/* AgentBridge 使用说明书：白纸、单色蓝墨印刷。 */

@font-face {
  font-family: "AB Hei";
  src: url("/assets/fonts/ab-hei-800.woff2") format("woff2");
  font-weight: 800;
  font-display: swap;
}
@font-face {
  font-family: "AB Latin";
  src: url("/assets/fonts/barlow-sc-500.woff2") format("woff2");
  font-weight: 500;
  font-display: swap;
}
@font-face {
  font-family: "AB Latin";
  src: url("/assets/fonts/barlow-sc-700.woff2") format("woff2");
  font-weight: 700;
  font-display: swap;
}

:root {
  --paper: #fcfdff;
  --ink: #0b2552;
  --ink-soft: #3d5580;
  --blue: #0d71fc;          /* 品牌蓝：线条、实底、大号字 */
  --blue-deep: #0a5fd8;     /* 小字与色块：白字对比 ≥ 4.5 */
  --tint: #e8f0ff;          /* 网点浅蓝 */
  --tint-line: #bcd2fb;
  --rule: #c9d7ef;
  --on-blue: #ffffff;
  --on-blue-soft: #e3eeff;
  --display: "AB Latin", "AB Hei", "Microsoft YaHei UI", "PingFang SC", "Noto Sans SC", sans-serif;
  --text: "Microsoft YaHei UI", "Microsoft YaHei", "PingFang SC", "Noto Sans SC", "Segoe UI", system-ui, sans-serif;
  --mono: "Cascadia Mono", Consolas, "SF Mono", ui-monospace, monospace;
  --u: 8px;
  --run-offset: 56px;      /* 正文相对会话线右移的距离 */
  --run-line: 20px;        /* 会话线在页边的位置 */
  --gutter: clamp(16px, 4vw, 56px);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 72px;
  scrollbar-color: var(--tint-line) var(--paper);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--text);
  font-size: 16px;
  line-height: 1.75;
  caret-color: var(--blue);
}

::selection { background: var(--blue-deep); color: var(--on-blue); }

a {
  color: var(--blue-deep);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
}
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--blue); outline-offset: 3px; border-radius: 2px; }

img { max-width: 100%; height: auto; display: block; }
p, li, td, dd { text-wrap: pretty; }

.skip {
  position: absolute; left: 16px; top: -48px; z-index: 50;
  padding: 8px 14px; background: var(--blue-deep); color: var(--on-blue); text-decoration: none;
}
.skip:focus { top: 8px; }

.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap;
}

.num, .code { font-family: var(--display); font-variant-numeric: tabular-nums lining-nums; }
.code { font-weight: 700; letter-spacing: 0.06em; }

/* ---------- 页眉 ---------- */
.runhead {
  position: sticky; top: 0; z-index: 20;
  background: var(--paper);
  border-bottom: 1px solid var(--rule);
}
.runhead-inner {
  display: flex; align-items: center; gap: calc(var(--u) * 3);
  height: 56px; padding: 0 var(--gutter);
}
.runhead-brand {
  display: flex; align-items: center; gap: 10px;
  color: var(--ink); text-decoration: none; font-size: 15px; font-weight: 600;
  white-space: nowrap;
}
.runhead-brand img { border-radius: 6px; }
.runhead-nav { display: flex; gap: calc(var(--u) * 3); margin-left: auto; }
.runhead-nav a {
  color: var(--ink-soft); text-decoration: none; font-size: 14px; white-space: nowrap;
  padding: 4px 0; border-bottom: 2px solid transparent;
}
.runhead-nav a:hover { color: var(--blue-deep); border-bottom-color: var(--blue); }
.runhead-cta {
  padding: 6px 16px; background: var(--blue-deep); color: var(--on-blue);
  text-decoration: none; font-size: 14px; font-weight: 600; white-space: nowrap;
}
.runhead-cta:hover { background: var(--ink); }
@media (max-width: 900px) {
  .runhead-nav { display: none; }
  .runhead-cta { margin-left: auto; }
}

/* ---------- 封面 ---------- */
.cover {
  display: grid;
  grid-template-columns: minmax(380px, 38fr) 62fr;
  grid-template-rows: 1fr auto;
  min-height: clamp(640px, calc(100svh - 56px), 960px);
  border-bottom: 1px solid var(--rule);
}

