/* ------------------------------------------------------------------ tokens */
:root {
  --bg: #FAF9F6;
  --bg-alt: #F2F0EA;
  --card: #FFFFFF;
  --ink: #0F1B33;
  --ink-2: #33405A;
  --muted: #5E6878;
  --faint: #8C95A4;
  --line: #E6E2D9;
  --line-2: #EFECE5;
  --chip: #F3F1EC;
  --accent: #0F766E;
  --accent-ink: #0B5C56;
  --accent-soft: #DDEFEC;
  --glow: rgba(15, 118, 110, .16);
  --warm: #9A5B2F;
  --warm-soft: #F5E9DE;
  --term-bg: #0C1422;
  --term-ink: #E6EDF3;
  --term-dim: #8FA3BF;
  --term-ok: #7DD3C7;
  --shadow: 0 1px 2px rgba(15, 27, 51, .04), 0 10px 30px rgba(15, 27, 51, .06);
  --shadow-lg: 0 2px 4px rgba(15, 27, 51, .04), 0 24px 60px rgba(15, 27, 51, .10);
  --radius: 18px;
  --display: "Instrument Serif", "Iowan Old Style", Georgia, serif;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --maxw: 1180px;
  --ease: cubic-bezier(.2, .7, .2, 1);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0B111C; --bg-alt: #0F1726; --card: #111A29; --ink: #EAEEF5; --ink-2: #C9D1DE; --muted: #9AA5B7;
    --faint: #6B778C; --line: #1F2A3D; --line-2: #182233; --chip: #172133; --accent: #4CC9B7; --accent-ink: #86DDD0;
    --accent-soft: rgba(76, 201, 183, .13); --glow: rgba(76, 201, 183, .16); --warm: #E3A778; --warm-soft: rgba(227, 167, 120, .13);
    --term-bg: #070C16; --shadow: 0 1px 2px rgba(0,0,0,.3), 0 10px 30px rgba(0,0,0,.25);
    --shadow-lg: 0 2px 4px rgba(0,0,0,.3), 0 24px 60px rgba(0,0,0,.35);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0B111C; --bg-alt: #0F1726; --card: #111A29; --ink: #EAEEF5; --ink-2: #C9D1DE; --muted: #9AA5B7;
  --faint: #6B778C; --line: #1F2A3D; --line-2: #182233; --chip: #172133; --accent: #4CC9B7; --accent-ink: #86DDD0;
  --accent-soft: rgba(76, 201, 183, .13); --glow: rgba(76, 201, 183, .16); --warm: #E3A778; --warm-soft: rgba(227, 167, 120, .13);
  --term-bg: #070C16; --shadow: 0 1px 2px rgba(0,0,0,.3), 0 10px 30px rgba(0,0,0,.25);
  --shadow-lg: 0 2px 4px rgba(0,0,0,.3), 0 24px 60px rgba(0,0,0,.35);
  color-scheme: dark;
}

/* ------------------------------------------------------------------ base */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 80px; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 400 16px/1.7 var(--sans); -webkit-font-smoothing: antialiased; }
a { color: inherit; }
img { max-width: 100%; display: block; }
h1, h2 { font-family: var(--display); font-weight: 400; line-height: 1.05; margin: 0; letter-spacing: -.012em; }
h3 { font-family: var(--sans); font-weight: 600; line-height: 1.3; margin: 0; letter-spacing: -.01em; }
h1 em, h2 em { font-style: italic; color: var(--accent); }
p { margin: 0; }
code, .mono { font-family: var(--mono); font-size: .9em; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 6px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: var(--bg); padding: 8px 14px; border-radius: 8px; z-index: 100; }
.skip:focus { left: 16px; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
@media (max-width: 640px) { .wrap { padding: 0 16px; } }

/* ------------------------------------------------------------------ nav */
.progress { position: fixed; top: 0; left: 0; height: 2px; width: 100%; background: var(--accent); transform-origin: 0 50%; transform: scaleX(0); z-index: 60; }
.nav { position: sticky; top: 0; z-index: 50; background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(1.4) blur(12px); -webkit-backdrop-filter: saturate(1.4) blur(12px); border-bottom: 1px solid transparent; transition: border-color .3s; }
.nav.scrolled { border-bottom-color: var(--line); }
.nav .wrap { display: flex; align-items: center; gap: 24px; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; font: 600 16px var(--sans); text-decoration: none; white-space: nowrap; letter-spacing: -.01em; }
.brand i { width: 30px; height: 30px; border-radius: 9px; background: var(--ink); color: var(--bg); display: grid; place-items: center; font: 400 17px var(--display); font-style: normal; }
.nav-links { display: flex; align-items: center; gap: 28px; margin: 0 0 0 auto; list-style: none; padding: 0; }
.nav-links a { text-decoration: none; color: var(--muted); font-size: 14.5px; font-weight: 500; transition: color .2s; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--ink); }
.nav-links .pill { color: var(--bg); background: var(--ink); padding: 8px 18px; border-radius: 999px; }
.nav-links .pill:hover { color: var(--bg); opacity: .88; }
.theme-btn { background: none; border: 1px solid var(--line); color: var(--muted); width: 36px; height: 36px; border-radius: 10px; cursor: pointer; display: grid; place-items: center; flex: none; }
.theme-btn:hover { color: var(--ink); border-color: var(--faint); }
.theme-btn svg { width: 17px; height: 17px; }
@media (max-width: 860px) { .nav-links li.hide-sm { display: none; } .nav-links { gap: 18px; } .nav .wrap { gap: 12px; } }
@media (max-width: 520px) { .nav-links li:has(.pill) { display: none; } .brand span { display: none; } }

/* ------------------------------------------------------------------ shared bits */
.eyebrow { display: inline-flex; align-items: center; gap: 10px; font: 600 12px/1 var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--accent); }
.eyebrow::before { content: ""; width: 22px; height: 1px; background: currentColor; }
.section { padding: 120px 0 0; }
.section-head { display: flex; align-items: end; justify-content: space-between; gap: 24px 48px; flex-wrap: wrap; margin-bottom: 44px; }
.section-head h2 { font-size: clamp(36px, 4.6vw, 56px); margin-top: 16px; max-width: 760px; }
.section-head p { color: var(--muted); max-width: 440px; font-size: 16.5px; }
.link-arrow { font-weight: 600; font-size: 15px; text-decoration: none; white-space: nowrap; color: var(--ink); }
.link-arrow:hover { color: var(--accent); }
.btn { display: inline-flex; align-items: center; gap: 10px; height: 50px; padding: 0 24px; border-radius: 999px; font-weight: 500; font-size: 15px;
  text-decoration: none; border: 1px solid var(--line); background: var(--card); color: var(--ink); transition: transform .2s var(--ease), box-shadow .2s, background .2s; cursor: pointer; }
.btn:hover { transform: translateY(-1px); box-shadow: var(--shadow); }
.btn-primary { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.btn .arr { transition: transform .2s var(--ease); }
.btn:hover .arr { transform: translateX(3px); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }
.chip { display: inline-block; background: var(--chip); color: var(--ink-2); font-size: 13px; padding: 4px 12px; border-radius: 999px; }
.tag { display: inline-block; font-size: 12px; font-weight: 500; padding: 3px 10px; border-radius: 999px; background: var(--accent-soft); color: var(--accent-ink); white-space: nowrap; }
.tag.soon { background: var(--warm-soft); color: var(--warm); }
.tag.plain { background: var(--chip); color: var(--muted); }

/* ------------------------------------------------------------------ motion */
@keyframes rise { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }
@keyframes blink { 50% { opacity: 0; } }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 var(--glow); } 70% { box-shadow: 0 0 0 10px transparent; } 100% { box-shadow: 0 0 0 0 transparent; } }
@keyframes float { 50% { transform: translateY(-6px); } }
.js .rise { opacity: 0; animation: rise .9s var(--ease) forwards; animation-delay: var(--d, 0s); }
.js .reveal { opacity: 0; transform: translateY(28px); transition: opacity .9s var(--ease), transform .9s var(--ease); transition-delay: var(--d, 0s); }
.js .reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .rise, .js .reveal { opacity: 1; transform: none; animation: none; transition: none; }
  .journey .rail i, .journey .stop { transition: none !important; }
}

/* ------------------------------------------------------------------ hero */
.hero { position: relative; padding: 72px 0 40px; overflow: hidden; }
.hero::before { content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image: radial-gradient(var(--line) 1px, transparent 1px); background-size: 26px 26px;
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 70% 40%, #000 20%, transparent 75%); mask-image: radial-gradient(ellipse 70% 60% at 70% 40%, #000 20%, transparent 75%); }
.hero::after { content: ""; position: absolute; width: 620px; height: 620px; right: -120px; top: -160px; border-radius: 50%; pointer-events: none;
  background: radial-gradient(circle, var(--glow), transparent 65%); }
.hero .wrap { position: relative; z-index: 1; display: grid; grid-template-columns: 1.2fr 1fr; gap: 64px; align-items: center; }
.status { display: inline-flex; align-items: center; gap: 10px; font-size: 13.5px; color: var(--ink-2); background: var(--card); border: 1px solid var(--line); padding: 7px 14px 7px 10px; border-radius: 999px; }
.status b { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); animation: pulse 2.4s infinite; }
.hero h1 { font-size: clamp(46px, 6.4vw, 86px); line-height: 1; margin: 28px 0 26px; }
.hero .lead { font-size: 18.5px; color: var(--muted); max-width: 580px; line-height: 1.65; }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 36px; }
.hero-chips { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 30px; }
.hero-chips span { font-size: 13px; color: var(--muted); border: 1px solid var(--line); padding: 5px 12px; border-radius: 999px; background: color-mix(in srgb, var(--card) 70%, transparent); }

