:root {
            --primary: #4361ee;
            --secondary: #3f37c9;
            --accent: #4895ef;
            --light: #f8f9fa;
            --dark: #212529;
            --success: #4cc9f0;
            --font-base: 1rem;
            --font-scale: 1.2;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f5f7ff;
            color: var(--dark);
            line-height: 1.5;
            overflow-x: hidden;
            font-size: var(--font-base);
        }
        
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 1rem;
        }
        
        /* Header Styles */
        header {
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            color: white;
            padding: 1rem 0;
            text-align: center;
            border-radius: 0 0 1.25rem 1.25rem;
            box-shadow: 0 0.625rem 1.875rem rgba(67, 97, 238, 0.2);
        }
        
        .logo {
            font-size: clamp(1.5rem, 4vw, 2rem);
            font-weight: 800;
            margin-bottom: 0.25rem;
            letter-spacing: -0.5px;
        }
        
        .slogan {
            font-size: clamp(0.875rem, 2.5vw, 1rem);
            opacity: 0.9;
            margin-bottom: 0.5rem;
            padding: 0 1rem;
        }
        
        /* Calculator Container */
        .calculator-container {
            background: white;
            border-radius: 0.75rem;
            padding: 1.5rem;
            margin: 1.5rem auto;
            max-width: 600px;
            box-shadow: 0 0.25rem 0.75rem rgba(0, 0, 0, 0.05);
            border: 1px solid rgba(0, 0, 0, 0.03);
        }
        
        h1 {
            color: var(--primary);
            margin-bottom: 1.25rem;
            text-align: center;
            font-size: clamp(1.5rem, 4vw, 1.75rem);
        }
        
        .input-group {
            margin-bottom: 1.25rem;
        }
        
        label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 600;
            color: var(--dark);
            font-size: clamp(0.9375rem, 2.5vw, 1rem);
        }
        
        input[type="date"] {
            width: 100%;
            padding: 0.75rem 1rem;
            border: 1px solid #e9ecef;
            border-radius: 0.5rem;
            font-size: clamp(0.875rem, 2.5vw, 0.9375rem);
            transition: all 0.3s ease;
        }
        
        input[type="date"]:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
        }
        
        .btn {
            display: inline-block;
            background: var(--primary);
            color: white;
            padding: 0.75rem 1.25rem;
            border-radius: 2rem;
            text-decoration: none;
            font-weight: 600;
            transition: all 0.3s ease;
            border: none;
            cursor: pointer;
            width: 100%;
            text-align: center;
            font-size: clamp(0.875rem, 2.5vw, 0.9375rem);
        }
        
        .btn:hover {
            background: var(--secondary);
            transform: translateY(-0.125rem);
        }
        
        .btn-copy {
            background: var(--success);
            margin-top: 1rem;
            display: none;
        }
        
        .btn-copy:hover {
            background: #3ab4d9;
        }
        
        .result {
            margin-top: 1.5rem;
            padding: 1.25rem;
            background-color: #f8f9fa;
            border-radius: 0.75rem;
            display: none;
            animation: fadeIn 0.5s ease;
        }
        
        .result.active {
            display: block;
        }
        
        .result h2 {
            color: var(--dark);
            margin-bottom: 1.25rem;
            text-align: center;
            font-size: clamp(1.25rem, 3vw, 1.5rem);
        }
        
        .age-display {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 1rem;
        }
        
        .age-box {
            text-align: center;
            padding: 1rem;
            background: white;
            border-radius: 0.5rem;
            box-shadow: 0 0.125rem 0.375rem rgba(0, 0, 0, 0.05);
        }
        
        .age-value {
            font-size: clamp(1.5rem, 6vw, 2rem);
            font-weight: 700;
            color: var(--primary);
            margin-bottom: 0.5rem;
        }
        
        .age-label {
            font-size: clamp(0.75rem, 2vw, 0.8125rem);
            color: #666;
            text-transform: uppercase;
            letter-spacing: 1px;
        }
        
        /* Ad Containers */
        .ad-container {
            background-color: #f8f9fa;
            border-radius: 0.75rem;
            padding: 1rem;
            margin: 1.5rem 0;
            text-align: center;
            border: 1px dashed #ccc;
        }
        
        .ad-label {
            font-size: clamp(0.6875rem, 2vw, 0.75rem);
            color: #666;
            margin-bottom: 0.5rem;
            text-transform: uppercase;
            letter-spacing: 1px;
        }
        
        .ad-content {
            min-height: 90px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #999;
            font-size: clamp(0.75rem, 2vw, 0.8125rem);
        }
        
        /* Footer */
        footer {
            background: var(--dark);
            color: white;
            padding: 1.5rem 0;
            text-align: center;
            margin-top: 1.5rem;
        }
        
        .footer-logo {
            font-size: clamp(1.25rem, 3vw, 1.5rem);
            font-weight: 700;
            margin-bottom: 0.75rem;
        }
        
        .copyright {
            opacity: 0.7;
            font-size: clamp(0.75rem, 2vw, 0.8125rem);
        }
        
        /* Toast Notification */
        .toast {
            position: fixed;
            bottom: 1.5rem;
            right: 1.5rem;
            padding: 0.75rem 1.25rem;
            background-color: var(--success);
            color: white;
            border-radius: 0.5rem;
            box-shadow: 0 0.25rem 0.75rem rgba(0, 0, 0, 0.1);
            transform: translateY(100px);
            opacity: 0;
            transition: all 0.3s ease;
            z-index: 1000;
            font-size: clamp(0.8125rem, 2vw, 0.875rem);
        }
        
        .toast.show {
            transform: translateY(0);
            opacity: 1;
        }
        
        /* Animations */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        /* Responsive */
        @media (max-width: 768px) {
            .container {
                padding: 0 0.75rem;
            }
            
            .calculator-container {
                padding: 1.25rem;
            }
            
            .age-display {
                grid-template-columns: 1fr;
            }
        }
        
        @media (max-width: 480px) {
            .container {
                padding: 0 0.5rem;
            }
            
            .calculator-container {
                padding: 1rem;
            }
            
            .btn {
                padding: 0.625rem 1rem;
            }
        }
        
        /* Accessibility */
        a:focus, button:focus, input:focus {
            outline: 2px solid var(--accent);
            outline-offset: 2px;
        }
        
        /* Reduced motion */
        @media (prefers-reduced-motion: reduce) {
            * {
                animation-duration: 0.01ms !important;
                animation-iteration-count: 1 !important;
                transition-duration: 0.01ms !important;
                scroll-behavior: auto !important;
            }
        }