/* Semantic Layer mini course. Light and dark, no framework. */

:root {
  --bg: #fbfaf8;
  --bg-raised: #ffffff;
  --bg-sunk: #f2f0ec;
  --ink: #1c1a17;
  --ink-soft: #56514a;
  --ink-faint: #8a837a;
  --line: #e2ded6;
  --line-strong: #cdc7bc;

  --accent: #1f6f6b;
  --accent-soft: #e6f2f1;
  --accent-ink: #14504d;

  --amber: #a86a1a;
  --amber-soft: #fdf3e2;
  --violet: #6b4fa8;
  --violet-soft: #f0ebfa;
  --rose: #a83e4f;
  --rose-soft: #fbeaec;
  --aws: #c26a12;
  --aws-soft: #fdf1e3;
  --oss: #3d6fa8;
  --oss-soft: #eaf1fa;

  --ok: #2f7d4f;
  --ok-soft: #e8f4ec;
  --bad: #b3382f;
  --bad-soft: #fbeceb;

  --radius: 10px;
  --radius-sm: 6px;
  --shadow: 0 1px 2px rgba(28, 26, 23, .05), 0 4px 16px rgba(28, 26, 23, .05);
  --shadow-lift: 0 2px 6px rgba(28, 26, 23, .08), 0 12px 32px rgba(28, 26, 23, .09);

  --sans: ui-sans-serif, -apple-system, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --serif: ui-serif, Georgia, "Times New Roman", serif;

  --wrap: 1180px;
  --read: 68ch;
  color-scheme: light;
}

/* Dark tokens for the system default. Guarded so an explicit light choice
   still wins. Written as a top-level media query rather than CSS nesting,
   because a nested at-rule here is not universally supported and would
   invalidate the rest of the sheet. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #14150f;
    --bg-raised: #1c1e17;
    --bg-sunk: #101109;
    --ink: #ece8df;
    --ink-soft: #b3ada1;
    --ink-faint: #837d72;
    --line: #2d2f26;
    --line-strong: #3f4237;
    --accent: #6dc0b8;
    --accent-soft: #17322f;
    --accent-ink: #a8ddd7;
    --amber: #e0a656;
    --amber-soft: #33260f;
    --violet: #b39ee0;
    --violet-soft: #241f33;
    --rose: #e08e9a;
    --rose-soft: #331d21;
    --aws: #e8a35c;
    --aws-soft: #33240f;
    --oss: #8db4e0;
    --oss-soft: #17222f;
    --ok: #74c091;
    --ok-soft: #16301f;
    --bad: #e08b83;
    --bad-soft: #331b19;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 4px 16px rgba(0, 0, 0, .25);
    --shadow-lift: 0 2px 6px rgba(0, 0, 0, .35), 0 12px 32px rgba(0, 0, 0, .4);
    color-scheme: dark;
  }
}

[data-theme="dark"] {
  --bg: #14150f;
  --bg-raised: #1c1e17;
  --bg-sunk: #101109;
  --ink: #ece8df;
  --ink-soft: #b3ada1;
  --ink-faint: #837d72;
  --line: #2d2f26;
  --line-strong: #3f4237;

  --accent: #6dc0b8;
  --accent-soft: #17322f;
  --accent-ink: #a8ddd7;

  --amber: #e0a656;
  --amber-soft: #33260f;
  --violet: #b39ee0;
  --violet-soft: #241f33;
  --rose: #e08e9a;
  --rose-soft: #331d21;
  --aws: #e8a35c;
  --aws-soft: #33240f;
  --oss: #8db4e0;
  --oss-soft: #17222f;

  --ok: #74c091;
  --ok-soft: #16301f;
  --bad: #e08b83;
  --bad-soft: #331b19;

