:root {
    --bg-base: #f6f7fb;
    --surface: #ffffff;
    --border: #e5e7eb;
    --text: #111827;
    --muted: #6b7280;
    --primary: #1f5fbf;
    --primary-dark: #174a95;
    --info: #0f9fbf;
    --warning: #f2b33d;
    --danger: #d14343;
}

html {
    font-size: 14px;
    position: relative;
    min-height: 100%;
}

@media (min-width: 768px) {
    html { font-size: 16px; }
}

body {
    margin-bottom: 60px;
    background-color: var(--bg-base);
    color: var(--text);
    font-family: 'Inter', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

/* NAVBAR */
.bg-dark { background-color: #161d2f !important; }

.navbar { box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08); }
.navbar-brand { letter-spacing: 0.4px; }
.nav-link {
    font-weight: 500;
    opacity: 0.9;
    transition: opacity 0.2s ease-in-out, transform 0.15s ease-in-out;
}
.nav-link:hover {
    opacity: 1;
    transform: translateY(-1px);
}

/* CONTENEDOR GENERAL */
.container, .container-xl { animation: fadeIn 0.35s ease-out; }

/* TARJETAS */
.card-custom {
    background: var(--surface);
    border-radius: 10px;
    padding: 28px;
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.05);
    margin-top: 20px;
    border: 1px solid var(--border);
}

/* TITULOS */
h1, h2, h3 {
    color: #0f172a;
    font-weight: 650;
    margin-bottom: 1.25rem;
}

/* TABLAS */
.table {
    background: var(--surface);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.04);
    border: 1px solid var(--border);
}

.table thead {
    background-color: #f8fafc;
    color: #374151;
    border-bottom: 2px solid var(--border);
}

.table th {
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 0.35px;
}

.table th, .table td {
    vertical-align: middle;
    padding: 0.95rem 1rem;
}

.table tbody tr:hover { background-color: #f1f5f9; }

/* BOTONES */
.btn {
    font-weight: 600;
    border-radius: 7px;
    padding: 0.55rem 1.05rem;
    transition: all 0.2s ease-in-out;
}

.btn:focus { box-shadow: 0 0 0 0.18rem rgba(31, 95, 191, 0.25); }

.btn-primary {
    background-color: var(--primary);
    border-color: var(--primary);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
    box-shadow: 0 3px 8px rgba(31, 95, 191, 0.35);
}

.btn-secondary {
    background-color: #5b6472;
    border-color: #5b6472;
}

.btn-info {
    background-color: var(--info);
    border-color: var(--info);
    color: white;
}

.btn-info:hover {
    background-color: #0c86a1;
    border-color: #0c86a1;
    color: white;
}

.btn-warning {
    background-color: var(--warning);
    border-color: var(--warning);
    color: #2d2a22;
}

.btn-danger {
    background-color: var(--danger);
    border-color: var(--danger);
}

.btn-sm {
    padding: 0.35rem 0.7rem;
    font-size: 0.875rem;
}

/* INPUTS */
.form-control, .form-select {
    border-radius: 8px;
    border: 1px solid var(--border);
    padding: 0.55rem 0.8rem;
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.02);
    background-color: #fbfcfe;
}

.form-control:focus, .form-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 0.18rem rgba(31, 95, 191, 0.15);
}

/* FOOTER */
.footer {
    background-color: var(--surface);
    border-top: 1px solid var(--border) !important;
    color: var(--muted);
    padding: 16px 0;
}

/* ANIMACION */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}