:root {
  --navy: #153642;
  --navy-deep: #0e2a35;
  --navy-soft: #224a54;
  --sea: #397d83;
  --sea-light: #c5e5dc;
  --coral: #d98560;
  --paper: #f3f6f3;
  --white: #fff;
  --ink: #263b42;
  --muted: #576e73;
  --line: #d9e2de;
  --focus: #a34a25;
  --sans: "Avenir Next", Avenir, "Segoe UI", sans-serif;
  --serif: "Iowan Old Style", "Baskerville", Georgia, serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.64 var(--sans); }
button, input { font: inherit; }
a { color: var(--sea); text-underline-offset: 3px; }
button { cursor: pointer; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
::selection { background: var(--sea-light); color: var(--navy-deep); }

.skip-link { position: fixed; z-index: 50; top: -80px; left: 16px; background: var(--white); color: var(--navy); padding: 8px 16px; }
.skip-link:focus { top: 16px; }
.shell { display: grid; grid-template-columns: 266px minmax(0, 1fr); min-height: 100vh; }
.rail { position: sticky; top: 0; display: flex; flex-direction: column; height: 100vh; padding: 34px 22px 24px; background: var(--navy-deep); color: #e6f1eb; }
.brand { display: flex; align-items: center; gap: 13px; width: fit-content; color: inherit; text-decoration: none; }
.brand strong, .brand small { display: block; }
.brand strong { font: 600 25px/1 var(--serif); letter-spacing: -.03em; }
.brand small { margin-top: 4px; color: #9bc4c4; font-size: 12px; letter-spacing: .04em; }
.brand-mark { position: relative; width: 34px; height: 34px; display: block; border: 1px solid #9bc4c4; border-radius: 50%; overflow: hidden; }
.brand-mark span { position: absolute; width: 23px; height: 10px; border-top: 2px solid var(--sea-light); border-radius: 50%; transform: rotate(-25deg); }
.brand-mark span:nth-child(1) { top: 8px; left: 1px; }
.brand-mark span:nth-child(2) { top: 15px; left: 11px; }
.brand-mark span:nth-child(3) { top: 22px; left: -7px; }
.rail-tools { margin-top: 48px; }
.rail-tools label { display: block; color: #bfd5d1; font-size: 13px; margin-bottom: 8px; }
.search-wrap { position: relative; }
.search-wrap svg { position: absolute; width: 16px; height: 16px; top: 11px; left: 12px; fill: none; stroke: #9fc4c4; stroke-width: 1.8; }
.search-wrap input { width: 100%; height: 40px; border: 1px solid #466873; border-radius: 5px; padding: 8px 12px 8px 36px; background: #1b404d; color: var(--white); font-size: 13px; }
.search-wrap input::placeholder { color: #a7c3c2; }
.search-wrap input:focus { border-color: var(--sea-light); }
.search-status { min-height: 24px; margin: 6px 0 0; color: #aac8c7; font-size: 12px; }
.rail nav { margin-top: 23px; overflow-y: auto; scrollbar-width: none; }
.rail nav::-webkit-scrollbar { display: none; }
.rail nav a { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 10px 10px; border-left: 2px solid transparent; color: #bed2d0; text-decoration: none; font-size: 14px; line-height: 1.3; }
.rail nav a:hover, .rail nav a.active { color: var(--white); background: #1a424d; border-left-color: var(--coral); }
.rail nav a[hidden] { display: none; }
.rail nav em { color: #85aaa9; font: normal 11px var(--mono); }
.rail-foot { margin-top: auto; padding: 17px 9px 0; display: flex; gap: 10px; border-top: 1px solid #315561; color: #a7c4c2; font-size: 11px; line-height: 1.5; }
.signal-dot { flex: none; width: 7px; height: 7px; margin-top: 5px; border-radius: 50%; background: var(--sea-light); box-shadow: 0 0 0 4px #315a60; }

main { min-width: 0; }
.chapter { width: min(100%, 1030px); padding: 78px clamp(28px, 7vw, 110px) 84px; border-bottom: 1px solid var(--line); scroll-margin-top: 12px; }
.chapter-start { width: 100%; max-width: none; padding: 0; }
.hero { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(275px, .75fr); min-height: 450px; color: var(--white); background: var(--navy); }
.hero-copy { padding: 76px clamp(28px, 7vw, 110px) 70px; }
.chapter-kicker { margin: 0 0 14px; color: var(--sea); font-size: 13px; font-weight: 700; letter-spacing: .045em; }
