/* CSS Variables */
:root {
    /* Colors */
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    --primary-200: #bfdbfe;
    --primary-300: #93c5fd;
    --primary-400: #60a5fa;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;
    --primary-800: #1e40af;
    --primary-900: #1e3a8a;
    
    --secondary-50: #f8fafc;
    --secondary-100: #f1f5f9;
    --secondary-200: #e2e8f0;
    --secondary-300: #cbd5e1;
    --secondary-400: #94a3b8;
    --secondary-500: #64748b;
    --secondary-600: #475569;
    --secondary-700: #334155;
    --secondary-800: #1e293b;
    --secondary-900: #0f172a;
    
    --success-50: #f0fdf4;
    --success-100: #dcfce7;
    --success-200: #bbf7d0;
    --success-300: #86efac;
    --success-400: #4ade80;
    --success-500: #22c55e;
    --success-600: #16a34a;
    --success-700: #15803d;
    --success-800: #166534;
    --success-900: #14532d;
    
    --warning-50: #fffbeb;
    --warning-100: #fef3c7;
    --warning-200: #fde68a;
    --warning-300: #fcd34d;
    --warning-400: #fbbf24;
    --warning-500: #f59e0b;
    --warning-600: #d97706;
    --warning-700: #b45309;
    --warning-800: #92400e;
    --warning-900: #78350f;
    
    --danger-50: #fef2f2;
    --danger-100: #fee2e2;
    --danger-200: #fecaca;
    --danger-300: #fca5a5;
    --danger-400: #f87171;
    --danger-500: #ef4444;
    --danger-600: #dc2626;
    --danger-700: #b91c1c;
    --danger-800: #991b1b;
    --danger-900: #7f1d1d;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* Spacing */
    --spacing-1: 0.25rem;
    --spacing-2: 0.5rem;
    --spacing-3: 0.75rem;
    --spacing-4: 1rem;
    --spacing-5: 1.25rem;
    --spacing-6: 1.5rem;
    --spacing-8: 2rem;
    --spacing-10: 2.5rem;
    --spacing-12: 3rem;
    --spacing-16: 4rem;
    --spacing-20: 5rem;
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-xl: 0.75rem;
    --radius-2xl: 1rem;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-family: var(--font-family);
    font-size: 16px;
    line-height: 1.5;
    -webkit-text-size-adjust: 100%;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    background-color: var(--secondary-50);
    color: var(--secondary-900);
    min-height: 100vh;
    overflow-x: hidden;
}

/* Loading Screen */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-600), var(--primary-800));
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    animation: fadeIn 0.5s ease-in-out;
}

.loading-content {
    text-align: center;
    color: white;
}

.loading-logo {
    margin-bottom: var(--spacing-6);
}

.logo-icon {
    font-size: 4rem;
    animation: bounce 2s infinite;
}

.loading-title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    margin-bottom: var(--spacing-2);
}

.loading-subtitle {
    font-size: var(--font-size-lg);
    opacity: 0.8;
    margin-bottom: var(--spacing-8);
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top: 3px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

/* Login Screen */
.login-screen {
    min-height: 100vh;
    background: linear-gradient(135deg, var(--primary-600), var(--primary-800));
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-4);
}

.login-container {
    background: white;
    border-radius: var(--radius-2xl);
    padding: var(--spacing-8);
    width: 100%;
    max-width: 400px;
    box-shadow: var(--shadow-xl);
    animation: slideUp 0.5s ease-out;
}

.login-header {
    text-align: center;
    margin-bottom: var(--spacing-8);
}

.login-logo {
    margin-bottom: var(--spacing-4);
}

.login-header h1 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--secondary-900);
    margin-bottom: var(--spacing-2);
}

.login-header p {
    color: var(--secondary-600);
    font-size: var(--font-size-lg);
}

/* App Container */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: var(--secondary-50);
}

/* Header */
.app-header {
    background: white;
    border-bottom: 1px solid var(--secondary-200);
    padding: var(--spacing-4);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-left h1 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--secondary-900);
    margin-bottom: var(--spacing-1);
}

.header-left p {
    font-size: var(--font-size-sm);
    color: var(--secondary-600);
}

.header-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
}

.header-btn {
    width: 40px;
    height: 40px;
    border: none;
    border-radius: var(--radius-lg);
    background: var(--secondary-100);
    color: var(--secondary-700);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition-fast);
    position: relative;
}

.header-btn:hover {
    background: var(--secondary-200);
}

.header-btn.primary {
    background: var(--primary-600);
    color: white;
}

.header-btn.primary:hover {
    background: var(--primary-700);
}

/* Main Content */
.app-main {
    flex: 1;
    padding: var(--spacing-4);
    padding-bottom: 80px; /* Space for bottom nav */
}

.screen-content {
    animation: fadeIn 0.3s ease-in-out;
}

/* Dashboard */
.dashboard-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-4);
    margin-bottom: var(--spacing-6);
}

.stat-card {
    background: white;
    border-radius: var(--radius-xl);
    padding: var(--spacing-4);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    transition: var(--transition-fast);
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.stat-icon {
    font-size: 2rem;
    width: 50px;
    height: 50px;
    border-radius: var(--radius-lg);
    background: var(--primary-100);
    color: var(--primary-600);
    display: flex;
    align-items: center;
    justify-content: center;
}

.stat-content h3 {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--secondary-900);
    margin-bottom: var(--spacing-1);
}

.stat-content p {
    font-size: var(--font-size-sm);
    color: var(--secondary-600);
}

.dashboard-sections {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
}

.section-card {
    background: white;
    border-radius: var(--radius-xl);
    padding: var(--spacing-4);
    box-shadow: var(--shadow-md);
}

.section-card h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--secondary-900);
    margin-bottom: var(--spacing-4);
}

.quick-actions {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-3);
}

.action-btn {
    background: var(--secondary-100);
    border: none;
    border-radius: var(--radius-lg);
    padding: var(--spacing-4);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-2);
    cursor: pointer;
    transition: var(--transition-fast);
}

.action-btn:hover {
    background: var(--secondary-200);
    transform: translateY(-1px);
}

.action-icon {
    font-size: 1.5rem;
}

.action-btn span:last-child {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--secondary-700);
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: white;
    border-top: 1px solid var(--secondary-200);
    display: flex;
    padding: var(--spacing-2);
    box-shadow: var(--shadow-lg);
    z-index: 100;
}

.nav-item {
    flex: 1;
    background: none;
    border: none;
    padding: var(--spacing-2);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-1);
    cursor: pointer;
    transition: var(--transition-fast);
    border-radius: var(--radius-lg);
}

.nav-item:hover {
    background: var(--secondary-100);
}

.nav-item.active {
    background: var(--primary-100);
    color: var(--primary-600);
}

.nav-icon {
    font-size: 1.25rem;
}

.nav-label {
    font-size: var(--font-size-xs);
    font-weight: 500;
}

/* Responsive Design */
@media (min-width: 768px) {
    .dashboard-stats {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .quick-actions {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .app-main {
        max-width: 768px;
        margin: 0 auto;
    }
}

@media (min-width: 1024px) {
    .app-main {
        max-width: 1024px;
    }
}