:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --error: #ef4444;
    --success: #22c55e;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.5;
}

.container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 2rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

h1, h2, h3 {
    margin-bottom: 1rem;
}

.form-group {
    margin-bottom: 1rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

input, textarea, select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: 1rem;
}

button {
    background: var(--primary);
    color: white;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 4px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s;
}

button:hover {
    background: var(--primary-hover);
}

button.secondary {
    background: var(--text-muted);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border);
}

.nav a {
    color: var(--primary);
    text-decoration: none;
    margin-left: 1rem;
}

.alert {
    padding: 1rem;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.alert-error {
    background: #fee2e2;
    color: var(--error);
    border: 1px solid #fecaca;
}

.alert-success {
    background: #dcfce7;
    color: var(--success);
    border: 1px solid #bbf7d0;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.badge {
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.875rem;
    font-weight: 600;
}

.badge-free { background: #e2e8f0; }
.badge-paid { background: #dcfce7; color: #166534; }

.hidden { display: none; }

/* Responsive adjustments */
@media (max-width: 640px) {
    .container { margin: 1rem auto; }
    .card { padding: 1rem; }
}