* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        :root {
            --primary: #ff6600;
            --primary-dark: #cc5200;
            --secondary: #0b3d91;
            --secondary-light: #1e56c7;
            --light: #f8f9fa;
            --dark: #212529;
            --gray: #6c757d;
            --gray-light: #e9ecef;
            --success: #28a745;
            --warning: #ffc107;
            --danger: #dc3545;
            --radius: 8px;
            --shadow: 0 4px 12px rgba(0,0,0,0.08);
            --transition: all 0.3s ease;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
            line-height: 1.6;
            color: var(--dark);
            background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
            min-height: 100vh;
            overflow-x: hidden;
        }
        h1, h2, h3, h4 {
            font-weight: 700;
            line-height: 1.2;
            margin-bottom: 1rem;
            color: var(--secondary);
        }
        h1 {
            font-size: clamp(2rem, 5vw, 3.2rem);
            margin-bottom: 1.5rem;
        }
        h2 {
            font-size: clamp(1.5rem, 4vw, 2.2rem);
            border-left: 5px solid var(--primary);
            padding-left: 1rem;
            margin-top: 3rem;
        }
        h3 {
            font-size: clamp(1.2rem, 3vw, 1.6rem);
            color: var(--dark);
            margin-top: 2rem;
        }
        p {
            margin-bottom: 1.5rem;
            font-size: 1.05rem;
        }
        a {
            color: var(--secondary);
            text-decoration: none;
            transition: var(--transition);
        }
        a:hover {
            color: var(--primary);
            text-decoration: underline;
        }
        strong {
            color: var(--primary);
            font-weight: 700;
        }
        em {
            color: var(--gray);
            font-style: italic;
        }
        blockquote {
            border-left: 4px solid var(--primary);
            padding: 1.5rem;
            margin: 2rem 0;
            background: white;
            border-radius: 0 var(--radius) var(--radius) 0;
            box-shadow: var(--shadow);
            font-style: italic;
        }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 1.5rem;
        }
        .flex {
            display: flex;
        }
        .grid {
            display: grid;
        }
        .btn {
            display: inline-block;
            padding: 0.8rem 1.8rem;
            background: var(--primary);
            color: white;
            border: none;
            border-radius: var(--radius);
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            text-align: center;
        }
        .btn:hover {
            background: var(--primary-dark);
            transform: translateY(-2px);
            box-shadow: var(--shadow);
            text-decoration: none;
        }
        .card {
            background: white;
            border-radius: var(--radius);
            padding: 2rem;
            box-shadow: var(--shadow);
            margin-bottom: 2rem;
        }
        header {
            background: white;
            box-shadow: 0 2px 15px rgba(0,0,0,0.1);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        .header-top {
            padding: 1rem 0;
            border-bottom: 1px solid var(--gray-light);
        }
        .logo {
            font-size: 1.8rem;
            font-weight: 900;
            color: var(--secondary);
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        .logo i {
            color: var(--primary);
            font-size: 2rem;
        }
        .logo:hover {
            text-decoration: none;
            color: var(--secondary);
        }
        .breadcrumb {
            padding: 1rem 0;
            background: var(--gray-light);
            font-size: 0.9rem;
        }
        .breadcrumb ol {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 0.5rem;
        }
        .breadcrumb li:not(:last-child)::after {
            content: "›";
            margin-left: 0.5rem;
            color: var(--gray);
        }
        nav {
            padding: 1rem 0;
        }
        .nav-desktop {
            display: none;
        }
        .nav-mobile {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .hamburger {
            background: none;
            border: none;
            font-size: 1.5rem;
            color: var(--secondary);
            cursor: pointer;
            padding: 0.5rem;
        }
        .mobile-menu {
            position: fixed;
            top: 0;
            right: -100%;
            width: 280px;
            height: 100vh;
            background: white;
            box-shadow: -5px 0 15px rgba(0,0,0,0.1);
            padding: 2rem;
            transition: right 0.3s ease;
            z-index: 1001;
            overflow-y: auto;
        }
        .mobile-menu.active {
            right: 0;
        }
        .mobile-menu-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 2rem;
            padding-bottom: 1rem;
            border-bottom: 1px solid var(--gray-light);
        }
        .close-menu {
            background: none;
            border: none;
            font-size: 1.5rem;
            color: var(--gray);
            cursor: pointer;
        }
        .nav-list {
            list-style: none;
        }
        .nav-list li {
            margin-bottom: 1rem;
        }
        .nav-list a {
            display: block;
            padding: 0.8rem;
            border-radius: var(--radius);
            color: var(--dark);
            font-weight: 500;
        }
        .nav-list a:hover {
            background: var(--gray-light);
            text-decoration: none;
        }
        .nav-list a i {
            margin-right: 0.8rem;