.cover-panel {
  background: var(--blue-deep);
  color: var(--on-blue);
  padding: calc(var(--u) * 7) var(--gutter) calc(var(--u) * 6);
  display: flex; flex-direction: column;
  grid-column: 1; grid-row: 1;
}

.cover-title { margin: 0; font-family: var(--display); line-height: 1; }
.cover-title-en {
  display: block; font-weight: 700;
  font-size: clamp(48px, 5.4vw, 84px); letter-spacing: -0.01em;
}
.cover-title-zh {
  display: block; margin-top: calc(var(--u) * 1.5);
  font-weight: 800; font-size: clamp(28px, 2.6vw, 40px); letter-spacing: 0.3em;
}

.cover-claim {
  margin: calc(var(--u) * 5) 0 0;
  padding-top: calc(var(--u) * 2.5);
  border-top: 2px solid var(--on-blue);
  font-family: var(--display); font-weight: 800;
  font-size: clamp(22px, 1.9vw, 28px); line-height: 1.4;
}
.cover-lead { margin: calc(var(--u) * 1.5) 0 0; color: var(--on-blue-soft); font-size: 16px; max-width: 30em; }

.cover-actions { display: flex; flex-wrap: wrap; gap: calc(var(--u) * 1.5); margin-top: calc(var(--u) * 4); }
.cover-meta { margin: calc(var(--u) * 1.5) 0 0; color: var(--on-blue-soft); font-size: 14px; }
.cover-meta .code { color: var(--on-blue); font-size: 16px; }
.cover-meta span { display: block; }

/* 按钮：印刷色块，直角 */
.btn {
  display: inline-flex; align-items: baseline; gap: 10px;
  min-height: 48px; padding: 12px 22px;
  font-size: 16px; font-weight: 700; text-decoration: none;
  border: 2px solid transparent;
  transition: background-color .2s var(--ease-out), color .2s var(--ease-out), border-color .2s var(--ease-out);
}
.btn-note { font-size: 13px; font-weight: 500; }
.btn-paper { background: var(--on-blue); color: var(--blue-deep); }
.btn-paper:hover { background: var(--ink); color: var(--on-blue); }
.btn-line { color: var(--on-blue); border-color: var(--on-blue-soft); }
.btn-line:hover { background: var(--on-blue); color: var(--blue-deep); }
.cover .btn:focus-visible, .get .btn:focus-visible { outline-color: var(--on-blue); }

/* 目录 */
.toc {
  grid-column: 1; grid-row: 2;
  background: var(--blue-deep); color: var(--on-blue);
  padding: 0 var(--gutter) calc(var(--u) * 6);
}
.toc-title {
  margin: 0 0 var(--u); font-size: 13px; letter-spacing: 0.4em; color: var(--on-blue-soft);
}
.toc ol { list-style: none; margin: 0; padding: 0; border-top: 1px solid rgba(255, 255, 255, .45); }
.toc a {
  display: flex; align-items: baseline; gap: 14px;
  padding: 9px 0; color: var(--on-blue); text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, .45);
}
.toc-no { font-family: var(--display); font-weight: 700; font-size: 18px; width: 1.2em; }
.toc-name { font-family: var(--display); font-weight: 800; font-size: 16px; }
.toc-dots { flex: 1; border-bottom: 2px dotted rgba(255, 255, 255, .5); transform: translateY(-4px); }
.toc-hint { font-size: 13px; color: var(--on-blue-soft); }
.toc a:hover .toc-name { text-decoration: underline; text-underline-offset: .25em; }

/* ---------- 图 1 ---------- */
.fig1 {
  margin: 0;
  grid-column: 2; grid-row: 1 / span 2;
  padding: calc(var(--u) * 6) var(--gutter) calc(var(--u) * 4);
  display: flex; flex-direction: column; justify-content: center;
  background-color: var(--paper);
  background-image: radial-gradient(circle, rgba(13, 113, 252, .16) 1px, transparent 1.4px);
  background-size: 8px 8px;
}

.fig1-board {
  position: relative;
  aspect-ratio: 720 / 540;
  container-type: inline-size;
  width: 100%; max-width: 900px; margin: 0 auto;
}

.fig-label {
  margin: 0; font-size: max(12px, 1.75cqw); font-weight: 600; letter-spacing: .04em;
  color: var(--blue-deep); background: var(--paper); padding: 0 6px; width: max-content;
}

