/**
 * QMF Tools - Shared Stylesheet v2.0
 * Unified styling for QuizzMan Tools with optimized performance
 * Contains: CSS variables, animations, common components
 */

/* ============================================
   ROOT VARIABLES - Modern Color Palette
   ============================================ */
:root {
    /* Primary Colors - Modern Blue */
    --qmf-primary: #3b82f6;
    --qmf-primary-hover: #2563eb;
    --qmf-primary-light: rgba(59, 130, 246, 0.12);
    --qmf-primary-glow: rgba(59, 130, 246, 0.35);
    
    /* Accent Colors - Vibrant Purple */
    --qmf-secondary: #8b5cf6;
    --qmf-secondary-hover: #7c3aed;
    --qmf-secondary-light: rgba(139, 92, 246, 0.12);
    
    /* Semantic Colors */
    --qmf-success: #10b981;
    --qmf-success-light: rgba(16, 185, 129, 0.12);
    --qmf-danger: #ef4444;
    --qmf-danger-light: rgba(239, 68, 68, 0.12);
    --qmf-warning: #f59e0b;
    --qmf-warning-light: rgba(245, 158, 11, 0.12);
    --qmf-info: #0ea5e9;
    --qmf-info-light: rgba(14, 165, 233, 0.12);
    
    /* Light Theme */
    --qmf-bg: #f8fafc;
    --qmf-bg-gradient: linear-gradient(135deg, #f8fafc 0%, #e0f2fe 50%, #f0f9ff 100%);
    --qmf-card: #ffffff;
    --qmf-card-hover: #fafafa;
    --qmf-text: #1e293b;
    --qmf-text-secondary: #64748b;
    --qmf-text-muted: #94a3b8;
    --qmf-border: #e2e8f0;
    --qmf-border-hover: #cbd5e1;
    
    /* Shadows - Layered for depth */
    --qmf-shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --qmf-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
    --qmf-shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.06);
    --qmf-shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
    --qmf-shadow-glow: 0 0 20px var(--qmf-primary-glow);
    --qmf-shadow-inner: inset 0 2px 4px rgba(0, 0, 0, 0.04);
    
    /* Glassmorphism */
    --qmf-glass: rgba(255, 255, 255, 0.85);
    --qmf-glass-blur: blur(12px);
    --qmf-glass-border: rgba(255, 255, 255, 0.3);
    
    /* Layout */
    --qmf-radius-sm: 6px;
    --qmf-radius: 10px;
    --qmf-radius-lg: 16px;
    --qmf-radius-xl: 24px;
    
    /* Transitions - GPU optimized */
    --qmf-transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --qmf-transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --qmf-transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --qmf-spring: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    
    /* Spacing */
    --qmf-space-xs: 4px;
    --qmf-space-sm: 8px;
    --qmf-space-md: 16px;
    --qmf-space-lg: 24px;
    --qmf-space-xl: 32px;
}

/* Dark Theme Variables */
body.dark-mode {
    --qmf-primary-light: rgba(59, 130, 246, 0.2);
    --qmf-secondary-light: rgba(139, 92, 246, 0.2);
    
    --qmf-bg: #0f172a;
    --qmf-bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #1e1b4b 100%);
    --qmf-card: #1e293b;
    --qmf-card-hover: #334155;
    --qmf-text: #f1f5f9;
    --qmf-text-secondary: #94a3b8;
    --qmf-text-muted: #64748b;
    --qmf-border: #334155;
    --qmf-border-hover: #475569;
    
    --qmf-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --qmf-shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.25);
    --qmf-shadow-inner: inset 0 2px 4px rgba(0, 0, 0, 0.2);
    
    --qmf-glass: rgba(30, 41, 59, 0.85);
    --qmf-glass-border: rgba(255, 255, 255, 0.1);
}

/* ============================================
   GPU-ACCELERATED ANIMATIONS
   ============================================ */
@keyframes qmf-fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes qmf-slideUp {
    from { 
        opacity: 0; 
        transform: translateY(20px) translateZ(0); 
    }
    to { 
        opacity: 1; 
        transform: translateY(0) translateZ(0); 
    }
}

