/* ============================================
   PARTICLE FLOW - Advanced Hand Gesture Art
   Premium Glass Morphism UI
   ============================================ */

:root {
    --primary: #6366f1;
    --primary-glow: rgba(99, 102, 241, 0.5);
    --accent: #22d3ee;
    --accent-glow: rgba(34, 211, 238, 0.5);
    --success: #10b981;
    --warning: #f59e0b;
    --glass-bg: rgba(15, 15, 25, 0.7);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-highlight: rgba(255, 255, 255, 0.12);
    --text-primary: rgba(255, 255, 255, 0.95);
    --text-secondary: rgba(255, 255, 255, 0.6);
    --text-muted: rgba(255, 255, 255, 0.35);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.15);
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html, body {
    overflow: hidden;
    background: #000;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--text-primary);
    width: 100%;
    height: 100%;
    touch-action: none;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    user-select: none;
}

#app {
    width: 100vw;
    height: 100vh;
    position: relative;
    overflow: hidden;
}

/* Canvas Container */
#canvas-container {
    position: absolute;
    inset: 0;
    z-index: 1;
}

#canvas-container canvas {
    display: block;
    width: 100% !important;
    height: 100% !important;
}

/* Hidden Elements */
#camera-feed {
    position: absolute;
    opacity: 0;
    pointer-events: none;
    width: 1px;
    height: 1px;
}

#debug-canvas {
    position: absolute;
    bottom: 24px;
    right: 24px;
    width: 280px;
    height: 210px;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    z-index: 200;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px) scale(0.95);
    transition: all var(--transition-slow);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    box-shadow: var(--shadow-glow);
}

#debug-canvas.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
}

/* ============================================
   LOADING SCREEN - Immersive Experience
   ============================================ */

#loading-screen {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, #0f0f1a 0%, #000 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: opacity 0.8s ease, visibility 0.8s ease;
}

#loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.loader-container {
    text-align: center;
}

.loader-orb {
    position: relative;
    width: 120px;
    height: 120px;
    margin: 0 auto 40px;
}

.orb-core {
    position: absolute;
    inset: 30px;
    background: radial-gradient(circle, var(--primary) 0%, transparent 70%);
    border-radius: 50%;
    animation: pulse-core 2s ease-in-out infinite;
}

.orb-ring {
    position: absolute;
    inset: 0;
    border: 2px solid transparent;
    border-radius: 50%;
}

.ring-1 {
    border-top-color: var(--primary);
    border-right-color: var(--accent);
    animation: spin 2s linear infinite;
}

.ring-2 {
    inset: 10px;
    border-bottom-color: var(--accent);
    border-left-color: var(--primary);
    animation: spin 3s linear infinite reverse;
}

.ring-3 {
    inset: 20px;
    border-top-color: rgba(255,255,255,0.3);
    animation: spin 4s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse-core { 0%, 100% { opacity: 0.5; transform: scale(0.8); } 50% { opacity: 1; transform: scale(1); } }

.loader-title {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 32px;
    font-weight: 600;
    background: linear-gradient(135deg, #fff 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.loader-subtitle {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.loader-progress {
    width: 200px;
    height: 3px;
    background: rgba(255,255,255,0.1);
    border-radius: 2px;
    margin: 0 auto 16px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    width: 30%;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    border-radius: 2px;
    animation: progress 2s ease-in-out infinite;
}

@keyframes progress { 0% { width: 0; margin-left: 0; } 50% { width: 60%; } 100% { width: 0; margin-left: 100%; } }

.loader-status {
    font-size: 12px;
    color: var(--text-muted);
}

/* ============================================
   GLASS PANEL - Floating UI Components
   ============================================ */

.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(24px) saturate(180%);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-glow), 0 8px 32px rgba(0,0,0,0.4);
}

.glass-panel.mini {
    border-radius: var(--radius-lg);
    padding: 12px 16px;
}

