:root {
  --bg-dark: #06080b;
  --bg-panel: #0b0f14;
  --bg-card: #10161d;
  --border-color: rgba(16, 185, 129, 0.1);
  --border-hover: rgba(16, 185, 129, 0.25);
  
  --text-bright: #f3f4f6;
  --text-muted: #8e96a3;
  --text-dark: #4b5563;
  
  --accent-cyan: #06b6d4;
  --accent-green: #10b981;
  --accent-orange: #f59e0b;
  --accent-red: #ef4444;
  
  --font-sans: 'Outfit', sans-serif;
  --font-display: 'Space Grotesk', sans-serif;
  --font-mono: 'Share Tech Mono', monospace;
}

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

body {
  background-color: var(--bg-dark);
  background-image: linear-gradient(rgba(6, 8, 11, 0.82), rgba(6, 8, 11, 0.82)), url('../assets/cyber_study_bg.jpg');
  background-attachment: fixed;
  background-size: cover;
  background-position: center;
  color: var(--text-bright);
  font-family: var(--font-sans);
  min-height: 100vh;
  line-height: 1.5;
  position: relative;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Background glows */
.glow-bg {
  position: absolute;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 1000px;
  height: 600px;
  background: radial-gradient(circle, rgba(16, 185, 129, 0.04) 0%, rgba(6, 182, 212, 0.02) 55%, transparent 70%);
  z-index: -1;
  pointer-events: none;
}

.font-mono {
  font-family: var(--font-mono);
}

/* Header */
.header {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
}

.logo {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.btn-back {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  background: rgba(255, 255, 255, 0.01);
  border: 1px solid var(--border-color);
  padding: 0.4rem 0.9rem;
  border-radius: 0.5rem;
  transition: all 0.2s ease;
}

.btn-back:hover {
  color: var(--text-bright);
  border-color: var(--accent-green);
  background: rgba(16, 185, 129, 0.05);
}

.logo-text {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--accent-green);
  text-shadow: 0 0 10px rgba(16, 185, 129, 0.2);
}

.system-status {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(16, 185, 129, 0.05);
  border: 1px solid rgba(16, 185, 129, 0.15);
  padding: 0.35rem 0.85rem;
  border-radius: 9999px;
}

.status-indicator {
  width: 6px;
  height: 6px;
  background-color: var(--accent-green);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-green);
  animation: blink 1.5s infinite;
}

.status-text {
  font-size: 0.725rem;
  font-weight: 600;
  color: var(--accent-green);
  letter-spacing: 0.05em;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

/* Dashboard Panel / Stats */
.dashboard-panel {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

@media (min-width: 900px) {
  .dashboard-panel {
    grid-template-columns: 1fr 1.5fr;
  }
}

.stats-overview {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.stat-card {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  padding: 1.25rem;
  border-radius: 0.75rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.stat-label {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}

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

/* Domain Mastery Card */
.domain-mastery {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  padding: 1.5rem;
  border-radius: 0.75rem;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.domain-mastery h3 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1.25rem;
  color: var(--text-muted);
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
  padding-bottom: 0.5rem;
}

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

@media (min-width: 600px) {
  .domains-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.domain-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: rgba(255, 255, 255, 0.01);
  border: 1px solid rgba(255, 255, 255, 0.02);
  padding: 0.75rem 1rem;
  border-radius: 0.5rem;
}

.domain-circle-wrapper {
  position: relative;
  width: 70px;
  height: 70px;
}

.domain-circle-wrapper svg {
  transform: rotate(-90deg);
}

.circle-bg {
  fill: none;
  stroke: rgba(255, 255, 255, 0.015);
  stroke-width: 4;
}

.circle-bar {
  fill: none;
  stroke: var(--accent-green);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-dasharray: 176; /* 2 * PI * r (r=28) -> ~175.9 */
  stroke-dashoffset: 176;
  transition: stroke-dashoffset 0.8s ease;
}

/* Match colors to domains */
.domain-card[data-domain="1"] .circle-bar { stroke: var(--accent-green); }
.domain-card[data-domain="2"] .circle-bar { stroke: var(--accent-cyan); }
.domain-card[data-domain="3"] .circle-bar { stroke: var(--accent-orange); }
.domain-card[data-domain="4"] .circle-bar { stroke: var(--accent-red); }

.circle-percent {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-bright);
}

.domain-meta {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.domain-num {
  font-size: 0.65rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.domain-title {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-bright);
  line-height: 1.25;
}