.hero .chapter-kicker { color: #b6d8d0; }
h1, h2, h3, p { margin-top: 0; }
h1, h2 { font-family: var(--serif); letter-spacing: -.035em; }
h1 { max-width: 660px; margin-bottom: 22px; font-size: clamp(42px, 5vw, 70px); line-height: 1.04; font-weight: 500; }
.hero-lead { max-width: 640px; color: #d7e9e5; font-size: 18px; line-height: 1.55; }
.hero-link { display: inline-flex; align-items: center; gap: 30px; margin-top: 20px; padding: 12px 0; border-bottom: 1px solid var(--sea-light); color: var(--white); text-decoration: none; font-weight: 600; }
.hero-link span { font-size: 22px; line-height: 1; }
.signal-graphic { position: relative; display: flex; flex-direction: column; justify-content: center; min-height: 320px; padding: 60px 44px; overflow: hidden; background: #1b4651; }
.signal-graphic::before, .signal-graphic::after { content: ""; position: absolute; width: 420px; height: 420px; border: 1px solid #38646a; border-radius: 50%; left: 45%; top: -155px; }
.signal-graphic::after { width: 280px; height: 280px; left: 68%; top: -87px; }
.signal-line { position: relative; z-index: 1; display: flex; justify-content: space-between; width: 94%; height: 2px; margin: 0 0 26px 10px; background: #89bbb4; transform: rotate(-7deg); }
.signal-line i { display: block; width: 11px; height: 11px; margin-top: -5px; border: 2px solid #c4e3da; border-radius: 50%; background: #1b4651; }
.signal-line i:last-child { background: var(--coral); border-color: var(--coral); }
.signal-graphic ol { position: relative; z-index: 1; display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 0; padding: 0; list-style: none; }
.signal-graphic li { min-width: 0; }
.signal-graphic b, .signal-graphic span { display: block; }
.signal-graphic b { font-family: var(--serif); font-size: 18px; font-weight: 500; }
.signal-graphic span { color: #bddbd5; font-size: 12px; }
.intro-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 55px; max-width: 1120px; padding: 54px clamp(28px, 7vw, 110px) 65px; }
.intro-grid h2 { font-size: 28px; font-weight: 500; }
.intro-grid p { margin-bottom: 0; }

.chapter-heading { display: grid; grid-template-columns: 46px minmax(0, 1fr); gap: 24px; margin-bottom: 45px; }
.chapter-number { display: grid; place-items: center; width: 38px; height: 38px; border: 1px solid #a8c5c1; border-radius: 50%; color: var(--sea); font: 12px var(--mono); }
.chapter-heading h2 { margin: 0 0 10px; color: var(--navy); font-size: clamp(35px, 3.5vw, 49px); line-height: 1.1; font-weight: 500; }
.chapter-heading p:last-child { max-width: 650px; margin-bottom: 0; color: var(--muted); font-size: 17px; }
h3 { margin-bottom: 8px; color: var(--navy); font-size: 19px; line-height: 1.35; font-weight: 650; }
p { max-width: 72ch; }
code { font: .9em/1.4 var(--mono); }
p code { padding: 2px 4px; border-radius: 3px; background: #e3ebe7; color: #254c52; }
.micro { color: var(--muted); font-size: 13px; }
.step-list { border-top: 1px solid var(--line); }
.step { display: grid; grid-template-columns: 42px minmax(0, 1fr); gap: 24px; padding: 26px 0 28px; border-bottom: 1px solid var(--line); }
.step-index { display: grid; place-items: center; width: 31px; height: 31px; border-radius: 3px; background: var(--sea-light); color: var(--navy); font: 600 13px var(--mono); }
.step p:last-child { margin-bottom: 0; }
.command { overflow: hidden; max-width: 100%; margin: 18px 0 12px; border-radius: 5px; background: var(--navy-deep); color: #eaf4ee; }
.command-top { display: flex; align-items: center; justify-content: space-between; min-height: 36px; padding: 5px 10px 5px 18px; border-bottom: 1px solid #34535e; color: #a7c7c5; font-size: 12px; }
.command button { padding: 5px 10px; border: 1px solid #57747b; border-radius: 3px; background: transparent; color: var(--white); font-size: 12px; }
.command button:hover { background: #2b535e; }
.command > code { display: block; overflow-x: auto; padding: 17px 18px 20px; white-space: pre; font-size: 12px; line-height: 1.5; }
