/* Base / Desktop Styles */
body {
    font-family: Arial, Helvetica, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f5f5f5;
    color: #333;
}
.page-wrapper {
    max-width: 1200px;
    margin: 0 auto;
    background: #fff;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}
header {
    display: flex;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid #ddd;
}
.logo { margin-right: 20px; }
.header-text h1 { font-size: 1.3rem; color: #666; margin: 0 0 5px 0; font-weight: normal; }
.header-text h2 { font-size: 1.3rem; color: #880000; margin: 0; font-weight: normal; }

/* Main Layout Split */
.main-container {
    display: flex;
    flex: 1;
}

/* Desktop Sidebar Navigation */
aside {
    width: 220px;
    padding: 20px;
    background: #fff;
    border-right: 1px solid #eee;
}
aside p { margin: 0 0 15px 0; font-size: 14px; line-height: 1.4; }
aside a { color: #0066cc; text-decoration: none; }
aside a:hover { text-decoration: underline; }
.tab-btn { display: block; margin-bottom: 8px; }

/* Mobile Menu Header (White Theme) */
.mobile-nav-bar {
    display: none;
    background: #ffffff;
    color: #333333;
    padding: 10px 15px;
    justify-content: space-between;
    align-items: center;
    position: relative;
    border-bottom: 1px solid #ddd;
}
.menu-toggle {
    display: flex;
    align-items: center;
    cursor: pointer;
    user-select: none;
    font-weight: bold;
}
.menu-toggle img { 
    margin-right: 8px; 
}
.mobile-menu-list {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: #f9f9f9;
    margin: 0;
    padding: 0;
    list-style: none;
    z-index: 1000;
    box-shadow: 0px 4px 6px rgba(0,0,0,0.1);
}
.mobile-menu-list li a {
    display: block;
    padding: 12px 20px;
    color: #333333;
    text-decoration: none;
    border-bottom: 1px solid #eee;
}
.mobile-menu-list li a:hover {
    background: #eaeaea;
}

#menu-checkbox { display: none; }
#menu-checkbox:checked ~ .mobile-menu-list { display: block; }

/* Content Area */
main {
    flex: 1;
    padding: 20px;
}
.intro-heading { color: #408080; font-weight: bold; margin-bottom: 15px; }
.content-body p { line-height: 1.5; margin-bottom: 15px; text-align: justify; }
.product-img-box { text-align: center; margin: 25px 0; }
.product-img-box img { max-width: 100%; height: auto; }

footer {
    margin-top: auto;
    border-top: 1px solid #eee;
    padding-top: 15px;
    font-size: 13px;
}

/* --- Responsive Breakpoint --- */
@media (max-width: 768px) {
    header { flex-direction: column; text-align: center; }
    .logo { margin-right: 0; margin-bottom: 10px; }
    .header-text h1, .header-text h2 { font-size: 1.1rem; }
    
    .main-container { flex-direction: column; }
    aside { display: none; }
    
    .mobile-nav-bar { display: flex; }
    main { padding: 15px; }
}