.sidebar {
    width: var(--sidebar-width);
    background: transparent;
    overflow-y: auto;
    position: sticky;
    top: 0;
    height: 100vh;
    z-index: 1;
    display: flex;
    flex-direction: column;
    padding: 16px 16px 50px 0;
    box-sizing: border-box;
    scroll-behavior: smooth;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color) transparent;
}

.sidebar::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-thumb {
    background-color: var(--surface-variant);
    border-radius: var(--shape-pill);
}

.sidebar::-webkit-scrollbar-thumb:hover {
    background-color: var(--primary-color);
}

.sidebar-bg {
    position: absolute;
    left: 0;
    top: 0;
    width: var(--sidebar-width);
    height: 100%;
    background: var(--surface-color);
    border-right: 1px solid var(--border-color);
    z-index: 0;
    transition: var(--transition-theme);
}

.sidebar-menu ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-menu li {
    margin: 2px 0;
    padding: 0;
}

.sidebar-menu a {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    padding: 10px 12px 10px 16px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.95rem;
    border-radius: 0 var(--shape-pill) var(--shape-pill) 0;
    transition: all var(--transition-duration) var(--md-easing);
    line-height: 1.4;
}

.sidebar-menu a:hover {
    background: var(--hover-overlay);
}

.sidebar-menu a.active {
    color: var(--on-primary);
    background: var(--primary-color);
    font-weight: 500;
}

.sidebar-item {
    position: relative;
}

.submenu {
    max-height: 0;
    overflow: hidden;
    padding: 0;
    margin: 0;
    list-style: none;
    transition: max-height 0.3s var(--md-easing);
}

.sidebar-item.has-submenu .submenu {
    max-height: 1000px;
}

.sidebar-item.collapsed .submenu {
    max-height: 0;
}

.sidebar-menu .submenu a {
    padding: 8px 16px 8px 48px;
    font-size: 0.88rem;
    color: var(--text-secondary);
    position: relative;
}

.sidebar-menu .submenu a:hover {
    color: var(--text-primary);
    background: var(--hover-overlay);
}

.sidebar-menu .submenu a.active {
    color: var(--primary-color);
    background: var(--active-overlay);
    font-weight: 600;
}

.sidebar-menu .submenu a::before {
    content: '';
    position: absolute;
    left: 26px;
    top: 0;
    bottom: 0;
    width: 1px;
    background-color: var(--border-color);
    transition: background-color var(--transition-duration);
}

.sidebar-menu .submenu a.active::before {
    background-color: var(--primary-color);
    width: 2px;
}

.submenu-toggle {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: inherit;
    border-radius: 50%;
    transition: transform var(--transition-duration) var(--md-easing), background-color var(--transition-duration);
    transform: rotate(90deg);
}

.submenu-toggle:hover {
    background-color: var(--hover-overlay);
}

.sidebar-item.collapsed .submenu-toggle {
    transform: rotate(0);
}

.sidebar-controls {
    display: flex;
    gap: 8px;
    padding: 0 16px 16px 16px;
    margin-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.toggle-all, .sort-subitems {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    flex: 1;
    padding: 6px 12px;
    background: var(--surface-variant);
    color: var(--text-primary);
    border: none;
    border-radius: var(--shape-small);
    cursor: pointer;
    font-size: 0.85rem;
    font-family: var(--font-ui);
    transition: background-color var(--transition-duration);
}

.toggle-all:hover, .sort-subitems:hover {
    background: var(--hover-overlay);
}

.sort-subitems.sorted {
    color: var(--primary-color);
    background: var(--active-overlay);
}

.search-container {
    padding: 0 16px 12px 16px;
    flex-shrink: 0;
}

.sidebar-search {
    width: 100%;
    box-sizing: border-box;
    padding: 10px 16px;
    border: 1px solid var(--border-color);
    border-radius: var(--shape-pill);
    background: var(--surface-variant);
    color: var(--text-primary);
    font-size: 0.95rem;
    font-family: var(--font-ui);
    transition: all var(--transition-duration);
}

.sidebar-search:focus {
    outline: none;
    border-color: var(--color-h2);
    background: var(--surface-color);
    box-shadow: 0 0 0 3px rgba(108, 182, 255, 0.15);
}

[data-theme="light"] .sidebar-search:focus {
    box-shadow: 0 0 0 3px rgba(0, 92, 197, 0.15);
}