body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 20px;
    background-color: #121212;
    color: #fff;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

h1 {
    color: #1DB954; /* Spotify Green */
}

main {
    max-width: 900px;
    margin: 0 auto;
    display: grid;
    gap: 40px;
}

section {
    background: #282828;
    padding: 20px;
    border-radius: 8px;
}

#file-upload-section {
    text-align: center;
}

#drop-zone {
    border: 2px dashed #444;
    border-radius: 8px;
    padding: 30px;
    transition: border-color 0.3s, background-color 0.3s;
}

#drop-zone.dragover {
    border-color: #1DB954;
    background-color: #333;
}

#drop-zone p {
    color: #b3b3b3;
    margin-top: 15px;
}

/* Custom file input button */
.custom-file-upload {
    background-color: #1DB954;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 1em;
    display: inline-block;
    transition: background-color 0.3s;
}

.custom-file-upload:hover {
    background-color: #1ed760;
}

#json-files-input {
    display: none;
}

#file-count {
    margin-left: 15px;
    font-size: 0.9em;
}

button {
    background-color: #1DB954;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 1em;
    transition: background-color 0.3s;
    margin-top: 20px;
}

button:hover {
    background-color: #1ed760;
}

.hidden {
    display: none;
}

#loader {
    border: 5px solid #444;
    border-top: 5px solid #1DB954;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

#error-message {
    color: #ff6b6b;
    margin-top: 15px;
}

#summary-section h2, #charts-section h2 {
    text-align: center;
    margin-bottom: 20px;
}

#stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    text-align: center;
}

.stat-item {
    background: #333;
    padding: 15px;
    border-radius: 6px;
}

.stat-item h3 {
    margin: 0 0 5px 0;
    font-size: 1.5em;
    color: #1DB954;
}

.stat-item p {
    margin: 0;
    font-size: 0.9em;
    color: #b3b3b3;
}

#charts-container {
    display: grid;
    gap: 40px;
}

canvas {
    width: 100% !important;
    aspect-ratio: 16 / 9;
}

footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 40px;
    padding-top: 20px;
}

.footer-placeholder, .version {
    flex: 1;
}

.bmc-container {
    flex: 1;
    text-align: center;
}