.profile { padding: 26px; box-shadow: var(--shadow-lg); animation: float 7s ease-in-out infinite; animation-delay: 1.4s; }
.js .profile.rise { animation: rise .9s var(--ease) forwards, float 7s ease-in-out 1.6s infinite; }
.profile .who { display: flex; gap: 14px; align-items: center; }
.avatar { width: 54px; height: 54px; border-radius: 16px; flex: none; overflow: hidden; display: grid; place-items: center;
  background: linear-gradient(140deg, #14305A, #0F766E); color: #fff; font: 400 24px var(--display); }
.avatar img { width: 100%; height: 100%; object-fit: cover; }
.profile .who b { display: block; font-weight: 600; font-size: 16.5px; }
.profile .who span { color: var(--muted); font-size: 13.5px; line-height: 1.45; display: block; }
.term { background: var(--term-bg); border-radius: 12px; padding: 14px 16px 16px; font: 12.5px/1.85 var(--mono); color: var(--term-dim); overflow: hidden; }
.term .bar { display: flex; align-items: center; gap: 7px; margin-bottom: 10px; }
.term .bar i { width: 10px; height: 10px; border-radius: 50%; background: #FF5F57; }
.term .bar i:nth-child(2) { background: #FEBC2E; } .term .bar i:nth-child(3) { background: #28C840; }
.term .bar small { margin-left: auto; font-size: 11px; color: #56657D; }
.term div { white-space: pre; overflow: hidden; text-overflow: ellipsis; }
.term .cmd { color: var(--term-ink); } .term .ok { color: var(--term-ok); }
.term .cur { display: inline-block; width: 7px; height: 14px; background: var(--term-ok); vertical-align: -2px; margin-left: 2px; animation: blink 1s steps(1) infinite; }
.profile .term { margin: 20px 0; min-height: 200px; }
.nums { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.nums div { background: var(--bg-alt); border-radius: 12px; padding: 12px 12px 10px; }
.nums b { display: block; font: 400 28px/1 var(--display); }
.nums span { font-size: 11.5px; color: var(--muted); line-height: 1.3; display: block; margin-top: 6px; }
.scroll-cue { position: relative; z-index: 1; display: flex; align-items: center; gap: 12px; justify-content: center; margin-top: 64px; color: var(--faint); font-size: 13px; text-decoration: none; }
.scroll-cue i { width: 22px; height: 34px; border: 1.5px solid var(--faint); border-radius: 12px; position: relative; }
.scroll-cue i::after { content: ""; position: absolute; left: 50%; top: 7px; width: 3px; height: 7px; margin-left: -1.5px; border-radius: 2px; background: var(--faint); animation: rise 1.6s infinite reverse; }
@media (max-width: 960px) {
  .hero { padding: 40px 0 24px; }
  .hero .wrap { grid-template-columns: 1fr; gap: 44px; }
  .profile { animation: none; }
  .js .profile.rise { animation: rise .9s var(--ease) forwards; }
}
@media (max-width: 480px) { .nums { grid-template-columns: repeat(2, 1fr); } .term { font-size: 11.5px; } }

/* ------------------------------------------------------------------ journey */
.journey { position: relative; margin-top: 12px; }
.journey ol { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(6, 1fr); gap: 18px; position: relative; }
.journey .rail { position: absolute; left: 0; right: 0; top: 11px; height: 2px; background: var(--line); border-radius: 2px; }
.journey .rail i { position: absolute; inset: 0; background: linear-gradient(90deg, var(--faint), var(--accent)); transform-origin: 0 50%; transform: scaleX(0); transition: transform 1.8s var(--ease); border-radius: 2px; }
.journey.in .rail i { transform: scaleX(1); }
.stop { position: relative; padding-top: 40px; opacity: 1; }
.js .journey .stop { opacity: 0; transform: translateY(12px); transition: opacity .7s var(--ease), transform .7s var(--ease); transition-delay: calc(var(--i) * .22s + .2s); }
.js .journey.in .stop { opacity: 1; transform: none; }
.stop::before { content: ""; position: absolute; top: 4px; left: 0; width: 16px; height: 16px; border-radius: 50%; background: var(--bg); border: 2px solid var(--faint); }
.stop.now::before { background: var(--accent); border-color: var(--accent); animation: pulse 2.4s infinite; }
.stop .yr { font: 400 34px/1 var(--display); }
.stop .era { display: block; font: 600 11px var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--accent); margin: 10px 0 12px; }
.stop b { display: block; font-weight: 600; font-size: 15px; }
.stop .rl { display: block; color: var(--ink-2); font-size: 13.5px; margin-bottom: 8px; }
.stop p { color: var(--muted); font-size: 13.5px; line-height: 1.55; }
.journey-label { font: 600 12px var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--faint); margin: 64px 0 22px; }
.now-sum { color: var(--muted); font-size: 15px; margin-top: 18px; }
.also { margin-top: 16px; font-size: 14px; color: var(--ink-2); background: var(--bg-alt); border-radius: 12px; padding: 12px 14px; }
.also b { display: block; font: 600 11px var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--accent); margin-bottom: 4px; }
.cv-link { display: block; text-align: center; margin-top: 14px; font-size: 14px; font-weight: 500; color: var(--accent); text-decoration: none; }
.cv-link:hover { text-decoration: underline; }
.now-card { margin-top: 8px; display: grid; grid-template-columns: 1fr 1.5fr; gap: 40px; padding: 36px 40px; }
.now-card .tag { margin-bottom: 14px; }
.now-card h3 { font: 400 32px/1.1 var(--display); }
.now-card h3 small { display: block; font: 500 15px var(--sans); color: var(--accent); margin-top: 8px; }
.now-card .dates { color: var(--faint); font-size: 14px; margin-top: 6px; }
.now-card ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.now-card li { position: relative; padding-left: 30px; color: var(--ink-2); font-size: 15.5px; }
.now-card li::before { content: ""; position: absolute; left: 0; top: 7px; width: 16px; height: 10px; border-left: 2px solid var(--accent); border-bottom: 2px solid var(--accent); transform: rotate(-45deg) scale(.7); }
@media (max-width: 960px) {
  .journey ol { grid-template-columns: 1fr; gap: 0; }
  .journey .rail { left: 7px; right: auto; top: 8px; bottom: 8px; width: 2px; height: auto; }
  .journey .rail i { transform-origin: 50% 0; transform: scaleY(0); background: linear-gradient(180deg, var(--faint), var(--accent)); }
  .journey.in .rail i { transform: scaleY(1); }
  .stop { padding: 0 0 30px 40px; }
  .stop::before { top: 8px; }
  .now-card { grid-template-columns: 1fr; gap: 24px; padding: 26px 24px; }
}
/* newest first on mobile */
@media (max-width: 960px) { .journey ol { display: flex; flex-direction: column-reverse; } }

/* ------------------------------------------------------------------ grids */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
@media (max-width: 980px) { .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 640px) { .grid-3 { grid-template-columns: 1fr; } }

/* ------------------------------------------------------------------ principles */
.principles { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0 56px; counter-reset: pr; }
.principles div { padding: 32px 0; border-top: 1px solid var(--line); display: grid; grid-template-columns: 56px 1fr; }
.principles div::before { counter-increment: pr; content: counter(pr, decimal-leading-zero); font: 500 13px var(--mono); color: var(--accent); padding-top: 12px; }
.principles h3 { font: 400 clamp(26px, 2.8vw, 34px)/1.15 var(--display); }
.principles p { color: var(--muted); margin-top: 10px; grid-column: 2; }
@media (max-width: 820px) { .principles { grid-template-columns: 1fr; } }

/* ------------------------------------------------------------------ videos */
.videos { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.video { overflow: hidden; }
.video .screen { position: relative; aspect-ratio: 16 / 9; display: grid; place-items: center; overflow: hidden; border: 0; width: 100%; padding: 0; cursor: default;
  background: radial-gradient(circle at 30% 20%, rgba(76,201,183,.35), transparent 55%), linear-gradient(140deg, #0C1422, #14305A); color: #fff; }
.video .screen::before { content: ""; position: absolute; inset: 0; background-image: radial-gradient(rgba(255,255,255,.08) 1px, transparent 1px); background-size: 22px 22px; }
.video:nth-child(2) .screen { background: radial-gradient(circle at 70% 25%, rgba(227,167,120,.35), transparent 55%), linear-gradient(140deg, #0C1422, #2B2340); }
.video .play { position: relative; width: 72px; height: 72px; border-radius: 50%; background: rgba(255,255,255,.12); border: 1px solid rgba(255,255,255,.3);
  display: grid; place-items: center; backdrop-filter: blur(6px); transition: transform .25s var(--ease), background .25s; }
.video .play svg { width: 26px; height: 26px; margin-left: 4px; }
.video button.screen { cursor: pointer; }
.video button.screen:hover .play { transform: scale(1.08); background: rgba(255,255,255,.2); }
.video .screen .len { position: absolute; right: 14px; bottom: 12px; font: 500 12px var(--mono); background: rgba(0,0,0,.45); padding: 3px 8px; border-radius: 6px; }
.video .screen .soon { position: absolute; left: 14px; top: 14px; font: 500 12px var(--sans); background: rgba(255,255,255,.14); padding: 4px 10px; border-radius: 999px; border: 1px solid rgba(255,255,255,.2); }
.video iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.video .body { padding: 22px 24px 26px; }
.video h3 { font-size: 18px; }
.video p { color: var(--muted); font-size: 15px; margin-top: 6px; }
@media (max-width: 760px) { .videos { grid-template-columns: 1fr; } }

/* ------------------------------------------------------------------ track cards */
.track-card { display: flex; flex-direction: column; gap: 14px; padding: 26px; text-decoration: none; transition: transform .25s var(--ease), border-color .25s, box-shadow .25s; height: 100%; }
.track-card:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--accent) 45%, var(--line)); box-shadow: var(--shadow-lg); }
.track-card .top { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.icon { width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; background: var(--accent-soft); color: var(--accent); flex: none; }
.icon svg { width: 21px; height: 21px; }
.track-card h3 { font-size: 18px; }
.track-card p { color: var(--muted); font-size: 14.5px; flex: 1; }
.track-card .meta { display: flex; gap: 6px 14px; flex-wrap: wrap; font-size: 13px; color: var(--faint); padding-top: 14px; border-top: 1px solid var(--line-2); }
.track-card .meta b { color: var(--ink-2); font-weight: 500; }
.hub-cta { margin-top: 32px; display: flex; justify-content: center; }

/* ------------------------------------------------------------------ skills */
.skills { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.skills .card { padding: 22px 24px; box-shadow: none; }
.skills h3 { font-size: 15px; margin-bottom: 12px; }
.skills .chips { display: flex; flex-wrap: wrap; gap: 7px; }
.certs { color: var(--muted); margin-top: 22px; font-size: 14.5px; }
.certs b { color: var(--ink-2); font-weight: 600; }
@media (max-width: 900px) { .skills { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 580px) { .skills { grid-template-columns: 1fr; } }

