/* =========================================================
   Vpin AI 落地計劃書 — styles.css
   顧問 / 商業文件式;白底、深藍灰、三軸 accent
   ========================================================= */

/* --- Fonts ---------------------------------------------------------------
   Production deploy: replace these @import with self-hosted @font-face
   blocks pointing to /fonts/*.woff2 (see README.md).
   ------------------------------------------------------------------------ */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Noto+Sans+TC:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* =========================================================
   Design tokens
   ========================================================= */
:root {
  /* Brand */
  --c-ink:        #1F3A5F;   /* primary heading colour — deep blue-grey */
  --c-ink-soft:   #34547a;
  --c-body:       #2a3540;
  --c-muted:      #6b7785;
  --c-faint:      #97a1ad;

  --c-bg:         #ffffff;
  --c-surface:    #f7f8fa;
  --c-surface-2:  #eef1f5;
  --c-line:       #e3e7ec;
  --c-line-soft:  #eef1f5;

  /* Three axes */
  --c-product:    #4A90E2;   /* 蒼藍 */
  --c-product-bg: #eaf3fc;
  --c-product-bd: #b9d6f4;

  --c-marketing:    #F39C12;   /* 暖橙 */
  --c-marketing-bg: #fdf1dc;
  --c-marketing-bd: #f6cf86;

  --c-ops:        #7CB342;   /* 草綠 */
  --c-ops-bg:     #eaf4dd;
  --c-ops-bd:     #c2dfa0;

  /* RACI */
  --c-raci-r:     #7CB342;
  --c-raci-r-bg:  #eaf4dd;
  --c-raci-a:     #1F3A5F;
  --c-raci-a-bg:  #eaf0f7;
  --c-raci-c:     #b6bec8;
  --c-raci-c-bg:  #f1f3f6;
  --c-raci-i:     #97a1ad;

  /* Type */
  --f-sans-zh: 'Noto Sans TC', 'PingFang TC', 'Microsoft JhengHei', system-ui, sans-serif;
  --f-sans-en: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --f-mono:    'JetBrains Mono', 'SF Mono', Menlo, Consolas, monospace;
  --f-text:    var(--f-sans-en), var(--f-sans-zh);

  /* Spacing rhythm */
  --gap-1: 4px;
  --gap-2: 8px;
  --gap-3: 12px;
  --gap-4: 16px;
  --gap-5: 24px;
  --gap-6: 32px;
  --gap-7: 48px;
  --gap-8: 64px;

  --radius-sm: 4px;
  --radius:    8px;
  --radius-lg: 12px;

  --shadow-card: 0 1px 2px rgba(31, 58, 95, 0.04), 0 1px 6px rgba(31, 58, 95, 0.05);

  /* Layout */
  --sidebar-w:    280px;
  --content-w:    960px;
  --header-h:     64px;
}

/* =========================================================
   Reset / base
   ========================================================= */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; overflow-x: clip; }
body { overflow-x: clip; }

body {
  margin: 0;
  font-family: var(--f-text);
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-body);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  text-wrap: pretty;
  font-feature-settings: "tnum" 1, "cv11" 1;
}

a { color: var(--c-product); text-decoration: none; }
a:hover { text-decoration: underline; }

code, kbd, samp, pre {
  font-family: var(--f-mono);
  font-size: 0.92em;
}

/* =========================================================
   Site header (fixed)
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: var(--gap-4);
  padding: 0 24px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--c-line);
}

.site-header__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--f-sans-zh);
  font-weight: 600;
  color: var(--c-ink);
  font-size: 15px;
  letter-spacing: 0.01em;
  min-width: 0;
}

.site-header__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px; height: 26px;
  border-radius: 6px;
  background: linear-gradient(135deg, var(--c-ink) 0%, #34547a 100%);
  color: #fff;
  font-family: var(--f-sans-en);
  font-weight: 700;
  font-size: 13px;
  flex: none;
}

.site-header__title-zh {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.site-header__title--short { display: none; }
@media (max-width: 480px) {
  .site-header__title--full  { display: none; }
  .site-header__title--short { display: inline; }
}

.site-header__meta {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--gap-4);
  font-family: var(--f-sans-en);
  font-size: 12px;
  color: var(--c-muted);
}

