:root {
    --bg-main: #f4f7fc;
    --sidebar-bg: #e3edf9;
    --sidebar-active: #c2d8f6;
    --primary-blue: #6c9bcf;
    --primary-hover: #4a82c1;
    --card-bg: #ffffff;
    --text-color: #2c3e50;
    --border-radius: 20px;
    --input-radius: 12px;
}

body {
    background-color: var(--bg-main);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-color);
    margin: 0;
}

/* Layout Principal */
.app-container {
    display: flex;
    min-height: 100vh;
}

/* Menú Lateral Izquierdo */
.sidebar {
    width: 260px;
    background-color: var(--sidebar-bg);
    padding: 2rem 1rem;
    box-shadow: 4px 0 15px rgba(0, 0, 0, 0.03);
    display: flex;
    flex-direction: column;
}

.sidebar .brand-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-hover);
    text-align: center;
    margin-bottom: 2rem;
}

.sidebar .nav-link {
    color: var(--text-color);
    padding: 0.8rem 1.2rem;
    margin-bottom: 0.5rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: all 0.3s ease;
}

.sidebar .nav-link:hover, 
.sidebar .nav-link.active {
    background-color: var(--sidebar-active);
    color: #1a4971;
    transform: translateX(4px);
}

/* Área de Contenido */
.main-content {
    flex: 1;
    padding: 2.5rem;
    overflow-y: auto;
}

/* Tarjetas y Paneles Vanguardistas */
.card-custom {
    background: var(--card-bg);
    border: none;
    border-radius: var(--border-radius);
    box-shadow: 0 10px 25px rgba(108, 155, 207, 0.08);
    padding: 1.8rem;
    margin-bottom: 1.5rem;
}

/* Inputs y Botones Ovalados */
.form-control, .form-select {
    border-radius: var(--input-radius);
    border: 1px solid #d0e1f9;
    padding: 0.65rem 1rem;
    background-color: #fafcff;
}

.form-control:focus, .form-select:focus {
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 0.25rem rgba(108, 155, 207, 0.25);
}

.btn-custom {
    background-color: var(--primary-blue);
    color: white;
    border-radius: 25px; /* Botón ovalado */
    padding: 0.6rem 1.8rem;
    font-weight: 600;
    border: none;
    transition: all 0.3s ease;
}

.btn-custom:hover {
    background-color: var(--primary-hover);
    color: white;
    box-shadow: 0 5px 12px rgba(74, 130, 193, 0.3);
}

/* Tablas Estilizadas */
.table {
    border-collapse: separate;
    border-spacing: 0 8px;
}

.table tbody tr {
    background-color: #ffffff;
    box-shadow: 0 2px 6px rgba(0,0,0,0.02);
    border-radius: 10px;
}

.table tbody td {
    padding: 1rem;
    vertical-align: middle;
}