:root {
    --primary: #2c5282;
    --primary-light: #4299e1;
    --success: #38a169;
    --warning: #d69e2e;
    --danger: #e53e3e;
    --bg: #f7fafc;
    --card-bg: rgba(255,255,255,0.7);
    --text: #1a202c;
    --border: rgba(255,255,255,0.3);
    --shadow: 0 8px 32px rgba(31,38,135,0.15);
}
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #1a202c;
        --card-bg: rgba(26,32,44,0.7);
        --text: #f7fafc;
    }
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    background-attachment: fixed;
    color: var(--text);
    min-height: 100vh;
}
.glass {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: 16px;
    box-shadow: var(--shadow);
}
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}
.nav-brand { display: flex; align-items: center; gap: 0.75rem; font-weight: 700; font-size: 1.25rem; }
.nav-links { display: flex; gap: 1.5rem; align-items: center; }
.nav-links a { text-decoration: none; color: var(--text); opacity: 0.8; transition: 0.2s; }
.nav-links a:hover, .nav-links a.active { opacity: 1; color: var(--primary-light); }
.nav-logout { color: var(--danger) !important; }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; color: var(--text); }
.main-content { max-width: 1200px; margin: 0 auto; padding: 2rem; }
.page-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1.5rem; flex-wrap: wrap; gap: 1rem; }
.page-header h1 { font-size: 1.75rem; }
.subtitle { opacity: 0.8; font-size: 1rem; }
.btn {
    display: inline-flex; align-items: center; gap: 0.5rem;
    padding: 0.6rem 1.2rem; border-radius: 10px; border: none;
    font-size: 0.95rem; font-weight: 500; cursor: pointer;
    text-decoration: none; transition: all 0.2s;
}
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-light); transform: translateY(-1px); }
.btn-secondary { background: rgba(255,255,255,0.3); color: var(--text); border: 1px solid var(--border); }
.btn-secondary:hover { background: rgba(255,255,255,0.5); }
.btn-ghost { background: transparent; color: var(--text); }
.btn-ghost:hover { background: rgba(255,255,255,0.2); }
.btn-block { width: 100%; justify-content: center; }
.btn-lg { padding: 0.85rem 1.5rem; font-size: 1.05rem; }
.btn-sm { padding: 0.4rem 0.8rem; font-size: 0.85rem; }
.alert { padding: 1rem; border-radius: 10px; margin-bottom: 1rem; animation: fadeIn 0.3s ease; }
.alert-success { background: rgba(56,161,105,0.15); color: #276749; border: 1px solid rgba(56,161,105,0.3); }
.alert-error { background: rgba(229,62,62,0.15); color: #c53030; border: 1px solid rgba(229,62,62,0.3); }
.alert-warning { background: rgba(214,158,46,0.15); color: #975a16; border: 1px solid rgba(214,158,46,0.3); }
@keyframes fadeIn { from { opacity: 0; transform: translateY(-10px); } to { opacity: 1; transform: translateY(0); } }
.login-container { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 2rem; }
.login-card { width: 100%; max-width: 420px; padding: 2.5rem; }
.login-header { text-align: center; margin-bottom: 2rem; }
.login-header h1 { font-size: 1.5rem; margin-top: 1rem; color: var(--text); }
.login-header p { opacity: 0.7; margin-top: 0.25rem; }
.login-icon { color: var(--primary); }
.login-form { display: flex; flex-direction: column; gap: 1.25rem; }
.login-footer { text-align: center; margin-top: 1.5rem; opacity: 0.7; }
.form-group { display: flex; flex-direction: column; gap: 0.4rem; margin-bottom: 1rem; }
.form-group label { font-size: 0.9rem; font-weight: 500; opacity: 0.9; }
.form-group small { font-size: 0.8rem; opacity: 0.7; }
.form-group input, .form-group select, .form-group textarea {
    padding: 0.65rem 0.9rem; border-radius: 10px; border: 1px solid var(--border);
    background: rgba(255,255,255,0.5); font-size: 1rem; color: var(--text);
    outline: none; transition: border-color 0.2s;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
    border-color: var(--primary-light);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.form-actions { display: flex; gap: 1rem; margin-top: 1.5rem; flex-wrap: wrap; }
.form-section-title { margin: 1.5rem 0 0.5rem; font-size: 1.1rem; color: var(--primary); }