.site-header__meta b {
  font-weight: 600;
  color: var(--c-ink);
  font-feature-settings: "tnum" 1;
}

.site-header__pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid var(--c-line);
  border-radius: 999px;
  background: var(--c-surface);
  color: var(--c-ink);
  font-weight: 500;
}

.site-header__pill::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--c-ops);
  box-shadow: 0 0 0 3px rgba(124, 179, 66, 0.18);
}

/* Hamburger */
.hamburger {
  display: none;
  width: 36px; height: 36px;
  border: 1px solid var(--c-line);
  background: #fff;
  border-radius: 8px;
  cursor: pointer;
  padding: 0;
  align-items: center;
  justify-content: center;
}
.hamburger:hover { background: var(--c-surface); }
.hamburger__bars { display: block; width: 16px; height: 10px; position: relative; }
.hamburger__bars::before,
.hamburger__bars::after,
.hamburger__bars span {
  content: "";
  position: absolute;
  left: 0; right: 0;
  height: 1.8px;
  background: var(--c-ink);
  border-radius: 2px;
  transition: transform .2s ease, opacity .2s ease;
}
.hamburger__bars::before { top: 0; }
.hamburger__bars span    { top: 50%; transform: translateY(-50%); display: block; }
.hamburger__bars::after  { bottom: 0; }
.hamburger[aria-expanded="true"] .hamburger__bars::before { transform: translateY(4px) rotate(45deg); }
.hamburger[aria-expanded="true"] .hamburger__bars::after  { transform: translateY(-4px) rotate(-45deg); }
.hamburger[aria-expanded="true"] .hamburger__bars span    { opacity: 0; }

/* =========================================================
   Layout: sidebar + content
   ========================================================= */
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  align-items: start;
  min-width: 0;
}
.layout > * { min-width: 0; }

.sidebar {
  position: sticky;
  top: var(--header-h);
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  padding: 32px 20px 64px 24px;
  border-right: 1px solid var(--c-line);
  background: var(--c-bg);
}

.sidebar__label {
  font-family: var(--f-sans-en);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-faint);
  margin-bottom: var(--gap-3);
}

.toc { list-style: none; margin: 0; padding: 0; }
.toc li { margin: 0; }
.toc a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 6px 10px 6px 10px;
  border-radius: 6px;
  color: var(--c-body);
  font-size: 13.5px;
  line-height: 1.45;
  border-left: 2px solid transparent;
  transition: background .15s ease, color .15s ease, border-color .15s ease;
}
.toc a:hover { background: var(--c-surface); text-decoration: none; }
.toc a.is-active {
  color: var(--c-ink);
  background: var(--c-surface);
  border-left-color: var(--c-ink);
  font-weight: 600;
}
.toc__num {
  font-family: var(--f-sans-en);
  font-size: 11.5px;
  color: var(--c-faint);
  font-feature-settings: "tnum" 1;
  flex: none;
  width: 28px;
}
.toc a.is-active .toc__num { color: var(--c-ink); }

.toc--lvl-2 a { padding-left: 26px; font-size: 13px; color: var(--c-muted); }
.toc--lvl-2 { margin: 2px 0 6px; }

.toc__group { margin-bottom: 6px; }

/* Content */
.content {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 48px 56px 96px;
  width: 100%;
  min-width: 0;
  overflow-x: clip;
}
.doc { min-width: 0; }
.doc > * { max-width: 100%; }

/* =========================================================
   Typography for the document
   ========================================================= */
.doc {
  font-family: var(--f-text);
}

.doc h1, .doc h2, .doc h3, .doc h4 {
  font-family: var(--f-sans-en), var(--f-sans-zh);
  color: var(--c-ink);
  line-height: 1.3;
  letter-spacing: -0.005em;
  text-wrap: balance;
  scroll-margin-top: calc(var(--header-h) + 16px);
  position: relative;
}

.doc h1 {
  font-size: 36px;
  font-weight: 700;
  margin: 0 0 8px;
  letter-spacing: -0.01em;
}

.doc h2 {
  font-size: 24px;
  font-weight: 700;
  margin: 56px 0 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--c-line);
}

