:root {
  color-scheme: light;
  --paper: #f6f5f0;
  --card: #fffefa;
  --ink: #262d2a;
  --muted: #61685f;
  --line: #dcded3;
  --green: #325c43;
  --soft-green: #e8edde;
  --orange: #a64b2b;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 35px; }
body { margin: 0; color: var(--ink); background: var(--paper); font: 16px/1.65 var(--sans); }
button, input, select { font: inherit; }
button, a, input, select, summary { -webkit-tap-highlight-color: transparent; }
a { color: var(--green); text-underline-offset: 4px; }
a:hover { color: var(--orange); }
button { cursor: pointer; }
button:disabled { cursor: default; opacity: .6; }
:focus-visible { outline: 3px solid var(--orange); outline-offset: 5px; }
[hidden] { display: none !important; }
.wrap { width: min(1180px, calc(100% - 80px)); margin-inline: auto; }
.site-header { min-height: 102px; border-bottom: 1px solid var(--line); display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.brand { display: inline-flex; align-items: center; gap: 9px; font-size: 29px; font-weight: 750; letter-spacing: -1.4px; text-decoration: none; color: var(--ink); }
.brand img { object-fit: contain; }
.brand-dot { color: var(--orange); }
.header-label, .tiny-label, .eyebrow, .lesson-kicker, .meta-line, .visual-label, .file-tag, .simulation-heading, .check-label, .command-heading, .pill { font-family: var(--mono); font-weight: 500; }
.header-label { font-size: 11px; letter-spacing: 2px; color: var(--muted); }
.source-link { font-size: 13px; color: var(--ink); text-decoration: none; }
.source-link span { margin-left: 14px; }
.hero { display: grid; grid-template-columns: 1.3fr 1fr; align-items: center; gap: 62px; padding: 76px 0 82px; }
.eyebrow { font-size: 10px; letter-spacing: 1.4px; margin: 0 0 25px; color: var(--green); display: flex; align-items: center; gap: 10px; }
.status-dot { display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: #648149; flex-shrink: 0; }
h1 { font-size: clamp(46px, 5.4vw, 69px); line-height: 1.08; font-weight: 560; letter-spacing: -3.2px; margin: 0 0 25px; }
.serif { font-family: Georgia, "Times New Roman", serif; font-style: italic; font-weight: 400; color: var(--green); }
.lede { max-width: 470px; font-size: 19px; line-height: 1.6; margin: 0 0 17px; }
.hero-description { font-size: 14px; color: var(--muted); margin: 0; }
.hero-actions { display: flex; align-items: center; gap: 27px; margin: 29px 0 22px; }
.button { padding: 12px 19px; border-radius: 5px; display: inline-flex; gap: 30px; align-items: center; text-decoration: none; font-size: 13px; font-weight: 650; }
.primary { color: #fff; background: var(--green); border: 1px solid var(--green); }
.primary:hover { background: #254832; color: #fff; }
.text-link { font-size: 13px; font-weight: 650; text-decoration: none; }
.meta-line { font-size: 10px; color: var(--muted); display: flex; gap: 8px; flex-wrap: wrap; }
.hero-visual { padding: 30px 25px 22px; background: #eceee3; border: 1px solid #e1e4d7; border-radius: 9px; transform: rotate(1deg); }
.visual-label { display: flex; align-items: center; justify-content: center; gap: 8px; color: #57634e; font-size: 9px; letter-spacing: .6px; margin-bottom: 22px; }
.file-card { background: var(--card); border: 1px solid #d1d7c8; border-radius: 6px; box-shadow: 0 6px 0 -2px #e1e4d9, 0 9px 0 -2px #cdd4c5, 0 16px 25px #29372508; transform: rotate(-2deg); }
.file-heading { display: flex; align-items: center; padding: 13px 18px; border-bottom: 1px solid var(--line); font: 11px var(--mono); gap: 9px; }
.file-icon { color: var(--green); font-size: 20px; line-height: 1; }
.file-tag { margin-left: auto; font-size: 9px; color: var(--muted); }
.file-body { padding: 25px 23px 23px; }
.tiny-label { font-size: 10px; letter-spacing: 1px; color: var(--muted); }
.file-body h2 { font-size: 17px; letter-spacing: -.4px; font-weight: 650; margin: 7px 0 20px; }
