.topic-page {
            background-color: #0b0f14;
            color: #ffffff;
            min-height: 100vh;
            padding: 40px 20px 80px 20px;
        }
        .topic-container {
            max-width: 1000px;
            margin: 0 auto;
        }
        .back-link {
            color: #00d2ff;
            text-decoration: none;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            font-size: 14px;
            margin-bottom: 30px;
            transition: opacity 0.2s;
        }
        .back-link:hover { color: #0066ff; text-decoration: none; }
        
        .topic-header {
            border-bottom: 1px solid rgba(255, 255, 255, 0.05);
            padding-bottom: 20px;
            margin-bottom: 40px;
        }
        .topic-breadcrumbs { font-size: 13px; color: #718096; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 5px; }
        .topic-title { font-size: 36px; font-weight: 800; color: #ffffff; margin: 0; }

        /* Стилі для розділів (Теорія, Відео, Тести) */
        .section-card {
            background: #121820;
            border: 1px solid rgba(255, 255, 255, 0.03);
            border-radius: 20px;
            padding: 35px;
            margin-bottom: 35px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
        }
        .section-card-title {
            font-size: 22px;
            font-weight: 700;
            color: #ffffff;
            margin-top: 0;
            margin-bottom: 20px;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .section-card-title span {
            color: #00d2ff;
        }

        /* Блок теорії */
        .theory-content {
            color: #cbd5e0;
            font-size: 16px;
            line-height: 1.7;
        }

        /* Блок відео */
        .video-wrapper {
            position: relative;
            padding-bottom: 56.25%; /* Пропорції 16:9 */
            height: 0;
            border-radius: 12px;
            overflow: hidden;
            border: 1px solid rgba(0, 210, 255, 0.1);
        }
        .video-wrapper iframe {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
        }

        /* Блок списку тестів */
        .tests-list {
            display: flex;
            flex-direction: column;
            gap: 15px;
        }
        .test-item {
            background: rgba(255, 255, 255, 0.02);
            border: 1px solid rgba(0, 210, 255, 0.08);
            border-radius: 12px;
            padding: 20px 25px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: all 0.3s ease;
        }
        .test-item:hover {
            border-color: #00d2ff;
            background: rgba(0, 210, 255, 0.02);
            transform: translateX(5px);
        }
        .test-info h4 {
            font-size: 16px;
            font-weight: 600;
            color: #ffffff;
            margin: 0 0 5px 0;
        }
        .test-info p {
            font-size: 13px;
            color: #718096;
            margin: 0;
        }
        .start-test-btn {
            background: linear-gradient(135deg, #00d2ff 0%, #0066ff 100%);
            color: #ffffff !important;
            padding: 10px 24px;
            border-radius: 8px;
            font-weight: 700;
            font-size: 14px;
            text-decoration: none;
            box-shadow: 0 4px 12px rgba(0, 210, 255, 0.15);
            transition: all 0.2s;
        }
        .start-test-btn:hover {
            transform: translateY(-1px);
            box-shadow: 0 6px 18px rgba(0, 210, 255, 0.3);
            text-decoration: none;
        }

        /* Стилі вашої шапки */
        header { padding: 30px 40px; display: flex; justify-content: space-between; align-items: center; max-width: 1200px; width: 100%; margin: 0 auto; position: relative; z-index: 100; }
        .logo-text { font-size: 24px; font-weight: 800; letter-spacing: 2px; background: linear-gradient(135deg, #00d2ff 0%, #0066ff 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; text-shadow: 0 0 20px rgba(0, 210, 255, 0.3); }
        nav { display: flex; align-items: center; justify-content: flex-end; width: auto; }
        .nav-links { display: flex; list-style: none; gap: 30px; margin-right: 35px; padding: 0; margin: 0; align-items: center; }
        .nav-links a { color: #a0aec0; text-decoration: none; font-weight: 500; font-size: 16px; transition: color 0.3s ease; }
        .nav-links a:hover { color: #00d2ff; }
        .contact-btn { background: transparent; border: 2px solid #00d2ff; color: #00d2ff; padding: 8px 22px; border-radius: 20px; font-weight: 600; font-size: 15px; transition: all 0.3s ease; text-decoration: none; }
        .contact-btn:hover { background: #00d2ff; color: #121820; box-shadow: 0 0 15px rgba(0, 210, 255, 0.5); }