/* AI Keeper design system
   Tokens first, then base, then components. Documented live in design-system.html.
   Light only. Cobalt is the brand, amber marks reclaimable space and nothing else. */

/* ---------- Tokens ---------- */
:root {
  /* Color: surfaces */
  --paper: #ffffff;
  --floor: #f1f3f7;         /* the desk the windows sit on */
  --floor-hi: #f8f9fb;      /* lighter end of the floor gradient */
  --rule: #e3e7ee;
  /* Color: text */
  --ink: #0e1116;
  --ink-2: #2b313b;
  --slate: #5b6472;
  --slate-2: #8a93a1;
  /* Color: brand */
  --cobalt: #2545f5;
  --cobalt-deep: #1a31c4;
  --cobalt-wash: #eaeeff;
  --amber: #f5a624;

  /* Type */
  --font-display: "Bricolage Grotesque", "Helvetica Neue", Arial, sans-serif;
  --font-body: "Hanken Grotesk", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-code: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --fs-sm: 0.9375rem;            /* 15 */
  --fs-base: 1.0625rem;          /* 17 */
  --fs-lg: 1.25rem;              /* 20 */
  --fs-xl: 1.75rem;              /* 28 */
  --fs-2xl: clamp(2rem, 3.6vw, 2.75rem);     /* section heading */
  --fs-3xl: clamp(2.625rem, 6.6vw, 5.25rem); /* hero */

  /* Space: 4pt scale */
  --s-1: 4px; --s-2: 8px; --s-3: 12px; --s-4: 16px; --s-5: 24px; --s-6: 32px;
  --s-7: 48px; --s-8: 64px; --s-9: 96px; --s-10: 144px;

  /* Radius */
  --r-sm: 6px; --r-md: 10px; --r-lg: 20px; --r-xl: 28px;

  /* Elevation. Neutral, layered: a 1px edge, then doubling offset and blur so light reads as
     coming from above. sm for controls, md for panels, lg for the app window. */
  --e-sm: 0 2px 3px -1px rgb(0 0 0 / .10), 0 1px 0 rgb(25 28 33 / .02), 0 0 0 1px rgb(25 28 33 / .08);
  --e-md: 0 0 0 1px rgb(0 0 0 / .06), 0 1px 1px -0.5px rgb(0 0 0 / .06), 0 3px 3px -1.5px rgb(0 0 0 / .06), 0 6px 6px -3px rgb(0 0 0 / .06), 0 12px 12px -6px rgb(0 0 0 / .06), 0 24px 24px -12px rgb(0 0 0 / .06);
  --e-lg: 0 2.8px 2.2px rgb(0 0 0 / .034), 0 6.7px 5.3px rgb(0 0 0 / .048), 0 12.5px 10px rgb(0 0 0 / .06), 0 22.3px 17.9px rgb(0 0 0 / .072), 0 41.8px 33.4px rgb(0 0 0 / .086), 0 100px 80px rgb(0 0 0 / .12);
  --e-1: var(--e-sm);
  --e-2: var(--e-sm);
  --e-3: var(--e-md);
  --e-brand: 0 0 0 1px rgb(26 49 196 / .9), inset 0 1px 0 rgb(255 255 255 / .22), 0 1px 2px rgb(26 49 196 / .35), 0 8px 16px -6px rgb(37 69 245 / .55);

  --ease: cubic-bezier(.2, .7, .2, 1);
  --wrap: 1180px;
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font: 400 var(--fs-base)/1.6 var(--font-body);
  color: var(--slate);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
:focus-visible { outline: 2px solid var(--cobalt); outline-offset: 3px; border-radius: var(--r-sm); }
::selection { background: var(--cobalt-wash); color: var(--ink); }