.example-check, .example-open { font: 11px/1.7 var(--mono); margin: 8px 0; }
.example-check { color: var(--green); }
.example-open { color: var(--muted); }
.example-check span, .example-open span { display: inline-block; width: 24px; }
.next-note { margin-top: 25px; padding: 12px 14px; border-left: 2px solid #9aa880; background: #f0f2e9; }
.next-note > span { font: 9px var(--mono); color: var(--green); letter-spacing: 1px; }
.next-note p { font-size: 12px; line-height: 1.6; margin: 5px 0 0; }
.session-thread { display: flex; align-items: center; gap: 10px; margin: 30px 10px 0; font: 10px var(--mono); color: var(--green); }
.thread-line { flex: 1; height: 1px; background: #b9c4aa; }
.visual-caption { font: 10px var(--mono); text-align: center; color: var(--muted); margin: 17px 0 0; }
.guide-layout { display: grid; grid-template-columns: 230px minmax(0, 1fr); gap: 72px; border-top: 1px solid var(--line); }
.guide-nav { position: sticky; top: 32px; align-self: start; padding: 37px 0; }
.guide-nav > .tiny-label { font-size: 9px; margin: 0 0 21px; }
.guide-nav nav { display: grid; gap: 6px; }
.guide-nav nav a { display: flex; align-items: center; gap: 13px; padding: 10px 12px; font-size: 12px; border-left: 2px solid transparent; text-decoration: none; color: var(--muted); }
.guide-nav nav a span { font: 10px var(--mono); opacity: .75; }
.guide-nav nav a:hover { background: #eef0e6; color: var(--ink); }
.guide-nav nav a[aria-current] { background: var(--soft-green); border-left-color: var(--green); color: var(--green); font-weight: 650; }
.nav-note { display: flex; gap: 10px; border-top: 1px solid var(--line); padding-top: 23px; margin-top: 27px; color: var(--muted); }
.nav-note p { font-size: 11px; line-height: 1.9; margin: 0; }
.small-file { color: var(--green); }
.help-link { display: block; font-size: 11px; margin-top: 25px; text-decoration: none; }
.lessons { min-width: 0; }
.lesson { padding: 41px 0 48px; border-bottom: 1px solid var(--line); scroll-margin-top: 14px; }
.lesson-kicker { display: flex; align-items: center; gap: 14px; justify-content: space-between; font-size: 10px; letter-spacing: 1.2px; color: var(--green); margin: 0 0 21px; }
.pill { font-size: 8px; letter-spacing: .7px; background: #eceee5; color: var(--muted); border-radius: 3px; padding: 3px 7px; white-space: nowrap; }
.pill.accent { color: var(--orange); background: #f2e7dc; }
.lesson h2 { font-size: clamp(28px, 3vw, 36px); line-height: 1.2; letter-spacing: -1.1px; margin: 0 0 20px; font-weight: 580; }
.lesson > p { font-size: 14px; color: var(--muted); margin: 15px 0 20px; }
.lesson strong { color: var(--ink); font-weight: 650; }
code { font: .89em/1.6 var(--mono); overflow-wrap: anywhere; }
p code, li code, td code { background: #e9ece2; color: #364f3f; padding: 2px 4px; border-radius: 3px; }
.selector { border: 0; margin: 25px 0 17px; padding: 0; min-width: 0; }
.selector legend { font-size: 12px; font-weight: 650; margin-bottom: 10px; }
.segmented { display: flex; flex-wrap: wrap; gap: 5px; background: #eceee5; border: 1px solid var(--line); padding: 4px; border-radius: 6px; width: fit-content; max-width: 100%; }
.segmented label { position: relative; cursor: pointer; }
.segmented input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.segmented span { display: block; padding: 7px 13px; border: 1px solid transparent; border-radius: 3px; font-size: 12px; color: var(--muted); }
.segmented input:checked + span { background: var(--card); border-color: #d3d8c8; color: var(--green); box-shadow: 0 1px 2px #2633260a; }
.segmented input:focus-visible + span { outline: 2px solid var(--orange); outline-offset: 1px; }
.command-box { border: 1px solid #323e35; background: #27342c; color: #eef2e6; border-radius: 6px; overflow: hidden; margin: 19px 0 12px; }
