:root {
            --primary-blue: #2c5aa0;
            --light-blue: #a8d0ff;
            --snow-white: #ffffff;
            --ice-blue: #e6f3ff;
            --winter-gray: #5a6c7d;
            --accent-orange: #ff8c42;
            --shadow-blue: rgba(44, 90, 160, 0.1);
            --text-dark: #1a2332;
            --success-green: #28a745;
            --warning-orange: #ffc107;
            --danger-red: #dc3545;
        }

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

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            color: var(--text-dark);
            background: linear-gradient(135deg, var(--ice-blue) 0%, var(--light-blue) 100%);
            min-height: 100vh;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* Header Styles */
        header {
            background: var(--primary-blue);
            color: var(--snow-white);
            padding: 1rem 0;
            box-shadow: 0 2px 10px var(--shadow-blue);
            position: sticky;
            top: 0;
            z-index: 100;
        }

        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
        }

        .logo {
            font-size: 1.8rem;
            font-weight: bold;
            text-decoration: none;
            color: var(--snow-white);
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .nav {
            display: flex;
            gap: 2rem;
        }

        .nav a {
            color: var(--snow-white);
            text-decoration: none;
            transition: color 0.3s ease;
            font-weight: 500;
        }

        .nav a:hover {
            color: var(--light-blue);
        }

        /* Main Content */
        main {
            padding: 2rem 0;
            min-height: calc(100vh - 200px);
        }

        .hero {
            text-align: center;
            margin-bottom: 3rem;
        }

        .hero h1 {
            font-size: 2.8rem;
            color: var(--primary-blue);
            margin-bottom: 1rem;
            font-weight: 700;
        }

        .hero p {
            font-size: 1.3rem;
            color: var(--winter-gray);
            max-width: 650px;
            margin: 0 auto 1.5rem;
        }

        .hero-stats {
            display: flex;
            justify-content: center;
            gap: 3rem;
            margin-top: 2rem;
            flex-wrap: wrap;
        }

        .stat {
            text-align: center;
        }

        .stat-number {
            font-size: 2rem;
            font-weight: bold;
            color: var(--accent-orange);
            display: block;
        }

        .stat-label {
            font-size: 0.9rem;
            color: var(--winter-gray);
        }

        /* Calculator Section */
        .calculator-section {
            background: var(--snow-white);
            border-radius: 15px;
            padding: 2.5rem;
            box-shadow: 0 10px 30px var(--shadow-blue);
            margin-bottom: 3rem;
        }

        .calculator-title {
            text-align: center;
            color: var(--primary-blue);
            margin-bottom: 2rem;
            font-size: 2.2rem;
            font-weight: 600;
        }

        .form-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 1.5rem;
            margin-bottom: 2rem;
        }

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

        .form-group label {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--text-dark);
        }

        .form-group input,
        .form-group select {
            padding: 0.8rem;
            border: 2px solid var(--light-blue);
            border-radius: 8px;
            font-size: 1rem;
            transition: all 0.3s ease;
        }

        .form-group input:focus,
        .form-group select:focus {
            outline: none;
            border-color: var(--primary-blue);
            box-shadow: 0 0 0 3px rgba(44, 90, 160, 0.1);
        }

        .calculate-btn {
            background: var(--accent-orange);
            color: var(--snow-white);
            border: none;
            padding: 1.2rem 2.5rem;
            font-size: 1.2rem;
            font-weight: 600;
            border-radius: 8px;
            cursor: pointer;
            transition: all 0.3s ease;
            display: block;
            margin: 0 auto;
            box-shadow: 0 4px 15px rgba(255, 140, 66, 0.3);
        }

        .calculate-btn:hover {
            background: #e67a35;
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(255, 140, 66, 0.4);
        }

        /* Results Section */
        .results {
            text-align: center;
            margin-top: 2rem;
            padding: 2rem;
            background: linear-gradient(135deg, var(--ice-blue), var(--snow-white));
            border-radius: 15px;
            border: 2px solid var(--light-blue);
            display: none;
        }

        .results.show {
            display: block;
        }

        .probability {
            font-size: 3.5rem;
            font-weight: bold;
            color: var(--primary-blue);
            margin-bottom: 1rem;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
        }

        .probability-text {
            font-size: 1.3rem;
            color: var(--winter-gray);
            margin-bottom: 1.5rem;
            font-weight: 500;
        }

