:root { --bg: #f7f4ee; --panel: #ffffff; --panel-2: #f1ece2; --line: #e3dbcc;
  --text: #1c1a27; --muted: #5b5668; --dim: #9a93a3;
  --amber: #d4441b; --green: #0e7c70; --blue: #3b4cc0; --accent-soft: #fbe3d9; --on-accent: #ffffff;
  --code-bg: #f6f2ea; --kw: #b8361a; --str: #0e7c70; --com: #9a93a3; --num: #7a3db8; --fn: #3b4cc0; }
:root[data-theme="dark"] { --bg: #121119; --panel: #1b1a25; --panel-2: #22202e; --line: #322f42;
  --text: #ece9f2; --muted: #a8a2b6; --dim: #6f6980;
  --amber: #ff7a4d; --green: #3ccbb6; --blue: #9aa5ff; --accent-soft: #3a2119; --on-accent: #1a0f0a;
  --code-bg: #0e0d14; --kw: #ff8f66; --str: #6fdcc9; --com: #6f6980; --num: #d0a3ff; --fn: #9aa5ff; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --bg: #121119; --panel: #1b1a25; --panel-2: #22202e; --line: #322f42;
  --text: #ece9f2; --muted: #a8a2b6; --dim: #6f6980;
  --amber: #ff7a4d; --green: #3ccbb6; --blue: #9aa5ff; --accent-soft: #3a2119; --on-accent: #1a0f0a;
  --code-bg: #0e0d14; --kw: #ff8f66; --str: #6fdcc9; --com: #6f6980; --num: #d0a3ff; --fn: #9aa5ff; } }

* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--bg); color: var(--text); font: 17px/1.6 'Source Sans 3', system-ui, sans-serif; }
a { color: var(--amber); text-underline-offset: 3px; }
h1 { font: 700 clamp(26px, 4vw, 36px)/1.15 'Sora', system-ui, sans-serif; letter-spacing: -.02em; margin: 6px 0 10px; }
.lead { color: var(--muted); margin: 0 0 24px; font-size: 18px; }
.eyebrow { font: 500 12px 'Fira Code', monospace; color: var(--amber); letter-spacing: .1em; text-transform: uppercase; }
.row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.num { font: 500 13px 'Fira Code', monospace; color: var(--amber); min-width: 42px; }
.tag { font: 600 12px 'Source Sans 3', sans-serif; padding: 2px 10px; border-radius: 4px; background: var(--panel-2); color: var(--muted); white-space: nowrap; letter-spacing: .02em; }
.tag.STM32 { color: var(--blue); background: color-mix(in srgb, var(--blue) 13%, transparent); }
.tag.Theory, .tag.Intro { color: var(--amber); background: color-mix(in srgb, var(--amber) 13%, transparent); }
.tag.Arduino, .tag.ESP32 { color: var(--green); background: color-mix(in srgb, var(--green) 14%, transparent); }
.group { margin: 26px 0 10px; font-weight: 700; color: var(--muted); font-size: 13px; text-transform: uppercase; letter-spacing: .08em; }
.step { background: var(--panel); border: 1px solid var(--line); border-left: 4px solid var(--amber); border-radius: 4px 12px 12px 4px; margin: 16px 0; overflow: hidden; }
.step-head { display: flex; align-items: center; gap: 12px; padding: 12px 16px; border-bottom: 1px dashed var(--line); }
.step-n { font: 600 13px 'Fira Code', monospace; color: var(--amber); border: 1.5px solid var(--amber); border-radius: 50%; width: 28px; height: 28px; display: inline-grid; place-items: center; flex: none; }
.step-title { font: 600 16px 'Sora', sans-serif; flex: 1; min-width: 0; }
details.step > summary { cursor: pointer; list-style: none; }
details.step > summary::-webkit-details-marker { display: none; }
details.step:not([open]) > summary { border-bottom: 0; }
details.step > summary .hint { font-size: 12px; color: var(--muted); }
details.step > summary .step-title::before { content: '+ '; color: var(--amber); }
details.step[open] > summary .step-title::before { content: '- '; }
.where { font: 500 13px 'Fira Code', monospace; color: var(--green); padding: 12px 16px 0; overflow-wrap: anywhere; }
.note { color: var(--muted); font-size: 15px; padding: 4px 16px 0; }
.step ul { margin: 10px 0 14px; padding: 0 16px 0 36px; }
.step li { margin: 5px 0; }
.shot { display: block; margin: 8px 0 12px; } .shot img { display: block; width: 100%; height: auto; border: 1px solid var(--line); border-radius: 8px; cursor: zoom-in; }
