body { font-family: -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Arial; margin: 20px; color: #111; }
header { margin-bottom: 18px; padding: 10px 0; }
h1 { margin: 0 0 8px 0; font-size: 2.2rem; line-height: 1.05; font-weight: 700; }
p.lead { margin: 0 0 18px 0; color: #333; font-size: 1.05rem; max-width: 75ch; }
.controls { display: flex; flex-wrap: wrap; gap: 8px 12px; margin-bottom: 12px; }
/* removed centering: allow plot to span full width */
main { display: block; }
.control { display:flex; flex-direction:column; font-size:0.9rem; }
select { min-width: 160px; padding:6px 8px; border-radius:4px; border:1px solid #ccc; }
#plot { width: 100%; height: 90vh; border: 1px solid #eee; box-shadow: 0 1px 3px rgba(0,0,0,0.04); }
footer { margin-top: 14px; font-size:0.9rem; }
.small { font-size:0.85rem; color:#666 }
.actions { display:flex; gap:8px; align-items:center }
button { padding:6px 10px; border-radius:4px; border:1px solid #888; background:#f6f6f6; cursor:pointer }
/* prominent Y-axis selector placed above other filters */
.top-controls { margin: 12px 0 6px 0; display:flex; align-items:center; gap:12px; justify-content:flex-start; }
/* helper to force a line break inside the .top-controls flex row */
.break { flex-basis:100%; height:0 }
.y-control { background: linear-gradient(180deg,#fff,#f0fbff); padding:8px 12px; border-radius:8px; border:1px solid #cce; font-weight:600; box-shadow: 0 1px 2px rgba(0,0,0,0.04); }
.y-control select { font-weight:600; min-width:220px; padding:6px 8px; }
/* actions placed next to Y-axis for visibility */
.top-actions { display:flex; gap:8px; align-items:center; margin-left:8px; }
.marker-control { display:flex; align-items:center; gap:8px; font-size:0.95rem; color:#222; margin-left:6px; }
.marker-control input[type="range"] { vertical-align: middle; }
.top-actions button.primary { padding:8px 12px; border-radius:6px; border:1px solid #007bff; background:#007bff; color:#fff; font-weight:600; cursor:pointer; }
.top-actions button.secondary { padding:8px 12px; border-radius:6px; border:1px solid #007bff; background:#fff; color:#007bff; font-weight:600; cursor:pointer; }
.top-actions button:active { transform: translateY(1px); }