@keyframes qmf-slideDown {
    from { 
        opacity: 0; 
        transform: translateY(-20px) translateZ(0); 
    }
    to { 
        opacity: 1; 
        transform: translateY(0) translateZ(0); 
    }
}

@keyframes qmf-scaleIn {
    from { 
        opacity: 0; 
        transform: scale(0.95) translateZ(0); 
    }
    to { 
        opacity: 1; 
        transform: scale(1) translateZ(0); 
    }
}

@keyframes qmf-pulse {
    0%, 100% { 
        opacity: 1;
        transform: scale(1) translateZ(0);
    }
    50% { 
        opacity: 0.8;
        transform: scale(1.02) translateZ(0);
    }
}

@keyframes qmf-shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}

@keyframes qmf-spin {
    from { transform: rotate(0deg) translateZ(0); }
    to { transform: rotate(360deg) translateZ(0); }
}

@keyframes qmf-bounce {
    0%, 100% { transform: translateY(0) translateZ(0); }
    50% { transform: translateY(-6px) translateZ(0); }
}

@keyframes qmf-glow {
    0%, 100% { box-shadow: 0 0 8px var(--qmf-primary-glow); }
    50% { box-shadow: 0 0 20px var(--qmf-primary-glow); }
}

/* ============================================
   BASE STYLES - Performance Optimized
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--qmf-bg-gradient);
    color: var(--qmf-text);
    line-height: 1.6;
    min-height: 100vh;
    transition: background var(--qmf-transition), color var(--qmf-transition-fast);
}

/* Force GPU layer for smooth animations */
.qmf-gpu {
    transform: translateZ(0);
    will-change: transform, opacity;
    backface-visibility: hidden;
}

/* ============================================
   COMMON COMPONENTS
   ============================================ */

/* Cards */
.qmf-card {
    background: var(--qmf-card);
    border-radius: var(--qmf-radius-lg);
    box-shadow: var(--qmf-shadow);
    border: 1px solid var(--qmf-border);
    transition: transform var(--qmf-transition), box-shadow var(--qmf-transition), border-color var(--qmf-transition-fast);
}

.qmf-card:hover {
    box-shadow: var(--qmf-shadow-lg);
    border-color: var(--qmf-border-hover);
}

.qmf-card-interactive:hover {
    transform: translateY(-4px) translateZ(0);
}

/* Glass Card */
.qmf-glass-card {
    background: var(--qmf-glass);
    backdrop-filter: var(--qmf-glass-blur);
    -webkit-backdrop-filter: var(--qmf-glass-blur);
    border: 1px solid var(--qmf-glass-border);
    border-radius: var(--qmf-radius-lg);
    box-shadow: var(--qmf-shadow);
}

/* Buttons */
.qmf-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 600;
    border: none;
    border-radius: var(--qmf-radius);
    cursor: pointer;
    transition: all var(--qmf-transition);
    transform: translateZ(0);
    position: relative;
    overflow: hidden;
}

.qmf-btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, transparent, rgba(255,255,255,0.1));
    opacity: 0;
    transition: opacity var(--qmf-transition-fast);
}

.qmf-btn:hover::before {
    opacity: 1;
}

.qmf-btn:active {
    transform: scale(0.98) translateZ(0);
}

.qmf-btn-primary {
    background: linear-gradient(135deg, var(--qmf-primary), var(--qmf-primary-hover));
    color: white;
    box-shadow: 0 4px 14px rgba(59, 130, 246, 0.35);
}

.qmf-btn-primary:hover {
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.45);
    transform: translateY(-2px) translateZ(0);
}

.qmf-btn-secondary {
    background: var(--qmf-primary-light);
    color: var(--qmf-primary);
}

.qmf-btn-secondary:hover {
    background: rgba(59, 130, 246, 0.2);
}

.qmf-btn-ghost {
    background: transparent;
    color: var(--qmf-text-secondary);
    border: 1px solid var(--qmf-border);
}

.qmf-btn-ghost:hover {
    background: var(--qmf-card-hover);
    border-color: var(--qmf-border-hover);
    color: var(--qmf-text);
}

