:root {
    --bg-base: #060a13;
    --bg-surface: rgba(15, 20, 35, 0.85);
    --bg-card: rgba(20, 27, 45, 0.7);
    --border-glass: rgba(255, 255, 255, 0.06);
    --border-hover: rgba(255, 255, 255, 0.15);
    --text-primary: #eef2ff;
    --text-secondary: #7c8db5;
    --text-muted: #4a5578;
    --accent-primary: #818cf8;
    --accent-secondary: #22d3ee;
    --accent-gradient: linear-gradient(135deg, #818cf8, #22d3ee);
    --accent-glow: rgba(129, 140, 248, 0.25);
    --danger: #f87171;
    --success: #34d399;

    --radius-xl: 20px;
    --radius-lg: 14px;
    --radius-md: 10px;
    --radius-sm: 6px;

    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-base);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* === Ambient Background === */
.bg-orb {
    position: fixed;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.35;
    pointer-events: none;
    z-index: 0;
    animation: orbFloat 20s ease-in-out infinite alternate;
}
.orb-1 { width: 500px; height: 500px; background: #6366f1; top: -10%; left: -5%; }
.orb-2 { width: 400px; height: 400px; background: #06b6d4; bottom: -5%; right: -5%; animation-delay: -7s; }
.orb-3 { width: 300px; height: 300px; background: #a855f7; top: 40%; left: 50%; animation-delay: -14s; }

@keyframes orbFloat {
    0% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(30px, -20px) scale(1.1); }
    100% { transform: translate(-20px, 15px) scale(0.95); }
}

/* === App Container === */
.app-container {
    position: relative;
    z-index: 1;
    max-width: 1400px;
    margin: 0 auto;
    padding: 1.25rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    min-height: 100vh;
}

/* === Glass Panel === */
.glass-panel {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255,255,255,0.04);
}

/* === Header === */
.main-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
}

.logo { display: flex; align-items: center; gap: 0.75rem; }
.logo-icon-wrap {
    width: 42px; height: 42px;
    background: var(--accent-gradient);
    border-radius: var(--radius-md);
    display: flex; align-items: center; justify-content: center;
    box-shadow: 0 4px 20px var(--accent-glow);
}
.logo-icon { color: white; width: 22px; height: 22px; }
h1 { font-size: 1.4rem; font-weight: 700; letter-spacing: -0.02em; }
.logo-sub { font-size: 0.72rem; color: var(--text-muted); font-weight: 500; letter-spacing: 0.08em; text-transform: uppercase; }
h2 { font-size: 0.95rem; font-weight: 600; margin-bottom: 0; color: var(--text-primary); letter-spacing: -0.01em; }

.header-actions { display: flex; gap: 0.5rem; }

/* === Buttons === */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 0.4rem;
    padding: 0.5rem 1rem; border: none; border-radius: var(--radius-md);
    font-family: inherit; font-weight: 600; font-size: 0.82rem;
    cursor: pointer; transition: var(--transition); color: var(--text-primary);
    letter-spacing: 0.01em;
}
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
.btn.primary {
    background: var(--accent-gradient);
    box-shadow: 0 2px 12px var(--accent-glow);
}
.btn.primary:hover:not(:disabled) { transform: translateY(-1px); box-shadow: 0 4px 20px var(--accent-glow); }
.btn.secondary { background: rgba(255, 255, 255, 0.06); border: 1px solid var(--border-glass); }
.btn.secondary:hover:not(:disabled) { background: rgba(255, 255, 255, 0.12); border-color: var(--border-hover); }

.icon-btn {
    padding: 0.45rem; border-radius: var(--radius-sm); background: rgba(255,255,255,0.04);
    border: 1px solid var(--border-glass); cursor: pointer; transition: var(--transition);
    display: flex; align-items: center; justify-content: center; color: var(--text-secondary);
}
.icon-btn:hover { background: rgba(255,255,255,0.1); color: var(--text-primary); }
.icon-btn.danger:hover { background: rgba(248, 113, 113, 0.2); color: var(--danger); border-color: rgba(248,113,113,0.3); }

.roblox-btn {
    background: linear-gradient(135deg, #00b06f, #00d4aa) !important;
    box-shadow: 0 2px 12px rgba(0, 176, 111, 0.25);
}
.roblox-btn:hover { transform: translateY(-1px); box-shadow: 0 4px 18px rgba(0, 176, 111, 0.4); }

