/* gpu4.you — minimal type-driven styles. No JS. <20KB gzipped target.
   Color: dark by default; light mode via prefers-color-scheme.
   Type: system font stack, fluid sizing, generous line-height.
   Layout: single column, max 720px, centered. */

:root {
  color-scheme: light dark;
  --bg: #0b0c10;
  --fg: #e8e8e8;
  --fg-dim: #a8a8a8;
  --accent: #7ad7ff;
  --accent-warm: #ffd17a;
  --rule: rgba(255,255,255,.10);
  --code-bg: rgba(255,255,255,.05);
  --pass: #6dd47b;
}
@media (prefers-color-scheme: light) {
  :root {
    --bg: #fafaf7;
    --fg: #14181f;
    --fg-dim: #5a6271;
    --accent: #1a6fb4;
    --accent-warm: #b06900;
    --rule: rgba(0,0,0,.10);
    --code-bg: rgba(0,0,0,.05);
    --pass: #1a8a35;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, "SF Pro", system-ui, sans-serif;
  font-size: clamp(16px, 0.95rem + 0.2vw, 18px);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 2px; }

.skip {
  position: absolute; left: -9999px; top: 0;
  background: var(--accent); color: var(--bg); padding: .5rem 1rem; z-index: 100;
}
.skip:focus { left: 1rem; top: 1rem; }

header {
  border-bottom: 1px solid var(--rule);
}
header nav {
  max-width: 720px;
  margin: 0 auto;
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}
nav .logo {
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -.02em;
  color: var(--fg);
  text-decoration: none;
  margin-right: auto;
}
nav .logo .dot { color: var(--accent); }
nav a[aria-current="page"] { color: var(--accent); text-decoration: none; }

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}

h1, h2, h3 {
  letter-spacing: -.015em;
  line-height: 1.2;
}
h1 {
  font-size: clamp(1.9rem, 1.4rem + 2.2vw, 2.6rem);
  margin: 0 0 1rem;
  font-weight: 700;
}
h2 {
  font-size: clamp(1.35rem, 1.1rem + 1vw, 1.6rem);
  margin: 2.4rem 0 0.6rem;
  font-weight: 600;
}
h3 {
  font-size: 1.1rem;
  margin: 1.4rem 0 0.4rem;
  font-weight: 600;
}
p, li, dd { margin: 0 0 0.9rem; }
ul, ol { padding-left: 1.25rem; margin: 0 0 1rem; }

.lede {
  font-size: clamp(1.05rem, 1rem + 0.4vw, 1.2rem);
  color: var(--fg);
  margin-bottom: 1.4rem;
}
.kicker {
  font-size: 0.85rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--fg-dim);
  margin: 0 0 .4rem;
}
.footnote {
  font-size: .9rem;
  color: var(--fg-dim);
  border-left: 2px solid var(--rule);
  padding-left: .9rem;
  margin-top: 1.5rem;
}

/* hero / sections */
.hero { margin-top: 1.5rem; }
section { margin: 2.5rem 0; }
section.signup, section.proof, section.thesis { padding-top: 1.2rem; border-top: 1px solid var(--rule); }

.numbers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: .9rem 1.25rem;
  margin: 1.2rem 0 1rem;
  padding: 0;
}
.numbers > div { margin: 0; }
.numbers dt {
  font-weight: 700;
  font-size: clamp(1.4rem, 1.1rem + 1.2vw, 1.8rem);
  letter-spacing: -.02em;
  color: var(--accent-warm);
}
.numbers dd { margin: .15rem 0 0; color: var(--fg-dim); font-size: .95rem; }
.pass { color: var(--pass); font-weight: 600; letter-spacing: .03em; }

/* form */
form {
  display: grid;
  gap: .55rem;
  margin: 1rem 0 .8rem;
  max-width: 460px;
}
label {
  font-size: .9rem;
  color: var(--fg-dim);
}
input[type="email"], select {
  font: inherit;
  padding: .65rem .8rem;
  border-radius: 6px;
  border: 1px solid var(--rule);
  background: var(--code-bg);
  color: var(--fg);
  width: 100%;
  appearance: none;
  -webkit-appearance: none;
}
input[type="email"]:focus, select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
  border-color: var(--accent);
}
button[type="submit"] {
  font: inherit;
  font-weight: 600;
  padding: .7rem 1rem;
  border-radius: 6px;
  border: 0;
  background: var(--accent);
  color: #0b0c10;
  cursor: pointer;
  margin-top: .5rem;
  letter-spacing: -.005em;
}
button[type="submit"]:hover { filter: brightness(1.05); }
button[type="submit"]:focus-visible { outline: 2px solid var(--fg); outline-offset: 2px; }

.privacy { color: var(--fg-dim); }
.nojs-note { color: var(--fg-dim); font-size: .85rem; }

/* prose pages */
.prose article { font-size: 1rem; }
.prose .article-head { margin-bottom: 1.6rem; padding-bottom: .8rem; border-bottom: 1px solid var(--rule); }

pre {
  overflow-x: auto;
  background: var(--code-bg);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: .9rem 1rem;
  font-size: .85rem;
  line-height: 1.5;
}
code { font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace; font-size: .92em; }
:not(pre) > code { background: var(--code-bg); padding: .1rem .35rem; border-radius: 3px; }

.cta { margin-top: 2rem; }
.button {
  display: inline-block;
  padding: .7rem 1.1rem;
  background: var(--accent);
  color: #0b0c10;
  text-decoration: none;
  border-radius: 6px;
  font-weight: 600;
}

/* footer */
footer {
  border-top: 1px solid var(--rule);
  padding: 1.4rem 1.25rem 2rem;
  max-width: 720px;
  margin: 2rem auto 0;
}
footer p { margin: .25rem 0; color: var(--fg-dim); font-size: .92rem; }
footer .meta small { color: var(--fg-dim); opacity: .8; }