/* Layout: "Redline" — engineering-pad grid ground, black rules, condensed caps headlines with highlighter marks, red markup accents; vertical (9:16) video frames. */
:root {
  --ink: #15171A;        /* dark panels */
  --paper: #ECEEE6;      /* engineering pad */
  --surface: #F7F8F3;
  --fg: #15171A;
  --muted: #5D625E;
  --line: #C9CFC3;
  --teal: #C8321C;       /* accent: redline (token name kept for compatibility) */
  --teal-soft: #F3EAA9;  /* highlighter wash */
  --amber: #C8321C;
  --hi: #F2DD3D;         /* highlighter */
  --grid: rgba(94,140,121,.11);
  --on-ink: #ECEEE6;
  --on-ink-muted: #A7ADA4;
  --video: #15171A;
  --on-accent: #FFFFFF;
  --font-display: "Archivo", "Arial Narrow", system-ui, sans-serif;
  --font-body: "Work Sans", "Segoe UI", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
  --max: 68rem;
}
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) {
  --ink: #0E0F10; --paper: #17191B; --surface: #1F2225; --fg: #ECEEE6; --muted: #A3A9A0; --line: #363C38;
  --teal: #FF6A4D; --teal-soft: #3A3517; --amber: #FF6A4D; --hi: #8A7A12; --grid: rgba(170,210,190,.06);
  --on-ink: #ECEEE6; --on-ink-muted: #9AA097; --video: #0E0F10; --on-accent: #15171A; color-scheme: dark; } }
:root[data-theme="dark"] {
  --ink: #0E0F10; --paper: #17191B; --surface: #1F2225; --fg: #ECEEE6; --muted: #A3A9A0; --line: #363C38;
  --teal: #FF6A4D; --teal-soft: #3A3517; --amber: #FF6A4D; --hi: #8A7A12; --grid: rgba(170,210,190,.06);
  --on-ink: #ECEEE6; --on-ink-muted: #9AA097; --video: #0E0F10; --on-accent: #15171A; color-scheme: dark; }

* { box-sizing: border-box; }
body { background: var(--paper); color: var(--fg); font-family: var(--font-body); font-size: 1.0625rem; line-height: 1.6; }
body::before { content: ""; position: fixed; inset: 0 0 auto; height: env(safe-area-inset-top, 0px); z-index: 10; background: var(--ink); }
.wrap { max-width: var(--max); margin: 0 auto; padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px)); }
.narrow { max-width: 44rem; }
h1, h2, h3 { font-family: var(--font-display); text-wrap: balance; margin: 0; line-height: 1.12; letter-spacing: -0.01em; }
a { color: var(--teal); }
:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; border-radius: 4px; }
.mono { font-family: var(--font-mono); font-size: .75rem; letter-spacing: .08em; text-transform: uppercase; }


header.site { background: var(--ink); color: var(--on-ink); position: sticky; top: env(safe-area-inset-top, 0px); z-index: 5; }
header.site .wrap { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding-block: .85rem; }
.brand { display: flex; align-items: baseline; gap: .6rem; color: var(--on-ink); text-decoration: none; }
.brand b { font-family: var(--font-display); font-size: 1.25rem; letter-spacing: .14em; font-weight: 700; }
.brand span { color: var(--on-ink-muted); font-size: .8rem; }
.hnav { display: flex; gap: .75rem; align-items: center; }
.lang { color: var(--on-ink); background: none; border: 1px solid #ffffff40; border-radius: 99px; padding: .3rem .8rem; font: inherit; font-size: .85rem; cursor: pointer; }
.btn { display: inline-flex; align-items: center; gap: .5rem; background: var(--teal); color: var(--on-accent); border: 0; border-radius: 6px; padding: .7rem 1.1rem; font: 600 .95rem var(--font-body); text-decoration: none; cursor: pointer; }
.btn:hover { filter: brightness(1.08); }
.hnav .btn { padding: .45rem .9rem; font-size: .85rem; }
@media (max-width: 560px) { .brand span, .hnav .btn { display: none; } }

