:root {
    --bg: #f5f5f5;
    --card: #ffffff;
    --text: #222;
    --muted: #666;
    --primary: #0066cc;
    --primary-dark: #004a99;
    --error: #cc0033;
    --border: #e0e0e0;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.5;
}

header {
    background: var(--card);
    padding: 1rem 2rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 500;
}

#user-info {
    color: var(--muted);
    font-size: 0.9rem;
}

main {
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.card {
    background: var(--card);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border);
}

.card h2 {
    margin: 0 0 1rem;
    font-size: 1.1rem;
    font-weight: 500;
}

.hidden { display: none; }

form label {
    display: block;
    margin-bottom: 0.75rem;
    color: var(--muted);
    font-size: 0.9rem;
}

form input, .chart-controls select {
    display: block;
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: 1rem;
    margin-top: 0.25rem;
    color: var(--text);
    background: var(--card);
}

form input:focus, .chart-controls select:focus {
    outline: 2px solid var(--primary);
    outline-offset: -1px;
}

button {
    background: var(--primary);
    color: white;
    border: none;
    padding: 0.6rem 1.25rem;
    border-radius: 4px;
    font-size: 1rem;
    cursor: pointer;
    margin-top: 0.5rem;
}

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

button.link {
    background: transparent;
    color: var(--muted);
    padding: 0;
    font-size: 0.9rem;
    text-decoration: underline;
}

button.link:hover { color: var(--text); }

.error {
    color: var(--error);
    font-size: 0.9rem;
    margin-top: 0.5rem;
    min-height: 1.2em;
}

.chart-controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.chart-controls label {
    flex: 1;
    min-width: 120px;
}

#chart {
    max-height: 400px;
}

#apartments .apartment {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border);
}

#apartments .apartment:last-child { border-bottom: none; }

#stats {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
    color: var(--muted);
    font-size: 0.9rem;
}

#stats dl {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 0.25rem 1rem;
    margin: 0;
}

#stats dt { font-weight: 500; color: var(--text); }
#stats dd { margin: 0; }
.live-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1rem;
    margin-top: 0.5rem;
}

.live-tile {
    padding: 1rem;
    background: var(--bg);
    border-radius: 6px;
    border: 1px solid var(--border);
}

.live-tile .label {
    font-size: 0.8rem;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.live-tile .value {
    font-size: 1.6rem;
    font-weight: 500;
    margin-top: 0.25rem;
    color: var(--primary-dark);
}

.live-tile .unit {
    font-size: 1rem;
    color: var(--muted);
    margin-left: 0.25rem;
    font-weight: 400;
}

.live-meta {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
    color: var(--muted);
    font-size: 0.85rem;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.status-ok { color: #2b8a3e; }
.status-err { color: var(--error); }

.placeholder {
    color: var(--muted);
    font-style: italic;
    padding: 1rem;
}