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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 30px 20px;
}

#app { width: 100%; max-width: 680px; min-height: 480px; }

.page { display: none; animation: fadeIn 0.35s ease; }
.page.active { display: block; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.card {
  background: white;
  border-radius: 20px;
  padding: 32px 28px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 13px 36px;
  border: none;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.btn:disabled { opacity: 0.35; cursor: not-allowed; }

.btn-primary {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #fff;
  box-shadow: 0 4px 15px rgba(102,126,234,0.35);
}
.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(102,126,234,0.45);
}

.btn-secondary {
  background: #f0f0f5;
  color: #555;
}
.btn-secondary:hover:not(:disabled) { background: #e5e5ea; }

/* ===== Language Selector ===== */
.lang-selector {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 8px;
}
.lang-selector select {
  padding: 6px 12px;
  border: 1px solid #d0d0e0;
  border-radius: 8px;
  font-size: 13px;
  background: #f7f8fc;
  color: #444;
  cursor: pointer;
  outline: none;
  transition: border-color 0.2s;
  max-width: 160px;
}
.lang-selector select:hover,
.lang-selector select:focus {
  border-color: #667eea;
}

/* ===== Selector ===== */
.selector-card { padding: 36px 32px; position: relative; }
.selector-header { text-align: center; margin-bottom: 28px; }
.selector-logo { font-size: 52px; margin-bottom: 8px; }
.selector-header h1 { font-size: 26px; font-weight: 700; color: #1a1a2e; }
.selector-subtitle { color: #888; font-size: 14px; margin-top: 6px; }

.test-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

.test-card {
  position: relative;
  border-radius: 16px;
  overflow: hidden;
  cursor: pointer;
  transition: transform 0.25s, box-shadow 0.25s;
  min-height: 180px;
}
.test-card:hover { transform: translateY(-4px); box-shadow: 0 12px 28px rgba(0,0,0,0.2); }
.test-card:focus-visible { outline: 3px solid #667eea; outline-offset: 2px; }

.test-card-bg {
  position: absolute; inset: 0;
  opacity: 0.92;
}

.test-card-content {
  position: relative;
  z-index: 1;
  padding: 20px 18px;
  color: #fff;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.test-icon { font-size: 32px; display: block; margin-bottom: 6px; }
.test-card-content h3 { font-size: 16px; font-weight: 700; margin-bottom: 4px; }
.test-desc { font-size: 12px; line-height: 1.5; opacity: 0.85; margin-bottom: 8px; flex:1; }
.test-meta { font-size: 12px; opacity: 0.7; display: flex; align-items: center; gap: 4px; }
.meta-dot { opacity: 0.5; }

/* ===== Reminder ===== */
.reminder-card { text-align: left; }
.reminder-icon { text-align: center; font-size: 44px; margin-bottom: 10px; }
.reminder-card h2 { text-align: center; font-size: 20px; color: #1a1a2e; margin-bottom: 16px; }

.reminder-list { list-style: none; margin-bottom: 22px; }
.reminder-list li {
  padding: 8px 0 8px 24px;
  position: relative;
  font-size: 14px;
  color: #444;
  line-height: 1.5;
  border-bottom: 1px solid #f0f0f5;
}
.reminder-list li:last-child { border-bottom: none; }
.reminder-list li::before {
  content: "•";
  position: absolute; left: 4px;
  color: #667eea; font-weight: bold; font-size: 18px;
}

/* ===== Quiz ===== */
.quiz-card { padding: 24px 24px; }
.quiz-header { margin-bottom: 18px; }

.quiz-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.btn-home {
  background: #f0f0f5;
  border: none;
  font-size: 12px;
  font-weight: 600;
  color: #666;
  cursor: pointer;
  padding: 5px 12px;
  border-radius: 8px;
  transition: all 0.2s;
  line-height: 1.3;
  margin-left: 6px;
  white-space: nowrap;
}
.btn-home:hover { background: #e0e0ea; color: #444; }
.btn-home:active { background: #d0d0dd; }

.badge {
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  background: #eef0ff;
  color: #667eea;
}

.timer {
  font-size: 16px;
  font-weight: 700;
  color: #333;
  font-variant-numeric: tabular-nums;
  padding: 4px 14px;
  border-radius: 8px;
  background: #f0f0f5;
  transition: all 0.3s;
}
.timer.warning { color: #e67e22; background: #fef5e7; animation: pulse 1s infinite; }
.timer.danger { color: #e74c3c; background: #fdedec; animation: pulse 0.5s infinite; }

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.progress-bar { height: 5px; background: #eef0ff; border-radius: 3px; overflow: hidden; }
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #667eea, #764ba2);
  border-radius: 3px;
  transition: width 0.4s ease;
  width: 0%;
}