.doc h3 {
  font-size: 19px;
  font-weight: 600;
  margin: 40px 0 12px;
  color: var(--c-ink);
}

.doc h4 {
  font-size: 16px;
  font-weight: 600;
  margin: 24px 0 8px;
  color: var(--c-ink);
}

.doc h2 .sec-num,
.doc h3 .sec-num {
  color: var(--c-faint);
  font-family: var(--f-sans-en);
  font-weight: 500;
  margin-right: 10px;
  font-feature-settings: "tnum" 1;
}

/* Hash anchor on hover */
.doc h2 .anchor,
.doc h3 .anchor {
  position: absolute;
  left: -22px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--c-faint);
  opacity: 0;
  font-weight: 400;
  font-family: var(--f-sans-en);
  text-decoration: none;
  transition: opacity .15s ease;
  font-size: 0.85em;
}
.doc h2:hover .anchor,
.doc h3:hover .anchor { opacity: 1; }

.doc p {
  margin: 0 0 14px;
}

.doc strong { color: var(--c-ink); font-weight: 600; }

.doc ul, .doc ol {
  margin: 6px 0 18px;
  padding-left: 22px;
}
.doc li {
  margin: 4px 0;
}
.doc li::marker { color: var(--c-faint); }

/* Lead */
.lead {
  font-size: 17px;
  color: var(--c-ink-soft);
  margin: 0 0 24px;
  max-width: 64ch;
}

/* Doc meta block under H1 */
.doc-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  font-family: var(--f-sans-en);
  font-size: 12.5px;
  color: var(--c-muted);
  border-top: 1px solid var(--c-line);
  border-bottom: 1px solid var(--c-line);
  padding: 12px 0;
  margin: 16px 0 28px;
}
.doc-meta b { color: var(--c-ink); font-weight: 600; }
.doc-meta .dot { color: var(--c-faint); }

/* Blockquote / note */
.doc blockquote {
  margin: 16px 0 24px;
  padding: 14px 18px;
  border-left: 3px solid var(--c-ink);
  background: var(--c-surface);
  color: var(--c-ink-soft);
  border-radius: 0 6px 6px 0;
  font-size: 14.5px;
}
.doc blockquote p { margin: 4px 0; }

/* "[會變]" tag */
.tag-changes {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: var(--c-surface-2);
  color: var(--c-muted);
  border: 1px solid var(--c-line);
  padding: 2px 8px 2px 7px;
  border-radius: 999px;
  font-style: italic;
  font-size: 12.5px;
  font-family: var(--f-sans-zh);
  vertical-align: 2px;
  margin-left: 6px;
  letter-spacing: 0.02em;
}
.tag-changes::before {
  content: "";
  width: 12px; height: 12px;
  border-radius: 50%;
  background: var(--c-faint);
  color: #fff;
  font-size: 9px;
  font-family: var(--f-sans-en);
  font-style: normal;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background-image: radial-gradient(circle at 50% 38%, #fff 1.4px, transparent 1.5px),
                    radial-gradient(circle at 50% 64%, #fff 0.7px, transparent 0.8px);
  background-color: var(--c-faint);
}

/* =========================================================
   Tables
   ========================================================= */
.table-wrap {
  margin: 18px 0 28px;
  overflow-x: auto;
  border: 1px solid var(--c-line);
  border-radius: 8px;
  background: #fff;
}

.doc table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.doc thead th {
  background: var(--c-ink);
  color: #fff;
  font-weight: 600;
  text-align: left;
  padding: 10px 14px;
  font-size: 13px;
  letter-spacing: 0.01em;
  border-right: 1px solid rgba(255,255,255,0.08);
  white-space: nowrap;
}
.doc thead th:last-child { border-right: none; }

.doc tbody td {
  padding: 11px 14px;
  border-top: 1px solid var(--c-line);
  border-right: 1px solid var(--c-line-soft);
  vertical-align: top;
  line-height: 1.6;
}
.doc tbody td:last-child { border-right: none; }
.doc tbody tr:nth-child(even) td { background: #fafbfc; }
.doc tbody tr:hover td { background: #f3f6fa; }