/* Navigation Tabs */
.study-tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1px;
  overflow-x: auto;
}

.tab-btn {
  background: transparent;
  border: 1px solid transparent;
  border-bottom: none;
  color: var(--text-muted);
  padding: 0.75rem 1.5rem;
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border-top-left-radius: 0.5rem;
  border-top-right-radius: 0.5rem;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.tab-btn:hover {
  color: var(--text-bright);
  background: rgba(255, 255, 255, 0.015);
}

.tab-btn.active {
  color: var(--accent-green);
  background: var(--bg-panel);
  border-color: var(--border-color);
  box-shadow: 0 -4px 10px rgba(16, 185, 129, 0.03);
}

/* Tab panes */
.tab-content {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-top: none;
  border-radius: 0 0 1rem 1rem;
  min-height: 400px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  position: relative;
}

.tab-pane {
  display: none;
  padding: 2.25rem;
}

.tab-pane.active {
  display: block;
}

/* Filter Bar */
.filter-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 2rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

.hud-select {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-bright);
  font-family: var(--font-sans);
  padding: 0.4rem 1rem;
  border-radius: 0.5rem;
  outline: none;
  cursor: pointer;
  transition: border-color 0.2s ease;
}

.hud-select:focus {
  border-color: var(--accent-green);
}

/* Flashcards Panel */
.flashcard-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.flashcard-container {
  width: 100%;
  max-width: 500px;
  height: 300px;
  perspective: 1000px;
  margin-bottom: 2rem;
  cursor: pointer;
}

.flashcard {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.flashcard.flipped {
  transform: rotateY(180deg);
}

.card-face {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: 1rem;
  border: 1px solid var(--border-color);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.4);
}

.card-front {
  background: var(--bg-card);
  background-image: radial-gradient(circle at 50% 0%, rgba(16, 185, 129, 0.05) 0%, transparent 60%);
}

.card-back {
  background: #0f1813;
  border-color: rgba(16, 185, 129, 0.25);
  transform: rotateY(180deg);
}

.card-domain-tag {
  font-family: var(--font-mono);
  font-size: 0.725rem;
  font-weight: 700;
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.2);
  background: rgba(16, 185, 129, 0.05);
  padding: 0.2rem 0.65rem;
  border-radius: 0.25rem;
  margin-bottom: 1.5rem;
  text-transform: uppercase;
}

.card-term {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 2rem;
  line-height: 1.3;
}

.definition-header {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

.card-definition {
  font-size: 1.05rem;
  line-height: 1.5;
  color: var(--text-bright);
}

.click-hint {
  font-size: 0.675rem;
  color: var(--text-dark);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: auto;
}

/* Controls block */
.hud-controls {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.btn-hud {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-bright);
  padding: 0.5rem 1.25rem;
  border-radius: 0.5rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-hud:hover:not(:disabled) {
  border-color: var(--accent-green);
  background: rgba(16, 185, 129, 0.05);
}

.btn-hud:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.btn-warn {
  border-color: rgba(245, 158, 11, 0.3);
  color: var(--accent-orange);
}

.btn-warn:hover {
  border-color: var(--accent-orange) !important;
  background: rgba(245, 158, 11, 0.05) !important;
}

.hud-counter {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

/* Practice Quiz Panel */
.quiz-panel {
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.hud-badge {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.06);
  border: 1px solid rgba(6, 182, 212, 0.2);
  padding: 0.25rem 0.75rem;
  border-radius: 0.25rem;
}

.btn-bookmark {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-dark);
  font-size: 1.15rem;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.btn-bookmark:hover {
  color: var(--accent-orange);
  border-color: var(--accent-orange);
  background: rgba(245, 158, 11, 0.05);
}

.btn-bookmark.active {
  color: var(--accent-orange);
  border-color: var(--accent-orange);
  background: rgba(245, 158, 11, 0.12);
  text-shadow: 0 0 8px var(--accent-orange);
}

.quiz-question {
  font-size: 1.15rem;
  font-weight: 500;
  line-height: 1.5;
  margin-bottom: 2rem;
  color: var(--text-bright);
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.option-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-bright);
  padding: 1rem 1.25rem;
  border-radius: 0.75rem;
  text-align: left;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  cursor: pointer;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  transition: all 0.25s ease;
}

.option-btn:hover:not(.disabled) {
  border-color: var(--accent-green);
  background: rgba(16, 185, 129, 0.03);
}

.option-letter {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.2);
  padding: 0.05rem 0.35rem;
  border-radius: 0.25rem;
  font-size: 0.8rem;
}