/* ------------------------------------------------------------------ contact / footer */
.contact { position: relative; overflow: hidden; margin-top: 120px; background: #0F1B33; color: #fff; border-radius: 28px; padding: 72px 64px;
  display: flex; gap: 32px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.contact::after { content: ""; position: absolute; width: 520px; height: 520px; right: -140px; top: -220px; border-radius: 50%; background: radial-gradient(circle, rgba(76,201,183,.28), transparent 65%); pointer-events: none; }
:root[data-theme="dark"] .contact { background: #121D31; border: 1px solid var(--line); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .contact { background: #121D31; border: 1px solid var(--line); } }
.contact > * { position: relative; z-index: 1; }
.contact h2 { font-size: clamp(36px, 4.6vw, 56px); }
.contact p { color: #B8C0D0; margin-top: 14px; font-size: 17px; }
.contact .mail { display: inline-block; color: #86DDD0; font-weight: 500; font-size: 18px; margin-top: 22px; text-decoration: none; word-break: break-all; }
.contact .btn { background: #fff; color: #0F1B33; border-color: #fff; }
@media (max-width: 640px) { .contact { padding: 40px 24px; border-radius: 20px; } }
.footer { padding: 48px 0; color: var(--muted); font-size: 14px; }
.footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.footer a { text-decoration: none; margin-left: 18px; } .footer a:first-child { margin-left: 0; }
.footer a:hover { color: var(--ink); }

/* ================================================================== LEARNING HUB */
.hub-hero { padding: 72px 0 40px; }
.hub-hero h1 { font-size: clamp(42px, 5.6vw, 72px); margin: 22px 0 20px; max-width: 900px; }
.hub-hero .lead { color: var(--muted); font-size: 18px; max-width: 720px; }
.hub-stats { display: flex; gap: 40px; flex-wrap: wrap; margin-top: 32px; }
.hub-stats b { font: 400 40px/1 var(--display); display: block; }
.hub-stats span { color: var(--muted); font-size: 14px; }
.how { display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; margin-top: 48px; counter-reset: step; padding: 0; }
.how li { list-style: none; padding: 20px; box-shadow: none; }
.how li::before { counter-increment: step; content: counter(step, decimal-leading-zero); font: 500 12px var(--mono); color: var(--accent); }
.how b { display: block; font-weight: 600; font-size: 15.5px; margin: 8px 0 4px; }
.how span { color: var(--muted); font-size: 13.5px; line-height: 1.5; display: block; }
@media (max-width: 980px) { .how { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .how { grid-template-columns: 1fr; } }

.toolbar { position: sticky; top: 68px; z-index: 20; background: var(--bg); padding: 16px 0; border-bottom: 1px solid var(--line); margin-top: 48px; }
.toolbar .wrap { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; }
.search { flex: 1 1 280px; position: relative; }
.search input { width: 100%; height: 46px; padding: 0 16px 0 44px; border-radius: 12px; border: 1px solid var(--line); background: var(--card); color: var(--ink); font: inherit; font-size: 15px; }
.search input:focus { outline: none; border-color: var(--accent); }
.search svg { position: absolute; left: 14px; top: 13px; width: 20px; height: 20px; color: var(--faint); }
.filters { display: flex; gap: 8px; flex-wrap: wrap; }
.filters button { font: 500 13.5px var(--sans); border: 1px solid var(--line); background: var(--card); color: var(--muted); padding: 8px 14px; border-radius: 999px; cursor: pointer; }
.filters button:hover { color: var(--ink); border-color: var(--faint); }
.filters button[aria-pressed="true"] { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.cat { padding-top: 64px; scroll-margin-top: 150px; }
.cat-head { display: flex; align-items: center; gap: 16px; margin-bottom: 24px; }
.cat-head h2 { font-size: 34px; }
.cat-head p { color: var(--muted); font-size: 15px; margin-top: 4px; }
.empty { display: none; padding: 60px 0; text-align: center; color: var(--muted); }
.paths { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.path { padding: 24px 26px; }
.path h3 { font-size: 17px; margin-bottom: 14px; }
.path ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.path li { display: flex; align-items: center; gap: 8px; }
.path li + li::before { content: "→"; color: var(--faint); }
.path a { font-size: 13.5px; text-decoration: none; background: var(--chip); padding: 5px 12px; border-radius: 999px; }
.path a:hover { background: var(--accent-soft); color: var(--accent-ink); }
@media (max-width: 820px) { .paths { grid-template-columns: 1fr; } }
.note { margin-top: 40px; padding: 18px 22px; border-left: 2px solid var(--accent); background: var(--card); border-radius: 0 12px 12px 0; color: var(--muted); font-size: 14.5px; }

/* ================================================================== TRACK PAGE */
.doc { display: grid; grid-template-columns: 272px minmax(0, 1fr); gap: 56px; max-width: 1320px; margin: 0 auto; padding: 0 24px; }
.side { position: sticky; top: 68px; align-self: start; max-height: calc(100vh - 68px); overflow-y: auto; padding: 28px 10px 40px 0; border-right: 1px solid var(--line); }
.side .filter { width: 100%; height: 38px; padding: 0 12px; border-radius: 10px; border: 1px solid var(--line); background: var(--card); color: var(--ink); font: inherit; font-size: 14px; margin-bottom: 18px; }
.side .filter:focus { outline: none; border-color: var(--accent); }
.main { padding: 40px 0; min-width: 0; }
.crumbs { font: 12.5px var(--mono); color: var(--faint); }
.crumbs a { text-decoration: none; color: var(--accent); }
.main h1 { font-size: clamp(38px, 4.8vw, 60px); margin: 18px 0 18px; max-width: 900px; }
.pills { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 24px; }
.main .summary { font-size: 18px; color: var(--muted); max-width: 820px; }
.facts { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-top: 34px; max-width: 980px; }
.facts .card { padding: 24px 26px; box-shadow: none; }
.facts h2 { font: 600 15px var(--sans); margin-bottom: 10px; }
.facts ul { margin: 0; padding-left: 20px; color: var(--muted); }
.facts li { margin: 6px 0; }
.facts p { color: var(--muted); }
@media (max-width: 760px) { .facts { grid-template-columns: 1fr; } }
.main h2.h { font-size: 38px; margin: 64px 0 8px; }
.main .sub { color: var(--muted); margin-bottom: 22px; }
.sec { margin-top: 28px; max-width: 980px; }
.sec h3 { font: 600 12px var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--accent); margin-bottom: 12px; }
.mods { list-style: none; margin: 0; padding: 0; border: 1px solid var(--line); border-radius: var(--radius); background: var(--card); overflow: hidden; }
.mods li { display: grid; grid-template-columns: 48px 1fr auto; gap: 14px; align-items: center; padding: 16px 20px; border-top: 1px solid var(--line-2); }
.mods li:first-child { border-top: 0; }
.mods .n { font: 500 12.5px var(--mono); color: var(--faint); }
.mods b { display: block; font-weight: 500; font-size: 15.5px; }
.mods span { color: var(--muted); font-size: 14px; }
@media (max-width: 560px) { .mods li { grid-template-columns: 34px 1fr; } .mods .tag { grid-column: 2; justify-self: start; } }
.scen { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; max-width: 980px; }
.scen .card { padding: 22px 24px; border-left: 2px solid var(--warm); box-shadow: none; }
.scen b { display: block; font: 400 22px/1.2 var(--display); margin-bottom: 8px; }
.scen p { color: var(--muted); font-size: 14.5px; }
@media (max-width: 760px) { .scen { grid-template-columns: 1fr; } }
.pager { display: flex; justify-content: space-between; gap: 16px; margin-top: 64px; max-width: 980px; }
.pager a { flex: 1; padding: 18px 22px; text-decoration: none; box-shadow: none; }
.pager a:hover { border-color: var(--accent); }
.pager small { color: var(--faint); font-size: 13px; display: block; }
.pager b { font: 400 21px var(--display); }
.pager .next { text-align: right; }
.side-toggle { display: none; }
@media (max-width: 960px) {
  .doc { grid-template-columns: 1fr; gap: 0; padding: 0 16px; }
  .side { position: static; max-height: none; border-right: 0; border-bottom: 1px solid var(--line); padding: 16px 0; display: none; }
  .side.open { display: block; }
  .side-toggle { display: inline-flex; margin-top: 20px; font: 500 14px var(--sans); background: var(--card); border: 1px solid var(--line); color: var(--ink); padding: 9px 16px; border-radius: 10px; cursor: pointer; }
}

/* ------------------------------------------------------------------ work areas */
.area { padding: 30px 30px 32px; transition: transform .25s var(--ease), box-shadow .25s, border-color .25s; }
.area:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: color-mix(in srgb, var(--accent) 35%, var(--line)); }
.area .mark { display: inline-grid; place-items: center; min-width: 46px; height: 46px; padding: 0 10px; border-radius: 13px;
  background: var(--accent-soft); color: var(--accent); font: 600 15px var(--sans); letter-spacing: -.01em; }
.area h3 { font-size: 19px; margin: 22px 0 10px; }
.area p { color: var(--muted); font-size: 15px; line-height: 1.6; }
.area ul { margin: 20px 0 0; padding: 0; list-style: none; display: grid; gap: 9px; }
.area li { position: relative; padding-left: 18px; font-size: 14.5px; color: var(--ink-2); }
.area li::before { content: ""; position: absolute; left: 2px; top: .7em; width: 5px; height: 5px; border-radius: 50%; background: var(--faint); }

/* ------------------------------------------------------------------ area colours */
[data-c] { --cc: var(--c); --cs: color-mix(in srgb, var(--c) 11%, transparent); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) [data-c] { --cc: color-mix(in srgb, var(--c) 55%, #fff); --cs: color-mix(in srgb, var(--c) 22%, transparent); } }
:root[data-theme="dark"] [data-c] { --cc: color-mix(in srgb, var(--c) 55%, #fff); --cs: color-mix(in srgb, var(--c) 22%, transparent); }
[data-c] .icon { background: var(--cs); color: var(--cc); }
.track-card[data-c]:hover { border-color: color-mix(in srgb, var(--c) 45%, var(--line)); }
.track-card[data-c] { border-top: 3px solid var(--cc); }
.cat-head[data-c] h2 { color: var(--ink); }
.main[data-c] .sec h3, .main[data-c] .mods .n { color: var(--cc); }
.main[data-c] .mods li:target { background: var(--cs); }
.mods li { scroll-margin-top: 90px; }
.area-chip { display: inline-flex; align-items: center; gap: 6px; color: var(--cc); }
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--cc); flex: none; }

