/* The bar across every page of subinternal.com, and its phone menu. Self-contained: its own colours, sizes and type, so
   it looks the same over the main pages and over the research posts, which have a stylesheet of their own. */
@font-face { font-family: "Geist"; src: url("/fonts/Geist-Variable.woff2") format("woff2"); font-weight: 100 900; font-display: swap; }
@font-face { font-family: "Geist Mono"; src: url("/fonts/GeistMono-Variable.woff2") format("woff2"); font-weight: 100 900; font-display: swap; }

.nav, .nav-panel {
  --n-ink: #141518;
  --n-ink-2: #4d4f56;
  --n-muted: #5f6168;
  --n-bg: #f2f1ee;
  --n-surface: #ffffff;
  --n-line: rgb(20 21 24 / 0.08);
  --n-line-2: rgb(20 21 24 / 0.14);
  --n-hover: rgb(20 21 24 / 0.05);
  --n-ease: cubic-bezier(0.22, 1, 0.36, 1);
  --n-sans: "Geist", ui-sans-serif, system-ui, sans-serif;
  --n-mono: "Geist Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

/* At the top of the page the bar is open: as wide as the page, larger, with nothing behind it. Once the page moves it
   draws in to a floating pill, a firm white surface with a soft shadow. One element, its width, height and surface easing
   between the two. */
.nav { position: fixed; top: 12px; left: 50%; z-index: 10; display: flex; align-items: center; justify-content: space-between; gap: 8px; width: min(1120px, calc(100% - 48px)); padding: 12px 0; border: 1px solid transparent; border-radius: 9999px; background: rgb(255 255 255 / 0); color: var(--n-ink); font: 400 15px/20px var(--n-sans); -webkit-font-smoothing: antialiased; transform: translateX(-50%); transition: width 600ms var(--n-ease), top 600ms var(--n-ease), padding 600ms var(--n-ease), background-color 500ms var(--n-ease), border-color 500ms var(--n-ease), box-shadow 500ms var(--n-ease), backdrop-filter 500ms var(--n-ease); }
.nav.scrolled { top: 16px; width: min(760px, calc(100% - 32px)); padding: 8px 8px 8px 20px; border-color: var(--n-line-2); background: rgb(255 255 255 / 0.86); box-shadow: 0 1px 2px rgb(20 21 24 / 0.04), 0 16px 40px -18px rgb(20 21 24 / 0.24); backdrop-filter: saturate(1.4) blur(16px); -webkit-backdrop-filter: saturate(1.4) blur(16px); }
.nav a { color: inherit; text-decoration: none; }
.nav .brand { display: inline-flex; align-items: center; gap: 10px; font: 500 17px/24px var(--n-mono); letter-spacing: -0.01em; transition: transform 600ms var(--n-ease); }
.nav.scrolled .brand { transform: scale(0.94); transform-origin: left center; }
.nav .brand svg { width: 28px; height: 28px; flex: none; }
.nav .brand rect { fill: var(--n-ink); }
.nav .brand path { fill: var(--n-bg); }

/* Each link is a quiet pill on hover; the page you are on is in full ink with a hairline under it. */
.nav .links { display: flex; align-items: center; gap: 2px; }
.nav .links > a, .nav .drop-btn { display: inline-flex; align-items: center; gap: 4px; height: 40px; padding: 0 14px; border: 0; border-radius: 9999px; background: transparent; color: var(--n-ink-2); font: 500 15px/20px var(--n-sans); cursor: pointer; transition: background-color 300ms var(--n-ease), color 300ms var(--n-ease); }
.nav .links > a:hover, .nav .drop-btn:hover, .nav .drop-btn[aria-expanded="true"] { background: var(--n-hover); color: var(--n-ink); }
.nav .links > a[aria-current="page"], .nav .drop-btn.current { color: var(--n-ink); }
.nav .links > a[aria-current="page"] { text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 6px; }
.nav .drop-btn svg { width: 12px; height: 12px; transition: transform 300ms var(--n-ease); }
.nav .drop-btn[aria-expanded="true"] svg { transform: rotate(180deg); }
.nav .cta { display: inline-flex; align-items: center; height: 40px; padding: 0 18px; border-radius: 9999px; background: var(--n-ink); color: var(--n-bg); font-weight: 600; white-space: nowrap; transition: transform 300ms var(--n-ease), opacity 300ms var(--n-ease); }
.nav .cta:hover { opacity: 0.88; transform: translateY(-1px); }
.nav :focus-visible { outline: 2px solid var(--n-ink); outline-offset: 2px; }

