/* ==================== CSS 变量 & 基础样式 ==================== */
:root {
    --bg-primary: #0a0a0a;
    --bg-secondary: #121212;
    --bg-surface: #1a1a1a;
    --bg-surface-hover: #242424;
    --bg-surface-active: #2a2a2a;
    --bg-player: rgba(18, 18, 18, 0.85);
    --text-primary: #ffffff;
    --text-secondary: #b3b3b3;
    --text-tertiary: #727272;
    --accent: #1db954;
    --accent-hover: #1ed760;
    --accent-dim: #1a9e47;
    --progress-bg: #4d4d4d;
    --progress-fill: #ffffff;
    --progress-accent: #1db954;
    --border-subtle: rgba(255, 255, 255, 0.06);
    --border-visible: rgba(255, 255, 255, 0.12);
    --shadow-player: 0 -4px 20px rgba(0, 0, 0, 0.5);
    --shadow-cover: 0 4px 16px rgba(0, 0, 0, 0.4);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-full: 50%;
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.4s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    --player-height: 90px;
    --mini-progress-height: 3px;
}

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
    user-select: none;
    -webkit-user-select: none;
    -webkit-tap-highlight-color: transparent;
}

#app {
    display: flex;
    flex-direction: column;
    height: 100vh;
    position: relative;
}

/* ==================== 播放列表区域 ==================== */
#playlist-area {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding-bottom: calc(var(--player-height) + 24px);
    scroll-behavior: smooth;
}

#playlist-area::-webkit-scrollbar {
    width: 6px;
}
#playlist-area::-webkit-scrollbar-track {
    background: transparent;
}
#playlist-area::-webkit-scrollbar-thumb {
    background: var(--progress-bg);
    border-radius: 3px;
}
#playlist-area::-webkit-scrollbar-thumb:hover {
    background: #6a6a6a;
}

/* 表头 */
#playlist-header {
    display: flex;
    align-items: center;
    padding: 16px 24px 10px 24px;
    border-bottom: 1px solid var(--border-subtle);
    position: sticky;
    top: 0;
    z-index: 10;
    background: rgba(10, 10, 10, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.header-col {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-tertiary);
}

.col-index {
    width: 40px;
    text-align: center;
    flex-shrink: 0;
}
.col-cover {
    width: 48px;
    flex-shrink: 0;
    margin-left: 8px;
}
.col-info {
    flex: 1;
    padding-left: 12px;
    min-width: 0;
}
.col-duration {
    width: 60px;
    text-align: right;
    flex-shrink: 0;
    padding-right: 8px;
}

/* 播放列表容器 */
#playlist-container {
    padding: 4px 16px;
}

/* 单首歌曲行 */
.playlist-row {
    display: flex;
    align-items: center;
    padding: 8px 8px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background-color var(--transition-fast);
    gap: 0;
    position: relative;
    margin: 1px 0;
}

.playlist-row:hover {
    background-color: var(--bg-surface-hover);
}

.playlist-row:active {
    background-color: var(--bg-surface-active);
}

.playlist-row.active {
    background-color: rgba(29, 185, 84, 0.1);
    border-radius: var(--radius-sm);
}

.playlist-row.active .row-title {
    color: var(--accent);
}

.playlist-row.active .row-index {
    color: var(--accent);
}

/* 序号 */
.row-index {
    width: 40px;
    text-align: center;
    flex-shrink: 0;
    font-size: 0.9rem;
    color: var(--text-tertiary);
    font-variant-numeric: tabular-nums;
    font-family: 'SF Mono', 'Consolas', 'Monaco', monospace;
    transition: color var(--transition-fast);
}

.playlist-row.active .row-index .index-number {
    display: none;
}
.playlist-row .row-index .icon-playing {
    display: none;
}
.playlist-row.active .row-index .icon-playing {
    display: inline;
    animation: equalizer 0.6s ease-in-out infinite alternate;
}
.playlist-row.active .row-index .icon-playing:nth-child(2) {
    animation-delay: 0.15s;
}
.playlist-row.active .row-index .icon-playing:nth-child(3) {
    animation-delay: 0.3s;
}

@keyframes equalizer {
    0% {
        transform: scaleY(0.4);
    }
    100% {
        transform: scaleY(1);
    }
}