/* hero */
.hero { background: var(--ink); color: var(--on-ink); padding-bottom: 0; }
.hero .wrap { padding-block: 2.5rem 0; display: grid; gap: 2rem; grid-template-columns: 1fr; }
@media (min-width: 900px) { .hero .wrap { grid-template-columns: 5fr 6fr; align-items: end; } }
.hero .eyebrow { color: var(--on-ink-muted); }
.hero h1 { font-size: clamp(2rem, 4.4vw, 3.1rem); font-weight: 700; margin-top: .75rem; color: #fff; }
.hero-copy { padding-bottom: 2.5rem; min-width: 0; }
.video { position: relative; aspect-ratio: 16 / 9; max-width: 100%; background: var(--video); border-radius: 10px 10px 0 0; overflow: hidden; display: grid; place-items: center; color: var(--on-ink); border: 1px solid #ffffff1a; border-bottom: 0; }
.video.inline { border-radius: 10px; border: 1px solid var(--line); margin-block: 1.75rem; }
.video canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.video .play { position: relative; display: grid; justify-items: center; gap: .6rem; text-align: center; padding: 1rem; }
.video .disc { width: 4.2rem; height: 4.2rem; border-radius: 50%; background: var(--teal); display: grid; place-items: center; }
.video .disc::after { content: ""; border-left: 1.1rem solid #fff; border-top: .7rem solid transparent; border-bottom: .7rem solid transparent; margin-left: .3rem; }
.video .vl { font-family: var(--font-mono); font-size: .72rem; letter-spacing: .08em; text-transform: uppercase; color: var(--on-ink-muted); }
.video .face { position: absolute; left: 1rem; bottom: .9rem; font-size: .8rem; color: var(--on-ink-muted); }
details.script { margin-top: .9rem; }
details.script summary { cursor: pointer; font-weight: 600; color: var(--teal); font-size: .95rem; }
details.script div { margin-top: .6rem; padding: 1rem 1.2rem; background: var(--surface); border: 1px solid var(--line); border-radius: 8px; font-size: .95rem; color: var(--fg); }
details.script p { margin: 0 0 .55rem; }

/* doors */
.doors { padding-block: 2.75rem 1rem; }
.doors .lead { font-family: var(--font-display); font-size: clamp(1.3rem, 2.4vw, 1.65rem); font-weight: 500; margin: 0 0 1.25rem; max-width: 40rem; text-wrap: balance; }
.door-list { display: grid; gap: .75rem; }
.door { display: grid; grid-template-columns: auto 1fr auto; gap: 1.1rem; align-items: center; text-align: left; width: 100%; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 1.2rem 1.3rem; cursor: pointer; color: var(--fg); font: inherit; transition: border-color .15s, transform .15s; }
.door:hover { border-color: var(--teal); transform: translateX(3px); }
.door .n { font-family: var(--font-display); font-weight: 700; font-size: 1.6rem; color: var(--teal); width: 2rem; }
.door .txt { min-width: 0; }
.door strong { display: block; font-family: var(--font-display); font-size: clamp(1.1rem, 2vw, 1.3rem); font-weight: 700; color: var(--ink); line-height: 1.25; }
:root[data-theme="dark"] .door strong { color: var(--fg); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .door strong { color: var(--fg); } }
.door span { color: var(--muted); font-size: .95rem; }
.door .arrow { font-size: 1.4rem; color: var(--teal); }

/* about */
.about { padding-block: 2.5rem 3rem; display: grid; gap: 2rem; }
@media (min-width: 860px) { .about { grid-template-columns: 6fr 5fr; align-items: start; } }
.about p { margin: .6rem 0 0; color: var(--fg); }
.about h2 { font-size: 1.4rem; }
.proof { display: grid; gap: .6rem; margin: 0; padding: 0; list-style: none; }
.proof li { display: grid; grid-template-columns: 8.5rem 1fr; gap: .9rem; align-items: baseline; border-top: 1px solid var(--line); padding-top: .6rem; }
.proof b { font-family: var(--font-display); font-size: 1.35rem; color: var(--amber); font-variant-numeric: tabular-nums; }
.proof span { color: var(--muted); font-size: .95rem; }

/* problem page */
.crumb { padding-block: 1.5rem 0; }
.crumb button { background: none; border: 0; color: var(--teal); font: 500 .95rem var(--font-body); cursor: pointer; padding: 0; }
.ptitle { padding-block: 1rem 0; }
.ptitle h1 { font-size: clamp(1.75rem, 3.6vw, 2.5rem); color: var(--ink); font-weight: 700; }
:root[data-theme="dark"] .ptitle h1, :root[data-theme="dark"] .sec h2 { color: var(--fg); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .ptitle h1, :root:not([data-theme="light"]) .sec h2 { color: var(--fg); } }
.sec { margin-top: 2.2rem; }
.sec h2 { font-size: 1.35rem; color: var(--ink); margin-bottom: .6rem; }
.sec p { margin: 0 0 .9rem; }
.callout { background: var(--teal-soft); border-radius: 10px; padding: 1.3rem 1.4rem; }
.callout .mono { color: var(--teal); }
.callout p { margin: .4rem 0 0; font-size: 1.08rem; }
ol.think { list-style: none; padding: 0; margin: 0; display: grid; gap: 1rem; counter-reset: k; }
ol.think li { counter-increment: k; display: grid; grid-template-columns: 2.2rem 1fr; gap: .8rem; }
ol.think li::before { content: counter(k); font-family: var(--font-display); font-weight: 700; font-size: 1.25rem; color: var(--on-accent); background: var(--teal); width: 2.2rem; height: 2.2rem; border-radius: 50%; display: grid; place-items: center; }
ol.think strong { display: block; color: var(--fg); }
ol.think span { color: var(--muted); }

