@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
  --bg-primary: #0a0a0a;
  --bg-secondary: #1a1a1a;
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.7);
  --accent: #6366f1;
  --accent-hover: #818cf8;
  --overlay: rgba(0, 0, 0, 0.5);
  --control-bg: rgba(0, 0, 0, 0.3);
  --control-blur: blur(20px);
  --border-radius: 12px;
  --transition-speed: 0.3s;
}

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

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  height: 100vh;
  width: 100vw;
  overflow: hidden;
  transition: background var(--transition-speed), color var(--transition-speed);
}

.app {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  padding: 0;
}

.header {
  position: relative;
  z-index: 100;
  width: 100%;
  padding: 1.5rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--text-primary);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.menu-btn {
  z-index: 100;
  background: var(--control-bg);
  backdrop-filter: var(--control-blur);
  border: none;
  border-radius: 50%;
  width: 48px;
  height: 48px;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-speed);
  flex-shrink: 0;
  margin-left: auto;
}

.menu-btn:hover {
  background: var(--bg-secondary);
  transform: scale(1.05);
}

.track-list-sidebar {
  position: fixed;
  top: 0;
  right: -400px;
  width: 400px;
  max-width: 90vw;
  height: 100%;
  background: var(--bg-secondary);
  z-index: 101;
  transition: right 0.3s ease;
  display: flex;
  flex-direction: column;
  border-left: 1px solid rgba(255, 255, 255, 0.1);
}

.track-list-sidebar.open {
  right: 0;
}

.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-header h2 {
  font-size: 1.25rem;
  font-weight: 600;
}

.close-sidebar-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-speed);
}

.close-sidebar-btn:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.1);
}

.track-list {
  flex: 1;
  overflow-y: auto;
  padding: 1rem;
}

.track-item {
  display: flex;
  align-items: center;
  padding: 0.75rem;
  margin-bottom: 0.5rem;
  border-radius: 8px;
  cursor: pointer;
  transition: all var(--transition-speed);
}

.track-item:hover {
  background: rgba(255, 255, 255, 0.05);
}

.track-item.active {
  background: var(--accent);
}

.track-item.active .track-item-title {
  color: white;
}

.track-item.active .track-item-artist {
  color: rgba(255, 255, 255, 0.8);
}

.track-item-thumb {
  width: 48px;
  height: 48px;
  border-radius: 8px;
  background-size: cover;
  background-position: center;
  flex-shrink: 0;
  margin-right: 1rem;
}

.track-item-info {
  flex: 1;
  min-width: 0;
}

.track-item-title {
  font-weight: 500;
  margin-bottom: 0.25rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.track-item-artist {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.track-item.playing .track-item-title::after {
  content: ' • Playing';
  font-weight: 400;
  opacity: 0.7;
}

.album-art-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  overflow: hidden;
}

.album-art {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(1.1);
  width: 100%;
  height: 100%;
  background-size: cover;
  background-position: center;
  opacity: 0.8;
  filter: blur(40px) brightness(0.6);
  transition: opacity 0.5s ease, transform 0.5s ease;
  will-change: opacity, transform;
}

.album-art.crossfade-out {
  opacity: 0;
  transform: translate(-50%, -50%) scale(1.15);
}

.album-art.crossfade-in {
  opacity: 0.8;
  transform: translate(-50%, -50%) scale(1.1);
}

.track-info {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 600px;
  margin: auto;
  padding: 2rem;
  animation: fadeUp 0.5s ease;
}

.cover-art {
  width: 300px;
  height: 300px;
  margin: 0 auto 2rem;
  border-radius: 20px;
  background-size: cover;
  background-position: center;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  transition: background-image 0.5s ease;
  will-change: background-image;
}

.track-title {
  font-size: clamp(1.5rem, 5vw, 3rem);
  font-weight: 700;
  margin-bottom: 0.5rem;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.track-artist {
  font-size: clamp(0.875rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  font-weight: 400;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.progress-container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 600px;
  margin-bottom: 2rem;
}

.progress-bar {
  position: relative;
  width: 100%;
  height: 6px;
  background: var(--control-bg);
  border-radius: 3px;
  cursor: pointer;
  overflow: hidden;
  backdrop-filter: var(--control-blur);
  transition: height 0.2s;
}

.progress-bar:hover {
  height: 8px;
}

.progress-fill {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  background: var(--accent);
  border-radius: 3px;
  transition: width 0.1s linear, background var(--transition-speed);
  width: 0%;
  will-change: width;
}

.time-display {
  display: flex;
  justify-content: space-between;
  margin-top: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.controls {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 2rem;
  padding: 1.5rem 3rem;
  background: var(--control-bg);
  backdrop-filter: var(--control-blur);
  border-radius: 50px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
  margin-bottom: 2rem;
}

.control-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-primary);
  padding: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-speed);
  border-radius: 50%;
}

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

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

.play-pause-btn {
  background: var(--text-primary);
  color: var(--bg-primary);
  padding: 1.25rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.play-pause-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.4);
}

.play-pause-btn svg {
  transition: all var(--transition-speed);
}

.prev-btn,
.next-btn {
  opacity: 0.9;
}

.prev-btn:hover,
.next-btn:hover {
  opacity: 1;
}

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

@media (max-width: 640px) {
  .app {
    padding: 1rem;
  }

  .header {
    padding: 1rem 1.5rem;
  }

  .logo {
    font-size: 1.25rem;
  }

  .track-info {
    padding: 1.5rem;
  }

  .cover-art {
    width: 220px;
    height: 220px;
  }

  .controls {
    gap: 1rem;
    padding: 1rem 1.5rem;
  }

  .play-pause-btn {
    padding: 1rem;
  }

  .play-pause-btn svg {
    width: 40px;
    height: 40px;
  }

  .prev-btn svg,
  .next-btn svg {
    width: 28px;
    height: 28px;
  }
}

@media (max-width: 480px) {
  .header {
    padding: 1rem;
  }

  .logo {
    font-size: 1.125rem;
  }

  .menu-btn {
    width: 40px;
    height: 40px;
  }

  .cover-art {
    width: 180px;
    height: 180px;
  }

  .track-title {
    font-size: 1.5rem;
  }

  .track-artist {
    font-size: 0.875rem;
  }

  .controls {
    gap: 0.5rem;
    padding: 0.75rem 1rem;
  }
}