.icon-playing-bar {
    display: inline-block;
    width: 3px;
    height: 14px;
    background-color: var(--accent);
    border-radius: 2px;
    margin: 0 1px;
    vertical-align: middle;
    transform-origin: center bottom;
}

/* 封面缩略图 */
.row-cover {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    object-fit: cover;
    flex-shrink: 0;
    margin-left: 8px;
    background: var(--bg-surface);
    transition: opacity var(--transition-fast);
}

.row-cover-placeholder {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    flex-shrink: 0;
    margin-left: 8px;
    background: linear-gradient(135deg, #2a2a2a 0%, #1a1a1a 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-tertiary);
}

/* 歌曲信息 */
.row-info {
    flex: 1;
    padding-left: 12px;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.row-title {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    transition: color var(--transition-fast);
    line-height: 1.3;
}

.row-artist {
    font-size: 0.8rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1.3;
}

/* 时长 */
.row-duration {
    width: 60px;
    text-align: right;
    flex-shrink: 0;
    font-size: 0.85rem;
    color: var(--text-tertiary);
    font-variant-numeric: tabular-nums;
    font-family: 'SF Mono', 'Consolas', 'Monaco', monospace;
    padding-right: 8px;
}

/* 空状态 */
#playlist-empty {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 80px 20px;
    color: var(--text-tertiary);
    text-align: center;
}
#playlist-empty svg {
    margin-bottom: 16px;
    opacity: 0.5;
}
#playlist-empty p {
    font-size: 1.1rem;
    margin-bottom: 4px;
    color: var(--text-secondary);
}
#playlist-empty span {
    font-size: 0.85rem;
}
#playlist-area.empty #playlist-empty {
    display: flex;
}
#playlist-area.empty #playlist-header,
#playlist-area.empty #playlist-container {
    display: none;
}

/* ==================== 底部播放器 ==================== */
#player {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--player-height);
    background: var(--bg-player);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-top: 1px solid var(--border-visible);
    box-shadow: var(--shadow-player);
    z-index: 100;
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-normal);
}

/* 迷你进度条 */
.mini-progress {
    height: var(--mini-progress-height);
    background: var(--progress-bg);
    cursor: pointer;
    position: relative;
    flex-shrink: 0;
    transition: height var(--transition-fast);
}
.mini-progress:hover {
    height: 5px;
}
.mini-progress-fill {
    height: 100%;
    background: var(--progress-accent);
    border-radius: 0 2px 2px 0;
    transition: width 0.05s linear;
    pointer-events: none;
    position: relative;
}
.mini-progress-fill::after {
    content: '';
    position: absolute;
    right: -5px;
    top: 50%;
    transform: translateY(-50%);
    width: 10px;
    height: 10px;
    background: var(--accent);
    border-radius: var(--radius-full);
    opacity: 0;
    transition: opacity var(--transition-fast);
    box-shadow: 0 0 6px rgba(29, 185, 84, 0.5);
}
.mini-progress:hover .mini-progress-fill::after {
    opacity: 1;
}

/* 播放器内部布局 */
#player-inner {
    display: flex;
    align-items: center;
    height: calc(var(--player-height) - var(--mini-progress-height));
    padding: 0 16px;
    gap: 16px;
}

/* 左侧 */
.player-left {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 260px;
    flex-shrink: 0;
    min-width: 180px;
}

.player-cover-wrapper {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-sm);
    overflow: hidden;
    flex-shrink: 0;
    position: relative;
    box-shadow: var(--shadow-cover);
}

.player-cover-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.player-cover-placeholder {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, #3a3a3a 0%, #1a1a1a 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-tertiary);
    pointer-events: none;
}

.player-cover-img[src=""],
.player-cover-img[src="covers/"] {
    display: none;
}
.player-cover-img[src=""]~.player-cover-placeholder,
.player-cover-img[src="covers/"]~.player-cover-placeholder {
    display: flex;
}
.player-cover-img:not([src=""])~.player-cover-placeholder {
    display: none;
}

.player-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 0;
    flex: 1;
}

.player-title {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1.3;
}

.player-artist {
    font-size: 0.75rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1.3;
}