.checkbox-group { background: rgba(255,255,255,0.2); padding: 1rem; border-radius: 10px; }
.checkbox-label { display: flex; align-items: center; gap: 0.75rem; cursor: pointer; }
.checkbox-label input { width: 18px; height: 18px; accent-color: var(--primary); }
.dashboard-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1.25rem; margin-bottom: 2rem; }
.stat-card { padding: 1.5rem; text-align: center; transition: transform 0.2s; }
.stat-card:hover { transform: translateY(-3px); }
.stat-icon { margin-bottom: 0.75rem; }
.stat-value { font-size: 1.75rem; font-weight: 700; margin-bottom: 0.25rem; }
.stat-label { font-size: 0.9rem; opacity: 0.8; }
.dashboard-actions { display: flex; gap: 1rem; margin-bottom: 2rem; flex-wrap: wrap; }
.search-bar { padding: 1rem; margin-bottom: 1.5rem; }
.search-form { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.search-form input, .search-form select { flex: 1; min-width: 200px; padding: 0.6rem; border-radius: 8px; border: 1px solid var(--border); background: rgba(255,255,255,0.4); color: var(--text); }
.section { padding: 1.5rem; margin-bottom: 1.5rem; }
.data-table { width: 100%; border-collapse: collapse; }
.data-table th, .data-table td { padding: 0.85rem; text-align: left; border-bottom: 1px solid var(--border); }
.data-table th { font-weight: 600; opacity: 0.8; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; }
.data-table tr:hover { background: rgba(255,255,255,0.1); }
.data-table td.text-right { text-align: right; }
.badge { display: inline-block; padding: 0.25rem 0.6rem; border-radius: 20px; font-size: 0.8rem; font-weight: 500; }
.badge-primary { background: var(--primary); color: white; }
.badge-success { background: var(--success); color: white; }
.badge-muted { background: rgba(0,0,0,0.2); color: var(--text); }
.row-muted { opacity: 0.6; }
.actions { display: flex; gap: 0.5rem; }
.iniciales-bar { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 1rem; }
.inicial-tag { padding: 0.3rem 0.7rem; border-radius: 8px; background: rgba(255,255,255,0.3); text-decoration: none; color: var(--text); font-weight: 600; font-size: 0.9rem; transition: all 0.2s; }
.inicial-tag:hover { background: var(--primary); color: white; }
.cards-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 1rem; margin-top: 1rem; }
.card-persona { padding: 1rem; text-decoration: none; color: var(--text); transition: transform 0.2s; }
.card-persona:hover { transform: translateY(-3px); }
.card-name { font-weight: 600; margin-bottom: 0.25rem; }
.card-meta { font-size: 0.85rem; opacity: 0.7; }
.cobro-persona { padding: 1.25rem; margin-bottom: 1.5rem; }
.cobro-persona h3 { margin-bottom: 0.5rem; }
.pagination { display: flex; gap: 0.4rem; margin-top: 1rem; justify-content: center; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-muted { opacity: 0.7; }
.table-responsive { overflow-x: auto; }
@media (max-width: 768px) {
    .nav-links { display: none; position: absolute; top: 60px; left: 0; right: 0; background: var(--card-bg); flex-direction: column; padding: 1rem; gap: 1rem; backdrop-filter: blur(12px); border-bottom: 1px solid var(--border); }
    .nav-links.active { display: flex; }
    .nav-toggle { display: block; }
    .form-row { grid-template-columns: 1fr; }
    .main-content { padding: 1rem; }
    .page-header { flex-direction: column; align-items: flex-start; }
    .dashboard-grid { grid-template-columns: 1fr 1fr; }
    .stat-value { font-size: 1.4rem; }
}

.cuotas-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 1rem; margin: 1.5rem 0; }
.btn-cuota { display: flex; flex-direction: column; align-items: center; gap: 0.5rem; padding: 1.5rem; border: 2px solid var(--border); background: rgba(255,255,255,0.3); color: var(--text); cursor: pointer; transition: all 0.2s; text-decoration: none; }
.btn-cuota:hover { background: var(--primary); color: white; border-color: var(--primary); transform: translateY(-3px); }
.cuota-tipo { font-size: 1.1rem; font-weight: 600; }
.cuota-importe { font-size: 1.5rem; font-weight: 700; }