/* ==========================================================================
   Microsoft Lab — 「办公室练习簿」
   暖白纸感 + 每个软件一个标签色（像活页夹的分页贴纸）。给完全没学过的人看：
   字大、行距宽、对比够、留白多。改配色只动下面的 :root 和 body[data-app] 两类规则。
   ========================================================================== */

:root {
  /* 纸面 */
  --paper: #FAF8F3;
  --paper-2: #F3F0E8;
  --card: #FFFFFF;
  --ink: #1B2230;
  --ink-2: #465066;
  --ink-3: #69728A;
  --line: #E4DFD3;
  --line-soft: #EEEAE0;
  --shadow: 0 1px 2px rgba(27,34,48,.05), 0 6px 18px rgba(27,34,48,.06);
  --shadow-lg: 0 2px 4px rgba(27,34,48,.06), 0 14px 36px rgba(27,34,48,.10);

  /* 当前软件的标签色（body[data-app] 覆盖） */
  --a: #2F5BD8;
  --a-soft: #E8EEFF;
  --a-on: #FFFFFF;

  /* 状态色 */
  --good: #15803D;  --good-soft: #E3F5E9;
  --bad:  #B42318;  --bad-soft:  #FDE8E6;
  --warn: #9A5B00;  --warn-soft: #FFF1D6;

  --font-head: "Plus Jakarta Sans", "Noto Sans SC", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "Plus Jakarta Sans", system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Consolas, monospace;

  --radius: 14px;
  --radius-sm: 10px;
  --topbar-h: 64px;
  --read-w: 720px;
}

html[data-mode="dark"] {
  --paper: #12151C;
  --paper-2: #181C25;
  --card: #1B2029;
  --ink: #ECEFF5;
  --ink-2: #B9C0D0;
  --ink-3: #8D96AB;
  --line: #2B3240;
  --line-soft: #232937;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 6px 18px rgba(0,0,0,.25);
  --shadow-lg: 0 2px 4px rgba(0,0,0,.35), 0 14px 36px rgba(0,0,0,.4);
  --a: #8FB0FF; --a-soft: #1A2547; --a-on: #0E1420;
  --good: #5FD08A;  --good-soft: #12301F;
  --bad:  #FF8B7E;  --bad-soft:  #3A1A17;
  --warn: #F2B65A;  --warn-soft: #3A2C10;
  color-scheme: dark;
}

/* ---- 每个软件的标签色 ---- */
body[data-app="excel"], [data-app="excel"]      { --a:#157347; --a-soft:#E3F4EA; --a-on:#fff; }
body[data-app="word"], [data-app="word"]        { --a:#2257C4; --a-soft:#E5EDFC; --a-on:#fff; }
body[data-app="powerpoint"], [data-app="powerpoint"] { --a:#C23F12; --a-soft:#FCE9E1; --a-on:#fff; }
body[data-app="outlook"], [data-app="outlook"]  { --a:#0A6CA8; --a-soft:#E1F0FA; --a-on:#fff; }
body[data-app="onenote"], [data-app="onenote"]  { --a:#7A3DB4; --a-soft:#F0E7FA; --a-on:#fff; }
body[data-app="teams"], [data-app="teams"]      { --a:#4A52B8; --a-soft:#E7E8FA; --a-on:#fff; }
body[data-app="onedrive-and-sharepoint"], [data-app="onedrive-and-sharepoint"] { --a:#0B7285; --a-soft:#DFF3F6; --a-on:#fff; }
body[data-app="power-bi"], [data-app="power-bi"] { --a:#946200; --a-soft:#FBF0CF; --a-on:#fff; }

html[data-mode="dark"] body[data-app="excel"], html[data-mode="dark"] [data-app="excel"]      { --a:#5FD08A; --a-soft:#12301F; --a-on:#0B1A12; }
html[data-mode="dark"] body[data-app="word"], html[data-mode="dark"] [data-app="word"]        { --a:#8FB0FF; --a-soft:#16264A; --a-on:#0E1420; }
html[data-mode="dark"] body[data-app="powerpoint"], html[data-mode="dark"] [data-app="powerpoint"] { --a:#FF9A6E; --a-soft:#3A1C10; --a-on:#1E0D06; }
html[data-mode="dark"] body[data-app="outlook"], html[data-mode="dark"] [data-app="outlook"]  { --a:#6CC0F5; --a-soft:#0F2D42; --a-on:#07141F; }
html[data-mode="dark"] body[data-app="onenote"], html[data-mode="dark"] [data-app="onenote"]  { --a:#C9A4F5; --a-soft:#2A1A3C; --a-on:#150C20; }
html[data-mode="dark"] body[data-app="teams"], html[data-mode="dark"] [data-app="teams"]      { --a:#A3AAFF; --a-soft:#1D2145; --a-on:#0C0E22; }
html[data-mode="dark"] body[data-app="onedrive-and-sharepoint"], html[data-mode="dark"] [data-app="onedrive-and-sharepoint"] { --a:#5CCFE0; --a-soft:#0E3038; --a-on:#061A1E; }
html[data-mode="dark"] body[data-app="power-bi"], html[data-mode="dark"] [data-app="power-bi"] { --a:#F2C811; --a-soft:#3A2F08; --a-on:#1E1803; }

/* ---- 基础 ---- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: calc(var(--topbar-h) + 16px); }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { max-width: 100%; }
a { color: var(--a); text-underline-offset: .18em; }
a:hover { text-decoration-thickness: 2px; }
button { font: inherit; color: inherit; }
:focus-visible { outline: 3px solid var(--a); outline-offset: 2px; border-radius: 6px; }
.skip-link { position: absolute; left: -9999px; top: 8px; background: var(--ink); color: var(--paper); padding: 8px 14px; border-radius: 8px; z-index: 200; }
.skip-link:focus { left: 8px; }
.wrap { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 20px; }
.muted { color: var(--ink-3); }

h1, h2, h3, h4 { font-family: var(--font-head); line-height: 1.35; letter-spacing: -.01em; margin: 0; }