  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 4px 16px rgba(0, 0, 0, .25);
  --shadow-lift: 0 2px 6px rgba(0, 0, 0, .35), 0 12px 32px rgba(0, 0, 0, .4);
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 5rem; }

body {
  margin: 0;
  overflow-x: hidden;   /* a stray wide child must not scroll the page */
  background: var(--bg);
  color: var(--ink);
  font: 400 16px/1.65 var(--sans);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; }
[hidden] { display: none !important; }

a { color: var(--accent-ink); text-decoration-color: var(--line-strong); text-underline-offset: 2px; }
a:hover { text-decoration-color: currentColor; }

h1, h2, h3, h4 { line-height: 1.2; letter-spacing: -.012em; margin: 0 0 .5rem; font-weight: 650; }
h1 { font-size: clamp(1.75rem, 1.2rem + 2vw, 2.6rem); }
h2 { font-size: clamp(1.3rem, 1.1rem + 1vw, 1.65rem); }
h3 { font-size: 1.1rem; }
p { margin: 0 0 1rem; }

code, kbd, pre { font-family: var(--mono); }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 3px; }

.wrap { width: 100%; max-width: var(--wrap); margin-inline: auto; padding-inline: 20px; }
.stack > * + * { margin-top: var(--gap, 1rem); }

/* ---------- top bar ---------- */

.topbar {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.topbar-in {
  display: flex; align-items: center; gap: 1rem;
  min-height: 58px;
}
.brand {
  display: flex; align-items: center; gap: .55rem;
  font-weight: 650; letter-spacing: -.02em; color: var(--ink);
  text-decoration: none; font-size: .98rem; flex: none;
}
.brand-mark {
  width: 26px; height: 26px; flex: none;
}
.topnav { display: flex; gap: .25rem; margin-left: auto; align-items: center; }
.topnav a {
  padding: .4rem .7rem; border-radius: var(--radius-sm);
  font-size: .875rem; color: var(--ink-soft); text-decoration: none; font-weight: 500;
}
.topnav a:hover { background: var(--bg-sunk); color: var(--ink); }
.topnav a.on { background: var(--accent-soft); color: var(--accent-ink); }

.iconbtn {
  display: inline-grid; place-items: center;
  width: 34px; height: 34px; padding: 0;
  border: 1px solid var(--line); border-radius: var(--radius-sm);
  background: var(--bg-raised); color: var(--ink-soft); cursor: pointer;
}
.iconbtn:hover { border-color: var(--line-strong); color: var(--ink); }

.whoami {
  display: flex; align-items: center; gap: .5rem;
  font-size: .85rem; color: var(--ink-soft);
}
.avatar {
  width: 28px; height: 28px; border-radius: 50%;
  display: grid; place-items: center; flex: none;
  background: var(--accent-soft); color: var(--accent-ink);
  font-weight: 650; font-size: .8rem; letter-spacing: -.02em;
}

/* ---------- buttons ---------- */

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .45rem;
  padding: .55rem 1rem; border-radius: var(--radius-sm);
  border: 1px solid var(--line-strong); background: var(--bg-raised); color: var(--ink);
  font: 550 .9rem/1 var(--sans); cursor: pointer; text-decoration: none;
  transition: background .12s, border-color .12s, transform .06s;
}
.btn:hover { border-color: var(--ink-faint); }
.btn:active { transform: translateY(1px); }
.btn-primary {
  background: var(--accent); border-color: var(--accent); color: #fff;
}
/* On a dark ground the accent is light, so the label must go dark. */
[data-theme="dark"] .btn-primary { color: #0d1512; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .btn-primary { color: #0d1512; }
}
.btn-primary:hover { background: var(--accent-ink); border-color: var(--accent-ink); }
.btn-ghost { background: transparent; border-color: transparent; color: var(--ink-soft); }
.btn-ghost:hover { background: var(--bg-sunk); color: var(--ink); }
.btn-sm { padding: .35rem .7rem; font-size: .82rem; }
.btn:disabled { opacity: .5; cursor: not-allowed; }

/* ---------- hero ---------- */

.hero { padding-block: clamp(2rem, 5vw, 3.5rem) 1.5rem; }
.hero-grid {
  display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  gap: clamp(1.5rem, 4vw, 3rem); align-items: center;
}
.eyebrow {
  display: inline-flex; align-items: center; gap: .5rem;
  font: 600 .75rem/1 var(--sans); letter-spacing: .07em; text-transform: uppercase;
  color: var(--accent-ink); background: var(--accent-soft);
  padding: .4rem .7rem; border-radius: 100px; margin-bottom: .9rem;
}
.hero p.lede { font-size: 1.08rem; color: var(--ink-soft); max-width: 56ch; }
.hero-cta { display: flex; flex-wrap: wrap; gap: .6rem; margin-top: 1.4rem; align-items: center; }
.hero-facts { display: flex; flex-wrap: wrap; gap: 1.5rem; margin-top: 1.6rem; }
.fact .n { font: 650 1.5rem/1 var(--sans); letter-spacing: -.02em; }
.fact .l { font-size: .78rem; color: var(--ink-faint); text-transform: uppercase; letter-spacing: .06em; }