/* What we build: a panel under the bar with the six kinds of work and private AI beside them. */
.nav .drop { position: static; }
.nav .drop-panel { position: absolute; top: calc(100% + 10px); left: 50%; display: grid; grid-template-columns: minmax(0, 1fr) 232px; gap: 8px; width: 680px; padding: 8px; border: 1px solid var(--n-line-2); border-radius: 24px; background: var(--n-surface); box-shadow: 0 1px 2px rgb(20 21 24 / 0.04), 0 24px 48px -24px rgb(20 21 24 / 0.28); opacity: 0; transform: translate(-50%, -8px); transition: opacity 300ms var(--n-ease), transform 300ms var(--n-ease); }
.nav .drop-panel[hidden] { display: none; }
.nav .drop-panel.open { opacity: 1; transform: translate(-50%, 0); }
.nav .drop-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 2px; }
.nav .drop-grid a { display: grid; gap: 2px; padding: 12px 16px; border-radius: 16px; transition: background-color 300ms var(--n-ease); }
.nav .drop-grid a:hover, .nav .drop-grid a:focus-visible { background: var(--n-hover); }
.nav .drop-grid b { font-weight: 600; color: var(--n-ink); }
.nav .drop-grid span { color: var(--n-muted); font-size: 13px; line-height: 18px; }
/* Tools: a narrow panel of one column, its links leaving the site marked with an arrow out. */
.nav .drop-panel.small { grid-template-columns: minmax(0, 1fr); width: 360px; }
.nav .drop-grid.one { grid-template-columns: minmax(0, 1fr); }
.nav .drop-grid .out { width: 10px; height: 10px; margin-left: 4px; color: var(--n-muted); vertical-align: 0; }
.nav .drop-feature { display: grid; align-content: space-between; gap: 24px; padding: 16px; border-radius: 16px; background: var(--n-ink); color: var(--n-bg); }
.nav .drop-feature small { color: rgb(242 241 238 / 0.64); font: 500 12px/16px var(--n-mono); letter-spacing: 0.08em; text-transform: uppercase; }
.nav .drop-feature b { display: block; margin-top: 8px; font-size: 18px; line-height: 24px; font-weight: 600; letter-spacing: -0.01em; }
.nav .drop-feature > span:last-of-type { color: rgb(242 241 238 / 0.72); font-size: 13px; line-height: 18px; }
.nav .drop-feature b { color: var(--n-bg); }
.nav .drop-feature em { font-style: normal; font-weight: 600; }
.nav .drop-feature:hover em { text-decoration: underline; text-underline-offset: 4px; }

/* The phone menu: the bar's button, and a full height panel grouped as the bar is. */
.nav .menu { display: none; position: relative; width: 40px; height: 40px; padding: 0; border: 0; border-radius: 9999px; background: transparent; cursor: pointer; }
.nav .menu i { position: absolute; left: 12px; right: 12px; height: 1.5px; background: var(--n-ink); transition: transform 500ms var(--n-ease); }
.nav .menu i:first-child { transform: translateY(-3px); }
.nav .menu i:last-child { transform: translateY(3px); }
.nav .menu[aria-expanded="true"] i:first-child { transform: rotate(45deg); }
.nav .menu[aria-expanded="true"] i:last-child { transform: rotate(-45deg); }
.nav-panel { position: fixed; inset: 0; z-index: 9; display: grid; align-content: start; gap: 24px; overflow-y: auto; padding: 96px 24px 32px; background: rgb(242 241 238 / 0.96); color: var(--n-ink); font: 400 16px/24px var(--n-sans); backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px); }
.nav-panel[hidden] { display: none; }
.nav-panel a { color: inherit; text-decoration: none; }
.nav-panel > * { opacity: 0; transform: translateY(24px); transition: transform 500ms var(--n-ease), opacity 500ms var(--n-ease); }
.nav-panel.open > * { opacity: 1; transform: none; }
.nav-panel.open > :nth-child(2) { transition-delay: 60ms; }
.nav-panel.open > :nth-child(3) { transition-delay: 120ms; }
.nav-panel.open > :nth-child(4) { transition-delay: 180ms; }
.nav-panel.open > :nth-child(5) { transition-delay: 240ms; }
.nav-panel-label { color: var(--n-muted); font: 500 12px/16px var(--n-mono); letter-spacing: 0.08em; text-transform: uppercase; }
.nav-panel-group { display: grid; gap: 12px; }
.nav-panel-group a { display: grid; gap: 0; }
.nav-panel-group b { font-size: 18px; line-height: 28px; font-weight: 600; }
.nav-panel-group span { color: var(--n-muted); font-size: 14px; line-height: 20px; }
.nav-panel-main { display: grid; gap: 16px; padding-top: 24px; border-top: 1px solid var(--n-line-2); }
.nav-panel-main a { font-size: 24px; line-height: 32px; font-weight: 500; }
.nav-panel .cta { justify-self: start; padding: 8px 16px; border-radius: 9999px; background: var(--n-ink); color: var(--n-bg); font-weight: 600; }

/* Room under the bar on pages that start at the very top. */
.nav-space { height: 88px; }

@media (max-width: 960px) {
  .nav .links, .nav > .cta { display: none; }
  .nav .menu { display: block; }
  .nav { width: calc(100% - 32px); padding: 8px 4px 8px 16px; }
  .nav.scrolled { width: calc(100% - 32px); padding: 4px 4px 4px 16px; }
}
@media (prefers-reduced-motion: reduce) {
  .nav, .nav .brand { transition: background-color 300ms linear, border-color 300ms linear; }
  .nav-panel > * { transform: none; }
  .nav .drop-panel, .nav .drop-panel.open { transform: translate(-50%, 0); }
}