.command-heading { display: flex; justify-content: space-between; align-items: center; gap: 12px; min-height: 40px; padding: 6px 16px; border-bottom: 1px solid #445044; font-size: 9px; letter-spacing: .65px; color: #c4cfbc; }
.copy { color: #e1e8d9; background: transparent; border: 1px solid #59694e; border-radius: 4px; padding: 4px 8px; font: 10px/1.4 var(--mono); white-space: nowrap; }
.copy:hover:not(:disabled) { background: #43523a; }
.copy:focus-visible { outline-color: #e6ba87; }
.command-box pre { white-space: pre-wrap; overflow-wrap: anywhere; margin: 0; padding: 20px; font: 12px/1.9 var(--mono); }
.command-box pre code { font: inherit; }
.prompt-box { background: #fdfdf7; border-color: var(--line); color: #3a473a; }
.prompt-box .command-heading { border-color: var(--line); color: var(--muted); background: #eef0e6; }
.prompt-box .copy { color: var(--green); border-color: #ccd3c1; }
.prompt-box .copy:hover:not(:disabled) { background: #dfe5d3; }
.prompt-box .copy:focus-visible { outline-color: var(--orange); }
.small-note, .lesson > .small-note { font-size: 12px; line-height: 1.7; color: var(--muted); margin: 10px 0 20px; }
.checkpoint { border-left: 2px solid #92a574; padding: 13px 18px; margin: 25px 0 0; background: #ecefe3; }
.check-label { font-size: 9px; letter-spacing: 1px; color: var(--green); }
.checkpoint p { color: #4a5943; font-size: 13px; line-height: 1.7; margin: 6px 0 0; }
details { border-top: 1px solid var(--line); margin-top: 20px; font-size: 13px; }
summary { cursor: pointer; padding: 15px 0; color: var(--ink); font-weight: 550; }
summary::marker { color: #78866a; }
details p { color: var(--muted); margin: 0 0 17px; }
details ol { color: var(--muted); padding-left: 22px; margin-top: 0; }
details li { padding-left: 3px; margin: 10px 0; }
.simulation { background: var(--card); border: 1px solid #cfd6c4; border-radius: 8px; margin: 27px 0; overflow: hidden; }
.simulation-heading { display: flex; align-items: center; justify-content: space-between; gap: 15px; padding: 13px 19px; background: #e9edde; color: #546248; font-size: 8px; letter-spacing: .5px; flex-wrap: wrap; }
.simulation-heading > span:first-child { display: flex; align-items: center; gap: 8px; }
.scene-buttons { display: flex; padding: 15px 18px; gap: 7px; border-bottom: 1px solid var(--line); }
.scene-buttons button { flex: 1; border: 1px solid var(--line); background: transparent; color: var(--muted); padding: 9px 5px; font-size: 12px; border-radius: 4px; }
.scene-buttons button > span { font: 10px var(--mono); margin-right: 9px; }
.scene-buttons button[aria-pressed="true"] { border-color: var(--green); color: var(--green); background: var(--soft-green); font-weight: 650; }
.scene-buttons button:hover { border-color: var(--green); }
.simulation-content { padding: 0 22px 20px; }
.example-stats { display: grid; grid-template-columns: 1fr 1fr 1fr; padding: 18px 0; border-bottom: 1px dashed var(--line); gap: 13px; }
.example-stats > div > span { display: block; font: 8px var(--mono); letter-spacing: .7px; color: var(--muted); }
.example-stats strong { display: block; margin-top: 5px; font: 13px var(--mono); }
.example-task { padding: 18px 0 14px; }
.example-task-heading { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.example-task h3 { font-size: 14px; margin: 0; }
.task-badge { margin-left: auto; font: 9px var(--mono); padding: 3px 6px; background: #eceee5; border-radius: 3px; color: var(--muted); white-space: nowrap; }
.example-task > p { margin: 9px 0; font: 11px/1.8 var(--mono); color: var(--muted); }
.example-task > p > span { margin-right: 9px; }
.example-task .done { color: var(--green); }
.example-evidence { background: #eff1e8; border-radius: 4px; padding: 13px 15px; min-height: 101px; }
.example-evidence .tiny-label { font-size: 8px; }
.example-evidence p { margin: 6px 0 0; font-size: 12px; color: #4c5945; }
.scene-lesson { font-size: 12px; color: var(--green); margin: 17px 0 0; min-height: 40px; }
