/* style.css - Nouă fotoni în întuneric / Nine Photons in the Dark */
:root {
  --bg-space: #06080d;
  --bg-card: #0c101a;
  --bg-card-subtle: #121824;
  --border-color: #1e283a;
  --border-focus: #34d399;
  --text-primary: #e6edf3;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-rhodopsin: #10b981;
  --accent-rhodopsin-glow: rgba(16, 185, 129, 0.25);
  --accent-rhodopsin-bright: #34d399;
  --accent-scotopic: #fbbf24;
  --accent-scotopic-glow: rgba(251, 191, 36, 0.2);
  --accent-dark-current: #38bdf8;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", Menlo, Monaco, Consolas, monospace;
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-space);
  color: var(--text-primary);
  line-height: 1.65;
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-x: hidden;
  position: relative;
}

/* Background scotopic noise texture */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at 50% 20%, rgba(16, 185, 129, 0.04) 0%, transparent 70%),
              radial-gradient(circle at 80% 80%, rgba(251, 191, 36, 0.02) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.container {
  width: 100%;
  max-width: 900px;
  padding: 0 1.25rem;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

/* Header & Nav */
header.site-header {
  width: 100%;
  border-bottom: 1px solid var(--border-color);
  background-color: rgba(6, 8, 13, 0.85);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0.875rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  text-decoration: none;
  color: var(--text-primary);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.site-brand svg {
  color: var(--accent-rhodopsin);
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 9999px;
  padding: 0.2rem 0.25rem;
  gap: 0.25rem;
}

.lang-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.25rem 0.625rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  border-radius: 9999px;
  transition: all 0.15s ease;
}

.lang-link:hover {
  color: var(--text-primary);
}

.lang-link.active {
  background: var(--accent-rhodopsin);
  color: #04120a;
}

/* Hero Section */
.hero {
  padding: 4.5rem 0 3rem;
  text-align: left;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  font-family: var(--font-mono);
  color: var(--accent-rhodopsin-bright);
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.25);
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  margin-bottom: 1.5rem;
}

.hero-tag-pulse {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-rhodopsin);
  box-shadow: 0 0 8px var(--accent-rhodopsin);
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.8); }
}

h1.hero-title {
  font-size: clamp(2.125rem, 5vw, 3.25rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: #ffffff;
  margin-bottom: 1.25rem;
}

.hero-subtitle {
  font-size: clamp(1.0625rem, 2.5vw, 1.25rem);
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 780px;
}

/* Highlight metrics grid */
.metric-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin: 2.5rem 0 3.5rem;
}

.metric-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.25rem;
  position: relative;
  overflow: hidden;
}

.metric-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-rhodopsin), transparent);
}

.metric-card.scotopic::before {
  background: linear-gradient(90deg, var(--accent-scotopic), transparent);
}

.metric-card.dark-current::before {
  background: linear-gradient(90deg, var(--accent-dark-current), transparent);
}

.metric-value {
  font-size: 2rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: #ffffff;
  line-height: 1.1;
  margin-bottom: 0.375rem;
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
}

.metric-unit {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
}

.metric-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.metric-desc {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.45;
}

/* Sections */
section {
  padding: 2.5rem 0;
  border-top: 1px solid var(--border-color);
}

h2.section-title {
  font-size: 1.625rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #ffffff;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.625rem;
}

.section-lead {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  margin-bottom: 1.75rem;
  max-width: 780px;
}

p {
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}

/* Interactive Card / Tool Box */
.tool-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.5rem;
  margin: 1.75rem 0 2.5rem;
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.4);
}

.tool-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.tool-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: #ffffff;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.tool-badge {
  font-size: 0.6875rem;
  font-family: var(--font-mono);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
}

/* Canvas styling */
.canvas-wrapper {
  width: 100%;
  background: #030407;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  overflow: hidden;
  position: relative;
  margin-bottom: 1.25rem;
}

canvas {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
}

/* Controls */
.controls-panel {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.control-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8125rem;
  color: var(--text-secondary);
}

