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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: #1a1a1a;
    background: #f8f8f8;
    line-height: 1.6;
}

header {
    background: #1a1a1a;
    color: white;
    padding: 2rem;
    text-align: center;
}

header h1 { font-size: 2rem; margin-bottom: 0.25rem; }
header p { opacity: 0.8; font-size: 1.1rem; }

.back-link {
    display: inline-block;
    color: #aaa;
    text-decoration: none;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}
.back-link:hover { color: white; }

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

.drill-list { display: flex; flex-direction: column; gap: 1rem; }

.drill-card {
    display: block;
    background: white;
    border-radius: 8px;
    padding: 1.5rem;
    text-decoration: none;
    color: inherit;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    transition: box-shadow 0.2s;
}
.drill-card:hover { box-shadow: 0 4px 12px rgba(0,0,0,0.15); }
.drill-card h2 { font-size: 1.25rem; margin-bottom: 0.25rem; }
.drill-card p { color: #666; font-size: 0.95rem; margin-bottom: 0.5rem; }

.key-badge {
    display: inline-block;
    background: #e8e8e8;
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
}
.date { float: right; color: #999; font-size: 0.8rem; }

.download-section { margin-bottom: 2rem; }
.download-section h2 { margin-bottom: 1rem; font-size: 1.2rem; }

.key-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 0.75rem;
}

.download-btn {
    display: block;
    text-align: center;
    padding: 0.75rem 1rem;
    background: #1a1a1a;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 500;
    transition: background 0.2s;
}
.download-btn:hover { background: #333; }

.download-all {
    background: #2563eb;
    font-size: 1.1rem;
    padding: 1rem;
}
.download-all:hover { background: #1d4ed8; }

.original-key { background: #059669; }
.original-key:hover { background: #047857; }

.badge {
    display: inline-block;
    background: rgba(255,255,255,0.2);
    padding: 0.1rem 0.4rem;
    border-radius: 3px;
    font-size: 0.7rem;
    margin-left: 0.25rem;
}

footer {
    text-align: center;
    padding: 2rem;
    color: #999;
    font-size: 0.85rem;
}