px 10px; border-radius: 999px; text-align: center; white-space: nowrap; }
.f-m { font-size: 13px; color: var(--ink-3); white-space: nowrap; }
.f-done { display: none; width: 22px; height: 22px; place-items: center; border-radius: 50%; background: var(--good); color: #fff; font-size: 12px; font-weight: 400; }
.frow.is-done .f-done { display: grid; }
.frow.is-done .f-no { color: var(--good); }

.path2 { list-style: none; margin: 0; padding: 0; counter-reset: p; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: inset 0 1px 0 var(--hl-edge), var(--shadow); overflow: hidden; }
.path2 li { counter-increment: p; padding: 14px 16px 14px 58px; position: relative; display: grid; line-height: 1.55; border-top: 1px solid var(--line-soft); }
.path2 li:first-child { border-top: 0; }
.path2 li::before { content: counter(p); position: absolute; left: 16px; top: 14px; width: 28px; height: 28px; border-radius: 50%; background: var(--a-soft); color: var(--a); display: grid; place-items: center; font-weight: 400; font-size: 14px; }
.path2 span { color: var(--ink-3); font-size: 13.5px; }

/* ---- 软件目录页 ---- */
/* 分页签：当前标签填软件色 */
.appbar { background: linear-gradient(180deg, color-mix(in srgb, var(--a) 12%, var(--paper)), var(--bg)); }
.appbar-in { max-width: var(--max); margin: 0 auto; padding: 18px var(--gutter) 30px; }
.crumbs { font-size: 13px; display: flex; flex-wrap: wrap; gap: 2px 6px; line-height: 1.5; color: var(--ink-3); }
.crumbs a { color: var(--ink-3); text-decoration: none; }
.crumbs a:hover { color: var(--a); }
.appbar-row { display: flex; align-items: center; gap: 20px; margin-top: 14px; flex-wrap: wrap; }
.appbar .tile-ic { width: 68px; height: 68px; border-radius: 18px; }
.appbar .tile-ic svg { width: 38px; height: 38px; }
.appbar-t { flex: 1; min-width: 220px; }
.appbar h1 { font-size: 32px; font-weight: 300; letter-spacing: -.01em; }
.appbar-t p { margin: 4px 0 0; color: var(--ink-3); font-size: 15px; }
.btn-go { display: inline-flex; align-items: center; min-height: 44px; padding: 0 24px; border-radius: 999px; background: var(--a); color: var(--a-on); font-weight: 400; text-decoration: none; box-shadow: 0 2px 8px color-mix(in srgb, var(--a) 40%, transparent); transition: transform .2s var(--ease), box-shadow .2s var(--ease); }
.btn-go:hover { transform: translateY(-2px); box-shadow: 0 8px 20px color-mix(in srgb, var(--a) 40%, transparent); }
.btn-go:active { transform: scale(.97); }
.stages { max-width: var(--max); margin: 0 auto; padding: 8px var(--gutter) 0; display: grid; gap: 22px; }
.stage-h { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; margin-bottom: 14px; }
.stage-h h2 { font-size: 22px; font-weight: 300; }
.stage-h p { margin: 0; color: var(--ink-3); font-size: 14px; }

/* 分页签 */
.tablist { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.tab { display: inline-flex; align-items: center; gap: 8px; min-height: 40px; padding: 0 18px; border: 1px solid var(--line); border-radius: 999px; background: var(--paper); color: var(--ink-2); cursor: pointer; font-size: 14px; transition: background .2s var(--ease), color .2s, transform .15s var(--ease); }
.tab:hover { background: var(--a-soft); color: var(--ink); }
.tab:active { transform: scale(.97); }
.tab[aria-selected="true"] { background: var(--a); border-color: var(--a); color: var(--a-on); }
.tab-c { font-size: 12px; opacity: .7; }
.tabpanel[hidden] { display: none; }

.lg { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: inset 0 1px 0 var(--hl-edge), var(--shadow); margin: 0 0 12px; overflow: hidden; }
.lg > summary { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 12px; min-height: 52px; padding: 6px 18px; font-weight: 400; transition: background .15s; }
.lg > summary::-webkit-details-marker { display: none; }
.lg > summary::before { content: "›"; display: inline-block; width: 18px; font-size: 20px; line-height: 1; color: var(--a); transition: transform .2s var(--ease); }
.lg[open] > summary::before { transform: rotate(90deg); }
.lg > summary:hover { background: var(--a-soft); }
.lg-n { flex: 1; }
.lg-c { font-size: 13px; font-weight: 400; color: var(--ink-3); }
.lg .filelist { border: 0; border-top: 1px solid var(--line-soft); border-radius: 0; box-shadow: none; }
.lg-in { padding: 0 12px 12px; }
.lg-in .lg { background: var(--paper-2); box-shadow: none; border-radius: 14px; margin-bottom: 8px; }

/* ---- 课程页：macOS 窗口 ---- */
.read-progress { position: fixed; left: 0; right: 0; top: var(--gbar-h); height: 3px; z-index: 65; }
.read-progress span { display: block; height: 100%; width: 0; background: var(--a); border-radius: 0 3px 3px 0; }
.win { width: min(100% - 2 * var(--gutter), var(--max) - 2 * var(--gutter)); margin: 22px auto 0; background: var(--paper); border: 1px solid var(--line); border-radius: 18px 18px 0 0; box-shadow: var(--shadow-lg); position: relative; }
.win-title { position: sticky; top: var(--gbar-h); z-index: 40; display: flex; align-items: center; gap: 12px; height: var(--title-h); padding: 0 16px; background: linear-gradient(180deg, var(--paper), var(--paper-2)); border-bottom: 1px solid var(--line); border-radius: 17px 17px 0 0; font-size: 13.5px; font-weight: 400; color: var(--ink-2); }
.wt-lights { display: inline-flex; gap: 8px; flex: none; }
.wt-lights i { width: 12px; height: 12px; border-radius: 50%; box-shadow: inset 0 0 0 .5px rgba(0, 0, 0, .18); }
.wt-lights i:nth-child(1) { background: #FF5F57; }
.wt-lights i:nth-child(2) { background: #FEBC2E; }
.wt-lights i:nth-child(3) { background: #28C840; }
.wt-ic { display: inline-grid; place-items: center; width: 22px; height: 22px; border-radius: 6px; background: linear-gradient(160deg, color-mix(in srgb, var(--a) 72%, #fff), var(--a)); color: var(--a-on); flex: none; }
.wt-ic svg { width: 14px; height: 14px; display: block; }
.wt-name { flex: 1; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.wt-sep { opacity: .5; margin: 0 4px; }

.win-body { display: grid; grid-template-columns: var(--side-w) minmax(0, 1fr); align-items: start; }
.win-body.has-toc { grid-template-columns: var(--side-w) minmax(0, 1fr) var(--toc-w); }
.note-side { position: sticky; top: calc(var(--gbar-h) + var(--title-h)); height: calc(100vh - var(--gbar-h) - var(--title-h) - 48px); overflow-y: auto; border-right: 1px solid var(--line); background: var(--paper-2); }
.pane-in { padding: 12px 10px 30px; }
.pane-h { padding: 4px 10px 8px; font-weight: 400; font-size: 13.5px; }
.pane-h a { color: var(--ink); text-decoration: none; }
.pane-h a:hover { color: var(--a); }
.pane-gt { padding: 4px 10px; font-size: 12px; font-weight: 400; color: var(--ink-3); }
.sb-item { display: flex; gap: 10px; align-items: flex-start; padding: 6px 10px; border-radius: 8px; text-decoration: none; color: var(--ink-2); font-size: 13.5px; line-height: 1.5; transition: background .15s; }
.sb-item:hover { background: var(--seg); color: var(--ink); }
.sb-item.is-active { background: color-mix(in srgb, var(--a) 14%, transparent); color: var(--a); font-weight: 400; }
.sb-no { flex: none; min-width: 20px; font-size: 12px; color: var(--ink-3); padding-top: 1px; text-align: right; }
.sb-item.is-active .sb-no { color: inherit; }
.sb-item.is-done .sb-no { color: transparent; position: relative; }
.sb-item.is-done .sb-no::after { content: "✓"; position: absolute; right: 0; color: var(--good); font-weight: 400; }
.pane-in .sb-group { margin: 1px 0; }
.pane-in .sb-group > summary { list-style: none; cursor: pointer; display: flex; align-items: center; gap: 8px; min-height: 36px; padding: 4px 10px; border-radius: 8px; font-weight: 400; font-size: 13.5px; line-height: 1.4; }
.pane-in .sb-group > summary::-webkit-details-marker { display: none; }
.pane-in .sb-group > summary::before { content: "›"; width: 12px; font-size: 16px; line-height: 1; color: var(--ink-3); transition: transform .2s var(--ease); }
.pane-in .sb-group[open] > summary::before { transform: rotate(90deg); }
.pane-in .sb-group > summary:hover { background: var(--seg); }
.pane-in .sb-label { flex: 1; }
.pane-in .sb-count { font-size: 11.5px; font-weight: 400; color: var(--ink-3); }
.pane-in .sb-items { padding-left: 10px; }
.pane-in .sb-group .sb-group .sb-items { padding-left: 6px; }
.pane-in .sb-flat { padding-left: 0; }
.side-fab, .side-scrim { display: none; }