#btn-like {
    flex-shrink: 0;
    color: var(--text-secondary);
    transition: color var(--transition-fast), transform var(--transition-fast);
}
#btn-like:hover {
    color: var(--text-primary);
    transform: scale(1.1);
}
#btn-like.liked {
    color: #e74c3c;
}
#btn-like.liked svg {
    fill: #e74c3c;
    stroke: #e74c3c;
}

/* 中间 */
.player-center {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    min-width: 0;
    max-width: 600px;
    margin: 0 auto;
}

.player-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.btn-control {
    color: var(--text-secondary);
    transition: color var(--transition-fast), transform var(--transition-fast);
}
.btn-control:hover {
    color: var(--text-primary);
    transform: scale(1.08);
}
.btn-control:active {
    transform: scale(0.94);
}

.btn-play {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background-color: var(--text-primary);
    color: var(--bg-primary);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
    flex-shrink: 0;
}
.btn-play:hover {
    background-color: var(--accent-hover);
    transform: scale(1.06);
    box-shadow: 0 4px 16px rgba(29, 185, 84, 0.4);
    color: #000;
}
.btn-play:active {
    transform: scale(0.94);
    transition: transform 0.1s ease;
}

/* 进度条容器 */
.progress-container {
    display: flex;
    align-items: center;
    gap: 10px;
    width: 100%;
    max-width: 500px;
}

.time-label {
    font-size: 0.7rem;
    color: var(--text-tertiary);
    font-variant-numeric: tabular-nums;
    font-family: 'SF Mono', 'Consolas', 'Monaco', monospace;
    flex-shrink: 0;
    min-width: 34px;
    text-align: center;
    letter-spacing: 0.02em;
}

.progress-slider-wrapper {
    flex: 1;
    position: relative;
    height: 20px;
    display: flex;
    align-items: center;
}

.progress-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 4px;
    border-radius: 2px;
    background: transparent;
    cursor: pointer;
    position: relative;
    z-index: 2;
    outline: none;
}

.progress-slider::-webkit-slider-runnable-track {
    -webkit-appearance: none;
    height: 4px;
    border-radius: 2px;
    background: var(--progress-bg);
    border: none;
}

.progress-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 13px;
    height: 13px;
    border-radius: var(--radius-full);
    background: var(--progress-fill);
    border: none;
    cursor: pointer;
    margin-top: -4.5px;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    opacity: 0;
}

.progress-slider:hover::-webkit-slider-thumb,
.progress-slider:active::-webkit-slider-thumb {
    opacity: 1;
    transform: scale(1.2);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
}

.progress-slider::-moz-range-track {
    height: 4px;
    border-radius: 2px;
    background: var(--progress-bg);
    border: none;
}

.progress-slider::-moz-range-thumb {
    width: 13px;
    height: 13px;
    border-radius: var(--radius-full);
    background: var(--progress-fill);
    border: none;
    cursor: pointer;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
    opacity: 0;
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.progress-slider:hover::-moz-range-thumb,
.progress-slider:active::-moz-range-thumb {
    opacity: 1;
    transform: scale(1.2);
}

/* 进度条背景轨道覆盖层（用于显示已播放部分） */
.progress-track-bg {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    height: 4px;
    border-radius: 2px;
    background: var(--progress-fill);
    pointer-events: none;
    z-index: 1;
    transition: width 0.05s linear;
}

.progress-container:hover .progress-track-bg {
    background: var(--progress-accent);
}

/* 右侧 */
.player-right {
    display: flex;
    align-items: center;
    gap: 8px;
    width: 200px;
    flex-shrink: 0;
    justify-content: flex-end;
}

.volume-slider-wrapper {
    width: 100px;
    height: 20px;
    display: flex;
    align-items: center;
}

.volume-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 4px;
    border-radius: 2px;
    background: transparent;
    cursor: pointer;
    outline: none;
}

.volume-slider::-webkit-slider-runnable-track {
    -webkit-appearance: none;
    height: 4px;
    border-radius: 2px;
    background: var(--progress-bg);
    border: none;
}

.volume-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 12px;
    height: 12px;
    border-radius: var(--radius-full);
    background: var(--progress-fill);
    border: none;
    cursor: pointer;
    margin-top: -4px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
    opacity: 0;
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.volume-slider:hover::-webkit-slider-thumb,
.volume-slider:active::-webkit-slider-thumb {
    opacity: 1;
    transform: scale(1.2);
}