.close { margin-top: 2.75rem; display: grid; gap: 1rem; }
@media (min-width: 760px) { .close { grid-template-columns: 1fr 1fr; } }
.close > div { border-radius: 12px; padding: 1.5rem; min-width: 0; }
.talk { background: var(--ink); color: var(--on-ink); }
.talk h3, .mag h3 { font-size: 1.25rem; margin: .4rem 0 .6rem; }
.talk h3 { color: #fff; }
.talk p { margin: 0 0 1rem; color: var(--on-ink); }
.talk .mono { color: var(--on-ink-muted); }
.talk small { display: block; margin-top: .9rem; color: var(--on-ink-muted); user-select: all; }
.mag { background: var(--surface); border: 2px solid var(--teal); }
.mag .mono { color: var(--teal); }
.mag p { margin: 0 0 1rem; color: var(--muted); }
.mag form { display: flex; gap: .5rem; flex-wrap: wrap; }
.mag input { flex: 1 1 12rem; min-width: 0; font: inherit; padding: .65rem .8rem; border: 1px solid var(--line); border-radius: 6px; background: var(--paper); color: var(--fg); }
.mag .note { font-size: .8rem; margin: .6rem 0 0; }
.mag .ok { margin-top: .8rem; padding: .7rem .9rem; border-radius: 6px; background: var(--teal-soft); font-size: .9rem; color: var(--fg); }

.others { margin-top: 2.75rem; padding-bottom: 3rem; }
.others h2 { font-size: 1.1rem; margin-bottom: .8rem; }

.blog-grid { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fill, minmax(min(100%, 19rem), 1fr)); }
.post-card { display: grid; gap: .45rem; align-content: start; text-align: left; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 1.2rem 1.25rem; cursor: pointer; color: var(--fg); font: inherit; transition: border-color .15s; }
.post-card:hover { border-color: var(--teal); }
.post-card .mono { color: var(--teal); }
.post-card strong { font-family: var(--font-display); font-size: 1.15rem; line-height: 1.25; color: var(--fg); text-wrap: balance; }
.post-card span.d { color: var(--muted); font-size: .93rem; }
.blogsec { padding-block: 1rem 3rem; }
.blogsec h2, .others h2 { font-size: 1.35rem; margin-bottom: 1rem; }
.post-list { display: grid; gap: .6rem; }
.post-link { display: block; text-align: left; width: 100%; background: none; border: 0; border-top: 1px solid var(--line); padding: .8rem 0 .2rem; cursor: pointer; font: 600 1.02rem var(--font-body); color: var(--teal); }
.article h1 { font-size: clamp(1.75rem, 3.6vw, 2.5rem); font-weight: 700; margin-top: .75rem; }
.article .dek { font-size: 1.18rem; color: var(--muted); margin: 1rem 0 1.5rem; }
.article .meta { color: var(--muted); font-size: .85rem; display: flex; gap: .5rem 1rem; flex-wrap: wrap; border-block: 1px solid var(--line); padding-block: .6rem; }
.article h2 { font-size: 1.3rem; margin: 2rem 0 .6rem; }
.article p { margin: 0 0 1rem; }
.article ul { margin: 0 0 1rem; padding-left: 1.2rem; display: grid; gap: .4rem; }
.article ul li::marker { color: var(--teal); }
.post-cta { margin-top: 2.5rem; background: var(--teal-soft); border-radius: 12px; padding: 1.5rem; display: grid; gap: .8rem; }
.post-cta .mono { color: var(--teal); }
.post-cta h3 { font-size: 1.25rem; }
.post-cta p { margin: 0; }
.post-cta .row { display: flex; gap: .6rem; flex-wrap: wrap; }
.btn.ghost { background: transparent; color: var(--teal); border: 1px solid var(--teal); }
.hnav .navlink { color: var(--on-ink); background: none; border: 0; font: 500 .9rem var(--font-body); cursor: pointer; padding: .3rem .2rem; }
footer { border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem; }
footer .wrap { padding-block: 1.5rem; display: flex; flex-wrap: wrap; gap: .5rem 1.5rem; justify-content: space-between; }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }

