:root {
  --bg: #0d1117;
  --bg2: #161b22;
  --line: #21262d;
  --fg: #c9d1d9;
  --fg-dim: #8b949e;
  --accent: #58a6ff;
  --green: #3fb950;
  --red: #f85149;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans",
        "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 880px; margin: 0 auto; padding: 0 22px; }

/* topbar */
.topbar {
  position: sticky; top: 0; z-index: 10;
  background: rgba(13, 17, 23, .88);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.topbar .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 58px; gap: 16px;
}
.brand {
  color: var(--fg); text-decoration: none;
  font-weight: 700; letter-spacing: .3px; font-size: 17px;
}
.brand .dim { color: var(--fg-dim); font-weight: 500; }
.brand .dot {
  display: inline-block; width: 8px; height: 8px; border-radius: 50%;
  background: var(--green); margin-right: 8px; vertical-align: middle;
}
.topbar nav { display: flex; gap: 18px; flex-wrap: wrap; }
.topbar nav a {
  color: var(--fg-dim); text-decoration: none; font-size: 14px;
}
.topbar nav a:hover { color: var(--accent); }

/* hero */
.hero { padding: 56px 0 8px; }
h1 {
  font-size: 40px; line-height: 1.2; margin: 0 0 16px;
  letter-spacing: -0.5px;
}
.lead { font-size: 18px; color: var(--fg-dim); max-width: 660px; margin: 0; }

.stats {
  display: flex; gap: 40px; margin: 30px 0 0;
  padding: 18px 0; border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.stats div { display: flex; flex-direction: column; }
.stats strong { font-size: 22px; color: var(--accent); }
.stats span { font-size: 13px; color: var(--fg-dim); }

/* sections */
section { padding: 34px 0; border-bottom: 1px solid var(--line); }
section:last-of-type { border-bottom: none; }
h2 {
  font-size: 21px; margin: 0 0 16px; letter-spacing: -0.2px;
}
h3 { font-size: 15px; margin: 0 0 8px; }
p { margin: 0 0 14px; }
.muted { color: var(--fg-dim); font-size: 14px; }

code {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: .88em;
  background: var(--bg2);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 1px 5px;
}

/* cards */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 22px; }
.card {
  background: var(--bg2);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
}
.card p { margin: 0; font-size: 14px; color: var(--fg-dim); }
.card h3 { color: var(--fg); }

/* panel */
.panel {
  background: var(--bg2);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 22px;
  margin: 30px 0;
}
.panel h2 { margin-top: 0; }

.controls {
  display: flex; align-items: flex-end; gap: 14px; flex-wrap: wrap;
  margin: 16px 0;
}
.controls label {
  display: flex; flex-direction: column; gap: 6px;
  font-size: 12px; color: var(--fg-dim);
}
select, input[type=number] {
  background: var(--bg);
  color: var(--fg);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 7px 10px;
  font-size: 14px;
  font-family: inherit;
}
input[type=number] { width: 96px; }

button {
  background: #238636;
  color: #fff;
  border: 1px solid rgba(240,246,252,.1);
  border-radius: 6px;
  padding: 8px 18px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
}
button:hover { background: #2ea043; }
button:active { transform: translateY(1px); }

.output {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px 16px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px;
  color: var(--green);
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
  margin: 0 0 6px;
  min-height: 48px;
}

.badge {
  display: inline-block;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 6px 14px;
  font-family: ui-monospace, monospace;
  font-size: 14px;
  color: var(--accent);
}

/* table */
.tablewrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { text-align: left; padding: 9px 12px; border-bottom: 1px solid var(--line); }
th { color: var(--fg-dim); font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: .4px; }
td code { background: transparent; border: none; padding: 0; }
.yes { color: var(--green); }
.no { color: var(--red); }

/* code block */
.code {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px 18px;
  overflow-x: auto;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px;
  line-height: 1.65;
}
.code .c { color: var(--fg-dim); }
.code .k { color: #ff7b72; }
.code .f { color: #d2a8ff; }
.code .n { color: #79c0ff; }

/* notes */
.notes { margin: 0; padding-left: 20px; }
.notes li { margin-bottom: 12px; color: var(--fg-dim); font-size: 15px; }
.notes li strong { color: var(--fg); }

/* footer */
footer {
  border-top: 1px solid var(--line);
  padding: 26px 0;
  font-size: 13px;
  color: var(--fg-dim);
}
footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
footer .dim { color: #6e7681; }

@media (max-width: 720px) {
  h1 { font-size: 30px; }
  .cards { grid-template-columns: 1fr; }
  .stats { gap: 26px; }
  .topbar nav { display: none; }
}