:root {
    --bg-primary: #0a0a0a;
    --bg-secondary: #141414;
    --bg-tertiary: #1a1a1a;
    --bg-hover: #242424;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-tertiary: #606060;
    --accent: #ff3333;
    --accent-hover: #ff5555;
    --border: #2a2a2a;
    --shadow: rgba(0, 0, 0, 0.5);
    --gradient-start: #ff3333;
    --gradient-end: #cc0000;
    --transition-fast: 150ms;
    --transition-normal: 300ms;
    --transition-slow: 500ms;
    --radius-small: 4px;
    --radius-medium: 8px;
    --radius-large: 12px;
    --header-height: 60px;
    --player-height-mobile: 200px;
    --player-height-desktop: 250px;
}

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

html {
    font-size: 16px;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.app-title {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.mode-toggle {
    width: 48px;
    height: 48px;
    border: none;
    background: var(--bg-tertiary);
    border-radius: var(--radius-medium);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast) cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.mode-toggle:hover {
    background: var(--bg-hover);
    transform: scale(1.05);
}

.mode-toggle:active {
    transform: scale(0.95);
}

.mode-toggle svg {
    width: 24px;
    height: 24px;
    transition: all var(--transition-normal) cubic-bezier(0.4, 0, 0.2, 1);
    position: absolute;
}

.mode-toggle .icon-video {
    opacity: 0;
    transform: rotate(-180deg) scale(0.5);
}

body[data-mode="video"] .mode-toggle .icon-audio {
    opacity: 0;
    transform: rotate(180deg) scale(0.5);
}

body[data-mode="video"] .mode-toggle .icon-video {
    opacity: 1;
    transform: rotate(0) scale(1);
}

.main-content {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
    width: 100%;
}

.album-section {
    margin-bottom: 3rem;
}

.album-header {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.album-cover {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    border-radius: var(--radius-large);
    box-shadow: 0 8px 32px var(--shadow);
    transition: transform var(--transition-normal) cubic-bezier(0.4, 0, 0.2, 1);
}

.album-cover:hover {
    transform: scale(1.02);
}

.album-info {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 0.5rem;
}

.album-title {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.1;
}

.album-artist {
    font-size: 1.25rem;
    color: var(--text-secondary);
}

.album-year {
    font-size: 1rem;
    color: var(--text-tertiary);
}

.download-album,
.download-video {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    border: none;
    border-radius: var(--radius-medium);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast) cubic-bezier(0.4, 0, 0.2, 1);
    margin-top: 1rem;
}

.download-album:hover,
.download-video:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(255, 51, 51, 0.4);
}

.download-album:active,
.download-video:active {
    transform: translateY(0);
}

.download-album svg,
.download-video svg {
    width: 18px;
    height: 18px;
}

.playlist {
    background: var(--bg-secondary);
    border-radius: var(--radius-large);
    padding: 1.5rem;
}

.playlist-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.tracks-container {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.track-item {
    display: grid;
    grid-template-columns: 40px 40px 1fr auto auto;
    align-items: center;
    gap: 1rem;
    padding: 0.75rem;
    border-radius: var(--radius-medium);
    cursor: pointer;
    transition: all var(--transition-fast) cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.track-item:hover {
    background: var(--bg-hover);
}

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

.track-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 60%;
    background: var(--accent);
    border-radius: 0 2px 2px 0;
}

.track-item.loading .track-number {
    display: none;
}

.track-item.loading::after {
    content: '';
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    border: 2px solid var(--text-tertiary);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.track-number {
    text-align: center;
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.track-item.active .track-number {
    color: var(--accent);
    font-weight: 600;
}

.track-cover {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-small);
    object-fit: cover;
}

.track-info {
    display: flex;
    flex-direction: column;
    gap: 0.125rem;
    min-width: 0;
}

.track-title {
    font-size: 0.9375rem;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.track-artist {
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

.track-play-audio,
.track-play-video {
    width: 36px;
    height: 36px;
    border: none;
    background: var(--bg-tertiary);
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast) cubic-bezier(0.4, 0, 0.2, 1);
}

.track-play-audio:hover,
.track-play-video:hover {
    background: var(--accent);
    transform: scale(1.1);
}

.track-play-audio svg,
.track-play-video svg {
    width: 16px;
    height: 16px;
    color: var(--text-primary);
}

.player-section {
    position: sticky;
    bottom: 0;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.audio-player,
.video-player {
    display: none;
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem 1rem;
}

body[data-mode="audio"] .audio-player {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 1.5rem;
}

body[data-mode="video"] .video-player {
    display: block;
}

.player-cover {
    width: var(--player-height-mobile);
    height: var(--player-height-mobile);
    position: relative;
    overflow: hidden;
    border-radius: var(--radius-large);
    box-shadow: 0 4px 16px var(--shadow);
}

.current-cover {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.player-content {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

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

.current-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.current-artist {
    font-size: 1rem;
    color: var(--text-secondary);
}

