/* Shared structure. Themes (assets/themes/*.css) set the variables and the hero/tangle placement. */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--ground); color: var(--ink); font: 400 17px/1.6 var(--body); -webkit-font-smoothing: antialiased; }
a { color: inherit; }
p { margin: 0; }
em { font-style: italic; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 24px; }
.center { text-align: center; }
.mono { font-family: var(--mono); font-size: 13px; color: var(--accent); letter-spacing: .08em; }
.eyebrow { font: 500 12px/1 var(--mono); letter-spacing: .18em; text-transform: uppercase; color: var(--accent); margin: 0; }

/* nav */
.nav { position: fixed; inset: 0 0 auto 0; z-index: 10; display: flex; align-items: center; justify-content: space-between; padding: 16px 28px; transition: background .3s, box-shadow .3s; }
.nav.solid { background: rgba(var(--ground-rgb), .92); backdrop-filter: blur(8px); box-shadow: 0 1px 0 var(--rule); }
.nav nav { display: flex; align-items: center; gap: 28px; font-size: 15px; font-weight: 500; }
.nav nav a { text-decoration: none; }
.nav nav a:not(.btn):hover { color: var(--accent); }
.brand { font: var(--brand-font); letter-spacing: var(--brand-track, .01em); text-decoration: none; }
.brand em { color: var(--accent); font-weight: inherit; }

/* buttons */
.btn { display: inline-block; padding: 14px 26px; background: var(--btn-bg); color: var(--btn-fg); font: 500 15px/1 var(--body); text-decoration: none; border: 1px solid var(--btn-bg); border-radius: var(--radius, 2px); transition: background .2s, color .2s, transform .2s; }
.btn:hover { background: var(--accent); border-color: var(--accent); color: var(--btn-hover-fg, #fff); transform: translateY(-1px); }
.btn-sm { padding: 10px 16px; font-size: 14px; }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--ink); }
.btn-light { background: var(--cta-fg); color: var(--cta-bg); border-color: var(--cta-fg); }
.btn-light:hover { background: var(--accent); border-color: var(--accent); color: #fff; }
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 32px; }
.center .cta-row { justify-content: center; }

/* dither canvases: transparent, fill their host */
[data-dither] { position: absolute; inset: 0; width: 100%; height: 100%; opacity: 0; transition: opacity 1.2s ease; }
[data-dither].ready { opacity: 1; }
.hero, .tangle { position: relative; overflow: hidden; }
.scrim { position: absolute; inset: 0; pointer-events: none; }
.hero-copy, .tangle-copy { position: relative; z-index: 2; pointer-events: none; }
.hero-copy a, .tangle-copy a { pointer-events: auto; }
.lede { font-size: 19px; color: var(--ink-soft); max-width: 520px; margin: 24px 0 0; }
.caption { margin: 0; font: var(--caption-font); color: var(--ink-soft); }

/* sections */
.section { padding: 112px 0; }
.section.alt { background: var(--ground-2); border-block: 1px solid var(--rule); }
h1, h2, h3 { font-family: var(--display); font-weight: var(--display-weight, 600); margin: 0; }
h2 { font-size: clamp(36px, 5vw, 60px); line-height: 1.04; letter-spacing: var(--h-track, -.01em); margin-top: 14px; max-width: 780px; }
h2 em, h1 em { color: var(--accent); }
h3 { font-size: 24px; line-height: 1.15; margin-bottom: 8px; }
.grid { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 56px; border-top: 1px solid var(--rule); border-left: 1px solid var(--rule); }
.card { padding: 32px 28px 36px; border-right: 1px solid var(--rule); border-bottom: 1px solid var(--rule); transition: background .25s; }
.card:hover { background: var(--ground-2); }
.card .num { display: block; font: var(--num-font); color: var(--accent); margin-bottom: 28px; }
.card p, .steps p, .principles p { color: var(--ink-soft); font-size: 16px; }
.steps { list-style: none; padding: 0; margin: 56px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.steps li { border-top: 2px solid var(--ink); padding-top: 20px; }
.steps h3 { margin-top: 10px; font-size: 30px; }
.split { display: grid; grid-template-columns: 1fr 1.2fr; gap: 64px; align-items: start; }
.principles { list-style: none; padding: 0; margin: 0; }
.principles li { padding: 0 0 28px; margin-bottom: 28px; border-bottom: 1px solid var(--rule); }
.principles li:last-child { border: 0; margin: 0; padding: 0; }
.cta { background: var(--cta-bg); color: var(--cta-fg); }
.cta .lede { color: var(--cta-soft); margin-inline: auto; }
.cta h2 { margin-inline: auto; }
.cta .eyebrow { color: var(--cta-accent); }
.footer { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; padding: 28px; font-size: 14px; color: var(--ink-soft); border-top: 1px solid var(--rule); }
.footer .brand { font-size: 22px; color: var(--ink); }