/* ------------------------------------------------------------------ sidebar: areas → tracks → lessons */
.side .grp { margin-top: 22px; }
.side .grp:first-of-type { margin-top: 4px; }
.side h4 { display: flex; align-items: center; gap: 8px; font: 600 11px var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--cc); margin: 0 0 6px 8px; }
.side ul { list-style: none; margin: 0; padding: 0; }
.side .row { display: flex; align-items: flex-start; gap: 2px; border-radius: 9px; }
.side .row > a { flex: 1; padding: 7px 8px 7px 10px; border-radius: 9px; text-decoration: none; font-size: 14px; color: var(--ink-2); line-height: 1.4; }
.side .row:hover { background: var(--chip); }
.side .trk.cur > .row { background: var(--cs); box-shadow: inset 3px 0 0 var(--cc); }
.side .trk.cur > .row > a { color: var(--ink); font-weight: 600; }
.side .tg { flex: none; width: 30px; height: 32px; display: grid; place-items: center; border: 0; background: none; color: var(--faint); cursor: pointer; border-radius: 8px; }
.side .tg:hover { color: var(--cc); }
.side .tg svg { width: 15px; height: 15px; transition: transform .2s var(--ease); }
.side .tg[aria-expanded="true"] svg { transform: rotate(90deg); color: var(--cc); }
.side .subs { margin: 6px 0 12px 14px; padding-left: 10px; border-left: 2px solid var(--cs); }
.side .subs .sec-name { font: 600 10.5px var(--sans); letter-spacing: .1em; text-transform: uppercase; color: var(--faint); margin: 10px 0 3px 6px; }
.side .subs .sec-name:first-child { margin-top: 2px; }
.side .subs a { display: flex; gap: 8px; padding: 4px 6px; border-radius: 6px; font-size: 13px; line-height: 1.4; color: var(--muted); text-decoration: none; }
.side .subs a:hover { background: var(--chip); color: var(--ink); }
.side .subs a span { font: 500 11px/1.6 var(--mono); color: var(--cc); flex: none; }
.side mark { background: color-mix(in srgb, var(--c, #0F766E) 25%, transparent); color: inherit; border-radius: 3px; }

/* ================================================================== LESSONS */
.lesson-no { font: 500 12.5px var(--mono); color: var(--cc, var(--accent)); margin-top: 18px; }
.main.lesson h1 { margin-top: 8px; }
.main .start { margin-top: 26px; }
.toc { max-width: 860px; margin: 26px 0 8px; padding: 18px 22px; box-shadow: none; }
.toc b { font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--faint); font-weight: 600; }
.toc ol { margin: 10px 0 0; padding-left: 20px; columns: 2; column-gap: 32px; font-size: 14.5px; }
.toc li { margin: 3px 0; break-inside: avoid; }
.toc a { text-decoration: none; color: var(--ink-2); }
.toc a:hover { color: var(--cc, var(--accent)); }
@media (max-width: 640px) { .toc ol { columns: 1; } }

.prose { max-width: 860px; font-size: 16.5px; line-height: 1.75; color: var(--ink-2); }
.prose > * + * { margin-top: 18px; }
.prose h2 { font-size: clamp(30px, 3.4vw, 40px); margin-top: 56px; color: var(--ink); scroll-margin-top: 90px; }
.prose h3 { font-size: 19px; margin-top: 34px; color: var(--ink); }
.prose p, .prose li { color: var(--ink-2); }
.prose strong { color: var(--ink); font-weight: 600; }
.prose a { color: var(--cc, var(--accent)); text-underline-offset: 3px; }
.prose ul, .prose ol { padding-left: 24px; }
.prose li + li { margin-top: 6px; }
.prose li::marker { color: var(--cc, var(--accent)); }
.prose :not(pre) > code { font: 500 .88em var(--mono); background: var(--chip); color: var(--ink); padding: 2px 6px; border-radius: 6px; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 40px 0; }
.prose table { border-collapse: collapse; width: 100%; font-size: 15px; background: var(--card); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; display: block; overflow-x: auto; }
.prose th { text-align: left; font-weight: 600; color: var(--ink); background: var(--bg-alt); }
.prose th, .prose td { padding: 10px 14px; border-top: 1px solid var(--line-2); vertical-align: top; }
.prose blockquote { margin: 0; padding: 4px 0 4px 18px; border-left: 3px solid var(--cc, var(--accent)); color: var(--muted); font-style: italic; }

/* code blocks (always dark, like a terminal) */
.hl { position: relative; background: #0D1117 !important; border-radius: 12px; border: 1px solid #1F2733; }
.hl pre { margin: 0; padding: 16px 18px; overflow-x: auto; font: 13.5px/1.7 var(--mono); color: #E6EDF3; }
.hl .copy-code { position: absolute; top: 8px; right: 8px; font: 500 11.5px var(--sans); color: #9FB0C8; background: #161B22; border: 1px solid #30363D; border-radius: 7px; padding: 4px 9px; cursor: pointer; opacity: 0; transition: opacity .2s; }
.hl:hover .copy-code, .hl .copy-code:focus { opacity: 1; }
.hl .copy-code.done { color: #7DD3C7; }

/* callouts */
.admonition { border-radius: 14px; padding: 16px 20px; border: 1px solid var(--line); background: var(--card); }
.admonition > * + * { margin-top: 10px; }
.admonition-title { font-weight: 600; color: var(--ink) !important; display: flex; gap: 8px; align-items: center; margin: 0; }
.admonition.kid { background: linear-gradient(135deg, #FFF7E6, #FFF1F2); border-color: #F6D9A8; }
.admonition.lab { background: color-mix(in srgb, var(--cc, #0F766E) 7%, var(--card)); border-color: color-mix(in srgb, var(--cc, #0F766E) 30%, var(--line)); }
.admonition.pro { background: #F3F0FF; border-color: #D9D0FB; }
.admonition.tip { background: #ECFDF5; border-color: #BCEBD4; }
.admonition.warning { background: #FFF4ED; border-color: #F8C9A8; }
.admonition.scenario { background: #FFF1F2; border-color: #F7C6CD; }
.admonition.note { background: var(--bg-alt); }
:root[data-theme="dark"] .admonition.kid, :root[data-theme="dark"] .admonition.pro, :root[data-theme="dark"] .admonition.tip,
:root[data-theme="dark"] .admonition.warning, :root[data-theme="dark"] .admonition.scenario { background: var(--card); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .admonition.kid, :root:not([data-theme="light"]) .admonition.pro,
  :root:not([data-theme="light"]) .admonition.tip, :root:not([data-theme="light"]) .admonition.warning, :root:not([data-theme="light"]) .admonition.scenario { background: var(--card); } }
.admonition.kid { border-left: 4px solid #F59E0B; } .admonition.pro { border-left: 4px solid #7C3AED; } .admonition.tip { border-left: 4px solid #10B981; }
.admonition.warning { border-left: 4px solid #F97316; } .admonition.scenario { border-left: 4px solid #E11D48; } .admonition.lab { border-left: 4px solid var(--cc, #0F766E); }

/* cheat sheet */
.quiz { max-width: 860px; margin-top: 8px; }
.cheatsheet h2, .quiz h2 { font-size: clamp(30px, 3.4vw, 40px); display: flex; gap: 12px; align-items: center; scroll-margin-top: 90px; }
.cs-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(380px, 1fr)); gap: 16px; margin-top: 24px; max-width: 1100px; }
@media (max-width: 520px) { .cs-grid { grid-template-columns: 1fr; } }
.cs-group { background: var(--card); border: 1px solid var(--line); border-radius: 14px; overflow: hidden; }
.cs-group h3 { font-size: 13px; letter-spacing: .1em; text-transform: uppercase; color: var(--cc, var(--accent)); padding: 12px 16px; background: var(--cs, var(--bg-alt)); }
.cs-group table { width: 100%; border-collapse: collapse; font-size: 14.5px; }
.cs-group td { padding: 9px 16px; border-top: 1px solid var(--line-2); vertical-align: top; color: var(--ink-2); }
.cs-group td:first-child { width: 52%; }
.cs-group code { font: 500 13px var(--mono); color: var(--ink); white-space: pre-wrap; word-break: break-word; }
@media (max-width: 640px) { .cs-group td:first-child { white-space: normal; width: 55%; } }

/* quiz */
.quiz .sub { color: var(--muted); margin: 6px 0 18px; }
.qs { list-style: none; margin: 0; padding: 0; display: grid; gap: 16px; }
.q { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 18px 20px; }
.qq { font-weight: 600; color: var(--ink); }
.qq span { color: var(--cc, var(--accent)); font-family: var(--mono); font-size: 13px; margin-right: 4px; }
.opts { list-style: none; margin: 12px 0 0; padding: 0; display: grid; gap: 8px; }
.opts button { width: 100%; text-align: left; display: flex; gap: 12px; align-items: flex-start; padding: 10px 14px; border-radius: 10px; border: 1px solid var(--line);
  background: var(--bg); color: var(--ink-2); font: inherit; font-size: 15px; cursor: pointer; transition: border-color .15s, background .15s; }
.opts button:hover:not(:disabled) { border-color: var(--cc, var(--accent)); }
.opts .k { font: 600 12px/1.9 var(--mono); color: var(--faint); flex: none; }
.opts button.right { border-color: #10B981; background: color-mix(in srgb, #10B981 12%, var(--card)); color: var(--ink); }
.opts button.wrong { border-color: #F43F5E; background: color-mix(in srgb, #F43F5E 10%, var(--card)); }
.opts button:disabled { cursor: default; }
.why { margin-top: 12px; font-size: 14.5px; color: var(--muted); }
.why summary { cursor: pointer; color: var(--faint); font-size: 13.5px; }
.js .why summary { display: none; }
.why p { margin-top: 6px; }
.score { margin-top: 18px; font-weight: 600; color: var(--ink); }

