/* Layout concept: a shop "job traveler". Each build is a job; each step is an
   operation (OP 10, OP 20...) with a sign-off box, like a routing sheet on the floor. */
:root {
  --paper: #eceff1;        /* cool shop-paper gray */
  --sheet: #f8f9fa;        /* the traveler sheet itself */
  --ink: #18202b;          /* print */
  --muted: #5a6573;
  --rule: #c9d0d7;
  --dykem: #2747c9;        /* layout-fluid blue, the accent */
  --dykem-soft: #dfe5fb;
  --stamp: #1f7a4d;        /* sign-off / done */
  --stamp-soft: #dcefe4;
  --warn: #a8540c;         /* planned failure */
  --warn-soft: #f7e7d6;
  --code-bg: #1d2530;
  --code-fg: #e3e8ee;
  --display: "Barlow Condensed", "Arial Narrow", "Helvetica Neue", sans-serif;
  --body: "Source Serif 4", Georgia, "Times New Roman", serif;
  --mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #12161c; --sheet: #1a2028; --ink: #e6eaef; --muted: #9aa5b2; --rule: #2e3742;
    --dykem: #8aa2ff; --dykem-soft: #222c4a; --stamp: #5cc592; --stamp-soft: #17301f;
    --warn: #f0a35e; --warn-soft: #34261a; --code-bg: #0d1116; --code-fg: #dfe5ec;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font-family: var(--body); font-size: 18px; line-height: 1.6;
}
a { color: var(--dykem); text-underline-offset: 3px; }
a:focus-visible, button:focus-visible, textarea:focus-visible, input:focus-visible, summary:focus-visible {
  outline: 3px solid var(--dykem); outline-offset: 2px;
}
.wrap { max-width: 860px; margin: 0 auto; padding-inline: 20px; padding-block: 24px 64px; }

/* header */
.topbar {
  display: flex; flex-wrap: wrap; gap: 8px 16px; align-items: baseline; justify-content: space-between;
  border-bottom: 2px solid var(--ink); padding-bottom: 10px; margin-bottom: 28px;
}
.brand { font-family: var(--display); font-weight: 700; font-size: 22px; letter-spacing: .06em; text-transform: uppercase; color: var(--ink); text-decoration: none; }
.brand span { color: var(--dykem); }
.who { font-family: var(--mono); font-size: 13px; color: var(--muted); }

h1, h2, h3 { font-family: var(--display); line-height: 1.1; text-wrap: balance; margin: 0; }
h1 { font-size: clamp(40px, 7vw, 64px); font-weight: 700; letter-spacing: -.01em; }
h2 { font-size: 30px; font-weight: 700; margin-top: 8px; }
h3 { font-size: 22px; font-weight: 600; }
p { margin: 0 0 14px; }
.lede { font-size: 21px; color: var(--muted); max-width: 62ch; margin-top: 14px; }
.label { font-family: var(--mono); font-size: 12px; letter-spacing: .12em; text-transform: uppercase; color: var(--muted); }

/* the traveler sheet */
.sheet { background: var(--sheet); border: 1px solid var(--rule); border-radius: 4px; padding: 22px; }
.stack { display: grid; gap: 18px; }

/* course map rows */
.jobs { display: grid; gap: 0; border: 1px solid var(--rule); border-radius: 4px; background: var(--sheet); margin-top: 28px; }
.job {
  display: grid; grid-template-columns: 74px minmax(0, 1fr) auto; gap: 14px; align-items: center;
  padding: 16px 18px; border-top: 1px solid var(--rule); color: inherit; text-decoration: none;
}
.job:first-child { border-top: 0; }
a.job:hover { background: var(--dykem-soft); }
.job .no { font-family: var(--display); font-size: 34px; font-weight: 700; color: var(--dykem); }
.job .t { font-family: var(--display); font-size: 24px; font-weight: 600; }
.job .d { font-size: 16px; color: var(--muted); }
.job.locked .no, .job.locked .t { color: var(--muted); }
.chip { font-family: var(--mono); font-size: 12px; padding: 3px 8px; border-radius: 3px; border: 1px solid var(--rule); color: var(--muted); white-space: nowrap; }
.chip.go { border-color: var(--dykem); color: var(--dykem); }
.chip.done { border-color: var(--stamp); color: var(--stamp); background: var(--stamp-soft); }