/* ---- 按钮 ---- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 48px; padding: 10px 22px; border-radius: 999px;
  font-weight: 700; font-size: 17px; line-height: 1.3; text-decoration: none;
  border: 2px solid transparent; cursor: pointer;
  transition: transform .18s ease, box-shadow .18s ease, background-color .18s ease;
}
.btn-primary { background: var(--a); color: var(--a-on); box-shadow: 0 6px 16px color-mix(in srgb, var(--a) 32%, transparent); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 22px color-mix(in srgb, var(--a) 38%, transparent); text-decoration: none; }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--a); color: var(--a); text-decoration: none; }
.btn-lg { min-height: 56px; padding: 12px 28px; font-size: 18px; }

/* ---- 顶栏 ---- */
.topbar {
  position: sticky; top: 0; z-index: 60; height: var(--topbar-h);
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  backdrop-filter: saturate(1.4) blur(12px); -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--line);
}
.topbar-inner { max-width: 1400px; height: 100%; margin: 0 auto; padding: 0 20px; display: flex; align-items: center; gap: 16px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-family: var(--font-head); font-weight: 700; font-size: 19px; }
.brand b { color: var(--a); font-weight: 800; }
.brand-mark { border-radius: 8px; }
.app-menu { position: relative; }
.app-menu > summary {
  list-style: none; cursor: pointer; display: inline-flex; align-items: center; gap: 6px;
  min-height: 44px; padding: 0 14px; border-radius: 999px; font-weight: 600; font-size: 16px;
}
.app-menu > summary::-webkit-details-marker { display: none; }
.app-menu > summary:hover, .app-menu[open] > summary { background: var(--paper-2); }
.app-menu-panel {
  position: absolute; top: calc(100% + 10px); left: 0; width: min(560px, calc(100vw - 32px));
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow-lg);
  padding: 10px; display: grid; grid-template-columns: 1fr 1fr; gap: 4px;
  animation: pop-in .16s ease;
}
.app-menu-item { display: flex; gap: 10px; align-items: flex-start; padding: 10px 12px; border-radius: var(--radius-sm); text-decoration: none; color: var(--ink); line-height: 1.4; }
.app-menu-item:hover, .app-menu-item.is-active { background: var(--a-soft); }
.app-menu-item b { display: block; font-size: 16px; }
.app-menu-item small { display: block; font-size: 13.5px; color: var(--ink-3); }
.app-dot { flex: none; width: 12px; height: 12px; margin-top: 6px; border-radius: 4px; background: var(--a); }
.topbar-tools { margin-left: auto; display: flex; gap: 6px; align-items: center; }
.tool-btn {
  display: inline-flex; align-items: center; gap: 8px; min-height: 44px; min-width: 44px; padding: 0 12px;
  background: transparent; border: 1px solid transparent; border-radius: 999px; cursor: pointer; justify-content: center;
}
.tool-btn:hover { background: var(--paper-2); }
.tool-btn[aria-pressed="true"] { background: var(--a-soft); border-color: var(--a); color: var(--a); }
.tool-label { font-size: 15px; font-weight: 500; }
.mac-chip { font-size: 16px; line-height: 1; border: 1.5px solid currentColor; border-radius: 6px; padding: 2px 6px; }
.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: 100; display: flex; justify-content: center; align-items: flex-start; padding: 8vh 16px 16px; }
.search-overlay[hidden] { display: none; }
.search-backdrop { position: absolute; inset: 0; background: rgba(15,19,28,.5); backdrop-filter: blur(3px); animation: fade-in .18s ease; }
.search-panel { position: relative; width: min(720px, 100%); max-height: 78vh; display: flex; flex-direction: column; background: var(--card); border-radius: 20px; box-shadow: var(--shadow-lg); overflow: hidden; animation: pop-in .18s ease; }
.search-box { display: flex; gap: 12px; align-items: center; padding: 14px 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: 19px; color: var(--ink); height: 44px; }
.search-esc { border: 1px solid var(--line); background: var(--paper); border-radius: 999px; padding: 4px 14px; min-height: 36px; cursor: pointer; font-size: 14px; }
.search-results { overflow-y: auto; padding: 8px; }
.search-empty { padding: 28px 16px; color: var(--ink-3); text-align: center; margin: 0; }
.search-hit { display: block; padding: 12px 14px; border-radius: var(--radius-sm); text-decoration: none; color: var(--ink); }
.search-hit:hover, .search-hit:focus { background: var(--a-soft); }
.hit-app { display: inline-block; font-size: 12.5px; font-weight: 700; padding: 1px 10px; border-radius: 999px; background: var(--a-soft); color: var(--a); margin-bottom: 4px; }
.hit-title { display: block; font-weight: 700; line-height: 1.5; }
.hit-snippet { display: block; font-size: 15px; color: var(--ink-2); line-height: 1.6; margin-top: 2px; }
.hit-snippet mark, .hit-title mark { background: color-mix(in srgb, #FFD84D 55%, transparent); color: inherit; border-radius: 3px; padding: 0 2px; }

/* ---- 首页 ---- */
.home-hero { padding: 56px 0 40px; background:
  radial-gradient(900px 380px at 85% -10%, var(--a-soft), transparent 70%),
  linear-gradient(var(--paper), var(--paper)); }
.home-hero-grid { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr); gap: 48px; align-items: center; }
.eyebrow { font-size: 15px; font-weight: 700; color: var(--a); letter-spacing: .04em; margin: 0 0 14px; }
.home-hero h1 { font-size: clamp(40px, 6vw, 64px); font-weight: 800; line-height: 1.15; margin: 0 0 20px; }
.lead { font-size: 20px; color: var(--ink-2); max-width: 30em; margin: 0 0 28px; }
.lead b { color: var(--ink); font-family: var(--font-head); }
.home-cta { display: flex; gap: 12px; flex-wrap: wrap; }
.continue-card {
  margin-top: 24px; display: grid; gap: 2px; max-width: 460px; padding: 14px 18px;
  background: var(--card); border: 1px solid var(--line); border-left: 6px solid var(--a);
  border-radius: var(--radius-sm); text-decoration: none; color: var(--ink); box-shadow: var(--shadow); line-height: 1.5;
}
.continue-card[hidden] { display: none; }
.continue-label { font-size: 13px; font-weight: 700; color: var(--a); }
.continue-title { font-weight: 700; }
.continue-app { font-size: 14px; color: var(--ink-3); }