            width: 20px;
            text-align: center;
        }
        .overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0,0,0,0.5);
            z-index: 1000;
            display: none;
        }
        .overlay.active {
            display: block;
        }
        main {
            padding: 2rem 0;
        }
        .article-header {
            text-align: center;
            margin-bottom: 3rem;
            padding: 2rem;
            background: linear-gradient(135deg, var(--secondary) 0%, var(--secondary-light) 100%);
            color: white;
            border-radius: var(--radius);
        }
        .article-header h1 {
            color: white;
            border: none;
            padding: 0;
        }
        .meta-info {
            display: flex;
            justify-content: center;
            gap: 2rem;
            margin-top: 1.5rem;
            flex-wrap: wrap;
        }
        .meta-item {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            font-size: 0.9rem;
        }
        .meta-item i {
            color: var(--warning);
        }
        .calculator-widget {
            background: linear-gradient(135deg, #ff6600 0%, #ff8533 100%);
            color: white;
            padding: 2rem;
            border-radius: var(--radius);
            margin: 3rem 0;
            box-shadow: var(--shadow);
        }
        .calculator-widget h2 {
            color: white;
            border-left: 5px solid white;
            margin-top: 0;
        }
        .calculator-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 1.5rem;
            margin-top: 1.5rem;
        }
        .calculator-input-group {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
        }
        .calculator-input-group label {
            font-weight: 600;
        }
        .calculator-input-group input,
        .calculator-input-group select {
            padding: 0.8rem;
            border: none;
            border-radius: var(--radius);
            font-size: 1rem;
        }
        .calculator-results {
            background: rgba(255,255,255,0.1);
            padding: 1.5rem;
            border-radius: var(--radius);
            margin-top: 1.5rem;
            display: none;
        }
        .calculator-results.active {
            display: block;
        }
        .result-item {
            display: flex;
            justify-content: space-between;
            padding: 0.8rem 0;
            border-bottom: 1px solid rgba(255,255,255,0.2);
        }
        .result-item:last-child {
            border-bottom: none;
            font-weight: 700;
            font-size: 1.2rem;
        }
        .search-box {
            margin: 2rem 0;
            background: white;
            padding: 1.5rem;
            border-radius: var(--radius);
            box-shadow: var(--shadow);
        }
        .search-form {
            display: flex;
            gap: 0.5rem;
        }
        .search-form input {
            flex: 1;
            padding: 0.8rem;
            border: 1px solid var(--gray-light);
            border-radius: var(--radius);
            font-size: 1rem;
        }
        .search-form button {
            background: var(--secondary);
            color: white;
            border: none;
            border-radius: var(--radius);
            padding: 0 1.5rem;
            cursor: pointer;
            transition: var(--transition);
        }
        .search-form button:hover {
            background: var(--secondary-light);
        }
        .comments-section {
            margin: 4rem 0;
        }
        .comment-form, .rating-form {
            background: white;
            padding: 2rem;
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            margin-bottom: 2rem;
        }
        .form-group {
            margin-bottom: 1.5rem;
        }
        .form-group label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 600;
        }
        .form-group input,
        .form-group textarea,
        .form-group select {
            width: 100%;
            padding: 0.8rem;
            border: 1px solid var(--gray-light);
            border-radius: var(--radius);
            font-size: 1rem;
            transition: var(--transition);
        }
        .form-group input:focus,
        .form-group textarea:focus,
        .form-group select:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(255,102,0,0.1);
        }
        .rating-stars {
            display: flex;
            gap: 0.5rem;
            font-size: 1.5rem;
            color: var(--gray-light);
            cursor: pointer;
        }
        .rating-stars i {
            transition: var(--transition);
        }
        .rating-stars i:hover,
        .rating-stars i.active {
            color: var(--warning);
        }
        .comments-list {
            margin-top: 2rem;
        }
        .comment-item {
            background: white;
            padding: 1.5rem;
            border-radius: var(--radius);
            margin-bottom: 1.5rem;
            box-shadow: var(--shadow);
        }
        .comment-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
            padding-bottom: 1rem;
            border-bottom: 1px solid var(--gray-light);
        }
        .comment-author {
            font-weight: 600;
            color: var(--secondary);
        }
        .comment-rating {
            color: var(--warning);
        }
        .comment-date {
            font-size: 0.9rem;
            color: var(--gray);
        }
        .article-image {
            width: 100%;
            max-width: 800px;
            margin: 2rem auto;
            border-radius: var(--radius);
            overflow: hidden;
            box-shadow: var(--shadow);
        }
        .article-image img {
            width: 100%;
