:root {
  color-scheme: light dark;
  --bg: #0b0d12;
  --surface: #12151d;
  --surface-2: #171b25;
  --border: #232732;
  --fg: #f2f3f5;
  --muted: #9aa0ab;
  --accent: #6ea8fe;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
}

body {
  background: radial-gradient(circle at 50% 0%, #151922 0%, var(--bg) 55%);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

a { color: inherit; }

/* Top nav */
.topnav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(18, 21, 29, 0.7);
  backdrop-filter: blur(6px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.topnav .brand {
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
  font-size: 1.05rem;
}

.topnav nav {
  display: flex;
  gap: 0.25rem;
}

.topnav nav a, .topnav nav .dropdown > summary {
  display: inline-flex;
  padding: 0.5rem 0.9rem;
  border-radius: 8px;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  list-style: none;
}

.topnav nav a:hover, .topnav nav .dropdown > summary:hover {
  color: var(--fg);
  background: var(--surface);
}

.topnav nav a.active {
  color: var(--accent);
  background: rgba(110, 168, 254, 0.12);
}

.dropdown { position: relative; }
.dropdown > summary::-webkit-details-marker { display: none; }
.dropdown[open] > summary { color: var(--fg); background: var(--surface); }

.dropdown-menu {
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.4rem;
  min-width: 180px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.35);
}

.dropdown-menu a {
  display: block;
  padding: 0.55rem 0.75rem;
  border-radius: 6px;
  font-size: 0.88rem;
  color: var(--fg);
}

.dropdown-menu a:hover { background: var(--surface-2); }

/* Hero (home) */
.hero {
  max-width: 900px;
  margin: 0 auto;
  padding: 5rem 1.5rem 4rem;
  text-align: center;
}

.hero .status {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  background: rgba(110, 168, 254, 0.12);
  border: 1px solid rgba(110, 168, 254, 0.35);
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 500;
  margin-bottom: 1.25rem;
}

.dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 650;
  letter-spacing: -0.02em;
  margin: 0 0 0.75rem;
}

.hero p {
  color: var(--muted);
  max-width: 46ch;
  margin: 0 auto 2rem;
  line-height: 1.6;
  font-size: 1.05rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 0.65rem 1.3rem;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--border);
  cursor: pointer;
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #0b0d12;
}

.btn-primary:hover { opacity: 0.9; }

.btn-secondary {
  background: transparent;
  color: var(--fg);
}

.btn-secondary:hover { background: var(--surface); }

.tpt-note {
  margin-top: 1.75rem;
  font-size: 0.85rem;
  color: var(--muted);
}

.page-narrow {
  max-width: 680px;
}

.page-narrow p {
  color: var(--muted);
  line-height: 1.7;
  margin: 0 0 1.1rem;
}

/* Request form */
.req-form { margin-top: 2rem; }

.req-label {
  display: block;
  font-weight: 600;
  font-size: 0.92rem;
  margin: 1.5rem 0 0.25rem;
}

.req-form > .req-label:first-child { margin-top: 0; }

.req-hint {
  color: var(--muted);
  font-size: 0.82rem;
  margin: 0 0 0.5rem;
  line-height: 1.5;
}

.req-required { color: #ff8080; }

.req-input {
  width: 100%;
  padding: 0.6rem 0.75rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--fg);
  font-size: 0.9rem;
  font-family: inherit;
  resize: vertical;
}

.req-input:focus { outline: 1px solid var(--accent); }

.req-checkboxes {
  display: grid;
  gap: 0.5rem;
}

.req-checkboxes label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.88rem;
  color: var(--fg);
  cursor: pointer;
}

/* Page container */
.page {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

.page h1 {
  font-size: 1.75rem;
  margin: 0 0 0.5rem;
}

.page > p.lede {
  color: var(--muted);
  margin: 0 0 2rem;
}

/* Level select cards (Simulations landing) */
.level-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.level-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.75rem;
  text-decoration: none;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.level-card:hover {
  border-color: rgba(110, 168, 254, 0.4);
  transform: translateY(-2px);
}

.level-card h2 {
  margin: 0 0 0.4rem;
  font-size: 1.2rem;
}

.level-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

/* Unit browser layout */
.browser {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 1.75rem;
  align-items: start;
}

.sidebar {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.6rem;
  position: sticky;
  top: 80px;
}

.sidebar a {
  display: block;
  padding: 0.55rem 0.75rem;
  border-radius: 7px;
  font-size: 0.88rem;
  text-decoration: none;
  color: var(--muted);
  margin-bottom: 2px;
}

.sidebar a:hover { background: var(--surface-2); color: var(--fg); }

.sidebar a.active {
  background: rgba(110, 168, 254, 0.14);
  color: var(--accent);
  font-weight: 600;
}

/* Data table */
table.sim-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}

table.sim-table th {
  text-align: left;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border);
}

table.sim-table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
  font-size: 0.9rem;
}

table.sim-table tr:last-child td { border-bottom: none; }

.sim-thumb {
  width: 96px;
  height: 60px;
  object-fit: cover;
  border-radius: 6px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  display: block;
}

.sim-title { font-weight: 600; margin-bottom: 0.15rem; }
.sim-desc { color: var(--muted); font-size: 0.85rem; }

.view-btn {
  display: inline-flex;
  padding: 0.4rem 0.85rem;
  border-radius: 6px;
  background: rgba(110, 168, 254, 0.12);
  border: 1px solid rgba(110, 168, 254, 0.35);
  color: var(--accent);
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 500;
  white-space: nowrap;
}

.view-btn:hover { background: rgba(110, 168, 254, 0.2); }

.empty-state {
  color: var(--muted);
  padding: 3rem 1rem;
  text-align: center;
  border: 1px dashed var(--border);
  border-radius: 10px;
}

footer {
  text-align: center;
  color: var(--muted);
  font-size: 0.8rem;
  padding: 0 1.5rem 3rem;
}