.wrap { width: min(var(--wrap), 100% - 2 * var(--s-5)); margin-inline: auto; }

/* ---------- Type ---------- */
.display, h1, h2, h3 {
  font-family: var(--font-display);
  font-optical-sizing: auto;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.035em;
  line-height: 1.02;
  text-wrap: balance;
}
h1 { font-size: var(--fs-3xl); letter-spacing: -0.045em; font-weight: 650; line-height: .98; }
h2 { font-size: var(--fs-2xl); }
h3 { font-size: var(--fs-lg); letter-spacing: -0.02em; line-height: 1.2; }
.lead { font-size: var(--fs-lg); line-height: 1.5; color: var(--slate); max-width: 34em; text-wrap: pretty; }
.prose { max-width: 32em; text-wrap: pretty; }
.prose + .prose { margin-top: var(--s-4); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: var(--s-2);
  height: 46px; padding: 0 var(--s-5); border-radius: var(--r-md);
  font: 600 var(--fs-sm)/1 var(--font-body); letter-spacing: -0.005em;
  color: var(--ink); background: var(--paper); box-shadow: var(--e-2);
  border: 0; cursor: pointer; transition: transform .18s var(--ease), box-shadow .18s var(--ease), background .18s;
}
.btn:hover { transform: translateY(-1px); box-shadow: var(--e-3); }
.btn:active { transform: translateY(0); box-shadow: var(--e-1); }
.btn-primary { color: #fff; background: linear-gradient(180deg, #3a58ff, var(--cobalt)); box-shadow: var(--e-brand); }
.btn-primary:hover { box-shadow: var(--e-brand), 0 14px 24px -10px rgb(37 69 245 / .6); }
.btn-sm { height: 38px; padding: 0 var(--s-4); font-size: 14px; }
.link { color: var(--ink); font-weight: 600; border-bottom: 1.5px solid var(--rule); transition: border-color .15s; }
.link:hover { border-color: var(--cobalt); }

/* ---------- Command block ---------- */
.cmd {
  display: flex; align-items: flex-start; gap: var(--s-4); justify-content: space-between;
  padding: var(--s-4) var(--s-4) var(--s-4) var(--s-5);
  border-radius: var(--r-md); background: var(--ink); color: #dfe4ec;
  font: 450 13.5px/1.75 var(--font-code); max-width: 640px;
  box-shadow: 0 0 0 1px rgb(255 255 255 / .06) inset, var(--e-3);
}
.cmd code { white-space: pre-wrap; word-break: break-word; min-width: 0; }
.cmd .p { color: #6b7686; user-select: none; }
.copy {
  flex: none; height: 32px; padding: 0 var(--s-3); border-radius: var(--r-sm);
  border: 1px solid rgb(255 255 255 / .14); background: rgb(255 255 255 / .06); color: #fff;
  font: 600 13px var(--font-body); cursor: pointer; transition: background .15s;
}
.copy:hover { background: rgb(255 255 255 / .14); }

/* ---------- Nav ---------- */
.nav { position: sticky; top: 0; z-index: 20; background: rgb(255 255 255 / .82); -webkit-backdrop-filter: saturate(1.6) blur(16px); backdrop-filter: saturate(1.6) blur(16px); box-shadow: 0 1px 0 var(--rule); }
.nav .wrap { display: flex; align-items: center; gap: var(--s-6); height: 68px; }
.brand { display: flex; align-items: center; gap: var(--s-3); font: 650 19px/1 var(--font-display); letter-spacing: -0.03em; color: var(--ink); }
.brand img { width: 32px; height: 32px; filter: drop-shadow(0 2px 4px rgb(37 69 245 / .35)); }
.nav-links { display: flex; align-items: center; gap: var(--s-6); margin-left: auto; font-size: var(--fs-sm); font-weight: 500; }
.nav-links a:not(.btn):hover { color: var(--ink); }

/* ---------- Hero ---------- */
.hero { padding: var(--s-9) 0 0; }
.hero-head { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: var(--s-8); align-items: end; }
.hero h1 { max-width: 9.5em; }
.hero-side { display: grid; gap: var(--s-5); padding-bottom: var(--s-2); }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: var(--s-5); }
.fine { font-size: 14px; color: var(--slate-2); }

/* The floor: a cool grey band the windows sit on, so shadows have something to fall on. */
.stage { position: relative; margin-top: var(--s-8); padding-bottom: var(--s-9); }
.stage::before { content: ""; position: absolute; inset: 38% 0 0; background: linear-gradient(180deg, var(--paper) 0, var(--floor-hi) 12%, var(--floor) 78%, var(--paper) 100%); }
.stage .wrap { position: relative; }
/* A macOS window: corners are a percentage of the width (26pt on a 1360pt capture), a hairline edge and
   an inner top highlight like AppKit draws, and the neutral layered shadow. */
.win { position: relative; width: 100%; border-radius: 1.88% / 2.6%; box-shadow: var(--e-md); background: #fff; }
.win img { width: 100%; border-radius: inherit; }
.win::after { content: ""; position: absolute; inset: 0; border-radius: inherit; pointer-events: none;
  box-shadow: inset 0 0 0 1px rgb(0 0 0 / .12), inset 0 1px 0 rgb(255 255 255 / .55); }
.win-lg { box-shadow: var(--e-lg); }
.win-dialog { border-radius: 4.73% / 6.34%; max-width: 540px; }
.rise { animation: rise .9s var(--ease) both; animation-delay: .1s; }
@keyframes rise { from { opacity: 0; transform: translateY(24px); } to { opacity: 1; transform: none; } }