.fig1-helper { position: absolute; left: 0; top: 0; width: 51.7%; }
.fig1-helper .fig-label { margin-bottom: 1.6cqw; }

.chat {
  position: relative;
  min-height: 27.8cqw;
  display: flex; flex-direction: column; justify-content: center; gap: 1.6cqw;
  padding: 2.6cqw 3cqw;
  background: var(--paper);
  border: 1.5px solid var(--blue);
  box-shadow: 0 1.2cqw 3cqw rgba(11, 37, 82, .10);
}
.chat-tag {
  position: absolute; top: -1px; right: -1px; margin: 0;
  padding: .3cqw 1.2cqw; background: var(--blue-deep); color: var(--on-blue);
  font-size: max(11px, 1.45cqw); letter-spacing: .1em;
}
.chat-line { display: flex; gap: 1.6cqw; margin: 0; font-size: max(13px, 1.95cqw); line-height: 1.55; }
.chat-who {
  flex: none; width: 5.6cqw; font-family: var(--display); font-weight: 700;
  color: var(--blue-deep); font-size: max(12px, 1.8cqw); padding-top: .15em;
}
.chat-agent { color: var(--ink); }
.chat-done {
  display: flex; align-items: center; gap: 1cqw; margin: 0;
  padding-top: 1.4cqw; border-top: 1px dashed var(--tint-line);
  font-size: max(12px, 1.8cqw); font-weight: 600; color: var(--blue-deep);
}
.chat-done svg { width: max(14px, 2.2cqw); fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.fig1-recipient { position: absolute; left: 44.4%; top: 44%; width: 50%; }
.fig1-recipient .fig-label { margin-bottom: 1.6cqw; }
.shot { position: relative; }
.shot img {
  width: 100%;
  border: 1.5px solid var(--blue);
  box-shadow: 0 1.2cqw 3cqw rgba(11, 37, 82, .12);
}

/* 会话线：从协助者的对话接到受助者的电脑 */
.session-h, .session-v { position: absolute; pointer-events: none; }
.session-h { left: 51.7%; top: 25.9%; width: 32.3%; border-top: 3px solid var(--blue); }
.session-v { left: 84%; top: calc(25.9% - 1.5px); height: 22.6%; border-left: 3px solid var(--blue); }
.session-v::after {
  content: ""; position: absolute; left: -7.5px; bottom: -2px;
  border: 6px solid transparent; border-top: 9px solid var(--blue);
}

.lock {
  position: absolute; left: 67.8%; top: 25.9%; transform: translate(-50%, -50%);
  display: flex; align-items: center; gap: .8cqw;
  padding: .5cqw 1.2cqw; background: var(--paper); border: 1px solid var(--blue);
  font-size: max(12px, 1.6cqw); font-weight: 600; color: var(--blue-deep); white-space: nowrap;
}
.lock svg { width: max(13px, 1.9cqw); fill: none; stroke: currentColor; stroke-width: 1.6; }

/* 部件编号与引线 */
.callout {
  position: absolute; z-index: 2;
  display: grid; place-items: center;
  width: max(22px, 3.6cqw); height: max(22px, 3.6cqw); border-radius: 50%;
  background: var(--paper); border: 2px solid var(--blue); color: var(--blue-deep);
  font-family: var(--display); font-weight: 700; font-size: max(13px, 2.1cqw); line-height: 1;
  transition: background-color .25s var(--ease-out), color .25s var(--ease-out), transform .25s var(--ease-out);
}
.callout::before { content: ""; position: absolute; top: 50%; height: 0; border-top: 1.5px solid var(--blue); }
.callout-1 { left: calc(100% + 4.5cqw); top: 2.6cqw; }
.callout-1::before { right: 100%; width: 4.5cqw; }
.callout-3 { left: calc(84% - 7.6cqw); top: 35%; }
.callout-3::before { left: 100%; width: 3.6cqw; }
.callout-2 { left: 46%; top: 89%; transform: translateY(-50%); }
.callout-2::before { right: 100%; width: 4cqw; }
.callout-4 { left: 70%; top: 58.4%; transform: translateY(-50%); }
.callout-4::before { left: 100%; width: 6.8cqw; }

