* {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: Arial, Helvetica, sans-serif;
    }

    body {
      background: linear-gradient(180deg, #121212 0%, #181818 55%, #0f0f0f 100%);
      color: #ffffff;
      min-height: 100vh;
    }

    /* Class for navigation bar and components: */
    .navbar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 1.2rem 2rem;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      position: sticky;
      top: 0;
      backdrop-filter: blur(8px);
      background: rgba(18, 18, 18, 0.8);
    }

    .nav-links a {
      text-decoration: none;
      color: #d1d1d1;
      transition: 0.2s;
    }

    .nav-links a:hover {
      color: #1ed760;
    }

    .nav-links a.active {
      color: #1ed760;
      font-weight: bold;
    }

    /* Mini Spotify + music note */
    .logo {
      font-size: 1.3rem;
      font-weight: bold;
      color: #1ed760;
    }

    /* Elements on the navigation bar */
    .nav-links {
      display: flex;
      gap: 1.2rem;
      list-style: none;
      color: #d1d1d1;
      font-size: 0.95rem;
    }

    /* Class for hero and compoenents: */
    .hero {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 2rem;
      align-items: center;
      max-width: 1200px;
      margin: 0 auto;
      padding: 5rem 2rem 4rem;
    }

    /* Hero header */
    .hero-text h1 {
      font-size: 3.8rem;
      line-height: 1.05;
      margin-bottom: 1rem;
    }

    /* Hero text */
    .hero-text p {
      color: #c8c8c8;
      font-size: 1.1rem;
      line-height: 1.7;
      max-width: 600px;
      margin-bottom: 1.8rem;
    }

    /* Class for buttons and compoenets: */
    .buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }

    .btn {
      padding: 0.95rem 1.4rem;
      border-radius: 999px;
      border: none;
      font-size: 1rem;
      cursor: pointer;
      transition: transform 0.2s ease, opacity 0.2s ease;
    }

    /* Hover effect - lift the button slughty */
    .btn:hover {
      transform: translateY(-2px);
      opacity: 0.95;
    }

    /* Primary button style - spotify green */
    .btn-primary {
      background: #1ed760;
      color: #111111;
      font-weight: bold;
    }

    /* Secondary button style - blakc and white */
    .btn-secondary {
      background: transparent;
      color: #ffffff;
      border: 1px solid rgba(255, 255, 255, 0.25);
    }

    /* Nested card components: */
    .hero-card {
      background: linear-gradient(180deg, rgba(30, 215, 96, 0.18), rgba(255, 255, 255, 0.04));
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: 28px;
      padding: 1.5rem;
      box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
    }

    .card-top {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 1.5rem;
      color: #d9d9d9;
      font-size: 0.95rem;
    }

    .playlist-box {
      background: rgba(255, 255, 255, 0.05);
      border-radius: 20px;
      padding: 1.2rem;
    }

    .playlist-box h3 {
      margin-bottom: 1rem;
      font-size: 1.3rem;
    }

    /* Song class and components: */
    .song {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0.9rem 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }

    .song:last-child {
      border-bottom: none;
    }

    /* Tile of a song */
    .song-info p:first-child {
      font-weight: bold;
      margin-bottom: 0.2rem;
    }

    /* Artist */
    .song-info p:last-child {
      color: #b8b8b8;
      font-size: 0.92rem;
    }

    /* Tag to indicate genre of a song */
    .tag {
      color: #1ed760;
      font-size: 0.9rem;
      font-weight: bold;
    }


    /* Features */
    .features {
      max-width: 1200px;
      margin: 0 auto;
      padding: 3rem 2rem 5rem;
    }

    /* FEatures section heading */
    .section-title {
      font-size: 2rem;
      margin-bottom: 1.5rem;
    }

    /* Create 3 column grid */
    .feature-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.2rem;
    }

    /* Card layout */
    .feature-card {
      background: rgba(255, 255, 255, 0.04);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: 22px;
      padding: 1.5rem;
    }

    /* Card heading */
    .feature-card h3 {
      margin-bottom: 0.8rem;
      font-size: 1.15rem;
    }

    /* Card text */
    .feature-card p {
      color: #c7c7c7;
      line-height: 1.6;
    }

    /* Footer */
    .footer {
      text-align: center;
      padding: 2rem;
      color: #8d8d8d;
      border-top: 1px solid rgba(255, 255, 255, 0.08);
    }