/* Option feedback status */
.option-btn.correct {
  border-color: var(--accent-green);
  background: rgba(16, 185, 129, 0.08);
  box-shadow: 0 0 15px rgba(16, 185, 129, 0.1);
}

.option-btn.correct .option-letter {
  background: var(--accent-green);
  color: #07090c;
  border-color: var(--accent-green);
}

.option-btn.incorrect {
  border-color: var(--accent-red);
  background: rgba(239, 68, 68, 0.08);
}

.option-btn.incorrect .option-letter {
  background: var(--accent-red);
  color: #07090c;
  border-color: var(--accent-red);
}

.option-btn.disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Explanation Container */
.quiz-explanation-box {
  background: #0f161c;
  border: 1px solid rgba(6, 182, 212, 0.15);
  border-radius: 0.75rem;
  padding: 1.5rem;
  margin-bottom: 2rem;
  display: none; /* revealed on answer selection */
}

.quiz-explanation-box h4 {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.quiz-explanation-box.correct h4 { color: var(--accent-green); }
.quiz-explanation-box.incorrect h4 { color: var(--accent-red); }

.quiz-explanation-box p {
  font-size: 0.925rem;
  line-height: 1.55;
  color: var(--text-muted);
}

.quiz-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Mock Exam Setup Screen */
.mock-panel {
  width: 100%;
  max-width: 650px;
  margin: 0 auto;
  text-align: center;
}

.mock-setup-screen h2,
.mock-results-screen h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.mock-setup-screen p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 2rem;
}

.mock-specs {
  display: flex;
  justify-content: space-around;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 1.5rem 1rem;
  border-radius: 0.75rem;
  margin-bottom: 2.5rem;
}

.spec-item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.spec-label {
  font-size: 0.675rem;
  font-weight: 700;
  color: var(--text-dark);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.spec-value {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--accent-cyan);
}

.btn-primary-hud {
  background: var(--accent-green);
  border: none;
  color: #07090b;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  padding: 0.85rem 2rem;
  border-radius: 0.5rem;
  cursor: pointer;
  letter-spacing: 0.02em;
  box-shadow: 0 4px 20px rgba(16, 185, 129, 0.25);
  transition: all 0.2s ease;
}

.btn-primary-hud:hover {
  filter: brightness(1.1);
  box-shadow: 0 4px 25px rgba(16, 185, 129, 0.4);
}

/* Active Mock Exam Screen */
.mock-active-screen {
  display: none;
  text-align: left;
}

.mock-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
  padding-bottom: 0.75rem;
  margin-bottom: 1.5rem;
}

.mock-timer {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--accent-cyan);
  text-shadow: 0 0 10px rgba(6, 182, 212, 0.2);
  background: rgba(6, 182, 212, 0.05);
  border: 1px solid rgba(6, 182, 212, 0.15);
  padding: 0.25rem 0.85rem;
  border-radius: 0.25rem;
}

/* Results panel */
.mock-results-screen {
  display: none;
}

.results-layout {
  display: flex;
  flex-direction: column;
  gap: 2rem;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 2.25rem;
  border-radius: 0.75rem;
  margin-bottom: 2.5rem;
}

@media (min-width: 600px) {
  .results-layout {
    flex-direction: row;
    justify-content: space-around;
  }
}

.results-score {
  display: flex;
  flex-direction: column;
  align-items: center;
}

#results-pct {
  font-size: 3.5rem;
  font-weight: 700;
  color: var(--accent-green);
  text-shadow: 0 0 15px rgba(16, 185, 129, 0.2);
}

.results-label {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.65rem;
  border-radius: 0.25rem;
}

.results-label.pass {
  background: rgba(16, 185, 129, 0.08);
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.2);
}

.results-label.fail {
  background: rgba(239, 68, 68, 0.08);
  color: var(--accent-red);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.results-data {
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.results-data p {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.results-data span {
  color: var(--text-bright);
  font-weight: 600;
}

/* Deck Curator Form Styles */
.curator-panel {
  max-width: 900px;
  margin: 0 auto;
}

.curator-panel h2 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

.curator-panel p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 2.25rem;
}

.curator-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
}

@media (min-width: 900px) {
  .curator-layout {
    grid-template-columns: 0.9fr 1.1fr;
  }
}

.curator-form {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 1.75rem;
  border-radius: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.curator-form h3 {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--accent-green);
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
  padding-bottom: 0.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.form-row {
  display: flex;
  gap: 1rem;
}

