.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: var(--sidebar-width);
    height: 100vh;
    background: var(--surface);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    z-index: 1000;
    box-shadow: var(--shadow-md);
}

.sidebar-content {
    flex: 1;
    overflow-y: auto;
    padding: 0;
}

.sidebar-back {
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border);
    background: var(--surface);
}

.sidebar-back a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9375rem;
    transition: all var(--transition);
}

.sidebar-back a:hover {
    color: var(--primary-color);
}

.sidebar-back a::before {
    content: '←';
    font-size: 1.25rem;
}

.sidebar-header {
    padding: 2.5rem 2rem;
    border-bottom: 1px solid var(--border);
    background: var(--surface);
}

.sidebar-header h2 {
    font-size: 1.625rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.sidebar-nav {
    padding: 2rem 0;
}

.nav-category {
    margin-bottom: 2rem;
}

.nav-category h3 {
    padding: 0 2rem 0.75rem 2rem;
    font-size: 0.8125rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-tertiary);
}

.nav-category ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.nav-category ul li {
    margin: 0;
}

.nav-category ul li a {
    display: flex;
    align-items: center;
    padding: 0.875rem 2rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition);
    border-left: 3px solid transparent;
    font-weight: 500;
    font-size: 0.9375rem;
    position: relative;
}

.nav-category ul li a::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 3px;
    background: var(--primary-color);
    opacity: 0;
    transition: opacity var(--transition);
}

.nav-category ul li a:hover {
    background: var(--primary-light);
    color: var(--text-primary);
    padding-left: 2.25rem;
}

.nav-category ul li a:hover::before {
    opacity: 0.3;
}

.nav-category ul li a.active {
    background: var(--primary-light);
    color: var(--primary-color);
    font-weight: 600;
}

.nav-category ul li a.active::before {
    opacity: 1;
}

.sidebar-footer {
    padding: 2rem;
    border-top: 1px solid var(--border);
    background: var(--surface);
}

.sidebar-footer p {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
    text-align: center;
    font-weight: 500;
    margin: 0.25rem 0;
}

.sidebar-footer a {
    color: var(--text-secondary);
    text-decoration: underline;
    transition: color var(--transition);
}

.sidebar-footer a:hover {
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform var(--transition);
    }

    .sidebar.open {
        transform: translateX(0);
    }
}