:root {
            --primary-color: #ff6b35;
            --secondary-color: #1e3a8a;
            --accent-color: #f59e0b;
            --text-dark: #1f2937;
            --text-light: #6b7280;
            --bg-light: #f8fafc;
        }
        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            line-height: 1.7;
            color: var(--text-dark);
            background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
        }
        .hero-section {
            background: linear-gradient(rgba(30, 58, 138, 0.9), rgba(245, 158, 11, 0.8)), url('https://via.placeholder.com/1200x600');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 100px 0;
            border-radius: 0 0 30px 30px;
            margin-bottom: 50px;
        }
        .section-title {
            color: var(--secondary-color);
            border-left: 5px solid var(--primary-color);
            padding-left: 15px;
            margin: 40px 0 25px;
            font-weight: 700;
        }
        .content-card {
            background: white;
            border-radius: 15px;
            padding: 30px;
            margin-bottom: 30px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border: none;
        }
        .content-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 40px rgba(0,0,0,0.15);
        }
        .highlight-text {
            background: linear-gradient(120deg, var(--accent-color) 0%, var(--accent-color) 100%);
            background-repeat: no-repeat;
            background-size: 100% 0.3em;
            background-position: 0 88%;
            font-weight: 600;
            padding: 0 2px;
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 15px;
        }
        .img-fluid {
            border-radius: 12px;
            box-shadow: 0 8px 25px rgba(0,0,0,0.15);
            transition: transform 0.3s ease;
        }
        .img-fluid:hover {
            transform: scale(1.02);
        }
        .nav-pills .nav-link.active {
            background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
            border: none;
            font-weight: 600;
        }
        .nav-pills .nav-link {
            color: var(--text-dark);
            font-weight: 500;
            margin: 5px 0;
            border-radius: 8px;
        }
        footer {
            background: var(--secondary-color);
            color: white;
            padding: 40px 0 20px;
            margin-top: 60px;
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 60px 0;
                border-radius: 0 0 20px 20px;
            }
            .content-card {
                padding: 20px;
            }
        }
        .tank-stats {
            background: var(--bg-light);
            border-radius: 10px;
            padding: 20px;
            margin: 20px 0;
        }
        .stat-bar {
            height: 8px;
            background: #e5e7eb;
            border-radius: 4px;
            margin: 10px 0;
            overflow: hidden;
        }
        .stat-fill {
            height: 100%;
            border-radius: 4px;
            background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
        }
        .key-point {
            background: linear-gradient(135deg, #fef3c7, #fed7aa);
            border-left: 4px solid var(--accent-color);
            padding: 15px;
            margin: 15px 0;
            border-radius: 0 8px 8px 0;
        }