/* ---------- cards ---------- */

.card {
  background: var(--bg-raised); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow);
}
.card-pad { padding: 1.15rem 1.25rem; }

.modgrid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1rem;
}
.modcard {
  display: flex; flex-direction: column; gap: .6rem;
  padding: 1.1rem 1.15rem 1rem;
  background: var(--bg-raised); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow);
  text-decoration: none; color: inherit; position: relative; overflow: hidden;
  transition: transform .14s, box-shadow .14s, border-color .14s;
}
.modcard::before {
  content: ""; position: absolute; inset: 0 auto 0 0; width: 3px;
  background: var(--layer-color, var(--line-strong));
}
.modcard:hover { transform: translateY(-2px); box-shadow: var(--shadow-lift); border-color: var(--line-strong); }
.modcard[data-done="1"] { border-color: color-mix(in srgb, var(--ok) 40%, var(--line)); }

.modcard-top { display: flex; align-items: flex-start; gap: .7rem; }
.modnum {
  flex: none; width: 30px; height: 30px; border-radius: 8px;
  display: grid; place-items: center;
  background: var(--bg-sunk); color: var(--ink-soft);
  font: 650 .85rem/1 var(--mono);
}
.modcard[data-done="1"] .modnum { background: var(--ok-soft); color: var(--ok); }
.modcard h3 { margin: 0; font-size: 1.02rem; }
.modcard .sub { color: var(--ink-soft); font-size: .875rem; margin: .15rem 0 0; }
.modcard .blurb { color: var(--ink-soft); font-size: .86rem; margin: 0; }

.chips { display: flex; flex-wrap: wrap; gap: .35rem; align-items: center; }
.chip {
  font: 550 .72rem/1 var(--sans); letter-spacing: .01em;
  padding: .3rem .55rem; border-radius: 100px;
  background: var(--bg-sunk); color: var(--ink-soft); white-space: nowrap;
}
.chip-layer { background: var(--layer-soft, var(--bg-sunk)); color: var(--layer-color, var(--ink-soft)); }
.chip-ok { background: var(--ok-soft); color: var(--ok); }
.chip-lab { background: var(--violet-soft); color: var(--violet); }
.chip-ace { background: var(--accent-soft); color: var(--accent-ink); }

/* layer colors, applied via data-layer */
[data-layer*="Foundation"]   { --layer-color: var(--ink-soft);  --layer-soft: var(--bg-sunk); }
[data-layer*="Data"]         { --layer-color: var(--oss);       --layer-soft: var(--oss-soft); }
[data-layer*="Knowledge"]    { --layer-color: var(--accent);    --layer-soft: var(--accent-soft); }
[data-layer*="Intelligence"] { --layer-color: var(--violet);    --layer-soft: var(--violet-soft); }
[data-layer*="Orchestration"]{ --layer-color: var(--amber);     --layer-soft: var(--amber-soft); }
[data-layer*="Interface"]    { --layer-color: var(--rose);      --layer-soft: var(--rose-soft); }

/* ---------- progress bars ---------- */

.bar {
  height: 6px; border-radius: 100px; background: var(--bg-sunk); overflow: hidden;
}
.bar > i {
  display: block; height: 100%; border-radius: 100px;
  background: var(--accent); transition: width .4s cubic-bezier(.2,.8,.2,1);
}
.bar.done > i { background: var(--ok); }
.bar-lg { height: 9px; }

.ring { --p: 0; width: 92px; height: 92px; flex: none; position: relative; }
.ring svg { transform: rotate(-90deg); }
.ring .track { stroke: var(--bg-sunk); }
.ring .fill {
  stroke: var(--accent); stroke-linecap: round;
  transition: stroke-dashoffset .6s cubic-bezier(.2,.8,.2,1);
}
.ring .lbl {
  position: absolute; inset: 0; display: grid; place-items: center;
  font: 650 1.1rem/1 var(--sans); letter-spacing: -.02em;
}