.note-main { min-width: 0; padding: 30px clamp(18px, 3.2vw, 48px) 40px; width: 100%; }
.doc-kicker { display: flex; flex-wrap: wrap; gap: 4px 10px; align-items: center; font-size: 13px; color: var(--ink-3); margin-bottom: 8px; }
.doc-head h1 { font-size: clamp(26px, 3vw, 34px); font-weight: 300; letter-spacing: -.01em; }
.doc-sum { font-size: 16.5px; color: var(--ink-3); margin: 8px 0 0; line-height: 1.75; }
.doc-head { padding-bottom: 18px; margin-bottom: 6px; border-bottom: 1px solid var(--line); }

/* 右侧目录 */
.note-toc { position: sticky; top: calc(var(--gbar-h) + var(--title-h)); max-height: calc(100vh - var(--gbar-h) - var(--title-h) - 48px); overflow-y: auto; padding: 26px 14px 24px 12px; border-left: 1px solid var(--line); font-size: 13px; line-height: 1.5; }
.toc-h { padding: 0 0 8px 10px; font-size: 12px; font-weight: 400; color: var(--ink-3); }
.note-toc ol { list-style: none; margin: 0; padding: 0; }
.note-toc a { display: block; padding: 5px 10px; color: var(--ink-3); text-decoration: none; border-radius: 8px; transition: background .15s, color .15s; }
.note-toc li.t3 a { padding-left: 22px; font-size: 12.5px; }
.note-toc a:hover { background: var(--seg); color: var(--ink); }
.note-toc a.is-current { color: var(--a); font-weight: 400; background: color-mix(in srgb, var(--a) 12%, transparent); }

.win-status { position: sticky; bottom: 0; z-index: 38; display: flex; align-items: center; gap: 10px; min-height: 48px; padding: 6px 14px; background: var(--glass); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px); border-top: 1px solid var(--line); border-radius: 0; font-size: 13px; color: var(--ink-3); }
.ws-sp { flex: 1; }
.ws-i { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.ws-btn { display: inline-flex; align-items: center; min-height: 34px; padding: 0 15px; border-radius: 999px; background: var(--seg); color: var(--ink); text-decoration: none; font-weight: 400; max-width: 38vw; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; transition: background .15s, transform .15s var(--ease); }
.ws-btn:hover { background: color-mix(in srgb, var(--ink) 12%, transparent); }
.ws-btn:active { transform: scale(.97); }
.ws-btn.primary { background: var(--a); color: var(--a-on); font-weight: 400; }
.ws-btn.primary:hover { background: color-mix(in srgb, var(--a) 88%, #000); }

/* ---- 课程正文 ---- */
.doc-body h2 { font-size: var(--fs-xl); font-weight: 300; margin: 2em 0 .6em; letter-spacing: -.01em; }
.doc-body h2:first-child { margin-top: 1.2em; }
.doc-body h3 { font-size: var(--fs-lg); font-weight: 300; margin: 1.5em 0 .4em; }
.doc-body h4 { font-weight: 300; }
.doc-body p { margin: 0 0 1em; }
.doc-body ul, .doc-body ol { margin: 0 0 1.1em; padding-left: 1.45em; }
.doc-body li { margin: .3em 0; }
.doc-body li::marker { color: var(--a); font-weight: 400; }
.doc-body strong { font-weight: 500; color: var(--ink); }
.doc-body hr, .doc-body .sec-divider, .doc-body .sub-divider, .doc-body .h3-rule { display: none; }
.doc-body code { font-family: var(--font-mono); font-size: var(--fs-code); padding: .1em .45em; border-radius: 6px; background: var(--seg); }
.doc-body .table-scroll { overflow-x: auto; border: 1px solid var(--line); border-radius: 14px; margin: 0 0 1.2em; }
.doc-body table.vocab { border-collapse: collapse; width: 100%; font-size: var(--fs-md); line-height: 1.6; min-width: 480px; }
.doc-body table.vocab th { text-align: left; background: var(--paper-2); padding: 9px 14px; border-bottom: 1px solid var(--line); white-space: nowrap; font-weight: 400; color: var(--ink-2); }
.doc-body table.vocab td { padding: 9px 14px; border-bottom: 1px solid var(--line-soft); vertical-align: top; }
.doc-body table.vocab tr:last-child td { border-bottom: 0; }
.callout { margin: 1.2em 0; padding: 12px 18px; border-radius: 14px; font-size: var(--fs-md); line-height: 1.75; }
.callout p { margin: 0; }
.callout-tip  { background: var(--good-soft); box-shadow: inset 4px 0 0 var(--good); }
.callout-warn { background: var(--bad-soft);  box-shadow: inset 4px 0 0 var(--bad); }
.callout-note { background: var(--warn-soft); box-shadow: inset 4px 0 0 var(--warn); }

