/* NIGHTWAVE WebSDR - Modern Futuristic CSS */

/* ========== CSS Variables ========== */
:root {
  /* Colors */
  --color-primary-bg: #0D1117;
  --color-secondary-bg: #1C1F26;
  --color-accent-cyan: #00E5FF;
  --color-accent-green: #7FFF00;
  --color-text-primary: #FFFFFF;
  --color-text-secondary: #B0B8C4;
  --color-error: #FF3355;
  --color-border: #30363d;
  --color-hover: #21262d;
  
  /* Typography */
  --font-heading: 'Exo 2', sans-serif;
  --font-body: 'Roboto', sans-serif;
  --font-mono: 'Roboto Mono', monospace;
  
  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-xxl: 48px;
  
  /* Layout */
  --container-max-width: 1400px;
  --border-radius: 8px;
  --border-radius-sm: 4px;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* Shadows */
  --shadow-glow-cyan: 0 0 15px rgba(0, 229, 255, 0.3);
  --shadow-glow-green: 0 0 15px rgba(127, 255, 0, 0.3);
  --shadow-card: 0 4px 12px rgba(0, 0, 0, 0.3);
}

/* ========== Base Styles ========== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background: var(--color-primary-bg);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

/* ========== Background Pattern ========== */
.background-pattern {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(rgba(0, 229, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 229, 255, 0.03) 1px, transparent 1px);
  background-size: 20px 20px;
  pointer-events: none;
  z-index: -1;
}

.background-pattern::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 25% 25%, rgba(0, 229, 255, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 75% 75%, rgba(127, 255, 0, 0.05) 0%, transparent 50%);
  animation: backgroundShift 20s linear infinite;
}

@keyframes backgroundShift {
  0% { transform: translate(0, 0); }
  25% { transform: translate(-10px, -10px); }
  50% { transform: translate(-20px, 0); }
  75% { transform: translate(-10px, 10px); }
  100% { transform: translate(0, 0); }
}

/* ========== Typography ========== */
h1, h2, h3 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
}

h1 {
  font-size: 3rem;
  letter-spacing: 1.5px;
  text-transform: uppercase;
}

h2 {
  font-size: 1.75rem;
  letter-spacing: 1px;
  margin-bottom: var(--spacing-md);
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-sm);
}

/* ========== Container & Layout ========== */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.grid-layout {
  display: grid;
  grid-template-columns: 350px 1fr;
  gap: var(--spacing-lg);
  min-height: calc(100vh - 120px);
}

/* ========== Header ========== */
.header {
  background: rgba(28, 31, 38, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-md) 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header-title {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.title-main {
  color: var(--color-accent-cyan);
  font-size: 2.5rem;
  text-shadow: var(--shadow-glow-cyan);
}

.title-sub {
  color: var(--color-text-secondary);
  font-size: 1rem;
  font-weight: 400;
  letter-spacing: 2px;
  margin-top: -8px;
}

.header-info {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.header-stats {
  color: var(--color-text-secondary);
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

.header-button {
  background: transparent;
  border: 1px solid var(--color-accent-cyan);
  color: var(--color-accent-cyan);
  padding: var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.header-button:hover {
  background: var(--color-accent-cyan);
  color: var(--color-primary-bg);
  box-shadow: var(--shadow-glow-cyan);
}

/* ========== Panels ========== */
.station-list-panel,
.control-panel {
  background: var(--color-secondary-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  height: fit-content;
  box-shadow: var(--shadow-card);
}

.panel-header {
  margin-bottom: var(--spacing-lg);
}

.panel-header h2 {
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-md);
}

/* ========== Station List ========== */
.search-container {
  position: relative;
  margin-bottom: var(--spacing-md);
}

.search-input {
  width: 100%;
  background: var(--color-primary-bg);
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
  padding: var(--spacing-sm) var(--spacing-md);
  padding-right: 40px;
  border-radius: var(--border-radius-sm);
  font-size: 0.9rem;
  transition: all var(--transition-fast);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-accent-cyan);
  box-shadow: 0 0 10px rgba(0, 229, 255, 0.2);
}

