<style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

        :root {
            --primary: #4361ee;
            --secondary: #3f37c9;
            --accent: #4cc9f0;
            --light: #f8f9fa;
            --dark: #212529;
            --success: #4ade80;
            --warning: #facc15;
            --danger: #f87171;
            --gray: #6c757d;
            --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
            --transition: all 0.3s ease;
        }

        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #e4edf5 100%);
            color: var(--dark);
            line-height: 1.6;
            overflow-x: hidden;
            
        }

        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
           
        }
.btn-calculate {
    background: linear-gradient(to right, #2575fc, #6a11cb);
    color: white;
    border: none;
    padding: 16px 30px;
    font-size: 1.2rem;
    font-weight: 600;
    border-radius: 10px;
    cursor: pointer;
    width: 100%;
    margin-top: 10px;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 5px 15px rgba(37, 117, 252, 0.4);
}

.btn-calculate:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(37, 117, 252, 0.6);
}

.btn-calculate:active {
    transform: translateY(-1px);
}
.sub-header {
    background: linear-gradient(to right, #2575fc, #6a11cb);
    color: white;
    padding: 30px 40px;
    text-align: center;
	border-radius:20px;
}

h1 {
    font-size: 2.8rem;
    margin-bottom: 10px;
}
        /* Header Styles */
        header {
            background: white;
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 100;
            margin-bottom: 50px;
        }

        .header-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 0;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 12px;
            text-decoration: none;
        }

        .logo-icon {
            background: var(--primary);
            color: white;
            width: 40px;
            height: 40px;
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 20px;
            font-weight: bold;
        }

        .logo-text {
            font-size: 24px;
            font-weight: 800;
            background: linear-gradient(90deg, var(--primary), var(--accent));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        nav ul {
            display: flex;
            list-style: none;
            gap: 25px;
        }

        nav a {
            text-decoration: none;
            color: var(--dark);
            font-weight: 600;
            font-size: 16px;
            padding: 8px 12px;
            border-radius: 8px;
            transition: var(--transition);
            position: relative;
        }

        nav a:hover, nav a.active {
            color: var(--primary);
        }

        nav a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 3px;
            background: var(--primary);
            transition: var(--transition);
            border-radius: 10px;
        }

        nav a:hover::after, nav a.active::after {
            width: 100%;
        }

        .mobile-menu-btn {
            display: none;
            background: none;
            border: none;
            font-size: 24px;
            cursor: pointer;
            color: var(--dark);
        }

        /* Calculator Header */
        .calculator-header {
            text-align: center;
            padding:0px !important;
			margin-bottom:30px !important;
			
        }

        .calculator-header h1 {
            font-size: 42px;
            margin-bottom: 15px;
            background: #fff;
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .calculator-header p {
            font-size: 20px;
            color:#fff;
            max-width: 700px;
            margin: 0 auto;
        }

        /* Calculator Container */
        .calculator-container {
            background: white;
            border-radius: 20px;
            box-shadow: var(--shadow);
            overflow: hidden;
            margin-bottom: 40px !important;;
        }

        .calculator-content {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 30px;
            padding: 40px;
        }

        /* Input Section */
        .input-section {
            background: #f9fafb;
            border-radius: 16px;
            padding: 30px;
        }

        .input-section h2 {
            margin-bottom: 25px;
            color: var(--dark);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .input-section h2 i {
            color: var(--primary);
        }

        .input-group {
            margin-bottom: 25px;
        }

        .input-row {
            display: flex;
            gap: 15px;
            margin-bottom: 20px;
            align-items: center;
        }

        .input-row label {
            width: 150px;
            font-weight: 500;
            color: var(--dark);
        }

        .input-row input {
            flex: 1;
            padding: 12px 15px;
            border: 2px solid #e1e5eb;
            border-radius: 10px;
            font-size: 16px;
            transition: var(--transition);
        }

        .input-row input:focus {
            border-color: var(--primary);
            outline: none;
        }

        .weight-input {
            width: 80px;
            text-align: center;
        }

        .add-category {
            display: flex;
            align-items: center;
            gap: 10px;
            color: var(--primary);
            font-weight: 600;
            cursor: pointer;
            margin-top: 15px;
            padding: 10px 0;
        }

        .add-category:hover {
            color: var(--secondary);
        }

        /* Results Section */
        .results-section {
            padding: 30px;
        }

        .results-section h2 {
            margin-bottom: 25px;
            color: var(--dark);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .results-section h2 i {
            color: var(--primary);
        }