code { font: 14px 'Fira Code', monospace; background: var(--code-bg); border: 1px solid var(--line); padding: 0 5px; border-radius: 4px; overflow-wrap: anywhere; }
pre { margin: 10px 16px 16px; background: var(--code-bg); border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; overflow-x: auto; font: 14.5px/1.65 'Fira Code', monospace; }
pre .ctx { color: var(--dim); font-style: italic; }
pre .kw { color: var(--kw); } pre .str { color: var(--str); } pre .com { color: var(--com); } pre .n { color: var(--num); } pre .fn { color: var(--fn); }
.copy { background: var(--text); color: var(--bg); border: 0; border-radius: 999px; padding: 6px 16px; font: 600 13px 'Source Sans 3', sans-serif; cursor: pointer; flex: none; }
.copy:hover { background: var(--amber); color: var(--on-accent); }
.copy.done { background: var(--green); color: #fff; }
.video { position: relative; aspect-ratio: 16/9; background: #0c0b10; border-radius: 14px; overflow: hidden; margin: 18px 0 22px; box-shadow: 0 0 0 1px var(--line); }
.video iframe, .video video { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.video .soon { position: absolute; inset: 0; display: grid; place-items: center; color: #b9b3c6; font: 600 15px 'Sora', sans-serif; letter-spacing: .02em;
  background: repeating-linear-gradient(135deg, #15131c 0 14px, #1a1822 14px 28px); }
.box { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 16px 20px; margin: 16px 0; }
.box h3 { margin: 0 0 6px; font: 700 13px 'Sora', sans-serif; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.box ul { margin: 6px 0 0; padding-left: 22px; } .box li { margin: 5px 0; }
.box.next { background: var(--accent-soft); border-color: transparent; } .box.next b { color: var(--amber); }
.box.trouble { border-style: dashed; } .box.trouble li b { color: var(--text); }
h2.sec { font: 700 22px 'Sora', sans-serif; letter-spacing: -.01em; margin: 34px 0 6px; }
.empty { color: var(--muted); background: var(--panel); border: 1px dashed var(--line); border-radius: 12px; padding: 18px; }
@media (max-width: 600px) { pre { font-size: 13px; margin: 10px 10px 14px; padding: 12px; } .step-head { padding: 10px 12px; } .step ul { padding: 0 12px 0 30px; } }
/* calm lesson layout */
.lmeta { margin: 0 0 4px; color: var(--muted); font-size: 14px; display: flex; flex-wrap: wrap; gap: 0 6px; align-items: baseline; } .lmeta .eyebrow { font-size: 12px; } .ptag { color: var(--muted); }
.lesson h1 + .lmeta, article h1 + .lmeta { margin-top: -2px; }
.step { background: none; border: 0; border-top: 1px solid var(--line); border-radius: 0; margin: 0; padding: 16px 0 8px; overflow: visible; }
.step-head { padding: 0; border: 0; gap: 10px; }
.step-n { width: 24px; height: 24px; font-size: 12px; border-width: 1px; }
.step-title { font-size: 16px; }
.step ul { margin: 6px 0 8px; padding: 0 0 0 52px; font-size: 15px; } .step li { margin: 3px 0; }
.where { padding: 6px 0 0 34px; font-size: 12px; }
.why { display: block; margin: 14px 0 6px 37px; padding: 14px 18px 14px 16px; border: 1px solid var(--line); border-left: 3px solid var(--amber); border-radius: 10px; background: var(--panel); font-size: 17px; line-height: 1.6; }
.why .why-h { display: block; font-weight: 700; font-size: 14px; letter-spacing: .04em; text-transform: uppercase; color: var(--amber); margin-bottom: 4px; }
.why .note { padding: 0; font-size: 17px; color: var(--text); }
@media (max-width: 700px) { .step .why { margin-left: 0; } .why, .why .note { font-size: 16px; } }
details.why { display: block; padding: 2px 0 0 34px; font-size: 13px; }
details.why > summary { display: inline; cursor: pointer; color: var(--muted); list-style: none; text-decoration: underline dotted; text-underline-offset: 3px; }