    /* Style for application */
    .app-container {
      max-width: 900px;
      margin: 0 auto;
      padding: 3rem 2rem;
    }

    .app-title {
      font-size: 2.5rem;
      margin-bottom: 2rem;
    }

    .search-bar {
      width: 100%;
      padding: 1rem;
      border-radius: 12px;
      border: none;
      margin-bottom: 2rem;
      font-size: 1rem;
    }

    .song-list {
      display: flex;
      flex-direction: column;
      gap: 1rem;
    }

    .song-card {
      background: rgba(255, 255, 255, 0.05);
      padding: 1rem 1.5rem;
      border-radius: 16px;
      transition: 0.2s;
    }

    .song-card:hover {
      background: rgba(255, 255, 255, 0.08);
    }

    .song-title {
      font-weight: bold;
    }

    .song-artist {
      color: #b3b3b3;
    }

    .song-card {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .back-btn {
      background: rgba(255, 255, 255, 0.1);
      padding: 0.4rem 0.8rem;
      border-radius: 8px;
      text-decoration: none;
      color: white;
    }

    .back-btn:hover {
      text-decoration: underline;
    }

    .add-btn {
      background: #1ed760;
      border: none;
      border-radius: 50%;
      width: 35px;
      height: 35px;
      font-size: 18px;
      cursor: pointer;
    }

    .add-btn:hover {
      opacity: 0.8;
    }

    .app-layout {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 1.5rem;
      align-items: start;
    }

    .panel-heading {
      font-size: 1.4rem;
      margin-bottom: 1rem;
    }

    .library-panel,
    .playlist-panel {
      background: rgba(255, 255, 255, 0.03);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: 24px;
      padding: 1.5rem;
    }

    .playlist-panel {
      height: fit-content;
    }

    .playlist-card {
      background: rgba(255, 255, 255, 0.05);
      border-radius: 16px;
      padding: 1rem 1.1rem;
      margin-bottom: 1rem;
      transition: 0.2s;
    }

    .playlist-card:hover {
      background: rgba(255, 255, 255, 0.08);
    }

    .playlist-name {
      font-weight: bold;
      margin-bottom: 0.35rem;
    }

    .playlist-count {
      color: #b3b3b3;
      font-size: 0.95rem;
    }

    @media (max-width: 900px) {
      .app-layout {
        grid-template-columns: 1fr;
      }
    }

    .playlist-input {
      display: flex;
      gap: 0.5rem;
      margin-bottom: 1.2rem;
    }

    .playlist-name-input {
      flex: 1;
      padding: 0.7rem;
      border-radius: 10px;
      border: none;
    }

    .create-playlist-btn {
      padding: 0.7rem 1rem;
      border-radius: 10px;
      border: none;
      background: #1ed760;
      color: black;
      font-weight: bold;
      cursor: pointer;
    }

    .create-playlist-btn:hover {
      opacity: 0.9;
    }

    .selected-playlist {
      border: 2px solid #1ed760;
    }


    .playlists-page {
      max-width: 1100px;
      margin: 0 auto;
      padding: 3rem 2rem 5rem;
    }

    .page-description {
      color: #b3b3b3;
      font-size: 1.1rem;
      margin-bottom: 2rem;
      max-width: 650px;
      line-height: 1.6;
    }

    .playlist-page-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.5rem;
    }

    .playlist-detail-card {
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: 24px;
      padding: 1.5rem;
      min-height: 260px;
    }

    .playlist-detail-card h2 {
      margin-bottom: 0.5rem;
    }

    .playlist-song {
      display: flex;
      justify-content: space-between;
      gap: 1rem;
      padding: 0.9rem 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }

    .playlist-song small,
    .empty-note {
      color: #b3b3b3;
    }

    @media (max-width: 900px) {
      .playlist-page-grid {
        grid-template-columns: 1fr;
      }
    }

    .playlist-link {
      text-decoration: none;
      color: inherit;
    }

    .song-list {
      display: flex;
      flex-direction: column;
      gap: 1rem;

      max-height: 500px;
      overflow-y: auto;
      padding-right: 0.5rem;
    }

    .song-list::-webkit-scrollbar {
      width: 8px;
    }

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

    .song-list::-webkit-scrollbar-thumb {
      background: #1ed760;
      border-radius: 10px;
    }