/* track page: ready lessons */
.mods li.ready .mod-link { text-decoration: none; color: inherit; display: block; }
.mods li.ready:hover { background: var(--cs, var(--bg-alt)); }
.mods li.ready b { color: var(--ink); }
.side .subs li.todo a { opacity: .6; }
.side .subs a[aria-current="page"] { background: var(--cs); color: var(--ink); font-weight: 600; }
.main.lesson .summary { margin-bottom: 16px; }

/* ------------------------------------------------------------------ lesson tabs: Lesson · Cheat sheet · Check yourself */
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin: 20px 0 22px; padding: 5px; background: var(--chip); border-radius: 14px; width: fit-content; max-width: 100%; }
.tabs a { display: inline-flex; align-items: center; gap: 8px; padding: 9px 16px; border-radius: 10px; text-decoration: none; font-size: 14.5px; font-weight: 500; color: var(--muted); white-space: nowrap; }
.tabs a:hover { color: var(--ink); }
.tabs a[aria-current="page"] { background: var(--card); color: var(--ink); box-shadow: 0 1px 3px rgba(15, 27, 51, .12); }
.tabs small { font: 600 11px var(--mono); background: var(--cs, var(--accent-soft)); color: var(--cc, var(--accent)); padding: 1px 7px; border-radius: 99px; }
.main.lesson .summary { margin-bottom: 14px; }
.print-btn { margin-left: 8px; font: 500 13.5px var(--sans); border: 1px solid var(--line); background: var(--card); color: var(--ink); padding: 5px 12px; border-radius: 8px; cursor: pointer; vertical-align: 2px; }
.print-btn:hover { border-color: var(--cc, var(--accent)); }
.cs-lesson { margin-top: 40px; max-width: 1100px; }
.cs-lesson h2 { font-size: 28px; }
.cs-lesson h2 a { text-decoration: none; color: var(--ink); }
.cs-lesson h2 a:hover { color: var(--cc); }
.q-src { display: inline-block; margin-top: 6px; font-size: 13.5px; color: var(--cc, var(--accent)); }
.retry { margin-top: 12px; height: 42px; }
.sec-review { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 16px; margin: 12px 0 0; font-size: 14.5px; }
.sec-review span { color: var(--muted); }
.sec-review a { text-decoration: none; font-weight: 500; color: var(--cc, var(--accent)); background: var(--cs, var(--accent-soft)); padding: 6px 12px; border-radius: 999px; }
.sec-review a:hover { text-decoration: underline; }

/* ------------------------------------------------------------------ print: cheat sheets on paper */
@media print {
  .nav, .progress, .side, .side-toggle, .tabs, .pager, .note, .footer, .print-btn, .toc { display: none !important; }
  body { background: #fff; color: #000; font-size: 11pt; }
  .doc { display: block; padding: 0; }
  .main { padding: 0; }
  .main h1 { font-size: 24pt; margin: 0 0 6pt; }
  .cs-grid { grid-template-columns: 1fr 1fr; gap: 8pt; }
  .cs-group, .q { break-inside: avoid; box-shadow: none; }
  .hl { border: 1px solid #ccc; }
}

/* cheat sheet rows: command on its own line (never broken mid-word), description underneath */
.cs-grid { align-items: start; }
.cs-group tr { display: block; padding: 10px 16px; border-top: 1px solid var(--line-2); }
.cs-group td { display: block; padding: 0; border: 0; width: auto !important; }
.cs-group td:first-child { overflow-x: auto; white-space: nowrap; scrollbar-width: thin; }
.cs-group td:first-child code { white-space: pre; word-break: normal; font-size: 13.5px; }
.cs-group td + td { margin-top: 3px; font-size: 14px; color: var(--muted); }
@media print { .cs-group td:first-child { white-space: pre-wrap; } }
@media (max-width: 520px) { .tabs { flex-wrap: nowrap; overflow-x: auto; gap: 2px; width: 100%; } .tabs a { padding: 8px 10px; font-size: 13.5px; gap: 5px; } }

/* ================================================================== COURSE LAYOUT: topic panel | content | all courses */
.topic-bar { position: sticky; top: 68px; z-index: 40; display: flex; align-items: center; gap: 10px; padding: 10px max(24px, calc((100vw - 1480px) / 2 + 24px));
  background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line); font-size: 14px; white-space: nowrap; overflow: hidden; }
.topic-bar a { color: var(--ink); font-weight: 600; text-decoration: none; overflow: hidden; text-overflow: ellipsis; }
.topic-bar a:hover { color: var(--cc); }
.topic-bar .tb-sep { color: var(--faint); }
.topic-bar .tb-cur { color: var(--muted); overflow: hidden; text-overflow: ellipsis; }
.topic-bar .side-toggle { margin: 0 0 0 auto; padding: 5px 12px; font-size: 13px; }
html { scroll-padding-top: 130px; }
.mods li, .prose h2, .cheatsheet h2 { scroll-margin-top: 130px; }

.doc3 { grid-template-columns: 256px minmax(0, 1fr) 224px; gap: 44px; max-width: 1480px; }
.doc3 .side, .courses-panel { top: 113px; max-height: calc(100vh - 113px); }
.doc3 .main { padding-top: 32px; }

/* left: this course */
.topic-panel { padding: 24px 8px 40px 0; }
.tp-head { padding: 0 6px 14px 8px; border-bottom: 1px solid var(--line); margin-bottom: 10px; }
.tp-title { display: block; font: 600 16px/1.35 var(--sans); color: var(--ink); text-decoration: none; padding: 2px 0 10px; }
.tp-title:hover, .tp-title[aria-current="page"] { color: var(--cc); }
.tp-kw { display: flex; flex-wrap: wrap; gap: 5px; }
.tp-kw em, .kw em { font-style: normal; font-size: 12px; color: var(--cc); background: var(--cs); padding: 2px 9px; border-radius: 999px; white-space: nowrap; }
.tp-list { list-style: none; margin: 0; padding: 0; }
.tp-list .sec-name { font: 600 10.5px var(--sans); letter-spacing: .1em; text-transform: uppercase; color: var(--faint); margin: 16px 0 5px 8px; }
.tp-list a { display: flex; gap: 9px; padding: 6px 8px; border-radius: 8px; font-size: 13.5px; line-height: 1.4; color: var(--ink-2); text-decoration: none; }
.tp-list a:hover { background: var(--chip); color: var(--ink); }
.tp-list a span { font: 500 11px/1.75 var(--mono); color: var(--cc); flex: none; width: 18px; }
.tp-list li.todo a { color: var(--faint); }
.tp-list li.todo a span { opacity: .6; }
.tp-list a[aria-current="page"] { background: var(--cs); color: var(--ink); font-weight: 600; box-shadow: inset 3px 0 0 var(--cc); }
.tp-list li.review a { margin-top: 2px; color: var(--ink); font-weight: 500; border: 1px dashed color-mix(in srgb, var(--cc) 40%, var(--line)); }
.tp-list li.review a span { font-family: var(--sans); }

/* right: all courses */
.courses-panel { position: sticky; align-self: start; overflow-y: auto; padding: 24px 0 40px 18px; border-left: 1px solid var(--line); }
.cp-title { font: 600 11px var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--faint); margin-bottom: 4px; }
.cp-grp { margin-top: 16px; }
.cp-grp h4 { display: flex; align-items: center; gap: 7px; font: 600 11px var(--sans); letter-spacing: .08em; text-transform: uppercase; color: var(--cc); margin: 0 0 4px; }
.cp-grp ul { list-style: none; margin: 0; padding: 0; }
.cp-grp a { display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 5px 8px; margin-left: -8px; border-radius: 7px; font-size: 13px; line-height: 1.35; color: var(--muted); text-decoration: none; }
.cp-grp a:hover { background: var(--chip); color: var(--ink); }
.cp-grp a[aria-current="page"] { color: var(--ink); font-weight: 600; background: var(--cs); }
.cp-grp .live { width: 7px; height: 7px; border-radius: 50%; background: #10B981; flex: none; }
.cp-all { display: block; margin-top: 20px; font-size: 13px; font-weight: 500; color: var(--accent); text-decoration: none; }

/* key words */
.kw { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin: 4px 0 20px; max-width: 860px; }
.kw span { font: 600 11px var(--sans); letter-spacing: .1em; text-transform: uppercase; color: var(--faint); margin-right: 4px; }
.kw em { font-size: 13px; padding: 3px 11px; }

/* track page: section wrap-up row */
.mods li.review-row { background: var(--cs); }
.mods li.review-row .n { font-family: var(--sans); font-size: 16px; }

@media (max-width: 1200px) {
  .doc3 { grid-template-columns: 240px minmax(0, 1fr); }
  .courses-panel { position: static; grid-column: 2; max-height: none; border-left: 0; border-top: 1px solid var(--line); padding: 24px 0 8px; columns: 2; column-gap: 28px; }
  .courses-panel .cp-grp { break-inside: avoid; }
}
@media (min-width: 961px) { .topic-bar .side-toggle { display: none; } }
@media (max-width: 960px) {
  .doc3 { grid-template-columns: 1fr; }
  .doc3 .side { position: static; max-height: none; }
  .courses-panel { grid-column: 1; columns: 1; }
  .topic-bar { padding: 8px 16px; }
}
@media print { .topic-bar, .courses-panel { display: none !important; } }
.topic-bar { background: var(--bg); backdrop-filter: none; -webkit-backdrop-filter: none; }
.nav { background: color-mix(in srgb, var(--bg) 96%, transparent); }

/* right panel: collapsible areas (accordion) */
.cp-grp { margin-top: 6px; border-bottom: 1px solid var(--line-2); padding-bottom: 6px; }
.cp-grp summary { list-style: none; display: flex; align-items: center; gap: 8px; cursor: pointer; padding: 7px 4px; border-radius: 8px;
  font: 600 11px var(--sans); letter-spacing: .08em; text-transform: uppercase; color: var(--cc); line-height: 1.35; }
.cp-grp summary::-webkit-details-marker { display: none; }
.cp-grp summary::after { content: "›"; margin-left: auto; font-size: 15px; color: var(--faint); transition: transform .2s var(--ease); }
.cp-grp[open] summary::after { transform: rotate(90deg); }
.cp-grp summary:hover { background: var(--chip); }
.cp-grp summary small { font: 500 11px var(--mono); color: var(--faint); letter-spacing: 0; }
.cp-grp ul { padding: 2px 0 4px 8px !important; }