.parts {
  list-style: none; margin: calc(var(--u) * 4) auto 0; padding: 0;
  width: 100%; max-width: 900px;
  display: grid; grid-template-columns: 1fr 1fr; column-gap: calc(var(--u) * 4);
  border-top: 1px solid var(--rule);
}
.part {
  display: flex; gap: 12px; padding: 12px 0; border-bottom: 1px solid var(--rule);
  font-size: 14px; color: var(--ink-soft); line-height: 1.6; cursor: default;
}
.part b { display: block; color: var(--ink); font-size: 15px; }
.part-no {
  flex: none; display: grid; place-items: center; width: 24px; height: 24px; border-radius: 50%;
  border: 2px solid var(--blue); color: var(--blue-deep);
  font-family: var(--display); font-weight: 700; font-size: 14px; line-height: 1;
  transition: background-color .25s var(--ease-out), color .25s var(--ease-out);
}
.part:hover .part-no, .part:focus-visible .part-no { background: var(--blue-deep); color: var(--on-blue); }

.fig1:has(.part-1:is(:hover, :focus-visible)) .callout-1,
.fig1:has(.part-2:is(:hover, :focus-visible)) .callout-2,
.fig1:has(.part-3:is(:hover, :focus-visible)) .callout-3,
.fig1:has(.part-4:is(:hover, :focus-visible)) .callout-4 {
  background: var(--blue-deep); color: var(--on-blue); border-color: var(--blue-deep);
}
.fig1:has(.part-1:is(:hover, :focus-visible)) .callout-1::before,
.fig1:has(.part-2:is(:hover, :focus-visible)) .callout-2::before,
.fig1:has(.part-3:is(:hover, :focus-visible)) .callout-3::before,
.fig1:has(.part-4:is(:hover, :focus-visible)) .callout-4::before {
  border-top: 3px solid var(--blue-deep); margin-top: -0.75px;
}
.fig1:has(.part-1:is(:hover, :focus-visible)) .chat,
.fig1:has(.part-3:is(:hover, :focus-visible)) .lock { outline: 3px solid var(--tint-line); outline-offset: 3px; }
.ring {
  position: absolute; pointer-events: none; opacity: 0;
  border: 2px solid var(--blue-deep); border-radius: 4px; box-shadow: 0 0 0 4px rgba(13, 113, 252, .18);
  transition: opacity .25s var(--ease-out);
}
.ring-2 { left: 3%; top: 82%; width: 35%; height: 14%; }
.ring-4 { left: 84.5%; top: 52.5%; width: 10.5%; height: 12%; }
.fig1:has(.part-2:is(:hover, :focus-visible)) .ring-2,
.fig1:has(.part-4:is(:hover, :focus-visible)) .ring-4 { opacity: 1; }

.fig1 figcaption, .fig3 figcaption {
  margin: calc(var(--u) * 2) auto 0; width: 100%; max-width: 900px;
  font-size: 13px; color: var(--ink-soft);
}
.fig1 figcaption b, .fig3 figcaption b { font-family: var(--display); color: var(--blue-deep); }

/* 加载时会话线画一次 */
@media (prefers-reduced-motion: no-preference) {
  .session-h { animation: draw-h .7s var(--ease-out) .35s backwards; }
  .session-v { animation: draw-v .55s var(--ease-out) 1s backwards; }
  .lock { animation: settle .5s var(--ease-out) 1.45s backwards; }
}
@keyframes draw-h { from { clip-path: inset(0 100% 0 0); } to { clip-path: inset(0 0 0 0); } }
@keyframes draw-v { from { clip-path: inset(0 0 100% 0); } to { clip-path: inset(0 0 -12px 0); } }
@keyframes settle { from { opacity: 0; filter: blur(4px); } to { opacity: 1; filter: blur(0); } }
.session-v { clip-path: inset(0 0 -12px 0); }