.qmf-btn-success {
    background: linear-gradient(135deg, var(--qmf-success), #059669);
    color: white;
    box-shadow: 0 4px 14px rgba(16, 185, 129, 0.35);
}

.qmf-btn-danger {
    background: linear-gradient(135deg, var(--qmf-danger), #dc2626);
    color: white;
    box-shadow: 0 4px 14px rgba(239, 68, 68, 0.35);
}

/* Icon Buttons */
.qmf-icon-btn {
    width: 40px;
    height: 40px;
    padding: 0;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--qmf-card);
    color: var(--qmf-text-secondary);
    border: 1px solid var(--qmf-border);
    cursor: pointer;
    transition: all var(--qmf-transition);
}

.qmf-icon-btn:hover {
    background: var(--qmf-primary);
    color: white;
    border-color: var(--qmf-primary);
    transform: scale(1.08) translateZ(0);
}

/* Inputs */
.qmf-input {
    width: 100%;
    padding: 12px 16px;
    font-size: 14px;
    background: var(--qmf-card);
    color: var(--qmf-text);
    border: 2px solid var(--qmf-border);
    border-radius: var(--qmf-radius);
    transition: border-color var(--qmf-transition-fast), box-shadow var(--qmf-transition-fast);
}

.qmf-input:focus {
    outline: none;
    border-color: var(--qmf-primary);
    box-shadow: 0 0 0 4px var(--qmf-primary-light);
}

.qmf-input::placeholder {
    color: var(--qmf-text-muted);
}

/* Select Dropdowns */
.qmf-select {
    appearance: none;
    -webkit-appearance: none;
    padding-right: 40px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2364748b' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    cursor: pointer;
}

/* Toolbar */
.qmf-toolbar {
    display: flex;
    align-items: center;
    gap: var(--qmf-space-sm);
    padding: var(--qmf-space-md);
    background: var(--qmf-glass);
    backdrop-filter: var(--qmf-glass-blur);
    border-bottom: 1px solid var(--qmf-border);
    flex-wrap: wrap;
}

.qmf-toolbar-group {
    display: flex;
    align-items: center;
    gap: 4px;
    padding-right: var(--qmf-space-md);
    border-right: 1px solid var(--qmf-border);
}

.qmf-toolbar-group:last-child {
    border-right: none;
    padding-right: 0;
}

.qmf-toolbar-btn {
    width: 36px;
    height: 36px;
    padding: 0;
    border: none;
    border-radius: var(--qmf-radius-sm);
    background: transparent;
    color: var(--qmf-text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--qmf-transition-fast);
}

.qmf-toolbar-btn:hover {
    background: var(--qmf-primary-light);
    color: var(--qmf-primary);
}

.qmf-toolbar-btn.active {
    background: var(--qmf-primary);
    color: white;
}

/* Progress Bar */
.qmf-progress {
    width: 100%;
    height: 8px;
    background: var(--qmf-border);
    border-radius: 999px;
    overflow: hidden;
}

.qmf-progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--qmf-primary), var(--qmf-secondary));
    border-radius: 999px;
    transition: width var(--qmf-transition);
    position: relative;
}

.qmf-progress-bar::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    animation: qmf-shimmer 2s infinite;
    background-size: 200% 100%;
}

/* Badge */
.qmf-badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    font-size: 12px;
    font-weight: 600;
    border-radius: 999px;
    background: var(--qmf-primary-light);
    color: var(--qmf-primary);
}

.qmf-badge-success {
    background: var(--qmf-success-light);
    color: var(--qmf-success);
}

.qmf-badge-warning {
    background: var(--qmf-warning-light);
    color: var(--qmf-warning);
}

.qmf-badge-danger {
    background: var(--qmf-danger-light);
    color: var(--qmf-danger);
}

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

/* Loading Spinner */
.qmf-spinner {
    width: 24px;
    height: 24px;
    border: 3px solid var(--qmf-border);
    border-top-color: var(--qmf-primary);
    border-radius: 50%;
    animation: qmf-spin 0.8s linear infinite;
}

/* Toast Notifications */
.qmf-toast-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.qmf-toast {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
    background: var(--qmf-card);
    border-radius: var(--qmf-radius);
    box-shadow: var(--qmf-shadow-lg);
    border-left: 4px solid var(--qmf-primary);
    animation: qmf-slideUp var(--qmf-transition);
    max-width: 400px;
}

