body {
    font-family: 'Poppins', sans-serif;
    background-color: #e9ecef;
    overflow-x: hidden;
    margin: 0;
}
.sidebar {
    width: 260px;
    height: 100%;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    background: linear-gradient(180deg, #ffffff 0%, #f8f9fa 100%);
    box-shadow: 2px 0 5px rgba(0,0,0,0.1);
    z-index: 1000;
    overflow-y: auto;
    transition: transform 0.3s ease;
}
.sidebar.collapsed {
    transform: translateX(-260px);
}
.sidebar .logo {
    padding: 20px;
    text-align: center;
    border-bottom: 1px solid #dee2e6;
}
.sidebar .logo h4 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #343a40;
    margin: 0;
}
.sidebar .nav-link {
    color: #495057;
    padding: 12px 20px;
    border-radius: 8px;
    margin: 5px 10px;
    display: flex;
    align-items: center;
    transition: background 0.3s, color 0.3s;
}
.sidebar .nav-link:hover, .sidebar .nav-link.active {
    background: #007bff;
    color: #fff;
}
.sidebar .nav-link i {
    margin-right: 12px;
    font-size: 1.2rem;
    width: 20px;
    text-align: center;
}
.topbar {
    background: #fff;
    padding: 15px 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.08);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1100;
    transition: left 0.3s ease;
}
.content {
    margin-top: 70px;
    padding: 25px;
    transition: margin-left 0.3s ease;
}
.backdrop {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 900;
}
.backdrop.active {
    display: block;
}
.card {
    border: none;
    border-radius: 12px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}
.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}
.table {
    background: #fff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
}
.form-control {
    border-radius: 8px;
    border: 1px solid #ced4da;
}
.btn-primary {
    background: #007bff;
    border: none;
    border-radius: 8px;
    padding: 10px 20px;
}
.btn-primary:hover {
    background: #0056b3;
}
.btn-secondary {
    background: #6c757d;
    border: none;
    border-radius: 8px;
    padding: 8px 16px;
}
.btn-secondary:hover {
    background: #5a6268;
}
.btn-danger {
    border-radius: 8px;
    padding: 8px 16px;
}
.column-row {
    background: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 8px;
    padding: 10px;
}
@media (min-width: 769px) {
    .sidebar {
        transform: translateX(0);
        transition: width 0.3s ease;
    }
    .sidebar.collapsed {
        width: 70px;
        transform: none;
    }
    .sidebar.collapsed .nav-link span {
        display: none;
    }
    .sidebar.collapsed .nav-link i {
        margin-right: 0;
    }
    .sidebar.collapsed .logo h4 {
        font-size: 0;
    }
    .sidebar.collapsed .logo h4::before {
        content: 'AP';
        font-size: 1.2rem;
        display: block;
    }
    .topbar {
        left: 260px;
    }
    .topbar.collapsed {
        left: 70px;
    }
    .content {
        margin-left: 260px;
    }
    .content.collapsed {
        margin-left: 70px;
    }
}
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-260px);
    }
    .sidebar.active {
        transform: translateX(0);
    }
    .topbar {
        left: 0;
    }
    .content {
        margin-left: 0;
    }
}