/* 实体键帽 */
.keys { display: inline-flex; gap: 4px; align-items: center; margin: 0 2px; white-space: nowrap; }
.keys i { font-style: normal; color: var(--ink-3); font-size: var(--fs-code); }
kbd { display: inline-block; min-width: 1.9em; padding: .06em .55em .12em; text-align: center; font-family: var(--font-mono); font-size: var(--fs-code); line-height: 1.45; color: var(--ink); background: linear-gradient(180deg, var(--paper), var(--paper-2)); border: 1px solid color-mix(in srgb, var(--ink) 22%, transparent); border-bottom-width: 3px; border-radius: 7px; box-shadow: inset 0 1px 0 var(--hl-edge); }
.menu-path { display: inline-flex; flex-wrap: wrap; align-items: center; gap: 3px 5px; line-height: 1.5; }
.menu-path span { background: var(--a-soft); color: var(--a); font-weight: 400; font-size: var(--fs-code); padding: 0 .6em; border-radius: 999px; }
.menu-path i { font-style: normal; color: var(--ink-3); }

.formula, .code-wrap { position: relative; margin: 1.1em 0; border-radius: 14px; background: #1D1D1F; color: #F5F5F7; box-shadow: var(--shadow); }
.formula code { display: block; padding: 14px 80px 14px 18px; background: transparent; border: 0; color: inherit; font-size: var(--fs-md); line-height: 1.7; white-space: pre-wrap; word-break: break-all; }
.code-wrap pre { margin: 0; padding: 34px 18px 14px; overflow-x: auto; }
.code-wrap code { background: transparent; border: 0; padding: 0; color: inherit; font-size: var(--fs-base); white-space: pre; }
.code-wrap::before { content: attr(data-lang); position: absolute; left: 18px; top: 9px; font-size: var(--fs-xs); font-weight: 400; letter-spacing: .06em; color: #8E8E93; }
.copy-btn { position: absolute; right: 10px; top: 9px; min-height: 30px; padding: 0 12px; border-radius: 8px; border: 0; background: rgba(255, 255, 255, .12); color: #F5F5F7; font-size: var(--fs-sm); cursor: pointer; transition: background .15s; }
.copy-btn:hover { background: rgba(255, 255, 255, .22); }
.copy-btn.is-copied { background: #30D158; color: #04170D; font-weight: 400; }

.term { border-bottom: 2px dotted var(--a); cursor: help; }
.term:hover, .term:focus, .term.is-open { background: var(--a-soft); outline: 0; border-radius: 4px 4px 0 0; }
.term-pop { position: absolute; z-index: 150; max-width: min(320px, calc(100vw - 24px)); background: color-mix(in srgb, var(--ink) 92%, transparent); color: var(--paper); -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px); padding: 10px 14px; border-radius: 12px; font-size: var(--fs-base); line-height: 1.65; box-shadow: var(--shadow-lg); }
.term-pop::after { content: ""; position: absolute; left: var(--arrow-x, 20px); top: 100%; border: 7px solid transparent; border-top-color: color-mix(in srgb, var(--ink) 92%, transparent); }
.term-pop.is-below::after { top: auto; bottom: 100%; border-top-color: transparent; border-bottom-color: color-mix(in srgb, var(--ink) 92%, transparent); }
.term-pop b { display: block; font-size: var(--fs-sm); opacity: .7; }