/* ---------- module page layout ---------- */

.modlayout {
  display: grid; grid-template-columns: 250px minmax(0, 1fr);
  gap: 2.5rem; align-items: start;
  /* min-width:0 on the grid itself stops a wide child (a long TOC row, a
     code block) from inflating the whole track. */
  min-width: 0;
  padding-block: 1.75rem 4rem;
}
.rail { position: sticky; top: 74px; }
.rail-head {
  font: 600 .72rem/1 var(--sans); letter-spacing: .08em; text-transform: uppercase;
  color: var(--ink-faint); margin-bottom: .6rem;
}
.toc { list-style: none; margin: 0 0 1.5rem; padding: 0; }
.toc li { margin: 0; }
.toc a {
  display: flex; gap: .55rem; align-items: baseline;
  padding: .4rem .6rem; border-radius: var(--radius-sm);
  font-size: .875rem; color: var(--ink-soft); text-decoration: none;
  border-left: 2px solid transparent;
}
.toc a:hover { background: var(--bg-sunk); color: var(--ink); }
.toc a.on { color: var(--accent-ink); border-left-color: var(--accent); background: var(--accent-soft); }
.toc .tick { flex: none; width: 14px; color: var(--ok); opacity: 0; transition: opacity .2s; }
.toc a[data-read="1"] .tick { opacity: 1; }

.modhead { padding-block: 1.5rem .5rem; border-bottom: 1px solid var(--line); }
.modhead h1 { margin-bottom: .3rem; }
.modhead .sub { font-size: 1.05rem; color: var(--ink-soft); margin: 0 0 .9rem; }

article.body { max-width: var(--read); }
article.body h2 { margin-top: 0; }

section.sec { padding-block: 2.25rem; border-bottom: 1px solid var(--line); }
section.sec:last-of-type { border-bottom: 0; }
.sec-num {
  font: 600 .72rem/1 var(--mono); letter-spacing: .08em;
  color: var(--ink-faint); text-transform: uppercase; margin-bottom: .5rem; display: block;
}

.sec-foot { margin-top: 1.5rem; display: flex; align-items: center; gap: .75rem; flex-wrap: wrap; }

/* ---------- content blocks ---------- */

blockquote.pull {
  margin: 1.5rem 0; padding: .25rem 0 .25rem 1.25rem;
  border-left: 3px solid var(--accent);
  font: 400 1.2rem/1.5 var(--serif); color: var(--ink);
}
blockquote.pull cite { display: block; font: 500 .85rem/1.4 var(--sans); color: var(--ink-faint); margin-top: .5rem; font-style: normal; }

figure { margin: 1.5rem 0; }
figcaption {
  font-size: .82rem; color: var(--ink-faint); margin-top: .5rem; line-height: 1.5;
}

.codewrap { position: relative; margin: 1.35rem 0; }
.codewrap .lang {
  position: absolute; top: 0; right: 0;
  font: 600 .68rem/1 var(--mono); letter-spacing: .06em; text-transform: uppercase;
  color: var(--ink-faint); padding: .5rem .6rem;
}
.codewrap .copy {
  position: absolute; top: .35rem; right: .35rem; opacity: 0;
  transition: opacity .15s;
}
.codewrap:hover .copy { opacity: 1; }
.codewrap:hover .lang { opacity: 0; }
pre {
  margin: 0; padding: .95rem 1.05rem;
  background: var(--bg-sunk); border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  font-size: .845rem; line-height: 1.6;
  /* overflow-x alone is not enough: inside a flex or grid child a pre still
     grows to its content width unless min-width is allowed to go to zero. */
  overflow-x: auto;
  min-width: 0; max-width: 100%;
}
/* Widget bodies build their own markup, often nesting a plain div inside a
   grid cell. A grid or flex item defaults to min-width:auto, which refuses to
   shrink below its content, so a wide code block pushes the page out. Reach
   every descendant inside a widget rather than only direct children. */
.widget, .widget * { min-width: 0; }
.widget-body, .widget-body *, .reveal, .reveal * { max-width: 100%; }
.sec-body, .sec-body > * { min-width: 0; }
/* Grid and flex containers in content need the same permission. */
.grid2, .grid3, .compare, .steps { min-width: 0; }
.grid2 > *, .grid3 > *, .compare > *, .steps > * { min-width: 0; max-width: 100%; }
pre code { background: none; padding: 0; font-size: inherit; }
:not(pre) > code {
  background: var(--bg-sunk); border: 1px solid var(--line);
  padding: .08em .35em; border-radius: 4px; font-size: .875em;
}

