/* Basic styles for the new header and promo block */
        body {
            font-family: 'Roboto', sans-serif;
            line-height: 1.6;
            margin: 0;
            background-color: #f4f4f9;
            color: #333;
        }
        .container {
            max-width: 1100px;
            margin: 0 auto;
            padding: 20px;
            background-color: #fff;
            box-shadow: 0 0 10px rgba(0,0,0,0.05);
        }
        .guide-header {
            background-color: #2c3e50;
            color: #ecf0f1;
            padding: 1rem 0;
            margin-bottom: 2rem;
        }
        .header-top {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 1rem;
            padding: 1rem 0;
            margin-bottom: 1rem;
        }
        .header-logo {
            width: 60px;
            height: 60px;
            border-radius: 8px;
            margin-right: 0.5rem;
        }
        .discount-wrap {
            display: flex;
            align-items: center;
            gap: 1rem;
        }
        .discount {
            font-size: 1.2rem;
            color: #ffd700;
            text-decoration: none;
            animation: glow 1.5s ease-in-out infinite alternate;
            display: inline-block;
        }
        .discount:hover {
            color: #fff7cc;
        }
        .buy-course-btn {
            background-color: #00b7c5;
            color: white;
            padding: 0.7rem 1.5rem;
            border-radius: 15px;
            text-decoration: none;
            font-weight: bold;
            position: relative;
            overflow: hidden;
            border: none;
            z-index: 1;
        }
        .buy-course-btn {
    position: relative; /* нужно для ::before */
    overflow: hidden; /* обрезаем вылезающий цвет */
    transition: transform 0.35s cubic-bezier(0.25, 1, 0.3, 1),
                box-shadow 0.35s cubic-bezier(0.25, 1, 0.3, 1);
}

.buy-course-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background-color: #009aa6;
    transition: left 0.5s ease; /* только движение */
    z-index: -1;
}

.buy-course-btn:hover::before {
    left: 0;
}

.buy-course-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}


        .guide-header nav {
            display: block;
            text-align: center;
        }
        .guide-header nav ul {
            list-style: none;
            padding: 0;
            margin: 0;
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
        }
        .guide-header nav ul li {
            margin: 0 0.5rem;
        }
        .guide-header nav ul li a {
            color: #ecf0f1;
            text-decoration: none;
            padding: 0.5rem 1rem;
            display: block;
            border-radius: 5px;
            transition: background-color 0.3s;
        }
        .guide-header nav ul li a:hover,
        .guide-header nav ul li a.active {
            background-color: #34495e;
        }
        @keyframes glow {
            from {
                text-shadow: 0 0 5px #fff, 0 0 10px #fff, 0 0 15px #ffd700;
            }
            to {
                text-shadow: 0 0 10px #fff, 0 0 20px #fff, 0 0 30px #ffd700;
            }
        }
        
        .guide-header nav ul {
            list-style: none;
            padding: 0;
            margin: 0;
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
        }
        .guide-header nav ul li a {
            color: #ecf0f1;
            text-decoration: none;
            padding: 0.5rem 1rem;
            display: block;
            border-radius: 5px;
            transition: background-color 0.3s;
        }
        .guide-header nav ul li a:hover, .guide-header nav ul li a.active {
            background-color: #34495e;
        }
        .course-promo {
            margin-top: 3rem;
            text-align: center;
            background: linear-gradient(145deg, #ffffff 0%, #f0f7f8 100%);
            padding: 2.5rem;
            border-radius: 16px;
            box-shadow: 0 10px 30px rgba(0, 183, 197, 0.1);
            border: 1px solid rgba(0, 183, 197, 0.1);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .course-promo:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 40px rgba(0, 183, 197, 0.15);
        }
        .course-promo h2 {
            margin: 0 0 1.5rem 0;
            color: #2c3e50;
            font-size: 2rem;
            font-weight: 700;
            background: linear-gradient(90deg, #2c3e50, #00b7c5);
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
            /* text-fill-color: transparent; */
            display: inline-block;
        }
        .course-promo .promo-button {
            display: inline-block;
            background-color: #00b7c5;
            color: #fff;
            padding: 12px 25px;
            text-decoration: none;
            font-weight: bold;
            border-radius: 15px;
            margin-top: 1rem;
            position: relative;
            overflow: hidden;
            z-index: 1;
        }
        .course-promo .promo-button::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background-color: #009aa6;
            transition: all 0.5s ease;
            z-index: -1;
        }
        .course-promo .promo-button:hover::before {
            left: 0;
        }
        /* --- Content Styles --- */
        .content h1, .content h2, .content h3, .content h4 {
            color: #2c3e50;
        }
        .content a {
            color: #2980b9;
        }
        .content pre {
            background-color: #2d2d2d;
            color: #f1f1f1;
            padding: 15px;
            border-radius: 5px;
            overflow-x: auto;
        }
        .content code {
            font-family: 'Courier New', Courier, monospace;
        }
        /* Default for all images in content */
        .content img {
            max-width: 100%;
            height: auto;
            vertical-align: middle; /* Good default for inline */
            margin: 0 0.2em;
        }
        /* For images in centered paragraphs, make them blocks for centering */
        .content p[style*="text-align:center"] img {
           display: block;
        }

        /* Footer Styles */
        .footer {
            background-color: #2c3e50;
            color: #ecf0f1;
            text-align: center;
            padding: 2rem 0;
            margin-top: 3rem;
        }
        .footer p {
            margin: 0;
            font-size: 1.1rem;
        }
        .footer .heart {
            color: #e74c3c;
            animation: heartbeat 1.5s infinite;
        }
        @keyframes heartbeat {
            0% { transform: scale(1); }
            50% { transform: scale(1.1); }
            100% { transform: scale(1); }
        }