.setup-check { display: grid; grid-template-columns: .9fr 1.1fr; gap: 10px 30px; margin: 38px 0 52px; padding: 29px; border: 1px solid #b5d0c9; border-radius: 5px; background: #e8f0eb; }
.setup-check h3 { margin-bottom: 4px; }
.setup-check p { margin-bottom: 0; color: var(--muted); font-size: 13px; }
.check-items { display: grid; gap: 7px; }
.check-items label { display: flex; align-items: start; gap: 10px; cursor: pointer; font-size: 14px; }
.check-items input { width: 16px; height: 16px; margin-top: 4px; accent-color: var(--sea); }
.setup-check .check-status { grid-column: 2; margin-top: 5px; color: var(--sea); font-weight: 700; }
.subsection { margin-top: 20px; }
.subsection > h3 { font-family: var(--serif); font-size: 27px; font-weight: 500; }
.segmented { display: inline-flex; flex-wrap: wrap; margin: 8px 0 4px; padding: 3px; border: 1px solid var(--line); border-radius: 5px; background: #e8efea; }
.segmented button { min-height: 36px; padding: 6px 15px; border: 0; border-radius: 3px; background: transparent; color: var(--muted); font-size: 13px; }
.segmented button[aria-pressed="true"] { background: var(--white); color: var(--navy); font-weight: 700; box-shadow: 0 1px 4px #a8bcb544; }
.report-rows { border-top: 1px solid var(--line); }
.report-rows > div { display: grid; grid-template-columns: 160px minmax(0, 1fr); gap: 22px; padding: 24px 0; border-bottom: 1px solid var(--line); }
.report-rows p { margin-bottom: 0; }
.report-time { padding-top: 3px; color: var(--sea); font-size: 13px; font-weight: 700; }
.note { margin-top: 34px; padding: 25px 27px; border-left: 3px solid var(--coral); background: #e6ede8; }
.note strong { display: block; margin-bottom: 8px; color: var(--navy); }
.note p:last-child { margin-bottom: 0; }
.note-plain { margin-top: 0; border-left-color: var(--sea); }
.note .command { margin-bottom: 0; }
.alarm-example { overflow: hidden; margin-bottom: 30px; border: 1px solid #c6d7d2; border-radius: 5px; background: var(--white); box-shadow: 0 14px 30px #2347520b; }
.mail-top { display: flex; gap: 10px; align-items: center; padding: 12px 19px; border-bottom: 1px solid var(--line); color: var(--muted); font-size: 12px; }
.mail-icon { display: grid; place-items: center; width: 25px; height: 25px; border-radius: 50%; background: var(--sea-light); color: var(--navy); font-size: 14px; }
.mail-subject { margin: 0; padding: 19px 22px 8px; color: var(--navy); font-weight: 700; }
.mail-body { padding: 0 22px 23px; font-size: 14px; }
.mail-body span { color: var(--muted); font-family: var(--mono); font-size: 12px; }
.mail-body p { margin: 12px 0 0; }
.mail-table-wrap { overflow-x: auto; margin-top: 14px; }
.mail-table { width: 100%; border-collapse: collapse; min-width: 480px; font-size: 12px; text-align: left; }
.mail-table th, .mail-table td { padding: 9px 8px; border-bottom: 1px solid var(--line); vertical-align: top; }
.mail-table th { color: var(--navy); background: #e9f1ed; }
.mail-table td:last-child { color: var(--sea); font-weight: 700; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; margin: 28px 0 36px; }
.two-col > div { padding-top: 17px; border-top: 2px solid #b8d1c9; }
.two-col p { margin-bottom: 0; }
.ops-list > div { margin-bottom: 38px; padding-bottom: 20px; border-bottom: 1px solid var(--line); }
.ops-list > div:last-child { border-bottom: 0; }
.ops-list p { margin-bottom: 0; }
.troubleshooting { border-top: 1px solid var(--line); }
.troubleshooting details { border-bottom: 1px solid var(--line); }
.troubleshooting summary { position: relative; padding: 20px 37px 20px 0; color: var(--navy); font-weight: 650; cursor: pointer; list-style: none; }
.troubleshooting summary::-webkit-details-marker { display: none; }
.troubleshooting summary::after { content: "+"; position: absolute; right: 10px; top: 16px; font: 26px/1 var(--serif); color: var(--sea); }
.troubleshooting details[open] summary::after { content: "−"; }