/* analogy box without a title: keep the box, show the icon beside the text */
.admonition.kid:not(:has(.admonition-title)) { position: relative; padding-left: 52px; }
.admonition.kid:not(:has(.admonition-title))::before { content: "🧒"; position: absolute; left: 18px; top: 15px; font-size: 20px; line-height: 1; }

/* ================================================================== SKETCHES (inline SVG diagrams, scripts/sketches.py) */
.sketch { margin: 28px 0; padding: 18px 16px 12px; background: var(--card); border: 1px solid var(--line); border-radius: 14px; }
.sketch svg { display: block; width: 100%; height: auto; }
.sketch figcaption { margin-top: 10px; font-size: 13px; line-height: 1.5; color: var(--muted); text-align: center; }
.sketch text { font-family: var(--sans); }
.sketch .tb { font-size: 13.5px; font-weight: 600; fill: var(--ink); }
.sketch .ts { font-size: 11.5px; fill: var(--muted); }
.sketch .tz { font-size: 11px; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; fill: var(--faint); }
.sketch .tl { font-size: 11px; fill: var(--ink-2); font-style: italic; }
.sketch .tn { font-size: 11px; font-weight: 700; fill: var(--card); }
.sketch .box { fill: var(--bg-alt); stroke: var(--line); stroke-width: 1.5; }
.sketch .soft { fill: var(--card); stroke: var(--line); stroke-width: 1.5; stroke-dasharray: 4 3; }
.sketch .acc { fill: var(--cs, var(--accent-soft)); stroke: var(--cc, var(--accent)); stroke-width: 1.6; }
.sketch .zone { fill: none; stroke: var(--faint); stroke-width: 1.2; stroke-dasharray: 6 5; }
.sketch .num { fill: var(--cc, var(--accent)); }
.sketch .flow { fill: none; stroke: var(--cc, var(--accent)); stroke-width: 2; }
.sketch .tls { fill: none; stroke: var(--cc, var(--accent)); stroke-width: 4.5; }
.sketch .line { fill: none; stroke: var(--muted); stroke-width: 1.5; }
.sketch .back, .sketch .dash { fill: none; stroke: var(--muted); stroke-width: 1.5; stroke-dasharray: 5 4; }
.sketch .back { stroke: var(--cc, var(--accent)); opacity: .7; }
.sketch .deny { fill: none; stroke: #DC2626; stroke-width: 3; stroke-linecap: round; }
.sketch .ah-flow, .sketch .ah-tls, .sketch .ah-back { fill: var(--cc, var(--accent)); }
.sketch .ah-line, .sketch .ah-dash { fill: var(--muted); }
@media (max-width: 640px) { .sketch { padding: 10px 6px 8px; margin: 20px -4px; } }
@media print { .sketch { break-inside: avoid; } }

/* ================================================================== HUB: search first, compact hero with scrolling "how" cards */
.toolbar.hub-top { margin-top: 0; }
.hub-hero { padding: 36px 0 12px; }
.hub-grid { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); gap: 40px; align-items: center; }
.hub-hero h1 { font-size: clamp(34px, 3.8vw, 52px); margin: 14px 0 14px; }
.hub-hero .lead { font-size: 16.5px; }
.hub-stats { gap: 32px; margin-top: 22px; }
.hub-stats b { font-size: 34px; }
.how-rail { overflow: hidden; padding: 8px 0;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
          mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent); }
.how-rail .how { display: flex; gap: 14px; width: max-content; margin: 0; animation: how-scroll 38s linear infinite; }
.how-rail:hover .how { animation-play-state: paused; }
.how-rail .how li { width: 210px; flex: none; padding: 18px 18px 20px; }
.how-rail .how li::before { content: none; }
.how-rail .how em { font: 500 12px var(--mono); font-style: normal; color: var(--accent); }
@keyframes how-scroll { to { transform: translateX(calc(-50% - 7px)); } }
@media (prefers-reduced-motion: reduce) {
  .how-rail { overflow-x: auto; } .how-rail .how { animation: none; }
  .how-rail .how li[aria-hidden="true"] { display: none; }
}
@media (max-width: 980px) { .hub-grid { grid-template-columns: 1fr; gap: 20px; } }

/* ================================================================== SITE SEARCH (dropdown + results page) */
.ss { position: relative; }
.ss label { display: block; position: relative; }
.ss-nav { flex: 0 1 320px; margin: 0 18px 0 auto; }
.ss-nav input { width: 100%; height: 38px; padding: 0 12px 0 36px; border-radius: 10px; border: 1px solid var(--line);
  background: var(--card); color: var(--ink); font: inherit; font-size: 14px; }
.ss-nav input:focus { outline: none; border-color: var(--accent); }
.ss-nav svg { position: absolute; left: 11px; top: 10px; width: 17px; height: 17px; color: var(--faint); }
.ss-drop { position: absolute; left: 0; right: 0; top: calc(100% + 6px); z-index: 80; background: var(--card);
  border: 1px solid var(--line); border-radius: 12px; box-shadow: var(--shadow-lg); max-height: min(70vh, 540px);
  overflow-y: auto; padding: 6px; text-align: left; }
.ss-nav .ss-drop { left: 0; right: auto; width: min(560px, calc(100vw - 32px)); }
.ss-item { display: block; padding: 9px 10px; border-radius: 8px; text-decoration: none; color: var(--ink-2); }
.ss-item b { display: block; font-size: 14px; font-weight: 600; color: var(--ink); line-height: 1.4; }
.ss-item .ss-sec, .sr-list .ss-sec { font-weight: 500; color: var(--muted); }
.ss-item small { display: block; font-size: 11.5px; color: var(--accent); margin: 2px 0 3px; }
.ss-snip { display: block; font-size: 12.5px; line-height: 1.5; color: var(--muted); }
.ss-item:hover, .ss-item[aria-selected="true"] { background: var(--chip); }
.ss mark, .sr-list mark { background: color-mix(in srgb, var(--accent) 24%, transparent); color: inherit; border-radius: 3px; padding: 0 1px; }
.ss-all { display: flex; justify-content: space-between; align-items: center; padding: 10px; margin-top: 4px;
  border-top: 1px solid var(--line-2); font-size: 13px; font-weight: 500; color: var(--accent); text-decoration: none; }
.ss-all kbd, .ss-msg code, .search-page .lead code { font: 500 11.5px var(--mono); border: 1px solid var(--line); border-radius: 5px; padding: 1px 6px; background: var(--chip); }
.ss-msg { padding: 12px; font-size: 13.5px; color: var(--muted); margin: 0; }
.ss-mobile { display: none; color: var(--ink-2); padding: 8px; margin-left: auto; }
.ss-mobile svg { width: 20px; height: 20px; }
.search-page { padding-top: 48px; }
.search-page .ss.big { max-width: 780px; margin: 26px 0 6px; }
.sr-count { color: var(--muted); margin: 16px 0 12px; }
.sr-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; max-width: 920px; }
.sr-list li { padding: 14px 18px; box-shadow: none; }
.sr-list a { text-decoration: none; color: var(--ink); }
.sr-list a:hover b { color: var(--accent); }
.sr-list b { font-size: 16px; font-weight: 600; }
.sr-list small { display: block; color: var(--accent); font-size: 12px; margin: 3px 0 6px; }
.sr-list p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.6; }
.sr-more { margin-top: 16px; }
@media (max-width: 900px) { .ss-nav { display: none; } .ss-mobile { display: inline-flex; } }
.search-page h1 { font-size: clamp(34px, 4.2vw, 54px); margin: 14px 0 12px; }

/* ================================================================== ARTICLES (LinkedIn cards, auto-scrolling rail) */
.art-topics { display: flex; flex-wrap: wrap; gap: 8px; margin: -8px 0 18px; }
.art-topics button { font: 500 13.5px var(--sans); border: 1px solid var(--line); background: var(--card); color: var(--muted);
  padding: 7px 14px; border-radius: 999px; cursor: pointer; }
.art-topics button:hover { color: var(--ink); border-color: var(--faint); }
.art-topics button[aria-pressed="true"] { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.art-rail { position: relative; overflow: hidden; padding: 4px 0 16px; cursor: grab; touch-action: pan-y; outline: none;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 3%, #000 97%, transparent);
          mask-image: linear-gradient(90deg, transparent, #000 3%, #000 97%, transparent); }
.art-rail.dragging { cursor: grabbing; user-select: none; }
.art-rail:focus-visible { box-shadow: 0 0 0 2px var(--accent); border-radius: 12px; }
.art-track { display: flex; gap: 18px; width: max-content; padding: 0 2px; will-change: transform; }
.art-card { flex: 0 0 320px; display: flex; flex-direction: column; overflow: hidden; padding: 0;
  text-decoration: none; color: inherit; transition: transform .25s var(--ease), box-shadow .25s var(--ease); }
.art-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.art-card[hidden] { display: none; }
.art-img { display: block; aspect-ratio: 16 / 9; background: var(--bg-alt); overflow: hidden; border-bottom: 1px solid var(--line); }
.art-img img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform .4s var(--ease); }
.art-card:hover .art-img img { transform: scale(1.04); }
.art-body { display: flex; flex-direction: column; gap: 6px; padding: 16px 18px 18px; flex: 1; }
.art-topic { display: inline-flex; align-items: center; gap: 6px; font: 600 11px var(--sans); letter-spacing: .08em; text-transform: uppercase; color: var(--cc); }
.art-topic .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--cc); }
.art-title { font-size: 16px; line-height: 1.35; font-weight: 600; color: var(--ink); }
.art-sub { font-size: 13.5px; line-height: 1.5; color: var(--muted); }
.art-meta { margin-top: auto; padding-top: 8px; font-size: 12.5px; color: var(--accent); font-weight: 500; }
@media (max-width: 520px) { .art-card { flex-basis: 82vw; } }
.footer .privacy { flex-basis: 100%; font-size: 12px; color: var(--faint); margin-top: 6px; }