details.why > summary::-webkit-details-marker { display: none; }
details.why[open] > summary { color: var(--amber); }
details.why .note { padding: 4px 0 2px; font-size: 14px; }
.step pre { margin: 8px 0 10px 34px; }
details.more { border-top: 1px solid var(--line); margin-top: 28px; padding-top: 14px; }
details.more > summary { cursor: pointer; color: var(--muted); font-weight: 600; font-size: 15px; }
details.more > summary:hover { color: var(--text); }
details.more h3 { margin: 16px 0 4px; font: 700 12px 'Sora', sans-serif; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
details.more ul { margin: 0; padding-left: 22px; font-size: 15px; } details.more li { margin: 4px 0; } details.more .trouble b { color: var(--text); }
.next-line { margin: 22px 0 0; color: var(--muted); font-size: 15px; }
@media (max-width: 600px) { .step-head { padding: 0; } .step ul { padding: 0 0 0 30px; } .where, details.why { padding-left: 0; } .step pre { margin: 8px 0 10px; } }
/* lesson steps (layout E): one calm column, big numbers, soft thumbnails on the right, lightbox */
.steps { margin-top: 8px; } .step { scroll-margin-top: 120px; }
.step, section.step { background: none; border: 0; border-radius: 0; margin: 0; padding: 40px 0 0; overflow: visible; }
.step .step-head { display: flex; align-items: baseline; gap: 16px; margin: 0 0 10px; padding: 0; border: 0; font: 600 22px/1.25 'Sora', 'IBM Plex Sans', system-ui, sans-serif; letter-spacing: -.01em; }
.step .step-n { font: 700 34px/1 'Sora', 'IBM Plex Sans', system-ui, sans-serif; color: var(--amber); min-width: 40px; width: auto; height: auto; border: 0; border-radius: 0; padding: 0; background: none; display: inline-block; flex: none; }
.step .step-title { font: inherit; flex: 1; min-width: 0; }
.srow.has-thumb { display: grid; grid-template-columns: minmax(0, 1fr) 220px; gap: 0 32px; align-items: start; }
.smain { min-width: 0; }
.step .where { font: 500 13px 'Fira Code', 'JetBrains Mono', monospace; color: var(--green); padding: 0; margin: 0 0 4px 56px; overflow-wrap: anywhere; }
.step p.line { margin: 0 0 4px 56px; }
.step ol.ins { list-style: none; margin: 0 0 0 56px; padding: 0; counter-reset: i; font-size: inherit; }
.step ol.ins > li { counter-increment: i; position: relative; margin: 0; padding: 7px 0 9px; }
.step ol.ins > li::before { content: counter(i, lower-alpha) '.'; position: absolute; left: -22px; top: 7px; color: var(--dim); font: 500 14px 'Fira Code', 'JetBrains Mono', monospace; }
.step ol.ins > li.has-thumb { display: grid; grid-template-columns: minmax(0, 1fr) 220px; gap: 0 32px; align-items: start; }
.step ol.ins > li + li { border-top: 1px dashed color-mix(in srgb, var(--line) 70%, transparent); }
.li-t { min-width: 0; }
.step .code { position: relative; margin: 10px 0 0 56px; }
.step .code pre { margin: 0; padding-right: 76px; }
.step .code .copy { position: absolute; top: 8px; right: 8px; z-index: 1; }

.step details.codefold { margin-left: 56px; } .step details.codefold > summary { cursor: pointer; color: var(--muted); font-size: 14px; }
.step details.codefold .code { margin-left: 0; }
.thumb { position: relative; display: block; width: 100%; padding: 0; margin: 2px 0 0; border: 0; border-radius: 10px; overflow: hidden; background: var(--panel-2); cursor: zoom-in; aspect-ratio: 16 / 9;
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--line) 80%, transparent); transition: box-shadow .2s, transform .2s; }
.thumb img { display: block; width: 100%; height: 100%; object-fit: cover; object-position: left top; filter: blur(1.2px) saturate(1.1); opacity: .82; transform: scale(1.03); transition: filter .25s, opacity .25s, transform .25s; }
