/* ===== تنظیمات پایه و ریست ===== */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', 'Tahoma', 'Vazir', system-ui, sans-serif;
        }
        body {
            background: #0b1a2a;
            color: #f0f4fa;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        @font-face {
            font-family: titr;
            src: url(fonts/pixelboy-BTitrBold.eot);
            src: url(fonts/pixelboy-BTitrBold.ttf);
            src: url(fonts/pixelboy-BTitrBold.woff);
        }

        @font-face {
            font-family: yekan;
            src: url(fonts/yekan-font/Yekan.eot);
            src: url(fonts/yekan-font/Yekan.ttf);
            src: url(fonts/yekan-font/Yekan.woff);
        }

        h1, h2, h3, h4, h5, h6 {
            font-family: titr;
        }

        p, span {
            font-family: yekan;
        }

        a {
            text-decoration: none;
            color: inherit;
        }
        /* ===== چیدمان اصلی (دو ستونه) ===== */
        .app-wrapper {
            display: flex;
            flex: 1;
            min-height: 80vh;
        }
        /* ===== بخش اصلی (سمت چپ) ===== */
        .content-area {
            flex: 1;
            position: relative;
            overflow-y: auto;
            padding: 1.5rem 2rem 1.5rem 1.5rem;
            display: flex;
            flex-direction: column;
        }
        /* ----- پس‌زمینه اسلایدشو ----- */
        .bg-slideshow {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: 0;
            overflow: hidden;
        }
        .bg-slideshow .slide {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-size: cover;
            background-position: center 30%;
            opacity: 0;
            transition: opacity 1.8s ease-in-out;
            filter: brightness(0.45) saturate(0.9);
        }
        .bg-slideshow .slide.active {
            opacity: 1;
        }
        /* ----- لایه شفاف روی محتوا برای خوانایی بهتر ----- */
        .content-overlay {
            position: relative;
            z-index: 2;
            background: rgba(10, 20, 35, 0.65);
            backdrop-filter: transparent;
            -webkit-backdrop-filter: blur(4px);
            border-radius: 32px;
            padding: 2rem 2.5rem;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.7);
            border: 1px solid rgba(255, 215, 100, 0.12);
            flex: 1;
            text-align: center;
        }
        /* ===== هدر بزرگ ===== */
        .main-header {
            text-align: center;
            padding: 1.2rem 0 0.8rem 0;
            border-bottom: 3px solid #e8a838;
            margin-bottom: 2rem;
        }
        .main-header h1 {
            font-size: 2.8rem;
            font-weight: 800;
            color: #f5d99b;
            letter-spacing: 1px;
            text-shadow: 0 4px 12px rgba(0,0,0,0.5);
        }
        .main-header h1 i {
            color: #e8a838;
            margin-left: 14px;
        }
        .main-header p {
            font-size: 1.1rem;
            color: #c9dcee;
            margin-top: 6px;
            letter-spacing: 0.5px;
        }
        /* ===== نوار کناری (سمت راست) ===== */
        .sidebar {
            width: 270px;
            min-width: 200px;
            background: linear-gradient(160deg, #0f253a, #071624);
            border-right: 3px solid #e8a838;
            padding: 1.2rem 0.6rem 2rem 0.6rem;
            display: flex;
            flex-direction: column;
            height: 100vh;
            position: sticky;
            top: 0;
            overflow-y: auto;
            z-index: 10;
            box-shadow: 8px 0 25px rgba(0, 0, 0, 0.6);
            scrollbar-width: thin;
            scrollbar-color: #e8a838 #1a2f44;
        }
        .sidebar::-webkit-scrollbar {
            width: 5px;
        }
        .sidebar::-webkit-scrollbar-track {
            background: #1a2f44;
        }
        .sidebar::-webkit-scrollbar-thumb {
            background: #e8a838;
            border-radius: 12px;
        }
        .sidebar-title {
            font-size: 1.3rem;
            font-weight: 700;
            color: #f5e7c8;
            text-align: center;
            padding-bottom: 0.8rem;
            border-bottom: 2px solid #e8a838;
            margin-bottom: 1.5rem;
            font-family: yekan;

        }
        .sidebar-title i {
            color: #e8a838;
            margin-left: 10px;
        }
        .lesson-list {
            list-style: none;
            padding: 0;
            margin: 0;
            flex: 1;
            
        }
        .lesson-list li {
            margin-bottom: 0.3rem;
        }
        .lesson-list a {
            display: flex;
            align-items: center;
            gap: 10px;
            color: #d4e0ed;
            padding: 0.6rem 1rem;
            border-radius: 40px 8px 8px 40px;
            font-size: 0.95rem;
            font-weight: 500;
            transition: all 0.2s ease;
            border-right: 3px solid transparent;
            background: transparent;
            font-family: yekan;