/* 首页右侧：打字的迷你 Excel */
.mock-window { background: var(--card); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow-lg); overflow: hidden; transform: rotate(1.2deg); max-width: 520px; margin-left: auto; }
.mock-bar { display: flex; align-items: center; gap: 6px; padding: 10px 14px; background: #157347; color: #fff; font-size: 14px; }
.mock-bar i { width: 10px; height: 10px; border-radius: 50%; background: rgba(255,255,255,.55); }
.mock-bar span { margin-left: 10px; font-weight: 500; }
.mock-fx { display: flex; gap: 10px; align-items: center; padding: 8px 12px; border-bottom: 1px solid var(--line); font-family: var(--font-mono); font-size: 14px; background: var(--paper); }
.mock-fx-name { padding: 2px 10px; border: 1px solid var(--line); border-radius: 6px; background: var(--card); }
.mock-fx-text .typed { display: inline-block; overflow: hidden; white-space: nowrap; vertical-align: bottom; max-width: 0; border-right: 2px solid #157347; animation: typing 5s steps(12, end) infinite; }
.mock-grid { display: grid; grid-template-columns: 34px 1.3fr 1fr 1fr 1fr; font-size: 15.5px; line-height: 1.2; }
.mock-grid span { padding: 11px 12px; border-right: 1px solid var(--line-soft); border-bottom: 1px solid var(--line-soft); }
.mock-grid .h, .mock-grid .r { background: var(--paper-2); color: var(--ink-3); text-align: center; font-size: 13px; font-weight: 600; }
.mock-grid .strong { font-weight: 700; }
.mock-grid .result { background: #E3F4EA; color: #157347; outline: 2px solid #157347; outline-offset: -2px; text-align: right; animation: result-pop 5s ease infinite; }
html[data-mode="dark"] .mock-grid .result { background: #12301F; color: #5FD08A; outline-color: #5FD08A; }
@keyframes typing { 0%,8% { max-width: 0 } 55%,90% { max-width: 10.5em } 100% { max-width: 0 } }
@keyframes result-pop { 0%,55% { opacity: .15; transform: scale(.92) } 62%,92% { opacity: 1; transform: scale(1) } 100% { opacity: .15 } }

.home-section { padding-top: 56px; padding-bottom: 8px; }
.section-title { font-size: clamp(26px, 3.4vw, 34px); font-weight: 800; margin-bottom: 8px; }
.section-sub { color: var(--ink-2); margin: 0 0 26px; }

.task-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 16px; }
.task-card {
  position: relative; display: grid; gap: 4px; padding: 20px 20px 18px; text-decoration: none; color: var(--ink);
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.task-card::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 6px; background: var(--a); }
.task-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--a); }
.task-emoji { font-size: 30px; line-height: 1.2; }
.task-title { font-family: var(--font-head); font-weight: 700; font-size: 19px; line-height: 1.45; }
.task-hint { color: var(--ink-3); font-size: 15px; line-height: 1.6; }
.task-app { margin-top: 8px; justify-self: start; font-size: 13px; font-weight: 700; color: var(--a); background: var(--a-soft); padding: 1px 10px; border-radius: 999px; }

.app-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 18px; }
.app-card {
  display: grid; grid-template-rows: auto 1fr auto; gap: 14px; padding: 22px; text-decoration: none; color: var(--ink);
  background: var(--card); border: 1px solid var(--line); border-top: 8px solid var(--a); border-radius: var(--radius);
  transition: transform .22s ease, box-shadow .22s ease;
}
.app-card:hover { transform: translateY(-5px) rotate(-.4deg); box-shadow: var(--shadow-lg); }
.app-card-icon { width: 52px; height: 52px; display: grid; place-items: center; border-radius: 14px; background: var(--a-soft); color: var(--a); }
.app-card-icon svg { width: 28px; height: 28px; }
.app-card-body { display: grid; gap: 4px; }
.app-card-body b { font-family: var(--font-head); font-size: 22px; }
.app-card-tag { font-weight: 500; line-height: 1.6; }
.app-card-for { font-size: 15px; color: var(--ink-3); line-height: 1.6; }
.app-card-foot { display: flex; justify-content: space-between; font-size: 15px; font-weight: 700; color: var(--ink-2); padding-top: 12px; border-top: 1px dashed var(--line); }
.app-card-foot .go { color: var(--a); }

.path { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; counter-reset: p; position: relative; }
.path-step { display: flex; gap: 16px; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.path-n { flex: none; width: 46px; height: 46px; border-radius: 50%; display: grid; place-items: center; background: var(--a); color: var(--a-on); font-family: var(--font-head); font-weight: 800; font-size: 20px; }
.path-step h3 { font-size: 20px; margin-bottom: 4px; }
.path-step p { margin: 0; color: var(--ink-2); line-height: 1.7; }

.tips { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 16px; }
.tip { background: var(--paper-2); border-radius: var(--radius); padding: 18px 20px; }
.tip > span { font-size: 26px; }
.tip b { display: block; font-size: 17px; margin: 4px 0 2px; }
.tip p { margin: 0; font-size: 16px; color: var(--ink-2); line-height: 1.7; }

.site-footer { margin-top: 72px; border-top: 1px solid var(--line); background: var(--paper-2); }
.site-footer-inner { max-width: 1120px; margin: 0 auto; padding: 28px 20px; display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; font-size: 15px; color: var(--ink-2); }
.site-footer p { margin: 4px 0 0; line-height: 1.7; }