.volume-slider::-moz-range-track {
    height: 4px;
    border-radius: 2px;
    background: var(--progress-bg);
    border: none;
}

.volume-slider::-moz-range-thumb {
    width: 12px;
    height: 12px;
    border-radius: var(--radius-full);
    background: var(--progress-fill);
    border: none;
    cursor: pointer;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.volume-slider:hover::-moz-range-thumb,
.volume-slider:active::-moz-range-thumb {
    opacity: 1;
}

/* 按钮图标通用样式 */
.btn-icon {
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color var(--transition-fast), transform var(--transition-fast), background-color var(--transition-fast);
    color: var(--text-secondary);
    flex-shrink: 0;
}
.btn-icon:hover {
    color: var(--text-primary);
    background-color: rgba(255, 255, 255, 0.05);
}
.btn-icon:active {
    transform: scale(0.92);
}

/* 随机和循环按钮激活状态 */
.btn-control.active {
    color: var(--accent) !important;
}
.btn-control.active svg {
    stroke: var(--accent);
}

/* ==================== Toast 提示 ==================== */
.toast {
    position: fixed;
    bottom: calc(var(--player-height) + 20px);
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: var(--bg-surface);
    color: var(--text-primary);
    padding: 10px 20px;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 500;
    pointer-events: none;
    opacity: 0;
    transition: opacity var(--transition-normal), transform var(--transition-normal);
    z-index: 200;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
    border: 1px solid var(--border-visible);
    white-space: nowrap;
}
.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 768px) {
    #player-inner {
        gap: 8px;
        padding: 0 10px;
    }
    .player-left {
        width: auto;
        min-width: 120px;
        gap: 8px;
    }
    .player-cover-wrapper {
        width: 44px;
        height: 44px;
    }
    .player-title {
        font-size: 0.8rem;
    }
    .player-artist {
        font-size: 0.7rem;
    }
    #btn-like {
        display: none;
    }
    .player-center {
        gap: 4px;
    }
    .player-controls {
        gap: 4px;
    }
    .btn-play {
        width: 34px;
        height: 34px;
    }
    .btn-play svg {
        width: 22px;
        height: 22px;
    }
    .progress-container {
        gap: 4px;
    }
    .time-label {
        font-size: 0.65rem;
        min-width: 26px;
    }
    .player-right {
        width: auto;
        gap: 4px;
    }
    .volume-slider-wrapper {
        width: 60px;
    }
    .col-duration,
    .row-duration {
        width: 44px;
        font-size: 0.75rem;
    }
    #playlist-header {
        padding: 12px 12px 8px 12px;
    }
    #playlist-container {
        padding: 2px 8px;
    }
    .row-cover,
    .row-cover-placeholder {
        width: 34px;
        height: 34px;
    }
    .col-cover {
        width: 38px;
    }
    .row-title {
        font-size: 0.85rem;
    }
    .row-artist {
        font-size: 0.72rem;
    }
}

@media (max-width: 480px) {
    :root {
        --player-height: 80px;
    }
    .player-cover-wrapper {
        width: 36px;
        height: 36px;
    }
    .player-info {
        gap: 0;
    }
    .player-title {
        font-size: 0.75rem;
    }
    .player-artist {
        font-size: 0.65rem;
    }
    .player-right {
        display: none;
    }
    .player-left {
        min-width: 100px;
    }
    .btn-control {
        padding: 4px;
    }
    .btn-play {
        width: 30px;
        height: 30px;
    }
    .btn-play svg {
        width: 18px;
        height: 18px;
    }
    #playlist-header {
        padding: 10px 10px 6px 10px;
    }
    .col-index {
        width: 28px;
        font-size: 0.7rem;
    }
    .row-index {
        width: 28px;
        font-size: 0.75rem;
    }
    .col-cover {
        width: 32px;
    }
    .row-cover,
    .row-cover-placeholder {
        width: 28px;
        height: 28px;
        margin-left: 4px;
    }
    .col-duration,
    .row-duration {
        width: 36px;
        font-size: 0.7rem;
    }
}