.lyrics-display {
    height: 80px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    position: relative;
    overflow: hidden;
}

.lyrics-line {
    text-align: center;
    transition: all var(--transition-slow) cubic-bezier(0.4, 0, 0.2, 1);
}

.lyrics-line.prev,
.lyrics-line.next {
    color: var(--text-tertiary);
    font-size: 0.875rem;
    opacity: 0.5;
}

.lyrics-line.current {
    color: var(--text-primary);
    font-size: 1.125rem;
    font-weight: 500;
    opacity: 1;
    transform: scale(1.05);
}

.player-controls {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.progress-container {
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: 1rem;
}

.time-current,
.time-total {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    font-variant-numeric: tabular-nums;
}

.progress-bar {
    height: 4px;
    background: var(--bg-tertiary);
    border-radius: 2px;
    position: relative;
    cursor: pointer;
}

.progress-filled {
    height: 100%;
    background: var(--accent);
    border-radius: 2px;
    width: 0%;
    transition: width var(--transition-fast) linear;
}

.progress-handle {
    position: absolute;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 12px;
    height: 12px;
    background: var(--text-primary);
    border-radius: 50%;
    opacity: 0;
    transition: opacity var(--transition-fast) cubic-bezier(0.4, 0, 0.2, 1);
    cursor: grab;
}

.progress-bar:hover .progress-handle {
    opacity: 1;
}

.progress-handle:active {
    cursor: grabbing;
    transform: translate(-50%, -50%) scale(1.2);
}

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

.control-prev,
.control-next,
.control-play {
    border: none;
    background: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast) cubic-bezier(0.4, 0, 0.2, 1);
}

.control-prev,
.control-next {
    width: 40px;
    height: 40px;
    color: var(--text-secondary);
}

.control-prev:hover,
.control-next:hover {
    color: var(--text-primary);
    transform: scale(1.1);
}

.control-play {
    width: 56px;
    height: 56px;
    background: var(--accent);
    border-radius: 50%;
    color: var(--text-primary);
}

.control-play:hover {
    background: var(--accent-hover);
    transform: scale(1.05);
    box-shadow: 0 4px 16px rgba(255, 51, 51, 0.4);
}

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

.control-play svg {
    width: 24px;
    height: 24px;
}

.control-play .icon-pause {
    display: none;
}

.control-play.playing .icon-play {
    display: none;
}

.control-play.playing .icon-pause {
    display: block;
}

.video-container {
    position: relative;
    width: 100%;
    max-width: 800px;
    margin: 0 auto 1.5rem;
    background: #000;
    border-radius: var(--radius-large);
    overflow: hidden;
    box-shadow: 0 4px 16px var(--shadow);
}

.video-container video {
    width: 100%;
    height: auto;
    display: block;
}

.video-info {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.video-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--text-tertiary);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.player-buffering::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
}

*:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

button:focus-visible {
    outline-offset: 4px;
}

.error-message {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-secondary);
    border: 1px solid var(--accent);
    padding: 1rem 2rem;
    border-radius: var(--radius-medium);
    z-index: 1000;
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        transform: translateX(-50%) translateY(100%);
        opacity: 0;
    }
    to {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }
}

@media (max-width: 768px) {
    .album-header {
        grid-template-columns: 120px 1fr;
        gap: 1rem;
    }
    
    .album-title {
        font-size: 1.75rem;
    }
    
    .album-artist {
        font-size: 1rem;
    }
    
    .track-item {
        grid-template-columns: 30px 30px 1fr auto auto;
        padding: 0.5rem;
        gap: 0.75rem;
    }
    
    .track-cover {
        width: 30px;
        height: 30px;
    }
    
    .track-title {
        font-size: 0.875rem;
    }
    
    .track-artist {
        font-size: 0.75rem;
    }
    
    .track-play-audio,
    .track-play-video {
        width: 32px;
        height: 32px;
    }
    
    body[data-mode="audio"] .audio-player {
        grid-template-columns: 1fr;
    }
    
    .player-cover {
        display: none;
    }
    
    .current-title {
        font-size: 1.125rem;
    }
    
    .current-artist {
        font-size: 0.875rem;
    }
    
    .lyrics-line.current {
        font-size: 1rem;
    }
}

@media (min-width: 769px) {
    .player-cover {
        width: var(--player-height-desktop);
        height: var(--player-height-desktop);
    }
    
    body[data-mode="audio"] .audio-player {
        grid-template-columns: var(--player-height-desktop) 1fr;
    }
}

@media (hover: none) {
    .track-item:active {
        background: var(--bg-hover);
    }
    
    .progress-handle {
        opacity: 1;
        width: 16px;
        height: 16px;
    }
}

@supports (backdrop-filter: blur(20px)) or (-webkit-backdrop-filter: blur(20px)) {
    .header,
    .player-section {
        background: rgba(20, 20, 20, 0.8);
    }
}