/* syntax highlight */
.tok-kw { color: var(--violet); font-weight: 600; }
.tok-str { color: var(--ok); }
.tok-num { color: var(--aws); }
.tok-com { color: var(--ink-faint); font-style: italic; }
.tok-var { color: var(--oss); }
.tok-iri { color: var(--accent-ink); }
.tok-pfx { color: var(--rose); }

.tablewrap { overflow-x: auto; margin: 1.35rem 0; }
table {
  width: 100%; border-collapse: collapse; font-size: .885rem;
  min-width: 380px;
}
th, td {
  text-align: left; padding: .6rem .75rem;
  border-bottom: 1px solid var(--line); vertical-align: top;
}
th {
  font: 600 .76rem/1.3 var(--sans); letter-spacing: .04em; text-transform: uppercase;
  color: var(--ink-faint); background: var(--bg-sunk);
  border-bottom: 1px solid var(--line-strong);
}
tbody tr:hover { background: var(--bg-sunk); }
td:first-child { font-weight: 500; }

.callout {
  margin: 1.4rem 0; padding: .95rem 1.1rem;
  border-radius: var(--radius-sm); border: 1px solid var(--line);
  border-left: 3px solid var(--c, var(--accent));
  background: var(--cs, var(--accent-soft));
}
.callout .ct {
  font: 650 .875rem/1.4 var(--sans); margin-bottom: .2rem;
  color: var(--c, var(--accent-ink));
  display: flex; align-items: center; gap: .45rem;
}
.callout p { margin: 0; font-size: .92rem; color: var(--ink); }
.callout[data-tone="note"]    { --c: var(--oss);    --cs: var(--oss-soft); }
.callout[data-tone="insight"] { --c: var(--accent-ink); --cs: var(--accent-soft); }
.callout[data-tone="warning"] { --c: var(--rose);   --cs: var(--rose-soft); }
.callout[data-tone="aws"]     { --c: var(--aws);    --cs: var(--aws-soft); }
.callout[data-tone="oss"]     { --c: var(--oss);    --cs: var(--oss-soft); }

.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin: 1.4rem 0; }
.compare > div {
  padding: .95rem 1.05rem; border-radius: var(--radius-sm);
  border: 1px solid var(--line); background: var(--bg-raised);
}
.compare > div:first-child { border-top: 3px solid var(--rose); }
.compare > div:last-child { border-top: 3px solid var(--ok); }
.compare h4 { margin: 0 0 .55rem; font-size: .92rem; }
.compare ul { margin: 0; padding-left: 1.1rem; font-size: .875rem; color: var(--ink-soft); }
.compare li { margin-bottom: .3rem; }

.roadmap { margin: 1.4rem 0; display: grid; gap: .1rem; }
.rm-row {
  display: grid; grid-template-columns: 62px 1fr; gap: .9rem;
  padding: .7rem .8rem; border-radius: var(--radius-sm);
  border-left: 2px solid var(--line-strong);
}
.rm-row:hover { background: var(--bg-sunk); }
.rm-mod { font: 650 .8rem/1.4 var(--mono); color: var(--accent-ink); }
.rm-layer { font: 600 .74rem/1.4 var(--sans); letter-spacing: .05em; text-transform: uppercase; color: var(--ink-faint); }
.rm-what { font-size: .89rem; color: var(--ink-soft); }

.steps { margin: 1.4rem 0; counter-reset: st; display: grid; gap: .55rem; }
.step {
  display: grid; grid-template-columns: 26px 1fr; gap: .8rem;
  padding: .7rem .85rem; background: var(--bg-raised);
  border: 1px solid var(--line); border-radius: var(--radius-sm);
}
.step::before {
  counter-increment: st; content: counter(st);
  width: 26px; height: 26px; border-radius: 50%;
  display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent-ink);
  font: 650 .78rem/1 var(--mono);
}
.step h4 { margin: 0 0 .15rem; font-size: .9rem; }
.step p { margin: 0; font-size: .875rem; color: var(--ink-soft); }

