:root {
            --primary-teal: #5CBDB4;
            --primary-dark: #2d2d2d;
            --primary-gray: #D1D5DB;
            --primary-white: #FFFFFF;
            --accent-teal: #4A9B93;
            --dark-teal: #3E8B83;
            --light-gray: #F8FAFC;
            --medium-gray: #64748B;
        }

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

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
            line-height: 1.6;
            color: var(--primary-dark);
            background: var(--primary-white);
        }

        .header {
            background: linear-gradient(135deg, var(--primary-teal) 0%, var(--dark-teal) 100%);
            color: white;
            padding: 3rem 0;
            position: relative;
            overflow: hidden;
        }

        .header::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
            opacity: 0.3;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 1.5rem;
            position: relative;
            z-index: 1;
        }

        .header-content {
            text-align: center;
        }

        .header h1 {
            font-size: 2.5rem;
            font-weight: 700;
            margin-bottom: 1rem;
            letter-spacing: -0.02em;
        }

        .header .subtitle {
            font-size: 1.2rem;
            opacity: 0.9;
            max-width: 800px;
            margin: 0 auto;
            font-weight: 300;
        }

        .main-content {
            padding: 4rem 0;
        }

        section.intro-section {
            background: linear-gradient(135deg, var(--light-gray) 0%, var(--primary-gray) 100%);
            padding: 3rem 0;
            height: auto;
            margin: 0;
        }

        .intro-card {
            background: var(--primary-white);
            border-radius: 16px;
            padding: 3rem;
            box-shadow: 0 4px 6px -1px rgba(58, 58, 58, 0.1), 0 2px 4px -1px rgba(58, 58, 58, 0.06);
            border: 1px solid var(--primary-gray);
        }

        .iso-badge {
            display: inline-block;
            background: linear-gradient(135deg, var(--primary-teal) 0%, var(--accent-teal) 100%);
            color: white;
            padding: 0.5rem 1rem;
            border-radius: 20px;
            font-size: 0.875rem;
            font-weight: 600;
            margin-bottom: 1.5rem;
        }

        .video-section {
            background: var(--primary-white);
            border-radius: 16px;
            padding: 2rem;
            margin: 2rem 0;
            box-shadow: 0 1px 3px 0 rgba(58, 58, 58, 0.1);
            border: 1px solid var(--primary-gray);
        }

        .video-container {
            position: relative;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 10px 25px -5px rgba(58, 58, 58, 0.1);
        }

        video {
            width: 100%;
            height: auto;
            display: block;
        }

        .section {
            margin: 3rem 0;
        }

        .section-title {
            font-size: 1.875rem;
            font-weight: 700;
            color: var(--primary-dark);
            margin-bottom: 1.5rem;
            padding-bottom: 0.75rem;
            border-bottom: 3px solid var(--primary-teal);
            display: inline-block;
        }

        .subsection-title {
            font-size: 1.5rem;
            font-weight: 600;
            color: var(--primary-dark);
            margin: 2.5rem 0 1.5rem 0;
            display: flex;
            align-items: center;
            gap: 0.75rem;
        }

        .icon {
            font-size: 1.75rem;
        }

        .content-card {
            background: var(--primary-white);
            border-radius: 12px;
            padding: 2rem;
            margin: 1.5rem 0;
            border: 1px solid var(--primary-gray);
            box-shadow: 0 1px 3px 0 rgba(58, 58, 58, 0.1);
        }

        .requirements-list {
            list-style: none;
            padding: 0;
        }

        .requirements-list li {
            background: var(--light-gray);
            margin: 0.75rem 0;
            padding: 1rem 1.5rem;
            border-radius: 8px;
            border-left: 4px solid var(--primary-teal);
            position: relative;
            transition: all 0.2s ease;
        }

        .requirements-list li:hover {
            transform: translateX(4px);
            box-shadow: 0 2px 8px rgba(92, 189, 180, 0.15);
        }

        .requirements-list li::before {
            content: '✓';
            position: absolute;
            left: -12px;
            top: 50%;
            transform: translateY(-50%);
            background: var(--primary-teal);
            color: white;
            width: 24px;
            height: 24px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 12px;
            font-weight: bold;
        }

        .docs-section {
            background: linear-gradient(135deg, rgba(92, 189, 180, 0.1) 0%, rgba(74, 155, 147, 0.15) 100%);
            border-radius: 12px;
            padding: 2rem;
            margin: 2rem 0;
            border: 1px solid var(--primary-teal);
        }

        .docs-title {
            font-size: 1.25rem;
            font-weight: 600;
            color: var(--dark-teal);
            margin-bottom: 1rem;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .docs-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 0.75rem;
            margin-top: 1rem;
        }