.search-icon {
  position: absolute;
  right: var(--spacing-sm);
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-secondary);
  pointer-events: none;
}

.filter-container {
  margin-bottom: var(--spacing-md);
}

.filter-select {
  width: 100%;
  background: var(--color-primary-bg);
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius-sm);
  font-size: 0.9rem;
  cursor: pointer;
}

.filter-select:focus {
  outline: none;
  border-color: var(--color-accent-cyan);
}

.station-list {
  max-height: 60vh;
  overflow-y: auto;
  padding-right: var(--spacing-xs);
}

.station-list::-webkit-scrollbar {
  width: 6px;
}

.station-list::-webkit-scrollbar-track {
  background: var(--color-primary-bg);
  border-radius: 3px;
}

.station-list::-webkit-scrollbar-thumb {
  background: var(--color-accent-cyan);
  border-radius: 3px;
}

.station-item {
  background: var(--color-primary-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-sm);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}

.station-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: transparent;
  transition: all var(--transition-fast);
}

.station-item:hover {
  background: var(--color-hover);
  transform: translateX(2px);
}

.station-item:hover::before {
  background: var(--color-accent-cyan);
}

.station-item.active {
  background: var(--color-hover);
  border-color: var(--color-accent-cyan);
  box-shadow: var(--shadow-glow-cyan);
}

.station-item.active::before {
  background: var(--color-accent-cyan);
}

.station-name {
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
  font-size: 1rem;
}

.station-location {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  margin-bottom: var(--spacing-xs);
}

.station-bands {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
}

.band-tag {
  background: rgba(0, 229, 255, 0.2);
  color: var(--color-accent-cyan);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.75rem;
  font-family: var(--font-mono);
}

.station-status {
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent-green);
  box-shadow: 0 0 6px var(--color-accent-green);
}

.station-status.inactive {
  background: var(--color-error);
  box-shadow: 0 0 6px var(--color-error);
}

/* ========== Control Panel ========== */
.control-panel {
  position: sticky;
  top: 100px;
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.9rem;
}

.status-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-accent-green);
  box-shadow: 0 0 8px var(--color-accent-green);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.status-text {
  color: var(--color-text-secondary);
  font-family: var(--font-mono);
}

/* ========== Station Info Display ========== */
.station-info-display {
  background: var(--color-primary-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  min-height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.no-station-selected {
  text-align: center;
  color: var(--color-text-secondary);
}

.no-station-selected svg {
  margin-bottom: var(--spacing-sm);
}

.station-details {
  width: 100%;
}

.station-details-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--spacing-md);
}

.station-details-name {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-accent-cyan);
  margin-bottom: var(--spacing-xs);
}

.station-details-location {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

.station-details-qth {
  font-family: var(--font-mono);
  color: var(--color-accent-green);
  font-size: 0.9rem;
  padding: var(--spacing-xs) var(--spacing-sm);
  background: rgba(127, 255, 0, 0.1);
  border-radius: var(--border-radius-sm);
  border: 1px solid rgba(127, 255, 0, 0.3);
}

.station-details-info {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.info-item {
  background: rgba(0, 229, 255, 0.05);
  padding: var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  border: 1px solid rgba(0, 229, 255, 0.2);
}

.info-label {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xs);
}

.info-value {
  font-size: 0.9rem;
  color: var(--color-text-primary);
  font-family: var(--font-mono);
}

.station-bands-list {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
}

/* ========== Spectrum Visualizer ========== */
.spectrum-container {
  background: var(--color-primary-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.spectrum-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
}

.spectrum-button {
  background: transparent;
  border: 1px solid var(--color-accent-green);
  color: var(--color-accent-green);
  padding: var(--spacing-xs);
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.spectrum-button:hover {
  background: var(--color-accent-green);
  color: var(--color-primary-bg);
}

.spectrum-display {
  background: #000;
  border-radius: var(--border-radius-sm);
  padding: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

