/* ===========================
   AWS SAA-C03 Practice Exam
   Dark theme inspired by examtopics
   =========================== */

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

:root {
  --bg-primary: #0f1419;
  --bg-secondary: #1a2129;
  --bg-tertiary: #232b36;
  --bg-card: #1e252e;
  --bg-elevated: #2a3340;
  --bg-hover: #2d3744;
  --border: #2d3744;
  --border-light: #3a4555;
  --text-primary: #e8eaed;
  --text-secondary: #a0aec0;
  --text-muted: #718096;
  --accent: #4299e1;
  --accent-hover: #3182ce;
  --accent-light: rgba(66, 153, 225, 0.15);
  --success: #48bb78;
  --success-light: rgba(72, 187, 120, 0.15);
  --danger: #f56565;
  --danger-light: rgba(245, 101, 101, 0.15);
  --warning: #ed8936;
  --warning-light: rgba(237, 137, 54, 0.15);
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.5);
  --radius: 8px;
  --radius-sm: 6px;
  --radius-lg: 12px;
  --transition: 0.15s ease;
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 15px;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

input {
  font-family: inherit;
}

.hidden {
  display: none !important;
}

/* ===========================
   Loading Screen
   =========================== */
.loading-screen {
  position: fixed;
  inset: 0;
  background: var(--bg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.loading-inner {
  text-align: center;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 16px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ===========================
   App Layout
   =========================== */
.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

/* ===========================
   Top Bar
   =========================== */
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 24px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  height: 64px;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-mark {
  background: var(--accent);
  color: white;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 13px;
  letter-spacing: 0.5px;
}

.logo-text {
  font-weight: 600;
  font-size: 16px;
}

.exam-name {
  color: var(--text-secondary);
  font-size: 13px;
  border-left: 1px solid var(--border-light);
  padding-left: 16px;
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.mode-toggle {
  display: flex;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  padding: 3px;
}

.mode-btn {
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 500;
  border-radius: 5px;
  color: var(--text-secondary);
  transition: var(--transition);
}

.mode-btn:hover {
  color: var(--text-primary);
}

.mode-btn.active {
  background: var(--accent);
  color: white;
}

.timer {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-tertiary);
  padding: 6px 12px;
  border-radius: var(--radius);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  font-size: 14px;
}

.timer.warning {
  color: var(--warning);
  background: var(--warning-light);
}

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

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

.timer-icon {
  width: 14px;
  height: 14px;
  border: 2px solid currentColor;
  border-radius: 50%;
  position: relative;
}

.timer-icon::before {
  content: "";
  position: absolute;
  top: -2px;
  left: 50%;
  width: 2px;
  height: 5px;
  background: currentColor;
  transform: translateX(-50%);
}

.icon-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  transition: var(--transition);
}

.icon-btn:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.icon-btn.active {
  color: var(--warning);
  background: var(--warning-light);
}

/* ===========================
   Layout (Sidebar + Main)
   =========================== */
.layout {
  display: flex;
  flex: 1;
  min-height: 0;
}

/* ===========================
   Sidebar
   =========================== */
.sidebar {
  width: 280px;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 20px 16px;
  flex-shrink: 0;
}

.sidebar-section {
  margin-bottom: 24px;
}

.sidebar-title {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 6px;
  margin-bottom: 12px;
}

.stat {
  background: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  padding: 8px 4px;
  text-align: center;
}

.stat-value {
  font-size: 18px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.stat-label {
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-top: 2px;
  letter-spacing: 0.3px;
}

.stat-answered .stat-value { color: var(--accent); }
.stat-correct .stat-value { color: var(--success); }
.stat-incorrect .stat-value { color: var(--danger); }
.stat-bookmarked .stat-value { color: var(--warning); }
.stat-score .stat-value { color: var(--accent); }

.progress-bar {
  height: 6px;
  background: var(--bg-tertiary);
  border-radius: 3px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--success));
  width: 0%;
  transition: width 0.3s ease;
}

.filter-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.filter-btn {
  text-align: left;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--text-secondary);
  transition: var(--transition);
}

.filter-btn:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.filter-btn.active {
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 500;
}

.search-input {
  width: 100%;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  outline: none;
  transition: var(--transition);
}

.search-input:focus {
  border-color: var(--accent);
  background: var(--bg-elevated);
}

/* ===========================
   Main
   =========================== */
.main {
  flex: 1;
  overflow-y: auto;
  padding: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  min-height: 0;
}

/* ===========================
   Question Card
   =========================== */
.question-card {
  width: 100%;
  max-width: 900px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  flex-shrink: 0;
}

