body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    margin: 0;
    padding: 0 0 100px 0;
    background: #050505;
    color: #f5f5f5;
    line-height: 1.6;
}

.main-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2rem;
    margin: 0;
    color: #1db954;
    font-weight: 700;
}

header p {
    color: #b3b3b3;
    font-size: 1rem;
    margin-top: 0.5rem;
}

.player-container-fixed {
    box-sizing: border-box;
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background: rgba(18, 18, 18, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    z-index: 1000;
    padding: 1rem 2rem;
}

.player-container {
    width: 100%;
}

.now-playing {
    display: flex;
    align-items: center;
    gap: 2rem;
    width: 100%;
}

.track-info {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-basis: 30%;
    flex-shrink: 0;
    min-width: 0;
}

.track-title {
    margin: 0;
    font-size: 1rem;
    font-weight: 600;
    color: #fff;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.track-instructor {
    margin: 0;
    color: #a7a7a7;
    font-size: 0.9rem;
}

.player-controls-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.player-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
}

.control-btn {
    background: transparent;
    border: none;
    color: #b3b3b3;
    font-size: 1.5rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

.control-btn:hover {
    color: #fff;
    transform: scale(1.1);
}

#play-btn {
    background: #1db954;
    color: #fff;
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 50%;
    font-size: 1.2rem;
}

.progress-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    width: 100%;
}

#progress-bar {
    flex-grow: 1;
    height: 5px;
    cursor: pointer;
    -webkit-appearance: none;
    appearance: none;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 2.5px;
}

#progress-bar::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    background: #fff;
    border-radius: 50%;
    cursor: pointer;
    margin-top: -4.5px;
    transition: all 0.2s ease;
}

#progress-bar:hover::-webkit-slider-thumb {
    background: #1db954;
    transform: scale(1.2);
}

.current-time, .duration {
    font-size: 0.85rem;
    color: #b3b3b3;
    min-width: 40px;
    text-align: center;
}

.playlist-container {
    background: transparent;
}

.playlist {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.playlist li {
    background: #1a1a1a;
    padding: 1rem 1.2rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

.playlist li:hover {
    background-color: #282828;
    transform: translateY(-5px);
    border-color: #1db954;
}

.playlist li span {
    color: #a7a7a7;
    font-size: 0.9rem;
}

.semester {
    margin-bottom: 2rem;
    grid-column: 1 / -1;
}

.semester h3 {
    color: #fff;
    margin: 0 0 1.5rem 0;
    font-size: 1.5rem;
    font-weight: 600;
    border-bottom: 2px solid #1db954;
    padding-bottom: 0.5rem;
    display: inline-block;
}

.subject {
    margin-bottom: 1.5rem;
    display: grid;
    gap: 0.75rem;
}

.subject h4 {
    color: #f5f5f5;
    margin: 0;
    font-weight: 500;
    font-size: 1.2rem;
}

/* Responsive styles */
@media (max-width: 768px) {
    body {
        padding-bottom: 120px;
    }

    .player-container-fixed {
        padding: 1rem;
    }

    .now-playing {
        flex-direction: column;
        gap: 1rem;
    }

    .track-info {
        justify-content: center;
        text-align: center;
    }

    .player-controls-container {
        width: 100%;
    }

    .progress-container {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .playlist {
        grid-template-columns: 1fr;
    }
}