.note { margin-top: 32px; max-width: 640px; color: var(--ink-soft); font-size: 16px; border-left: 3px solid var(--accent); padding-left: 16px; }
.about p { color: var(--ink-soft); margin-bottom: 16px; max-width: 60ch; }
.about .chips { margin-top: 0; }
.stack-group { margin-top: 18px; }
.stack-label { font: 500 11px/1 var(--mono); letter-spacing: .14em; text-transform: uppercase; color: var(--accent); margin: 0 0 10px; }
.stack-h { margin-top: 32px; font-size: 18px; }

/* capabilities */
.caps-lede { margin-top: 20px; }
.caps { list-style: none; padding: 0; margin: 48px 0 0; border-top: 1px solid var(--rule); }
.caps li { display: grid; grid-template-columns: 56px minmax(0, 1fr) minmax(0, 1.5fr); gap: 24px; align-items: baseline; padding: 28px 0; border-bottom: 1px solid var(--rule); }
.caps h3 { margin: 0; font-size: 24px; }
.caps p { color: var(--ink-soft); font-size: 16px; max-width: 60ch; }
@media (max-width: 860px) { .caps li { grid-template-columns: 40px minmax(0, 1fr); gap: 8px 16px; } .caps p { grid-column: 2; } }

/* tangle (second dither section) */
.tangle { min-height: 92vh; display: flex; align-items: center; }
.tangle-copy h2 { margin-top: 14px; }
.chips { list-style: none; padding: 0; margin: 28px 0 0; display: flex; flex-wrap: wrap; gap: 8px; }
.chips li { font: 500 12px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; padding: 9px 12px; border: 1px solid var(--rule); background: rgba(var(--ground-rgb), .7); }

/* variant switcher (comparison only) */
.vswitch { position: fixed; left: 50%; bottom: 14px; transform: translateX(-50%); z-index: 50; display: flex; gap: 4px; padding: 5px; background: #111; border-radius: 999px; font: 500 11px/1 ui-monospace, monospace; box-shadow: 0 6px 24px rgba(0,0,0,.3); }
.vswitch a { white-space: nowrap; color: #bbb; text-decoration: none; padding: 8px 12px; border-radius: 999px; }
.vswitch a.on { background: #fff; color: #111; }
.vswitch a:hover:not(.on) { color: #fff; }
@media (max-width: 760px) { .vswitch .n { display: none; } }

.reveal { opacity: 0; transform: translateY(16px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } html { scroll-behavior: auto; } }

@media (max-width: 860px) {
  .grid, .steps { grid-template-columns: 1fr; }
  .split { grid-template-columns: 1fr; gap: 32px; }
  .section { padding: 80px 0; }
}

/* language toggle */
.nav nav { gap: 22px; }
.lang { display: inline-flex; border: 1px solid var(--rule); border-radius: var(--radius, 2px); overflow: hidden; }
.lang button { font: 600 12px/1 var(--mono); letter-spacing: .08em; padding: 8px 10px; background: transparent; color: var(--ink); border: 0; cursor: pointer; transition: background .25s, color .25s; }
.lang button[aria-pressed="true"] { background: var(--ink); color: var(--ground); }
.lang button:hover:not([aria-pressed="true"]) { color: var(--accent); }
.lang button:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; }
.tr:not(.reveal) { transition: opacity .18s ease; }
html.swapping .tr { opacity: 0 !important; transition: opacity .18s ease !important; }

