/* kernable.com – light, typographic layout in the logo's colours.
   Fonts are self-hosted (SIL OFL, see assets/fonts/OFL-*.txt). */

@font-face { font-family: "Archivo"; src: url("fonts/archivo-latin-700-normal.woff2") format("woff2"); font-weight: 700; font-display: swap; }
@font-face { font-family: "Archivo"; src: url("fonts/archivo-latin-800-normal.woff2") format("woff2"); font-weight: 800; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("fonts/ibm-plex-sans-latin-400-normal.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("fonts/ibm-plex-sans-latin-500-normal.woff2") format("woff2"); font-weight: 500; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("fonts/ibm-plex-sans-latin-600-normal.woff2") format("woff2"); font-weight: 600; font-display: swap; }
@font-face { font-family: "IBM Plex Mono"; src: url("fonts/ibm-plex-mono-latin-400-normal.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "IBM Plex Mono"; src: url("fonts/ibm-plex-mono-latin-500-normal.woff2") format("woff2"); font-weight: 500; font-display: swap; }

:root {
  --bg: #ffffff;
  --bg-raised: #f5f7fb;
  --panel: #ffffff;
  --code-bg: #0a1430;
  --line: #e2e7ef;
  --line-strong: #c9d1dd;
  --ink: #0a1430;
  --ink-soft: #46526a;
  --ink-mute: #7c879a;
  --cyan: #00c8f0;
  --blue: #0b3cff;
  --violet: #7a4dff;
  --accent: var(--blue);
  --accent-soft: rgba(11, 60, 255, 0.08);
  --topbar-bg: rgba(255, 255, 255, 0.86);
  --glass: rgba(255, 255, 255, 0.8);
  --gradient: linear-gradient(100deg, var(--cyan) 0%, var(--blue) 48%, var(--violet) 100%);
  --ok: #0f9d6e;
  --display: "Archivo", system-ui, -apple-system, sans-serif;
  --sans: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --wrap: 1120px;
  color-scheme: light;
}

/* Dark theme: follows the system unless the visitor picked one (data-theme on <html>). */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #070b18; --bg-raised: #0b1122; --panel: #0c1326; --code-bg: #0e1733;
    --line: #1b2440; --line-strong: #2b3657;
    --ink: #eaf0fb; --ink-soft: #a9b4cc; --ink-mute: #6f7c98;
    --accent: #5b8cff; --accent-soft: rgba(91, 140, 255, 0.12);
    --topbar-bg: rgba(7, 11, 24, 0.82); --glass: rgba(7, 11, 24, 0.7);
    color-scheme: dark;
  }
  :root:not([data-theme="light"]) .logo-light { display: none; }
  :root:not([data-theme="light"]) .logo-dark { display: block; }
  :root:not([data-theme="light"]) .theme-toggle .moon { display: none; }
  :root:not([data-theme="light"]) .theme-toggle .sun { display: block; }
}
:root[data-theme="dark"] {
  --bg: #070b18; --bg-raised: #0b1122; --panel: #0c1326; --code-bg: #0e1733;
  --line: #1b2440; --line-strong: #2b3657;
  --ink: #eaf0fb; --ink-soft: #a9b4cc; --ink-mute: #6f7c98;
  --accent: #5b8cff; --accent-soft: rgba(91, 140, 255, 0.12);
  --topbar-bg: rgba(7, 11, 24, 0.82); --glass: rgba(7, 11, 24, 0.7);
  color-scheme: dark;
}
:root[data-theme="dark"] .logo-light { display: none; }
:root[data-theme="dark"] .logo-dark { display: block; }
:root[data-theme="dark"] .theme-toggle .moon { display: none; }
:root[data-theme="dark"] .theme-toggle .sun { display: block; }

* { box-sizing: border-box; }
html { background: var(--bg); scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  margin: 0; min-height: 100vh; display: flex; flex-direction: column;
  background: var(--bg); color: var(--ink);
  font: 400 16px/1.6 var(--sans);
  -webkit-font-smoothing: antialiased;
}
main { flex: 1; }
a { color: var(--ink); text-decoration-color: var(--line-strong); text-underline-offset: 3px; }
a:hover { text-decoration-color: var(--accent); }
::selection { background: var(--blue); color: #fff; }
code { white-space: nowrap; font: 400 0.9em/1 var(--mono); background: var(--bg-raised); border: 1px solid var(--line); padding: 2px 5px; }

h1, h2, h3 { font-family: var(--display); color: var(--ink); margin: 0; }
h2 { font-weight: 800; font-size: clamp(1.6rem, 3.2vw, 2.2rem); letter-spacing: -0.03em; line-height: 1.12; }
h3 { font-weight: 700; font-size: 1.1rem; letter-spacing: -0.01em; }
p { color: var(--ink-soft); }
strong { color: var(--ink); font-weight: 600; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.grad { background: var(--gradient); -webkit-background-clip: text; background-clip: text; color: transparent; }