/* RACI table */
.raci-wrap {
  position: relative;
  margin: 18px 0 12px;
  border: 1px solid var(--c-line);
  border-radius: 8px;
  overflow: auto;
  max-height: 540px;
}
.raci {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  font-size: 13.5px;
  min-width: 720px;
}
.raci thead th {
  position: sticky;
  top: 0;
  background: var(--c-ink);
  color: #fff;
  font-weight: 600;
  padding: 10px 12px;
  text-align: center;
  font-size: 12.5px;
  z-index: 2;
  border-right: 1px solid rgba(255,255,255,0.08);
}
.raci thead th:first-child {
  text-align: left;
  z-index: 2;
  background: var(--c-ink);
  min-width: 200px;
}
.raci tbody td {
  padding: 10px 12px;
  border-top: 1px solid var(--c-line);
  text-align: center;
  font-family: var(--f-sans-en);
  font-weight: 600;
  font-size: 13px;
  color: var(--c-body);
  border-right: 1px solid var(--c-line-soft);
}
.raci tbody td:first-child {
  text-align: left;
  font-family: var(--f-text);
  font-weight: 500;
  color: var(--c-ink);
  background: #fff;
}
.raci tbody tr:nth-child(even) td:first-child { background: #fafbfc; }

.raci-cell { display: inline-flex; align-items: center; justify-content: center; width: 26px; height: 26px; border-radius: 6px; font-size: 12px; font-weight: 700; line-height: 1; }
.raci-cell--R  { background: var(--c-raci-r); color: #fff; }
.raci-cell--RA { background: var(--c-raci-r); color: #fff; box-shadow: inset 0 0 0 2px var(--c-raci-a); }
.raci-cell--A  { background: var(--c-raci-a-bg); color: var(--c-raci-a); box-shadow: inset 0 0 0 2px var(--c-raci-a); }
.raci-cell--C  { background: var(--c-raci-c-bg); color: #6b7785; }
.raci-cell--I  { background: #fff; color: var(--c-raci-i); border: 1.5px dashed var(--c-raci-i); }
.raci-cell--empty { color: var(--c-faint); font-weight: 400; }

.raci-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 22px;
  font-size: 12.5px;
  margin: 4px 2px 24px;
  font-family: var(--f-sans-en);
  color: var(--c-muted);
}
.raci-legend > span { display: inline-flex; align-items: center; gap: 8px; }
.raci-legend b { color: var(--c-ink); }

/* =========================================================
   ROI formula box
   ========================================================= */
.formula {
  margin: 16px 0 22px;
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  border-left: 3px solid var(--c-product);
  border-radius: 8px;
  padding: 18px 22px;
  font-family: var(--f-mono);
  font-size: 13px;
  line-height: 1.8;
  color: var(--c-ink-soft);
  overflow-x: auto;
  white-space: pre;
}
.formula b { color: var(--c-ink); font-weight: 700; }
.formula .c-muted { color: var(--c-faint); }
.formula .c-prod { color: var(--c-product); }
.formula .c-mkt  { color: var(--c-marketing); }
.formula .c-ops  { color: var(--c-ops); }

/* =========================================================
   Diagram 1: 三軸 month 6 終態 matrix (3 cards)
   ========================================================= */
.axis-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin: 18px 0 24px;
}
.axis-card {
  border: 1px solid var(--c-line);
  border-top: 3px solid var(--axis-c, var(--c-ink));
  border-radius: 10px;
  padding: 20px 20px 22px;
  background: #fff;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-card);
}
.axis-card--product   { --axis-c: var(--c-product); }
.axis-card--marketing { --axis-c: var(--c-marketing); }
.axis-card--ops       { --axis-c: var(--c-ops); }

.axis-card__kicker-row {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 12px;
}
.axis-card__head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 10px;
}
.axis-card__head .axis-card__title { margin: 0; line-height: 1; display: flex; align-items: center; }
.axis-card__icon {
  width: 36px; height: 36px;
  border-radius: 8px;
  background: var(--axis-bg);
  color: var(--axis-c);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: none;
}
.axis-card--product   .axis-card__icon { background: var(--c-product-bg); color: var(--c-product); }
.axis-card--marketing .axis-card__icon { background: var(--c-marketing-bg); color: var(--c-marketing); }
.axis-card--ops       .axis-card__icon { background: var(--c-ops-bg); color: var(--c-ops); }

