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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    height: 100vh;
    background: linear-gradient(135deg, #f5f7fa, #c3cfe2);
}

.sidebar {
    width: 25%;
    background: linear-gradient(135deg, #2c3e50, #4ca1af);
    color: white;
    padding: 20px;
    overflow-y: auto;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.2);
}

.sidebar h2 {
    text-align: center;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #16a085;
    font-size: 1.8rem;
    color: #ecf0f1;
}

.sidebar ul {
    list-style: none;
}

.sidebar ul li {
    margin: 12px 0;
    padding: 12px;
    background: #34495e;
    border-radius: 8px;
    cursor: pointer;
    text-align: center;
    transition: background 0.3s ease, transform 0.2s ease;
}

.sidebar ul li:hover {
    background: #16a085;
    transform: scale(1.05);
}

.subsection {
    display: none;
    margin-left: 15px;
}

.subsection li {
    margin: 8px 0;
    background-color: #3b4f63;
    border-radius: 6px;
}

.content {
    flex: 1;
    background: #ffffff;
    padding: 30px;
    overflow-y: auto;
    border-radius: 10px;
    margin: 20px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.content h3 {
    font-size: 2rem;
    margin-bottom: 10px;
    color: #2c3e50;
    border-bottom: 2px solid #16a085;
    display: inline-block;
}

.content p {
    line-height: 1.8;
    color: #34495e;
    font-size: 1rem;
    margin-top: 10px;
}

/* Smooth toggle transitions */
.subsection {
    transition: max-height 0.3s ease;
    overflow: hidden;
}

/* Add hover effects to links */
ul li {
    transition: background-color 0.3s, box-shadow 0.3s;
}

ul li:hover {
    box-shadow: 0px 4px 10px rgba(22, 160, 133, 0.5);
}

/* Add scrollbar styling */
.sidebar,
.content {
    scrollbar-width: thin;
    scrollbar-color: #16a085 #ecf0f1;
}

.sidebar::-webkit-scrollbar,
.content::-webkit-scrollbar {
    width: 8px;
}

.sidebar::-webkit-scrollbar-thumb,
.content::-webkit-scrollbar-thumb {
    background-color: #16a085;
    border-radius: 10px;
}

.sidebar::-webkit-scrollbar-track,
.content::-webkit-scrollbar-track {
    background: #ecf0f1;
}