/* Labels in mono caps, e.g. "[ THE KERNEL ]" */
.eyebrow, .tag { font: 400 12px/1.4 var(--mono); text-transform: uppercase; letter-spacing: 0.14em; color: var(--ink-mute); }
.eyebrow { margin: 0 0 22px; }
.eyebrow em { font-style: normal; color: var(--accent); }

/* ---------- Header / footer ---------- */

.topbar { position: sticky; top: 0; z-index: 10; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 16px max(24px, calc((100% - var(--wrap)) / 2 + 24px)); background: var(--topbar-bg); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; }
.brand img { height: 26px; width: auto; display: block; }
.brand .logo-dark { display: none; }
.theme-toggle { display: inline-grid; place-items: center; width: 34px; height: 34px; padding: 0; background: none; border: 1px solid var(--line); color: var(--ink-soft); cursor: pointer; }
.theme-toggle:hover { color: var(--ink); border-color: var(--line-strong); }
.theme-toggle svg { width: 16px; height: 16px; }
.theme-toggle .sun { display: none; }
.topbar nav { display: flex; align-items: center; gap: 26px; font: 400 12.5px/1 var(--mono); letter-spacing: 0.04em; }
.topbar nav a { color: var(--ink-soft); text-decoration: none; }
.topbar nav a:hover { color: var(--ink); }
.topbar nav .nav-box { color: var(--ink); border: 1px solid var(--line-strong); padding: 9px 14px; }
.topbar nav .nav-box:hover { border-color: var(--ink); }

.footer { border-top: 1px solid var(--line); padding: 28px max(24px, calc((100% - var(--wrap)) / 2 + 24px)); font: 400 11.5px/1.6 var(--mono); letter-spacing: 0.06em; color: var(--ink-mute); display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.footer a { color: var(--ink-mute); }
.footer nav { display: flex; gap: 22px; flex-wrap: wrap; }

/* ---------- Buttons ---------- */

.button { display: inline-flex; align-items: center; gap: 10px; padding: 14px 20px; border: 1px solid var(--line-strong); background: var(--bg); color: var(--ink); text-decoration: none; font: 400 12.5px/1 var(--mono); letter-spacing: 0.06em; cursor: pointer; transition: border-color 0.15s, background 0.15s, color 0.15s; }
.button:hover { border-color: var(--ink); }
.button.primary { background: var(--ink); border-color: var(--ink); color: var(--bg); }
.button.primary:hover { background: var(--blue); border-color: var(--blue); color: #fff; }
.button .arrow { transition: transform 0.15s; }
.button:hover .arrow { transform: translateX(3px); }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin: 36px 0 0; }

/* ---------- Hero ---------- */

.hero { position: relative; overflow: hidden; border-bottom: 1px solid var(--line); }
.hero-log { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; }
.hero-inner { position: relative; padding: 132px 24px 140px; }
.hero h1 { font-weight: 800; font-size: clamp(2.6rem, 6.4vw, 4.6rem); letter-spacing: -0.045em; line-height: 1; margin: 0 0 28px; max-width: 700px; }
.hero .lead { font-size: 1.15rem; line-height: 1.65; max-width: 520px; margin: 0; }
.install { display: inline-flex; align-items: center; gap: 12px; margin-top: 28px; font: 400 13px/1 var(--mono); color: var(--ink-mute); }
.install code { padding: 8px 12px; color: var(--ink); background: var(--glass); }
.soon { font: 500 10.5px/1 var(--mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--violet); border: 1px solid rgba(122, 77, 255, 0.35); padding: 4px 7px; white-space: nowrap; }

/* ---------- Sections ---------- */

.lp-section { padding: 112px 0; border-bottom: 1px solid var(--line); }
.lp-section.raised { background: var(--bg-raised); }
.split { display: grid; grid-template-columns: 240px 1fr; gap: 48px; }
.split .tag { padding-top: 10px; }
.split-body { max-width: 680px; }
.split-body h2 { margin-bottom: 20px; }
.split-body p { font-size: 1.05rem; line-height: 1.7; margin: 0 0 16px; }