.axis-card__kicker {
  font-family: var(--f-sans-en);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-faint);
  font-weight: 600;
}
.axis-card__title {
  font-family: var(--f-sans-zh);
  font-size: 18px;
  font-weight: 700;
  color: var(--c-ink);
  margin: 0;
  line-height: 1.25;
}
.axis-card__sub {
  color: var(--c-muted);
  font-size: 13px;
  margin: 0 0 14px;
}
.axis-card ul {
  list-style: none;
  padding: 0;
  margin: 4px 0 0;
}
.axis-card li {
  position: relative;
  padding: 8px 0 8px 22px;
  border-top: 1px solid var(--c-line-soft);
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--c-body);
}
.axis-card li:first-child { border-top: none; }
.axis-card li::before {
  content: "";
  position: absolute;
  left: 4px; top: 16px;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--axis-c, var(--c-ink));
}
.axis-card--product   li::before { background: var(--c-product); }
.axis-card--marketing li::before { background: var(--c-marketing); }
.axis-card--ops       li::before { background: var(--c-ops); }

/* =========================================================
   Diagram 2: 三柱流程 (度量 → Harness → retro)
   ========================================================= */
.pillars {
  display: grid;
  grid-template-columns: 1fr 32px 1fr 32px 1fr;
  align-items: stretch;
  gap: 0;
  margin: 16px 0 28px;
}
.pillar {
  border: 1px solid var(--c-line);
  border-radius: 10px;
  padding: 18px 18px 18px;
  background: #fff;
  display: flex;
  flex-direction: column;
  gap: 6px;
  box-shadow: var(--shadow-card);
}
.pillar__step {
  font-family: var(--f-sans-en);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--c-faint);
}
.pillar__title {
  font-family: var(--f-sans-zh);
  font-weight: 700;
  font-size: 16px;
  color: var(--c-ink);
  margin: 0 0 4px;
}
.pillar__sub  { color: var(--c-muted); font-size: 13px; margin: 0 0 8px; line-height: 1.5; }
.pillar ul    { list-style: none; padding: 0; margin: 4px 0 0; }
.pillar li    {
  font-size: 12.5px;
  color: var(--c-body);
  padding: 4px 0 4px 16px;
  position: relative;
  line-height: 1.5;
}
.pillar li::before {
  content: ""; position: absolute; left: 2px; top: 11px;
  width: 8px; height: 1.5px; background: var(--c-faint);
}
.pillar__arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--c-faint);
}
.pillar__arrow svg { width: 100%; max-width: 32px; }

/* =========================================================
   Diagram 3: 目標階層 pyramid + retro loop
   ========================================================= */
.goal-hier {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 220px;
  gap: 24px;
  align-items: center;
  margin: 16px 0 28px;
}
.pyramid {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.pyramid__layer {
  position: relative;
  border: 1px solid var(--c-line);
  background: #fff;
  border-radius: 8px;
  padding: 14px 22px;
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: 18px;
  align-items: center;
  box-shadow: var(--shadow-card);
}
.pyramid__layer--1 { width: 100%; border-top: 3px solid var(--c-ink); }
.pyramid__layer--2 { width: 80%;  border-top: 3px solid var(--c-product); }
.pyramid__layer--3 { width: 60%;  border-top: 3px solid var(--c-ops); }
.pyramid__name {
  font-family: var(--f-sans-zh);
  font-weight: 700;
  color: var(--c-ink);
  font-size: 15px;
}
.pyramid__name small {
  display: block;
  font-weight: 400;
  font-size: 12px;
  color: var(--c-muted);
  margin-top: 2px;
  font-family: var(--f-sans-en);
}
.pyramid__time {
  font-family: var(--f-mono);
  font-size: 12px;
  color: var(--c-ink-soft);
  background: var(--c-surface);
  padding: 3px 8px;
  border-radius: 4px;
  border: 1px solid var(--c-line);
  white-space: nowrap;
}
.pyramid__owner {
  font-size: 12px;
  color: var(--c-muted);
  white-space: nowrap;
}
.pyramid__owner b { color: var(--c-ink); }

