:root {
  --bg: #08111f;
  --panel: #101b2f;
  --panel-2: #15233b;
  --line: #273854;
  --text: #e6eefc;
  --muted: #9fb2cf;
  --cyan: #4de2ff;
  --cyan-dim: rgba(77, 226, 255, 0.15);
  --magenta: #ff79d7;
  --amber: #ffb14a;
  --green: #4ade80;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Avenir Next", "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at top left, rgba(77, 226, 255, 0.12), transparent 32%),
    radial-gradient(circle at top right, rgba(255, 121, 215, 0.14), transparent 26%),
    linear-gradient(180deg, #06101d, #0b1424 40%, #09111f);
  color: var(--text);
}

.app-container {
  max-width: 1480px;
  margin: 0 auto;
  padding: 18px;
}

.hero {
  margin-bottom: 18px;
  padding: 22px 24px;
  background: linear-gradient(135deg, rgba(16, 27, 47, 0.96), rgba(11, 19, 33, 0.96));
  border: 1px solid rgba(77, 226, 255, 0.16);
  border-radius: 22px;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.35);
}

.eyebrow {
  margin: 0 0 8px;
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan);
}

.hero h1 {
  margin: 0;
  font-size: clamp(1.9rem, 3vw, 3.1rem);
  line-height: 1.05;
}

.subtitle {
  max-width: 900px;
  margin: 12px 0 0;
  color: var(--muted);
  line-height: 1.7;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(320px, 430px);
  gap: 18px;
}

.stage-panel,
.card,
.edu-card {
  background: linear-gradient(180deg, rgba(16, 27, 47, 0.98), rgba(12, 21, 37, 0.98));
  border: 1px solid rgba(77, 226, 255, 0.1);
  border-radius: 20px;
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.25);
}

.stage-panel {
  padding: 18px;
}

.panel-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 18px;
  margin-bottom: 12px;
}

.panel-head.secondary {
  margin-top: 18px;
}

.panel-head h2 {
  margin: 0;
  font-size: 1.04rem;
}

.panel-head p,
.canvas-caption,
.small-note,
.edu-card p {
  margin: 6px 0 0;
  color: var(--muted);
  line-height: 1.6;
  font-size: 0.93rem;
}

.status-pill {
  min-width: 124px;
  padding: 7px 12px;
  border-radius: 999px;
  background: var(--cyan-dim);
  border: 1px solid rgba(77, 226, 255, 0.18);
  color: var(--cyan);
  text-align: center;
  font-size: 0.85rem;
}

.canvas-shell {
  overflow: hidden;
  border-radius: 18px;
  background:
    linear-gradient(180deg, rgba(5, 10, 18, 0.95), rgba(8, 14, 25, 0.95));
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.canvas-shell.large { height: 360px; }
.canvas-shell.medium { height: 250px; }

canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.control-panel {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.card {
  padding: 16px;
}

.card h3 {
  margin: 0 0 12px;
  font-size: 0.96rem;
}

.control-row,
.toggle-row {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: center;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 0.88rem;
}

.toggle-row {
  justify-content: flex-start;
  margin-top: 10px;
}

input[type="range"] {
  width: 100%;
  margin: 0 0 12px;
  accent-color: var(--cyan);
}

.gate-grid {
  display: grid;
  gap: 10px;
}

.gate-item {
  display: grid;
  gap: 6px;
}

.gate-label {
  font-size: 0.85rem;
  color: var(--muted);
}

.gate-bar {
  height: 10px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 999px;
  overflow: hidden;
}

.gate-fill {
  height: 100%;
  width: 0;
  transition: width 120ms linear;
}

.gate-fill.sodium { background: var(--cyan); }
.gate-fill.inactivation { background: var(--magenta); }
.gate-fill.potassium { background: var(--amber); }

.button-row {
  display: flex;
  gap: 8px;
  margin-bottom: 8px;
}

.action-btn,
.preset-btn {
  appearance: none;
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  border-radius: 12px;
  padding: 10px 12px;
  cursor: pointer;
  transition: transform 120ms ease, background 120ms ease, border-color 120ms ease;
}

.action-btn:hover,
.preset-btn:hover {
  transform: translateY(-1px);
  background: rgba(255, 255, 255, 0.07);
  border-color: rgba(77, 226, 255, 0.22);
}

.action-btn.primary {
  background: linear-gradient(135deg, var(--cyan), #3db8ff);
  color: #06101d;
  border: none;
  font-weight: 700;
}

.stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.stat-box {
  padding: 12px;
  border-radius: 14px;
  background: var(--panel-2);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.stat-box span {
  display: block;
  margin-bottom: 4px;
  color: var(--muted);
  font-size: 0.8rem;
}

.stat-box strong {
  font-size: 0.96rem;
}

.education {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 18px;
}

.edu-card {
  padding: 18px;
}

.edu-card h3 {
  margin: 0 0 8px;
  font-size: 0.98rem;
  color: var(--cyan);
}

@media (max-width: 1080px) {
  .layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .app-container {
    padding: 12px;
  }
  .canvas-shell.large {
    height: 300px;
  }
  .canvas-shell.medium {
    height: 220px;
  }
  .education {
    grid-template-columns: 1fr;
  }
  .stats-grid {
    grid-template-columns: 1fr;
  }
  .button-row {
    flex-wrap: wrap;
  }
}