* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            user-select: none; /* avoid accidental drag on buttons */
        }


        /* main player card */
        .player-app {
            max-width: 1300px;
            width: 100%;
            background: rgba(18, 24, 32, 0.75);
            backdrop-filter: blur(2px);
            border-radius: 2rem;
            box-shadow: 0 25px 45px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(255, 255, 255, 0.05);
            overflow: hidden;
            transition: all 0.2s;
        }

        /* ----- TOP NAVIGATION BAR (with submenu) ----- */
        .top-nav {
            background: #0f1219e6;
            backdrop-filter: blur(12px);
            border-bottom: 1px solid rgba(255, 255, 255, 0.08);
            padding: .0rem .0rem .0rem;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            gap: 0rem;
        }

        .nav-brand {
            display: flex;
            align-items: center;
            gap: 0px;
        }
        .nav-brand h2 {
            font-size: 0rem;
            font-weight: 600;
            background: linear-gradient(135deg, #E0E7FF, #A5B4FC);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            letter-spacing: -0.3px;
        }
        .brand-icon {
            font-size: 0rem;
        }

        /* main menu items */
        .nav-menu {
            display: flex;
            gap: 0.8rem;
            flex-wrap: wrap;
        }
        .nav-item {
            position: relative;
        }
        .nav-btn {
            background: transparent;
            border: none;
            color: #cdd9ff;
            font-weight: 500;
            font-size: 0.95rem;
            padding: .0rem .0rem .0rem;
            border-radius: 40px;
            cursor: pointer;
            transition: 0.2s;
            display: flex;
            align-items: center;
            gap: 6px;
            font-family: inherit;
        }
        .nav-btn:hover, .nav-btn.active {
            background: rgba(255, 255, 255, 0.1);
            color: white;
        }

        /* submenu (dropdown) */
        .submenu {
            position: absolute;
            top: 45px;
            left: 0;
            background: #1a1f2be0;
            backdrop-filter: blur(16px);
            border-radius: 1rem;
            padding: 0.5rem 0;
            min-width: 170px;
            flex-direction: column;
            z-index: 200;
            border: 1px solid rgba(255,255,255,0.1);
            box-shadow: 0 10px 25px -5px rgba(0,0,0,0.5);
            display: none;
        }
        .submenu.show {
            display: flex;
        }
        .submenu button {
            background: transparent;
            border: none;
            text-align: left;
            padding: 0.65rem 1.2rem;
            color: #e2e8ff;
            font-size: 0.85rem;
            cursor: pointer;
            transition: 0.1s;
            width: 100%;
            font-family: inherit;
        }
        .submenu button:hover {
            background: #2d3445;
            color: white;
        }

        /* ---- TOP PLAYER CORE (big prominent area) ---- */
        .top-player-core {
            background: #181a1b;
            border-radius: 1.8rem;
            padding: .0rem 1.0rem .0rem;
            backdrop-filter: blur(4px);
              display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            gap: 1.2rem;
        }

        .track-info {
            flex: 2;
            min-width: 180px;
        }
        .track-info .now-playing-label {
            font-size: 0.7rem;
            text-transform: uppercase;
            letter-spacing: 1px;
            color: #8e9eff;
        }
        .track-info h3 {
            font-size: 1.2rem;
            font-weight: 600;
            color: white;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }
        .track-info p {
            font-size: 0.8rem;
            color: #a3b3d8;
        }

        .player-controls {
            flex: 2;
            display: flex;
            flex-direction: column;
            gap: 0.7rem;
            min-width: 220px;
        }
        .control-buttons {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 1rem;
        }
        .ctrl-btn {
            background: #1e2538;
            border: none;
            width: 42px;
            height: 42px;
            border-radius: 60px;
            font-size: 1.5rem;
            color: white;
            cursor: pointer;
            transition: 0.1s;
            display: inline-flex;
            align-items: center;
            justify-content: center;
        }
        .ctrl-btn:hover {
            background: #2f3a55;
            transform: scale(1.02);
        }
        .ctrl-btn.play-pause {
            background: #4f46e5;
            width: 42px;
            height: 42px;
            font-size: 1.3rem;
        }
        .progress-area {
            display: flex;
            align-items:center;
            gap: 10px;width:98%;
            font-size: 0.7rem;
            color: #b9c3e6;
        }
        input[type="range"] {
            height: 4px;width:55%;
            -webkit-appearance: none;
            background: #2d3448;
            border-radius: 5px;
        }
        input[type="range"]:focus {
            outline: none;
        }
        input[type="range"]::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            background: #a5b4fc;
            cursor: pointer;
        }
        .volume-wrap {
            display: flex;
            align-items: center;
            gap: 8px;
            background: #11161f;
            border-radius: 40px;
			
        }
        .volume-wrap span {
            font-size: 0.9rem;
        }

        /* playlist navigation + submenu-bar combined region */
        .playlist-nav-section {
            margin: .5rem .2rem 0 .2rem;
        }
        .playlist-tabs {
            display: flex;
            gap: 0.5rem;
            flex-wrap: wrap;
            border-bottom: 1px solid rgba(255,255,255,0.1);
            padding-bottom: 0.0rem;
        }
        .playlist-tab {
            background: transparent;
            border: none;
            padding:.2rem 0.6rem .5rem;
            border-radius: 30px;
            color: #b9c3e6;
            font-weight: 500;
            cursor: pointer;
            transition: 0.15s;
        }
        .playlist-tab.active {
            background: #2d3a5e;
            color: white;
        }

        /* submenu-bar (horizontal secondary actions under playlist nav) */
        .submenu-bar {
            display: flex;
            align-items: center;
            gap: 0.8rem;
            margin-top: 0.7rem;
            margin-bottom: 0.5rem;
            flex-wrap: wrap;
        }
        .submenu-btn {
            background: rgba(30, 38, 56, 0.8);
            border: none;
            padding: 0.3rem 1rem;
            border-radius: 40px;
            font-size: 0.75rem;
            color: #cad2ff;
            cursor: pointer;
            transition: 0.1s;
        }
        .submenu-btn:hover {
            background: #3c456b;
            color: white;
        }

        /* tracks list container */
        .tracks-container {
            margin: 0.5rem 1.5rem 1.8rem 1.5rem;
            background: #0b0f17a0;
            border-radius: 1.4rem;
            padding: 0.6rem;
            max-height: 320px;
            overflow-y: auto;
        }
        .track-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0.7rem 1rem;
            border-radius: 1rem;
            margin-bottom: 6px;
            background: #11161f70;
            transition: 0.1s;
            cursor: pointer;
        }
        .track-item.active-track {
            background: #2d3566;
            border-left: 4px solid #818cf8;
        }
        .track-item:hover {
            background: #1e253e;
        }
        .track-name {
            font-weight: 500;
            color: #f0f3ff;
        }
        .track-duration {
            font-size: 0.7rem;
            color: #8d9ad0;
        }
        .empty-playlist {
            text-align: center;
            padding: 2rem;
            color: #7a85b0;
        }

        /* responsive */
        @media (max-width: 750px) {
            .top-player-core {
                flex-direction: column;
                align-items: stretch;
            }
            .player-controls {
                width: 100%;
            }
            .top-nav {
                flex-direction: column;
                align-items: stretch;
            }
        }
        ::-webkit-scrollbar {
            width: 5px;
        }