.knowledge-check { margin-top: 25px; }
.knowledge-check h3 { font-size: 15px; margin: 0; }
.knowledge-check p { color: var(--muted); font-size: 13px; margin: 6px 0 13px; }
.answer-options { display: grid; gap: 7px; }
.answer-options button { padding: 11px 15px; text-align: left; font-size: 12px; border: 1px solid var(--line); border-radius: 4px; background: var(--card); color: var(--ink); }
.answer-options button:hover { border-color: var(--green); }
.answer-options button[aria-pressed="true"] { background: var(--soft-green); border-color: var(--green); }
.answer-feedback { min-height: 44px; }
.knowledge-check .answer-feedback.correct { color: var(--green); }
.table-scroll { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; margin-bottom: 20px; text-align: left; font-size: 12px; }
caption { text-align: left; color: var(--muted); padding-bottom: 10px; font-size: 11px; }
th, td { padding: 10px; border-bottom: 1px solid var(--line); }
th { font-weight: 550; }
.substep { display: flex; align-items: center; gap: 12px; margin: 30px 0 12px; font-size: 16px; }
.substep span { font: 10px var(--mono); display: grid; place-items: center; width: 24px; height: 24px; border: 1px solid #cad2bf; color: var(--green); border-radius: 50%; }
.field { margin: 20px 0 0; }
.field label { display: block; margin-bottom: 8px; font-size: 12px; font-weight: 650; }
.field input, .field select { width: 100%; max-width: 100%; padding: 12px 14px; background: var(--card); border: 1px solid #c6cdbe; border-radius: 4px; font: 12px var(--mono); color: var(--ink); }
.field input[aria-invalid="true"] { border-color: var(--orange); }
.field .small-note { margin: 7px 0; font-size: 11px; }
.field-error { font-size: 12px; color: var(--orange); margin: 0; }
.field-error:empty { display: none; }
kbd { font: 11px var(--mono); padding: 2px 6px; border: 1px solid #c6cdbe; border-radius: 4px; background: var(--card); box-shadow: 0 2px 0 #d8ddce; white-space: nowrap; }
.shortcut-card { display: flex; align-items: center; gap: 28px; padding: 22px; border: 1px solid var(--line); background: #eeefe6; border-radius: 6px; margin-top: 23px; }
.keycaps { display: flex; align-items: center; gap: 8px; }
.keycaps kbd { font-size: 14px; padding: 10px 11px; }
.keycaps > span { color: #829173; font-size: 10px; }
.shortcut-card p { font-size: 11px; line-height: 1.8; color: var(--muted); margin: 0; }
.verify-choice { border: 0; padding: 0; margin: 25px 0 12px; }
.verify-choice legend { font-size: 13px; font-weight: 650; margin-bottom: 11px; }
.verify-choice label { display: block; font-size: 12px; color: var(--muted); margin: 9px 0; cursor: pointer; }
.verify-choice input { accent-color: var(--green); margin-right: 8px; }
.lesson > .verify-feedback { font-size: 12px; padding: 12px 15px; background: #eceee5; border-radius: 4px; }
.lesson > .verify-feedback.success { color: var(--green); background: #e2ecd8; }
.key-reference { border-top: 1px solid var(--line); margin-top: 28px; padding-top: 21px; }
.key-reference h3 { font-size: 13px; font-weight: 600; margin: 0; }
.key-reference dl { display: grid; grid-template-columns: 1fr 1fr; gap: 14px 18px; margin: 17px 0 0; }
.key-reference dl > div { display: flex; gap: 12px; align-items: center; }
.key-reference dt { min-width: 45px; }
.key-reference dd { margin: 0; font-size: 11px; color: var(--muted); }
.finish-card { padding: 27px; margin-top: 30px; background: #e7edde; border: 1px solid #d0dac3; border-radius: 6px; }
.finish-card .tiny-label { font-size: 9px; color: var(--green); }
.finish-card h3 { font-size: 23px; line-height: 1.3; font-weight: 550; letter-spacing: -.6px; margin: 12px 0; max-width: 410px; }
.finish-card p { color: #58664e; font-size: 13px; margin: 0 0 18px; }
.troubleshooting { border-bottom: none; }
.troubleshooting h2 { font-size: 29px; }
.troubleshooting details { margin-top: 0; }
