/* Engram site. No framework, no external requests. */

:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --surface-2: #f3f1ec;
  --text: #1b1a17;
  --muted: #5f5b53;
  --border: #e3dfd6;
  --accent: #3b5bdb;
  --accent-soft: #e7ecfd;
  --warm: #b35c1e;
  --warm-soft: #fbeee3;
  --code-bg: #f3f1ec;
  --shadow: 0 1px 2px rgb(0 0 0 / 0.04), 0 4px 16px rgb(0 0 0 / 0.04);
  --radius: 14px;
  --maxw: 1080px;
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1012;
    --surface: #17181b;
    --surface-2: #1e2024;
    --text: #ecebe8;
    --muted: #a3a09a;
    --border: #2c2e33;
    --accent: #8ea5ff;
    --accent-soft: #1d2440;
    --warm: #f0a46b;
    --warm-soft: #2e2119;
    --code-bg: #1e2024;
    --shadow: none;
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #0f1012;
  --surface: #17181b;
  --surface-2: #1e2024;
  --text: #ecebe8;
  --muted: #a3a09a;
  --border: #2c2e33;
  --accent: #8ea5ff;
  --accent-soft: #1d2440;
  --warm: #f0a46b;
  --warm-soft: #2e2119;
  --code-bg: #1e2024;
  --shadow: none;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  overflow-x: hidden;
}

a { color: var(--accent); text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 16px; }
@media (min-width: 720px) { .wrap { padding: 0 32px; } }

/* Header */
.top {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: saturate(1.4) blur(10px);
  -webkit-backdrop-filter: saturate(1.4) blur(10px);
  border-bottom: 1px solid var(--border);
}
.top .wrap { display: flex; align-items: center; gap: 16px; height: 56px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 650; color: var(--text); text-decoration: none; letter-spacing: -0.01em; }
.brand svg { width: 22px; height: 22px; }
.nav { display: none; gap: 20px; margin-left: auto; }
.nav a { color: var(--muted); text-decoration: none; font-size: 15px; }
.nav a:hover { color: var(--text); }
@media (min-width: 820px) { .nav { display: flex; } }
.actions { display: flex; gap: 8px; margin-left: auto; }
@media (min-width: 820px) { .actions { margin-left: 8px; } }
.icon-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  height: 36px; min-width: 36px; padding: 0 10px;
  border: 1px solid var(--border); border-radius: 10px;
  background: var(--surface); color: var(--text);
  font: inherit; font-size: 14px; cursor: pointer; text-decoration: none;
}
.icon-btn:hover { background: var(--surface-2); }
.icon-btn svg { width: 18px; height: 18px; }

/* Hero */
.hero { padding: 72px 0 48px; }
@media (min-width: 720px) { .hero { padding: 112px 0 72px; } }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase;
  color: var(--warm); background: var(--warm-soft);
  padding: 4px 10px; border-radius: 999px;
}
.hero h1 {
  font-size: clamp(44px, 9vw, 88px); line-height: 1; letter-spacing: -0.035em;
  margin: 20px 0 16px; font-weight: 750;
}
.hero .tagline { font-size: clamp(20px, 3.2vw, 28px); line-height: 1.35; color: var(--text); max-width: 760px; margin: 0 0 16px; letter-spacing: -0.01em; }
.hero .lede { color: var(--muted); max-width: 680px; margin: 0 0 28px; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 18px; border-radius: 12px; font-weight: 600; font-size: 16px; text-decoration: none;
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
}
.btn.primary { background: var(--text); color: var(--bg); border-color: var(--text); }
.btn:hover { transform: translateY(-1px); }
.badges { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 28px; }
.badge { font-family: var(--mono); font-size: 12.5px; padding: 3px 9px; border: 1px solid var(--border); border-radius: 6px; color: var(--muted); background: var(--surface); }

/* Sections */
section { padding: 56px 0; border-top: 1px solid var(--border); scroll-margin-top: 64px; }
@media (min-width: 720px) { section { padding: 80px 0; } }
.kicker { font-size: 13px; font-weight: 650; letter-spacing: 0.06em; text-transform: uppercase; color: var(--accent); margin: 0 0 8px; }
h2 { font-size: clamp(28px, 4.4vw, 40px); line-height: 1.15; letter-spacing: -0.025em; margin: 0 0 16px; font-weight: 720; }
h3 { font-size: 19px; line-height: 1.3; margin: 0 0 8px; letter-spacing: -0.01em; }
.intro { color: var(--muted); max-width: 720px; margin: 0 0 32px; font-size: 18px; }

.grid { display: grid; gap: 16px; }
@media (min-width: 720px) { .grid.two { grid-template-columns: 1fr 1fr; } .grid.three { grid-template-columns: repeat(3, 1fr); } .grid.four { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .grid.four { grid-template-columns: repeat(4, 1fr); } }