/* Faint vertical lines on the content grid, behind the hero and the closing section. */
.gridlines { position: absolute; inset: 0; margin: 0 auto; width: calc(min(100%, var(--wrap)) - 48px); pointer-events: none; border-left: 1px solid var(--line); border-right: 1px solid var(--line); background: linear-gradient(to right, var(--line) 1px, transparent 1px) 0 0 / 25% 100% repeat-x; opacity: 0.7; }

/* Ticker below the hero */
.ticker { overflow: hidden; background: var(--gradient); color: #fff; border-bottom: 1px solid var(--line); }
.ticker-track { display: flex; width: max-content; animation: ticker 40s linear infinite; }
.ticker-track > div { display: flex; }
.ticker span { font: 500 11.5px/1 var(--mono); letter-spacing: 0.16em; text-transform: uppercase; padding: 14px 0; white-space: nowrap; }
.ticker span::after { content: ""; display: inline-block; width: 5px; height: 5px; background: rgba(255, 255, 255, 0.75); margin: 0 28px; vertical-align: 2px; }
@keyframes ticker { to { transform: translateX(-50%); } }

/* Before -> after */
.shift { list-style: none; margin: 56px 0 0; padding: 0; border: 1px solid var(--line); background: var(--panel); }
.shift li { display: grid; grid-template-columns: 48px 1fr 40px 1fr; align-items: center; gap: 16px; padding: 22px 28px; }
.shift li + li { border-top: 1px solid var(--line); }
.shift .n { font: 400 11px/1 var(--mono); color: var(--ink-mute); letter-spacing: 0.1em; }
.shift s { color: var(--ink-mute); font-size: 1.05rem; text-decoration-color: var(--ink-mute); }
.shift .to { color: var(--accent); font-size: 1.1rem; }
.shift strong { font: 700 clamp(1.15rem, 2.2vw, 1.5rem)/1.2 var(--display); letter-spacing: -0.02em; }
.shift strong code { font-size: 0.8em; padding: 4px 8px; }

/* Architecture diagram: processes above, the kernel below. */
.arch { margin-top: 56px; }
.arch-procs { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.proc { border: 1px solid var(--line); background: var(--panel); padding: 20px 20px 18px; position: relative; }
.proc::before { content: ""; position: absolute; left: 0; top: 0; width: 100%; height: 2px; background: var(--gradient); }
.proc strong { display: block; font: 700 1rem/1.3 var(--display); }
.proc span { display: block; font: 400 11.5px/1.5 var(--mono); color: var(--ink-mute); margin-top: 6px; }
.proc p { margin: 10px 0 0; font-size: 0.9rem; line-height: 1.55; }
.arch-wire { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; height: 56px; }
.arch-wire div { position: relative; }
.arch-wire div::before { content: ""; position: absolute; left: 50%; top: 0; bottom: 0; border-left: 1px dashed var(--line-strong); }
.arch-wire div:first-child::after { content: "gRPC · signed"; position: absolute; left: calc(50% + 12px); top: 50%; transform: translateY(-50%); font: 400 11px/1 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-mute); white-space: nowrap; }
.kernel { background: var(--code-bg); color: #fff; padding: 28px 28px 24px; position: relative; overflow: hidden; }
.kernel::after { content: ""; position: absolute; left: 0; bottom: 0; width: 100%; height: 3px; background: var(--gradient); }
.kernel-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.kernel-head strong { color: #fff; font: 800 1.35rem/1 var(--display); letter-spacing: -0.02em; }
.kernel-head span { font: 400 11.5px/1 var(--mono); letter-spacing: 0.1em; text-transform: uppercase; color: #8d9ab8; }
.kernel ul { list-style: none; margin: 22px 0 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; border-top: 1px solid #1f2b4d; }
.kernel li { padding: 16px 16px 4px 0; font-size: 0.92rem; line-height: 1.5; color: #b9c3da; }
.kernel li b { display: block; color: #fff; font: 500 12px/1.4 var(--mono); letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 6px; }

.ops { list-style: none; margin: 28px 0 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.ops li { color: var(--ink-soft); font-size: 0.95rem; line-height: 1.6; padding-left: 16px; border-left: 2px solid var(--line-strong); }
.limits { margin: 28px 0 0; font-size: 0.95rem; }