.thumb::after { content: ''; position: absolute; inset: 0; pointer-events: none; background: linear-gradient(160deg, color-mix(in srgb, var(--bg) 6%, transparent) 30%, color-mix(in srgb, var(--bg) 42%, transparent)); transition: opacity .25s; }
.thumb .mag { position: absolute; right: 7px; bottom: 7px; z-index: 1; width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center; background: color-mix(in srgb, var(--panel) 88%, transparent); color: var(--text); opacity: 0; transition: opacity .2s; box-shadow: 0 1px 4px rgba(0,0,0,.18); }
.thumb .mag svg { width: 14px; height: 14px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; }
.thumb:hover, .thumb:focus-visible { box-shadow: 0 0 0 1px var(--amber), 0 4px 14px rgba(0,0,0,.12); }
.thumb:hover img, .thumb:focus-visible img { filter: blur(.3px) saturate(1.05); opacity: 1; transform: scale(1.0); }
.thumb:hover::after, .thumb:focus-visible::after { opacity: .35; }
.thumb:hover .mag, .thumb:focus-visible .mag { opacity: 1; }
.thumb:focus-visible { outline: 2px solid var(--amber); outline-offset: 2px; }
.thumb.fig { aspect-ratio: auto; width: calc(100% - 56px); max-width: 640px; margin: 12px 0 6px 56px; background: none; border-radius: 12px; }
.thumb.fig img { height: auto; object-fit: contain; filter: none; opacity: 1; transform: none; }
.thumb.fig::after { display: none; }
@media (max-width: 700px) { .thumb.fig { margin-left: 0; width: 100%; max-width: 100%; } }
details.toc { margin: 4px 0 6px; font-size: 15px; }
details.toc > summary { cursor: pointer; color: var(--muted); font-weight: 600; width: max-content; max-width: 100%; }
details.toc > summary:hover { color: var(--text); }
details.toc ol { margin: 8px 0 0; padding-left: 26px; columns: 2 260px; column-gap: 28px; } details.toc li { margin: 2px 0; break-inside: avoid; }
details.toc a { color: var(--text); text-decoration: none; } details.toc a:hover { color: var(--amber); }
html.lb-lock { overflow: hidden; }
#la-lb { position: fixed; inset: 0; z-index: 2147483000; display: none; align-items: center; justify-content: center; padding: 56px 72px 64px; background: rgba(10, 9, 14, .92); }
#la-lb.on { display: flex; }
#la-lb figure { margin: 0; max-width: 100%; max-height: 100%; display: flex; flex-direction: column; align-items: center; gap: 10px; min-height: 0; }
#la-lb img { display: block; max-width: 100%; max-height: calc(100vh - 140px); width: auto; height: auto; border-radius: 8px; box-shadow: 0 10px 40px rgba(0,0,0,.5); filter: none; opacity: 1; }
#la-lb figcaption { color: #e6e3ec; font: 15px/1.45 'Source Sans 3', 'IBM Plex Sans', system-ui, sans-serif; text-align: center; max-width: 900px; }
#la-lb figcaption code { background: rgba(255,255,255,.1); border: 0; color: #fff; }
#la-lb figcaption a { color: #ffb38f; }
#la-lb .lb-n { color: #9b96a6; font: 500 12px 'Fira Code', monospace; margin-right: 10px; }
#la-lb button { position: absolute; width: 44px; height: 44px; border-radius: 50%; border: 0; background: rgba(255,255,255,.12); color: #fff; font: 26px/1 system-ui, sans-serif; cursor: pointer; display: grid; place-items: center; padding: 0 0 3px; }
#la-lb button:hover { background: rgba(255,255,255,.24); } #la-lb button:focus-visible { outline: 2px solid #ffb38f; outline-offset: 2px; }
#la-lb .lb-x { top: 12px; right: 12px; } #la-lb .lb-p { left: 14px; top: 50%; transform: translateY(-50%); } #la-lb .lb-nx { right: 14px; top: 50%; transform: translateY(-50%); }
#la-lb.one .lb-p, #la-lb.one .lb-nx { display: none; }
@media (max-width: 699px) {
  .step, section.step { padding-top: 32px; }
  .step .step-head { font-size: 19px; gap: 10px; } .step .step-n { font-size: 28px; min-width: 30px; }
  .srow.has-thumb, .step ol.ins > li.has-thumb { display: block; }
  .srow > .thumb, .step ol.ins > li > .thumb { width: 50%; margin-top: 8px; }
  .srow > .thumb { margin-left: 40px; }