.awsmap { margin: 1.4rem 0; }
.awsmap table { font-size: .855rem; }
.awsmap td:nth-child(2) { color: var(--aws); font-weight: 500; }
.awsmap td:nth-child(3) { color: var(--oss); font-weight: 500; }

/* ---------- widgets ---------- */

.widget {
  margin: 1.5rem 0; padding: 1.1rem;
  background: var(--bg-raised); border: 1px solid var(--line-strong);
  border-radius: var(--radius); box-shadow: var(--shadow);
}
.widget-head {
  display: flex; align-items: center; gap: .5rem; flex-wrap: wrap;
  margin-bottom: .85rem; padding-bottom: .7rem; border-bottom: 1px solid var(--line);
}
.widget-head h4 { margin: 0; font-size: .95rem; }
.widget-head .tag {
  font: 600 .68rem/1 var(--sans); letter-spacing: .07em; text-transform: uppercase;
  color: var(--violet); background: var(--violet-soft);
  padding: .3rem .5rem; border-radius: 100px; margin-left: auto;
}
.widget-hint { font-size: .85rem; color: var(--ink-faint); margin: 0 0 .8rem; }

.pill-row { display: flex; flex-wrap: wrap; gap: .4rem; }
.pill {
  padding: .45rem .75rem; border-radius: 100px; cursor: pointer;
  border: 1px solid var(--line-strong); background: var(--bg-raised);
  font: 500 .84rem/1 var(--sans); color: var(--ink); transition: all .12s;
}
.pill:hover { border-color: var(--ink-faint); }
.pill.on { background: var(--accent); border-color: var(--accent); color: #fff; }
[data-theme="dark"] .pill.on { color: #0d1512; }
.pill.ok { background: var(--ok-soft); border-color: var(--ok); color: var(--ok); }
.pill.bad { background: var(--bad-soft); border-color: var(--bad); color: var(--bad); }

.reveal {
  margin-top: .85rem; padding: .85rem 1rem; border-radius: var(--radius-sm);
  background: var(--bg-sunk); border: 1px solid var(--line);
  font-size: .89rem; line-height: 1.6;
}
.reveal.ok { background: var(--ok-soft); border-color: color-mix(in srgb, var(--ok) 35%, var(--line)); }
.reveal.bad { background: var(--bad-soft); border-color: color-mix(in srgb, var(--bad) 35%, var(--line)); }
.reveal strong { color: var(--ink); }

.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: .9rem; }
.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: .7rem; }

.mini { font-size: .82rem; color: var(--ink-faint); }
.mono { font-family: var(--mono); font-size: .85em; }

textarea.code-in, input.text-in {
  width: 100%; padding: .6rem .7rem;
  border: 1px solid var(--line-strong); border-radius: var(--radius-sm);
  background: var(--bg-sunk); color: var(--ink);
  font: 400 .85rem/1.6 var(--mono); resize: vertical;
}
input.text-in { font-family: var(--sans); font-size: .9rem; }
textarea.code-in:focus, input.text-in:focus { border-color: var(--accent); }

.dropzone {
  min-height: 46px; padding: .5rem; border-radius: var(--radius-sm);
  border: 1.5px dashed var(--line-strong); background: var(--bg-sunk);
  display: flex; flex-wrap: wrap; gap: .35rem; align-content: flex-start;
}
.dropzone.over { border-color: var(--accent); background: var(--accent-soft); }
.dropzone-lbl {
  font: 600 .7rem/1 var(--sans); letter-spacing: .06em; text-transform: uppercase;
  color: var(--ink-faint); margin-bottom: .35rem; display: block;
}

.bindings { font-size: .82rem; }
.bindings th, .bindings td { padding: .4rem .6rem; }
.bindings td { font-family: var(--mono); font-size: .95em; }