/* ============================================
   CONTROL PANEL - Main Settings
   ============================================ */

#control-panel {
    position: absolute;
    top: 24px;
    left: 24px;
    width: 280px;
    z-index: 100;
    transition: transform var(--transition-slow), opacity var(--transition-normal);
}

#control-panel.collapsed .panel-content {
    display: none;
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 1px solid var(--glass-border);
}

.panel-header h2 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 16px;
    font-weight: 500;
}

.icon-btn {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.icon-btn:hover {
    background: var(--glass-highlight);
    color: var(--text-primary);
}

.icon-btn svg {
    width: 18px;
    height: 18px;
    transition: transform var(--transition-normal);
}

#control-panel.collapsed .icon-btn svg {
    transform: rotate(180deg);
}

.panel-content {
    padding: 16px 20px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    max-height: 70vh;
    overflow-y: auto;
}

.panel-content::-webkit-scrollbar {
    width: 4px;
}

.panel-content::-webkit-scrollbar-thumb {
    background: var(--glass-highlight);
    border-radius: 2px;
}


/* Control Sections */
.control-section {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.section-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 11px;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.value-display {
    font-family: 'Space Grotesk', monospace;
    color: var(--accent);
}

/* Primary Button */
.primary-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    padding: 14px 20px;
    background: linear-gradient(135deg, var(--primary) 0%, #4f46e5 100%);
    border: none;
    border-radius: var(--radius-md);
    color: white;
    font-family: inherit;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: 0 4px 15px var(--primary-glow);
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px var(--primary-glow);
}

.primary-btn:active {
    transform: translateY(0);
}

.primary-btn.active {
    background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.4);
}

.primary-btn .btn-icon {
    width: 20px;
    height: 20px;
}

/* Secondary Button */
.secondary-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    padding: 12px 16px;
    background: var(--glass-highlight);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 13px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.secondary-btn:hover {
    background: rgba(255,255,255,0.15);
    color: var(--text-primary);
}

.secondary-btn.active {
    background: rgba(34, 211, 238, 0.2);
    border-color: var(--accent);
    color: var(--accent);
}

.secondary-btn .btn-icon {
    width: 16px;
    height: 16px;
}

/* Preset Grid */
.preset-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
}

.preset-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 12px 8px;
    background: var(--glass-highlight);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-family: inherit;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.preset-btn:hover {
    background: rgba(255,255,255,0.15);
    color: var(--text-primary);
}

.preset-btn.active {
    background: linear-gradient(135deg, rgba(99,102,241,0.3), rgba(34,211,238,0.2));
    border-color: var(--primary);
    color: var(--text-primary);
}

.preset-icon {
    font-size: 20px;
}

.preset-name {
    font-size: 10px;
    font-weight: 500;
}

/* Mode Selector */
.mode-selector {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.mode-chip {
    padding: 8px 14px;
    background: var(--glass-highlight);
    border: 1px solid transparent;
    border-radius: 20px;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 12px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.mode-chip:hover {
    background: rgba(255,255,255,0.15);
    color: var(--text-primary);
}

.mode-chip.active {
    background: var(--primary);
    color: white;
}

/* Styled Slider */
.styled-slider {
    width: 100%;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    background: rgba(255,255,255,0.1);
    border-radius: 3px;
    outline: none;
    cursor: pointer;
}

.styled-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 10px var(--primary-glow);
    transition: transform var(--transition-fast);
}

.styled-slider::-webkit-slider-thumb:hover {
    transform: scale(1.15);
}

/* Toggle Options */
.toggles {
    gap: 12px;
}

.toggle-option {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    font-size: 13px;
    color: var(--text-secondary);
}

.toggle-option input {
    display: none;
}

.toggle-switch {
    position: relative;
    width: 40px;
    height: 22px;
    background: rgba(255,255,255,0.1);
    border-radius: 11px;
    transition: background var(--transition-fast);
}