/* ---- 软件目录页 ---- */
.hub-hero { background: linear-gradient(180deg, var(--a-soft), var(--paper)); padding: 28px 0 40px; border-bottom: 1px solid var(--line); }
.hub-hero-grid { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 36px; align-items: end; margin-top: 18px; }
.hub-icon { width: 64px; height: 64px; display: grid; place-items: center; border-radius: 18px; background: var(--a); color: var(--a-on); margin-bottom: 14px; }
.hub-icon svg { width: 34px; height: 34px; }
.hub-hero h1 { font-size: clamp(36px, 5vw, 52px); font-weight: 800; }
.hub-tag { font-size: 21px; margin: 6px 0 4px; }
.hub-for { color: var(--ink-2); margin: 0 0 20px; }
.hub-cta { display: flex; gap: 12px; flex-wrap: wrap; }
.hub-card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; box-shadow: var(--shadow); }
.hub-card-row { display: flex; justify-content: space-between; padding: 4px 0; font-size: 16px; }
.hub-card-note { margin: 12px 0 0; font-size: 15px; color: var(--ink-3); line-height: 1.7; }
.hub-body { padding-top: 28px; }

.stage-rail { position: sticky; top: var(--topbar-h); z-index: 20; display: flex; gap: 8px; overflow-x: auto; padding: 12px 0; margin-bottom: 20px; background: color-mix(in srgb, var(--paper) 92%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); scrollbar-width: none; }
.stage-rail::-webkit-scrollbar { display: none; }
.stage-rail a { flex: none; display: inline-flex; align-items: center; gap: 8px; min-height: 44px; padding: 0 16px; border-radius: 999px; background: var(--card); border: 1px solid var(--line); text-decoration: none; color: var(--ink); font-weight: 600; font-size: 16px; }
.stage-rail a:hover { border-color: var(--a); }
.stage-rail a.is-current { background: var(--a); border-color: var(--a); color: var(--a-on); }
.stage-rail a.is-current .badge { background: rgba(255,255,255,.22); color: inherit; }

.badge { display: inline-block; font-size: 12.5px; font-weight: 700; padding: 0 9px; border-radius: 999px; line-height: 1.7; margin-right: 8px; vertical-align: middle; font-family: var(--font-body); }
.badge-入门 { background: var(--good-soft); color: var(--good); }
.badge-常用 { background: var(--a-soft); color: var(--a); }
.badge-进阶 { background: var(--warn-soft); color: var(--warn); }

.hub-group { margin: 0 0 32px; padding: 22px; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); }
.hub-group-head { display: flex; justify-content: space-between; gap: 16px; align-items: flex-start; margin-bottom: 14px; }
.hub-group-head h2 { font-size: 24px; }
.hub-group-head p { margin: 2px 0 0; color: var(--ink-2); font-size: 16px; line-height: 1.7; }
.hub-group-count { flex: none; font-size: 15px; color: var(--ink-3); font-weight: 600; padding-top: 6px; }

.hub-cat { border-top: 1px solid var(--line-soft); }
.hub-cat > summary { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 12px; min-height: 52px; padding: 8px 6px; font-weight: 700; }
.hub-cat > summary::-webkit-details-marker { display: none; }
.hub-cat > summary::before { content: "›"; display: inline-block; width: 22px; font-size: 22px; line-height: 1; color: var(--a); transition: transform .18s ease; }
.hub-cat[open] > summary::before { transform: rotate(90deg); }
.hub-cat-name { flex: 1; }
.hub-cat-count { font-size: 14px; font-weight: 500; color: var(--ink-3); }

.lesson-list { list-style: none; margin: 0 0 12px; padding: 0; }
.lesson-row { display: flex; align-items: center; gap: 14px; min-height: 52px; padding: 8px 12px; border-radius: var(--radius-sm); text-decoration: none; color: var(--ink); line-height: 1.55; }
.lesson-row:hover { background: var(--a-soft); }
.lesson-no { flex: none; min-width: 34px; height: 34px; padding: 0 6px; display: grid; place-items: center; border-radius: 10px; background: var(--paper-2); color: var(--ink-2); font-family: var(--font-mono); font-size: 14px; font-weight: 500; }
.lesson-title { flex: 1; }
.lesson-done { display: none; width: 26px; height: 26px; place-items: center; border-radius: 50%; background: var(--good); color: #fff; font-size: 14px; font-weight: 700; }
.lesson-row.is-done .lesson-done { display: grid; }
.lesson-row.is-done .lesson-no { background: var(--good-soft); color: var(--good); }

/* ---- 进度条 ---- */
.sb-progress { display: flex; align-items: center; gap: 10px; }
.sb-progress-bar { flex: 1; height: 8px; border-radius: 999px; background: var(--line); overflow: hidden; }
.sb-progress-bar span { display: block; height: 100%; width: 0; background: var(--a); border-radius: inherit; transition: width .5s cubic-bezier(.2,.8,.2,1); }
.sb-progress-text { font-size: 13.5px; color: var(--ink-3); white-space: nowrap; }
.hub-progress { margin-top: 8px; }

/* ---- 课程页布局 ---- */
.read-progress { position: fixed; left: 0; right: 0; top: var(--topbar-h); height: 4px; z-index: 55; background: transparent; }
.read-progress span { display: block; height: 100%; width: 0; background: var(--a); transition: width .1s linear; }

.note-layout { display: grid; grid-template-columns: 320px minmax(0, 1fr) 230px; gap: 0; max-width: 1400px; margin: 0 auto; align-items: start; }
.note-side { position: sticky; top: var(--topbar-h); height: calc(100vh - var(--topbar-h)); overflow-y: auto; border-right: 1px solid var(--line); background: var(--paper); overscroll-behavior: contain; }
.note-side-inner { padding: 20px 16px 48px; }
.note-main { min-width: 0; overflow-wrap: break-word; padding: 36px 40px 24px; max-width: calc(var(--read-w) + 80px); width: 100%; justify-self: center; }
.note-toc { position: sticky; top: var(--topbar-h); max-height: calc(100vh - var(--topbar-h)); overflow-y: auto; padding: 36px 20px 40px 0; }
.note-toc-inner { border-left: 2px solid var(--line); padding-left: 16px; }
.toc-title { font-size: 13px; font-weight: 700; color: var(--ink-3); letter-spacing: .06em; margin-bottom: 8px; }
.note-toc a { display: block; padding: 4px 0; font-size: 15px; line-height: 1.5; color: var(--ink-2); text-decoration: none; }
.note-toc a:hover { color: var(--a); }
.note-toc a.toc-sub { padding-left: 14px; font-size: 14px; color: var(--ink-3); }
.note-toc a.is-current { color: var(--a); font-weight: 700; }