/* faq */
.faq-lede { margin-top: 20px; }
.faq details { border-bottom: 1px solid var(--rule); }
.faq details:first-child { border-top: 1px solid var(--rule); }
.faq summary { cursor: pointer; list-style: none; position: relative; padding: 20px 40px 20px 0; font: 600 20px/1.25 var(--display); font-weight: var(--display-weight, 600); color: var(--ink); }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; position: absolute; right: 6px; top: 18px; font: 400 26px/1 var(--mono); color: var(--accent); transition: transform .25s ease; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq summary:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.faq details p { color: var(--ink-soft); padding: 0 40px 22px 0; max-width: 60ch; }
.faq details[open] p { animation: faqin .3s ease; }
@keyframes faqin { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: none; } }

/* contact line, footer link, legal page */
.cta-mail { margin-top: 20px; font-size: 15px; color: var(--cta-soft); }
.cta-mail a { color: var(--cta-fg); text-underline-offset: 3px; }
.footer a { color: inherit; text-underline-offset: 3px; }
.legal { padding: 140px 0 96px; }
.legal .wrap { max-width: 720px; }
.legal h1 { font-size: clamp(40px, 6vw, 72px); line-height: 1; margin: 14px 0 16px; }
.legal-lede { font-size: 19px; color: var(--ink-soft); margin-bottom: 24px; }
.legal h2 { font-size: 24px; margin: 36px 0 8px; max-width: none; }
.legal p { color: var(--ink-soft); }
.legal a { color: var(--accent); }
.legal-date { margin-top: 40px; font: 12px var(--mono); }

@media (max-width: 1040px) { .nav nav a:not(.btn) { display: none; } .nav nav { gap: 14px; } }


/* figure note (hero art explainer) */
.fig-note { position: absolute; right: 28px; bottom: 20px; z-index: 3; font: var(--caption-font); color: var(--ink-soft); }
.fig-note summary { cursor: pointer; list-style: none; display: flex; align-items: center; gap: 12px; letter-spacing: .06em; text-transform: uppercase; }
.fig-note summary::-webkit-details-marker { display: none; }
.fig-note summary:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
.fig-note .why { color: var(--accent); border: 1px solid currentColor; padding: 5px 9px; transition: background .2s, color .2s; }
.fig-note summary:hover .why, .fig-note[open] .why { background: var(--accent); color: var(--btn-fg); }
.fig-body { position: absolute; right: 0; bottom: calc(100% + 12px); width: min(390px, calc(100vw - 40px)); padding: 18px 20px; background: rgba(var(--ground-rgb), .96); border: 1px solid var(--rule); backdrop-filter: blur(6px); font: 400 14px/1.55 var(--body); letter-spacing: 0; text-transform: none; color: var(--ink); animation: faqin .25s ease; }
.fig-body p + p { margin-top: 10px; color: var(--ink-soft); }
@media (max-width: 700px) { .fig-note { left: 20px; right: 20px; bottom: 14px; } .fig-note summary { flex-wrap: wrap; gap: 8px; } .fig-body { right: auto; left: 0; } }

/* language switch v2: sliding thumb, compact on phones */
.lang { position: relative; padding: 2px; border-radius: var(--radius, 2px); overflow: visible; }
.lang button { position: relative; z-index: 1; min-width: 38px; padding: 8px 10px; border-radius: calc(var(--radius, 2px) - 1px); }
@supports selector(:has(*)) {
  .lang::before { content: ''; position: absolute; top: 2px; bottom: 2px; left: 2px; width: calc(50% - 2px); background: var(--ink); border-radius: calc(var(--radius, 2px) - 1px); transition: transform .32s cubic-bezier(.5, 0, .2, 1); }
  .lang:has(button[data-lang="fr"][aria-pressed="true"])::before { transform: translateX(100%); }
  .lang button[aria-pressed="true"] { background: transparent; color: var(--ground); }
  .lang button { transition: color .25s; }
}

@media (max-width: 700px) {
  .nav { padding: 10px 14px; }
  .nav .brand { font-size: 17px; }
  .nav nav { gap: 10px; }
  .nav .btn-sm { padding: 9px 12px; font-size: 13px; white-space: nowrap; }
  .lang button { min-width: 32px; padding: 7px 7px; font-size: 11px; }
}