/* ---------------------------------------------------------------- blog */
.blog-page h1 { font-size: clamp(40px, 5.4vw, 68px); margin: 14px 0 14px; }
.blog-page .lead { max-width: 760px; }
.blog-topics { margin: 28px 0 22px; }
.post-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 20px; }
.post-item[hidden] { display: none; }
.post-card { height: 100%; display: flex; flex-direction: column; overflow: hidden; padding: 0; text-decoration: none; }
.post-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.post-card:hover .art-img img { transform: scale(1.04); }
.blog-feed { margin-top: 36px; font-size: 14px; color: var(--muted); }
.blog-feed a { color: var(--accent); }
.post { max-width: 940px; margin: 0 auto; padding: 0 24px 40px; }
.post .main { padding-top: 32px; }
.post-meta { font-size: 14px; color: var(--faint); margin: 10px 0 22px; }
.post-meta a { color: var(--cc, var(--accent)); }
.post-cover { margin: 0 0 22px; border: 1px solid var(--line); border-radius: 16px; overflow: hidden; background: var(--bg-alt); max-width: 860px; }
.post-cover img { display: block; width: 100%; height: auto; max-height: 460px; object-fit: cover; }
.related { max-width: 860px; margin-top: 48px; padding: 20px 24px; box-shadow: none; border-left: 3px solid var(--cc, var(--accent)); }
.related b { font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--faint); font-weight: 600; }
.related ul { list-style: none; margin: 10px 0 0; padding: 0; }
.related li + li { margin-top: 6px; }
.related a { color: var(--cc, var(--accent)); text-decoration: none; font-weight: 500; }
.related a:hover { text-decoration: underline; text-underline-offset: 3px; }
.post .pager { max-width: 860px; }
.post .pager > span { flex: 1; }
@media (max-width: 640px) { .post { padding: 0 16px 32px; } .post-grid { grid-template-columns: 1fr; } }

/* ---------------------------------------------------------------- footer counter, feedback, admin */
.footer .visits { display: inline-flex; align-items: center; gap: 5px; margin-left: 10px; color: var(--faint); text-decoration: none; white-space: nowrap; }
.footer .visits[hidden] { display: none; }
.footer .visits svg { width: 14px; height: 14px; }
.footer .visits:hover { color: var(--accent); }
.footer .visits b { font-weight: 600; color: var(--muted); }
.fb-page h1, .admin-page h1 { font-size: clamp(40px, 5.4vw, 64px); margin: 14px 0 14px; }
.fb-form { max-width: 760px; margin-top: 28px; padding: 26px; display: grid; gap: 18px; box-shadow: none; }
.fb-form label { display: grid; gap: 6px; font-size: 14px; font-weight: 600; color: var(--ink); }
.fb-form label small { font-weight: 400; color: var(--faint); }
.fb-form .req { color: #DC2626; }
.fb-form input, .fb-form textarea { font: 400 15px var(--sans); color: var(--ink); background: var(--bg); border: 1px solid var(--line); border-radius: 10px; padding: 11px 13px; width: 100%; box-sizing: border-box; }
.fb-form textarea { resize: vertical; min-height: 140px; line-height: 1.6; }
.fb-form input:focus, .fb-form textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
.fb-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.fb-form .hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.fb-actions { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.fb-status { margin: 0; font-size: 14px; color: var(--muted); }
.fb-status.ok { color: #15803D; }
.fb-status.err { color: #DC2626; }
.fb-note { margin: 0; font-size: 12.5px; color: var(--faint); }
.adm-tabs { display: flex; gap: 8px; margin: 26px 0 22px; flex-wrap: wrap; }
.adm-tabs button { font: 500 14px var(--sans); border: 1px solid var(--line); background: var(--card); color: var(--muted); padding: 8px 16px; border-radius: 999px; cursor: pointer; }
.adm-tabs button[aria-selected="true"] { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.adm-badge { display: inline-block; min-width: 18px; margin-left: 4px; padding: 0 6px; border-radius: 999px; background: var(--accent); color: #fff; font-size: 12px; }
.adm-badge:empty { display: none; }
.adm-panel[hidden] { display: none; }
.adm-kpis { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.adm-kpis .card { padding: 18px 20px; box-shadow: none; }
.adm-kpis span { display: block; font-size: 12.5px; color: var(--faint); text-transform: uppercase; letter-spacing: .06em; }
.adm-kpis b { display: block; font: 400 38px var(--display); color: var(--ink); margin-top: 4px; }
.adm-updated { font-size: 13px; color: var(--faint); margin: 12px 0 20px; }
.adm-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.adm-grid .card { padding: 18px 20px; box-shadow: none; }
.adm-grid h3 { font-size: 15px; margin: 0 0 10px; }
.adm-grid ol { margin: 0; padding-left: 20px; font-size: 14px; }
.adm-grid li { display: flex; justify-content: space-between; gap: 12px; padding: 5px 0; border-top: 1px solid var(--line-2); }
.adm-grid li:first-child { border-top: 0; }
.adm-grid li span { overflow-wrap: anywhere; color: var(--ink-2); }
.adm-grid li b { font-weight: 500; color: var(--muted); white-space: nowrap; font-size: 13px; }
.adm-grid li.muted { color: var(--faint); }
.adm-report { width: 100%; height: 80vh; border: 1px solid var(--line); border-radius: 12px; background: #fff; }
.adm-fb { display: grid; gap: 14px; }
.fb-item { padding: 18px 20px; box-shadow: none; position: relative; }
.fb-head { display: flex; gap: 14px; flex-wrap: wrap; align-items: baseline; font-size: 14px; padding-right: 80px; }
.fb-head a { color: var(--accent); }
.fb-head time { color: var(--faint); font-size: 13px; }
.fb-msg { white-space: pre-wrap; margin: 10px 0 8px; color: var(--ink-2); line-height: 1.6; }
.fb-meta { color: var(--faint); font-size: 12.5px; overflow-wrap: anywhere; }
.fb-del { position: absolute; top: 14px; right: 16px; font: 500 13px var(--sans); color: #DC2626; background: none; border: 1px solid var(--line); border-radius: 8px; padding: 4px 10px; cursor: pointer; }
@media (max-width: 760px) { .adm-kpis, .adm-grid, .fb-row { grid-template-columns: 1fr 1fr; } .adm-grid, .fb-row { grid-template-columns: 1fr; } }
.fb-form .lbl { display: block; }

/* ---------------------------------------------------------------- photo hero + coloured icons */
.brand-img { width: 32px; height: 32px; border-radius: 50%; object-fit: cover; border: 2px solid var(--card); box-shadow: 0 0 0 1px var(--line); }
.hero .wrap { grid-template-columns: 1.1fr 1fr; gap: 48px; }
.portrait { position: relative; margin: 0; }
.portrait img { display: block; width: 100%; height: min(640px, 76vh); object-fit: cover; object-position: 50% 22%; border-radius: 28px;
  -webkit-mask-image: linear-gradient(to right, transparent 0, #000 22%); mask-image: linear-gradient(to right, transparent 0, #000 22%); }
.motto { position: absolute; top: 28px; right: 30px; margin: 0; display: grid; gap: 2px; text-align: left;
  font: 600 30px/1.05 "Caveat", cursive; color: #fff; text-shadow: 0 2px 14px rgba(0,0,0,.45); transform: rotate(-4deg); }
.motto i { display: block; width: 78px; height: 4px; margin-top: 6px; border-radius: 4px; background: linear-gradient(90deg, #3B82F6, #60A5FA); transform: rotate(-6deg); }
.hero-facts { position: absolute; right: -18px; bottom: 34px; list-style: none; margin: 0; padding: 14px 16px; display: grid; gap: 10px; min-width: 230px; max-width: 270px;
  background: color-mix(in srgb, var(--card) 80%, transparent); -webkit-backdrop-filter: blur(14px) saturate(1.3); backdrop-filter: blur(14px) saturate(1.3);
  border: 1px solid color-mix(in srgb, var(--line) 70%, transparent); border-radius: 18px; box-shadow: var(--shadow-lg);
  animation: float 7s ease-in-out infinite; animation-delay: 1.4s; }
.hero-facts li { display: flex; align-items: center; gap: 11px; font-size: 13.5px; line-height: 1.35; color: var(--ink-2); }
.hero-facts .icon { width: 30px; height: 30px; border-radius: 9px; }
.hero-facts .icon svg { width: 16px; height: 16px; }
.stats-strip { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin-top: 44px; }
.hero-stat { display: flex; align-items: center; gap: 14px; padding: 16px 18px; background: var(--card); border: 1px solid var(--line); border-radius: 18px; }
.hero-stat p { margin: 0; }
.hero-stat b { display: block; font: 400 32px/1 var(--display); color: var(--ink); }
.hero-stat span { display: block; font-size: 13px; color: var(--muted); margin-top: 4px; }
.area .icon.mark[data-c] { width: 48px; height: 48px; min-width: 0; padding: 0; border-radius: 14px; background: var(--cs); color: var(--cc); }
.area .icon.mark svg { width: 24px; height: 24px; }
.area[data-c]:hover { border-color: color-mix(in srgb, var(--cc) 45%, var(--line)); }
.area[data-c]::before { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 3px; background: var(--cc); opacity: 0; transition: opacity .25s; }
.area[data-c] { position: relative; overflow: hidden; }
.area[data-c]:hover::before { opacity: 1; }
.principles div:has(> .icon)::before { display: none; }
.principles div > .icon { grid-row: span 2; margin-top: 4px; }
.skills h3 { display: flex; align-items: center; gap: 10px; }
.skills h3 .icon { width: 30px; height: 30px; border-radius: 9px; }
.skills h3 .icon svg { width: 16px; height: 16px; }
.contact .mail { display: inline-flex; align-items: center; gap: 12px; }
.contact .mail .icon { width: 36px; height: 36px; border-radius: 10px; background: rgba(255,255,255,.1); color: #FCA5A5; }
@media (max-width: 960px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .portrait { max-width: 560px; }
  .portrait img { height: 480px; -webkit-mask-image: none; mask-image: none; }
  .hero-facts { right: 12px; bottom: 16px; }
  .stats-strip { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 520px) {
  .portrait img { height: 400px; border-radius: 20px; }
  .motto { font-size: 24px; top: 18px; right: 18px; }
  .hero-facts { position: static; margin-top: -40px; margin-left: 12px; margin-right: 12px; max-width: none; animation: none; }
  .hero-stat { padding: 12px 14px; gap: 10px; }
  .hero-stat b { font-size: 26px; }
}
/* a tile carries its own colour (not only when a parent has data-c) */
.icon[data-c] { background: var(--cs); color: var(--cc); }
.hero-facts { grid-template-columns: 1fr; }
/* solid, gradient tiles with white icons for the big items (work areas, stats, principles) */
.icon.solid[data-c], .area .icon.mark[data-c] { background: linear-gradient(140deg, color-mix(in srgb, var(--c) 82%, #fff), var(--c) 55%, color-mix(in srgb, var(--c) 78%, #000));
  color: #fff; box-shadow: 0 6px 16px -6px color-mix(in srgb, var(--c) 70%, transparent); }
.icon.solid svg, .area .icon.mark svg { stroke-width: 2; }
.hero .wrap.stats-wrap { display: block; }

