/* =========================================
   Variables (カラーテーマ)
========================================= */
:root {
    --bg-base: #0a0a0c;
    --bg-sidebar: #121216;
    --bg-player: #18181c;
    --text-main: #e0e0e0;
    --text-sub: #888888;
    --neon-cyan: #00f0ff;
    --neon-magenta: #ff003c;
    --border-color: #2a2a35;
}

/* =========================================
   Base & Reset
========================================= */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Courier New', Courier, monospace; /* サイバーパンクな等幅フォント */
    background-color: var(--bg-base);
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

.app-container {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* =========================================
   Sidebar & Tags
========================================= */
.sidebar {
    width: 240px;
    background-color: var(--bg-sidebar);
    padding: 20px;
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease;
    z-index: 100;
}

.sidebar h1 {
    color: var(--neon-cyan);
    font-size: 1.2rem;
    margin-bottom: 2rem;
    text-shadow: 0 0 5px rgba(0, 240, 255, 0.5);
}

.sidebar ul { list-style: none; }
.sidebar li a {
    color: var(--text-sub);
    text-decoration: none;
    display: block;
    padding: 10px 0;
    transition: color 0.2s;
}
.sidebar li a:hover { color: var(--text-main); }

/* タグクラウド */
.sidebar-heading {
    color: var(--neon-magenta);
    font-size: 0.8rem;
    margin: 2rem 0 0.5rem;
    letter-spacing: 2px;
}

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.tag-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-sub);
    padding: 4px 8px;
    font-size: 0.75rem;
    border-radius: 4px;
    cursor: pointer;
    font-family: inherit;
    transition: all 0.2s;
}

.tag-btn:hover, .tag-btn.active {
    border-color: var(--neon-cyan);
    color: var(--neon-cyan);
    box-shadow: 0 0 8px rgba(0, 240, 255, 0.3); /* ネオン発光 */
}

.ad-space {
    margin-top: auto;
    border: 1px dashed var(--border-color);
    padding: 10px;
    text-align: center;
    color: var(--text-sub);
}

/* =========================================
   Main Content & Grid
========================================= */
.main-content {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
}

.top-bar {
    display: flex;
    align-items: center;
    margin-bottom: 20px;
}

.menu-btn {
    display: none; /* デフォルト（PC）は非表示 */
    background: transparent;
    border: 1px solid var(--neon-cyan);
    color: var(--neon-cyan);
    font-size: 1.5rem;
    padding: 5px 12px;
    cursor: pointer;
    margin-right: 15px;
    border-radius: 4px;
    box-shadow: 0 0 5px rgba(0, 240, 255, 0.2);
    transition: all 0.2s;
}

.menu-btn:hover {
    background: var(--neon-cyan);
    color: var(--bg-base);
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
    flex: 1;
}

.card {
    background: var(--bg-player);
    padding: 15px;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid transparent;
}

.card:hover {
    transform: translateY(-5px);
    border-color: var(--neon-magenta);
    box-shadow: 0 5px 15px rgba(255, 0, 60, 0.2);
}

.card img {
    width: 100%;
    aspect-ratio: 1 / 1;
    object-fit: cover;
    border-radius: 4px;
    margin-bottom: 10px;
}

/* =========================================
   Footer
========================================= */
footer {
    margin-top: auto;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    text-align: center;
    font-size: 0.8rem;
}
footer nav a { color: var(--text-sub); margin: 0 10px; text-decoration: none; }
footer nav a:hover { color: var(--neon-cyan); }

/* =========================================
   Bottom Player Bar
========================================= */
.player-bar {
    height: 90px;
    background-color: var(--bg-player);
    border-top: 1px solid var(--neon-cyan);
    display: flex;
    align-items: center;
    padding: 0 20px;
    box-shadow: 0 -2px 10px rgba(0, 240, 255, 0.1);
}

.player-cover {
    width: 60px;
    height: 60px;
    object-fit: cover;
    margin-right: 15px;
    border-radius: 4px;
}

.now-playing-info { flex: 1; }
#player-title { font-weight: bold; color: var(--neon-cyan); }
#player-author { font-size: 0.8rem; color: var(--text-sub); }

/* ビジュアライザー */
#visualizer {
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    margin: 0 15px;
    box-shadow: inset 0 0 10px rgba(0, 240, 255, 0.05);
}

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

.player-controls button {
    background: transparent;
    border: 1px solid var(--neon-magenta);
    color: var(--neon-magenta);
    padding: 10px 20px;
    cursor: pointer;
    border-radius: 20px;
    font-weight: bold;
    transition: all 0.2s;
}
.player-controls button:hover:not(:disabled) {
    background: var(--neon-magenta);
    color: #fff;
    box-shadow: 0 0 10px var(--neon-magenta);
}
.player-controls button:disabled {
    border-color: var(--border-color);
    color: var(--text-sub);
    cursor: not-allowed;
}

/* 音量コントロールとカスタムスライダー */
.volume-control {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-left: 20px;
    color: var(--neon-cyan);
    font-size: 0.8rem;
    font-weight: bold;
}

#volume-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100px;
    background: transparent;
    cursor: pointer;
}

#volume-slider::-webkit-slider-runnable-track {
    width: 100%;
    height: 4px;
    background: var(--border-color);
    border-radius: 2px;
}

#volume-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    height: 14px;
    width: 14px;
    border-radius: 50%;
    background: var(--neon-magenta);
    margin-top: -5px;
    box-shadow: 0 0 8px var(--neon-magenta);
    transition: transform 0.1s;
}
#volume-slider::-webkit-slider-thumb:hover { transform: scale(1.2); }

/* =========================================
   Mobile Responsive (スマホ用調整)
========================================= */
@media (max-width: 768px) {
    .menu-btn { display: block; }

    /* サイドバーをオフキャンバス化 */
    .sidebar {
        position: absolute;
        top: 0;
        left: 0;
        height: 100%;
        transform: translateX(-100%);
        box-shadow: 5px 0 15px rgba(0, 0, 0, 0.8);
    }
    .sidebar.open { transform: translateX(0); }

    /* プレイヤーバーの折り返しレイアウト */
    .player-bar {
        height: auto;
        padding: 10px 15px;
        flex-wrap: wrap;
    }

    .player-cover { width: 50px; height: 50px; }
    .now-playing-info { width: calc(100% - 65px); margin-bottom: 10px; }

    /* スマホではビジュアライザーを隠してスペース確保 */
    #visualizer { display: none; }

    .player-controls {
        width: 100%;
        justify-content: center;
        gap: 15px;
    }

    .volume-control {
        width: 100%;
        justify-content: center;
        margin-top: 15px;
        margin-left: 0;
    }
    #volume-slider { width: 150px; }
}