@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

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

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

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

@keyframes soundWave {
    0%, 100% {
        height: 4px;
    }
    50% {
        height: 16px;
    }
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

@keyframes heartBeat {
    0% {
        transform: scale(1);
    }
    15% {
        transform: scale(1.3);
    }
    30% {
        transform: scale(1);
    }
    45% {
        transform: scale(1.15);
    }
    60% {
        transform: scale(1);
    }
}

.playing-icon {
    display: flex;
    align-items: flex-end;
    gap: 2px;
    height: 16px;
}

.playing-icon .bar {
    width: 3px;
    background: var(--accent-primary);
    border-radius: 1px;
    animation: soundWave 0.8s ease-in-out infinite;
}

.playing-icon .bar:nth-child(1) {
    animation-delay: 0s;
}

.playing-icon .bar:nth-child(2) {
    animation-delay: 0.2s;
}

.playing-icon .bar:nth-child(3) {
    animation-delay: 0.4s;
}

.like-btn.animating svg {
    animation: heartBeat 0.6s ease-in-out;
}

.track-item {
    animation: fadeIn var(--duration-normal) var(--ease-out);
}

.track-item:nth-child(1) { animation-delay: 0ms; }
.track-item:nth-child(2) { animation-delay: 30ms; }
.track-item:nth-child(3) { animation-delay: 60ms; }
.track-item:nth-child(4) { animation-delay: 90ms; }
.track-item:nth-child(5) { animation-delay: 120ms; }
.track-item:nth-child(6) { animation-delay: 150ms; }
.track-item:nth-child(7) { animation-delay: 180ms; }
.track-item:nth-child(8) { animation-delay: 210ms; }
.track-item:nth-child(9) { animation-delay: 240ms; }
.track-item:nth-child(10) { animation-delay: 270ms; }

.header-content {
    animation: fadeInUp var(--duration-slow) var(--ease-out);
}

.nav-item,
.playlist-item {
    transition: all var(--duration-fast) var(--ease-out);
}

.now-playing-cover img {
    transition: transform var(--duration-slower) var(--ease-smooth);
}

@keyframes coverRotate {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

.now-playing-cover.playing img {
    animation: coverRotate 20s linear infinite;
    border-radius: var(--radius-full);
}

.btn-play,
.btn-play-large {
    transition: all var(--duration-fast) var(--ease-bounce);
}

.btn-icon {
    transition: all var(--duration-fast) var(--ease-out);
}

.btn-icon:active {
    transform: scale(0.9);
}

.progress-played,
.volume-fill,
.fullscreen-progress-played,
.fullscreen-volume-fill {
    transition: width 100ms linear;
}

.playlist-cover img,
.track-cover img {
    transition: transform var(--duration-normal) var(--ease-out);
}

.playlist-cover:hover img,
.track-item:hover .track-cover img {
    transform: scale(1.05);
}

.fullscreen-player {
    transition: opacity var(--duration-slow) var(--ease-smooth),
                visibility var(--duration-slow) var(--ease-smooth);
}

.shuffle-btn.active,
.repeat-btn.active {
    color: var(--accent-primary);
    position: relative;
}

.shuffle-btn.active::after,
.repeat-btn.active::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 4px;
    background: var(--accent-primary);
    border-radius: var(--radius-full);
}

/* ============================================
   流光悬停效果系统 - 霓虹呼吸感
   ============================================ */

/* 歌曲列表项 - 柔和背景 */
.track-item {
    transition: background 0.4s ease, box-shadow 0.4s ease;
}

.track-item:hover {
    background: rgba(var(--accent-rgb, 0, 255, 200), 0.06);
    box-shadow: inset 3px 0 0 rgba(var(--accent-rgb, 0, 255, 200), 0.6);
}

/* 评论项 */
.comment-item {
    transition: background 0.4s ease, box-shadow 0.4s ease;
}

.comment-item:hover {
    background: rgba(255, 255, 255, 0.03);
    box-shadow: inset 2px 0 0 rgba(var(--accent-rgb, 0, 255, 200), 0.4);
}

/* 回复项 */
.reply-item {
    transition: background 0.4s ease, padding-left 0.4s ease;
}

.reply-item:hover {
    background: rgba(255, 255, 255, 0.02);
    padding-left: 14px;
}

/* 卡片通用 - 浮起 + 光晕 */
.playlist-card,
.artist-card,
.artist-album-card {
    position: relative;
    transition: transform 0.6s cubic-bezier(0.23, 1, 0.32, 1),
                box-shadow 0.6s ease;
}