/* lesson operations */
.op { border-top: 2px solid var(--ink); padding-top: 18px; margin-top: 40px; }
.op-head { display: flex; gap: 14px; align-items: baseline; flex-wrap: wrap; }
.op-no { font-family: var(--mono); font-size: 14px; color: var(--dykem); border: 1.5px solid var(--dykem); padding: 2px 7px; border-radius: 3px; }
.why { color: var(--muted); }
.callout { border-left: 4px solid var(--dykem); background: var(--dykem-soft); padding: 12px 16px; border-radius: 0 4px 4px 0; margin: 16px 0; }
.callout.fail { border-color: var(--warn); background: var(--warn-soft); }
.callout.mine { border-color: var(--stamp); background: var(--stamp-soft); }
.callout > :last-child { margin-bottom: 0; }
.callout .label { display: block; margin-bottom: 4px; color: inherit; opacity: .85; }
ul, ol { padding-left: 1.3em; margin: 0 0 14px; }
li { margin-bottom: 6px; }
kbd, code { font-family: var(--mono); font-size: .86em; }
:not(pre) > code { background: var(--dykem-soft); padding: 1px 5px; border-radius: 3px; overflow-wrap: anywhere; }

/* code blocks with copy */
.code { position: relative; margin: 12px 0 16px; }
pre {
  margin: 0; background: var(--code-bg); color: var(--code-fg); padding: 16px 16px; border-radius: 4px;
  overflow-x: auto; font-family: var(--mono); font-size: 14px; line-height: 1.55;
}
.code pre { padding-top: 40px; }
.copy {
  position: absolute; top: 8px; right: 8px; font-family: var(--mono); font-size: 12px;
  background: transparent; color: var(--code-fg); border: 1px solid #56606d; border-radius: 3px; padding: 3px 8px; cursor: pointer;
}
.copy:hover { border-color: var(--code-fg); }

/* Mac / Windows / Claude / ChatGPT tabs */
.tabs { margin: 12px 0 16px; }
.tablist { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 8px; }
.tablist button {
  font-family: var(--mono); font-size: 13px; padding: 6px 12px; border-radius: 3px; cursor: pointer;
  border: 1px solid var(--rule); background: var(--sheet); color: var(--ink);
}
.tablist button[aria-selected="true"] { background: var(--ink); color: var(--sheet); border-color: var(--ink); }

/* sign-off box */
.signoff { margin-top: 18px; border: 1.5px dashed var(--rule); border-radius: 4px; padding: 14px; display: grid; gap: 10px; }
.signoff.is-done { border-style: solid; border-color: var(--stamp); background: var(--stamp-soft); }
textarea, input[type="text"], input[type="password"] {
  width: 100%; font: inherit; font-size: 16px; color: var(--ink); background: var(--sheet);
  border: 1px solid var(--rule); border-radius: 3px; padding: 10px 12px;
}
textarea { min-height: 84px; resize: vertical; }
.row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.btn {
  font-family: var(--display); font-size: 18px; font-weight: 600; letter-spacing: .04em; text-transform: uppercase;
  border: 2px solid var(--ink); background: var(--ink); color: var(--sheet); padding: 7px 16px; border-radius: 3px; cursor: pointer;
}
.btn.ghost { background: transparent; color: var(--ink); }
.btn:disabled { opacity: .5; cursor: default; }
.status { font-family: var(--mono); font-size: 13px; color: var(--muted); }
.stamp { font-family: var(--mono); font-size: 13px; color: var(--stamp); font-weight: 700; letter-spacing: .08em; }

/* side progress */
.progressbar { height: 8px; background: var(--rule); border-radius: 4px; overflow: hidden; margin-top: 10px; }
.progressbar > i { display: block; height: 100%; width: 0; background: var(--stamp); transition: width .3s; }

.notice { padding: 12px 16px; border: 1px solid var(--warn); background: var(--warn-soft); border-radius: 4px; margin-bottom: 20px; }
.qa { border-top: 1px solid var(--rule); padding-top: 12px; margin-top: 12px; }
.qa .a { border-left: 3px solid var(--stamp); padding-left: 12px; margin-top: 6px; white-space: pre-wrap; }
footer { margin-top: 56px; padding-top: 14px; border-top: 1px solid var(--rule); font-size: 14px; color: var(--muted); }

table { border-collapse: collapse; width: 100%; font-size: 15px; }
th, td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { font-family: var(--mono); font-size: 12px; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.scroll { overflow-x: auto; }

@media (max-width: 560px) {
  body { font-size: 17px; }
  .job { grid-template-columns: 52px minmax(0, 1fr); }
  .job .chip { grid-column: 2; justify-self: start; }
  .job .no { font-size: 28px; }
  .sheet { padding: 16px; }
  pre { white-space: pre-wrap; overflow-wrap: anywhere; font-size: 13px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }