:root {
  --bg: #0d1117;
  --panel: #161b22;
  --panel2: #1c2330;
  --ink: #e6edf3;
  --muted: #8b949e;
  --accent: #3fb27f;
  --accent-dim: #2a7a58;
  --amber: #d4a72c;
  --line: #30363d;
  --mono: "SF Mono", ui-monospace, Menlo, Consolas, monospace;
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 16px/1.6 -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code, pre { font-family: var(--mono); }
code { background: var(--panel2); padding: 0.1em 0.35em; border-radius: 4px; font-size: 0.88em; }
pre {
  background: var(--panel); border: 1px solid var(--line); border-radius: 8px;
  padding: 1rem 1.2rem; overflow-x: auto; font-size: 0.84rem; line-height: 1.55;
}
pre code { background: none; padding: 0; }

/* nav */
nav {
  display: flex; align-items: center; gap: 1.4rem;
  padding: 0.85rem 2rem; border-bottom: 1px solid var(--line);
  background: rgba(13,17,23,0.92); position: sticky; top: 0; backdrop-filter: blur(8px);
  flex-wrap: wrap;
}
nav .brand { font-weight: 700; font-size: 1.05rem; letter-spacing: -0.01em; color: var(--ink); }
nav .brand span { color: var(--accent); }
nav a.tab { color: var(--muted); font-size: 0.92rem; }
nav a.tab.active { color: var(--ink); font-weight: 600; }
nav a.tab:hover { color: var(--ink); text-decoration: none; }
nav .spacer { flex: 1; }
nav a.acct { color: var(--muted); font-size: 0.85rem; }
nav a.acct.btn {
  border: 1px solid var(--accent-dim); color: var(--accent);
  padding: 0.3em 0.9em; border-radius: 6px;
}

.wrap { max-width: 1060px; margin: 0 auto; padding: 0 2rem 5rem; }
.banner {
  background: #2b2111; border: 1px solid #5c4a1a; color: var(--amber);
  border-radius: 8px; padding: 0.55rem 1rem; font-size: 0.85rem; margin: 1.4rem 0 0;
}

/* hero */
.hero { padding: 4.5rem 0 3rem; max-width: 780px; }
.hero h1 { font-size: 2.6rem; line-height: 1.12; letter-spacing: -0.02em; margin: 0 0 1rem; }
.hero h1 em { color: var(--accent); font-style: normal; }
.hero p.lede { font-size: 1.18rem; color: var(--muted); margin: 0 0 1.8rem; }
.cta { display: inline-block; background: var(--accent); color: #06130c; font-weight: 600;
  padding: 0.65em 1.4em; border-radius: 8px; margin-right: 0.8rem; }
.cta:hover { text-decoration: none; filter: brightness(1.08); }
.cta.ghost { background: none; border: 1px solid var(--line); color: var(--ink); }

h2 { font-size: 1.5rem; margin: 3rem 0 1rem; letter-spacing: -0.01em; }
h3 { font-size: 1.08rem; margin: 1.8rem 0 0.5rem; }
p { margin: 0.6rem 0; }
.muted { color: var(--muted); }

/* how-it-works steps */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 1rem; margin: 1.4rem 0; }
.step { background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 1.1rem 1.2rem; }
.step .n { font: 700 0.75rem var(--mono); color: var(--accent); letter-spacing: 0.1em; }
.step h4 { margin: 0.4rem 0 0.3rem; font-size: 0.98rem; }
.step p { margin: 0; font-size: 0.86rem; color: var(--muted); }

/* problem cards */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1.2rem; margin-top: 1.6rem; }
.card {
  background: var(--panel); border: 1px solid var(--line); border-radius: 12px;
  overflow: hidden; display: flex; flex-direction: column; transition: border-color 0.15s;
}
.card:hover { border-color: var(--accent-dim); }
.card .thumb {
  height: 150px; background: #f4f4f2; display: flex; align-items: center;
  justify-content: center; overflow: hidden;
}
.card .thumb img { max-height: 138px; max-width: 92%; object-fit: contain; }
.card .body { padding: 1rem 1.15rem 1.15rem; display: flex; flex-direction: column; gap: 0.5rem; flex: 1; }
.card .title { font-weight: 650; font-size: 1rem; }
.card .tagrow { display: flex; gap: 0.4rem; flex-wrap: wrap; }
.pill {
  font: 600 0.68rem var(--mono); letter-spacing: 0.04em; padding: 0.28em 0.65em;
  border-radius: 99px; background: var(--panel2); color: var(--muted);
  border: 1px solid var(--line); white-space: nowrap;
}
.pill.calc { color: var(--accent); border-color: var(--accent-dim); }
.pill.fid { color: var(--amber); border-color: #5c4a1a; }
.card table { width: 100%; border-collapse: collapse; font-size: 0.8rem; }
.card td { padding: 0.18rem 0; color: var(--muted); }
.card td:last-child { text-align: right; color: var(--ink); font-family: var(--mono); font-size: 0.78rem; }
.card .bounty {
  margin-top: auto; padding: 0.7rem 0.9rem 0.75rem; border-top: 1px solid var(--line);
  display: flex; justify-content: space-between; align-items: baseline;
  background: linear-gradient(180deg, rgba(63,178,127,0.10), rgba(63,178,127,0.03));
  margin-left: -1.15rem; margin-right: -1.15rem; margin-bottom: -1.15rem;
}
.card .bounty .usd {
  font: 800 1.7rem var(--mono); color: var(--accent);
  text-shadow: 0 0 18px rgba(63,178,127,0.35); letter-spacing: -0.02em;
}
.card .bounty .usd small { font-size: 0.65rem; font-weight: 600; color: var(--muted);
  display: block; letter-spacing: 0.09em; text-transform: uppercase; }
.card .bounty .est { font-size: 0.75rem; color: var(--muted); text-align: right; }

/* bounty stats strip */
.statstrip {
  display: flex; gap: 1rem; flex-wrap: wrap; margin: 1.6rem 0 0.4rem;
}
.stat {
  flex: 1 1 150px; background: var(--panel); border: 1px solid var(--line);
  border-radius: 10px; padding: 0.85rem 1.1rem;
}
.stat .big { font: 800 1.6rem var(--mono); color: var(--accent); letter-spacing: -0.02em; }
.stat .lbl { font-size: 0.72rem; color: var(--muted); letter-spacing: 0.08em;
  text-transform: uppercase; margin-top: 0.15rem; }
.stat.hot { border-color: var(--accent-dim); }

/* tutorials + docs */
.toc { background: var(--panel); border: 1px solid var(--line); border-radius: 10px;
  padding: 1rem 1.4rem; margin: 1.4rem 0; font-size: 0.92rem; }
.toc ol { margin: 0.4rem 0 0; padding-left: 1.2rem; }
.note { border-left: 3px solid var(--accent-dim); background: var(--panel);
  padding: 0.7rem 1rem; border-radius: 0 8px 8px 0; font-size: 0.9rem; margin: 1rem 0; }
.note.warn { border-color: var(--amber); }
.draft { font: 600 0.7rem var(--mono); color: var(--amber); letter-spacing: 0.08em;
  text-transform: uppercase; }

footer {
  border-top: 1px solid var(--line); margin-top: 4rem; padding: 1.4rem 2rem;
  color: var(--muted); font-size: 0.82rem; display: flex; gap: 1.6rem; flex-wrap: wrap;
}