.sb-home { display: flex; gap: 12px; align-items: center; padding: 12px; margin-bottom: 12px; border-radius: var(--radius); background: var(--a-soft); text-decoration: none; color: var(--ink); line-height: 1.35; }
.sb-home b { display: block; font-size: 17px; }
.sb-home small { color: var(--ink-3); font-size: 13.5px; }
.sb-home-icon { flex: none; width: 42px; height: 42px; display: grid; place-items: center; border-radius: 12px; background: var(--a); color: var(--a-on); }
.sb-home-icon svg { width: 24px; height: 24px; }
.note-side .sb-progress { margin: 0 4px 14px; }

.sb-group { margin: 2px 0; }
.sb-group > summary { list-style: none; cursor: pointer; display: flex; align-items: center; gap: 8px; min-height: 44px; padding: 6px 10px; border-radius: 10px; font-weight: 700; font-size: 15.5px; line-height: 1.4; }
.sb-group > summary::-webkit-details-marker { display: none; }
.sb-group > summary::before { content: "›"; width: 14px; font-size: 18px; line-height: 1; color: var(--ink-3); transition: transform .15s ease; }
.sb-group[open] > summary::before { transform: rotate(90deg); }
.sb-group > summary:hover { background: var(--paper-2); }
.sb-label { flex: 1; }
.sb-count { font-size: 12.5px; font-weight: 500; color: var(--ink-3); background: var(--paper-2); padding: 0 8px; border-radius: 999px; }
.sb-items { padding-left: 14px; }
.sb-group .sb-group .sb-items { padding-left: 8px; }
.sb-depth-0 > summary { font-size: 16px; }
.sb-depth-1 > summary { font-weight: 600; font-size: 15px; }
.sb-item { display: flex; gap: 10px; align-items: flex-start; padding: 7px 10px; border-radius: 10px; text-decoration: none; color: var(--ink-2); font-size: 15px; line-height: 1.5; }
.sb-item:hover { background: var(--paper-2); color: var(--ink); }
.sb-item.is-active { background: var(--a-soft); color: var(--a); font-weight: 700; }
.sb-no { flex: none; min-width: 24px; font-family: var(--font-mono); font-size: 12.5px; color: var(--ink-3); padding-top: 2px; text-align: right; }
.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: 700; }
.sb-flat { padding-left: 0; }

.side-fab, .side-scrim { display: none; }

.crumbs { font-size: 14.5px; color: var(--ink-3); display: flex; flex-wrap: wrap; gap: 4px 6px; align-items: center; line-height: 1.5; }
.crumbs a { color: var(--ink-2); text-decoration: none; }
.crumbs a:hover { color: var(--a); text-decoration: underline; }
.crumbs .current { color: var(--ink); font-weight: 500; }
.note-head { margin: 14px 0 28px; }
.note-kicker { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-bottom: 12px; font-size: 14.5px; }
.app-chip { font-weight: 700; color: var(--a-on); background: var(--a); padding: 1px 12px; border-radius: 999px; }
.kicker-tag { color: var(--a); background: var(--a-soft); padding: 1px 12px; border-radius: 999px; font-weight: 500; }
.kicker-time { color: var(--ink-3); }
.note-title { font-size: clamp(28px, 3.6vw, 38px); font-weight: 800; line-height: 1.3; }

/* ---- 正文 ---- */
.note-body { font-size: 18px; line-height: 1.95; }
.note-body > * { max-width: var(--read-w); }
.note-body p { margin: 0 0 1.1em; }
.note-body h2 { font-size: 28px; font-weight: 800; margin: 1.6em 0 .6em; padding-top: .2em; }
.note-body h3 { font-size: 22px; font-weight: 700; margin: 1.4em 0 .5em; color: var(--ink); }
.note-body h2::before { content: ""; display: inline-block; width: 10px; height: .9em; margin-right: 12px; vertical-align: -.1em; border-radius: 3px; background: var(--a); }
.note-body ul, .note-body ol { margin: 0 0 1.2em; padding-left: 1.5em; }
.note-body li { margin: .35em 0; padding-left: .2em; }
.note-body li::marker { color: var(--a); font-weight: 700; }
.note-body strong { color: var(--a); font-weight: 700; }
.note-body a { font-weight: 500; }
.note-body img { border-radius: var(--radius-sm); border: 1px solid var(--line); }
.note-body hr { border: 0; border-top: 1px solid var(--line); margin: 2em 0; }
.note-body .h3-rule { display: none; }
.note-body .sec-divider { display: none; }
.note-body .sub-divider { display: none; }

.overview { background: var(--a-soft); border-radius: var(--radius); padding: 18px 22px 8px; margin: 0 0 28px; border-left: 6px solid var(--a); }
.overview-label { font-family: var(--font-head); font-weight: 700; font-size: 15px; color: var(--a); margin-bottom: 6px; letter-spacing: .02em; }
.overview ul { margin-bottom: .8em; }
.overview p:last-child { margin-bottom: .8em; }
.note-body .overview strong { color: var(--ink); }

/* 表格 */
.table-scroll { overflow-x: auto; margin: 0 0 1.4em; border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--card); max-width: 100%; }
.note-body table.vocab { border-collapse: collapse; width: 100%; font-size: 16px; line-height: 1.65; min-width: 520px; }
.note-body table.vocab th { text-align: left; background: var(--paper-2); font-weight: 700; padding: 10px 14px; border-bottom: 2px solid var(--line); white-space: nowrap; }
.note-body table.vocab td { padding: 10px 14px; border-bottom: 1px solid var(--line-soft); vertical-align: top; }
.note-body table.vocab tr:last-child td { border-bottom: 0; }
.note-body table.vocab td code { white-space: nowrap; }