/* ---------- quiz ---------- */

.quiz { margin-top: 2rem; }
.qcard {
  padding: 1.1rem 1.2rem; margin-bottom: .9rem;
  background: var(--bg-raised); border: 1px solid var(--line);
  border-radius: var(--radius);
}
.qcard[data-state="ok"]  { border-color: color-mix(in srgb, var(--ok) 45%, var(--line)); }
.qcard[data-state="bad"] { border-color: color-mix(in srgb, var(--bad) 45%, var(--line)); }
.qprompt { font-weight: 550; margin-bottom: .2rem; display: flex; gap: .6rem; }
.qprompt .qn { color: var(--ink-faint); font-family: var(--mono); font-size: .85rem; flex: none; }
.qmulti { font-size: .78rem; color: var(--violet); margin: 0 0 .6rem 1.9rem; }
.choices { display: grid; gap: .4rem; margin-left: 1.9rem; }
.choice {
  display: flex; gap: .6rem; align-items: flex-start;
  padding: .55rem .75rem; border-radius: var(--radius-sm);
  border: 1px solid var(--line); background: var(--bg);
  cursor: pointer; font-size: .9rem; transition: all .12s;
}
.choice:hover { border-color: var(--line-strong); background: var(--bg-sunk); }
.choice input { margin: .25rem 0 0; accent-color: var(--accent); flex: none; }
.choice.picked { border-color: var(--accent); background: var(--accent-soft); }
.choice.right { border-color: var(--ok); background: var(--ok-soft); }
.choice.wrong { border-color: var(--bad); background: var(--bad-soft); }
.choice .mark { margin-left: auto; font-weight: 650; flex: none; }
.qexplain {
  margin: .75rem 0 0 1.9rem; padding: .7rem .9rem;
  border-radius: var(--radius-sm); background: var(--bg-sunk);
  border-left: 2px solid var(--accent); font-size: .875rem; line-height: 1.6;
}

.quizfoot {
  display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
  padding: 1rem 1.2rem; border-radius: var(--radius);
  background: var(--bg-sunk); border: 1px solid var(--line);
}
.score { font: 650 1.35rem/1 var(--sans); letter-spacing: -.02em; }
.score.pass { color: var(--ok); }
.score.fail { color: var(--bad); }

/* ---------- lab block ---------- */

.lab {
  margin: 1.5rem 0; padding: 1.15rem 1.25rem;
  border-radius: var(--radius); border: 1px solid var(--line-strong);
  background: linear-gradient(to bottom right,
    color-mix(in srgb, var(--violet-soft) 70%, var(--bg-raised)), var(--bg-raised));
}
.lab-head { display: flex; align-items: center; gap: .6rem; flex-wrap: wrap; margin-bottom: .5rem; }
.lab-head h3 { margin: 0; font-size: 1.02rem; }
.lab .goal { font-size: .92rem; color: var(--ink-soft); margin: 0 0 .8rem; }
.lab-cmd { margin-bottom: .8rem; }

/* ---------- nav footer ---------- */

.pager {
  display: flex; gap: 1rem; justify-content: space-between;
  padding-block: 2rem; border-top: 1px solid var(--line); margin-top: 2rem;
}
.pager a {
  flex: 1; padding: .9rem 1.1rem; border-radius: var(--radius);
  border: 1px solid var(--line); background: var(--bg-raised);
  text-decoration: none; color: inherit; box-shadow: var(--shadow);
  transition: transform .14s, box-shadow .14s;
}
.pager a:hover { transform: translateY(-2px); box-shadow: var(--shadow-lift); }
.pager .dir { font: 600 .72rem/1 var(--sans); letter-spacing: .07em; text-transform: uppercase; color: var(--ink-faint); }
.pager .t { font-weight: 550; margin-top: .3rem; display: block; }
.pager a:last-child { text-align: right; }

/* ---------- gate / identity ---------- */

.gate {
  position: fixed; inset: 0; z-index: 100;
  display: grid; place-items: center; padding: 20px;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(6px);
}
.gate-card {
  width: 100%; max-width: 420px; padding: 1.6rem;
  background: var(--bg-raised); border: 1px solid var(--line-strong);
  border-radius: var(--radius); box-shadow: var(--shadow-lift);
}
.gate-card h2 { font-size: 1.25rem; }
.gate-card p { font-size: .9rem; color: var(--ink-soft); }
.gate-err { color: var(--bad); font-size: .85rem; margin-top: .5rem; }