.qmf-toast-success { border-left-color: var(--qmf-success); }
.qmf-toast-error { border-left-color: var(--qmf-danger); }
.qmf-toast-warning { border-left-color: var(--qmf-warning); }

/* Modal */
.qmf-modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--qmf-transition);
}

.qmf-modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.qmf-modal {
    background: var(--qmf-card);
    border-radius: var(--qmf-radius-xl);
    box-shadow: var(--qmf-shadow-xl);
    max-width: 90vw;
    max-height: 90vh;
    overflow: auto;
    transform: scale(0.9) translateY(20px);
    transition: transform var(--qmf-spring);
}

.qmf-modal-overlay.active .qmf-modal {
    transform: scale(1) translateY(0);
}

/* Tabs */
.qmf-tabs {
    display: flex;
    gap: 4px;
    padding: 4px;
    background: var(--qmf-border);
    border-radius: var(--qmf-radius);
}

.qmf-tab {
    flex: 1;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 500;
    color: var(--qmf-text-secondary);
    background: transparent;
    border: none;
    border-radius: var(--qmf-radius-sm);
    cursor: pointer;
    transition: all var(--qmf-transition-fast);
}

.qmf-tab:hover {
    color: var(--qmf-text);
}

.qmf-tab.active {
    background: var(--qmf-card);
    color: var(--qmf-primary);
    box-shadow: var(--qmf-shadow-sm);
}

/* Upload Area */
.qmf-upload-area {
    border: 2px dashed var(--qmf-border);
    border-radius: var(--qmf-radius-lg);
    padding: 48px 24px;
    text-align: center;
    cursor: pointer;
    transition: all var(--qmf-transition);
    position: relative;
    background: var(--qmf-card);
}

.qmf-upload-area:hover {
    border-color: var(--qmf-primary);
    background: var(--qmf-primary-light);
}

.qmf-upload-area.dragover {
    border-color: var(--qmf-primary);
    background: var(--qmf-primary-light);
    transform: scale(1.02) translateZ(0);
}

.qmf-upload-icon {
    font-size: 48px;
    color: var(--qmf-primary);
    margin-bottom: 16px;
}

/* Scrollbar */
.qmf-scrollbar::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

.qmf-scrollbar::-webkit-scrollbar-track {
    background: var(--qmf-border);
    border-radius: 4px;
}

.qmf-scrollbar::-webkit-scrollbar-thumb {
    background: var(--qmf-text-muted);
    border-radius: 4px;
}

.qmf-scrollbar::-webkit-scrollbar-thumb:hover {
    background: var(--qmf-text-secondary);
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.qmf-animate-in { animation: qmf-scaleIn var(--qmf-transition) forwards; }
.qmf-animate-up { animation: qmf-slideUp var(--qmf-transition) forwards; }
.qmf-animate-down { animation: qmf-slideDown var(--qmf-transition) forwards; }
.qmf-animate-pulse { animation: qmf-pulse 2s infinite; }
.qmf-animate-bounce { animation: qmf-bounce 1s infinite; }
.qmf-animate-glow { animation: qmf-glow 2s infinite; }

.qmf-hidden { display: none !important; }
.qmf-invisible { visibility: hidden; opacity: 0; }
.qmf-text-center { text-align: center; }
.qmf-text-muted { color: var(--qmf-text-muted); }

/* Focus visible for accessibility */
.qmf-focus-visible:focus-visible {
    outline: 2px solid var(--qmf-primary);
    outline-offset: 2px;
}

/* Responsive */
@media (max-width: 768px) {
    :root {
        --qmf-space-md: 12px;
        --qmf-space-lg: 18px;
        --qmf-space-xl: 24px;
    }
    
    .qmf-toolbar {
        gap: var(--qmf-space-xs);
        padding: var(--qmf-space-sm);
    }
    
    .qmf-toolbar-group {
        padding-right: var(--qmf-space-sm);
    }
    
    .qmf-btn {
        padding: 10px 18px;
        font-size: 13px;
    }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}