:root {
  --bg: #0f172a;
  --panel: #1e293b;
  --panel-2: #273449;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --good: #22c55e;
  --bad: #ef4444;
  --border: #334155;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
}

nav {
  display: flex;
  gap: 1rem;
  align-items: center;
  padding: 0.9rem 1.5rem;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

nav .brand {
  font-weight: 700;
  font-size: 1.1rem;
  margin-right: auto;
  color: var(--accent);
}

nav a {
  color: var(--text);
  text-decoration: none;
  padding: 0.4rem 0.8rem;
  border-radius: 6px;
}

nav a:hover, nav a.active {
  background: var(--panel-2);
}

main {
  max-width: 900px;
  margin: 0 auto;
  padding: 1.5rem;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: end;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

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

select, input, textarea, button {
  font-family: inherit;
  font-size: 0.95rem;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.5rem 0.7rem;
}

textarea {
  resize: vertical;
  min-height: 70px;
}

button {
  cursor: pointer;
  background: var(--accent);
  color: #04202f;
  font-weight: 600;
  border: none;
}

button:hover { filter: brightness(1.08); }

button.secondary {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
}

button.danger {
  background: var(--bad);
  color: white;
}

.meta-row {
  display: flex;
  gap: 0.75rem;
  color: var(--muted);
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
}

.question-text {
  font-size: 1.05rem;
  line-height: 1.5;
  margin-bottom: 1rem;
  white-space: pre-wrap;
}

.options { display: flex; flex-direction: column; gap: 0.5rem; }

.option-btn {
  text-align: left;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.7rem 0.9rem;
  border-radius: 8px;
  font-weight: 400;
}

.option-btn.correct { border-color: var(--good); background: #14532d; }
.option-btn.incorrect { border-color: var(--bad); background: #450a0a; }
.option-btn:disabled { cursor: default; opacity: 0.9; }

.nav-buttons { display: flex; justify-content: space-between; margin-top: 1rem; }

.explanation {
  margin-top: 1rem;
  padding: 0.8rem;
  background: var(--panel-2);
  border-radius: 8px;
  border-left: 3px solid var(--accent);
  font-size: 0.9rem;
}

.score-badge {
  font-size: 0.85rem;
  color: var(--muted);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

th, td {
  text-align: left;
  padding: 0.5rem;
  border-bottom: 1px solid var(--border);
}

th { color: var(--muted); font-weight: 600; }

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.form-grid .full { grid-column: 1 / -1; }

.empty-state { color: var(--muted); text-align: center; padding: 2rem; }

.actions-cell { display: flex; gap: 0.4rem; }

.actions-cell button { padding: 0.3rem 0.6rem; font-size: 0.8rem; }