  .step .where, .step p.line, .step .code, .step details.why, .step details.codefold { margin-left: 0; }
  .srow > .thumb { margin-left: 0; }
  .step ol.ins { margin-left: 22px; }
  .thumb .mag { opacity: 1; }
  details.toc ol { columns: 1; }
  #la-lb { padding: 56px 8px 96px; } #la-lb .lb-p, #la-lb .lb-nx { top: auto; bottom: 22px; transform: none; } #la-lb .lb-p { left: calc(50% - 56px); } #la-lb .lb-nx { right: calc(50% - 56px); }
  #la-lb img { max-height: calc(100vh - 200px); }
}

.doc.lesson-doc { max-width: 1120px; }
img, svg { max-width: 100%; }
.skip { position: absolute; left: -999px; } .skip:focus { left: 12px; top: 12px; z-index: 20; background: var(--panel); padding: 8px 12px; }
.top { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.top-in { max-width: 1200px; margin: 0 auto; display: flex; align-items: center; gap: 18px; padding: 12px 24px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font: 700 16px 'Sora', sans-serif; letter-spacing: -.01em; white-space: nowrap; }
.brand svg { width: 28px; height: 28px; flex: none; }
.brand span { color: var(--amber); font-weight: 600; }
.nav { display: flex; gap: 18px; flex: 1; justify-content: flex-end; align-items: center; }
.nav a { color: var(--muted); text-decoration: none; font-weight: 600; font-size: 15px; }
.nav a:hover, .nav a[aria-current] { color: var(--text); }
.icon-btn { background: none; border: 1px solid var(--line); color: var(--text); border-radius: 999px; width: 36px; height: 36px; display: grid; place-items: center; cursor: pointer; flex: none; }
.icon-btn svg { width: 18px; height: 18px; }
.icon-btn .moon { display: none; }
:root[data-theme="dark"] .icon-btn .sun { display: none; } :root[data-theme="dark"] .icon-btn .moon { display: block; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .icon-btn .sun { display: none; } :root:not([data-theme="light"]) .icon-btn .moon { display: block; } }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 20px; border-radius: 999px; font: 600 16px 'Sora', sans-serif; text-decoration: none; border: 2px solid transparent; white-space: nowrap; }
.btn.primary { background: var(--amber); color: var(--on-accent); }
.btn.primary:hover { filter: brightness(1.07); }
.btn.ghost { border-color: var(--text); color: var(--text); }
.btn.ghost:hover { background: var(--text); color: var(--bg); }
.btn.sm { padding: 7px 14px; font-size: 14px; }
.badge { font: 600 11px 'Fira Code', monospace; letter-spacing: .06em; text-transform: uppercase; padding: 2px 8px; border-radius: 4px; white-space: nowrap; }
.badge.free { background: color-mix(in srgb, var(--green) 16%, transparent); color: var(--green); }
.badge.mem { background: color-mix(in srgb, var(--amber) 14%, transparent); color: var(--amber); }
.badge.soon { background: var(--panel-2); color: var(--muted); }

/* docs layout */
.doc { max-width: 1200px; margin: 0 auto; padding: 28px 24px 80px; }
.doc > article { max-width: none; min-width: 0; }
.doc > article > * { max-width: 1100px; box-sizing: border-box; }
.doc > article * { box-sizing: border-box; }
.fusion-fig { max-width: 520px; margin: 24px 0 0; }
.hw-photo { display: block; width: 100%; height: auto; border-radius: 10px; margin-bottom: 10px; }
.hero-photo, .fusion-photo { display: block; width: 100%; height: auto; border-radius: 14px; }
.crumbrow { max-width: 1200px; margin: 0 auto; padding: 0 24px 10px; }
.crumbnav { display: flex; align-items: center; gap: 6px; min-width: 0; position: relative; }
.crumbnav .sep { color: var(--dim); }
.menu { position: relative; min-width: 0; }
.menu summary { list-style: none; cursor: pointer; display: flex; align-items: center; gap: 6px; font: 600 13.5px 'Sora', sans-serif; color: var(--text); background: var(--panel); border: 1px solid var(--line); border-radius: 999px; padding: 5px 12px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 100%; }
