:root {
  color-scheme: light;
  --bg: #f7f9fc;
  --surface: #ffffff;
  --text: #172033;
  --muted: #667085;
  --line: #dce3ee;
  --accent: #246bfd;
  --clock: #111827;
  --content-width: 900px;
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0c111b;
  --surface: #151d2b;
  --text: #edf2f7;
  --muted: #a6b0c2;
  --line: #2b374a;
  --accent: #79a3ff;
  --clock: #f8fafc;
}

* { box-sizing: border-box; }

html { background: var(--bg); }

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font: 17px/1.68 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

a { color: var(--accent); }

a:focus-visible, button:focus-visible, input:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 55%, transparent);
  outline-offset: 3px;
}

.shell {
  width: min(calc(100% - 32px), var(--content-width));
  margin: 0 auto;
}

header {
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 76px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  text-decoration: none;
  font-weight: 720;
}

.clock-mark {
  padding: 5px 9px;
  color: var(--surface);
  background: var(--clock);
  border-radius: 5px;
  font: 700 15px/1.1 ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .04em;
}

nav { display: flex; gap: 18px; font-size: 15px; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover { color: var(--text); }

main {
  margin: 48px auto 72px;
  padding: clamp(28px, 5vw, 56px);
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
  box-shadow: 0 18px 50px rgba(25, 42, 70, .08);
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: .11em;
  text-transform: uppercase;
}

h1, h2 { line-height: 1.18; letter-spacing: -.025em; }
h1 { margin: 0 0 14px; font-size: clamp(36px, 6vw, 58px); }
h2 { margin: 38px 0 10px; font-size: 23px; }
p, ul { max-width: 72ch; }
.lede { color: var(--muted); font-size: 20px; }
.meta { color: var(--muted); font-size: 14px; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 16px;
  margin-top: 30px;
}

.card {
  display: block;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 12px;
  color: var(--text);
  text-decoration: none;
}
.card:hover { border-color: var(--accent); }
.card strong { display: block; margin-bottom: 5px; }
.card span { color: var(--muted); }

footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 18px;
  padding: 0 0 42px;
  color: var(--muted);
  font-size: 13px;
}

.controls { display: flex; align-items: center; gap: 10px; }
.controls button {
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text);
  background: var(--surface);
  cursor: pointer;
}
.controls label { display: inline-flex; align-items: center; gap: 7px; }
.controls input { width: 100px; }

@media (max-width: 640px) {
  .header-inner { align-items: flex-start; flex-direction: column; padding: 18px 0; }
  main { margin-top: 24px; padding: 26px 22px; border-radius: 14px; }
  footer { align-items: flex-start; flex-direction: column; }
}