/* ---------- Sections ---------- */
.section { padding-top: var(--s-10); }
.split { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); gap: var(--s-8); align-items: start; }
.split-flip { grid-template-columns: minmax(0, 8fr) minmax(0, 4fr); }
.split-flip .copy-col { order: 2; }
.copy-col { position: sticky; top: 108px; }
.copy-col h2 { margin-bottom: var(--s-5); }

/* A plate is the floor with a window set on it. */
.plate { border-radius: var(--r-xl); background: linear-gradient(160deg, var(--floor-hi), var(--floor)); padding: var(--s-8); box-shadow: 0 0 0 1px rgb(14 17 22 / .04) inset; }
.plate-pair { display: grid; grid-template-columns: 1fr 1fr; gap: var(--s-6); align-items: start; }
.plate-pair > :last-child { margin-top: var(--s-8); }
.plate-center { display: grid; place-items: center; }

.wide-head { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: var(--s-8); align-items: end; margin-bottom: var(--s-7); }

/* ---------- Video ---------- */
.video-frame { border-radius: var(--r-xl); overflow: hidden; box-shadow: var(--e-lg); background: var(--floor); aspect-ratio: 16 / 9; }
.video-frame video { display: block; width: 100%; height: 100%; object-fit: cover; }

/* ---------- Terminal windows (the keeper dashboard) ---------- */
.term { background: #0d0e12; border-radius: 12px; overflow: hidden; box-shadow: var(--e-md); max-width: 100%; width: max-content; }
.term-lg { box-shadow: var(--e-lg); }
.term-bar { position: relative; height: 34px; display: flex; align-items: center; gap: 8px; padding: 0 14px; background: #1b1d24; }
.term-bar i { width: 11px; height: 11px; border-radius: 50%; background: #ff5f57; }
.term-bar i:nth-child(2) { background: #febc2e; }
.term-bar i:nth-child(3) { background: #28c840; }
.term-bar span { position: absolute; inset: 0; display: grid; place-items: center; font: 12px var(--font-body); color: #8a93a1; }
.term pre { margin: 0; padding: 14px 18px 18px; color: #dce0e8; font: 12.5px/1.32 var(--font-code); overflow-x: auto; tab-size: 4; }
.term-fig { margin: var(--s-7) 0 0; }
.term-fig:first-of-type { margin-top: 0; }
.term-fig figcaption { margin-bottom: var(--s-3); color: var(--ink); font-weight: 600; }

/* ---------- Index: names and descriptions ---------- */
.index-title { margin-bottom: var(--s-7); max-width: 12em; }
.index { border-top: 1px solid var(--ink); }
.index-row { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); gap: var(--s-6); padding: var(--s-5) 0; border-bottom: 1px solid var(--rule); transition: background .2s; }
.index-row h3 { font-size: var(--fs-xl); letter-spacing: -0.03em; }
.index-row p { max-width: 34em; padding-top: 4px; }

/* ---------- Closing ---------- */
.close { margin-top: var(--s-10); padding: var(--s-10) 0; background: linear-gradient(180deg, var(--paper), var(--floor)); }
.close h2 { font-size: var(--fs-3xl); letter-spacing: -0.045em; max-width: 8em; margin-bottom: var(--s-6); }
.close .lead { margin-bottom: var(--s-6); }
.close .hero-actions { margin-bottom: var(--s-6); }

.foot { padding: var(--s-6) 0; font-size: 14px; color: var(--slate-2); background: var(--floor); box-shadow: 0 -1px 0 var(--rule); }
.foot .wrap { display: flex; flex-wrap: wrap; gap: var(--s-5); align-items: center; }
.foot nav { margin-left: auto; display: flex; gap: var(--s-5); }
.foot a:hover { color: var(--ink); }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .hero { padding-top: var(--s-8); }
  .hero-head, .split, .split-flip, .wide-head, .index-row { grid-template-columns: 1fr; gap: var(--s-5); }
  .split-flip .copy-col { order: 0; }
  .copy-col { position: static; }
  .section { padding-top: var(--s-9); }
  .stage { margin-top: var(--s-7); padding-bottom: var(--s-8); }
  .plate { padding: var(--s-4); border-radius: var(--r-lg); }
  .plate-pair { grid-template-columns: 1fr; }
  .plate-pair > :last-child { margin-top: 0; }
  .nav-links a:not(.btn) { display: none; }
  .nav .wrap { height: 60px; }
  .close { margin-top: var(--s-9); padding: var(--s-9) 0; }
  .index-row { padding: var(--s-4) 0; gap: var(--s-2); }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .rise { animation: none; }
  .btn { transition: none; }
}