:root {
    --bg-color: #1a1a1a;
    --surface-color: #242424;
    --border-color: #333;
    --text-color: #e0e0e0;
    --text-inactive: #6b6b6b;
    --accent-color: #FFFFFF;
    --dynamic-accent-color: var(--accent-color);
}
body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
}
.flat-card {
    border-radius: 20px;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
}

.glass-panel {
    background: rgba(30, 30, 30, 0.6);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
}

.flat-button {
    border-radius: 50%;
    background: #333;
    color: var(--text-color);
    transition: background-color 0.2s ease-in-out, color 0.2s ease-in-out;
}
.flat-button:hover {
    background: #444;
}
.flat-button:active, .flat-button.active {
    background: #555;
    color: var(--accent-color);
}

#page-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    filter: blur(40px) brightness(0.4);
    transform: scale(1.1);
    z-index: -1;
    opacity: 0;
    transition: opacity 0.5s ease-in-out;
}

#lyrics-viewport {
    flex-grow: 1;
    overflow: hidden;
    position: relative;
    text-align: center;
}
#lyrics-content {
    position: absolute;
    width: 100%;
    top: 0;
    left: 0;
    transition: transform 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.lyric-line {
    font-size: 1.5rem;
    line-height: 2.5rem;
    font-weight: 500;
    padding: 0.5rem 0;
    opacity: 0.5;
    transition: color 0.4s ease, opacity 0.4s ease, transform 0.4s ease;
    transform: scale(0.9);
    text-shadow: 0 0 5px rgba(0,0,0,0.5);
}

.lyric-line.active-line {
    opacity: 1;
    transform: scale(1);
}

.lyric-word {
    display: inline-block;
    transition: color 0.3s ease, font-weight 0.3s ease, transform 1.2s ease, text-shadow 1.2s ease;
    color: var(--text-inactive);
}

.lyric-line.active-line .lyric-word.played {
    color: var(--text-color);
}

.lyric-line.active-line .lyric-word.active-word {
    color: var(--dynamic-accent-color);
    font-weight: 800;
    transform: scale(1.05);
}

.lyric-line.active-line .lyric-word.active-word.long-hold {
    transform: scale(1.15);
    text-shadow: 0 0 15px var(--dynamic-accent-color);
}

.chord {
    font-mono: text-sm;
    padding: 4px 12px;
    border-radius: 8px;
    transition: all 0.3s ease;
    background-color: #333;
    color: #aaa;
}
.chord.active {
    background-color: var(--dynamic-accent-color);
    color: black;
    font-weight: bold;
}
#chords-container {
     scrollbar-width: none; /* Firefox */
}
#chords-container::-webkit-scrollbar { 
    display: none;  /* Safari and Chrome */
}
#progress-bar {
    background-color: var(--dynamic-accent-color);
}