/* ===== Redline layer ===== */
body { background-color: var(--paper); background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px); background-size: 36px 36px; }
body::before { background: var(--paper); }
h1, h2, h3 { font-stretch: 80%; font-weight: 800; letter-spacing: -.005em; }
a { color: var(--teal); }
mark { background: linear-gradient(transparent 6%, var(--hi) 6%, var(--hi) 94%, transparent 94%); color: inherit; padding: 0 .06em; -webkit-box-decoration-break: clone; box-decoration-break: clone; }
header.site { background: var(--paper); color: var(--fg); border-bottom: 3px solid var(--fg); }
.brand { color: var(--fg); }
.brand b { font-family: var(--font-display); font-stretch: 75%; font-weight: 900; letter-spacing: .1em; font-size: 1.4rem; }
.brand span { color: var(--teal); font-family: var(--font-mono); font-size: .72rem; text-transform: uppercase; letter-spacing: .12em; }
.hnav .navlink, .hnav a.navlink { color: var(--fg); }
.lang, a.lang { color: var(--fg); border: 2px solid var(--fg); border-radius: 0; }
.btn { border-radius: 2px; }
.btn.ghost { border-width: 2px; }
.hero { background: transparent; color: var(--fg); border-bottom: 3px solid var(--fg); }
.hero .wrap { padding-block: 3rem; align-items: center; }
@media (min-width: 900px) { .hero .wrap { grid-template-columns: 1fr auto; } }
.hero .eyebrow { color: var(--teal); }
.hero h1 { color: var(--fg); text-transform: uppercase; font-size: clamp(2.5rem, 6.4vw, 4.6rem); line-height: .96; font-stretch: 72%; font-weight: 900; }
.hero-copy { padding-bottom: 0; }
.video { aspect-ratio: 9 / 16; width: min(100%, 19rem); border-radius: 0; border: 3px solid var(--fg); background: var(--video); justify-self: center; }
.video.inline { border: 3px solid var(--fg); border-radius: 0; margin-inline: auto; width: min(100%, 18rem); }
.video .disc { background: var(--teal); }
.video .face { color: var(--on-ink-muted); font-family: var(--font-mono); font-size: .7rem; text-transform: uppercase; letter-spacing: .08em; }
details.script div { border-radius: 0; border: 2px solid var(--fg); }
.doors .lead { font-family: var(--font-body); font-weight: 500; }
.door { border: 2px solid var(--fg); border-radius: 0; background: var(--surface); transition: box-shadow .15s, background .15s; }
.door:hover { transform: none; background: var(--teal-soft); box-shadow: 6px 6px 0 var(--fg); border-color: var(--fg); }
.door .n { color: var(--teal); font-stretch: 75%; font-weight: 900; font-size: 2rem; }
.door strong { font-stretch: 85%; }
.post-card { border: 2px solid var(--fg); border-radius: 0; background: var(--surface); transition: box-shadow .15s; }
.post-card:hover { border-color: var(--fg); box-shadow: 6px 6px 0 var(--fg); }
.post-card strong { font-stretch: 85%; }
.proof li { border-top: 2px solid var(--fg); grid-template-columns: minmax(9rem, max-content) 1fr; }
.proof b { white-space: nowrap; }
.proof b { color: var(--teal); font-stretch: 72%; font-weight: 900; font-size: 1.7rem; }
.ptitle h1, .article h1 { font-stretch: 78%; font-weight: 900; line-height: 1.02; }
.sec h2 { font-stretch: 80%; }
.callout { background: var(--teal-soft); border-radius: 0; border-left: 6px solid var(--teal); }
ol.think li::before { border-radius: 0; background: transparent; color: var(--teal); border: 3px solid var(--fg); font-stretch: 75%; }
.close > div { border-radius: 0; }
.talk { background: var(--ink); color: var(--on-ink); border: 3px solid var(--fg); }
.mag { border: 6px double var(--teal); background: var(--surface); }
.mag input { border-radius: 0; border: 2px solid var(--fg); background: var(--paper); }
.mag .ok { border-radius: 0; }
.post-cta { border-radius: 0; border: 3px solid var(--fg); background: var(--teal-soft); }
.article .meta { border-block: 2px solid var(--fg); }
.post-link { color: var(--teal); }
footer { border-top: 3px solid var(--fg); }

/* static-site additions */
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; }
img { max-width: 100%; }
[hidden] { display: none !important; }
a.door, a.post-card { text-decoration: none; }
a.btn { text-decoration: none; }
.hnav a.navlink, .hnav a.lang { text-decoration: none; display: inline-block; }
.crumb a { color: var(--teal); text-decoration: none; font-weight: 500; }
a.post-link { text-decoration: none; display: block; }
.video iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 1rem; top: 1rem; z-index: 20; background: var(--surface); padding: .5rem 1rem; }