frontend/css/style.css

:root {
    --bg-dark: #07070f;
    --bg-panel: rgba(20, 20, 35, 0.4);
    --primary: #7c3aed;
    --primary-hover: #9353d3;
    --primary-glow: rgba(124, 58, 237, 0.5);
    --secondary: #2563eb;
    --secondary-glow: rgba(37, 99, 235, 0.5);
    --accent: #f43f5e;
    --accent-glow: rgba(244, 63, 94, 0.5);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --text-dim: #64748b;
    --border: rgba(255, 255, 255, 0.08);
    --success: #10b981;
    --danger: #ef4444;
    --font-family: 'Inter', -apple-system, sans-serif;
    --transition-smooth: cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-family);
    background: var(--bg-dark);
    color: var(--text-main);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

#particles-canvas {
    position: fixed;
    top: 0; left: 0;
    width: 100vw; height: 100vh;
    z-index: -1;
    opacity: 0.6;
    pointer-events: none;
}

.text-gradient {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.glass-panel {
    background: var(--bg-panel);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
    font-family: var(--font-family);
    color: white;
}

.btn-glow {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    box-shadow: 0 0 20px var(--primary-glow);
}

.btn-glow:hover {
    box-shadow: 0 0 30px var(--secondary-glow);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-main);
}

.btn-outline:hover {
    border-color: var(--text-muted);
    background: rgba(255, 255, 255, 0.05);
}

.btn-danger {
    background: transparent;
    border: 1px solid var(--danger);
    color: var(--danger);
}
.btn-danger:hover {
    background: var(--danger);
    color: white;
    box-shadow: 0 0 20px rgba(239, 68, 68, 0.4);
}

/* Nav */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 5%;
    position: sticky;
    top: 0;
    z-index: 100;
    transition: all 0.3s ease;
}

nav.scrolled {
    background: rgba(7, 7, 15, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    padding: 1rem 5%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--text-main);
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s ease;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--text-main);
}

/* Animations */
.animate-fade-in {
    animation: fadeIn 0.8s ease forwards;
}

.animate-slide-up {
    opacity: 0;
    transform: translateY(20px);
    animation: slideUp 0.8s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

.stagger-1 { animation-delay: 0.1s; }
.stagger-2 { animation-delay: 0.2s; }
.stagger-3 { animation-delay: 0.3s; }

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Spinner Orb */
.spinner-orb {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    margin: 0 auto;
    animation: pulseOrb 2s infinite ease-in-out, rotateOrb 3s infinite linear;
    box-shadow: 0 0 30px var(--primary-glow);
}

@keyframes pulseOrb {
    0%, 100% { transform: scale(0.8); filter: hue-rotate(0deg); }
    50% { transform: scale(1.1); filter: hue-rotate(45deg); box-shadow: 0 0 50px var(--secondary-glow); }
}

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

/* Orb Player Canvas */
.orb-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    margin-top: 1rem;
}

.orb-canvas-wrapper {
    width: 150px;
    height: 150px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

#orb-canvas {
    width: 100%;
    height: 100%;
    filter: drop-shadow(0 0 15px var(--primary-glow));
}

.orb-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    width: 100%;
    max-width: 400px;
    background: rgba(0,0,0,0.4);
    padding: 0.8rem 1.5rem;
    border-radius: 100px;
    border: 1px solid var(--border);
}

.orb-play-btn {
    background: transparent;
    border: none;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s;
}

.orb-play-btn:hover {
    transform: scale(1.1);
    color: var(--primary-hover);
}

.orb-seek {
    flex: 1;
    -webkit-appearance: none;
    height: 4px;
    background: rgba(255,255,255,0.1);
    border-radius: 2px;
    outline: none;
}

.orb-seek::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--primary);
    box-shadow: 0 0 10px var(--primary-glow);
    cursor: pointer;
}

.orb-time {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-variant-numeric: tabular-nums;
}

/* Drop Zone Styles */
.drop-zone {
    border: 2px dashed var(--border);
    border-radius: 16px;
    padding: 2.5rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background: rgba(255, 255, 255, 0.02);
    position: relative;
    overflow: hidden;
}

.drop-zone:hover, .drop-zone.dragover {
    border-color: var(--primary);
    background: rgba(124, 58, 237, 0.05);
    box-shadow: 0 0 20px rgba(124, 58, 237, 0.1);
}

.drop-zone-icon {
    width: 48px;
    height: 48px;
    color: var(--text-muted);
    margin-bottom: 1rem;
    transition: all 0.3s ease;
}

.drop-zone:hover .drop-zone-icon {
    color: var(--primary);
    transform: translateY(-5px);
}

.drop-zone h4 {
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.drop-zone p {
    color: var(--text-dim);
    font-size: 0.9rem;
}

.drop-zone.has-file {
    border-color: var(--success);
    background: rgba(16, 185, 129, 0.05);
}

.drop-zone.has-file .drop-zone-icon {
    color: var(--success);
}

#reference-file-name {
    margin-top: 1rem;
    font-weight: 600;
    color: var(--success);
    font-size: 0.9rem;
}