* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            color: #2d3748;
            background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
            min-height: 100vh;
            margin: 0;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px;
        }
        
        .sr-only {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border: 0;
        }
        
        header {
            background: linear-gradient(135deg, #3182ce 0%, #38b2ac 50%, #48bb78 100%);
            text-align: center;
            margin-bottom: 40px;
            color: white;
            padding: 60px 20px;
            border-radius: 0 0 30px 30px;
            position: relative;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(56, 178, 172, 0.3);
        }
        
        header::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
            animation: float 20s infinite linear;
            pointer-events: none;
        }
        
        @keyframes float {
            0% { transform: translate(-50%, -50%) rotate(0deg); }
            100% { transform: translate(-50%, -50%) rotate(360deg); }
        }
        
        .header-content {
            position: relative;
            z-index: 2;
        }
        
        .header-icon {
            display: inline-block;
            font-size: 4rem;
            margin-bottom: 20px;
            animation: pulse 2s infinite;
            filter: drop-shadow(0 4px 8px rgba(0,0,0,0.3));
        }
        
        @keyframes pulse {
            0%, 100% { transform: scale(1); }
            50% { transform: scale(1.1); }
        }
        
        header h1 {
            font-size: 3.5rem;
            margin-bottom: 15px;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
            font-weight: 700;
            letter-spacing: -1px;
        }
        
        header p {
            font-size: 1.3rem;
            opacity: 0.95;
            max-width: 600px;
            margin: 0 auto;
            line-height: 1.5;
        }
        
        .nav-tabs {
            display: flex;
            justify-content: center;
            margin-bottom: 40px;
            background: rgba(255,255,255,0.9);
            border-radius: 15px;
            padding: 10px;
            backdrop-filter: blur(10px);
            gap: 10px;
            box-shadow: 0 8px 25px rgba(56, 178, 172, 0.15);
            border: 1px solid rgba(56, 178, 172, 0.2);
            role: tablist;
        }
        
        .nav-tab {
            padding: 15px 30px;
            background: rgba(56, 178, 172, 0.1);
            color: #2c5282;
            border: none;
            border-radius: 10px;
            cursor: pointer;
            transition: all 0.3s ease;
            font-weight: 600;
            font-size: 1rem;
            border: 2px solid transparent;
            role: tab;
        }
        
        .nav-tab:hover {
            background: rgba(56, 178, 172, 0.2);
            transform: translateY(-2px);
            border-color: rgba(56, 178, 172, 0.3);
        }
        
        .nav-tab:focus {
            outline: 3px solid rgba(56, 178, 172, 0.5);
            outline-offset: 2px;
        }
        
        .nav-tab.active {
            background: linear-gradient(135deg, #3182ce 0%, #38b2ac 100%);
            color: white;
            transform: translateY(-2px);
            box-shadow: 0 8px 20px rgba(49, 130, 206, 0.4);
            border-color: rgba(49, 130, 206, 0.5);
        }
        
        .content-section {
            display: none;
            background: linear-gradient(145deg, #f7fafc 0%, #edf2f7 100%);
            border-radius: 20px;
            padding: 40px;
            box-shadow: 0 20px 40px rgba(0,0,0,0.1);
            margin-bottom: 30px;
            border: 1px solid rgba(56, 178, 172, 0.1);
            role: tabpanel;
        }
        
        .content-section.active {
            display: block;
        }
        
        .grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 30px;
            margin: 30px 0;
        }
        
        .card {
            background: linear-gradient(145deg, #e6fffa 0%, #b2f5ea 100%);
            padding: 30px;
            border-radius: 15px;
            box-shadow: 0 10px 20px rgba(56, 178, 172, 0.15);
            transition: all 0.3s ease;
            border: 1px solid rgba(56, 178, 172, 0.2);
        }
        
        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 30px rgba(56, 178, 172, 0.25);
        }
        
        .card h3 {
            color: #2c5282;
            margin-bottom: 15px;
            font-size: 1.5rem;
        }
        
        .thermometer-types {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 20px;
            margin: 30px 0;
        }
        
