* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
  --bg: #0a0d14; --surface: #11151f; --surface2: #1a1f2e;
  --border: #252b3d; --text: #dde2ee; --text-dim: #6b7590;
  --accent: #38bdf8; --accent2: #a78bfa; --accent3: #34d399;
  --radius: 10px;
}
body { background: var(--bg); color: var(--text); font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; line-height: 1.6; min-height: 100vh; }
.fz-container { max-width: 1440px; margin: 0 auto; padding: 20px; }
header { text-align: center; margin-bottom: 24px; }
header h1 { font-size: 1.55rem; background: linear-gradient(135deg, var(--accent), var(--accent2)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; margin-bottom: 6px; }
.subtitle { color: var(--text-dim); font-size: 0.9rem; max-width: 880px; margin: 0 auto; }
.main-layout { display: grid; grid-template-columns: 270px 1fr; gap: 20px; margin-bottom: 24px; }
.controls-panel { background: var(--surface); border-radius: var(--radius); padding: 16px; border: 1px solid var(--border); display: flex; flex-direction: column; gap: 12px; height: fit-content; max-height: calc(100vh - 100px); overflow-y: auto; }
.controls-panel::-webkit-scrollbar { width: 4px; }
.controls-panel::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }
.control-section h3 { font-size: 0.8rem; color: var(--accent); margin-bottom: 10px; text-transform: uppercase; letter-spacing: 0.5px; }
.control-group { margin-bottom: 8px; }
.control-group label { display: flex; justify-content: space-between; font-size: 0.75rem; color: var(--text-dim); margin-bottom: 3px; }
.control-group .val { color: var(--accent); font-weight: 600; }
input[type="range"] { width: 100%; height: 4px; -webkit-appearance: none; appearance: none; background: var(--border); border-radius: 2px; outline: none; }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 14px; height: 14px; border-radius: 50%; background: var(--accent); cursor: pointer; }
input[type="range"]::-moz-range-thumb { width: 14px; height: 14px; border-radius: 50%; background: var(--accent); cursor: pointer; border: none; }
.check-row { display: flex; align-items: center; gap: 8px; font-size: 0.78rem; color: var(--text-dim); margin-bottom: 6px; cursor: pointer; }
.check-row input { width: 14px; height: 14px; accent-color: var(--accent); cursor: pointer; }
.mode-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 4px; }
.mode-btn { padding: 7px 4px; border: 1px solid var(--border); border-radius: 6px; background: var(--surface2); color: var(--text-dim); font-size: 0.68rem; cursor: pointer; transition: all 0.2s; text-align: center; }
.mode-btn:hover { background: var(--border); color: var(--text); }
.mode-btn.active { background: var(--accent2); color: #fff; border-color: var(--accent2); }
.preset-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 4px; }
.preset-btn { padding: 6px 4px; border: 1px solid var(--border); border-radius: 6px; background: var(--surface2); color: var(--text-dim); font-size: 0.7rem; cursor: pointer; transition: all 0.2s; }
.preset-btn:hover { background: var(--border); color: var(--text); }
.preset-btn.active { background: var(--accent); color: #04293a; border-color: var(--accent); }
.btn-row { display: flex; gap: 6px; }
.action-btn { flex: 1; padding: 8px 10px; border: 1px solid var(--border); border-radius: 6px; background: var(--surface2); color: var(--text); font-size: 0.78rem; cursor: pointer; transition: all 0.2s; }
.action-btn:hover { background: var(--border); }
.action-btn.active { background: var(--accent3); color: #04241a; border-color: var(--accent3); }
.stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.stat-item { background: var(--surface2); padding: 6px; border-radius: 6px; text-align: center; }
.stat-item .stat-label { display: block; font-size: 0.58rem; color: var(--text-dim); text-transform: uppercase; }
.stat-item .stat-val { display: block; font-size: 0.88rem; font-weight: 700; color: var(--accent); margin-top: 1px; }
.display-panel { min-width: 0; }
.viz-grid { display: grid; grid-template-columns: 2fr 1fr; grid-template-rows: auto auto; gap: 16px; }
.canvas-card { background: var(--surface); border-radius: var(--radius); border: 1px solid var(--border); padding: 14px; overflow: hidden; }
.canvas-card.main-2d { grid-row: 1 / 3; }
.canvas-card h3 { font-size: 0.78rem; color: var(--text-dim); margin-bottom: 10px; text-transform: uppercase; letter-spacing: 0.5px; }
.canvas-card canvas { width: 100%; display: block; border-radius: 6px; background: #050810; }
#zone-canvas { height: 460px; }
#intensity-canvas { height: 220px; }
#screen-canvas { height: 220px; }
.formula-box { background: var(--surface2); border-radius: 8px; padding: 10px 12px; margin-top: 10px; font-family: 'Cambria Math', Georgia, serif; text-align: center; color: var(--accent); font-size: 0.78rem; border: 1px solid var(--border); }
.education { background: var(--surface); border-radius: var(--radius); border: 1px solid var(--border); padding: 20px; margin-bottom: 20px; }
.tabs { display: flex; gap: 4px; margin-bottom: 16px; border-bottom: 1px solid var(--border); padding-bottom: 8px; flex-wrap: wrap; }
.tab-btn { padding: 8px 16px; border: none; background: transparent; color: var(--text-dim); font-size: 0.85rem; cursor: pointer; border-radius: 6px 6px 0 0; transition: all 0.2s; }
.tab-btn:hover { color: var(--text); }
.tab-btn.active { color: var(--accent); background: var(--surface2); font-weight: 600; }
.tab-pane { display: none; }
.tab-pane.active { display: block; }
.edu-card { background: var(--surface2); border-radius: 8px; padding: 16px; margin-bottom: 12px; }
.edu-card:last-child { margin-bottom: 0; }
.edu-card h3 { color: var(--accent); font-size: 0.95rem; margin-bottom: 8px; }
.edu-card p { font-size: 0.85rem; line-height: 1.7; color: var(--text-dim); }
footer { text-align: center; color: var(--text-dim); font-size: 0.75rem; padding: 12px 0; }
@media (max-width: 900px) {
  .main-layout { grid-template-columns: 1fr; }
  .viz-grid { grid-template-columns: 1fr; }
  .canvas-card.main-2d { grid-row: auto; }
  #zone-canvas { height: 340px; }
  .controls-panel { flex-direction: row; flex-wrap: wrap; max-height: none; }
  .control-section { flex: 1; min-width: 200px; }
}
@media (max-width: 600px) {
  .fz-container { padding: 10px; }
  header h1 { font-size: 1.15rem; }
  #zone-canvas { height: 280px; }
}