/* 提示框 */
.callout { margin: 1.4em 0; padding: 14px 18px; border-radius: var(--radius-sm); border-left: 6px solid; font-size: 17px; line-height: 1.8; }
.callout p { margin: 0; }
.callout-tip  { background: var(--good-soft); border-color: var(--good); }
.callout-warn { background: var(--bad-soft);  border-color: var(--bad); }
.callout-note { background: var(--warn-soft); border-color: var(--warn); }
.note-body blockquote { margin: 1.4em 0; padding: 12px 18px; border-left: 4px solid var(--line); background: var(--paper-2); border-radius: 0 10px 10px 0; }
.note-body blockquote p { margin: 0; }

/* 代码、公式 */
.note-body code { font-family: var(--font-mono); font-size: .88em; padding: .12em .45em; border-radius: 6px; background: var(--paper-2); border: 1px solid var(--line-soft); }
.formula, .code-wrap { position: relative; margin: 1.2em 0; border-radius: var(--radius-sm); background: #14201A; color: #E7F6EC; border: 1px solid #1F3A2B; }
html[data-mode="dark"] .formula, html[data-mode="dark"] .code-wrap { background: #0C1410; }
.formula code { display: block; padding: 16px 84px 16px 18px; background: transparent; border: 0; color: inherit; font-size: 16.5px; line-height: 1.7; white-space: pre-wrap; word-break: break-all; }
.code-wrap pre { margin: 0; padding: 34px 18px 16px; overflow-x: auto; }
.code-wrap code { background: transparent; border: 0; padding: 0; color: inherit; font-size: 15.5px; line-height: 1.7; white-space: pre; }
.code-wrap::before { content: attr(data-lang); position: absolute; left: 18px; top: 8px; font-size: 12px; font-weight: 700; letter-spacing: .08em; color: #7BD3A0; font-family: var(--font-head); }
.copy-btn { position: absolute; right: 10px; top: 10px; min-height: 36px; padding: 0 14px; border-radius: 999px; border: 1px solid rgba(255,255,255,.28); background: rgba(255,255,255,.08); color: #E7F6EC; font-size: 14px; cursor: pointer; }
.copy-btn:hover { background: rgba(255,255,255,.18); }
.copy-btn.is-copied { background: #2BB673; border-color: #2BB673; color: #04170D; font-weight: 700; }
.note-body pre.mermaid { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 18px; overflow-x: auto; max-width: 100%; text-align: center; }

/* 快捷键、菜单路径 */
.keys { display: inline-flex; gap: 4px; align-items: center; vertical-align: baseline; margin: 0 2px; white-space: nowrap; }
.keys i { font-style: normal; color: var(--ink-3); font-size: .85em; }
kbd {
  display: inline-block; min-width: 1.9em; padding: .08em .55em .14em; text-align: center;
  font-family: var(--font-mono); font-size: .85em; font-weight: 500; line-height: 1.45;
  color: var(--ink); background: linear-gradient(var(--card), var(--paper-2));
  border: 1px solid var(--line); border-bottom-width: 3px; border-radius: 8px;
}
.menu-path { display: inline-flex; flex-wrap: wrap; align-items: center; gap: 4px 6px; vertical-align: baseline; line-height: 1.5; }
.menu-path span { background: var(--a-soft); color: var(--a); font-weight: 700; font-size: .9em; padding: 0 .6em; border-radius: 8px; }
.menu-path i { font-style: normal; color: var(--ink-3); font-weight: 700; }

/* 步骤卡 */
ol.steps { list-style: none; counter-reset: step; padding-left: 0; }
ol.steps > li { counter-increment: step; position: relative; padding: 14px 16px 14px 62px; margin: 12px 0; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius-sm); }
ol.steps > li::before { content: counter(step); position: absolute; left: 14px; top: 12px; width: 34px; height: 34px; display: grid; place-items: center; border-radius: 50%; background: var(--a); color: var(--a-on); font-family: var(--font-head); font-weight: 800; font-size: 17px; }
ol.steps > li ul, ol.steps > li ol { margin: .4em 0 0; }

/* 画面提示 */
.shot-note { margin: 1.4em 0; padding: 14px 18px; border: 2px dashed var(--line); border-radius: var(--radius-sm); background: var(--paper-2); }
.shot-label { display: inline-block; font-size: 13px; font-weight: 700; color: var(--ink-3); margin-bottom: 2px; }
.shot-note p { margin: 0; font-size: 16px; color: var(--ink-2); line-height: 1.75; }

/* 学完你会 */
ul.you-will { list-style: none; padding: 0; margin: 0 0 1.4em; display: grid; gap: 8px; }
ul.you-will > li { margin: 0; padding: 0; }
.chk { display: flex; gap: 12px; align-items: flex-start; padding: 12px 16px; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius-sm); cursor: pointer; line-height: 1.7; }
.chk input { flex: none; width: 22px; height: 22px; margin-top: 5px; accent-color: var(--a); }
.chk:has(input:checked) { background: var(--good-soft); border-color: var(--good); }
.chk:has(input:checked) span { text-decoration: line-through; text-decoration-color: color-mix(in srgb, var(--good) 60%, transparent); }

/* 术语 */
.term { border-bottom: 2px dotted var(--a); cursor: help; background: color-mix(in srgb, var(--a-soft) 55%, transparent); border-radius: 3px 3px 0 0; }
.term:hover, .term:focus, .term.is-open { background: var(--a-soft); outline: 0; }
.term-pop {
  position: absolute; z-index: 90; max-width: min(320px, calc(100vw - 24px));
  background: var(--ink); color: var(--paper); padding: 10px 14px; border-radius: 12px;
  font-size: 15.5px; line-height: 1.65; box-shadow: var(--shadow-lg); animation: pop-in .14s ease;
}
.term-pop::after { content: ""; position: absolute; left: var(--arrow-x, 20px); top: 100%; border: 7px solid transparent; border-top-color: var(--ink); }
.term-pop.is-below::after { top: auto; bottom: 100%; border-top-color: transparent; border-bottom-color: var(--ink); }
.term-pop b { display: block; font-size: 13px; opacity: .7; margin-bottom: 2px; }