.playlist-card::after,
.artist-card::after,
.artist-album-card::after {
    content: '';
    position: absolute;
    inset: -2px;
    border-radius: inherit;
    background: linear-gradient(135deg,
        rgba(var(--accent-rgb, 0, 255, 200), 0.3),
        transparent 50%,
        rgba(var(--accent-rgb, 0, 255, 200), 0.1)
    );
    opacity: 0;
    z-index: -1;
    filter: blur(8px);
    transition: opacity 0.6s ease;
}

.playlist-card:hover,
.artist-card:hover,
.artist-album-card:hover {
    transform: translateY(-8px);
    box-shadow: 
        0 20px 40px rgba(0, 0, 0, 0.3),
        0 0 30px rgba(var(--accent-rgb, 0, 255, 200), 0.1);
}

.playlist-card:hover::after,
.artist-card:hover::after,
.artist-album-card:hover::after {
    opacity: 1;
}

/* 封面放大 */
.playlist-cover,
.artist-avatar,
.album-card-cover {
    transition: transform 0.8s cubic-bezier(0.23, 1, 0.32, 1);
}

.playlist-card:hover .playlist-cover,
.artist-card:hover .artist-avatar,
.artist-album-card:hover .album-card-cover {
    transform: scale(1.08);
}

/* 侧边栏导航 - 光带滑过 */
.nav-item {
    position: relative;
    overflow: hidden;
}

.nav-item::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
        transparent,
        rgba(var(--accent-rgb, 0, 255, 200), 0.1),
        transparent
    );
    transition: left 0.6s ease;
}

.nav-item:hover::after {
    left: 100%;
}

/* 侧边栏歌单项 */
.playlist-item {
    position: relative;
    overflow: hidden;
}

.playlist-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    width: 2px;
    height: 0;
    background: rgba(var(--accent-rgb, 0, 255, 200), 0.8);
    transform: translateY(-50%);
    transition: height 0.4s cubic-bezier(0.23, 1, 0.32, 1);
}

.playlist-item:hover::before {
    height: 60%;
}

/* 按钮 */
.btn-icon,
.track-action-btn {
    transition: color 0.3s ease, text-shadow 0.3s ease;
}

.btn-icon:hover,
.track-action-btn:hover {
    color: rgba(var(--accent-rgb, 0, 255, 200), 1);
    text-shadow: 0 0 12px rgba(var(--accent-rgb, 0, 255, 200), 0.5);
}

/* 评论区按钮 */
.comment-like-btn,
.comment-reply-to-btn,
.replies-count-btn {
    transition: color 0.3s ease, background 0.3s ease;
}

.comment-like-btn:hover,
.comment-reply-to-btn:hover,
.replies-count-btn:hover {
    color: rgba(var(--accent-rgb, 0, 255, 200), 1);
    background: rgba(var(--accent-rgb, 0, 255, 200), 0.1);
}

/* 主要按钮 */
.btn-primary,
.btn-secondary {
    transition: box-shadow 0.4s ease, filter 0.4s ease;
}

.btn-primary:hover,
.btn-secondary:hover {
    box-shadow: 0 0 20px rgba(var(--accent-rgb, 0, 255, 200), 0.4);
    filter: brightness(1.1);
}

/* 歌词行 - 发光聚焦 */
.lyric-line {
    transition: color 0.4s ease, text-shadow 0.4s ease;
}

.lyric-line:hover:not(.active) {
    color: rgba(255, 255, 255, 0.7);
    text-shadow: 0 0 20px rgba(var(--accent-rgb, 0, 255, 200), 0.3);
}

/* 队列项 */
.queue-item {
    position: relative;
    transition: background 0.4s ease;
}

.queue-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: rgba(var(--accent-rgb, 0, 255, 200), 0.8);
    transform: scaleY(0);
    transition: transform 0.4s cubic-bezier(0.23, 1, 0.32, 1);
}

.queue-item:hover {
    background: rgba(255, 255, 255, 0.04);
}

.queue-item:hover::before {
    transform: scaleY(1);
}

/* 搜索结果项 */
.search-result-item {
    position: relative;
    transition: background 0.4s ease;
}

.search-result-item::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg,
        transparent,
        rgba(var(--accent-rgb, 0, 255, 200), 0.5),
        transparent
    );
    transform: scaleX(0);
    transition: transform 0.5s ease;
}

.search-result-item:hover {
    background: rgba(255, 255, 255, 0.03);
}

.search-result-item:hover::after {
    transform: scaleX(1);
}

/* 工具栏按钮 */
.artists-refresh-btn,
.artists-back-btn {
    transition: background 0.3s ease,
                border-color 0.3s ease,
                color 0.3s ease,
                box-shadow 0.3s ease;
}

.artists-refresh-btn:hover,
.artists-back-btn:hover {
    border-color: rgba(var(--accent-rgb, 0, 255, 200), 0.5);
    box-shadow: 0 0 15px rgba(var(--accent-rgb, 0, 255, 200), 0.2);
}