/* === Transport Bar === */
.transport-bar {
    display: flex; align-items: center; justify-content: space-between;
    padding: 0.6rem 1.25rem; gap: 1rem;
}
.transport-left, .transport-right { display: flex; align-items: center; gap: 0.5rem; flex: 1; }
.transport-right { justify-content: flex-end; }
.transport-center { display: flex; flex-direction: column; align-items: center; gap: 0.15rem; }

.transport-btn {
    width: 38px; height: 38px; border-radius: 50%; border: 1px solid var(--border-glass);
    background: rgba(255,255,255,0.04); color: var(--text-secondary);
    display: flex; align-items: center; justify-content: center;
    cursor: pointer; transition: var(--transition);
}
.transport-btn:hover:not(:disabled) { background: rgba(255,255,255,0.1); color: var(--text-primary); }
.transport-btn:disabled { opacity: 0.3; cursor: not-allowed; }
.transport-btn.play-btn { width: 48px; height: 48px; background: var(--accent-gradient); color: white; border: none; box-shadow: 0 2px 15px var(--accent-glow); }
.transport-btn.play-btn:hover:not(:disabled) { transform: scale(1.05); box-shadow: 0 4px 25px var(--accent-glow); }
#btn-loop.active { background: var(--accent-gradient); color: white; border-color: transparent; }

.time-display { display: flex; align-items: baseline; gap: 0.25rem; font-variant-numeric: tabular-nums; }
#time-current { font-size: 1.5rem; font-weight: 700; color: var(--text-primary); }
.time-separator { font-size: 1rem; color: var(--text-muted); }
#time-total { font-size: 1rem; font-weight: 500; color: var(--text-muted); }
.transport-status { font-size: 0.7rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.1em; font-weight: 600; }
.transport-label { font-size: 0.72rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.06em; }
.preset-name-display { font-size: 0.85rem; font-weight: 600; color: var(--accent-primary); }

/* === Main Content === */
.main-content {
    display: grid; grid-template-columns: 1fr 340px; gap: 1rem; flex: 1;
}
@media (max-width: 900px) {
    .main-content { grid-template-columns: 1fr; }
    .btn-label { display: none; }
}

/* === Tracks Section === */
.tracks-section { display: flex; flex-direction: column; gap: 0.75rem; }
.section-header {
    display: flex; justify-content: space-between; align-items: center;
    padding: 0.75rem 1rem;
}
.section-title { display: flex; align-items: center; gap: 0.5rem; }
.section-title i { width: 16px; height: 16px; color: var(--text-muted); }
.track-count {
    background: var(--accent-gradient); color: white; font-size: 0.65rem; font-weight: 700;
    padding: 0.15rem 0.5rem; border-radius: 99px; min-width: 20px; text-align: center;
}
.add-track-btn {
    background: rgba(255,255,255,0.04) !important; border: 1px dashed var(--border-hover) !important;
    color: var(--text-secondary) !important; font-size: 0.8rem !important; padding: 0.4rem 0.85rem !important;
    cursor: pointer;
}
.add-track-btn:hover { background: rgba(255,255,255,0.08) !important; color: var(--text-primary) !important; }

.track-list {
    flex: 1; display: flex; flex-direction: column; gap: 0.5rem;
    overflow-y: auto; max-height: 520px; padding-right: 0.25rem;
}
.track-list::-webkit-scrollbar { width: 4px; }
.track-list::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 10px; }

/* Empty State */
.empty-state {
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    padding: 4rem 1rem; color: var(--text-muted); border: 1px dashed rgba(255,255,255,0.08);
    border-radius: var(--radius-lg); text-align: center; background: rgba(0,0,0,0.15);
}
.empty-icon-wrap {
    width: 64px; height: 64px; border-radius: 50%; background: rgba(255,255,255,0.03);
    border: 1px solid var(--border-glass); display: flex; align-items: center; justify-content: center;
    margin-bottom: 1rem;
}
.empty-icon-wrap i { width: 28px; height: 28px; opacity: 0.3; }
.empty-state h3 { font-size: 1rem; font-weight: 600; color: var(--text-secondary); margin-bottom: 0.35rem; }
.empty-state p { font-size: 0.82rem; }