.question-text {
  font-size: 17px;
  font-weight: 600;
  color: #1a1a2e;
  line-height: 1.7;
  margin-bottom: 4px;
  min-height: 50px;
}

.options { display: flex; flex-direction: column; gap: 8px; }

.option {
  display: block; width: 100%;
  padding: 12px 16px;
  border: 2px solid #e8e8f0;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.2s;
  font-size: 15px;
  color: #333;
  line-height: 1.5;
  text-align: left;
  background: white;
}
.option:hover { border-color: #667eea; background: #f8f8ff; }
.option.selected { border-color: #667eea; background: #eef0ff; color: #667eea; font-weight: 600; }

.quiz-footer {
  display: flex;
  align-items: center;
  margin-top: 18px;
  gap: 12px;
}
.quiz-footer .btn { flex-shrink: 0; }
.q-num { flex: 1; text-align: center; font-size: 14px; color: #999; }

/* ===== Timeout ===== */
.timeout-icon { font-size: 60px; text-align: center; margin-bottom: 14px; }
.timeout-text { text-align: center; color: #666; font-size: 15px; margin-bottom: 22px; }

/* ===== Result ===== */
.result-card { text-align: center; }
.result-card h2 { font-size: 22px; color: #1a1a2e; margin-bottom: 18px; }

.result-main { margin-bottom: 22px; }
.result-icon-big { font-size: 52px; margin-bottom: 4px; }
.result-main h3 { font-size: 17px; color: #444; margin-bottom: 10px; font-weight: 600; }

.score-ring {
  position: relative;
  width: 130px; height: 130px;
  margin: 0 auto 10px;
}
.score-ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.ring-bg { fill: none; stroke: #e8e8f0; stroke-width: 8; }
.ring-fill {
  fill: none;
  stroke: url(#iqGradient);
  stroke-width: 8;
  stroke-linecap: round;
  stroke-dasharray: 326.73;
  stroke-dashoffset: 326.73;
  transition: stroke-dashoffset 1.5s ease;
}
.score-value {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  font-size: 36px; font-weight: 700;
  color: #1a1a2e;
}
.score-label { font-size: 18px; font-weight: 700; color: #667eea; margin-bottom: 4px; }
.score-desc { font-size: 13px; color: #888; line-height: 1.6; max-width: 380px; margin: 0 auto; }

/* Index scores */
.index-scores {
  text-align: left;
  margin-bottom: 22px;
  padding: 18px;
  background: #f8f9ff;
  border-radius: 16px;
}
.index-scores h3 { font-size: 14px; color: #333; margin-bottom: 14px; text-align: center; }
.index-bar-group { display: flex; flex-direction: column; gap: 10px; }

.index-bar {
  display: flex;
  align-items: center;
  gap: 8px;
}
.index-label {
  width: 120px;
  font-size: 13px;
  color: #555;
  flex-shrink: 0;
  text-align: right;
}
.index-label small { color: #999; font-size: 11px; }

.bar-track {
  flex: 1;
  height: 16px;
  background: #e8e8f0;
  border-radius: 8px;
  overflow: hidden;
}
.bar-fill {
  height: 100%;
  border-radius: 8px;
  transition: width 1.2s ease;
  background: linear-gradient(90deg, #667eea, #764ba2);
}
.index-score {
  width: 32px;
  font-size: 14px;
  font-weight: 700;
  color: #1a1a2e;
  flex-shrink: 0;
}

/* Detail list */
.result-detail { text-align: left; margin-bottom: 18px; }
.result-detail h4 { font-size: 14px; color: #333; margin-bottom: 8px; }

.detail-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 5px 0;
  border-bottom: 1px solid #f0f0f5;
  font-size: 13px;
  color: #555;
}
.detail-item:last-child { border-bottom: none; }
.detail-item .detail-correct { color: #27ae60; font-weight: 600; }
.detail-item .detail-wrong { color: #e74c3c; font-weight: 600; }

/* Error analysis */
.error-analysis {
  text-align: left;
  margin-bottom: 18px;
  padding: 18px;
  background: #fff5f5;
  border-radius: 16px;
  border: 1px solid #ffe0e0;
}
.error-analysis h4 { font-size: 14px; color: #c0392b; margin-bottom: 10px; }

.error-summary {
  font-size: 13px;
  color: #555;
  line-height: 1.8;
  margin-bottom: 12px;
  padding: 10px 14px;
  background: #fff;
  border-radius: 10px;
}

.error-summary-stat {
  display: inline-block;
  margin-right: 16px;
  font-weight: 600;
}
.error-summary-stat .num { font-size: 18px; }
.error-summary-stat .num.red { color: #e74c3c; }
.error-summary-stat .num.green { color: #27ae60; }
.error-summary-stat .label { font-size: 11px; color: #999; display: block; }

