* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #f3f4f6;
    color: #111827;
}

header {
    background: linear-gradient(135deg, #1d4ed8, #3b82f6);
    color: #ffffff;
    padding: 24px 16px;
}

header .container {
    max-width: 960px;
    margin: 0 auto;
}

header h1 {
    margin: 0 0 8px;
    font-size: 1.8rem;
}

header p {
    margin: 4px 0;
    font-size: 0.95rem;
    opacity: 0.95;
}

main {
    max-width: 960px;
    margin: 24px auto 40px;
    padding: 0 16px;
}

.grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}

@media (min-width: 768px) {
    .grid {
        grid-template-columns: 1.1fr 0.9fr;
    }
}

.card {
    background: #ffffff;
    border-radius: 8px;
    padding: 16px 18px;
    box-shadow: 0 4px 10px rgba(15, 23, 42, 0.08);
}

.card h2 {
    margin-top: 0;
    font-size: 1.2rem;
    margin-bottom: 8px;
}

.card p {
    margin: 4px 0 10px;
    font-size: 0.95rem;
    color: #4b5563;
}

label {
    display: block;
    font-size: 0.9rem;
    margin-bottom: 4px;
    color: #374151;
}

input, select {
    width: 100%;
    padding: 8px 10px;
    margin-bottom: 10px;
    border-radius: 6px;
    border: 1px solid #d1d5db;
    font-size: 0.9rem;
}

input:focus, select:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 1px rgba(59, 130, 246, 0.3);
}

button {
    display: inline-block;
    padding: 8px 14px;
    border-radius: 6px;
    border: none;
    font-size: 0.9rem;
    cursor: pointer;
    background: #2563eb;
    color: #ffffff;
}

button.secondary {
    background: #6b7280;
}

button:disabled {
    opacity: 0.6;
    cursor: default;
}

.small {
    font-size: 0.85rem;
    color: #6b7280;
}

.muted {
    font-size: 0.85rem;
    color: #9ca3af;
}

.message {
    font-size: 0.9rem;
    margin-top: 6px;
}

.message.success {
    color: #15803d;
}

.message.error {
    color: #b91c1c;
}

.pill {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 999px;
    font-size: 0.75rem;
    background: #e5e7eb;
    color: #374151;
    margin-right: 4px;
    margin-bottom: 4px;
}

.courses-list {
    margin-top: 8px;
}

.course-item {
    padding: 8px 10px;
    border-radius: 6px;
    border: 1px solid #e5e7eb;
    margin-bottom: 6px;
    background: #f9fafb;
}

.course-item h3 {
    margin: 0 0 4px;
    font-size: 0.98rem;
}

.course-item p {
    margin: 0;
    font-size: 0.85rem;
    color: #4b5563;
}

.stats-box {
    margin-top: 8px;
    font-size: 0.9rem;
}

.stats-box div {
    margin-bottom: 2px;
}

footer {
    text-align: center;
    padding: 16px;
    font-size: 0.8rem;
    color: #9ca3af;
}