/* ---------- 章节 ---------- */
.chapter {
  position: relative;
  padding: calc(var(--u) * 12) var(--gutter) calc(var(--u) * 8) calc(var(--gutter) + var(--run-offset));
  max-width: 1200px; margin: 0 auto;
}
/* 会话线：从图 1 下方沿页边贯穿第 1–4 章，接进授权状态表，在“已结束”处截断 */
/* top: -1px 盖住章节之间的分隔线，线不断开 */
.chapter.run::before, .run-seg::before {
  content: ""; position: absolute; top: -1px; bottom: 0; z-index: 1;
  left: calc(var(--gutter) + var(--run-line)); border-left: 3px solid var(--blue);
}
.chapter.chapter-end { padding-top: 0; }
.run-seg { position: relative; display: flow-root; padding-top: calc(var(--u) * 12); }
.run-seg::before { left: calc(var(--run-line) - var(--run-offset)); }
.chapter + .chapter { border-top: 1px solid var(--rule); }
.chapter-head {
  display: flex; align-items: flex-end; gap: calc(var(--u) * 3);
  padding-bottom: calc(var(--u) * 2); margin-bottom: calc(var(--u) * 4);
  border-bottom: 3px solid var(--blue);
}
.chapter-no {
  font-family: var(--display); font-weight: 700; color: var(--blue);
  font-size: clamp(64px, 7vw, 104px); line-height: .78;
}
.chapter h2 {
  margin: 0; font-family: var(--display); font-weight: 800;
  font-size: clamp(28px, 3vw, 40px); line-height: 1.2; letter-spacing: .04em;
}
.chapter-lead { margin: 0 0 calc(var(--u) * 4); color: var(--ink-soft); max-width: 40em; }

/* 1 先看你是谁 */
.roles { display: grid; grid-template-columns: 1fr 1fr; }
.role { padding: 0 calc(var(--u) * 5) 0 0; }
.role + .role { padding: 0 0 0 calc(var(--u) * 5); border-left: 1px solid var(--rule); }
.role h3 { margin: 0; font-family: var(--display); font-weight: 800; font-size: 24px; }
.role-who { margin: 4px 0 calc(var(--u) * 2); color: var(--blue-deep); font-weight: 600; }
.role p { max-width: 34em; }
.role-link { display: inline-block; margin-top: var(--u); font-weight: 600; }

/* 2 操作步骤 */
.steps {
  display: grid;
  grid-template-columns: 1fr minmax(120px, 160px) 1fr;
  grid-template-rows: auto repeat(3, auto);
}
.steps-col { display: grid; grid-template-rows: subgrid; grid-row: 1 / span 4; }
#steps-recipient { grid-column: 1; }
#steps-helper { grid-column: 3; }
.steps-who {
  margin: 0 0 var(--u); font-family: var(--display); font-weight: 800; font-size: 20px;
  color: var(--blue-deep); letter-spacing: .12em;
}
.steps-col ol { list-style: none; margin: 0; padding: 0; display: grid; grid-template-rows: subgrid; grid-row: 2 / span 3; }
.steps-col li { display: flex; gap: calc(var(--u) * 2); padding: calc(var(--u) * 2.5) 0; border-top: 1px solid var(--rule); }
.steps-col li:last-child { border-bottom: 1px solid var(--rule); }
.steps-col li b { font-size: 18px; }
.steps-col li p { margin: 2px 0 0; color: var(--ink-soft); }
.step-no {
  flex: none; display: grid; place-items: center; width: 36px; height: 36px; border-radius: 50%;
  border: 2px solid var(--blue); color: var(--blue-deep);
  font-family: var(--display); font-weight: 700; font-size: 20px; line-height: 1;
}
.steps-col li:last-child .step-no { background: var(--blue-deep); border-color: var(--blue-deep); color: var(--on-blue); }
.steps-join { grid-column: 2; grid-row: 4; position: relative; }
.steps-join::before {
  content: ""; position: absolute; left: 0; right: 0; top: calc(var(--u) * 2.5 + 18px);
  border-top: 3px solid var(--blue);
}
.steps-join::after {
  content: "会话接通"; position: absolute; left: 50%; top: calc(var(--u) * 2.5 + 18px);
  transform: translate(-50%, -50%);
  padding: 2px 10px; background: var(--paper); border: 1px solid var(--blue);
  font-size: 13px; font-weight: 600; color: var(--blue-deep); white-space: nowrap;
}

/* 表格（功能说明、状态表、规格） */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
th, td { text-align: left; vertical-align: top; padding: 14px 16px 14px 0; border-bottom: 1px solid var(--rule); }
thead th {
  padding-top: 0; font-size: 13px; letter-spacing: .12em; color: var(--blue-deep);
  border-bottom: 2px solid var(--blue);
}
tbody th { font-weight: 700; white-space: nowrap; }
.ftable td:last-child { color: var(--ink-soft); }
.ftable th[scope="row"] { width: 9em; }
.ftable td:nth-child(2) { width: 46%; }