.form-row .form-group {
  flex: 1;
}

.curator-form label {
  font-size: 0.725rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.curator-form input,
.curator-form select,
.curator-form textarea {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  color: var(--text-bright);
  font-family: var(--font-sans);
  padding: 0.6rem 0.85rem;
  border-radius: 0.5rem;
  outline: none;
  font-size: 0.9rem;
}

.curator-form input:focus,
.curator-form select:focus,
.curator-form textarea:focus {
  border-color: var(--accent-green);
}

.curator-form textarea {
  resize: vertical;
  min-height: 80px;
}

.btn-curate {
  background: transparent;
  border: 1px solid var(--accent-green);
  color: var(--accent-green);
  font-family: var(--font-display);
  font-weight: 700;
  padding: 0.65rem 1rem;
  border-radius: 0.5rem;
  cursor: pointer;
  transition: all 0.2s ease;
  margin-top: 0.5rem;
}

.btn-curate:hover {
  background: rgba(16, 185, 129, 0.08);
  box-shadow: 0 0 10px rgba(16, 185, 129, 0.15);
}

.form-status {
  font-size: 0.775rem;
  font-weight: 600;
  text-align: center;
}

.form-status.success { color: var(--accent-green); }
.form-status.error { color: var(--accent-red); }

/* Footer */
.main-footer {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  text-align: center;
  border-top: 1px solid var(--border-color);
  font-size: 0.8rem;
  color: var(--text-dark);
  margin-top: 4rem;
}

/* Animations */
@keyframes blink {
  50% { opacity: 0.4; }
}

/* ==========================================
   CONCEPT GUIDES TAB STYLE RULES
   ========================================== */
.guides-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.25rem;
}

@media (min-width: 800px) {
  .guides-layout {
    grid-template-columns: 240px 1fr;
  }
}

/* Sidebar selector list */
.guides-sidebar {
  border-right: none;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1.5rem;
}

@media (min-width: 800px) {
  .guides-sidebar {
    border-right: 1px solid var(--border-color);
    border-bottom: none;
    padding-right: 1.75rem;
    padding-bottom: 0;
  }
}

.guides-sidebar h3 {
  font-family: var(--font-display);
  font-size: 0.8rem;
  text-transform: uppercase;
  color: var(--text-dark);
  letter-spacing: 0.05em;
  margin-bottom: 1.25rem;
}

.guides-menu {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

@media (min-width: 800px) {
  .guides-menu {
    flex-direction: column;
    flex-wrap: nowrap;
  }
}

.guide-menu-item {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 0.6rem 0.85rem;
  border-radius: 0.5rem;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}

@media (min-width: 800px) {
  .guide-menu-item {
    white-space: normal;
  }
}

.guide-menu-item:hover {
  color: var(--text-bright);
  border-color: var(--accent-green);
  background: rgba(16, 185, 129, 0.02);
}

.guide-menu-item.active {
  color: var(--accent-green);
  border-color: var(--accent-green);
  background: rgba(16, 185, 129, 0.08);
  font-weight: 600;
}

/* Viewer detail display */
.guides-viewer {
  min-height: 400px;
}

.guide-detail {
  display: none;
  animation: fadeIn 0.4s ease forwards;
}

.guide-detail.active {
  display: block;
}

.guide-detail h2 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-bright);
}

.guide-intro {
  font-size: 0.95rem;
  line-height: 1.55;
  color: var(--text-muted);
}

.guide-grid-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.25rem;
  margin-top: 1.5rem;
  align-items: flex-start;
}

@media (min-width: 950px) {
  .guide-grid-container {
    grid-template-columns: 1.1fr 0.9fr; /* Left text block, Right graphic block */
  }
}

.guide-text-col {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.guide-graphic-col {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.guide-graphic {
  background: #090e13;
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  padding: 1.5rem;
  display: flex;
  justify-content: center;
  align-items: center;
}

.guide-svg {
  width: 100%;
  max-width: 680px;
  height: auto;
}

/* SVG Timeline details */
.timeline-path {
  stroke: rgba(255, 255, 255, 0.25);
  stroke-width: 3;
  fill: none;
}

.timeline-path.rpo-line {
  stroke: var(--accent-red);
  stroke-dasharray: 4 4;
}

/* Master rule to make structural graphic borders highly visible in dark mode */
.guide-svg line,
.guide-svg polygon {
  stroke: rgba(16, 185, 129, 0.45) !important;
}

.svg-label {
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 700;
  text-anchor: middle;
  text-transform: uppercase;
}