.error-tag-group {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}
.error-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 11px;
  font-weight: 600;
  background: #f0f0f5;
  color: #666;
}

.error-list { display: none; }

.error-item {
  padding: 12px 14px;
  background: #fff;
  border-radius: 10px;
  margin-bottom: 8px;
  border-left: 3px solid #e74c3c;
}
.error-item:last-child { margin-bottom: 0; }

.error-item .e-header {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  font-weight: 600;
  color: #c0392b;
  margin-bottom: 4px;
}
.error-item .e-question { font-size: 13px; color: #333; line-height: 1.6; margin-bottom: 4px; }
.error-item .e-answers { font-size: 12px; color: #666; line-height: 1.7; }
.error-item .e-answers .e-wrong-ans { color: #e74c3c; }
.error-item .e-answers .e-correct-ans { color: #27ae60; }
.error-item .e-explain { font-size: 12px; color: #888; margin-top: 4px; font-style: italic; }

.error-toggle {
  display: block;
  width: 100%;
  padding: 8px;
  border: none;
  border-radius: 8px;
  background: #ffe0e0;
  color: #c0392b;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
  text-align: center;
}
.error-toggle:hover { background: #ffd0d0; }

/* Conclusion */
.conclusion-card {
  background: linear-gradient(135deg, #f0f4ff 0%, #fdf0ff 100%);
  border-radius: 16px;
  padding: 22px;
  margin-bottom: 22px;
  text-align: left;
}
.conclusion-card h3 { font-size: 15px; color: #1a1a2e; margin-bottom: 10px; }
.conclusion-text { font-size: 14px; color: #444; line-height: 1.9; }
.conclusion-text strong { color: #1a1a2e; }

.result-actions { display: flex; justify-content: center; }

/* Responsive */
@media (max-width: 768px) {
  body { padding: 20px 14px; }
  .card { padding: 24px 18px; }
  .selector-card { padding: 24px 18px; }
  .index-label { width: 90px; font-size: 12px; }
  .test-card { min-height: 160px; }
}

@media (max-width: 500px) {
  body { padding: 12px 10px; }
  .card { padding: 20px 14px; border-radius: 16px; }
  .selector-card { padding: 20px 14px; }

  /* Language selector */
  .lang-selector select { max-width: 130px; font-size: 12px; padding: 5px 8px; }

  /* Selector */
  .selector-header { margin-bottom: 20px; }
  .selector-logo { font-size: 38px; margin-bottom: 4px; }
  .selector-header h1 { font-size: 20px; line-height: 1.3; }
  .selector-subtitle { font-size: 12px; margin-top: 4px; }
  .test-grid { grid-template-columns: 1fr; gap: 12px; }
  .test-card { min-height: 120px; }
  .test-card-content { padding: 14px; }
  .test-icon { font-size: 28px; margin-bottom: 4px; }
  .test-card-content h3 { font-size: 15px; }
  .test-desc { font-size: 12px; margin-bottom: 6px; }
  .test-meta { font-size: 11px; }

  /* Reminder */
  .reminder-icon { font-size: 36px; margin-bottom: 8px; }
  .reminder-card h2 { font-size: 18px; }
  .reminder-list li { font-size: 13px; padding: 7px 0 7px 22px; }
  .reminder-card .btn { width: 100%; text-align: center; }

  /* Quiz */
  .quiz-card { padding: 16px 14px; }
  .quiz-header { margin-bottom: 14px; }
  .quiz-meta { flex-wrap: wrap; gap: 6px; }
  .badge { font-size: 11px; padding: 3px 10px; }
  .timer { font-size: 14px; padding: 3px 10px; margin-left: auto; }
  .btn-home { font-size: 18px; padding: 4px; }
  .progress-bar { height: 4px; }
  .question-text { font-size: 15px; min-height: 40px; line-height: 1.6; }
  .option {
    padding: 14px 14px;
    font-size: 14px;
    min-height: 48px;
    border-radius: 10px;
    -webkit-tap-highlight-color: rgba(102,126,234,0.15);
  }
  .option:active { background: #eef0ff; }
  .quiz-footer {
    flex-direction: row;
    gap: 10px;
    margin-top: 14px;
  }
  .quiz-footer .btn {
    width: auto;
    padding: 12px 28px;
    font-size: 14px;
  }
  .q-num { display: none; }

  /* Timeout */
  .timeout-icon { font-size: 48px; margin-bottom: 10px; }
  .timeout-card h2 { font-size: 18px; }
  .timeout-text { font-size: 14px; margin-bottom: 18px; }