.menu summary::-webkit-details-marker { display: none; }
.menu summary::after { content: ""; flex: none; width: 7px; height: 7px; border-right: 1.5px solid var(--muted); border-bottom: 1.5px solid var(--muted); transform: rotate(45deg) translateY(-2px); margin-left: 2px; }
.menu summary .hide-sm { overflow: hidden; text-overflow: ellipsis; }
.menu summary:hover { border-color: var(--muted); } .menu[open] summary { border-color: var(--amber); }
.menu summary:focus-visible { outline: 2px solid var(--amber); outline-offset: 2px; }
.menu-list { position: absolute; top: calc(100% + 6px); left: 0; z-index: 30; width: min(420px, calc(100vw - 32px)); max-height: min(70vh, 600px); overflow: auto; background: var(--panel); border: 1px solid var(--line); border-radius: 14px; box-shadow: 0 14px 36px rgba(15, 12, 25, .18); padding: 8px 8px 10px; font-size: 15px; }
.menu-sub { font: 700 11px 'Sora', sans-serif; letter-spacing: .09em; text-transform: uppercase; color: var(--muted); padding: 8px 10px 6px; }
.ch + .ch { border-top: 1px solid var(--line); margin-top: 4px; padding-top: 4px; }
.ch-head { display: flex; align-items: baseline; gap: 10px; padding: 6px 10px; border-radius: 9px; color: var(--text); text-decoration: none; font: 600 14px/1.35 'Sora', sans-serif; }
.ch-head:hover { background: var(--panel-2); }
.ch-num { font: 500 12px 'Fira Code', monospace; color: var(--amber); min-width: 18px; }
.ch.on .ch-head, .ch-head[aria-current] { color: var(--amber); }
.ch-lessons { padding-left: 18px; }
.ls { display: flex; align-items: baseline; gap: 10px; padding: 6px 10px; border-radius: 9px; color: var(--muted); text-decoration: none; line-height: 1.35; }
a.ls:hover { background: var(--panel-2); color: var(--text); }
.ls-num { flex: none; min-width: 30px; font: 500 12px 'Fira Code', monospace; }
.ls-title { flex: 1; }
.ls svg { flex: none; align-self: center; }
.ls.on { background: var(--accent-soft); color: var(--amber); font-weight: 600; }
.ls.soon { opacity: .6; } .ls-soon { font-size: 12px; }
.lock { width: 12px; height: 12px; flex: none; margin-top: 4px; opacity: .7; }
.crumbs { font-size: 14px; color: var(--muted); margin-bottom: 6px; }
.crumbs a { color: var(--muted); text-decoration: none; } .crumbs a:hover { color: var(--amber); }
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 40px; position: sticky; bottom: 0; z-index: 20; padding: 10px 0 12px; background: linear-gradient(to bottom, transparent, var(--bg) 22%); }
.pager a { min-width: 0; box-shadow: 0 4px 18px rgba(0,0,0,.08); }
.pager a span, .pager a { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.pager a { display: block; padding: 14px 18px; border: 1px solid var(--line); border-radius: 12px; text-decoration: none; color: var(--text); background: var(--panel); }
.pager a:hover { border-color: var(--amber); }
.pager small { display: block; color: var(--muted); font: 600 12px 'Fira Code', monospace; text-transform: uppercase; letter-spacing: .08em; margin-bottom: 4px; }
.pager .nx { text-align: right; grid-column: 2; }
.lessons { display: grid; gap: 12px; margin-top: 18px; }
.lcard { display: grid; grid-template-columns: 52px minmax(0, 1fr); gap: 4px 14px; text-decoration: none; color: inherit; background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; }
a.lcard:hover { border-color: var(--amber); }
.lcard .num { font-size: 15px; padding-top: 3px; }
.lcard h2 { font: 600 17px/1.3 'Sora', sans-serif; margin: 0; }
.lcard p { grid-column: 2; margin: 0; color: var(--muted); font-size: 15px; }
.lcard .row { gap: 8px; }
.lcard.later { opacity: .6; }
.members { background: var(--panel); border: 2px solid var(--amber); border-radius: 16px; padding: 22px 24px; margin: 26px 0; }