        .factors {
            text-align: left;
            max-width: 600px;
            margin: 0 auto;
        }

        .factors h4 {
            color: var(--primary-blue);
            margin-bottom: 1rem;
            font-size: 1.2rem;
        }

        .factors ul {
            list-style: none;
            padding-left: 0;
        }

        .factors li {
            padding: 0.8rem;
            margin-bottom: 0.5rem;
            background: var(--snow-white);
            border-radius: 8px;
            border-left: 4px solid var(--accent-orange);
            box-shadow: 0 2px 5px rgba(0,0,0,0.05);
        }

        /* Article Section */
        .article-section {
            background: var(--snow-white);
            border-radius: 15px;
            padding: 3rem;
            box-shadow: 0 10px 30px var(--shadow-blue);
            margin-bottom: 2rem;
        }

        .article-section h2 {
            color: var(--primary-blue);
            margin-bottom: 1.5rem;
            font-size: 2.5rem;
            font-weight: 600;
        }

        .article-section h3 {
            color: var(--primary-blue);
            margin: 2rem 0 1rem 0;
            font-size: 1.6rem;
            font-weight: 600;
        }

        .article-section h4 {
            color: var(--winter-gray);
            margin: 1.5rem 0 0.8rem 0;
            font-size: 1.3rem;
            font-weight: 600;
        }

        .article-section p {
            margin-bottom: 1.2rem;
            line-height: 1.8;
            font-size: 1.05rem;
        }

        .article-section ul, .article-section ol {
            margin-bottom: 1.5rem;
            padding-left: 2rem;
        }

        .article-section li {
            margin-bottom: 0.8rem;
            line-height: 1.7;
        }

        .highlight-box {
            background: var(--ice-blue);
            border-left: 4px solid var(--primary-blue);
            padding: 1.5rem;
            margin: 2rem 0;
            border-radius: 8px;
        }

        .highlight-box h4 {
            color: var(--primary-blue);
            margin-top: 0;
        }

        /* Footer */
        footer {
            background: var(--primary-blue);
            color: var(--snow-white);
            text-align: center;
            padding: 3rem 0;
            margin-top: 3rem;
        }

        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
            margin-bottom: 2rem;
        }

        .footer-section h4 {
            margin-bottom: 1rem;
            color: var(--light-blue);
            font-size: 1.2rem;
        }

        .footer-section a {
            color: var(--snow-white);
            text-decoration: none;
            display: block;
            margin-bottom: 0.8rem;
            transition: color 0.3s ease;
        }

        .footer-section a:hover {
            color: var(--light-blue);
        }

        .footer-bottom {
            border-top: 1px solid var(--light-blue);
            padding-top: 2rem;
            margin-top: 2rem;
        }

        /* Responsive Design */
        @media (max-width: 768px) {
            .hero h1 {
                font-size: 2.2rem;
            }

            .hero p {
                font-size: 1.1rem;
            }

            .hero-stats {
                gap: 1.5rem;
            }

            .calculator-section,
            .article-section {
                padding: 2rem;
            }

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

            .header-content {
                flex-direction: column;
                gap: 1rem;
            }

            .nav {
                flex-wrap: wrap;
                justify-content: center;
                gap: 1rem;
            }

            .probability {
                font-size: 2.8rem;
            }
        }

        @media (max-width: 480px) {
            .container {
                padding: 0 15px;
            }

            .hero h1 {
                font-size: 1.9rem;
            }

            .calculator-section,
            .article-section {
                padding: 1.5rem;
            }

            .probability {
                font-size: 2.3rem;
            }

            .calculate-btn {
                padding: 1rem 2rem;
                font-size: 1.1rem;
            }
        }

        /* Animation */
        .calculator-section,
        .article-section {
            animation: fadeInUp 0.6s ease-out;
        }

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

        .results {
            animation: slideIn 0.5s ease-out;
        }

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

        /* Loading animation */
        .loading {
            display: inline-block;
            width: 20px;
            height: 20px;
            border: 3px solid rgba(255,255,255,.3);
            border-radius: 50%;
            border-top-color: #fff;
            animation: spin 1s ease-in-out infinite;
        }

        @keyframes spin {
            to { transform: rotate(360deg); }
        }