.control-val-readout {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--accent-rhodopsin-bright);
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: var(--border-color);
  border-radius: 3px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-rhodopsin-bright);
  cursor: pointer;
  box-shadow: 0 0 8px var(--accent-rhodopsin-glow);
  transition: transform 0.1s ease;
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

.btn-group {
  display: flex;
  gap: 0.625rem;
  flex-wrap: wrap;
}

.action-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: var(--accent-rhodopsin);
  color: #031409;
  font-weight: 700;
  font-size: 0.875rem;
  padding: 0.625rem 1.25rem;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: all 0.15s ease;
}

.action-btn:hover {
  background: #34d399;
  box-shadow: 0 0 16px var(--accent-rhodopsin-glow);
}

.action-btn.secondary {
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
}

.action-btn.secondary:hover {
  background: #1e283a;
}

/* Oscilloscope & Status Bars */
.status-display-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.75rem;
  margin-top: 1rem;
}

.status-box {
  background: #04060a;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 0.75rem;
}

.status-box-title {
  font-size: 0.6875rem;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}

.status-box-val {
  font-family: var(--font-mono);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--accent-rhodopsin-bright);
}

/* Kohlrausch & Contrast Acuity Test */
.kohlrausch-test-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: #020305;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 2rem 1rem;
  margin: 1.25rem 0;
  position: relative;
}

.target-circle {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  transition: background-color 0.2s ease, opacity 0.2s ease;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: bold;
}

.test-instructions {
  font-size: 0.8125rem;
  color: var(--text-muted);
  text-align: center;
  max-width: 480px;
}

/* Scientific Equations & Breakdown */
.equation-card {
  background: #080c14;
  border: 1px solid var(--border-color);
  border-left: 3px solid var(--accent-rhodopsin);
  border-radius: 8px;
  padding: 1.25rem;
  margin: 1.5rem 0;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--text-primary);
  overflow-x: auto;
}

.equation-card em {
  font-style: normal;
  color: var(--accent-rhodopsin-bright);
  font-weight: 600;
}

/* Methodological table */
.data-table-wrapper {
  width: 100%;
  overflow-x: auto;
  margin: 1.75rem 0;
  border: 1px solid var(--border-color);
  border-radius: 10px;
}

table.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  text-align: left;
}

table.data-table th,
table.data-table td {
  padding: 0.875rem 1rem;
  border-bottom: 1px solid var(--border-color);
}

table.data-table th {
  background: var(--bg-card-subtle);
  color: var(--text-secondary);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

table.data-table tr:last-child td {
  border-bottom: none;
}

table.data-table td.numeric {
  font-family: var(--font-mono);
  color: var(--accent-rhodopsin-bright);
}

/* Literature & Reference Notes */
.sources-list {
  list-style: none;
  margin: 1.5rem 0;
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.sources-list li {
  font-size: 0.875rem;
  color: var(--text-secondary);
  padding-left: 1.25rem;
  position: relative;
}

.sources-list li::before {
  content: "•";
  color: var(--accent-rhodopsin);
  position: absolute;
  left: 0;
  top: 0;
  font-weight: bold;
}

/* Footer */
footer.site-footer {
  width: 100%;
  border-top: 1px solid var(--border-color);
  background-color: #04060a;
  padding: 3rem 0;
  margin-top: auto;
  color: var(--text-muted);
  font-size: 0.8125rem;
}

.footer-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-back-to-top {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.8125rem;
  padding: 0.375rem 0.75rem;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  transition: all 0.15s ease;
}

.footer-back-to-top:hover {
  color: var(--text-primary);
  border-color: var(--accent-rhodopsin);
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* Mobile adjustments */
@media (max-width: 640px) {
  .hero {
    padding: 3rem 0 2rem;
  }
  .tool-box {
    padding: 1rem;
  }
  .controls-panel {
    grid-template-columns: 1fr;
    padding: 1rem;
  }
  .metric-value {
    font-size: 1.625rem;
  }
}