.doc-body .overview { background: var(--a-soft); padding: 14px 20px 6px; margin: 0 0 1.5em; border-radius: 16px; }
.doc-body .overview-label { font-weight: 400; font-size: var(--fs-sm); color: var(--a); margin-bottom: 4px; }
.doc-body .overview ul { margin-bottom: .6em; }
.doc-body .overview p:last-child { margin-bottom: .6em; }
.doc-body .example-card { margin: 0 0 1em; padding: 12px 16px; border: 1px solid var(--line); border-radius: 14px; background: var(--paper-2); }
.doc-body img { border-radius: 14px; border: 1px solid var(--line); }
.doc-body pre.mermaid { background: var(--paper); border: 1px solid var(--line); border-radius: 14px; padding: 16px; overflow-x: auto; text-align: center; }
.doc-body blockquote { margin: 1.2em 0; padding: 10px 18px; border-radius: 14px; background: var(--paper-2); box-shadow: inset 4px 0 0 var(--line); }
.doc-body blockquote p { margin: 0; }
.doc-body .shot-note { margin: 1.2em 0; padding: 12px 18px; border: 1px dashed var(--ink-3); border-radius: 14px; background: var(--paper-2); }
.doc-body .shot-label { display: block; font-size: var(--fs-sm); font-weight: 400; color: var(--ink-3); }
.doc-body .shot-note p { margin: 0; font-size: var(--fs-base); color: var(--ink-2); }
.doc-body ol.steps { list-style: none; padding-left: 0; counter-reset: step; }
.doc-body ol.steps > li { counter-increment: step; position: relative; padding: 12px 16px 12px 58px; margin: 10px 0; background: var(--paper); border: 1px solid var(--line); border-radius: 16px; box-shadow: inset 0 1px 0 var(--hl-edge), var(--shadow); }
.doc-body ol.steps > li::before { content: counter(step); position: absolute; left: 16px; top: 12px; width: 30px; height: 30px; display: grid; place-items: center; border-radius: 50%; background: var(--a); color: var(--a-on); font-weight: 400; font-size: var(--fs-base); }

/* ---- 互动演示（样式在 demos.css，这里补布局） ---- */
.doc-body .demo { max-width: 100%; margin: 1.3em 0; }
.demo-title { margin: 6px 0 2px; font-weight: 400; font-size: var(--fs-lg); }
.doc-body .demo h2.demo-title { border: 0; padding: 0; margin: 6px 0 2px; font-size: var(--fs-lg); }

/* ---- 学完了：iOS 开关 ---- */
.done-bar { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin: 36px 0 0; padding: 14px 18px; background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); }
.done-btn { display: inline-flex; align-items: center; gap: 12px; min-height: 40px; padding: 0; background: transparent; border: 0; cursor: pointer; font-weight: 400; }
.done-box { position: relative; flex: none; width: 46px; height: 28px; border-radius: 999px; background: color-mix(in srgb, var(--ink) 22%, transparent); transition: background .25s var(--ease); }
.done-box::before { content: ""; position: absolute; left: 2px; top: 2px; width: 24px; height: 24px; border-radius: 50%; background: #fff; box-shadow: 0 1px 3px rgba(0, 0, 0, .3); transition: transform .25s var(--ease); }
.done-btn[aria-pressed="true"] .done-box { background: var(--good); }
.done-btn[aria-pressed="true"] .done-box::before { transform: translateX(18px); }
.done-btn[aria-pressed="true"] { color: var(--good); }

/* ---- 动效 ---- */
.js .reveal-ready { opacity: 0; transform: translateY(12px); transition: opacity .5s ease, transform .5s var(--ease); }
.js .reveal-ready.is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: no-preference) {
  @view-transition { navigation: auto; }
  ::view-transition-old(root) { animation: .2s ease both vt-out; }
  ::view-transition-new(root) { animation: .3s var(--ease) both vt-in; }
  html:active-view-transition-type(forward)::view-transition-old(root) { animation: .24s ease both vt-l-out; }
  html:active-view-transition-type(forward)::view-transition-new(root) { animation: .32s var(--ease) both vt-r-in; }
  html:active-view-transition-type(back)::view-transition-old(root) { animation: .24s ease both vt-r-out; }
  html:active-view-transition-type(back)::view-transition-new(root) { animation: .32s var(--ease) both vt-l-in; }
  html:active-view-transition-type(zoom)::view-transition-old(root) { animation: .26s ease both vt-zoom-out; }
  html:active-view-transition-type(zoom)::view-transition-new(root) { animation: .42s var(--ease) both vt-circle; }
  .gbar { view-transition-name: gbar; }
  ::view-transition-group(gbar) { animation-duration: 0s; }
}
@keyframes vt-out { to { opacity: 0 } }
@keyframes vt-in { from { opacity: 0; transform: translateY(8px) } }
@keyframes vt-l-out { to { opacity: 0; transform: translateX(-40px) } }
@keyframes vt-r-in { from { opacity: 0; transform: translateX(40px) } }
@keyframes vt-r-out { to { opacity: 0; transform: translateX(40px) } }
@keyframes vt-l-in { from { opacity: 0; transform: translateX(-40px) } }
@keyframes vt-zoom-out { to { opacity: 0; transform: scale(.97) } }
@keyframes vt-circle { from { clip-path: circle(0% at 50% 30%) } to { clip-path: circle(150% at 50% 30%) } }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; scroll-behavior: auto !important; }
  .js .reveal-ready { opacity: 1; transform: none; }
}