/* Code tabs */
.code { margin-top: 56px; border: 1px solid var(--line-strong); background: var(--code-bg); }
.code-tabs { display: flex; flex-wrap: wrap; border-bottom: 1px solid #1f2b4d; }
.code-tabs button { background: none; border: 0; border-right: 1px solid #1f2b4d; color: #8d9ab8; font: 400 12px/1 var(--mono); letter-spacing: 0.04em; padding: 16px 20px; cursor: pointer; text-align: left; }
.code-tabs button b { display: block; font-weight: 500; color: inherit; margin-bottom: 6px; }
.code-tabs button[aria-selected="true"] { color: #fff; box-shadow: inset 0 -2px 0 var(--cyan); }
.code-tabs button:hover { color: #fff; }
.code pre { margin: 0; padding: 28px; overflow-x: auto; font: 400 13.5px/1.7 var(--mono); color: #dbe3f5; }
.code pre[hidden] { display: none; }
.code .c { color: #6f7f9f; }
.code .k { color: #9bb8ff; }
.code .s { color: #7fe3f5; }
.code .f { color: #c5b0ff; }
.code-note { margin: 18px 0 0; font-size: 0.95rem; }

/* Comparison table */
.table-wrap { margin-top: 56px; overflow-x: auto; border: 1px solid var(--line); background: var(--panel); }
table.compare { width: 100%; border-collapse: collapse; font-size: 0.9rem; min-width: 820px; }
.compare th, .compare td { text-align: left; vertical-align: top; padding: 14px 16px; border-bottom: 1px solid var(--line); line-height: 1.5; }
.compare thead th { font: 500 11px/1.4 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-mute); background: var(--bg-raised); }
.compare tbody th { font-weight: 500; color: var(--ink); width: 18%; }
.compare td { color: var(--ink-soft); }
.compare .us { background: var(--accent-soft); color: var(--ink); }
.compare thead .us { color: var(--accent); }
.compare tr:last-child th, .compare tr:last-child td { border-bottom: 0; }


/* Editions */
.editions { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-top: 56px; }
.edition { border: 1px solid var(--line); background: var(--panel); padding: 36px 32px; }
.edition.featured { border-color: var(--ink); }
.edition h3 { font-size: 1.5rem; margin: 14px 0 6px; }
.edition .price { font: 500 13px/1.4 var(--mono); color: var(--ink-mute); margin: 0 0 22px; }
.edition ul { margin: 0; padding: 0; list-style: none; }
.edition li { padding: 10px 0 10px 22px; border-top: 1px solid var(--line); position: relative; font-size: 0.95rem; color: var(--ink-soft); }
.edition li::before { content: ""; position: absolute; left: 2px; top: 18px; width: 8px; height: 8px; background: var(--gradient); }

.cta { padding: 120px 0; position: relative; overflow: hidden; }
.cta .wrap { position: relative; }
.cta::before { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 3px; background: var(--gradient); }
.cta h2 { font-size: clamp(2rem, 4.5vw, 3rem); letter-spacing: -0.035em; margin-bottom: 18px; }
.cta p { max-width: 580px; font-size: 1.05rem; margin: 0; }

/* Legal pages */
.prose { max-width: 780px; padding-top: 72px; padding-bottom: 96px; }
.prose h1 { font-weight: 800; font-size: clamp(2.2rem, 5vw, 2.8rem); letter-spacing: -0.035em; line-height: 1.05; margin-bottom: 12px; }
.prose h2 { font-size: 1.2rem; letter-spacing: -0.015em; margin: 36px 0 8px; }
.prose p { margin: 0 0 12px; line-height: 1.7; }
.prose .muted { color: var(--ink-mute); }

@media (prefers-reduced-motion: reduce) { * { transition: none !important; } .ticker-track { animation: none; } html { scroll-behavior: auto; } }

@media (max-width: 960px) {
  .arch-procs, .arch-wire, .kernel ul { grid-template-columns: 1fr 1fr; }
  .arch-wire div:nth-child(n + 3) { display: none; }
}

@media (max-width: 800px) {
  .topbar nav .hide-sm { display: none; }
  .wrap { padding: 0 16px; }
  .hero-inner { padding: 88px 16px 96px; }
  .hero-log { opacity: 0.35; }
  .lp-section, .cta { padding: 72px 0; }
  .split { grid-template-columns: 1fr; gap: 16px; }
  .editions, .ops { grid-template-columns: 1fr; }
  .install { flex-wrap: wrap; }
  .gridlines { width: calc(100% - 32px); }
  .shift li { grid-template-columns: 32px 1fr; gap: 6px 12px; padding: 18px 16px; }
  .shift .to { display: none; }
  .shift strong { grid-column: 2; }
  .install code { word-break: break-all; }
}

@media (max-width: 520px) {
  .arch-procs, .kernel ul { grid-template-columns: 1fr; }
  .arch-wire { grid-template-columns: 1fr; height: 40px; }
  .arch-wire div:nth-child(n + 2) { display: none; }
  .code pre { padding: 20px 16px; font-size: 12.5px; }
}