        .thermometer {
            text-align: center;
            padding: 20px;
            background: linear-gradient(145deg, #ffffff 0%, #f0fff4 100%);
            border-radius: 15px;
            box-shadow: 0 5px 15px rgba(56, 178, 172, 0.1);
            transition: all 0.3s ease;
            border: 1px solid rgba(72, 187, 120, 0.2);
        }
        
        .thermometer:hover {
            transform: scale(1.05);
            box-shadow: 0 8px 25px rgba(56, 178, 172, 0.2);
        }
        
        .thermometer-icon {
            font-size: 3rem;
            margin-bottom: 10px;
        }
        
        .scale-comparison {
            margin: 30px 0;
        }
        
        .scale-bar {
            display: flex;
            height: 60px;
            border-radius: 30px;
            overflow: hidden;
            margin: 20px 0;
            box-shadow: 0 5px 15px rgba(0,0,0,0.2);
        }
        
        .celsius-bar {
            background: linear-gradient(90deg, #3182ce, #4299e1);
            flex: 5;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: bold;
        }
        
        .fahrenheit-bar {
            background: linear-gradient(90deg, #38b2ac, #4fd1c7);
            flex: 9;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: bold;
        }
        
        .input-container {
            transition: all 0.3s ease;
        }
        
        .input-container:hover {
            transform: translateY(-2px);
            box-shadow: 0 12px 25px rgba(56, 178, 172, 0.2);
        }
        
        input[type="number"], select {
            transition: all 0.3s ease;
        }
        
        input[type="number"]:focus, select:focus {
            outline: 3px solid rgba(56, 178, 172, 0.5);
            outline-offset: 2px;
            border-color: #38b2ac;
            background: white;
        }
        
        .conversion-result {
            font-size: 1.4rem;
            font-weight: 600;
            color: #2c5282;
            margin: 12px 0;
            padding: 12px;
            background: white;
            border-radius: 8px;
            border-left: 4px solid #38b2ac;
            box-shadow: 0 4px 10px rgba(56, 178, 172, 0.1);
        }
        
        .error-message {
            background: #fed7d7;
            color: #9b2c2c;
            padding: 12px;
            border-radius: 8px;
            border-left: 4px solid #e53e3e;
            margin: 10px 0;
            display: none;
        }
        
        .button-primary {
            background: linear-gradient(135deg, #48bb78 0%, #38b2ac 100%);
            color: white;
            border: none;
            padding: 15px 30px;
            border-radius: 10px;
            font-size: 1.2rem;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 8px 20px rgba(72, 187, 120, 0.3);
            font-weight: 600;
        }
        
        .button-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 12px 30px rgba(72, 187, 120, 0.4);
        }
        
        .button-primary:focus {
            outline: 3px solid rgba(72, 187, 120, 0.5);
            outline-offset: 2px;
        }
        
        .button-primary:disabled {
            opacity: 0.6;
            cursor: not-allowed;
            transform: none;
        }
        
        @media (max-width: 1150px) {

            .nav-tabs {
                /* flex-direction: column; */
                gap: 10px;
                margin-bottom: 30px;
            }
            
            .nav-tab {
                padding: 12px 20px;
                font-size: 0.8rem;
            }
            
        }

        @media (max-width: 900px) {

            .nav-tabs {
                /* flex-direction: column; */
                gap: 10px;
                margin-bottom: 30px;
            }
            
            .nav-tab {
                padding: 12px 20px;
                font-size: 0.6rem;
            }
            
        }

        @media (max-width: 765px) {
            .container {
                padding: 10px;
            }
            
            header {
                padding: 40px 20px;
                margin-bottom: 20px;
            }
            
            .header-icon {
                font-size: 3rem;
            }
            
            header h1 {
                font-size: 2.2rem;
            }
            
            header p {
                font-size: 1.1rem;
            }
            
            .nav-tabs {
                flex-direction: column;
                gap: 10px;
                margin-bottom: 30px;
            }
            
            .nav-tab {
                padding: 12px 20px;
                font-size: 0.9rem;
            }
            
            .content-section {
                padding: 20px;
            }
        }