/* VSPD in Hadronic Physics — Professional palette & glass-morphism */

:root {
  --heavy-ion-gold: #d4a84b;
  --heavy-ion-gold-dim: rgba(212, 168, 75, 0.75);
  --plasma-blue: #508cdc;
  --plasma-blue-dim: rgba(80, 140, 220, 0.5);
  --vector-star-red: #c83c3c;
  --vector-star-red-dim: rgba(200, 60, 60, 0.85);
  --bg-dark: #0c0e16;
  --bg-card: rgba(18, 22, 32, 0.85);
  --glass-bg: rgba(255, 255, 255, 0.06);
  --glass-border: rgba(255, 255, 255, 0.1);
  --text-primary: rgba(240, 240, 245, 0.98);
  --text-secondary: rgba(200, 200, 210, 0.85);
  --measurement-window: rgba(255, 220, 100, 0.3);
  --font-sans: 'Inter', 'Roboto', system-ui, -apple-system, sans-serif;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  background: var(--bg-dark);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.5;
}

/* Glass-morphism navigation bar */
.nav-bar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.5rem;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
}

.nav-bar .title {
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text-primary);
}

.nav-tabs {
  display: flex;
  gap: 0.25rem;
}

.nav-tabs button {
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 8px;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.nav-tabs button:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
}

.nav-tabs button.active {
  background: var(--plasma-blue-dim);
  color: var(--text-primary);
}

/* Main content */
.main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem;
}

.module {
  display: none;
  animation: fadeIn 0.25s ease;
}

.module.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* Theory / Application sections */
.section-card {
  background: var(--bg-card);
  border-radius: 12px;
  border: 1px solid var(--glass-border);
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}

.section-card h2 {
  margin: 0 0 1rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--heavy-ion-gold);
}

/* Synthesis slider */
.synthesis-control {
  margin: 1rem 0;
}

.synthesis-control label {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.synthesis-control input[type="range"] {
  width: 100%;
  max-width: 400px;
  height: 8px;
  border-radius: 4px;
  background: var(--glass-bg);
  accent-color: var(--heavy-ion-gold);
}

/* Model toggle */
.model-toggle {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin: 1rem 0;
}

.model-toggle label {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.model-toggle select {
  padding: 0.4rem 0.75rem;
  border-radius: 6px;
  border: 1px solid var(--glass-border);
  background: var(--bg-card);
  color: var(--text-primary);
  font-family: var(--font-sans);
}

/* Canvas containers */
.canvas-container {
  position: relative;
  width: 100%;
  min-height: 320px;
  border-radius: 8px;
  overflow: hidden;
  background: rgba(10, 12, 20, 0.9);
}

.canvas-container.theory {
  min-height: 380px;
}

.canvas-container.temporal {
  min-height: 140px;
}

/* Measurement window hint */
.measurement-hint {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
}

/* Explanation section: plain-language overview */
.explanation-card {
  max-width: 720px;
}

.explanation-lead {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  line-height: 1.6;
}

.explanation-card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--plasma-blue);
  margin: 1.25rem 0 0.5rem;
}

.explanation-list {
  margin: 0 0 0.5rem;
  padding-left: 1.25rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.65;
}

.explanation-list li {
  margin-bottom: 0.6rem;
}

.explanation-terms {
  margin: 0.5rem 0 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.explanation-terms dt {
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 0.75rem;
}

.explanation-terms dd {
  margin: 0.2rem 0 0 1rem;
  line-height: 1.5;
}

.explanation-inline {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.control-hint {
  display: block;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}