.troubleshooting details > div { padding: 0 30px 22px 0; }
.troubleshooting details p:last-child { margin-bottom: 0; }
.boundaries > div:last-child { border-top-color: var(--coral); }
.admin-step { padding: 30px 0 32px; border-bottom: 1px solid var(--line); }
.admin-step:last-of-type { border-bottom: 0; }
.admin-step-label { margin-bottom: 11px; color: var(--sea); font-size: 13px; font-weight: 700; }
.admin-step h3 { font: 500 27px/1.25 var(--serif); }
.admin-code { overflow: hidden; margin: 18px 0 22px; border-radius: 5px; background: var(--navy-deep); color: #eaf4ee; }
.admin-code .command-top { padding-left: 18px; }
.admin-code button { padding: 5px 10px; border: 1px solid #57747b; border-radius: 3px; background: transparent; color: var(--white); font-size: 12px; }
.admin-code button:hover { background: #2b535e; }
.admin-code pre { overflow-x: auto; margin: 0; padding: 18px; font: 12px/1.6 var(--mono); }
.admin-code code { font: inherit; }
.reference-block { margin-top: 48px; padding-top: 25px; border-top: 2px solid #b8d1c9; }
.reference-block h3 { font: 500 27px/1.25 var(--serif); }
.reference-block h3 code { font-size: .65em; }
.reference-block > p { color: var(--muted); }
.reference-scroll { max-width: 100%; overflow-x: auto; margin: 18px 0 20px; border: 1px solid var(--line); border-radius: 5px; background: var(--white); }
.reference-table { width: 100%; min-width: 640px; border-collapse: collapse; font-size: 13px; line-height: 1.55; text-align: left; }
.reference-table.metric-table { min-width: 780px; }
.reference-table th { padding: 12px 14px; background: #e7efea; color: var(--navy); font-weight: 700; }
.reference-table td { padding: 13px 14px; border-top: 1px solid var(--line); vertical-align: top; overflow-wrap: anywhere; }
.reference-table tbody tr:nth-child(even) { background: #f7faf7; }
.reference-table td:first-child { width: 30%; color: var(--navy); font-weight: 600; }
.reference-table code { color: #24515a; font-size: .94em; }
.page-footer { display: flex; flex-wrap: wrap; gap: 14px 25px; justify-content: space-between; padding: 28px clamp(28px, 7vw, 110px); color: var(--muted); font-size: 12px; }
.copy-toast { position: fixed; z-index: 40; bottom: 25px; right: 28px; padding: 11px 17px; border-radius: 4px; background: var(--navy); color: var(--white); box-shadow: 0 8px 25px #09293240; font-size: 13px; }
.copy-toast[hidden] { display: none; }

@media (max-width: 1080px) {
  .shell { grid-template-columns: 226px minmax(0, 1fr); }
  .hero { grid-template-columns: 1fr; }
  .hero-copy { padding-bottom: 40px; }
  .signal-graphic { min-height: 180px; padding: 36px clamp(28px, 7vw, 110px); }
  .signal-line { max-width: 500px; }
  .signal-graphic ol { max-width: 520px; }
}
@media (max-width: 700px) {
  .shell { display: block; }
  .rail { position: relative; height: auto; padding: 17px 20px 12px; }
  .brand strong { font-size: 22px; }
  .rail-tools { margin-top: 20px; }
  .rail nav { display: flex; gap: 4px; overflow-x: auto; margin-top: 7px; padding-bottom: 4px; }
  .rail nav a { flex: none; padding: 8px 10px; border-left: 0; border-bottom: 2px solid transparent; white-space: nowrap; }
  .rail nav a:hover, .rail nav a.active { border-left: 0; border-bottom-color: var(--coral); }
  .rail nav em, .rail-foot { display: none; }
  .hero { min-height: 0; }
  .hero-copy { padding: 55px 25px 43px; }
  .hero-lead { font-size: 16px; }
  .signal-graphic { padding: 38px 25px; }
  .intro-grid { grid-template-columns: 1fr; gap: 26px; padding: 42px 25px 50px; }
  .chapter { padding: 60px 25px; }
  .chapter-start { padding: 0; }
  .chapter-heading { grid-template-columns: 1fr; gap: 10px; }
  .chapter-number { width: 32px; height: 32px; }
  .setup-check, .two-col { grid-template-columns: 1fr; }
  .setup-check .check-status { grid-column: 1; }
  .report-rows > div { grid-template-columns: 1fr; gap: 5px; }
  .page-footer { padding: 28px 25px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}