:root {
    --bg-primary: #FFFFFF;
    --bg-secondary: #F8F9FA;
    --bg-tertiary: #F1F3F5;
    --text-primary: #1F2937;
    --text-secondary: #4B5563;
    --text-muted: #6B7280;
    --border-color: #E5E7EB;
    --accent: #667EEA;
    --accent-dark: #764BA2;
    --success: #10B981;
    --error: #EF4444;
    --warning: #F59E0B;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
}

[data-theme="dark"] {
    --bg-primary: #1F2937;
    --bg-secondary: #111827;
    --bg-tertiary: #0F172A;
    --text-primary: #F9FAFB;
    --text-secondary: #D1D5DB;
    --text-muted: #9CA3AF;
    --border-color: #374151;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.theme-toggle {
    position: fixed;
    bottom: 24px;
    left: 24px;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667EEA 0%, #764BA2 100%);
    color: white;
    border: none;
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.4);
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (min-width: 769px) {
    .theme-toggle {
        display: flex;
    }
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: 0 15px 40px rgba(102, 126, 234, 0.4);
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
}