:root {
  --bg: #07130d;
  --card: #0d1b13;
  --card-2: #112419;
  --green: #5fffb0;
  --green-soft: #90f2c5;
  --text: #d9fce8;
  --muted: #9fbdab;
  --border: #1f4333;
  --danger: #ff7a7a;
  --warning: #ffc857;
  --success: #73f7a7;
  --shadow: rgba(0, 0, 0, 0.25);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: radial-gradient(circle at top, #0f2318 0%, var(--bg) 45%, #050b08 100%);
  color: var(--text);
}

.landing-page, .dashboard {
  min-height: 100vh;
}

.ghost-link {
  display: inline-block;
  margin-top: 18px;
  margin-right: 12px;
  text-decoration: none;
  color: var(--green-soft);
  border: 1px solid var(--border);
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(95, 255, 176, 0.05);
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 60px;
  border-bottom: 1px solid var(--border);
  background: rgba(10, 21, 16, 0.75);
}

.brand {
  font-weight: bold;
  letter-spacing: 0.08em;
  color: var(--green);
}

.nav-links { display: flex; gap: 18px; }
.nav-links a {
  color: var(--text);
  text-decoration: none;
  opacity: 0.8;
}

.hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 20px 30px;
  display: grid;
  grid-template-columns: 1.4fr 0.9fr;
  gap: 28px;
}

.intro, .login-box, .section-card, .card, .challenge-item, .simulator-panel, .challenge-panel {
  background: rgba(13, 27, 19, 0.9);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 18px 40px var(--shadow);
}

.intro {
  padding: 34px;
}

.badge {
  display: inline-block;
  padding: 8px 12px;
  border: 1px solid var(--green);
  border-radius: 999px;
  color: var(--green-soft);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1, h2, h3 {
  margin-top: 0;
}

.hero h1 {
  font-size: clamp(2.3rem, 5vw, 4rem);
  margin: 18px 0 14px;
}

.hero p {
  color: var(--muted);
  line-height: 1.7;
}

.quick-stats {
  display: flex;
  gap: 18px;
  margin-top: 24px;
  flex-wrap: wrap;
}

.quick-stats div {
  background: #10261c;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 18px;
  min-width: 120px;
}

.quick-stats strong {
  display: block;
  font-size: 1.5rem;
  color: var(--green);
}

.quick-stats span {
  color: var(--muted);
  font-size: 0.82rem;
}

.login-box {
  padding: 28px 24px;
}

.login-box form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  color: var(--muted);
}

input, button {
  font: inherit;
}

input {
  background: #071812;
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 10px;
  padding: 12px 14px;
}

button {
  background: linear-gradient(135deg, var(--green), #1adf73);
  color: #032612;
  border: none;
  font-weight: bold;
  padding: 12px 16px;
  border-radius: 10px;
  cursor: pointer;
}

.alert {
  border-radius: 10px;
  padding: 12px 14px;
  margin: 12px 0;
  font-size: 0.95rem;
}

.alert.error { background: rgba(255, 122, 122, 0.1); border: 1px solid var(--danger); color: #ffb3b3; }
.alert.success { background: rgba(115, 247, 167, 0.08); border: 1px solid var(--success); color: #c6ffd9; }
.alert.warning { background: rgba(255, 200, 87, 0.08); border: 1px solid var(--warning); color: #ffe4a2; }

.tiny { font-size: 0.8rem; color: var(--muted); }

.section-card {
  max-width: 1200px;
  margin: 20px auto 0;
  padding: 28px 24px;
}

.grid.three {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.grid.three article {
  background: #0b1d15;
  border: 1px solid var(--border);
  padding: 18px;
  border-radius: 12px;
}

.lab-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.lab-item {
  background: #0b1c15;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
}

.pill {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 5px 8px;
  border-radius: 999px;
  background: rgba(95, 255, 176, 0.12);
  border: 1px solid var(--green);
  color: var(--green-soft);
}

.pill.alt {
  background: rgba(58, 120, 255, 0.08);
  border-color: #6ea8ff;
  color: #b8d1ff;
}

.footer {
  text-align: center;
  color: var(--muted);
  padding: 30px 20px 50px;
}

.dashboard-shell {
  display: grid;
  grid-template-columns: 220px 1fr;
  min-height: 100vh;
}

.sidebar {
  background: rgba(7, 17, 12, 0.9);
  border-right: 1px solid var(--border);
  padding: 24px 16px;
}

.sidebar nav {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 24px;
}

.sidebar nav a {
  color: var(--text);
  text-decoration: none;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid transparent;
}

.sidebar nav a:hover {
  border-color: var(--border);
  background: rgba(95, 255, 176, 0.06);
}

.content {
  padding: 30px 24px;
}

.topline {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.75rem;
}

.role-pill {
  background: rgba(95, 255, 176, 0.1);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 8px 12px;
  color: var(--green-soft);
  text-transform: capitalize;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
  margin-bottom: 26px;
}

.card {
  padding: 18px;
}

.stats-row {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin: 18px 0;
}

.mini-stat {
  background: rgba(13, 27, 19, 0.9);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 18px;
  min-width: 120px;
}

.mini-stat span {
  display: block;
  color: var(--muted);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.mini-stat strong {
  color: var(--green);
  font-size: 1.7rem;
}

.challenge-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.category-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.filter-pill {
  display: inline-block;
  text-decoration: none;
  color: var(--muted);
  padding: 8px 12px;
  background: rgba(9, 19, 13, 0.9);
  border: 1px solid var(--border);
  border-radius: 999px;
}

.filter-pill.active {
  color: var(--green-soft);
  border-color: var(--green);
  background: rgba(95, 255, 176, 0.08);
}

.challenge-panel {
  background: rgba(13, 27, 19, 0.9);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px;
}

.challenge-item {
  margin-top: 16px;
  padding: 18px;
}

.challenge-meta {
  margin-bottom: 10px;
}

.category-badge {
  display: inline-block;
  border-radius: 999px;
  background: rgba(94, 255, 176, 0.08);
  color: var(--green-soft);
  border: 1px solid var(--border);
  padding: 6px 10px;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.hint {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.9rem;
}

.leaderboard-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 18px;
}

.leaderboard-table th,
.leaderboard-table td {
  border: 1px solid var(--border);
  padding: 12px 14px;
  text-align: left;
}

.leaderboard-table th {
  color: var(--green-soft);
  background: rgba(95, 255, 176, 0.06);
}

.admin-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin-top: 20px;
}

.admin-card {
  background: rgba(9, 19, 13, 0.8);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
}

.admin-card span {
  color: var(--muted);
  display: block;
  margin-bottom: 8px;
}

.admin-card strong {
  font-size: 2rem;
  color: var(--green);
}

.simulator-layout {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 20px;
}

.simulator-panel {
  padding: 20px;
}

.simulator-panel pre {
  background: #040b08;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
  color: var(--green-soft);
  overflow-x: auto;
}

@media (max-width: 860px) {
  .hero {
    grid-template-columns: 1fr;
  }

  .dashboard-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .topbar {
    padding: 18px 20px;
    flex-direction: column;
    gap: 12px;
  }

  .grid.three {
    grid-template-columns: 1fr;
  }

  .challenge-item form {
    flex-direction: column;
  }

  .simulator-layout {
    grid-template-columns: 1fr;
  }
}