        .grade-card {
            background: linear-gradient(135deg, var(--primary), var(--accent));
            border-radius: 16px;
            padding: 30px;
            text-align: center;
            color: white;
            margin-bottom: 30px;
            box-shadow: 0 10px 20px rgba(67, 97, 238, 0.2);
        }

        .grade-card h3 {
            font-size: 20px;
            margin-bottom: 15px;
            font-weight: 500;
        }

        .grade-value {
            font-size: 64px;
            font-weight: 800;
            margin-bottom: 15px;
        }

        .letter-grade {
            font-size: 36px;
            font-weight: 700;
            background: rgba(255, 255, 255, 0.2);
            display: inline-block;
            padding: 5px 30px;
            border-radius: 50px;
        }

        .result-details {
            background: var(--light);
            border-radius: 16px;
            padding: 25px;
            margin-bottom: 30px;
        }

        .result-item {
            display: flex;
            justify-content: space-between;
            padding: 15px 0;
            border-bottom: 1px solid #e1e5eb;
        }

        .result-item:last-child {
            border-bottom: none;
        }

        .result-item .label {
            color: var(--gray);
        }

        .result-item .value {
            font-weight: 700;
            color: var(--dark);
        }

        .chart-container {
            height: 250px;
            margin-top: 20px;
        }

        /* Grade Scale */
        .grade-scale {
            background: white;
            border-radius: 16px;
            padding: 40px !important;
            box-shadow: var(--shadow);
        }

        .grade-scale h2 {
            margin-bottom: 25px;
            color: var(--dark);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .grade-scale h2 i {
            color: var(--primary);
        }

        .scale-table {
            width: 100%;
            border-collapse: collapse;
        }

        .scale-table th {
            background: var(--light);
            padding: 15px;
            text-align: left;
            color: var(--dark);
            font-weight: 600;
        }

        .scale-table td {
            padding: 15px;
            border-bottom: 1px solid #e1e5eb;
        }

        .scale-table tr:last-child td {
            border-bottom: none;
        }

        .grade-a { background-color: rgba(74, 222, 128, 0.1); }
        .grade-b { background-color: rgba(250, 204, 21, 0.1); }
        .grade-c { background-color: rgba(251, 146, 60, 0.1); }
        .grade-d { background-color: rgba(248, 113, 113, 0.1); }
        .grade-f { background-color: rgba(220, 38, 38, 0.1); }

        /* Footer */
        footer {
            background: var(--dark);
            color: white;
            padding: 60px 0 20px;
            margin-top: 60px;
        }

        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 40px;
            margin-bottom: 40px;
        }

        .footer-column h3 {
            font-size: 20px;
            margin-bottom: 20px;
            position: relative;
            padding-bottom: 10px;
        }

        .footer-column h3::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 50px;
            height: 3px;
            background: var(--primary);
            border-radius: 10px;
        }

        .footer-column ul {
            list-style: none;
        }

        .footer-column ul li {
            margin-bottom: 12px;
        }

        .footer-column a {
            color: #b1b1b1;
            text-decoration: none;
            transition: var(--transition);
        }

        .footer-column a:hover {
            color: white;
            padding-left: 5px;
        }

        .copyright {
            text-align: center;
            padding-top: 20px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            color: #b1b1b1;
            font-size: 14px;
        }

        /* Responsive Design */
        @media (max-width: 900px) {
            .calculator-content {
                grid-template-columns: 1fr;
            }
            
            nav ul {
                gap: 15px;
            }
        }

        @media (max-width: 768px) {
            .mobile-menu-btn {
                display: block;
            }
            
            nav ul {
                display: none;
                position: absolute;
                top: 70px;
                left: 0;
                right: 0;
                background: white;
                flex-direction: column;
                padding: 20px;
                box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
                gap: 10px;
            }
            
            nav ul.show {
                display: flex;
            }
            
            .calculator-header h1 {
                font-size: 32px;
            }
            
            .input-row {
                flex-direction: column;
                align-items: flex-start;
                gap: 8px;
            }
            
            .input-row label {
                width: 100%;
            }
            
            .input-row input {
                width: 100%;
            }
        }

        @media (max-width: 480px) {
			    .calculator-content {
            padding: 0px;
        }
            .calculator-header h1 {
                font-size: 28px;
            }
            
            .grade-value {
                font-size: 48px;
            }
            
            .letter-grade {
                font-size: 28px;
            }
			        .calculator-header p {
            font-size: 16px;
					}
        }
    </style>