:root {
  --bg: #0f0f1a;
  --bg-card: #1a1a2e;
  --bg-card-hover: #22223a;
  --text: #e0e0e0;
  --text-dim: #999;
  --primary: #6C8CFF;
  --primary-hover: #5a7ae8;
  --danger: #F44336;
  --border: #2a2a40;
  --radius: 12px;
  --transition: 0.3s ease;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  line-height: 1.6;
}

#app {
  width: 100%;
  max-width: 640px;
  padding: 20px;
}

.container {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 40px 32px;
  border: 1px solid var(--border);
}

.page {
  display: none;
  animation: fadeIn 0.4s ease;
}

.page.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.hidden { display: none !important; }

h1, h2 {
  text-align: center;
  margin-bottom: 16px;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }

.site-title {
  text-align: center;
  font-size: 2rem;
  margin-bottom: 16px;
}

.site-subtitle {
  text-align: center;
  color: var(--primary);
  font-size: 0.95rem;
  margin-bottom: 20px;
  font-weight: 500;
}

.site-desc {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.9rem;
  margin-bottom: 28px;
  line-height: 1.7;
}

.welcome-icon {
  display: flex;
  justify-content: center;
  margin-bottom: 16px;
}

.section-desc {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.9rem;
  margin-bottom: 24px;
}

.btn-primary {
  display: block;
  width: 100%;
  max-width: 280px;
  margin: 0 auto;
  padding: 14px 32px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition), transform 0.15s;
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.info-group {
  margin-bottom: 28px;
}

.info-group label {
  display: block;
  font-size: 0.95rem;
  color: var(--text);
  margin-bottom: 10px;
  font-weight: 500;
}

.info-options {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.info-option-btn {
  padding: 10px 18px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  cursor: pointer;
  font-size: 0.9rem;
  transition: all var(--transition);
}

.info-option-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.info-option-btn.selected {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

.test-topbar {
  margin-bottom: 20px;
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 10px;
}

.progress-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 3px;
  transition: width 0.4s ease;
  width: 0%;
}

.test-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-dim);
}

.timer {
  font-weight: 600;
  color: var(--primary);
}

.progress-text {
  font-weight: 600;
}

.timer.timer-warning {
  color: var(--danger);
  animation: pulse 1s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.question-label {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 10px;
}

.question-text {
  font-size: 1.1rem;
  line-height: 1.7;
  margin-bottom: 24px;
  white-space: pre-wrap;
}

.options-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 28px;
}

.option-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition);
  text-align: left;
}

.option-btn:hover {
  border-color: var(--primary);
  background: var(--bg-card-hover);
}

.option-btn.selected {
  border-color: var(--primary);
  background: rgba(108, 140, 255, 0.15);
}

.test-nav {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

.btn-nav {
  flex: 1;
  padding: 12px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-nav:hover:not(:disabled) {
  border-color: var(--primary);
  color: var(--primary);
}

.btn-nav:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-link {
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 0.85rem;
  cursor: pointer;
  padding: 8px;
  text-decoration: underline;
  transition: color var(--transition);
}

.btn-link:hover {
  color: var(--danger);
}

.result-title {
  margin-bottom: 24px;
}

.iq-display {
  text-align: center;
  margin-bottom: 12px;
}

.iq-number {
  font-size: 4.5rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: 2px;
}

.iq-label {
  font-size: 1.2rem;
  color: var(--text-dim);
  margin-left: 8px;
  font-weight: 600;
}

.iq-level {
  text-align: center;
  display: inline-block;
  margin: 0 auto 32px;
  padding: 8px 24px;
  border-radius: 20px;
  color: #fff;
  font-size: 0.95rem;
  font-weight: 600;
}

body:has(#section-result.active) #iq-level {
  display: block;
  width: fit-content;
  margin: 0 auto 32px;
}

.radar-container {
  display: flex;
  justify-content: center;
  margin-bottom: 28px;
}

.radar-container canvas {
  max-width: 100%;
  height: auto;
}

.dimension-breakdown {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 28px;
}

.dim-item {
  background: var(--bg);
  border-radius: 8px;
  padding: 16px;
}

.dim-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 8px;
  font-size: 0.9rem;
}

.dim-name {
  font-weight: 600;
}

.dim-score {
  color: var(--text-dim);
  font-size: 0.85rem;
}

.dim-bar-bg {
  width: 100%;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 8px;
}

.dim-bar-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 3px;
  transition: width 0.8s ease;
}

.dim-desc {
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.5;
}

.site-footer {
  text-align: center;
  padding: 24px 16px;
  font-size: 0.8rem;
  color: var(--text-dim);
  border-top: 1px solid var(--border);
  margin-top: 20px;
}

@media (max-width: 480px) {
  #app { padding: 12px; }
  .container { padding: 24px 16px; }
  h1 { font-size: 1.6rem; }
  .iq-number { font-size: 3.5rem; }
  .option-btn { padding: 12px 14px; }
}