            height: auto;
            display: block;
            transition: transform 0.5s ease;
        }
        .article-image img:hover {
            transform: scale(1.02);
        }
        .image-caption {
            text-align: center;
            font-style: italic;
            color: var(--gray);
            padding: 0.5rem;
            background: var(--gray-light);
            font-size: 0.9rem;
        }
        .content-highlight {
            background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
            border-left: 5px solid var(--secondary);
            padding: 2rem;
            margin: 2rem 0;
            border-radius: 0 var(--radius) var(--radius) 0;
        }
        .tip-box {
            background: #fff8e1;
            border-left: 5px solid var(--warning);
            padding: 1.5rem;
            margin: 2rem 0;
            border-radius: 0 var(--radius) var(--radius) 0;
        }
        .tip-box h4 {
            color: #ff8f00;
            margin-top: 0;
        }
        .internal-links {
            background: white;
            padding: 1.5rem;
            border-radius: var(--radius);
            margin: 2rem 0;
            box-shadow: var(--shadow);
        }
        .internal-links ul {
            columns: 2;
            list-style: none;
        }
        .internal-links li {
            margin-bottom: 0.8rem;
            break-inside: avoid;
        }
        .internal-links a {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            padding: 0.5rem;
            border-radius: var(--radius);
            transition: var(--transition);
        }
        .internal-links a:hover {
            background: var(--gray-light);
            text-decoration: none;
        }
        .web-links {
            background: var(--dark);
            color: white;
            padding: 3rem 0;
        }
        .web-links-container {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 2rem;
        }
        .web-link {
            background: rgba(255,255,255,0.05);
            padding: 1.5rem;
            border-radius: var(--radius);
            transition: var(--transition);
        }
        .web-link:hover {
            background: rgba(255,255,255,0.1);
            transform: translateY(-5px);
        }
        .web-link a {
            color: white;
            display: block;
            font-weight: 500;
        }
        .web-link a:hover {
            color: var(--primary);
            text-decoration: none;
        }
        footer {
            background: #1a1a1a;
            color: white;
            padding: 3rem 0 2rem;
        }
        .footer-content {
            display: grid;
            grid-template-columns: 1fr;
            gap: 2rem;
            margin-bottom: 2rem;
        }
        .footer-section h3 {
            color: white;
            margin-bottom: 1.5rem;
            font-size: 1.2rem;
        }
        .footer-links {
            list-style: none;
        }
        .footer-links li {
            margin-bottom: 0.8rem;
        }
        .footer-links a {
            color: #aaa;
            transition: var(--transition);
        }
        .footer-links a:hover {
            color: white;
            padding-left: 0.5rem;
            text-decoration: none;
        }
        .copyright {
            text-align: center;
            padding-top: 2rem;
            border-top: 1px solid #333;
            color: #888;
            font-size: 0.9rem;
        }
        @media (min-width: 768px) {
            .nav-desktop {
                display: flex;
                justify-content: space-between;
                align-items: center;
            }
            .nav-mobile {
                display: none;
            }
            .nav-list-desktop {
                display: flex;
                list-style: none;
                gap: 1.5rem;
                align-items: center;
            }
            .nav-list-desktop a {
                color: var(--dark);
                font-weight: 500;
                padding: 0.5rem 0;
                position: relative;
            }
            .nav-list-desktop a::after {
                content: '';
                position: absolute;
                bottom: 0;
                left: 0;
                width: 0;
                height: 2px;
                background: var(--primary);
                transition: width 0.3s ease;
            }
            .nav-list-desktop a:hover::after {
                width: 100%;
            }
            .nav-list-desktop a:hover {
                text-decoration: none;
                color: var(--primary);
            }
            .calculator-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .footer-content {
                grid-template-columns: repeat(3, 1fr);
            }
        }
        @media (min-width: 992px) {
            .calculator-grid {
                grid-template-columns: repeat(4, 1fr);
            }
            .internal-links ul {
                columns: 3;
            }
        }
        @media print {
            .nav-desktop,
            .nav-mobile,
            .search-box,
            .comments-section,
            .web-links,
            .footer-section,
            .calculator-widget button {
                display: none !important;
            }
            body {
                background: white;
                color: black;
            }
            .container {
                max-width: 100%;
                padding: 0;
            }
            a {
                color: black;
                text-decoration: underline;
            }
            .card, .article-header, .calculator-widget {
                box-shadow: none;
                border: 1px solid #ddd;
            }
        }