/* ---------- progress page ---------- */

.ptable td, .ptable th { font-size: .875rem; }
.ptable .bar { width: 120px; }

.toast {
  position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%) translateY(120%);
  z-index: 200; padding: .7rem 1.1rem; border-radius: 100px;
  background: var(--ink); color: var(--bg);
  font: 550 .875rem/1 var(--sans); box-shadow: var(--shadow-lift);
  transition: transform .3s cubic-bezier(.2,.8,.2,1);
}
.toast.up { transform: translateX(-50%) translateY(0); }

/* ---------- svg diagrams ---------- */

.diagram { margin: 1.5rem 0; }
.diagram svg { width: 100%; height: auto; display: block; }
.dg-box { fill: var(--bg-raised); stroke: var(--line-strong); }
.dg-box-accent { fill: var(--accent-soft); stroke: var(--accent); }
.dg-box-sunk { fill: var(--bg-sunk); stroke: var(--line); }
.dg-t { fill: var(--ink); font: 500 13px var(--sans); }
.dg-t-sm { fill: var(--ink-soft); font: 400 11px var(--sans); }
.dg-t-mono { fill: var(--accent-ink); font: 400 11px var(--mono); }
.dg-line { stroke: var(--line-strong); fill: none; stroke-width: 1.5; }
.dg-line-accent { stroke: var(--accent); fill: none; stroke-width: 1.75; }
.dg-arrow { fill: var(--line-strong); }
.dg-arrow-accent { fill: var(--accent); }

/* ---------- responsive ---------- */

@media (max-width: 1000px) {
  .modlayout { grid-template-columns: minmax(0, 1fr); gap: 1.25rem; }
  .rail { position: static; min-width: 0; max-width: 100%; contain: content; }
  /* The section list becomes a horizontal strip. It needs its own scroll
     container with a definite width, otherwise the long labels inside it
     widen the page instead of scrolling within it. */
  .toc {
    display: flex; gap: .3rem; margin-bottom: .75rem; padding-bottom: .4rem;
    overflow-x: auto; overflow-y: hidden;
    width: 100%; max-width: 100%; min-width: 0;
    scrollbar-width: thin; -webkit-overflow-scrolling: touch;
    overscroll-behavior-x: contain;
  }
  .toc li { flex: 0 0 auto; }
  .toc a { max-width: 52vw; }
  /* The strip is a scroll container, so its own overflow must not count
     towards the document width. contain: content establishes that. */
  .toc { contain: content; }
  /* The label is the part that must truncate. Constraining only the anchor
     lets the span inside it overflow, which is what widens the strip. */
  .toc a > span:last-child {
    display: block; min-width: 0; max-width: 100%;
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
  }
  .toc a { white-space: nowrap; border-left: 0; border-bottom: 2px solid transparent; }
  .toc a.on { border-left: 0; border-bottom-color: var(--accent); }
  .hero-grid { grid-template-columns: 1fr; }
  .hero-art { display: none; }
}

@media (max-width: 720px) {
  body { font-size: 15.5px; }
  /* The header must fit without pushing the page wider. Let the row shrink,
     and drop the least useful link before anything overflows. */
  .topbar-in { gap: .4rem; }
  .topnav { gap: .1rem; min-width: 0; flex-wrap: nowrap; }
  .topnav a { padding: .3rem .4rem; font-size: .8rem; }
  .brand { min-width: 0; }
  .brand span { display: none; }
  .compare, .grid2, .grid3 { grid-template-columns: 1fr; }
  .pager { flex-direction: column; }
  .pager a:last-child { text-align: left; }
  .topnav a { padding: .35rem .5rem; font-size: .82rem; }
  .brand span { display: none; }
  .choices, .qexplain, .qmulti { margin-left: 0; }
  .hero-facts { gap: 1.1rem; }
  .rm-row { grid-template-columns: 1fr; gap: .2rem; }
}

@media (max-width: 420px) {
  /* Progress and Modules are the two that matter on a phone. */
  .topnav a[href="/labs"] { display: none; }
  .topnav { flex-shrink: 1; }
  .wrap { padding-inline: 16px; }
}

@media print {
  .topbar, .rail, .pager, .quiz, .widget { display: none; }
  article.body { max-width: none; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .01ms !important; transition-duration: .01ms !important; }
  html { scroll-behavior: auto; }
}