/* 4 注意事项 */
.caution {
  border: 1.5px solid var(--blue);
  padding: calc(var(--u) * 3) calc(var(--u) * 4);
  margin-bottom: calc(var(--u) * 7);
  background: var(--tint);
}
.caution-title {
  display: flex; align-items: center; gap: 10px; margin: 0 0 var(--u);
  font-family: var(--display); font-weight: 800; font-size: 22px; color: var(--blue-deep); letter-spacing: .2em;
}
.caution-title svg { width: 26px; fill: none; stroke: var(--blue-deep); stroke-width: 1.8; stroke-linejoin: round; stroke-linecap: round; }
.caution ul { margin: 0; padding-left: 1.2em; }
.caution li { padding: 4px 0; }
.caution li::marker { color: var(--blue); }

.sub-title { margin: 0 0 var(--u); font-family: var(--display); font-weight: 800; font-size: 22px; }

.stable-wrap { margin-left: calc(-1 * var(--run-offset)); }
.stable td.st-line, .stable thead th:first-child { width: var(--run-offset); padding: 0; position: relative; border-bottom-color: transparent; }
.stable tbody th { color: var(--blue-deep); }
.st-line::before, .stable thead th:first-child::before {
  content: ""; position: absolute; left: var(--run-line); top: 0; bottom: -2px;
  border-left: 3px solid var(--blue);
}
.st-pause .st-line::before, .st-off .st-line::before { border-left-style: dashed; }
/* 截断位置对齐该行第一行文字 */
.st-end .st-line::before { bottom: auto; height: calc(14px + 0.875em); }
.st-end .st-line::after {
  content: ""; position: absolute; left: calc(var(--run-line) - 8px); top: calc(14px + 0.875em);
  width: 19px; border-top: 3px solid var(--blue);
}
.st-end th, .st-end td { color: var(--ink-soft); }
.table-note { margin: calc(var(--u) * 2) 0 0; font-size: 14px; color: var(--ink-soft); max-width: 48em; }

.fig3 { margin: calc(var(--u) * 6) 0 0; max-width: 760px; }
.fig3 img { border: 1px solid var(--rule); }
.fig3 figcaption { max-width: none; }

/* 5 规格与下载 */
.specs { display: grid; grid-template-columns: 1fr minmax(320px, 420px); gap: calc(var(--u) * 6); align-items: start; }
.spec-list { margin: 0; border-top: 2px solid var(--blue); }
.spec-list div { display: grid; grid-template-columns: 9em 1fr; gap: 16px; padding: 12px 0; border-bottom: 1px solid var(--rule); }
.spec-list dt { color: var(--blue-deep); font-weight: 600; }
.spec-list dd { margin: 0; }
.spec-list .num { font-weight: 700; font-size: 17px; }

.get {
  background: var(--blue-deep); color: var(--on-blue);
  padding: calc(var(--u) * 4);
  display: flex; flex-direction: column; align-items: flex-start; gap: calc(var(--u) * 1.5);
}
.get-title { margin: 0 0 var(--u); font-family: var(--display); font-weight: 800; font-size: 24px; }
.get .btn { width: 100%; justify-content: center; }
.btn-ink { background: var(--on-blue); color: var(--blue-deep); }
.btn-ink:hover { background: var(--ink); color: var(--on-blue); }
.btn-outline { color: var(--on-blue); border-color: var(--on-blue-soft); }
.btn-outline:hover { background: var(--on-blue); color: var(--blue-deep); }
.get-code { margin: 0 0 var(--u); color: var(--on-blue-soft); font-size: 14px; }
.get-code .code { color: var(--on-blue); font-size: 18px; }
.get a:not(.btn) { color: var(--on-blue); }
.get ::selection { background: var(--on-blue); color: var(--blue-deep); }

