:root {
  --primary-color: #2c3e50;
  --secondary-color: #3498db;
  --text-color: #ecf0f1;
  --hover-color: #2980b9;
  --progress-color: #e74c3c;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #1a2a3d 0%, #1e3c72 100%);
  color: var(--text-color);
  min-height: 100vh;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem;
}

.music-player {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 15px;
  padding: 2rem;
  backdrop-filter: blur(10px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

h1, h2 {
  text-align: center;
  margin-bottom: 1.5rem;
}

.upload-section {
  text-align: center;
  margin-bottom: 2rem;
}

#file-upload {
  display: none;
}

.upload-btn {
  background: var(--secondary-color);
  color: var(--text-color);
  padding: 0.8rem 1.5rem;
  border-radius: 25px;
  cursor: pointer;
  transition: background 0.3s ease;
  display: inline-block;
}

.upload-btn:hover {
  background: var(--hover-color);
}

.playlist {
  margin-bottom: 2rem;
}

.playlist-controls {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

#song-list {
  list-style: none;
  max-height: 300px;
  overflow-y: auto;
}

.song-item {
  padding: 0.8rem;
  margin: 0.5rem 0;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.3s ease;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.song-item:hover {
  background: rgba(255, 255, 255, 0.2);
}

.song-item.active {
  background: var(--secondary-color);
}

.player-controls {
  text-align: center;
}

.song-info {
  margin-bottom: 1rem;
}

#current-song {
  margin-bottom: 1rem;
  font-size: 1.2rem;
}

.progress-container {
  background: rgba(255, 255, 255, 0.1);
  height: 5px;
  border-radius: 3px;
  margin: 1rem 0;
  cursor: pointer;
}

#progress-bar {
  background: var(--progress-color);
  height: 100%;
  border-radius: 3px;
  width: 0;
  transition: width 0.1s linear;
}

.control-buttons {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
}

.control-btn {
  background: transparent;
  border: none;
  color: var(--text-color);
  cursor: pointer;
  font-size: 1.2rem;
  padding: 0.5rem;
  border-radius: 50%;
  transition: transform 0.2s ease;
}

.control-btn:hover {
  transform: scale(1.1);
}

.volume-control {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

#volume-slider {
  width: 100px;
  cursor: pointer;
}

.time-info {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}