#spectrumCanvas {
  width: 100%;
  height: 120px;
  display: block;
}

.spectrum-info {
  margin-top: var(--spacing-sm);
}

.frequency-markers {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
}

.center-freq {
  color: var(--color-accent-cyan);
  font-weight: 600;
}

/* ========== Frequency Control ========== */
.frequency-control {
  background: var(--color-primary-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.frequency-display {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  background: #000;
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  border: 2px solid var(--color-accent-green);
  box-shadow: inset 0 0 20px rgba(127, 255, 0, 0.1);
}

.frequency-label {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  font-family: var(--font-mono);
}

.frequency-value {
  font-size: 2.5rem;
  color: var(--color-accent-green);
  font-family: var(--font-mono);
  font-weight: 400;
  text-shadow: 0 0 10px var(--color-accent-green);
  letter-spacing: 2px;
  cursor: pointer;
  padding: 8px 12px;
  border-radius: 6px;
  transition: all 0.3s ease;
  user-select: none;
}

.frequency-value:hover {
  background: rgba(0, 229, 255, 0.1);
  transform: scale(1.02);
  text-shadow: 0 0 15px var(--color-accent-green);
}

.frequency-unit {
  font-size: 1.2rem;
  color: var(--color-accent-green);
  font-family: var(--font-mono);
}

.frequency-slider-container {
  position: relative;
  margin-bottom: var(--spacing-md);
}

.frequency-slider {
  width: 100%;
  height: 6px;
  background: var(--color-border);
  outline: none;
  border-radius: 3px;
  -webkit-appearance: none;
  appearance: none;
}

.frequency-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--color-accent-cyan);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 10px var(--color-accent-cyan);
  transition: all var(--transition-fast);
}

.frequency-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 0 15px var(--color-accent-cyan);
}

.frequency-slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  background: var(--color-accent-cyan);
  border-radius: 50%;
  cursor: pointer;
  border: none;
  box-shadow: 0 0 10px var(--color-accent-cyan);
}

.frequency-scale {
  display: flex;
  justify-content: space-between;
  margin-top: var(--spacing-xs);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
}

.frequency-buttons {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
}

.freq-btn {
  background: transparent;
  border: 1px solid var(--color-accent-cyan);
  color: var(--color-accent-cyan);
  padding: var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.freq-btn:hover {
  background: var(--color-accent-cyan);
  color: var(--color-primary-bg);
  box-shadow: var(--shadow-glow-cyan);
  transform: scale(1.05);
}

.freq-btn:active {
  transform: scale(0.95);
}

/* ========== Audio Player ========== */
.audio-player {
  background: var(--color-primary-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.audio-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.audio-btn {
  background: transparent;
  border: 2px solid var(--color-accent-green);
  color: var(--color-accent-green);
  padding: var(--spacing-md);
  border-radius: 50%;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 60px;
  height: 60px;
}

.play-pause-btn {
  width: 80px;
  height: 80px;
  border-width: 3px;
}

.audio-btn:hover {
  background: var(--color-accent-green);
  color: var(--color-primary-bg);
  box-shadow: var(--shadow-glow-green);
  transform: scale(1.05);
}

.audio-btn:active {
  transform: scale(0.95);
}

.audio-btn.playing {
  background: var(--color-accent-green);
  color: var(--color-primary-bg);
  box-shadow: var(--shadow-glow-green);
}

.volume-control {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.volume-icon {
  color: var(--color-text-secondary);
  flex-shrink: 0;
}

.volume-slider {
  flex: 1;
  height: 4px;
  background: var(--color-border);
  outline: none;
  border-radius: 2px;
  -webkit-appearance: none;
  appearance: none;
}

.volume-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  background: var(--color-accent-cyan);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 8px var(--color-accent-cyan);
}

.volume-slider::-moz-range-thumb {
  width: 16px;
  height: 16px;
  background: var(--color-accent-cyan);
  border-radius: 50%;
  cursor: pointer;
  border: none;
  box-shadow: 0 0 8px var(--color-accent-cyan);
}

.volume-value {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  min-width: 40px;
  text-align: right;
}

.audio-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.audio-status {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

.audio-time {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-accent-cyan);
}

/* ========== Mode Selection ========== */
.mode-selection {
  background: var(--color-primary-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
}

