body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}
.sidebar {
    background-color: #343a40;
    min-height: 100vh;
    position: fixed;
    width: 250px;
    top: 0;
    left: 0;
    z-index: 1000;
    overflow-y: auto;
    max-height: 100vh;
    transition: width 0.3s ease;
}
.sidebar::-webkit-scrollbar {
    width: 8px;
}
.sidebar::-webkit-scrollbar-thumb {
    background: #495057;
    border-radius: 6px;
}
.sidebar.collapsed {
    width: 70px;
}
.sidebar.collapsed .sidebar-text,
.sidebar.collapsed .sidebar-search,
.sidebar.collapsed .nav-section,
.sidebar.collapsed h4 .sidebar-text,
.sidebar.collapsed .mb-2 {
    display: none;
}
.sidebar .nav {
    padding-bottom: 20px;
}
.sidebar .nav-link {
    color: #adb5bd;
    padding: 8px 16px;
    font-size: 0.9rem;
    margin-bottom: 2px;
    border-radius: 5px;
    display: flex;
    align-items: center;
    gap: 10px;
}
.sidebar .nav-link:hover,
.sidebar .nav-link.active {
    background-color: #495057;
    color: #fff;
}
.sidebar .nav-link.active {
    box-shadow: inset 3px 0 0 #0d6efd;
}
.sidebar .nav-link i {
    width: 20px;
    text-align: center;
}
.sidebar h4 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
}
.nav-section {
    list-style: none;
    margin-top: 6px;
}
.nav-section-btn {
    width: 100%;
    background: transparent;
    border: 0;
    color: #6c757d;
    font-size: 0.75rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    padding: 8px 16px 4px;
    text-align: left;
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    border-radius: 6px;
    transition: color 0.2s ease, background-color 0.2s ease;
}
.nav-section-btn:hover {
    color: #dee2e6;
    background-color: rgba(255, 255, 255, 0.05);
}
.nav-section-btn .section-caret {
    display: inline-block;
    transform: rotate(90deg);
    transition: transform 0.2s ease;
}
.nav-section-btn[aria-expanded="false"] .section-caret {
    transform: rotate(0deg);
}
.sidebar-search {
    position: relative;
    margin-bottom: 12px;
}
.sidebar-search input {
    background: #2d3238;
    border: 1px solid #444a51;
    color: #e9ecef;
    padding-left: 32px;
}
.sidebar-search input::placeholder {
    color: #f8f9fa;
    opacity: 1;
}
.sidebar-search i {
    position: absolute;
    top: 50%;
    left: 10px;
    transform: translateY(-50%);
    color: #6c757d;
    pointer-events: none;
}
.main-content {
    margin-left: 250px;
    padding: 20px;
    transition: margin-left 0.3s ease;
}
.sidebar.collapsed ~ .main-content {
    margin-left: 70px;
}
@media (max-width: 768px) {
    .sidebar {
        width: 100%;
        position: relative;
        min-height: auto;
    }
    .main-content {
        margin-left: 0;
    }
}