:root {
  --bg-dark: #0f172a;
  --bg-gradient-start: #0f172a;
  --bg-gradient-end: #1e293b;
  --primary: #8b5cf6;
  --primary-glow: rgba(139, 92, 246, 0.5);
  --secondary: #ec4899;
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --font-family: 'Outfit', sans-serif;
  --radius-lg: 16px;
  --radius-md: 8px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-family);
  background: radial-gradient(circle at top left, var(--bg-gradient-end), var(--bg-dark));
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  overflow-x: hidden;
}

#app {
  width: 100%;
  max-width: 800px;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

/* Top Navigation Bar */
.top-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.25rem;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  margin-bottom: 0.5rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.nav-brand .brand-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--primary);
  text-decoration: none;
  font-weight: 700;
  font-size: 1.15rem;
}

.nav-brand .brand-link:hover {
  opacity: 0.9;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--glass-border);
  font-family: inherit;
}

.nav-btn:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.25);
}

.nav-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  box-shadow: 0 0 12px var(--primary-glow);
}

.nav-btn.admin-btn {
  background: linear-gradient(135deg, rgba(139, 92, 246, 0.3), rgba(236, 72, 153, 0.3));
  border-color: var(--primary);
  color: #fff;
}

.nav-btn.admin-btn:hover {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  box-shadow: 0 0 14px rgba(236, 72, 153, 0.4);
}

.auth-username {
  font-size: 0.85rem;
  color: var(--secondary);
  font-weight: 600;
}

.nav-btn.logout-btn {
  background: rgba(239, 68, 68, 0.15) !important;
  border-color: rgba(239, 68, 68, 0.3) !important;
  color: #fca5a5 !important;
}

.nav-btn.logout-btn:hover {
  background: #ef4444 !important;
  color: #fff !important;
}

/* Header */
header {
  text-align: center;
  margin-bottom: 2rem;
  animation: fadeInDown 0.8s ease-out;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
  color: var(--primary);
}

.logo h1 {
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, #fff, #94a3b8);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  letter-spacing: -0.02em;
}

input[type=range] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
}

.subtitle {
  color: var(--text-muted);
  font-weight: 300;
  font-size: 1.1rem;
}

/* Glass Panel */
.glass-panel {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

/* Visualizer */
.visualizer-container {
  width: 100%;
  height: 120px;
  /* Compact height */
  margin-bottom: 1.5rem;
  background: rgba(0, 0, 0, 0.2);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--glass-border);
}

canvas#visualizer {
  width: 100%;
  height: 100%;
  display: block;
}

/* Auth Buttons */
.btn-small {
  padding: 0.5rem 1rem;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: white;
  text-decoration: none;
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition);
}

.btn-small:hover {
  background: var(--primary);
  border-color: var(--primary);
}

.hidden {
  display: none !important;
}

/* Character Filter */
.char-filter {
  display: flex;
  gap: 0.25rem;
  overflow-x: auto;
  padding: 0.5rem 0;
  margin-bottom: 0.5rem;
  scrollbar-width: thin;
}

.filter-btn {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  border-radius: 4px;
  color: var(--secondary);
  font-size: 0.75rem;
  padding: 0.25rem 0.5rem;
  cursor: pointer;
  white-space: nowrap;
}

.filter-btn:hover,
.filter-btn.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* Library Section */
.library-container {
  padding: 1.5rem;
  margin-bottom: 2rem;
  height: 450px;
  /* Increased height for header + filter + list */
  display: flex;
  flex-direction: column;
}

.library-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.library-container h3 {
  margin: 0;
  font-weight: 500;
  color: var(--secondary);
}

.search-box {
  position: relative;
  width: 200px;
}

.search-box svg {
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  color: rgba(255, 255, 255, 0.4);
  pointer-events: none;
}

.search-box input {
  width: 100%;
  padding: 0.5rem 0.5rem 0.5rem 2.2rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  color: var(--text);
  font-size: 0.9rem;
  outline: none;
  transition: var(--transition);
}