/* compact hero: headline, photo and stats fit the first screen */
.hero { padding: 40px 0 28px; }
.hero h1 { font-size: clamp(40px, 5vw, 68px); line-height: 1.02; margin: 18px 0 18px; }
.hero .lead { font-size: 17px; line-height: 1.6; }
.hero-cta { margin-top: 26px; }
.hero-chips { margin-top: 20px; }
.portrait img { height: min(540px, 66vh); }
.stats-strip { margin-top: 30px; }
.hero-stat { padding: 12px 16px; }
.hero-stat b { font-size: 28px; }
.hero .scroll-cue { margin-top: 18px; }
/* tighter portrait + smaller facts card */
.hero .wrap { grid-template-columns: 1.35fr 1fr; gap: 40px; }
.portrait { max-width: 440px; justify-self: end; }
.portrait img { height: min(450px, 58vh); }
.motto { font-size: 24px; top: 20px; right: 22px; }
.motto i { width: 60px; height: 3px; }
.hero-facts { right: -14px; bottom: 22px; padding: 10px 12px; gap: 7px; min-width: 200px; max-width: 220px; border-radius: 14px; }
.hero-facts li { font-size: 12px; gap: 9px; }
.hero-facts .icon { width: 24px; height: 24px; border-radius: 7px; }
.hero-facts .icon svg { width: 13px; height: 13px; }
@media (max-width: 960px) { .portrait { max-width: 420px; justify-self: start; } .portrait img { height: 400px; } }
@media (max-width: 960px) { .hero .wrap { grid-template-columns: 1fr; } .portrait { justify-self: start; width: 100%; } }
@media (max-width: 520px) { .portrait { max-width: none; } .portrait img { height: 360px; } .hero-facts { max-width: none; min-width: 0; } }

/* ---------------------------------------------------------------- quiet scrollbars */
/* Page: thin and faint. Side panels (lesson list, all courses): invisible until you hover the panel. */
html { scrollbar-width: thin; scrollbar-color: color-mix(in srgb, var(--ink) 14%, transparent) transparent; }
.side, .courses-panel, .ss-drop { scrollbar-width: thin; scrollbar-color: transparent transparent; transition: scrollbar-color .3s; }
.side:hover, .courses-panel:hover, .ss-drop:hover { scrollbar-color: color-mix(in srgb, var(--ink) 16%, transparent) transparent; }
/* older WebKit (Safari) */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: color-mix(in srgb, var(--ink) 14%, transparent); border-radius: 8px; border: 2px solid transparent; background-clip: padding-box; }
.side::-webkit-scrollbar-thumb, .courses-panel::-webkit-scrollbar-thumb { background: transparent; }
.side:hover::-webkit-scrollbar-thumb, .courses-panel:hover::-webkit-scrollbar-thumb { background: color-mix(in srgb, var(--ink) 16%, transparent); background-clip: padding-box; }

/* ---------------------------------------------------------------- home: gradient theme (teal → blue → violet) */
:root { --g1: #0F766E; --g2: #2563EB; --g3: #7C3AED; --g4: #DB2777;
  --grad: linear-gradient(100deg, var(--g1), var(--g2) 55%, var(--g3));
  --mesh-a: rgba(20, 184, 166, .16); --mesh-b: rgba(37, 99, 235, .13); --mesh-c: rgba(124, 58, 237, .12); --mesh-d: rgba(219, 39, 119, .07); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --g1: #2DD4BF; --g2: #60A5FA; --g3: #A78BFA; --g4: #F472B6;
  --mesh-a: rgba(45, 212, 191, .10); --mesh-b: rgba(96, 165, 250, .10); --mesh-c: rgba(167, 139, 250, .10); --mesh-d: rgba(244, 114, 182, .05); } }
:root[data-theme="dark"] { --g1: #2DD4BF; --g2: #60A5FA; --g3: #A78BFA; --g4: #F472B6;
  --mesh-a: rgba(45, 212, 191, .10); --mesh-b: rgba(96, 165, 250, .10); --mesh-c: rgba(167, 139, 250, .10); --mesh-d: rgba(244, 114, 182, .05); }

/* soft colour mesh behind the whole page */
.page-home { background-color: var(--bg);
  background-image: radial-gradient(900px 600px at 8% -5%, var(--mesh-a), transparent 60%),
                    radial-gradient(800px 560px at 92% 4%, var(--mesh-b), transparent 60%),
                    radial-gradient(900px 700px at 70% 55%, var(--mesh-c), transparent 60%),
                    radial-gradient(700px 600px at 5% 80%, var(--mesh-d), transparent 60%);
  background-repeat: no-repeat; }
.page-home .hero::after { background: radial-gradient(circle, color-mix(in srgb, var(--g2) 18%, transparent), transparent 65%); }
.page-home .nav { background: color-mix(in srgb, var(--bg) 72%, transparent); }

/* gradient text accents */
.page-home h1 em, .page-home h2 em { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; padding-right: .06em; }
.page-home .eyebrow { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.page-home .eyebrow::before { background: var(--grad); }
.page-home .brand span { background: linear-gradient(100deg, var(--ink) 30%, var(--g2)); -webkit-background-clip: text; background-clip: text; color: transparent; }

/* buttons, pills, stats */
.page-home .btn-primary { background: var(--grad); border-color: transparent; color: #fff; background-size: 160% 100%; transition: background-position .5s, transform .2s, box-shadow .2s;
  box-shadow: 0 10px 24px -12px color-mix(in srgb, var(--g2) 70%, transparent); }
.page-home .btn-primary:hover { background-position: 100% 0; }
.page-home .status b { background: var(--grad); }
.page-home .hero-stat { background: linear-gradient(var(--card), var(--card)) padding-box, linear-gradient(120deg, color-mix(in srgb, var(--g1) 45%, var(--line)), var(--line) 40%, color-mix(in srgb, var(--g3) 45%, var(--line))) border-box; border: 1px solid transparent; }
.page-home .progress { background: var(--grad); }
.page-home .nav-links .pill { background: var(--grad); border-color: transparent; color: #fff; }

/* contact banner: deep gradient */
.page-home .contact { background: linear-gradient(125deg, #0B1B3A 0%, #1E2A78 45%, #4C1D95 80%, #0F766E 130%); border: 0; }
.page-home .contact::after { background: radial-gradient(circle, rgba(45, 212, 191, .35), transparent 65%); }
/* buttons keep the deep gradient in both themes so white text stays readable */
.page-home .btn-primary, .page-home .nav-links .pill { background-image: linear-gradient(100deg, #0F766E, #2563EB 55%, #7C3AED); background-size: 160% 100%; }

/* ---------------------------------------------------------------- calmer hero: smaller type + profile card */
.hero h1 { font-size: clamp(34px, 3.9vw, 54px); line-height: 1.05; margin: 16px 0 16px; max-width: 640px; }
.hero .lead { font-size: 16px; line-height: 1.65; max-width: 560px; }
.hero .wrap:has(.pcard) { grid-template-columns: 1.4fr 1fr; align-items: center; }
.pcard { padding: 26px 26px 22px; max-width: 400px; justify-self: end; width: 100%; box-shadow: var(--shadow-lg); }
.pc-who { display: flex; align-items: center; gap: 16px; padding-bottom: 18px; border-bottom: 1px solid var(--line); }
.pc-who img, .pc-who i { width: 84px; height: 84px; border-radius: 50%; object-fit: cover; flex: none;
  box-shadow: 0 0 0 3px var(--card), 0 0 0 5px color-mix(in srgb, var(--g2, var(--accent)) 35%, transparent); }
.pc-who i { display: grid; place-items: center; background: var(--ink); color: var(--bg); font: 400 30px var(--display); font-style: normal; }
.pc-who b { display: block; font-size: 17px; font-weight: 600; color: var(--ink); }
.pc-who span { display: block; font-size: 13.5px; color: var(--muted); line-height: 1.45; margin-top: 3px; }
.pc-facts { list-style: none; margin: 16px 0 0; padding: 0; display: grid; gap: 11px; }
.pc-facts li { display: flex; align-items: center; gap: 11px; font-size: 13.5px; color: var(--ink-2); line-height: 1.35; }
.pc-facts .icon { width: 30px; height: 30px; border-radius: 9px; }
.pc-facts .icon svg { width: 16px; height: 16px; }
@media (max-width: 960px) { .hero .wrap:has(.pcard) { grid-template-columns: 1fr; } .pcard { justify-self: start; max-width: 460px; } }

/* ---------------------------------------------------------------- phones: Learning Hub toolbar */
/* The sticky toolbar (search + 10 area buttons) took half the screen on phones and sat on top of the course
   cards, so taps hit the buttons instead of the cards. On small screens it scrolls away and the buttons form one
   swipeable row. */
@media (max-width: 760px) {
  .toolbar { position: static; padding: 12px 0; }
  .toolbar .wrap { flex-wrap: nowrap; flex-direction: column; align-items: stretch; gap: 10px; }
  .filters { flex-wrap: nowrap; overflow-x: auto; -webkit-overflow-scrolling: touch; scrollbar-width: none; margin: 0 -16px; padding: 2px 16px; }
  .filters::-webkit-scrollbar { display: none; }
  .filters button { flex: none; white-space: nowrap; padding: 7px 13px; font-size: 13px; }
}
@media (max-width: 760px) { .toolbar .wrap > * { flex: none; width: 100%; } }