/* Track Item */
.track-item {
    background: var(--bg-card); border: 1px solid var(--border-glass);
    border-radius: var(--radius-md); overflow: hidden; transition: var(--transition);
    animation: slideUp 0.3s ease-out;
}
.track-item:hover { border-color: var(--border-hover); box-shadow: 0 2px 20px rgba(0,0,0,0.3); }
@keyframes slideUp { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

.track-info { flex: 1; overflow: hidden; }
.track-name { font-weight: 600; font-size: 0.85rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* === Sidebar === */
.sidebar { display: flex; flex-direction: column; gap: 1rem; }
.panel-header { display: flex; align-items: center; gap: 0.5rem; margin-bottom: 1rem; }
.panel-header i { width: 16px; height: 16px; color: var(--accent-primary); }

/* Presets */
.preset-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.5rem; }
.preset-btn {
    background: rgba(255,255,255,0.03); border: 1px solid var(--border-glass);
    padding: 0.6rem 0.5rem; border-radius: var(--radius-md);
    color: var(--text-secondary); font-family: inherit; font-weight: 600; font-size: 0.78rem;
    cursor: pointer; transition: var(--transition); text-align: left;
    display: flex; align-items: center; gap: 0.4rem;
}
.preset-btn i { width: 14px; height: 14px; opacity: 0.5; }
.preset-btn:hover { background: rgba(255,255,255,0.07); color: var(--text-primary); transform: translateY(-1px); }
.preset-btn.active {
    background: var(--accent-gradient); border-color: transparent; color: white;
    box-shadow: 0 2px 12px var(--accent-glow);
}
.preset-btn.active i { opacity: 1; }

/* Sliders */
.sliders { display: flex; flex-direction: column; gap: 1rem; }
.slider-group label {
    display: flex; justify-content: space-between; align-items: center;
    margin-bottom: 0.35rem; font-size: 0.82rem;
}
.slider-group label span:first-child { display: flex; align-items: center; gap: 0.4rem; color: var(--text-secondary); }
.slider-group label i { width: 13px; height: 13px; }
.val-display { font-weight: 700; color: var(--accent-secondary); font-size: 0.78rem; font-variant-numeric: tabular-nums; }
.slider-divider { height: 1px; background: var(--border-glass); margin: 0.25rem 0; }

input[type=range] { -webkit-appearance: none; width: 100%; background: transparent; }
input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none; height: 16px; width: 16px; border-radius: 50%;
    background: white; cursor: pointer; margin-top: -6px;
    box-shadow: 0 1px 6px rgba(0,0,0,0.3), 0 0 0 2px rgba(129,140,248,0.3);
    transition: box-shadow 0.2s;
}
input[type=range]::-webkit-slider-thumb:hover { box-shadow: 0 1px 6px rgba(0,0,0,0.3), 0 0 0 4px var(--accent-glow); }
input[type=range]::-webkit-slider-runnable-track {
    width: 100%; height: 4px; cursor: pointer; background: rgba(255,255,255,0.1); border-radius: 99px;
}
input[type=range]:focus { outline: none; }
input[type=range]:focus::-webkit-slider-runnable-track { background: rgba(129, 140, 248, 0.3); }

/* === Footer === */
.app-footer {
    display: flex; justify-content: space-between; align-items: center;
    padding: 0.75rem 0; font-size: 0.72rem; color: var(--text-muted);
    border-top: 1px solid var(--border-glass); margin-top: auto;
}

/* === Loading Overlay === */
.loading-overlay {
    position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(6, 10, 19, 0.92); backdrop-filter: blur(10px);
    z-index: 1000; display: flex; flex-direction: column; align-items: center; justify-content: center;
    gap: 1.25rem; transition: var(--transition-slow);
}
.loading-overlay.hidden { opacity: 0; pointer-events: none; }
.loader-ring {
    width: 48px; height: 48px; border: 3px solid rgba(255,255,255,0.08);
    border-top-color: var(--accent-secondary); border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
.loading-overlay p { font-size: 0.9rem; color: var(--text-secondary); }

@keyframes spin { 100% { transform: rotate(360deg); } }
@keyframes fadeIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }