/* Shared look for every challenge page: black, terminal, one green accent. */
:root { --bg:#000; --fg:#e8e8e8; --dim:#6b6b6b; --line:#1c1c1c; --accent:#00ff9c; --danger:#ff2e63; }
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  min-height: 100svh; background: var(--bg); color: var(--fg);
  font-family: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 15px; line-height: 1.6;
  background-image: repeating-linear-gradient(to bottom, transparent 0 2px, rgba(255,255,255,.025) 2px 3px);
  padding: clamp(1.5rem, 6vw, 5rem) 16px;
}
main { max-width: 760px; margin: 0 auto; }
a { color: var(--accent); }
h1 { font-family: Inter, system-ui, sans-serif; font-weight: 900; letter-spacing: -.03em; font-size: clamp(2rem, 7vw, 3.5rem); line-height: 1; margin: .5rem 0 1.5rem; }
.label { color: var(--accent); font-size: .75rem; letter-spacing: .15em; text-transform: uppercase; }
.dim { color: var(--dim); }
.err { color: var(--danger); }
.ok { color: var(--accent); }
.box { border: 1px solid var(--line); border-radius: 10px; padding: 1.25rem; margin: 1.5rem 0; background: #050505; }
pre, code { font-family: inherit; }
pre { white-space: pre-wrap; word-break: break-word; }
input, textarea, select {
  width: 100%; background: #000; color: var(--fg); border: 1px solid #2a2a2a; border-radius: 8px;
  padding: .7rem .9rem; font: inherit; margin: .35rem 0 1rem;
}
input:focus, textarea:focus { outline: none; border-color: var(--accent); }
button {
  font: inherit; cursor: pointer; background: transparent; color: var(--accent);
  border: 1px solid var(--accent); border-radius: 999px; padding: .65rem 1.3rem;
}
button:hover { background: var(--accent); color: #000; }
table { width: 100%; border-collapse: collapse; margin: 1rem 0; }
th, td { text-align: left; padding: .5rem .6rem; border-bottom: 1px solid var(--line); }
th { color: var(--dim); font-weight: 400; }