* {
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5eedc; /* Light beige background */
    color: #4a3c31; /* Deep brown text for contrast */
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
}

.container {
    max-width: 1000px;
    width: 100%;
    background: #fffcf5; /* Very soft off-white/cream */
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 8px 25px rgba(74, 60, 49, 0.1); /* Soft brown shadow */
}

h1 {
    text-align: center;
    margin-top: 0;
    color: #5c4a3d; /* Darkish brown */
}

p {
    text-align: center;
    color: #8a7360; /* Muted brown */
    margin-bottom: 20px;
}

.piano-wrapper {
    overflow-x: auto;
    padding: 10px 0 20px 0;
    margin-bottom: 20px;
    display: flex;
    justify-content: center;
}

/* Authentic Piano Layout CSS - Wood & Warmth */
.piano {
    position: relative;
    display: flex;
    background: #4a3c31; /* Dark wood chassis */
    border-radius: 5px;
    padding: 4px;
    width: max-content; 
    margin: 0 auto;
    box-shadow: inset 0 2px 5px rgba(0,0,0,0.4), 0 5px 15px rgba(74, 60, 49, 0.2);
}

.key {
    cursor: pointer;
    user-select: none;
    border-radius: 0 0 4px 4px;
    transition: background 0.1s;
}

.white-key {
    width: 40px;
    height: 160px;
    background: #fffdf9; /* Ivory/warm white keys */
    border: 1px solid #dcd3c6; /* Soft beige borders */
    margin: 0 1px;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding-bottom: 8px;
    font-size: 11px;
    font-weight: bold;
    color: #6e5c4f;
    z-index: 1;
}

.white-key:hover { background: #f0e9df; }
.white-key.active { background: #e2d5c4; }

.black-key {
    width: 24px;
    height: 100px;
    background: #2b231d; /* Espresso */
    position: absolute;
    top: 4px; 
    z-index: 2;
    border-radius: 0 0 3px 3px;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding-bottom: 8px;
    font-size: 9px;
    color: #b5a496;
    box-shadow: inset 0 -2px 3px rgba(255,255,255,0.05);
}

.black-key:hover { background: #45372e; }
.black-key.active { background: #5c4a3d; }

.controls {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-bottom: 20px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.2s;
    color: white;
}

.btn-primary { background: #c29b7a; } 
.btn-primary:hover { background: #a88365; }
.btn-danger { background: #c27a7a; } 
.btn-danger:hover { background: #a86565; }
.btn-success { background: #9bb582; } 
.btn-success:hover { background: #82996a; }

/* Rich Text Editor */
.output-area {
    width: 100%;
}

#tab-editor {
    width: 100%;
    min-height: 250px;
    padding: 15px;
    font-size: 18px;
    border: 2px solid #e0d5c1; 
    border-radius: 8px;
    background: #fffcf5;
    font-family: monospace;
    white-space: pre-wrap; 
    word-wrap: break-word;
    outline: none;
    line-height: 1.8;
    user-select: text;
    color: #4a3c31;
    position: relative;
}

#tab-editor:focus {
    border-color: #c29b7a; 
    box-shadow: 0 0 0 3px rgba(194, 155, 122, 0.2);
}

/* Custom placeholder class */
#tab-editor.is-empty:before {
    content: attr(placeholder);
    color: #b5a496;
    pointer-events: none;
    position: absolute;
    top: 15px;
    left: 15px;
    display: block;
}

/* Hoverable Note Pill */
.tab-note {
    font-weight: bold;
    color: #8c6a4f; 
    cursor: pointer;
    display: inline; 
    transition: background-color 0.2s;
    border-bottom: 1px dashed transparent;
}

.tab-note:hover {
    background-color: #f0e9df; 
    border-bottom: 1px dashed #b5a496;
    border-radius: 2px;
}

/* Popup Menu */
.popup {
    position: absolute;
    background: #fffcf5;
    border: 1px solid #e0d5c1;
    box-shadow: 0 8px 20px rgba(74, 60, 49, 0.15);
    border-radius: 8px;
    padding: 8px;
    z-index: 100;
    width: max-content;
}

.popup-options {
    display: flex;
    gap: 6px;
}

.popup-btn {
    padding: 6px 12px;
    border: 1px solid #e0d5c1;
    background: #f5eedc;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    font-weight: bold;
    color: #5c4a3d;
}

.popup-btn:hover {
    background: #e2d5c4;
}

.hidden {
    display: none;
}