.mode-label {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

.mode-buttons {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
}

.mode-btn {
  background: transparent;
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  min-width: 50px;
}

.mode-btn:hover {
  border-color: var(--color-accent-cyan);
  color: var(--color-accent-cyan);
}

.mode-btn.active {
  background: var(--color-accent-cyan);
  border-color: var(--color-accent-cyan);
  color: var(--color-primary-bg);
  box-shadow: 0 0 10px rgba(0, 229, 255, 0.3);
}

/* ========== Modal ========== */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(5px);
  z-index: 1000;
  animation: fadeIn var(--transition-normal);
}

.modal.show {
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-content {
  background: var(--color-secondary-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  max-width: 500px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-card);
}

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

.modal-header h3 {
  color: var(--color-accent-cyan);
  margin: 0;
}

.modal-close {
  background: transparent;
  border: none;
  color: var(--color-text-secondary);
  cursor: pointer;
  padding: var(--spacing-xs);
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
}

.modal-close:hover {
  color: var(--color-text-primary);
  background: var(--color-hover);
}

.modal-body {
  padding: var(--spacing-lg);
}

.modal-body p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
}

.modal-body ul {
  margin: var(--spacing-md) 0;
  padding-left: var(--spacing-lg);
}

.modal-body li {
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-secondary);
}

.modal-body strong {
  color: var(--color-text-primary);
}

.modal-info {
  background: rgba(0, 229, 255, 0.05);
  border: 1px solid rgba(0, 229, 255, 0.2);
  border-radius: var(--border-radius);
  padding: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.modal-info p {
  margin-bottom: var(--spacing-sm);
  font-size: 0.9rem;
}

.modal-info p:last-child {
  margin-bottom: 0;
}

/* ========== Responsive Design ========== */
@media (max-width: 1024px) {
  .grid-layout {
    grid-template-columns: 300px 1fr;
    gap: var(--spacing-md);
  }
  
  .title-main {
    font-size: 2rem;
  }
  
  .frequency-value {
    font-size: 2rem;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  .grid-layout {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }
  
  .station-list-panel {
    order: 2;
  }
  
  .control-panel {
    order: 1;
    position: static;
  }
  
  .header .container {
    flex-direction: column;
    gap: var(--spacing-sm);
    text-align: center;
  }
  
  .title-main {
    font-size: 1.8rem;
  }
  
  .frequency-value {
    font-size: 1.8rem;
  }
  
  .station-details-info {
    grid-template-columns: 1fr;
  }
  
  .audio-controls {
    flex-wrap: wrap;
  }
  
  .mode-buttons {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  :root {
    --spacing-md: 12px;
    --spacing-lg: 18px;
    --spacing-xl: 24px;
  }
  
  .title-main {
    font-size: 1.5rem;
  }
  
  .frequency-value {
    font-size: 1.5rem;
  }
  
  .station-list-panel,
  .control-panel {
    padding: var(--spacing-md);
  }
  
  .play-pause-btn {
    width: 60px;
    height: 60px;
  }
  
  .audio-btn {
    width: 50px;
    height: 50px;
  }
}

/* ========== Animations ========== */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.station-item {
  animation: slideUp 0.3s ease forwards;
}

.station-item:nth-child(n) {
  animation-delay: calc(var(--delay, 0) * 0.05s);
}

/* ========== Loading States ========== */
.loading-screen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--color-primary-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition: opacity var(--transition-slow);
}

.loading-screen.fade-out {
  opacity: 0;
  pointer-events: none;
}

.loading-spinner {
  width: 50px;
  height: 50px;
  border: 3px solid var(--color-border);
  border-top: 3px solid var(--color-accent-cyan);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* ========== Utilities ========== */
.hidden {
  display: none !important;
}

.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;
}

/* ========== Print Styles ========== */
@media print {
  .header-button,
  .audio-player,
  .spectrum-container,
  .frequency-control,
  .mode-selection {
    display: none;
  }
  
  body {
    background: white;
    color: black;
  }
  
  .container {
    max-width: none;
    padding: 0;
  }
}