        .doc-link {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            background: var(--primary-white);
            padding: 0.875rem 1rem;
            border-radius: 8px;
            text-decoration: none;
            color: var(--dark-teal);
            border: 1px solid var(--primary-gray);
            transition: all 0.2s ease;
            font-weight: 500;
        }

        .doc-link:hover {
            background: var(--light-gray);
            transform: translateY(-1px);
            box-shadow: 0 4px 8px rgba(58, 58, 58, 0.1);
            text-decoration: none;
            border-color: var(--primary-teal);
        }

        .doc-icon {
            font-size: 1.25rem;
            color: #dc2626;
        }

        .concept-card {
            background: linear-gradient(135deg, rgba(92, 189, 180, 0.1) 0%, rgba(92, 189, 180, 0.2) 100%);
            border-radius: 16px;
            padding: 2.5rem;
            margin: 2rem 0;
            border: 1px solid var(--primary-teal);
            position: relative;
            overflow: hidden;
        }

        .concept-card::before {
            content: '';
            position: absolute;
            top: -50%;
            right: -50%;
            width: 100%;
            height: 200%;
            background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="2" fill="rgba(92,189,180,0.1)"/></svg>');
            animation: float 20s ease-in-out infinite;
        }

        @keyframes float {
            0%, 100% { transform: translateY(0px) rotate(0deg); }
            50% { transform: translateY(-20px) rotate(180deg); }
        }

        .concept-quote {
            font-size: 1.5rem;
            font-style: italic;
            color: var(--dark-teal);
            text-align: center;
            margin-bottom: 1.5rem;
            font-weight: 500;
            position: relative;
            z-index: 1;
        }

        .concept-list {
            list-style: none;
            padding: 0;
            position: relative;
            z-index: 1;
        }

        .concept-list li {
            background: rgba(255, 255, 255, 0.8);
            margin: 0.75rem 0;
            padding: 1rem;
            border-radius: 8px;
            border-left: 4px solid var(--primary-teal);
        }

        .alert-section {
            background: linear-gradient(135deg, rgba(58, 58, 58, 0.05) 0%, rgba(58, 58, 58, 0.1) 100%);
            border-radius: 12px;
            padding: 2rem;
            margin: 2rem 0;
            border: 1px solid var(--primary-dark);
        }

        .alert-content {
            background: var(--primary-white);
            padding: 1.5rem;
            border-radius: 8px;
            font-weight: 600;
            color: var(--primary-dark);
            text-align: center;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
        }

        .closing-quote {
            background: linear-gradient(135deg, rgba(92, 189, 180, 0.1) 0%, rgba(74, 155, 147, 0.15) 100%);
            border-radius: 16px;
            padding: 3rem;
            margin: 3rem 0;
            border: 1px solid var(--primary-teal);
            text-align: center;
        }

        .closing-text {
            font-size: 1.375rem;
            font-style: italic;
            color: var(--dark-teal);
            font-weight: 500;
            line-height: 1.7;
        }

        .footer-item {
            background: var(--primary-dark);
            color: var(--primary-white);
            padding: 2rem 0;
            text-align: center;
            
        }

        .footer-item-content {
            font-size: 0.875rem;
            opacity: 0.8;
        }

        /* Кнопки и интерактивные элементы */
        .btn-primary {
            background: linear-gradient(135deg, var(--primary-teal) 0%, var(--accent-teal) 100%);
            color: white;
            border: none;
            padding: 0.75rem 1.5rem;
            border-radius: 8px;
            font-weight: 600;
            text-decoration: none;
            display: inline-block;
            transition: all 0.2s ease;
        }

        .btn-primary:hover {
            transform: translateY(-1px);
            box-shadow: 0 4px 8px rgba(92, 189, 180, 0.3);
            text-decoration: none;
            color: white;
        }

        /* Адаптивность */
        @media (max-width: 768px) {
            .container {
                padding: 0 1rem;
            }

            .header h1 {
                font-size: 2rem;
            }

            .header .subtitle {
                font-size: 1rem;
            }

            .intro-card,
            .concept-card {
                padding: 1.5rem;
            }

            .section-title {
                font-size: 1.5rem;
            }

            .subsection-title {
                font-size: 1.25rem;
            }

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

            .concept-quote,
            .closing-text {
                font-size: 1.125rem;
            }
        }

        /* Дополнительные элементы в фирменном стиле */
        .teal-accent {
            color: var(--primary-teal);
        }

        .highlight-box {
            background: rgba(92, 189, 180, 0.1);
            border: 1px solid var(--primary-teal);
            border-radius: 8px;
            padding: 1rem;
            margin: 1rem 0;
        }

        .status-indicator {
            width: 12px;
            height: 12px;
            background: var(--primary-teal);
            border-radius: 50%;
            display: inline-block;
            margin-right: 0.5rem;
        }