.retro-loop {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 18px 12px;
  border: 1px dashed var(--c-line);
  border-radius: 12px;
  background: var(--c-surface);
}
.retro-loop__label {
  font-size: 12px;
  color: var(--c-faint);
  font-family: var(--f-sans-en);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 600;
}
.retro-loop__title {
  font-family: var(--f-sans-zh);
  color: var(--c-ink);
  font-weight: 700;
  font-size: 14px;
  text-align: center;
}
.retro-loop svg { width: 100px; height: 100px; }

/* =========================================================
   Diagram 4: 6-month timeline + review nodes
   ========================================================= */
.timeline {
  margin: 18px 0 28px;
  padding: 26px 18px 22px;
  border: 1px solid var(--c-line);
  border-radius: 10px;
  background: #fff;
}
.timeline__axis {
  position: relative;
  display: grid;
  grid-template-columns: repeat(7, 1fr); /* 5/15 + 6 monthly ticks */
  margin: 0 0 16px;
  padding-top: 56px;
}
.timeline__axis::before {
  content: "";
  position: absolute;
  left: 4%; right: 4%;
  top: 56px;
  height: 2px;
  background: var(--c-line);
  border-radius: 2px;
}
.timeline__tick {
  position: relative;
  text-align: center;
}
.timeline__tick::after {
  content: "";
  position: absolute;
  left: 50%; top: 52px;
  width: 10px; height: 10px;
  background: #fff;
  border: 2px solid var(--c-faint);
  border-radius: 50%;
  transform: translate(-50%, 0);
}
.timeline__tick--start::after,
.timeline__tick--end::after {
  background: var(--c-ink); border-color: var(--c-ink);
  width: 12px; height: 12px;
}
.timeline__tick--review::after {
  background: var(--c-marketing);
  border-color: var(--c-marketing);
  width: 14px; height: 14px;
  box-shadow: 0 0 0 3px var(--c-marketing-bg);
}
.timeline__date {
  font-family: var(--f-mono);
  font-size: 11.5px;
  color: var(--c-muted);
  display: block;
  margin-bottom: 4px;
}
.timeline__label {
  font-family: var(--f-sans-zh);
  font-size: 12.5px;
  font-weight: 600;
  color: var(--c-ink);
  position: absolute;
  bottom: 56px;
  left: 50%;
  transform: translateX(-50%);
  white-space: nowrap;
}
.timeline__label small {
  display: block;
  font-weight: 400;
  color: var(--c-muted);
  font-size: 11px;
  margin-top: 1px;
  font-family: var(--f-sans-en);
}

.timeline__lanes {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 8px;
}
.lane {
  display: grid;
  grid-template-columns: 100px 1fr;
  align-items: center;
  gap: 12px;
}
.lane__label {
  font-family: var(--f-sans-zh);
  font-size: 13px;
  font-weight: 600;
}
.lane__bar {
  height: 24px;
  border-radius: 4px;
  position: relative;
  display: flex;
  align-items: center;
  padding: 0 12px;
  color: #fff;
  font-size: 12px;
  font-weight: 500;
}
.lane--product   .lane__label { color: var(--c-product); }
.lane--marketing .lane__label { color: var(--c-marketing); }
.lane--ops       .lane__label { color: #5d8b2f; }
.lane--product   .lane__bar { background: linear-gradient(90deg, var(--c-product-bg), var(--c-product)); color: var(--c-ink); }
.lane--marketing .lane__bar { background: linear-gradient(90deg, var(--c-marketing-bg), var(--c-marketing)); color: var(--c-ink); }
.lane--ops       .lane__bar { background: linear-gradient(90deg, var(--c-ops-bg), var(--c-ops)); color: var(--c-ink); }

/* =========================================================
   Footer
   ========================================================= */
.site-footer {
  border-top: 1px solid var(--c-line);
  background: var(--c-surface);
  padding: 28px 0 36px;
  margin-top: 64px;
  font-family: var(--f-sans-en);
  font-size: 12.5px;
  color: var(--c-muted);
}
.site-footer__inner {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 0 56px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  align-items: center;
}
.site-footer__inner b { color: var(--c-ink); font-weight: 600; }
.site-footer__inner .dot { color: var(--c-faint); }

