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

body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* Боковое меню */
.sidebar {
    position: fixed;
    left: -300px;
    top: 0;
    width: 300px;
    height: 100vh;
    background: linear-gradient(45deg, #2c3e50, #34495e);
    color: white;
    transition: left 0.3s ease;
    z-index: 1000;
    box-shadow: 2px 0 10px rgba(0,0,0,0.3);
}

.sidebar.open {
    left: 0;
}

.sidebar-header {
    padding: 20px;
    background: #1a252f;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.sidebar-header h3 {
    margin: 0;
    color: #ecf0f1;
}

.close-btn {
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 5px;
}

.close-btn:hover {
    color: #e74c3c;
}

.sidebar-menu {
    list-style: none;
    padding: 20px 0;
}

.sidebar-menu li {
    margin: 0;
}

.sidebar-menu a {
    display: block;
    padding: 15px 30px;
    color: #bdc3c7;
    text-decoration: none;
    transition: all 0.3s ease;
    font-size: 1.1rem;
}

.sidebar-menu a:hover {
    background: #34495e;
    color: #ecf0f1;
    padding-left: 40px;
}

.sidebar-menu i {
    margin-right: 10px;
    width: 20px;
    text-align: center;
}

/* Основной контент */
.main-content {
    transition: margin-left 0.3s ease;
    min-height: 100vh;
}

.menu-btn {
    position: fixed;
    top: 20px;
    left: 20px;
    background: #2c3e50;
    color: white;
    border: none;
    padding: 15px;
    border-radius: 50%;
    cursor: pointer;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
}

.menu-btn:hover {
    background: #34495e;
    transform: scale(1.1);
}

.container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.main-content-center {
    text-align: center;
    background: white;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    max-width: 500px;
    width: 100%;
}

.main-content-center h1 {
    color: #2c3e50;
    margin-bottom: 20px;
    font-size: 2.5rem;
}

.main-content-center p {
    color: #7f8c8d;
    margin-bottom: 30px;
    font-size: 1.2rem;
}

.main-button {
    background: linear-gradient(45deg, #3498db, #2980b9);
    color: white;
    border: none;
    padding: 15px 40px;
    font-size: 1.1rem;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3);
}

.main-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(52, 152, 219, 0.4);
    background: linear-gradient(45deg, #2980b9, #3498db);
}

/* Overlay */
.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
}

.overlay.active {
    opacity: 1;
    visibility: visible;
}

/* Адаптивность */
@media (max-width: 768px) {
    .sidebar {
        width: 250px;
        left: -250px;
    }

    .main-content-center {
        margin: 20px;
        padding: 30px 20px;
    }

    .main-content-center h1 {
        font-size: 2rem;
    }
}