.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px; box-shadow: var(--shadow);
}
.card p { margin: 0; color: var(--muted); font-size: 16px; }
.card .tag { display: inline-block; font-family: var(--mono); font-size: 12px; color: var(--accent); background: var(--accent-soft); border-radius: 6px; padding: 2px 8px; margin-bottom: 12px; }

/* Why: comparison */
.compare { display: grid; gap: 16px; }
@media (min-width: 820px) { .compare { grid-template-columns: 1fr 1fr; } }
.compare .card h3 { display: flex; align-items: center; gap: 10px; }
.compare ul { margin: 12px 0 0; padding-left: 20px; color: var(--muted); font-size: 16px; }
.compare li + li { margin-top: 6px; }
.dot { width: 10px; height: 10px; border-radius: 50%; display: inline-block; flex: none; }
.dot.warm { background: var(--warm); }
.dot.cool { background: var(--accent); }

/* Architecture */
.arch { display: grid; gap: 32px; align-items: start; }
@media (min-width: 900px) { .arch { grid-template-columns: 440px 1fr; gap: 48px; } }
.diagram { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 12px; box-shadow: var(--shadow); }
.diagram svg { display: block; width: 100%; height: auto; max-width: 460px; margin: 0 auto; }
.d-box { fill: var(--surface-2); stroke: var(--border); stroke-width: 1.5; }
.d-base { fill: var(--surface-2); stroke: var(--text); stroke-width: 1.5; }
.d-fast { fill: var(--accent-soft); stroke: var(--accent); stroke-width: 1.5; }
.d-slow { fill: var(--warm-soft); stroke: var(--warm); stroke-width: 1.5; }
.d-vault { fill: none; stroke: var(--muted); stroke-width: 1.25; stroke-dasharray: 6 5; }
.d-line { stroke: var(--muted); stroke-width: 1.5; fill: none; }
.d-line.dash { stroke-dasharray: 4 4; }
.d-head { fill: var(--muted); }
.d-title { fill: var(--text); font: 650 15px var(--font); }
.d-sub { fill: var(--muted); font: 400 12.5px var(--font); }
.d-label { fill: var(--muted); font: 500 12px var(--font); }
.d-label.accent { fill: var(--accent); }
.d-label.warm { fill: var(--warm); }
.steps { counter-reset: s; list-style: none; margin: 0; padding: 0; display: grid; gap: 18px; }
.steps li { position: relative; padding-left: 44px; }
.steps li::before {
  counter-increment: s; content: counter(s);
  position: absolute; left: 0; top: 0; width: 30px; height: 30px; border-radius: 50%;
  display: grid; place-items: center; font-size: 14px; font-weight: 700;
  background: var(--surface-2); border: 1px solid var(--border); color: var(--text);
}
.steps h3 { margin-bottom: 4px; font-size: 18px; }
.steps p { margin: 0; color: var(--muted); font-size: 16px; }

/* Roadmap */
.phases { list-style: none; margin: 0; padding: 0; display: grid; gap: 16px; }
@media (min-width: 720px) { .phases { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .phases { grid-template-columns: repeat(4, 1fr); } }
.phase { position: relative; }
.phase .num { font-family: var(--mono); font-size: 13px; color: var(--muted); }
.phase.now { border-color: var(--accent); }
.phase.now .num { color: var(--accent); font-weight: 650; }
.phase ul { margin: 10px 0 0; padding-left: 18px; color: var(--muted); font-size: 15px; }
.phase li + li { margin-top: 4px; }

/* Research */
.doc-link { display: block; text-decoration: none; color: inherit; transition: border-color 0.15s; }
.doc-link:hover { border-color: var(--accent); }
.doc-link h3 { color: var(--text); }
.doc-link .path { font-family: var(--mono); font-size: 12.5px; color: var(--accent); margin-bottom: 8px; display: block; }
.finding { border-left: 3px solid var(--accent); padding: 4px 0 4px 16px; margin: 32px 0 0; max-width: 820px; }
.finding p { margin: 0 0 8px; }
.finding p:last-child { margin: 0; color: var(--muted); font-size: 15px; }

/* Status */
.status-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 8px; }
.pill { display: inline-flex; align-items: center; gap: 8px; font-size: 15px; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--border); background: var(--surface); }
.pill .dot { width: 8px; height: 8px; }
.pill.done .dot { background: #2f9e44; }
.pill.wip .dot { background: var(--warm); }
.pill.todo .dot { background: var(--border); }

/* Citation */
.cite { position: relative; }
pre {
  margin: 0; background: var(--code-bg); border: 1px solid var(--border); border-radius: 12px;
  padding: 18px; overflow-x: auto; font-family: var(--mono); font-size: 13.5px; line-height: 1.55;
  white-space: pre; max-width: 100%;
}
.copy { position: absolute; top: 10px; right: 10px; }

footer { border-top: 1px solid var(--border); padding: 32px 0 48px; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 12px 24px; justify-content: space-between; }
footer a { color: var(--muted); }