.red-text { fill: var(--accent-red); }
.cyan-text { fill: var(--accent-cyan); }
.orange-text { fill: var(--accent-orange); }
.green-text { fill: var(--accent-green); }

.svg-point-label {
  font-size: 11px;
  fill: #9ca3af;
  text-anchor: middle;
}

.svg-point-label.bold {
  font-weight: 700;
  fill: #f3f4f6;
}

/* Pulse point highlight */
.pulse-point {
  animation: pulsePoint 2s infinite ease-in-out;
}

@keyframes pulsePoint {
  0% { r: 7; opacity: 1; }
  50% { r: 10; opacity: 0.7; }
  100% { r: 7; opacity: 1; }
}

/* Guide notes section */
.guide-notes {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  padding: 1.5rem;
}

.guide-notes h4 {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--accent-green);
  margin-bottom: 0.75rem;
  letter-spacing: 0.05em;
}

.guide-notes ul {
  padding-left: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.guide-notes li {
  font-size: 0.9rem;
  line-height: 1.5;
  color: var(--text-muted);
}

.guide-notes li strong {
  color: var(--text-bright);
}

.guide-notes code {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  color: var(--accent-cyan);
  padding: 0.15rem 0.4rem;
  border-radius: 0.25rem;
  font-size: 0.825rem;
}

/* Chevron groups */
.chevron-group polygon {
  stroke: rgba(255, 255, 255, 0.25) !important;
  transition: all 0.3s ease;
}

.chevron-text {
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  fill: #f3f4f6;
  text-anchor: middle;
}

.chevron-sub {
  font-family: var(--font-mono);
  font-size: 9px;
  fill: #9ca3af;
  text-anchor: middle;
}

.chevron-group.active polygon {
  fill: rgba(6, 182, 212, 0.04);
  stroke: var(--accent-cyan) !important;
}

.chevron-group.active .chevron-text {
  fill: #f3f4f6;
}

.chevron-group.active .chevron-sub {
  fill: var(--accent-cyan);
}

.chevron-group.highlight polygon {
  stroke: var(--accent-green) !important;
  animation: containPulse 2s infinite ease-in-out;
}

.chevron-group.highlight .chevron-text,
.chevron-group.highlight .chevron-sub {
  fill: #07090b;
}

@keyframes containPulse {
  0% { fill: rgba(16, 185, 129, 0.9); }
  50% { fill: rgba(16, 185, 129, 0.75); }
  100% { fill: rgba(16, 185, 129, 0.9); }
}

/* Control Matrix Table */
.control-matrix {
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  overflow: hidden;
  margin-bottom: 1.75rem;
}

.control-matrix table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  background: var(--bg-card);
  color: var(--text-bright);
}

.control-matrix th,
.control-matrix td {
  padding: 1rem 1.25rem;
  font-size: 0.875rem;
  line-height: 1.5;
  border-bottom: 1px solid var(--border-color);
}

.control-matrix th {
  background: rgba(6, 182, 212, 0.05);
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--accent-cyan);
}

.control-matrix td {
  color: var(--text-muted);
}

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

/* Pyramid SVG styles */
.pyramid-text {
  font-family: var(--font-display);
  font-size: 12px;
  fill: var(--text-bright);
  text-anchor: middle;
}

.pyramid-sub {
  font-size: 9px;
  fill: var(--accent-cyan);
  text-anchor: middle;
}

/* Math blocks layout */
.math-flow-container {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-bottom: 1.75rem;
}

.math-block {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 1.25rem 1.5rem;
  border-radius: 0.75rem;
}

.math-title {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--accent-orange);
  margin-bottom: 0.5rem;
  letter-spacing: 0.05em;
}

.math-formula {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 0.4rem;
}

.math-desc {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  color: var(--text-muted);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(5px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Operator Select Profile Layout */
.operator-card {
  grid-column: span 2;
  border-color: rgba(6, 182, 212, 0.25) !important;
  background: rgba(6, 182, 212, 0.03) !important;
}

.operator-select {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--accent-cyan);
  padding: 0.5rem 0.75rem;
  border-radius: 0.5rem;
  font-size: 0.95rem;
  font-weight: 700;
  outline: none;
  cursor: pointer;
  margin-top: 0.4rem;
  transition: all 0.2s ease;
  box-shadow: 0 0 8px rgba(6, 182, 212, 0.1);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.operator-select:hover {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 10px rgba(6, 182, 212, 0.2);
}

.operator-select option {
  background: var(--bg-dark);
  color: var(--text-bright);
}