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

:root {
    --spotify-green: #1DB954;
    --spotify-black: #191414;
    --spotify-dark: #121212;
    --spotify-gray: #535353;
    --spotify-light-gray: #b3b3b3;
    --spotify-white: #ffffff;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--spotify-dark) 0%, var(--spotify-black) 100%);
    color: var(--spotify-white);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding: 30px 20px;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    color: var(--spotify-green);
}

header p {
    color: var(--spotify-light-gray);
    font-size: 1.1rem;
}

.auth-section {
    text-align: center;
    padding: 60px 20px;
}

.btn {
    padding: 15px 40px;
    font-size: 1rem;
    font-weight: bold;
    border: none;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn-primary {
    background-color: var(--spotify-green);
    color: var(--spotify-white);
}

.btn-primary:hover {
    background-color: #1ed760;
    transform: scale(1.05);
}

.btn-success {
    background-color: var(--spotify-green);
    color: var(--spotify-white);
    width: 100%;
    margin-top: 20px;
}

.btn-success:hover {
    background-color: #1ed760;
}

.main-content {
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 20px;
    padding: 40px;
    backdrop-filter: blur(10px);
}

.user-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding: 15px 20px;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 10px;
}

#userName {
    color: var(--spotify-green);
    font-weight: 600;
    font-size: 1rem;
}

.btn-logout {
    background-color: transparent;
    color: var(--spotify-white);
    border: 2px solid rgba(255, 255, 255, 0.3);
    padding: 8px 20px;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.btn-logout:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: var(--spotify-green);
    color: var(--spotify-green);
    transform: scale(1);
}

.user-info img {
    border-radius: 50%;
    width: 60px;
    height: 60px;
    margin-bottom: 10px;
}

.generator-section h2 {
    color: var(--spotify-green);
    margin-bottom: 25px;
    font-size: 1.8rem;
}

.theme-selector {
    margin-bottom: 25px;
}

.theme-selector label {
    display: block;
    margin-bottom: 10px;
    color: var(--spotify-light-gray);
    font-weight: 500;
}

.theme-selector input,
.theme-selector textarea {
    width: 100%;
    padding: 15px;
    font-size: 1rem;
    border: 2px solid var(--spotify-gray);
    border-radius: 10px;
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--spotify-white);
    transition: border-color 0.3s ease;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    resize: vertical;
}

.theme-selector input:focus,
.theme-selector textarea:focus {
    outline: none;
    border-color: var(--spotify-green);
}

.theme-selector .hint {
    margin-top: 8px;
    font-size: 0.85rem;
    color: var(--spotify-light-gray);
    font-style: italic;
}

.analysis-card {
    background: rgba(29, 185, 84, 0.05);
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid var(--spotify-green);
    margin: 20px 0;
}

.analysis-card p {
    margin: 10px 0;
    color: var(--spotify-white);
}

.analysis-card strong {
    color: var(--spotify-green);
}

.options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.option-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--spotify-light-gray);
    font-weight: 500;
}

.option-group input,
.option-group select {
    width: 100%;
    padding: 12px;
    font-size: 1rem;
    border: 2px solid var(--spotify-gray);
    border-radius: 10px;
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--spotify-white);
}

.option-group input:focus,
.option-group select:focus {
    outline: none;
    border-color: var(--spotify-green);
}

.option-group select option {
    background-color: var(--spotify-black);
}

.loading {
    text-align: center;
    padding: 40px;
}

.spinner {
    border: 4px solid rgba(255, 255, 255, 0.1);
    border-top: 4px solid var(--spotify-green);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

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

.results {
    margin-top: 30px;
}

.results h2 {
    color: var(--spotify-green);
    margin-bottom: 20px;
    font-size: 1.8rem;
}

.playlist-info {
    background-color: rgba(255, 255, 255, 0.05);
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 20px;
}

.track-list {
    max-height: 500px;
    overflow-y: auto;
    margin-bottom: 20px;
}

.track-item {
    display: flex;
    align-items: center;
    padding: 15px;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    margin-bottom: 10px;
    transition: background-color 0.3s ease;
}

.track-item:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.track-item img {
    width: 60px;
    height: 60px;
    border-radius: 5px;
    margin-right: 15px;
}

.track-info {
    flex: 1;
}

.track-name {
    font-weight: bold;
    color: var(--spotify-white);
    margin-bottom: 5px;
}

.track-artist {
    color: var(--spotify-light-gray);
    font-size: 0.9rem;
}

.track-duration {
    color: var(--spotify-light-gray);
    font-size: 0.9rem;
}

footer {
    text-align: center;
    margin-top: 40px;
    color: var(--spotify-light-gray);
    padding: 20px;
}

/* Scrollbar styling */
.track-list::-webkit-scrollbar {
    width: 10px;
}

.track-list::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
}

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

.track-list::-webkit-scrollbar-thumb:hover {
    background: #1ed760;
}

/* Responsive design */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .main-content {
        padding: 20px;
    }

    .options {
        grid-template-columns: 1fr;
    }

    .track-item {
        flex-direction: column;
        text-align: center;
    }

    .track-item img {
        margin-right: 0;
        margin-bottom: 10px;
    }
}