.question-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
}

.question-meta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.question-number {
  font-weight: 700;
  font-size: 16px;
}

.question-topic {
  background: var(--accent);
  color: white;
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 12px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.question-actions {
  display: flex;
  gap: 4px;
}

.question-body {
  padding: 24px;
}

.question-text {
  font-size: 15px;
  line-height: 1.7;
  margin-bottom: 24px;
  white-space: pre-wrap;
  color: var(--text-primary);
}

/* ===========================
   Vote Tally
   =========================== */
.vote-tally {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
  padding: 12px;
  background: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  flex-wrap: wrap;
}

.vote-pill {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 600;
}

.vote-pill.most {
  background: var(--accent-light);
  color: var(--accent);
  border: 1px solid var(--accent);
}

.vote-pill .letter {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  font-size: 10px;
}

.vote-pill.most .letter {
  background: var(--accent);
  color: white;
}

/* ===========================
   Choices
   =========================== */
.choices {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.choice-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
  font-size: 14px;
  line-height: 1.5;
}

.choice-item:hover:not(.disabled) {
  border-color: var(--accent);
  background: var(--bg-tertiary);
}

.choice-item.selected {
  border-color: var(--accent);
  background: var(--accent-light);
}

.choice-item.correct {
  border-color: var(--success);
  background: var(--success-light);
}

.choice-item.incorrect {
  border-color: var(--danger);
  background: var(--danger-light);
}

.choice-item.disabled {
  cursor: default;
}

.choice-letter {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 28px;
  height: 28px;
  padding: 0 8px;
  border-radius: 50%;
  background: var(--bg-tertiary);
  font-weight: 700;
  font-size: 13px;
  color: var(--text-secondary);
  flex-shrink: 0;
}

.choice-item.selected .choice-letter {
  background: var(--accent);
  color: white;
}

.choice-item.correct .choice-letter {
  background: var(--success);
  color: white;
}

.choice-item.incorrect .choice-letter {
  background: var(--danger);
  color: white;
}

.choice-text {
  flex: 1;
  padding-top: 4px;
  white-space: pre-wrap;
}

.choice-marker {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ===========================
   Answer Feedback
   =========================== */
.answer-feedback {
  margin-top: 20px;
  padding: 16px;
  border-radius: var(--radius);
  border-left: 4px solid;
  background: var(--bg-secondary);
}

.answer-feedback.correct {
  border-color: var(--success);
  background: var(--success-light);
}

.answer-feedback.incorrect {
  border-color: var(--danger);
  background: var(--danger-light);
}

.feedback-title {
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.feedback-title.correct { color: var(--success); }
.feedback-title.incorrect { color: var(--danger); }

.feedback-message {
  font-size: 14px;
  color: var(--text-secondary);
}

/* ===========================
   Discussion Section
   =========================== */
.discussion-section {
  margin-top: 20px;
}

.discussion-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--accent);
  text-decoration: none;
  font-size: 13px;
  transition: var(--transition);
}

.discussion-link:hover {
  background: var(--accent-light);
  border-color: var(--accent);
}

/* ===========================
   Question Footer
   =========================== */
.question-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  gap: 12px;
}

.submit-group {
  display: flex;
  gap: 8px;
}

.btn-primary {
  background: var(--accent);
  color: white;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 14px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: var(--transition);
}

.btn-primary:hover:not(:disabled) {
  background: var(--accent-hover);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-weight: 500;
  font-size: 14px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: var(--transition);
  border: 1px solid var(--border-light);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--bg-hover);
}

.btn-block {
  width: 100%;
  justify-content: center;
}

/* ===========================
   Question Nav Grid
   =========================== */
.question-nav {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(48px, 1fr));
  gap: 4px;
  width: 100%;
  max-width: 900px;
  padding: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  flex-shrink: 0;
}

.nav-btn {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-tertiary);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  transition: var(--transition);
}

.nav-btn:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.nav-btn.active {
  border-color: var(--accent);
  background: var(--accent-light);
  color: var(--accent);
}

.nav-btn.answered {
  background: var(--bg-elevated);
  color: var(--accent);
}

.nav-btn.correct {
  background: var(--success-light);
  color: var(--success);
  border-color: var(--success);
}

.nav-btn.incorrect {
  background: var(--danger-light);
  color: var(--danger);
  border-color: var(--danger);
}

.nav-btn.bookmarked::after {
  content: "";
  position: absolute;
  top: 2px;
  right: 2px;
  width: 6px;
  height: 6px;
  background: var(--warning);
  border-radius: 50%;
}

