:root {
    --bg: #1a1a2e;
    --bg-card: #16213e;
    --text: #e0e0e0;
    --text-dim: #888;
    --accent: #0f3460;
    --accent-bright: #4fc3f7;
    --green: #4caf50;
    --red: #f44336;
    --yellow: #ff9800;
}

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

body {
    font-family: 'Segoe UI', system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
}

header {
    background: var(--bg-card);
    padding: 12px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #333;
}

header h1 {
    font-size: 1.2em;
    color: var(--accent-bright);
}

#status-bar {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 0.9em;
}

.status-dot {
    display: inline-block;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--red);
}

.status-dot.connected { background: var(--green); }

nav {
    background: var(--accent);
    display: flex;
}

nav a {
    flex: 1;
    text-align: center;
    padding: 10px;
    color: var(--text-dim);
    text-decoration: none;
    font-size: 0.95em;
    transition: all 0.2s;
}

nav a:hover { background: rgba(255,255,255,0.1); }
nav a.active { color: var(--accent-bright); border-bottom: 2px solid var(--accent-bright); }

main { padding: 16px; }

.tab-content { display: none; }
.tab-content.active { display: block; }

.chart-container {
    background: var(--bg-card);
    border-radius: 8px;
    padding: 12px;
    margin-bottom: 12px;
}

.controls {
    display: flex;
    gap: 12px;
    margin-bottom: 12px;
    align-items: center;
}

.controls label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.9em;
    color: var(--text-dim);
    cursor: pointer;
}

.controls button {
    background: var(--accent);
    color: var(--text);
    border: 1px solid #444;
    padding: 6px 14px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85em;
}

.controls button:hover { background: var(--accent-bright); color: #000; }

#isotopes-table, #peaks-table {
    background: var(--bg-card);
    border-radius: 8px;
    padding: 12px;
}

.isotope-row {
    display: flex;
    justify-content: space-between;
    padding: 6px 0;
    border-bottom: 1px solid #333;
    font-size: 0.9em;
}

.isotope-row:last-child { border-bottom: none; }
.isotope-name { color: var(--accent-bright); font-weight: bold; min-width: 80px; }
.isotope-prob { color: var(--green); min-width: 60px; }
.isotope-activity { color: var(--text-dim); }

.bg-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin-bottom: 12px;
}

.bg-stat {
    background: var(--bg-card);
    border-radius: 8px;
    padding: 12px;
    text-align: center;
}

.bg-stat-value { font-size: 1.4em; color: var(--accent-bright); }
.bg-stat-label { font-size: 0.8em; color: var(--text-dim); }

.history-item {
    background: var(--bg-card);
    border-radius: 8px;
    padding: 12px;
    margin-bottom: 8px;
    cursor: pointer;
    transition: background 0.2s;
}

.history-item:hover { background: #1e2a4a; }

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.history-date { font-weight: bold; color: var(--accent-bright); }
.history-cps { color: var(--text-dim); }
.history-isotopes { color: var(--green); font-size: 0.85em; }
.history-details { margin-top: 8px; padding-top: 8px; border-top: 1px solid #333; font-size: 0.9em; display: none; }
.history-details.open { display: block; }

.peak-row {
    display: flex;
    justify-content: space-between;
    padding: 4px 0;
    font-size: 0.85em;
}

@media (max-width: 600px) {
    .bg-stats { grid-template-columns: repeat(2, 1fr); }
    header { flex-direction: column; gap: 8px; }
    nav a { font-size: 0.85em; padding: 8px; }
}