.search-box input:focus {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--primary);
}

.song-list {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.song-item {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md);
  padding: 1rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.song-item:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateX(5px);
}

.song-item.active {
  border-color: var(--primary);
  background: rgba(100, 108, 255, 0.1);
}

.song-name {
  font-weight: 500;
}

.song-play-icon {
  opacity: 0;
  transition: var(--transition);
}

.song-item:hover .song-play-icon,
.song-item.active .song-play-icon {
  opacity: 1;
}

#omr-loading {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 1rem;
  color: var(--secondary);
  font-weight: 500;
}

.hidden {
  display: none !important;
}

.upload-section:hover,
.upload-section.dragover {
  border-color: var(--primary);
  background: rgba(139, 92, 246, 0.05);
  transform: translateY(-2px);
}

.upload-input {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
}

.upload-icon {
  margin-bottom: 1rem;
  color: var(--text-muted);
  transition: var(--transition);
}

.upload-section:hover .upload-icon {
  color: var(--primary);
  transform: scale(1.1);
}

#file-input {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  opacity: 0;
  cursor: pointer;
}

.file-name {
  margin-top: 1rem;
  font-weight: 500;
  color: var(--primary);
  min-height: 1.5rem;
}

/* Controls */
.controls-wrapper {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  opacity: 0.6;
  pointer-events: none;
  transition: var(--transition);
  filter: grayscale(0.5);
}

.controls-wrapper.active {
  opacity: 1;
  pointer-events: all;
  filter: none;
}

.control-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.control-group label {
  display: block;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
  font-weight: 600;
}

/* Select */
.select-wrapper {
  position: relative;
}

select {
  width: 100%;
  padding: 0.75rem 1rem;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-family: inherit;
  font-size: 1rem;
  appearance: none;
  cursor: pointer;
  transition: var(--transition);
}

select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px var(--primary-glow);
}

.select-arrow {
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
  font-size: 0.8rem;
}

/* Range Input */
.range-wrapper {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: rgba(0, 0, 0, 0.2);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--glass-border);
}

.range-value {
  min-width: 3rem;
  font-variant-numeric: tabular-nums;
  font-size: 0.9rem;
  color: var(--secondary);
  font-weight: 600;
}

input[type="range"] {
  width: 100%;
  height: 4px;
  background: var(--glass-border);
  border-radius: 2px;
  appearance: none;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--secondary);
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 0 10px rgba(236, 72, 153, 0.3);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

/* Number Input (Stepper) */
.number-wrapper {
  display: flex;
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--radius-md);
  border: 1px solid var(--glass-border);
  overflow: hidden;
}

.step-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 0.5rem 1rem;
  cursor: pointer;
  font-size: 1.2rem;
  transition: var(--transition);
}

.step-btn:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
}

input[type="number"] {
  background: transparent;
  border: none;
  color: var(--text-main);
  text-align: center;
  width: 3rem;
  font-family: inherit;
  font-weight: 600;
  -moz-appearance: textfield;
}

input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* Playback Buttons */
.playback-controls {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 1rem;
}

.control-btn {
  border: none;
  border-radius: 50%;
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.control-btn.play {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  box-shadow: 0 0 20px var(--primary-glow);
}

.control-btn.play:hover {
  transform: scale(1.05);
  box-shadow: 0 0 30px var(--primary-glow);
}

.control-btn.stop {
  width: 48px;
  height: 48px;
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-main);
  margin-top: 8px;
  /* Alignment fix */
}

.control-btn.stop:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* Status Bar */
.status-bar {
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-muted);
  min-height: 1.2rem;
  margin-top: 0.5rem;
}

footer {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8rem;
  padding: 2rem 0;
  opacity: 0.5;
}

/* Animations */
@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 600px) {
  .control-row {
    grid-template-columns: 1fr;
  }

  #app {
    padding: 1rem;
  }
}