:root {
    --brand: #6a1b9a;
    --brand-dark: #4a148c;
    --bg: #f5f3fa;
    --card-bg: #ffffff;
    --text: #26202b;
    --muted: #6b6470;
    --border: #e3ddee;
    --success: #2e7d32;
    --warning: #ef6c00;
    --danger: #c62828;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}

.site-header {
    background: var(--brand);
    color: #fff;
}
.site-header-inner {
    max-width: 1000px;
    margin: 0 auto;
    padding: 14px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.brand {
    color: #fff;
    text-decoration: none;
    font-size: 1.3rem;
    font-weight: 700;
}
.nav { display: flex; align-items: center; gap: 16px; }
.nav-user { font-size: 0.9rem; opacity: 0.9; }
.nav-logout {
    color: #fff;
    background: rgba(255,255,255,0.15);
    padding: 6px 14px;
    border-radius: 6px;
    text-decoration: none;
    font-size: 0.9rem;
}
.nav-logout:hover { background: rgba(255,255,255,0.3); }

.site-main {
    max-width: 1000px;
    margin: 30px auto;
    padding: 0 20px;
}

.site-footer {
    text-align: center;
    color: var(--muted);
    font-size: 0.85rem;
    padding: 20px;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 20px;
}

h1 { color: var(--brand-dark); }
h2 { color: var(--brand-dark); font-size: 1.2rem; margin-top: 0; }

table {
    width: 100%;
    border-collapse: collapse;
}
th, td {
    text-align: left;
    padding: 10px;
    border-bottom: 1px solid var(--border);
    font-size: 0.95rem;
}
th { color: var(--muted); font-weight: 600; }

.badge {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}
.badge-paid    { background: #e8f5e9; color: var(--success); }
.badge-pending { background: #fff3e0; color: var(--warning); }
.badge-overdue { background: #ffebee; color: var(--danger); }

.btn {
    display: inline-block;
    background: var(--brand);
    color: #fff;
    padding: 10px 18px;
    border: none;
    border-radius: 6px;
    text-decoration: none;
    font-size: 1rem;
    cursor: pointer;
}
.btn:hover { background: var(--brand-dark); }

.login-wrap {
    max-width: 380px;
    margin: 60px auto;
}
.form-field { margin-bottom: 14px; }
.form-field label { display: block; margin-bottom: 6px; font-size: 0.9rem; color: var(--muted); }
.form-field input {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 1rem;
}
.error-box {
    background: #ffebee;
    color: var(--danger);
    padding: 10px 14px;
    border-radius: 6px;
    margin-bottom: 16px;
    font-size: 0.9rem;
}
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
}
.stat {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 16px;
    text-align: center;
}
.stat .num { font-size: 1.8rem; font-weight: 700; color: var(--brand); }
.stat .label { color: var(--muted); font-size: 0.85rem; }