/* =========================================================
   TOC drawer (mobile / tablet)
   ========================================================= */
.toc-drawer-scrim {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(20, 30, 45, 0.32);
  z-index: 90;
  opacity: 0;
  transition: opacity .2s ease;
}
.toc-drawer-scrim.is-open { display: block; opacity: 1; }

.toc-drawer {
  display: none;
  position: fixed;
  top: var(--header-h);
  left: 0;
  bottom: 0;
  width: 86%;
  max-width: 340px;
  background: #fff;
  z-index: 100;
  transform: translateX(-100%);
  transition: transform .25s ease;
  overflow-y: auto;
  padding: 24px 20px 64px;
  border-right: 1px solid var(--c-line);
  box-shadow: 6px 0 24px rgba(20, 30, 45, 0.08);
}
.toc-drawer.is-open { transform: translateX(0); }

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width: 1023px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .hamburger { display: inline-flex; }
  .toc-drawer { display: block; }

  .content { padding: 32px 28px 80px; }
  .site-footer__inner { padding: 0 28px; }

  .axis-grid { grid-template-columns: repeat(2, 1fr); }

  .timeline__axis { grid-template-columns: repeat(4, 1fr); padding-top: 64px; }
  .timeline__axis::before { top: 62px; }
  .timeline__tick::after { top: 58px; }
  .timeline__label { bottom: 58px; }

  .goal-hier {
    grid-template-columns: 1fr;
    gap: 18px;
  }
  .retro-loop { flex-direction: row; gap: 14px; padding: 14px; }
  .retro-loop svg { width: 64px; height: 64px; }
}

@media (max-width: 767px) {
  :root { --header-h: 56px; }
  .doc h1 { font-size: 24px; letter-spacing: -0.005em; }

  .site-header { padding: 0 14px; gap: 10px; }
  .site-header__meta { gap: 8px; font-size: 11.5px; }
  .site-header__meta .hide-sm { display: none; }
  .site-header__title-zh { font-size: 13.5px; }

  .content { padding: 24px 18px 64px; }
  .site-footer__inner { padding: 0 18px; font-size: 12px; }

  .doc h1 { font-size: 24px; }
  .doc h2 { font-size: 20px; margin-top: 44px; }
  .doc h3 { font-size: 17px; margin-top: 32px; }

  .axis-grid { grid-template-columns: 1fr; }

  /* Pillars stack vertically — hide arrows on mobile */
  .pillars {
    display: flex;
    flex-direction: column;
    gap: 10px;
  }
  .pillar__arrow { display: none; }

  /* Timeline vertical */
  .timeline { padding: 16px 14px; overflow-x: clip; }
  .timeline__lanes .lane__bar { font-size: 11px; padding: 0 8px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .timeline__tick { padding: 10px 0 10px 44px; min-height: 44px; }
  .timeline__tick::after { left: 22px; top: 22px; width: 12px; height: 12px; }
  .timeline__tick--review::after { width: 14px; height: 14px; left: 22px; top: 21px; }
  .timeline__date { display: inline-block; margin: 0 0 2px; }
  .timeline__label { font-size: 13px; }
  .timeline__axis::before { left: 27px; top: 22px; bottom: 22px; }
  .timeline__axis {
    grid-template-columns: 1fr;
    grid-auto-flow: row;
    padding-top: 0;
    gap: 0;
  }
  .timeline__axis::before {
    left: 18px; right: auto;
    top: 14px; bottom: 14px;
    width: 2px; height: auto;
  }
  .timeline__tick {
    text-align: left;
    padding: 8px 0 8px 36px;
    min-height: 38px;
  }
  .timeline__tick::after {
    left: 18px; top: 18px;
    transform: translate(-50%, 0);
  }
  .timeline__label {
    position: static;
    transform: none;
    display: block;
    margin-top: 2px;
  }

  .pyramid__layer--1, .pyramid__layer--2, .pyramid__layer--3 { width: 100%; }
  .pyramid__layer {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .formula { font-size: 11.5px; padding: 14px; }
}