:root {
  --bg: #0f1115;
  --surface: #171b22;
  --border: #2a2f3a;
  --text: #e4e6eb;
  --muted: #8b929e;
  --accent: #6366f1;
  --ok: #10b981;
  --bad: #ef4444;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, "Pretendard", "Segoe UI", Roboto, sans-serif;
  background: var(--bg); color: var(--text);
  min-height: 100vh; display: flex; flex-direction: column;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.topbar {
  display: flex; justify-content: space-between; align-items: center;
  padding: 0.75rem 1.5rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.topbar .brand a { color: var(--text); font-weight: 700; font-size: 1.1rem; }
.topbar nav { display: flex; gap: 1rem; align-items: center; }
.user { color: var(--muted); font-size: 0.9rem; }

main {
  flex: 1;
  max-width: 1200px; width: 100%;
  margin: 0 auto; padding: 2rem 1.5rem;
}

footer {
  text-align: center; padding: 1rem;
  color: var(--muted); border-top: 1px solid var(--border);
}

h1 { margin-top: 0; }

.btn {
  display: inline-block; padding: 0.5rem 1rem;
  background: var(--surface); color: var(--text);
  border: 1px solid var(--border); border-radius: 6px;
  cursor: pointer; font-size: 0.95rem;
}
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); color: white; border-color: var(--accent); }

table { width: 100%; border-collapse: collapse; }
th, td { padding: 0.75rem 1rem; border-bottom: 1px solid var(--border); text-align: left; }
th { background: var(--surface); color: var(--muted); font-weight: 600; font-size: 0.85rem; text-transform: uppercase; }

.badge {
  display: inline-block; padding: 0.1rem 0.5rem;
  border-radius: 4px; font-size: 0.75rem; font-weight: 600;
}
.badge-python { background: #2d4a67; color: #9dd0f5; }
.badge-infra { background: #4a3c1f; color: #f5d48a; }

.prob-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem;
}
@media (max-width: 900px) { .prob-grid { grid-template-columns: 1fr; } }

.prob-desc, .prob-editor {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 8px; padding: 1.25rem;
}
.prob-desc pre { background: #0b0d12; padding: 0.75rem; border-radius: 6px; overflow-x: auto; }
.prob-desc code { background: #0b0d12; padding: 0.1rem 0.3rem; border-radius: 4px; }

.prob-editor .CodeMirror { height: 400px; border-radius: 6px; font-size: 14px; }
.prob-editor form button { margin-top: 0.75rem; }

.result {
  margin-top: 1rem; padding: 1rem; border-radius: 6px;
  border: 1px solid var(--border);
}
.result.ok { border-color: var(--ok); background: rgba(16,185,129,0.08); }
.result.bad { border-color: var(--bad); background: rgba(239,68,68,0.08); }
.result pre { background: #0b0d12; padding: 0.75rem; border-radius: 4px; white-space: pre-wrap; font-size: 0.85rem; }
.pending { color: var(--muted); }

.auth-box {
  max-width: 400px; margin: 3rem auto;
  padding: 2rem;
  background: var(--surface); border: 1px solid var(--border); border-radius: 8px;
}
.auth-box label { display: block; margin-bottom: 1rem; }
.auth-box input {
  display: block; width: 100%; padding: 0.5rem;
  background: var(--bg); color: var(--text);
  border: 1px solid var(--border); border-radius: 4px; margin-top: 0.25rem;
}
.auth-box button { width: 100%; padding: 0.65rem; }

.hint { color: var(--muted); font-size: 0.9rem; }
.ok, .result.ok h2 { color: var(--ok); }
.bad, .result.bad h2 { color: var(--bad); }