.hash { width: 100%; margin-top: var(--u); padding-top: calc(var(--u) * 1.5); border-top: 1px solid rgba(255, 255, 255, .4); }
.hash summary { cursor: pointer; font-size: 14px; color: var(--on-blue-soft); }
.hash summary:hover { color: var(--on-blue); }
.hash p { margin: var(--u) 0 4px; font-size: 13px; color: var(--on-blue-soft); }
.hash-value, .hash-cmd {
  display: block; margin-top: var(--u); padding: 8px 10px;
  background: rgba(255, 255, 255, .12); color: var(--on-blue);
  font-family: var(--mono); font-size: 12.5px; line-height: 1.6; overflow-wrap: anywhere;
}
.get-more { margin: 0; font-size: 14px; color: var(--on-blue-soft); }

/* 版权页 */
.colophon { border-top: 3px solid var(--blue); }
.colophon-inner {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px;
  padding: calc(var(--u) * 3) var(--gutter) calc(var(--u) * 4);
  font-size: 13px; color: var(--ink-soft);
}
.colophon p { margin: 0; }

/* ---------- 窄屏 ---------- */
@media (max-width: 1100px) {
  .cover { grid-template-columns: 1fr; grid-template-rows: none; min-height: 0; }
  .cover-panel, .fig1, .toc { grid-column: auto; grid-row: auto; }
  .cover-panel { padding-top: calc(var(--u) * 6); }
  .toc { padding-top: calc(var(--u) * 5); }
}

@media (max-width: 720px) {
  .fig1 { padding-top: calc(var(--u) * 4); }
  .fig1-board { aspect-ratio: auto; container-type: normal; display: flex; flex-direction: column; }
  .fig1-helper, .fig1-recipient { position: relative; left: auto; top: auto; width: auto; }
  .fig-label { font-size: 12px; }
  .fig1-helper .fig-label, .fig1-recipient .fig-label { margin-bottom: 8px; }
  .chat { min-height: 0; gap: 10px; padding: 18px 16px 14px; }
  .chat-tag { font-size: 11px; padding: 2px 8px; }
  .chat-line { font-size: 14px; gap: 10px; }
  .chat-who { width: 3.2em; font-size: 13px; }
  .chat-done { font-size: 13px; gap: 6px; padding-top: 10px; }
  .chat-done svg { width: 14px; }
  .board-mid { position: relative; height: 88px; margin: 6px 0 10px; }
  .session-h { display: none; }
  .session-v { left: 22px; top: 0; height: calc(100% - 10px); }
  .callout { width: 24px; height: 24px; font-size: 13px; }
  .callout-3 { left: 44px; top: 50%; transform: translateY(-50%); }
  .callout-3::before { left: auto; right: 100%; width: 19px; }
  .lock { position: absolute; left: 80px; top: 50%; transform: translateY(-50%); font-size: 12px; padding: 3px 8px; gap: 6px; }
  .lock svg { width: 13px; }
  .callout-1 { left: auto; right: 0; top: -3px; }
  .callout-1::before { display: none; }
  .callout-2::before { width: 32px; }
  .callout-4::before { width: 34px; }
  .parts { grid-template-columns: 1fr; }

  :root { --run-offset: 26px; --run-line: 4px; }
  .chapter { padding-top: calc(var(--u) * 8); padding-bottom: calc(var(--u) * 6); }
  .run-seg { padding-top: calc(var(--u) * 8); }
  .chapter-head { gap: calc(var(--u) * 2); }
  .roles { grid-template-columns: 1fr; }
  .role, .role + .role { padding: 0; border-left: 0; }
  .role + .role { margin-top: calc(var(--u) * 4); padding-top: calc(var(--u) * 4); border-top: 1px solid var(--rule); }

  .steps { display: block; }
  .steps-col { display: block; }
  .steps-col ol { display: block; }
  #steps-helper { margin-top: calc(var(--u) * 5); }
  .steps-join { display: none; }

  .ftable thead { display: none; }
  .ftable, .ftable tbody, .ftable tr, .ftable th, .ftable td { display: block; width: auto !important; }
  .ftable tr { padding: 14px 0; border-bottom: 1px solid var(--rule); }
  .ftable th, .ftable td { border: 0; padding: 2px 0; }
  .ftable td:last-child { font-size: 14px; }
  .ftable tbody th { white-space: normal; font-size: 17px; color: var(--blue-deep); }

  .caution { padding: calc(var(--u) * 2.5); }
  .stable th, .stable td { padding-right: 10px; font-size: 14px; }

  .specs { grid-template-columns: 1fr; }
  .spec-list div { grid-template-columns: 7em 1fr; }
}