.toggle-switch::after {
    content: '';
    position: absolute;
    top: 3px;
    left: 3px;
    width: 16px;
    height: 16px;
    background: white;
    border-radius: 50%;
    transition: transform var(--transition-fast);
}

.toggle-option input:checked + .toggle-switch {
    background: var(--primary);
}

.toggle-option input:checked + .toggle-switch::after {
    transform: translateX(18px);
}

/* ============================================
   STATS HUD
   ============================================ */

#stats-hud {
    position: absolute;
    top: 24px;
    right: 24px;
    z-index: 100;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.stat-row {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: 'Space Grotesk', monospace;
    font-size: 13px;
}

.stat-icon {
    font-size: 12px;
}

.stat-row span:nth-child(2) {
    color: var(--accent);
    font-weight: 500;
    min-width: 45px;
}

.stat-unit {
    color: var(--text-muted);
    font-size: 11px;
}

/* ============================================
   HAND INDICATORS
   ============================================ */

#hand-indicators {
    position: absolute;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 16px;
    z-index: 100;
}

.hand-badge {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 18px;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 30px;
    opacity: 0.6;
    transition: all var(--transition-normal);
}

.hand-badge.active {
    opacity: 1;
    border-color: var(--accent);
    box-shadow: 0 0 20px var(--accent-glow);
}

.hand-icon {
    font-size: 18px;
}

.hand-label {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
}

.hand-status {
    font-family: 'Space Grotesk', monospace;
    font-size: 11px;
    color: var(--accent);
}

/* ============================================
   GESTURE FEEDBACK
   ============================================ */

#gesture-feedback {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-family: 'Space Grotesk', sans-serif;
    font-size: 48px;
    font-weight: 600;
    color: white;
    text-shadow: 0 0 40px var(--primary-glow);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
    z-index: 50;
}

#gesture-feedback.visible {
    opacity: 1;
    animation: gesture-pop 0.5s ease-out;
}

@keyframes gesture-pop {
    0% { transform: translate(-50%, -50%) scale(0.5); opacity: 0; }
    50% { transform: translate(-50%, -50%) scale(1.1); }
    100% { transform: translate(-50%, -50%) scale(1); opacity: 1; }
}

/* ============================================
   INSTRUCTIONS OVERLAY
   ============================================ */

#instructions-overlay {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 400px;
    max-width: 90vw;
    padding: 32px;
    text-align: center;
    z-index: 500;
    animation: fade-in 0.5s ease;
}

#instructions-overlay.hidden {
    display: none;
}

@keyframes fade-in {
    from { opacity: 0; transform: translate(-50%, -50%) scale(0.95); }
    to { opacity: 1; transform: translate(-50%, -50%) scale(1); }
}

.instructions-content h2 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 24px;
    margin-bottom: 8px;
}

.instructions-content > p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 24px;
}

.instruction-steps {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 24px;
    text-align: left;
}

.step {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    background: var(--glass-highlight);
    border-radius: var(--radius-md);
    font-size: 13px;
    color: var(--text-secondary);
}

.step-num {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary);
    border-radius: 50%;
    font-size: 12px;
    font-weight: 600;
    color: white;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

@media (max-width: 768px) {
    #control-panel {
        top: auto;
        bottom: 80px;
        left: 16px;
        right: 16px;
        width: auto;
    }

    .panel-content {
        max-height: 50vh;
    }

    .preset-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    #stats-hud {
        top: 16px;
        right: 16px;
    }

    #hand-indicators {
        bottom: 16px;
    }

    .hand-badge {
        padding: 8px 14px;
    }

    #debug-canvas {
        width: 180px;
        height: 135px;
        bottom: 16px;
        right: 16px;
    }

    #instructions-overlay {
        padding: 24px;
    }
}

@media (max-width: 480px) {
    .preset-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .mode-chip {
        padding: 6px 10px;
        font-size: 11px;
    }
}