:root {
  --bg: #0d1117;
  --surface: #161b22;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent: #FF9900;
  --green: #3fb950;
  --red: #f85149;
  --btn-bg: #21262d;
  --btn-hover: #30363d;
  --radius: 8px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

header {
  text-align: center;
  margin-bottom: 2rem;
}

header h1 {
  font-size: 1.5rem;
  color: var(--accent);
  margin-bottom: 0.25rem;
}

header p {
  color: var(--text-muted);
  font-size: 0.875rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.card h2 {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}

label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

select, input[type="number"] {
  width: 100%;
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  padding: 0.6rem 0.75rem;
  font-size: 0.9rem;
  margin-bottom: 1rem;
  appearance: none;
  -webkit-appearance: none;
}

select:focus, input:focus {
  outline: none;
  border-color: var(--accent);
}

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

.form-row-narrow {
  grid-template-columns: 1fr;
  max-width: 50%;
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: opacity 0.1s, background 0.1s;
}

.btn-primary {
  background: var(--accent);
  color: #000;
  width: 100%;
  text-align: center;
}

.btn-primary:hover { opacity: 0.85; }

.btn-secondary {
  background: var(--btn-bg);
  color: var(--text);
  border: 1px solid var(--border);
}

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

.btn-group {
  display: flex;
  gap: 0.75rem;
  margin-top: 1rem;
}

.btn-group .btn { flex: 1; text-align: center; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

th {
  text-align: left;
  color: var(--text-muted);
  font-weight: 500;
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--border);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

td {
  padding: 0.65rem 0.75rem;
  border-bottom: 1px solid var(--border);
}

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

.score-good { color: var(--green); font-weight: 600; }
.score-mid  { color: var(--accent); font-weight: 600; }
.score-bad  { color: var(--red); font-weight: 600; }

.progress-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: right;
  margin-bottom: 0.4rem;
}

.progress-bar-outer {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  margin-bottom: 1.5rem;
}

.progress-bar-inner {
  height: 4px;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.3s;
}

.domain-badge {
  display: inline-block;
  font-size: 0.7rem;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 4px;
  padding: 0.15rem 0.5rem;
  margin-bottom: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.question-text {
  font-size: 1.05rem;
  line-height: 1.65;
  margin-bottom: 1.5rem;
}

.options {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.option-btn {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  padding: 0.85rem 1rem;
  cursor: pointer;
  text-align: left;
  font-size: 0.9rem;
  line-height: 1.5;
  transition: border-color 0.1s, background 0.1s;
  width: 100%;
}

.option-btn:hover:not(:disabled) {
  border-color: var(--accent);
  background: var(--btn-hover);
}

.option-btn:disabled { cursor: default; }

.option-btn.correct {
  border-color: var(--green);
  background: rgba(63, 185, 80, 0.1);
}

.option-btn.incorrect {
  border-color: var(--red);
  background: rgba(248, 81, 73, 0.1);
}

.option-label {
  font-weight: 700;
  color: var(--text-muted);
  min-width: 1.2rem;
  flex-shrink: 0;
}

.explanation {
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  background: var(--btn-bg);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 0.875rem;
  line-height: 1.65;
  color: var(--text-muted);
  display: none;
}

.explanation.visible { display: block; }

.next-row {
  margin-top: 1.25rem;
  text-align: right;
  display: none;
}

.next-row.visible { display: block; }

.next-row .btn { width: auto; }

.result-score {
  text-align: center;
  padding: 2rem 0 1.5rem;
}

.score-number {
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1;
}

.score-detail {
  color: var(--text-muted);
  margin-top: 0.5rem;
  font-size: 0.9rem;
}

.stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 1rem;
  margin-bottom: 0.5rem;
}

.stat-box {
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  text-align: center;
}

.stat-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 2rem;
  font-size: 0.875rem;
}