/* STYLESHEET FOR SOUNDIFY - A MODERN MUSIC PLAYER */
        :root {
            --bg-deep: #0f172a;
            --bg-surface: #1e293b;
            --accent-soft: #818cf8;
            --accent-glow: rgba(129, 140, 248, 0.3);
            --text-main: #f8fafc;
            --text-muted: #94a3b8;
            --glass: rgba(30, 41, 59, 0.95);
        }

        body {
            background-color: var(--bg-deep);
            color: var(--text-main);
            font-family: 'Quicksand', sans-serif;
            overflow: hidden;
            height: 100vh;
        }

        /* STRICT LAYOUT DEFINITION */
        .app-container {
            display: grid;
            height: 100vh;
            /* Phone Default */
            grid-template-areas: 
                "main"
                "player";
            grid-template-columns: 1fr;
            grid-template-rows: 1fr auto;
        }

        @media (min-width: 768px) {
            /* Laptop Layout */
            .app-container {
                grid-template-areas: 
                    "sidebar main"
                    "player player";
                grid-template-columns: 260px 1fr;
                grid-template-rows: 1fr 110px;
            }
        }

        .sidebar {
            grid-area: sidebar;
            display: none; /* Hidden on phone */
            background-color: rgba(15, 23, 42, 0.98);
            backdrop-filter: blur(20px);
            padding: 32px 20px;
            flex-direction: column;
            gap: 30px;
            border-right: 1px solid rgba(255, 255, 255, 0.05);
            z-index: 60;
        }

        @media (min-width: 768px) {
            .sidebar {
                display: flex; /* Visible on laptop */
            }
        }

        .main-view {
            grid-area: main;
            background: radial-gradient(circle at top left, #1e1b4b, #0f172a 80%);
            overflow-y: auto;
            position: relative;
            padding: 1rem;
        }

        @media (min-width: 768px) {
            .main-view {
                padding: 3rem;
            }
        }

        .player-bar {
            grid-area: player;
            background: var(--glass);
            backdrop-filter: blur(40px);
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            display: flex;
            flex-direction: column;
            padding: 10px 16px;
            z-index: 100;
            position: relative;
            box-sizing: border-box;

        }

        @media (min-width: 768px) {
            .player-bar {
                flex-direction: row;
                padding: 12px 24px;
                align-items: center;
                justify-content: space-between;
            }
        }

        /* SONG ROWS - LAPTOP vs PHONE */
        .song-row {
            display: grid;
            /* Phone layout: Art+Title, Duration */
            grid-template-columns: 1fr 60px;
            gap: 12px;
            padding: 10px;
            border-radius: 12px;
            align-items: center;
            cursor: pointer;
            color: var(--text-muted);
            margin-bottom: 4px;
            transition: all 0.3s ease;
        }

        @media (min-width: 768px) {
            .song-row {
                /* Laptop layout: Index, Art+Title, Album, Duration */
                grid-template-columns: 50px 4fr 3fr 1fr;
                padding: 14px 20px;
                border-radius: 18px;
            }
        }

        .song-row:hover {
            background-color: rgba(255, 255, 255, 0.06);
            color: var(--text-main);
        }

        .song-row.active {
            background-color: rgba(129, 140, 248, 0.2);
            color: var(--accent-soft);
        }

        /* PROGRESS BAR */
        .progress-bar-container {
            width: 100%;
            height: 4px;
            background-color: rgba(255, 255, 255, 0.1);
            border-radius: 10px;
            position: relative;
            cursor: pointer;
        }

        .progress-bar-fill {
            height: 100%;
            background: linear-gradient(90deg, #818cf8, #c084fc);
            border-radius: 10px;
            width: 0%;
            transition: width 0.1s linear;
        }

        /* BUTTONS */
        .play-btn-circle {
            background: linear-gradient(135deg, #818cf8, #6366f1);
            color: white;
            width: 48px;
            height: 48px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 8px 20px rgba(99, 102, 241, 0.3);
            transition: all 0.3s;
        }

        .control-btn {
            color: var(--text-muted);
            transition: color 0.2s;
        }

        .control-btn:hover { color: white; }
        .control-btn.active { color: var(--accent-soft); }

        .glass-card {
            background: rgba(255, 255, 255, 0.03);
            backdrop-filter: blur(15px);
            border: 1px solid rgba(255, 255, 255, 0.08);
        }

        /* SCROLLBAR */
        ::-webkit-scrollbar { width: 6px; }
        ::-webkit-scrollbar-track { background: transparent; }
        ::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 10px; }