.members h3 { font: 700 20px 'Sora', sans-serif; margin: 0 0 6px; color: var(--text); text-transform: none; letter-spacing: -.01em; }
.members p { margin: 0 0 16px; color: var(--muted); }
.members .ctas { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.members .ctas a.plain { color: var(--muted); font-size: 15px; }

/* home: one calm column, like the lesson pages */
.wrap { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.home { max-width: 880px; }
.hero { padding: 72px 0 8px; }
.hero h1 { font-size: clamp(36px, 5.6vw, 58px); line-height: 1.05; letter-spacing: -.035em; margin: 14px 0 18px; }
.hero h1 em { font-style: normal; color: var(--amber); }
.hero .lead { font-size: 20px; max-width: 34em; }
.ctas { display: flex; gap: 12px; flex-wrap: wrap; }
.fine { color: var(--muted); font-size: 15px; margin-top: 16px; }
.hero-art { margin-top: 40px; background: var(--panel); border: 1px solid var(--line); border-radius: 16px; padding: 14px; }
.sect { padding: 88px 0 0; }
.sect > .eyebrow { display: block; margin-bottom: 8px; }
.sect h2.big { font: 700 clamp(26px, 3.4vw, 36px)/1.15 'Sora', sans-serif; letter-spacing: -.025em; margin: 0 0 24px; }
.outline { display: grid; gap: 12px; }
.och { background: var(--panel); border: 1px solid var(--line); border-radius: 16px; overflow: hidden; }
.och > summary, .och .sum { list-style: none; display: grid; grid-template-columns: 64px minmax(0, 1fr); gap: 16px; align-items: start; padding: 20px 22px; }
.och > summary { cursor: pointer; } .och > summary::-webkit-details-marker { display: none; }
.och .chn { font: 700 40px/1 'Sora', sans-serif; color: var(--amber); letter-spacing: -.04em; }
.och h3 { font: 600 19px/1.3 'Sora', sans-serif; margin: 2px 0 4px; } .och h3 .badge { vertical-align: 2px; margin-left: 4px; }
.och .sum p, .och summary p { margin: 0; color: var(--muted); font-size: 16px; }
.och ol { list-style: none; margin: 0; padding: 0 22px 16px 102px; }
.och li { display: flex; gap: 10px; align-items: baseline; padding: 7px 0; border-top: 1px dashed var(--line); }
.och li b { font: 500 13px 'Fira Code', monospace; color: var(--muted); min-width: 38px; }
.och li a { color: var(--text); text-decoration: none; flex: 1; } .och li a:hover { color: var(--amber); }
.och li span.t { flex: 1; color: var(--muted); }
.och.coming { background: transparent; } .och.coming .chn { color: var(--muted); }
.anatomy { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.anatomy li, .fit > div, .plan { background: var(--panel); border: 1px solid var(--line); border-radius: 16px; padding: 20px 22px; }
.anatomy h3, .fit h3, .plan h3 { font: 600 18px 'Sora', sans-serif; margin: 0 0 6px; }
.anatomy p, .fit p { margin: 0; color: var(--muted); }
.need { list-style: none; padding: 0; margin: 0; background: var(--panel); border: 1px solid var(--line); border-radius: 16px; }
.need li { display: grid; grid-template-columns: 110px minmax(0, 1fr); gap: 16px; padding: 16px 22px; border-top: 1px solid var(--line); }
.need li:first-child { border-top: 0; }
.need .hw-photo { grid-column: 1 / -1; width: 100%; height: auto; border-radius: 12px; }
.need .k { font: 500 12px/1.9 'Fira Code', monospace; color: var(--green); text-transform: uppercase; letter-spacing: .08em; }
.need h3 { font: 600 17px/1.35 'Sora', sans-serif; margin: 0 0 2px; } .need p { margin: 0; color: var(--muted); font-size: 15px; }
.fit { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.plans { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; align-items: start; }
.plan.main { border: 2px solid var(--amber); }
.plan .price { font-family: 'Sora', sans-serif; font-weight: 700; font-size: 32px; letter-spacing: -.02em; margin: 0 0 12px; }