.troubleshooting summary { padding: 18px 0; }
.site-footer { border-top: 1px solid var(--line); min-height: 110px; display: flex; align-items: center; gap: 25px; justify-content: space-between; }
.site-footer .brand { font-size: 22px; gap: 0; }
.site-footer p { font-size: 11px; color: var(--muted); }
.site-footer > a:last-child { font-size: 11px; text-decoration: none; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link { position: fixed; top: -100px; left: 15px; padding: 10px 16px; background: var(--card); z-index: 10; }
.skip-link:focus { top: 15px; }
.noscript-note { padding: 20px; margin: 0; text-align: center; background: #e9edde; font-size: 13px; }
@media (min-width: 1500px) { .hero { gap: 95px; } }
@media (max-width: 1000px) {
  .wrap { width: calc(100% - 48px); }
  .hero { gap: 35px; grid-template-columns: 1.2fr 1fr; }
  h1 { font-size: 53px; }
  .hero-visual { padding: 25px 15px 20px; }
  .guide-layout { gap: 35px; grid-template-columns: 195px minmax(0, 1fr); }
  .file-body { padding: 20px 17px; }
  .shortcut-card { align-items: flex-start; flex-direction: column; gap: 18px; }
  .desktop-break { display: none; }
}
@media (max-width: 760px) {
  html { scroll-padding-top: 20px; }
  .wrap { width: calc(100% - 36px); }
  .site-header { min-height: 78px; }
  .header-label { display: none; }
  .brand { font-size: 26px; }
  .brand img { width: 33px; }
  .hero { grid-template-columns: 1fr; padding: 45px 0; gap: 34px; }
  h1 { font-size: clamp(46px, 9vw, 66px); letter-spacing: -2.4px; }
  .eyebrow { font-size: 9px; margin-bottom: 21px; }
  .lede { font-size: 18px; }
  .hero-description { font-size: 13px; }
  .hero-visual { max-width: 440px; width: calc(100% - 12px); justify-self: center; padding: 23px 25px 19px; }
  .guide-layout { grid-template-columns: 1fr; gap: 0; }
  .guide-nav { position: static; padding: 22px 0; border-bottom: 1px solid var(--line); }
  .guide-nav > .tiny-label { margin-bottom: 13px; }
  .guide-nav nav { grid-template-columns: 1fr 1fr; gap: 2px; }
  .guide-nav nav a { padding: 9px 7px; gap: 9px; font-size: 11px; }
  .nav-note { display: none; }
  .help-link { margin-top: 13px; }
  .lesson { padding: 33px 0 35px; }
  .lesson h2 { font-size: 30px; }
  .lesson-kicker { margin-bottom: 17px; font-size: 9px; letter-spacing: .8px; }
  .lesson > p { font-size: 14px; }
  .segmented span { padding: 7px 10px; font-size: 11px; }
  .command-heading { padding: 7px 12px; font-size: 8px; gap: 8px; }
  .command-box pre { padding: 17px 14px; font-size: 11px; }
  .checkpoint { padding: 12px 15px; }
  .checkpoint p { font-size: 12px; }
  .simulation-heading { padding: 12px 15px; font-size: 7px; gap: 8px; }
  .simulation-content { padding: 0 15px 16px; }
  .scene-buttons { padding: 12px; }
  .scene-buttons button { font-size: 11px; }
  .scene-buttons button > span { margin-right: 4px; }
  .example-stats { gap: 8px; }
  .example-stats strong { font-size: 11px; }
  .example-stats > div > span { font-size: 7px; }
  .example-task h3 { font-size: 12px; }
  .example-task > p { font-size: 10px; }
  .key-reference dl { gap: 14px 8px; }
  .key-reference dl > div { gap: 7px; }
  .key-reference dd { font-size: 10px; }
  .finish-card { padding: 23px 20px; }
  .site-footer { flex-wrap: wrap; justify-content: flex-start; gap: 12px 20px; padding: 24px 0; }
  .site-footer p { flex: 1; margin: 0; }
  .site-footer > a:last-child { flex-basis: 100%; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
@media print {
  body { background: white; font-size: 11pt; }
  .wrap { width: 100%; }
  .hero { padding: 25px 0; }
  .guide-layout { display: block; }
  .guide-nav, .copy, .hero-actions, .site-footer, .knowledge-check, .verify-choice, .verify-feedback { display: none; }
  .lesson { break-inside: avoid; }
  .command-box { background: #f3f4ed; color: #263326; }
  .command-heading { color: #263326; }
  details > * { display: block !important; }
}