/* ---- 响应式 ---- */
@media (max-width: 1180px) {
  .win-body.has-toc { grid-template-columns: var(--side-w) minmax(0, 1fr); }
  .note-toc { display: none; }
}
@media (max-width: 1000px) {
  :root { --gutter: 16px; }
  .tiles { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
  .band-in { grid-template-columns: 1fr; }
  .win { width: 100%; margin: 0; border-left: 0; border-right: 0; border-radius: 0; box-shadow: none; }
  .win-title { border-radius: 0; }
  .win-body, .win-body.has-toc { display: block; }
  .note-side { position: fixed; z-index: 90; top: 0; left: 0; bottom: 0; height: 100%; width: min(86vw, 340px); transform: translateX(-102%); transition: transform .3s var(--ease); box-shadow: var(--shadow-lg); padding-top: 12px; }
  body.side-open .note-side { transform: none; }
  .side-scrim { position: fixed; inset: 0; z-index: 80; background: rgba(0, 0, 0, .4); }
  body.side-open .side-scrim { display: block; }
  .side-fab { position: fixed; z-index: 60; left: 12px; bottom: 60px; display: inline-flex; align-items: center; min-height: 44px; padding: 0 18px; border-radius: 999px; border: 0; background: var(--a); color: var(--a-on); font-weight: 400; box-shadow: var(--shadow-lg); cursor: pointer; }
}
@media (max-width: 640px) {
  .gl { display: none; }
  .gnav { display: none; }
  .wt-lights { display: none; }
  .tiles { grid-template-columns: 1fr; }
  .f-m, .f-app { display: none; }
  .ws-btn { max-width: 44vw; }
  .ws-i { display: none; }
  .note-main { padding: 22px 16px 32px; }
}
@media print {
  .gbar, .note-side, .note-toc, .side-fab, .win-status, .read-progress, .gfoot { display: none !important; }
  body.v2 { background: #fff; }
  .win { border: 0; width: 100%; box-shadow: none; }
  .win-body, .win-body.has-toc { display: block; }
}


/* ---- 首页「我想做…」任务卡 ---- */
.tasks-band { padding-bottom: 8px; }
.h-sub { margin: -6px 0 14px; color: var(--ink-3); font-size: 14px; }
.tasks { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
.task { display: grid; gap: 2px; padding: 14px 16px; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: inset 0 1px 0 var(--hl-edge), var(--shadow); text-decoration: none; color: var(--ink); transition: transform .15s, border-color .15s, background .15s; }
.task:hover { border-color: var(--a); background: var(--a-soft); transform: translateY(-2px); }
.task-e { font-size: 22px; line-height: 1.2; }
.task-t { font-size: 14.5px; line-height: 1.45; }
.task-h { font-size: 12.5px; color: var(--ink-3); }
@media (max-width: 980px) { .tasks { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
@media (max-width: 680px) { .tasks { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 420px) { .tasks { grid-template-columns: minmax(0, 1fr); } }

/* ---- 课程列表里的难度 / 时长 ---- */
.f-lv { flex: none; font-size: 11.5px; padding: 1px 9px; border-radius: 999px; border: 1px solid transparent; white-space: nowrap; }
.f-lv.lv-1 { color: var(--good); background: var(--good-soft); }
.f-lv.lv-2 { color: var(--warn); background: var(--warn-soft); }
.f-lv.lv-3 { color: var(--a); background: var(--a-soft); }
.f-min { flex: none; font-size: 12px; color: var(--ink-3); white-space: nowrap; min-width: 4.8em; text-align: right; }
@media (max-width: 560px) { .f-min { display: none; } }