:root {
    --bg-dark: #0a0e14;
    --neon-blue: #00f3ff;
    --neon-purple: #bc13fe;
    --text-glow: 0 0 10px rgba(0, 243, 255, 0.5);
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-border: rgba(255, 255, 255, 0.1);
}

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

body {
    background-color: var(--bg-dark);
    background-image: radial-gradient(circle at 50% 50%, #1a2a3a 0%, #0a0e14 100%);
    color: white;
    font-family: 'Noto Sans JP', sans-serif;
    display: block;
    min-height: 100vh;
    padding: 10px;
    overflow-y: auto;
    /* 明示的に縦スクロールを許可 */
}

.glass-container {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    width: 100%;
    max-width: 500px;
    padding: 25px 15px;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.5);
    position: relative;
    z-index: 1;
    margin: 10px auto;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 1.8rem;
    letter-spacing: 2px;
    color: var(--neon-blue);
    text-shadow: var(--text-glow);
    margin-bottom: 5px;
}

header p {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.5);
    text-transform: uppercase;
    letter-spacing: 3px;
}

/* Visualizer */
#visualizer-container {
    display: flex;
    align-items: flex-end;
    justify-content: center;
    gap: 4px;
    height: 60px;
    margin-bottom: 30px;
}

.visualizer-bar {
    width: 4px;
    height: 10px;
    background: linear-gradient(to top, var(--neon-blue), var(--neon-purple));
    border-radius: 2px;
    transition: height 0.1s ease;
}

/* Playing Info */
.now-playing {
    margin-bottom: 30px;
}

.track-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
    margin-bottom: 10px;
}

#currentTrackTitle {
    font-weight: 700;
}

.progress-bar-container {
    width: 100%;
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 3px;
    overflow: hidden;
    cursor: pointer;
}

#progressBar {
    width: 0%;
    height: 100%;
    background: var(--neon-blue);
    box-shadow: 0 0 10px var(--neon-blue);
    transition: width 0.1s linear;
}

.controls {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    margin-bottom: 40px;
}

.volume-container {
    display: flex;
    align-items: center;
    gap: 15px;
    width: 100%;
    padding: 0 20px;
}

.volume-icon {
    font-family: 'Orbitron', sans-serif;
    font-size: 0.7rem;
    color: var(--neon-blue);
}

#volumeSlider {
    flex-grow: 1;
    -webkit-appearance: none;
    background: rgba(255, 255, 255, 0.1);
    height: 4px;
    border-radius: 2px;
    outline: none;
}

#volumeSlider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 15px;
    height: 15px;
    background: var(--neon-blue);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 10px var(--neon-blue);
}

.main-btn {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    border: none;
    background: var(--glass-bg);
    border: 1px solid var(--neon-blue);
    color: var(--neon-blue);
    font-size: 2rem;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 0 15px rgba(0, 243, 255, 0.2);
}

.main-btn:hover:not(:disabled) {
    transform: scale(1.1);
    box-shadow: 0 0 25px rgba(0, 243, 255, 0.4);
    background: rgba(0, 243, 255, 0.1);
}

.main-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

/* Filter Section */
.filter-section {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.search-box {
    flex-grow: 2;
}

#trackSearch {
    width: 100%;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    padding: 10px 15px;
    color: white;
    outline: none;
    transition: all 0.3s ease;
}

#trackSearch:focus {
    border-color: var(--neon-blue);
    box-shadow: 0 0 10px rgba(0, 243, 255, 0.2);
    background: rgba(255, 255, 255, 0.1);
}

.pack-selector {
    flex-grow: 1;
}

#packSelect {
    width: 100%;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    padding: 10px;
    color: white;
    outline: none;
    cursor: pointer;
}

#packSelect option {
    background: var(--bg-dark);
}

/* Track List */
.track-list {
    max-height: 300px;
    overflow-y: auto;
    padding-right: 10px;
}

.track-list::-webkit-scrollbar {
    width: 4px;
}

.track-list::-webkit-scrollbar-thumb {
    background: var(--glass-border);
    border-radius: 10px;
}

.track-item {
    display: flex;
    align-items: center;
    padding: 15px;
    border-radius: 15px;
    background: rgba(255, 255, 255, 0.02);
    margin-bottom: 10px;
    cursor: pointer;
    transition: all 0.2s ease;
    border: 1px solid transparent;
}

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

.track-item.active {
    background: rgba(0, 243, 255, 0.05);
    border-color: var(--neon-blue);
}

.track-number {
    font-family: 'Orbitron', sans-serif;
    font-size: 0.8rem;
    color: var(--neon-blue);
    margin-right: 15px;
    width: 25px;
}

.track-name {
    flex-grow: 1;
    font-size: 0.95rem;
}

.track-length {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.3);
}

footer {
    text-align: center;
    margin-top: 30px;
    font-size: 0.7rem;
    color: rgba(255, 255, 255, 0.3);
    letter-spacing: 1px;
}