:root {
  --bg: #10131a;
  --panel: #171b24;
  --line: #262c39;
  --ink: #e6e9ef;
  --dim: #99a2b4;
  --accent: #6fd3c7;
  --good: #57c98a;
  --bad: #e8736b;
  --warn: #e0b45e;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  padding: 0 1rem 4rem;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

header, main { max-width: 46rem; margin: 0 auto; }

header { padding: 3rem 0 1rem; border-bottom: 1px solid var(--line); }

h1 {
  margin: 0;
  font-size: clamp(2rem, 8vw, 3rem);
  letter-spacing: -0.02em;
}

.tagline { margin: .25rem 0 1.5rem; color: var(--accent); font-size: 1.1rem; }

.lede { font-size: 1.05rem; }

h2 {
  margin: 3rem 0 .75rem;
  font-size: 1.4rem;
  letter-spacing: -0.01em;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

h3 { margin: 2rem 0 .5rem; font-size: 1.05rem; color: var(--accent); }

section:first-of-type h2 { border-top: 0; }

p { margin: .75rem 0; }

.rule {
  font-size: 1.15rem;
  padding: 1rem;
  background: var(--panel);
  border-left: 3px solid var(--accent);
  border-radius: 0 6px 6px 0;
}

.aside { color: var(--dim); font-size: .95rem; }

blockquote {
  margin: 1rem 0;
  padding: .75rem 1rem;
  background: var(--panel);
  border-left: 3px solid var(--line);
  border-radius: 0 6px 6px 0;
  color: var(--dim);
  font-size: .95rem;
}

.callout {
  padding: 1rem;
  background: var(--panel);
  border: 1px solid var(--warn);
  border-radius: 6px;
}

code, pre, .grid, textarea, select {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

code { background: var(--panel); padding: .1em .35em; border-radius: 3px; font-size: .9em; }

.digest { word-break: break-all; }

pre.code, pre.grid {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: .9rem;
  overflow-x: auto;
  font-size: .85rem;
  line-height: 1.5;
}

.two-up { display: flex; flex-wrap: wrap; gap: 1rem; }
.two-up figure { margin: 0; flex: 1 1 12rem; }
.two-up figcaption { color: var(--dim); font-size: .85rem; margin-top: .35rem; }

pre.grid { font-size: 1rem; letter-spacing: .12em; text-align: center; }
pre.grid.solved { color: var(--accent); }

ol.steps, ul { padding-left: 1.2rem; }
ol.steps li { margin: .75rem 0; }

table { border-collapse: collapse; width: 100%; font-size: .95rem; }
th, td { text-align: left; padding: .4rem .6rem; border-bottom: 1px solid var(--line); }
th { color: var(--dim); font-weight: 600; }

.control { margin: 1rem 0; }
.control label { display: block; margin-bottom: .35rem; color: var(--dim); font-size: .9rem; }

select, textarea, input[type=file] {
  width: 100%;
  background: var(--panel);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: .6rem;
  font-size: .9rem;
}

textarea { resize: vertical; white-space: pre; }

button {
  margin-top: .5rem;
  background: var(--accent);
  color: #0d1116;
  border: 0;
  border-radius: 6px;
  padding: .6rem 1.1rem;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
button:active { transform: translateY(1px); }

.verdict, .report {
  margin-top: 1rem;
  padding: 1rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  font-size: .95rem;
}
.verdict.ok { border-color: var(--good); }
.verdict.no { border-color: var(--bad); }
.verdict h4 { margin: 0 0 .4rem; font-size: 1.05rem; }
.verdict.ok h4 { color: var(--good); }
.verdict.no h4 { color: var(--bad); }
.verdict p { margin: .35rem 0; color: var(--dim); }

.report table { font-size: .85rem; }
.report .rate { font-size: 1.3rem; font-weight: 700; }

.downloads li { margin: .3rem 0; }

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

footer {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-size: .9rem;
}

@media (max-width: 30rem) {
  pre.grid { letter-spacing: .06em; font-size: .9rem; }
}