* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Inter', sans-serif;
            background: linear-gradient(135deg, #144721 65%, #26540e 35%);
            min-height: 100vh;
            padding: 20px;
            position: relative;
            overflow-x: hidden;
        }

        body::before {
            content: '';
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="100" height="100" patternUnits="userSpaceOnUse"><path d="M 100 0 L 0 0 0 100" fill="none" stroke="rgba(255,255,255,0.05)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
            z-index: 0;
            pointer-events: none;
        }

        .container {
            max-width: 900px;
            margin: 0 auto;
            position: relative;
            z-index: 1;
        }

        .header {
            text-align: center;
            margin-bottom: 40px;
            animation: fadeInDown 0.8s ease;
        }

        @keyframes fadeInDown {
            from {
                opacity: 0;
                transform: translateY(-30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .header h1 {
            font-family: 'Poppins', sans-serif;
            font-size: clamp(2rem, 5vw, 3.5rem);
            font-weight: 700;
            color: #ffffff;
            margin-bottom: 12px;
            text-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
            letter-spacing: -1px;
        }

        .header p {
            font-size: clamp(0.95rem, 2vw, 1.15rem);
            color: rgba(255, 255, 255, 0.9);
            font-weight: 300;
            letter-spacing: 0.5px;
        }

        .content {
            background: rgba(255, 255, 255, 0.98);
            backdrop-filter: blur(10px);
            border-radius: 24px;
            padding: clamp(24px, 5vw, 48px);
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
            animation: fadeInUp 0.8s ease 0.2s both;
        }

        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .section {
            margin-bottom: 36px;
        }

        .section-title {
            font-family: 'Poppins', sans-serif;
            font-size: clamp(1.25rem, 3vw, 1.5rem);
            font-weight: 600;
            color: #2d3748;
            margin-bottom: 20px;
            padding-bottom: 12px;
            border-bottom: 3px solid #667eea;
            position: relative;
        }

        .section-title::after {
            content: '';
            position: absolute;
            bottom: -3px;
            left: 0;
            width: 60px;
            height: 3px;
            background: #764ba2;
            border-radius: 2px;
        }

        .form-row {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            margin-bottom: 20px;
        }

        .form-col, .form-group {
            display: flex;
            flex-direction: column;
        }

        label {
            font-size: clamp(0.9rem, 2vw, 0.95rem);
            font-weight: 500;
            color: #4a5568;
            margin-bottom: 8px;
            letter-spacing: 0.3px;
        }

        input[type="number"] {
            padding: 14px 18px;
            border: 2px solid #e2e8f0;
            border-radius: 12px;
            font-size: clamp(0.95rem, 2vw, 1rem);
            font-family: 'Inter', sans-serif;
            transition: all 0.3s ease;
            background: #ffffff;
            color: #2d3748;
        }

        input[type="number"]:focus {
            outline: none;
            border-color: #667eea;
            box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
            transform: translateY(-2px);
        }

        input[type="number"]::placeholder {
            color: #a0aec0;
        }

        .courses-container {
            margin-top: 24px;
            padding: 24px;
            background: linear-gradient(135deg, #f8f9ff 0%, #f0f4ff 100%);
            border-radius: 16px;
            border: 2px dashed #cbd5e0;
        }

        .courses-container h4 {
            font-family: 'Poppins', sans-serif;
            font-size: clamp(1.05rem, 2.5vw, 1.15rem);
            font-weight: 600;
            color: #2d3748;
            margin-bottom: 20px;
        }

        .course-item {
            display: flex;
            gap: 16px;
            align-items: flex-start;
            background: #ffffff;
            padding: 20px;
            border-radius: 12px;
            margin-bottom: 16px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
            transition: all 0.3s ease;
            animation: slideIn 0.5s ease;
        }

        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateX(-20px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }

        .course-item:hover {
            box-shadow: 0 6px 20px rgba(102, 126, 234, 0.15);
            transform: translateX(4px);
        }

        .course-number {
            min-width: 40px;
            height: 40px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 600;
            font-size: 1.1rem;
            flex-shrink: 0;
        }

        .course-inputs {
            flex: 1;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
            gap: 16px;
        }

        .grade-input input {
            width: 100%;
        }

        .credit-toggle {
            display: flex;
            gap: 8px;
            background: #f7fafc;
            padding: 4px;
            border-radius: 10px;
        }

        .credit-option {
            flex: 1;
            padding: 10px;
            text-align: center;
            border-radius: 8px;
            cursor: pointer;
            font-weight: 500;
            color: #4a5568;
            transition: all 0.3s ease;
            user-select: none;
        }

        .credit-option:hover {
            background: #edf2f7;
        }

        .credit-option.active {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
        }

        .calculate-btn {
            width: 100%;
            padding: 18px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border: none;
            border-radius: 14px;
            font-size: clamp(1rem, 2.5vw, 1.15rem);
            font-weight: 600;
            font-family: 'Poppins', sans-serif;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 8px 24px rgba(102, 126, 234, 0.3);
            letter-spacing: 0.5px;
            margin-top: 32px;
        }

        .calculate-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 12px 32px rgba(102, 126, 234, 0.4);
        }

        .calculate-btn:active {
            transform: translateY(-1px);
        }

        .result {
            margin-top: 32px;
            text-align: center;
            padding: 40px;
            background: linear-gradient(135deg, #f8f9ff 0%, #f0f4ff 100%);
            border-radius: 20px;
            border: 3px solid #667eea;
            opacity: 0;
            max-height: 0;
            overflow: hidden;
            transition: all 0.5s ease;
        }

        .result.show {
            opacity: 1;
            max-height: 400px;
            animation: bounceIn 0.6s ease;
        }

        @keyframes bounceIn {
            0% {
                transform: scale(0.8);
                opacity: 0;
            }
            50% {
                transform: scale(1.05);
            }
            100% {
                transform: scale(1);
                opacity: 1;
            }
        }

        .result h3 {
            font-family: 'Poppins', sans-serif;
            font-size: clamp(1.25rem, 3vw, 1.5rem);
            color: #2d3748;
            margin-bottom: 16px;
            font-weight: 600;
        }

        .cgpa-value {
            font-family: 'Poppins', sans-serif;
            font-size: clamp(3rem, 8vw, 4.5rem);
            font-weight: 700;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin: 20px 0;
            line-height: 1;
        }

        .result p {
            font-size: clamp(1rem, 2vw, 1.1rem);
            color: #4a5568;
            font-weight: 500;
            margin-top: 16px;
        }

        @media (max-width: 640px) {
            body {
                padding: 12px;
            }

            .content {
                padding: 24px 20px;
            }

            .course-item {
                flex-direction: column;
            }

            .course-inputs {
                grid-template-columns: 1fr;
            }

            .form-row {
                grid-template-columns: 1fr;
            }
        }

        @media (max-width: 380px) {
            .header h1 {
                font-size: 1.75rem;
            }

            .course-number {
                min-width: 36px;
                height: 36px;
                font-size: 1rem;
            }
        }