:root { 
    --primary-color: #4F46E5; 
    --bg-color: #F3F4F6; 
    --text-color: #1F2937; 
    --card-bg: #FFFFFF;
}
* { box-sizing: border-box; }
body { 
    font-family: system-ui, -apple-system, sans-serif; 
    background: var(--bg-color); 
    color: var(--text-color); 
    margin: 0; 
    line-height: 1.6;
}
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
header { 
    background: var(--card-bg); 
    padding: 15px 0; 
    box-shadow: 0 1px 3px rgba(0,0,0,0.1); 
    position: sticky; 
    top: 0; 
    z-index: 50; 
}
.header-container { 
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
}
.nav-links { 
    display: flex; 
    align-items: center; 
    gap: 15px; 
}
.nav-links a { 
    text-decoration: none; 
    color: var(--text-color); 
    font-weight: 500; 
    transition: color 0.2s; 
    white-space: nowrap; 
}
.nav-links a:hover { color: var(--primary-color); }

.card { 
    background: var(--card-bg); 
    padding: 24px; 
    border-radius: 12px; 
    box-shadow: 0 4px 6px rgba(0,0,0,0.05); 
    margin-top: 20px;
}
.btn {
    background: var(--primary-color); color: white; padding: 10px 20px;
    border: none; border-radius: 8px; cursor: pointer; text-decoration: none; 
    text-align: center; font-weight: 500; transition: opacity 0.2s; display: inline-block;
}
.btn:hover { opacity: 0.9; }

/* === МОБИЛЬНОЕ МЕНЮ (SIDEBAR) === */
.menu-toggle { 
    display: none; 
    font-size: 1.8rem; 
    cursor: pointer; 
    background: none; 
    border: none; 
    color: var(--text-color); 
    padding: 0; 
}
.sidebar-overlay { 
    position: fixed; top: 0; left: 0; width: 100%; height: 100%; 
    background: rgba(0,0,0,0.5); z-index: 99; opacity: 0; 
    visibility: hidden; transition: 0.3s; 
}
.sidebar-overlay.active { opacity: 1; visibility: visible; }
.sidebar { 
    position: fixed; top: 0; right: -300px; width: 280px; height: 100%; 
    background: var(--card-bg); box-shadow: -5px 0 15px rgba(0,0,0,0.1); 
    z-index: 100; transition: right 0.3s ease; display: flex; 
    flex-direction: column; padding: 20px; gap: 15px; overflow-y: auto; 
}
.sidebar.active { right: 0; }
.sidebar-header { 
    display: flex; justify-content: space-between; align-items: center; 
    border-bottom: 1px solid #e5e7eb; padding-bottom: 15px; margin-bottom: 10px; 
}
.close-btn { 
    background: none; border: none; font-size: 2.5rem; cursor: pointer; 
    color: #9ca3af; line-height: 0.5; padding: 0; 
}
.sidebar a { 
    text-decoration: none; color: var(--text-color); font-size: 1.1rem; 
    font-weight: 500; border-bottom: 1px solid #f3f4f6; padding-bottom: 10px; 
}

/* Адаптивность: скрываем десктопное меню на планшетах и телефонах */
@media (max-width: 900px) {
    .nav-links { display: none; }
    .menu-toggle { display: block; }
}