  /* Result */
  .result-card h2 { font-size: 17px; margin-bottom: 14px; }
  .result-icon-big { font-size: 40px; }
  .result-main { margin-bottom: 16px; }
  .result-main h3 { font-size: 15px; }
  .score-ring { width: 100px; height: 100px; }
  .score-value { font-size: 28px; }
  .score-label { font-size: 15px; }
  .score-desc { font-size: 12px; }

  .index-scores { padding: 14px; }
  .index-scores h3 { font-size: 13px; margin-bottom: 10px; }
  .index-bar { gap: 6px; }
  .index-label { width: 75px; font-size: 11px; }
  .bar-track { height: 14px; }
  .index-score { width: 28px; font-size: 12px; }

  .result-detail h4 { font-size: 13px; }
  .detail-item { font-size: 12px; padding: 4px 0; }

  .error-analysis { padding: 14px; }
  .error-analysis h4 { font-size: 13px; }
  .error-summary { padding: 8px 12px; font-size: 12px; }
  .error-summary-stat .num { font-size: 16px; }
  .error-summary-stat { margin-right: 12px; }
  .error-item { padding: 10px 12px; }
  .error-item .e-header { font-size: 12px; }
  .error-item .e-question { font-size: 12px; }
  .error-item .e-answers { font-size: 11px; }
  .error-toggle { font-size: 12px; padding: 7px; }

  .conclusion-card { padding: 16px; margin-bottom: 16px; }
  .conclusion-card h3 { font-size: 14px; }
  .conclusion-text { font-size: 13px; line-height: 1.8; }

  .result-actions { flex-direction: column; gap: 10px; }
  .result-actions .btn { width: 100%; text-align: center; }

  /* Affiliate */
  .affiliate-section { margin-top: 20px; padding-top: 18px; }
  .affiliate-section h4 { font-size: 12px; margin-bottom: 10px; }
  .affiliate-grid { grid-template-columns: 1fr; gap: 8px; }
  .affiliate-item { padding: 10px; }
  .affiliate-item-icon { width: 36px; height: 36px; font-size: 18px; }
  .affiliate-item-title { font-size: 12px; }
  .affiliate-item-desc { font-size: 10px; }
  .affiliate-tag { font-size: 10px; padding: 2px 6px; }
}

@media (max-width: 380px) {
  body { padding: 8px 8px; }
  .card { padding: 16px 12px; border-radius: 14px; }
  .selector-card { padding: 16px 12px; }
  .quiz-card { padding: 14px 12px; }
  .question-text { font-size: 14px; }
  .option { font-size: 13px; padding: 12px 12px; min-height: 44px; }
  .index-label { width: 60px; font-size: 10px; }
  .badge { font-size: 10px; padding: 2px 8px; }
  .timer { font-size: 12px; padding: 2px 8px; }
  .btn-home { font-size: 16px; padding: 2px; }
  .selector-logo { font-size: 32px; }
  .selector-header h1 { font-size: 18px; }
  .result-card h2 { font-size: 15px; }
  .score-ring { width: 80px; height: 80px; }
  .score-value { font-size: 24px; }
  .lang-selector select { max-width: 110px; font-size: 11px; }
  .conclusion-text { font-size: 12px; }
}

/* Affiliate recommendations */
.affiliate-section {
  margin-top: 28px;
  padding-top: 24px;
  border-top: 1px solid #e8e8f0;
}
.affiliate-section h4 {
  font-size: 13px;
  color: #999;
  font-weight: 500;
  margin-bottom: 14px;
  letter-spacing: 0.5px;
}
.affiliate-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.affiliate-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px;
  background: #f7f8fc;
  border-radius: 12px;
  text-decoration: none;
  transition: all 0.2s;
}
.affiliate-item:hover {
  background: #eef0f8;
  transform: translateY(-1px);
}
.affiliate-item-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}
.affiliate-item-text {
  flex: 1;
  min-width: 0;
}
.affiliate-item-title {
  font-size: 13px;
  font-weight: 600;
  color: #1a1a2e;
  line-height: 1.3;
}
.affiliate-item-desc {
  font-size: 11px;
  color: #999;
  margin-top: 2px;
}
.affiliate-tag {
  font-size: 10px;
  color: #667eea;
  background: rgba(102,126,234,0.1);
  padding: 2px 6px;
  border-radius: 4px;
  font-weight: 500;
}
.feedback-bar {
  text-align: center;
  padding: 20px 10px 30px;
  font-size: 13px;
  color: #8899aa;
  margin-top: auto;
  width: 100%;
  max-width: 780px;
}
.feedback-bar a {
  color: #667eea;
  text-decoration: none;
}
.feedback-bar a:hover {
  text-decoration: underline;
}