/* 测验 */
.quiz-section { margin: 48px 0 0; max-width: var(--read-w); }
.quiz-heading { font-size: 26px; font-weight: 800; }
.quiz-lead { color: var(--ink-2); margin: 4px 0 16px; }
.quiz-box { background: var(--card); border: 2px solid var(--a); border-radius: var(--radius); margin: 0 0 14px; overflow: hidden; }
.quiz-box > summary { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 16px 20px; min-height: 60px; background: var(--a); color: var(--a-on); font-weight: 700; font-size: 18px; }
.quiz-box > summary::-webkit-details-marker { display: none; }
.quiz-box[open] > summary { background: var(--a-soft); color: var(--a); border-bottom: 2px solid var(--a); }
.quiz-box-count { margin-left: 12px; font-weight: 500; font-size: 14.5px; opacity: .85; }
.quiz-box-score { font-family: var(--font-head); font-weight: 800; padding: 2px 14px; border-radius: 999px; background: var(--card); color: var(--a); font-size: 15px; }
.quiz-box-body { padding: 20px; }
.quiz-question { margin-bottom: 24px; padding-bottom: 24px; border-bottom: 1px dashed var(--line); }
.quiz-question:last-of-type { border-bottom: 0; margin-bottom: 8px; }
.quiz-question-text { font-weight: 700; line-height: 1.7; margin-bottom: 12px; }
.quiz-options { display: grid; gap: 10px; }
.quiz-option { text-align: left; padding: 12px 16px; min-height: 52px; background: var(--paper); border: 2px solid var(--line); border-radius: var(--radius-sm); cursor: pointer; line-height: 1.6; transition: border-color .15s ease, background-color .15s ease; }
.quiz-option:hover:not(:disabled) { border-color: var(--a); }
.quiz-option.is-selected { border-color: var(--a); background: var(--a-soft); }
.quiz-option.is-correct { border-color: var(--good); background: var(--good-soft); font-weight: 700; }
.quiz-option.is-wrong { border-color: var(--bad); background: var(--bad-soft); }
.quiz-option:disabled { cursor: default; }
.quiz-fill-input { width: 100%; min-height: 52px; padding: 10px 16px; font: inherit; background: var(--paper); border: 2px solid var(--line); border-radius: var(--radius-sm); color: var(--ink); }
.quiz-fill-input:focus { outline: 0; border-color: var(--a); }
.quiz-fill-input.is-correct { border-color: var(--good); background: var(--good-soft); }
.quiz-fill-input.is-wrong { border-color: var(--bad); background: var(--bad-soft); }
.quiz-correct-answer { margin-top: 8px; color: var(--good); font-weight: 700; }
.quiz-reorder-picked { min-height: 56px; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; padding: 8px; border: 2px dashed var(--line); border-radius: var(--radius-sm); margin-bottom: 10px; }
.quiz-reorder-picked.is-correct { border-style: solid; border-color: var(--good); background: var(--good-soft); }
.quiz-reorder-picked.is-wrong { border-style: solid; border-color: var(--bad); background: var(--bad-soft); }
.quiz-reorder-hint { color: var(--ink-3); font-size: 15px; }
.quiz-reorder-pool { display: flex; flex-wrap: wrap; gap: 8px; }
.quiz-reorder-chip { min-height: 44px; padding: 6px 14px; border: 2px solid var(--line); border-radius: 10px; background: var(--paper); cursor: pointer; }
.quiz-reorder-chip.is-picked { border-color: var(--a); background: var(--a-soft); }
.quiz-explanation { margin-top: 12px; padding: 12px 16px; border-radius: var(--radius-sm); background: var(--paper-2); border-left: 5px solid var(--a); font-size: 16.5px; line-height: 1.75; }
.quiz-actions { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; margin-top: 8px; }
.quiz-submit, .quiz-retry { min-height: 48px; padding: 0 24px; border-radius: 999px; border: 0; background: var(--a); color: var(--a-on); font-weight: 700; cursor: pointer; }
.quiz-retry { background: var(--paper-2); color: var(--ink); border: 1px solid var(--line); }
.quiz-submit:disabled { opacity: .45; cursor: not-allowed; }
.quiz-page-nav { display: flex; gap: 6px; flex-wrap: wrap; margin: 6px 0 16px; }
.quiz-page-btn { min-width: 44px; min-height: 44px; border-radius: 10px; border: 1px solid var(--line); background: var(--paper); cursor: pointer; font-weight: 700; }
.quiz-page-btn.is-active { background: var(--a); border-color: var(--a); color: var(--a-on); }
.quiz-page-btn:disabled { opacity: .4; cursor: default; }

/* 学完按钮 + 上下课 */
.done-bar { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin: 48px 0 20px; padding: 18px 20px; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); max-width: var(--read-w); }
.done-btn { display: inline-flex; align-items: center; gap: 12px; min-height: 52px; padding: 0 20px; border-radius: 999px; background: var(--paper); border: 2px solid var(--line); cursor: pointer; font-weight: 700; transition: all .2s ease; }
.done-btn:hover { border-color: var(--good); }
.done-box { width: 24px; height: 24px; border-radius: 8px; border: 2px solid var(--ink-3); display: grid; place-items: center; transition: all .2s ease; }
.done-btn[aria-pressed="true"] { background: var(--good-soft); border-color: var(--good); color: var(--good); }
.done-btn[aria-pressed="true"] .done-box { background: var(--good); border-color: var(--good); }
.done-btn[aria-pressed="true"] .done-box::after { content: "✓"; color: #fff; font-size: 15px; font-weight: 800; line-height: 1; }
.done-hint { font-size: 14px; color: var(--ink-3); }