        }
        .lesson-list a i {
            width: 1.6rem;
            color: #b9c9db;
            font-size: 1rem;
            text-align: center;
            transition: 0.2s;
        }
        .lesson-list a:hover {
            background: rgba(232, 168, 56, 0.12);
            border-right: 3px solid #e8a838;
            color: #fff7e6;
            padding-right: 1.4rem;
        }
        .lesson-list a.active {
            background: rgba(232, 168, 56, 0.18);
            border-right: 4px solid #e8a838;
            color: #ffe6b0;
            font-weight: 600;
        }
        .lesson-list a.active i {
            color: #e8a838;
        }
        .lesson-badge {
            background: #e8a838;
            color: #0b1a2a;
            font-size: 0.6rem;
            font-weight: 800;
            padding: 0.1rem 0.6rem;
            border-radius: 40px;
            margin-right: auto;
        }
        /* ===== محتوای هر درس (در صفحه اصلی فقط عنوان و توضیح کوتاه) ===== */
        .lesson-preview {
            display: none;
            animation: fadeSlide 0.4s ease;
        }
        .lesson-preview.active {
            display: block;
            height: auto;
        }    
        .startbtn {
            padding: 7px 20px;
            background-color: #f5d99b;
            font-family: yekan;
            font-size: 1.5 rem;
        }
        @keyframes fadeSlide {
            0% { opacity: 0.3; transform: translateY(10px); }
            100% { opacity: 1; transform: translateY(0); }
        }
        .lesson-preview h2 {
            font-size: 2.2rem;
            font-weight: 700;
            color: #f5d99b;
            border-bottom: 3px solid #e8a838;
            padding-bottom: 0.4rem;
            margin-bottom: 1.8rem;
        }
        .lesson-preview h2 i {
            margin-left: 12px;
            color: #e8a838;
        }
        .lesson-preview p {
            font-size: 1.05rem;
            line-height: 1.9;
            color: #ecf3fc;
        }
        .highlight-box {
            background: rgba(232, 168, 56, 0.10);
            border-right: 6px solid #e8a838;
            padding: 1rem 1.8rem;
            border-radius: 16px 4px 4px 16px;
            margin: 1.2rem 0;
            backdrop-filter: blur(2px);
        }
        .highlight-box strong {
            color: #f5d99b;
        }
        /* ===== فوتر ===== */
        .app-footer {
            background: #0b1a2a;
            border-top: 2px solid #e8a83840;
            padding: 1.2rem 2rem;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            gap: 1rem;
            color: #b8c9dd;
            font-size: 0.9rem;
            margin-top: auto;
            z-index: 5;
            position: relative;
        }
        .footer-logo {
            font-size: 1.3rem;
            font-weight: 700;
            color: #f5d99b;
        }
        .footer-logo img {
            color: #e8a838;
            margin-left: 8px;
            width: 100px;
            height: auto;
        }
        .footer-contact i {
            margin-left: 8px;
            color: #e8a838;
        }
        .footer-contact span {
            margin-left: 20px;
        }
        .footer-social a {
            color: #d4e0ed;
            margin: 0 8px;
            font-size: 1.5rem;
            transition: 0.2s;
            display: inline-block;
        }
        .footer-social a:hover {
            color: #e8a838;
            transform: scale(1.1);
        }
        /* ===== واکنش‌گرایی ===== */
        @media (max-width: 820px) {
            .app-wrapper {
                flex-direction: column-reverse;
            }
            .sidebar {
                width: 100%;
                height: auto;
                max-height: 260px;
                position: relative;
                border-right: none;
                border-bottom: 3px solid #e8a838;
                padding: 0.6rem 0.3rem;
                flex-shrink: 0;
                overflow-y: auto;
                box-shadow: 0 8px 20px rgba(0,0,0,0.5);
            }
            .sidebar-title {
                font-size: 1rem;
                margin-bottom: 0.3rem;
                padding-bottom: 0.3rem;
            }
            .lesson-list {
                display: flex;
                flex-wrap: wrap;
                gap: 0.2rem;
                justify-content: center;
            }
            .lesson-list li {
                margin: 0;
            }
            .lesson-list a {
                padding: 0.2rem 0.7rem;
                border-radius: 30px;
                font-size: 0.75rem;
                border-right: none;
                border: 1px solid transparent;
                background: rgba(255,255,255,0.03);
            }
            .lesson-list a:hover, .lesson-list a.active {
                border-right: none;
                border-color: #e8a838;
                background: rgba(232,168,56,0.12);
                padding-right: 0.7rem;
            }
            .content-area {
                padding: 0.8rem;
            }
            .content-overlay {
                padding: 1.2rem 1rem;
                border-radius: 20px;
            }
            .main-header h1 {
                font-size: 1.8rem;
            }
            .app-footer {
                flex-direction: column;
                text-align: center;
                padding: 0.8rem;
            }
            .footer-contact span {
                display: inline-block;
                margin: 0 6px;
            }
        }
        @media (max-width: 480px) {
            .main-header h1 {
                font-size: 1.4rem;
            }
            .content-overlay {
                padding: 0.8rem 0.6rem;
            }
            .sidebar {
                max-height: 200px;
            }
            .lesson-list a {
                font-size: 0.65rem;
                padding: 0.1rem 0.5rem;
            }
        }