.nav-btn {
  position: relative;
}

/* ===========================
   Topic Info Button
   =========================== */
.topic-info-btn {
  width: 22px;
  height: 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: none;
  cursor: pointer;
  transition: var(--transition);
}

.topic-info-btn:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

/* ===========================
   Topics View
   =========================== */
.topics-view {
  width: 100%;
  max-width: 1100px;
}

.topics-header {
  margin-bottom: 24px;
}

.topics-header h2 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 6px;
}

.topics-subtitle {
  color: var(--text-secondary);
  font-size: 14px;
}

.topics-domain-group {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.topics-domain {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.topics-domain-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.topics-domain-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
}

.topics-domain-count {
  font-size: 13px;
  color: var(--text-muted);
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 12px;
}

.topic-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
}

.topic-card:hover {
  border-color: var(--accent);
  background: var(--bg-elevated);
  transform: translateY(-1px);
}

.topic-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

.topic-card-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
}

.topic-card-count {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.topic-card-description {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.topic-card-progress {
  margin-top: 6px;
}

.topic-progress-bar {
  height: 4px;
  background: var(--bg-tertiary);
  border-radius: 2px;
  overflow: hidden;
}

.topic-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--success));
  width: 0%;
  transition: width 0.3s ease;
}

.topic-progress-info {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 4px;
  font-variant-numeric: tabular-nums;
}

.topic-card-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  width: fit-content;
}

.topic-card-badge.secure { background: rgba(245, 101, 101, 0.15); color: #fc8181; }
.topic-card-badge.resilient { background: rgba(237, 137, 54, 0.15); color: #f6ad55; }
.topic-card-badge.high-performing { background: rgba(66, 153, 225, 0.15); color: #63b3ed; }
.topic-card-badge.cost-optimized { background: rgba(72, 187, 120, 0.15); color: #68d391; }
.topic-card-badge.other { background: rgba(160, 174, 192, 0.15); color: #cbd5e0; }

/* ===========================
   Topic Practice Header Banner
   =========================== */
.topic-practice-banner {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--accent-light);
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  margin-bottom: 16px;
  width: 100%;
  max-width: 900px;
}

.topic-practice-banner-icon {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent);
  color: white;
  border-radius: 50%;
  font-weight: 700;
  font-size: 14px;
}

.topic-practice-banner-text {
  flex: 1;
  font-size: 13px;
  color: var(--text-primary);
}

.topic-practice-banner-text strong {
  color: var(--accent);
}

.topic-practice-banner-exit {
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  background: transparent;
  border: 1px solid var(--border-light);
  color: var(--text-secondary);
  font-size: 12px;
  cursor: pointer;
  transition: var(--transition);
}

.topic-practice-banner-exit:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

/* ===========================
   Modal
   =========================== */
.modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
}

.modal-content {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 480px;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 {
  font-size: 18px;
  font-weight: 600;
}

.modal-body {
  padding: 20px;
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding: 16px 20px;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
}

.setting-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  font-size: 14px;
}

.setting-row label {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.setting-row input[type="number"] {
  width: 100px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  outline: none;
}

.setting-row input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--accent);
}

/* ===========================
   Exam Finished Modal
   =========================== */
.result-summary {
  text-align: center;
  padding: 20px 0;
}

.result-score {
  font-size: 56px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 8px;
}

.result-score.pass { color: var(--success); }
.result-score.fail { color: var(--danger); }

.result-breakdown {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 16px;
  font-size: 14px;
  color: var(--text-secondary);
}

.result-breakdown strong {
  color: var(--text-primary);
  font-size: 16px;
}

.result-verdict {
  font-size: 14px;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: var(--radius);
  display: inline-block;
}

.result-verdict.pass {
  background: var(--success-light);
  color: var(--success);
}

.result-verdict.fail {
  background: var(--danger-light);
  color: var(--danger);
}

/* ===========================
   Scrollbar
   =========================== */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--bg-elevated);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--border-light);
}

/* ===========================
   Responsive
   =========================== */
@media (max-width: 900px) {
  .sidebar {
    display: none;
  }

  .sidebar.open {
    display: block;
    position: fixed;
    top: 64px;
    left: 0;
    bottom: 0;
    z-index: 50;
    width: 280px;
  }

  .main {
    padding: 16px;
  }

  .question-body {
    padding: 16px;
  }

  .question-header,
  .question-footer {
    padding: 12px 16px;
  }

  .topbar {
    padding: 8px 16px;
  }

  .exam-name {
    display: none;
  }

  .mode-btn {
    padding: 4px 8px;
    font-size: 12px;
  }
}