.plan .price small { display: block; font-family: inherit; font-weight: 400; font-size: 15px; color: var(--muted); letter-spacing: 0; }
.plan ul { margin: 0 0 18px; padding-left: 20px; color: var(--muted); } .plan li { margin: 4px 0; }
.plan .guar { margin: 12px 0 0; font-size: 15px; color: var(--muted); }
.band { margin: 88px 0 0; background: var(--panel); border: 1px solid var(--line); border-radius: 16px; padding: 36px; text-align: center; }
.band h2 { font: 700 clamp(22px, 3vw, 30px)/1.2 'Sora', sans-serif; margin: 0 0 6px; letter-spacing: -.02em; }
.band p { margin: 0 0 20px; color: var(--muted); } .band .ctas { justify-content: center; }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; list-style: none; padding: 18px 0; font: 600 18px 'Sora', sans-serif; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; color: var(--amber); font-size: 22px; line-height: 1; } .faq details[open] summary::after { content: '-'; }
.faq p { margin: 0 0 18px; color: var(--muted); max-width: 46em; }
footer.foot { border-top: 1px solid var(--line); margin-top: 90px; }
.foot-in { max-width: 1200px; margin: 0 auto; padding: 36px 24px 48px; display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 28px; color: var(--muted); font-size: 15px; }
.foot-in h4 { font: 700 13px 'Sora', sans-serif; text-transform: uppercase; letter-spacing: .08em; color: var(--text); margin: 0 0 10px; }
.foot-in a { color: var(--muted); text-decoration: none; display: block; padding: 3px 0; } .foot-in a:hover { color: var(--amber); }
.foot-in p { margin: 10px 0 0; }

/* svg figure styling (themes with tokens) */
.svg-bg { fill: var(--panel-2); } .svg-line { stroke: var(--line); } .svg-text { fill: var(--muted); font: 500 12px 'Fira Code', monospace; }
.svg-ink { fill: var(--text); } .svg-ink-s { stroke: var(--text); } .svg-acc { fill: var(--amber); } .svg-acc-s { stroke: var(--amber); }
.svg-teal-s { stroke: var(--green); } .svg-teal { fill: var(--green); } .svg-ind-s { stroke: var(--blue); } .svg-ind { fill: var(--blue); }
.svg-pcb { fill: #1f3a5f; } .svg-pcb2 { fill: #13243d; } .svg-esp { fill: #0d5c55; } .svg-chip { fill: #232029; } .svg-pad { fill: #d6b25e; } .svg-white { fill: #f4f1ea; }

@media (max-width: 1000px) {
  .doc { padding-top: 16px; }
  .gallery, .hw { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}
@media (max-width: 720px) {
  .top-in { padding: 10px 16px; gap: 10px; }
  .nav .hide-sm, .menu .hide-sm { display: none; }
  .crumbrow { padding: 0 16px 8px; } .menu { position: static; }
  .brand .wordmark-sub { display: none; }
  .doc { padding-left: 16px; padding-right: 16px; }
  .wrap { padding: 0 16px; }
  .gallery, .hw, .anatomy, .fit, .plans { grid-template-columns: minmax(0, 1fr); }
  .hero { padding-top: 40px; } .hero .lead { font-size: 18px; } .hero-art { margin-top: 28px; padding: 10px; }
  .sect { padding-top: 64px; } .sect h2.big { margin-bottom: 18px; }
  .och > summary, .och .sum { grid-template-columns: 40px minmax(0, 1fr); gap: 12px; padding: 16px; }
  .och .chn { font-size: 30px; } .och ol { padding: 0 16px 14px 16px; }
  .need li { grid-template-columns: minmax(0, 1fr); gap: 2px; padding: 14px 16px; }
  .anatomy li, .fit > div, .plan { padding: 16px; }
  .band { padding: 28px 18px; }
  .foot-in { grid-template-columns: minmax(0, 1fr); padding: 28px 16px 40px; }
  .pager { grid-template-columns: 1fr 1fr; gap: 8px; } .pager a { padding: 8px 12px; font-size: 14px; } .pager .nx { grid-column: 2; }
  .btn { padding: 11px 16px; font-size: 15px; }
  .members { padding: 18px; }
}
@media (max-width: 520px) { .nav a:not(.btn) { display: none; } .top .brand { white-space: normal; font-size: 14px; line-height: 1.1; min-width: 0; } .nav { min-width: 0; } }
@media (max-width: 340px) { .nav .btn.sm { display: none; } }