:root {
  --primary: #003f71;
  --primary-2: #0a5da0;
  --bg: #071427;
  --panel: #0b1f3a;
  --panel2: #091a31;
  --text: #e7eefc;
  --muted: #a8b3cf;
  --border: #223255;
  --brand: #66c7ff;
  --good: #34d399;
  --bad: #fb7185;
  --warn: #fbbf24;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, "Noto Sans", "Liberation Sans", sans-serif;
  background:
    radial-gradient(1100px 700px at 18% 8%, rgba(0, 63, 113, 0.85) 0%, rgba(7, 20, 39, 0.9) 45%),
    radial-gradient(900px 600px at 85% 20%, rgba(10, 93, 160, 0.35) 0%, rgba(7, 20, 39, 0) 55%),
    var(--bg);
  color: var(--text);
}

.container {
  width: min(1100px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: rgba(7, 20, 39, 0.72);
  backdrop-filter: blur(10px);
}

.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
}

.brand {
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.3px;
}

.nav a { color: var(--muted); text-decoration: none; }
.nav a:hover { color: var(--text); }

.hero { padding: 20px 0 8px; }
.hero-card {
  border: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(0, 63, 113, 0.22), rgba(11, 31, 58, 0.88));
  border-radius: 16px;
  padding: 18px;
}

.stats { display: flex; gap: 18px; margin: 12px 0 10px; }
.stat { border: 1px solid var(--border); border-radius: 12px; padding: 10px 12px; background: rgba(0,0,0,0.12); }
.stat-num { font-size: 22px; font-weight: 700; }
.stat-label { color: var(--muted); font-size: 12px; }

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  padding: 14px 0 40px;
}

@media (max-width: 980px) {
  .grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .grid { grid-template-columns: 1fr; }
}

.card {
  border: 1px solid var(--border);
  background: rgba(15, 26, 47, 0.8);
  border-radius: 16px;
  padding: 14px;
}

.card-top { display: flex; justify-content: space-between; align-items: center; }

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(0, 63, 113, 0.22);
  color: var(--brand);
  font-size: 12px;
  font-weight: 600;
}

.points { color: var(--muted); font-size: 12px; }

.card-title { margin: 12px 0 6px; font-size: 18px; }
.card-title a { color: var(--text); text-decoration: none; }
.card-title a:hover { color: var(--brand); }

.summary { color: var(--muted); margin: 0 0 12px; line-height: 1.45; }

.status-row { display: flex; justify-content: space-between; align-items: center; gap: 10px; }

.status {
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 12px;
  font-weight: 600;
}

.status.done { border-color: rgba(52, 211, 153, 0.4); background: rgba(52, 211, 153, 0.12); color: var(--good); }
.status.todo { border-color: rgba(251, 113, 133, 0.35); background: rgba(251, 113, 133, 0.08); color: var(--bad); }
.status.big { padding: 10px 12px; }

.challenge-id { color: var(--muted); font-size: 12px; }

.flag-box {
  margin-top: 12px;
  border: 1px dashed rgba(0, 63, 113, 0.65);
  border-radius: 14px;
  padding: 12px;
  background: rgba(0, 63, 113, 0.12);
}

.label { color: var(--muted); font-size: 12px; margin-bottom: 8px; }

.flag-row { display: flex; gap: 10px; }

.input {
  width: 100%;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.15);
  color: var(--text);
  outline: none;
}
.input:focus { border-color: rgba(125, 211, 252, 0.55); box-shadow: 0 0 0 3px rgba(125, 211, 252, 0.12); }

.btn {
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid rgba(102, 199, 255, 0.55);
  background: rgba(0, 63, 113, 0.35);
  color: var(--text);
  font-weight: 700;
  cursor: pointer;
}
.btn:hover { background: rgba(0, 63, 113, 0.45); }
.btn:active { transform: translateY(1px); }

.btn-secondary {
  border-color: rgba(168, 179, 207, 0.4);
  background: rgba(168, 179, 207, 0.12);
}

.links { margin-top: 10px; }
.link { color: var(--brand); text-decoration: none; font-weight: 600; font-size: 13px; }
.link:hover { text-decoration: underline; }

.flash-wrap { margin: 14px 0; display: grid; gap: 8px; }
.flash { border-radius: 12px; padding: 10px 12px; border: 1px solid var(--border); background: rgba(0,0,0,0.12); }
.flash-success { border-color: rgba(52, 211, 153, 0.4); }
.flash-error { border-color: rgba(251, 113, 133, 0.35); }

.site-footer { border-top: 1px solid var(--border); padding: 18px 0; color: var(--muted); }
.muted { color: var(--muted); }

.breadcrumbs { padding: 16px 0 0; }
.breadcrumbs a { color: var(--muted); text-decoration: none; }
.breadcrumbs a:hover { color: var(--text); }

.challenge { padding: 12px 0 40px; }
.challenge-head {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: flex-start;
  border: 1px solid var(--border);
  background: rgba(15, 26, 47, 0.8);
  border-radius: 16px;
  padding: 14px;
}

.challenge-head h1 { margin: 10px 0 6px; }

.challenge-body {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 14px;
  margin-top: 14px;
}

@media (max-width: 900px) {
  .challenge-body { grid-template-columns: 1fr; }
}

.panel {
  border: 1px solid var(--border);
  background: rgba(15, 26, 47, 0.75);
  border-radius: 16px;
  padding: 14px;
}

.panel h2 { margin: 0 0 10px; }
.panel h3 { margin: 16px 0 8px; }

.prose { color: var(--text); line-height: 1.55; }

.hint summary { cursor: pointer; color: var(--brand); font-weight: 700; margin-top: 10px; }

.sep { border: none; border-top: 1px solid var(--border); margin: 14px 0; }

.file-list { margin: 0; padding-left: 18px; }
.file-list a { color: var(--brand); text-decoration: none; }
.file-list a:hover { text-decoration: underline; }

.conn .k { display: inline-block; width: 60px; color: var(--muted); }
.conn .v { color: var(--text); }

.inline { display: inline; }