.nav-footer { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 8px; max-width: var(--read-w); }
.nav-footer a { display: grid; gap: 2px; padding: 16px 18px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--card); text-decoration: none; color: var(--ink); line-height: 1.5; transition: transform .18s ease, border-color .18s ease, box-shadow .18s ease; }
.nav-footer a:hover { border-color: var(--a); transform: translateY(-3px); box-shadow: var(--shadow); }
.nav-footer .dir { font-size: 14px; font-weight: 700; color: var(--a); }
.nav-footer .t { font-weight: 700; }
.nav-footer .nav-next { text-align: right; }
.nav-footer .disabled { opacity: .5; pointer-events: none; }

/* ---- 滚动出现 ---- */
.js [data-reveal], .js .note-body > *.reveal-ready { opacity: 0; transform: translateY(16px); transition: opacity .55s ease, transform .55s cubic-bezier(.2,.8,.2,1); }
.js [data-reveal].is-in, .js .note-body > *.reveal-ready.is-in { opacity: 1; transform: none; }

/* ---- 页面转场（View Transitions API：Chrome/Edge 126+、Safari 18.2+；其他浏览器正常跳转） ---- */
@media (prefers-reduced-motion: no-preference) {
  @view-transition { navigation: auto; }
  ::view-transition-old(root) { animation: .22s ease both vt-out; }
  ::view-transition-new(root) { animation: .32s cubic-bezier(.2,.8,.2,1) both vt-in; }
  html:active-view-transition-type(forward)::view-transition-old(root) { animation: .26s ease both vt-slide-out-left; }
  html:active-view-transition-type(forward)::view-transition-new(root) { animation: .34s cubic-bezier(.2,.8,.2,1) both vt-slide-in-right; }
  html:active-view-transition-type(back)::view-transition-old(root) { animation: .26s ease both vt-slide-out-right; }
  html:active-view-transition-type(back)::view-transition-new(root) { animation: .34s cubic-bezier(.2,.8,.2,1) both vt-slide-in-left; }
  html:active-view-transition-type(zoom)::view-transition-old(root) { animation: .3s ease both vt-zoom-out; }
  html:active-view-transition-type(zoom)::view-transition-new(root) { animation: .4s cubic-bezier(.2,.8,.2,1) both vt-circle; }
  .topbar { view-transition-name: topbar; }
  ::view-transition-group(topbar) { animation-duration: 0s; }
}
@keyframes vt-out { to { opacity: 0; } }
@keyframes vt-in { from { opacity: 0; transform: translateY(10px); } }
@keyframes vt-slide-out-left { to { opacity: 0; transform: translateX(-48px); } }
@keyframes vt-slide-in-right { from { opacity: 0; transform: translateX(48px); } }
@keyframes vt-slide-out-right { to { opacity: 0; transform: translateX(48px); } }
@keyframes vt-slide-in-left { from { opacity: 0; transform: translateX(-48px); } }
@keyframes vt-zoom-out { to { opacity: 0; transform: scale(.96); } }
@keyframes vt-circle { from { clip-path: circle(0% at 50% 40%); } to { clip-path: circle(150% at 50% 40%); } }
@keyframes fade-in { from { opacity: 0; } }
@keyframes pop-in { from { opacity: 0; transform: translateY(-6px) scale(.98); } }

/* ---- 响应式 ---- */
@media (max-width: 1180px) {
  .note-layout { grid-template-columns: 300px minmax(0, 1fr); }
  .note-toc { display: none; }
}
@media (max-width: 900px) {
  body { font-size: 17.5px; }
  .home-hero-grid, .hub-hero-grid { grid-template-columns: 1fr; gap: 28px; }
  .mock-window { margin: 0 auto; transform: none; }
  .path { grid-template-columns: 1fr; }
  .note-layout { display: block; }
  .note-main { padding: 24px 18px 24px; margin: 0 auto; }
  .note-side {
    position: fixed; z-index: 80; top: 0; left: 0; bottom: 0; height: 100%; width: min(88vw, 360px);
    transform: translateX(-102%); transition: transform .28s cubic-bezier(.2,.8,.2,1);
    box-shadow: var(--shadow-lg); padding-top: var(--topbar-h);
  }
  body.side-open .note-side { transform: none; }
  .side-scrim { position: fixed; inset: 0; z-index: 70; background: rgba(15,19,28,.5); }
  body.side-open .side-scrim { display: block; }
  .side-fab {
    position: fixed; z-index: 65; left: 14px; bottom: 16px; display: inline-flex; align-items: center; gap: 8px;
    min-height: 52px; padding: 0 20px; border-radius: 999px; border: 0; cursor: pointer;
    background: var(--a); color: var(--a-on); font-weight: 700; box-shadow: var(--shadow-lg);
  }
}
@media (max-width: 640px) {
  .tool-label { display: none; }
  .topbar-inner { gap: 6px; padding: 0 12px; }
  .brand-text { font-size: 17px; }
  .app-menu-panel { grid-template-columns: 1fr; position: fixed; left: 12px; right: 12px; top: calc(var(--topbar-h) + 6px); width: auto; }
  .nav-footer { grid-template-columns: 1fr; }
  .nav-footer .nav-next { text-align: left; }
  .note-body h2 { font-size: 24px; }
  .note-body h3 { font-size: 20px; }
  .hub-group { padding: 16px; }
  .home-hero { padding-top: 32px; }
  .btn-lg { width: 100%; }
  ol.steps > li { padding-left: 56px; }
}
@media (hover: none) {
  .task-card:hover, .app-card:hover, .nav-footer a:hover { transform: none; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; scroll-behavior: auto !important; }
  .js [data-reveal], .js .note-body > *.reveal-ready { opacity: 1; transform: none; }
  .mock-fx-text .typed { max-width: 10.5em; }
}
@media print {
  .topbar, .note-side, .note-toc, .side-fab, .read-progress, .done-bar, .nav-footer, .search-overlay, .site-footer { display: none !important; }
  body { background: #fff; font-size: 12pt; }
  .note-layout { display: block; }
}