:root {
  --bg: #0b0f17;
  --panel: #11192a;
  --text: #e9eefc;
  --muted: #9fb0d0;
  --accent: #5aa2ff;
  --accent2: #6cffc7;
  --border: rgba(255, 255, 255, 0.08);
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
  --radius: 18px;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --sans: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  font-family: var(--sans);
  background:
    radial-gradient(1200px 700px at 20% 15%, rgba(90, 162, 255, 0.18), transparent 60%),
    radial-gradient(900px 600px at 80% 0%, rgba(108, 255, 199, 0.12), transparent 55%),
    var(--bg);
  color: var(--text);
  min-height: 100vh;
  padding: 18px;
}
.app {
  width: min(1240px, 100%);
  margin: 0 auto;
  display: grid;
  gap: 14px;
}
.hero,
.panel {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0.03));
  box-shadow: var(--shadow);
}
.hero {
  padding: 18px;
}
.hero h1 {
  margin: 0 0 4px;
  font-size: 28px;
}
.hero p {
  margin: 0;
  color: rgba(233, 238, 252, 0.78);
}
.panel {
  padding: 14px;
}
.panel h2 {
  margin: 0 0 10px;
  font-size: 18px;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(165px, 1fr));
  gap: 10px;
}
.dist-group {
  margin-top: 10px;
}
.sup-block {
  display: grid;
  gap: 10px;
}
.is-hidden {
  display: none !important;
}
label {
  display: grid;
  gap: 5px;
  color: rgba(233, 238, 252, 0.72);
  font-size: 12px;
}
input,
select,
button {
  appearance: none;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 8px 10px;
  font-size: 14px;
  background: rgba(0, 0, 0, 0.18);
  color: var(--text);
}
input,
select {
  outline: none;
}
input:focus,
select:focus {
  border-color: rgba(90, 162, 255, 0.7);
  box-shadow: 0 0 0 4px rgba(90, 162, 255, 0.15);
}
select option {
  background: #0f1626;
  color: var(--text);
}
button {
  cursor: pointer;
  font-weight: 650;
  transition: transform 0.06s ease, border-color 0.15s ease, background 0.15s ease;
}
button:hover {
  border-color: rgba(255, 255, 255, 0.18);
  background: rgba(0, 0, 0, 0.24);
}
button:active {
  transform: translateY(1px);
}
.btn-link {
  text-decoration: none;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 8px 10px;
  font-size: 14px;
  background: rgba(0, 0, 0, 0.18);
  color: var(--text);
  font-weight: 650;
}
.btn-link:hover {
  border-color: rgba(255, 255, 255, 0.18);
  background: rgba(0, 0, 0, 0.24);
}
button.primary {
  border-color: rgba(90, 162, 255, 0.45);
  background: rgba(90, 162, 255, 0.14);
}
button.primary:hover {
  border-color: rgba(90, 162, 255, 0.8);
  background: rgba(90, 162, 255, 0.18);
}
.actions {
  margin-top: 10px;
  display: flex;
  gap: 8px;
}
.nav-rail {
  width: min(280px, 100%);
  border: 1px solid var(--border);
  border-radius: 14px;
  background: rgba(0, 0, 0, 0.16);
  padding: 10px;
}
.nav-rail-title {
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: rgba(233, 238, 252, 0.9);
  margin: 0;
}
.nav-rail-toggle {
  appearance: none;
  border: 1px solid var(--border);
  border-radius: 10px;
  min-width: 32px;
  min-height: 32px;
  padding: 0;
  font-size: 18px;
  line-height: 1;
  font-weight: 700;
  color: var(--text);
  background: rgba(0, 0, 0, 0.2);
  cursor: pointer;
}
.nav-rail-sections {
  display: grid;
  gap: 10px;
}
.nav-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.14);
  padding: 8px;
}
.nav-home-card {
  display: grid;
  gap: 8px;
}
.nav-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}
.nav-group {
  display: grid;
  gap: 6px;
}
.nav-group-title {
  color: rgba(233, 238, 252, 0.62);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: 700;
  padding: 0 2px;
}
.nav-rail-list {
  display: grid;
  gap: 8px;
}
.nav-rail-link {
  text-decoration: none;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px 12px;
  color: var(--text);
  background: rgba(0, 0, 0, 0.18);
  font-size: 14px;
  font-weight: 650;
  transition: border-color 0.15s ease, background 0.15s ease, transform 0.06s ease;
}
.nav-rail-link:hover {
  border-color: rgba(255, 255, 255, 0.18);
  background: rgba(0, 0, 0, 0.24);
}
.nav-rail-link:active {
  transform: translateY(1px);
}
.nav-rail-link.is-active {
  border-color: rgba(90, 162, 255, 0.38);
  background: linear-gradient(180deg, rgba(90, 162, 255, 0.22), rgba(90, 162, 255, 0.09));
}
.nav-rail.is-collapsed {
  width: 64px;
  padding: 10px 8px;
}
.nav-rail.is-collapsed .nav-card:not(.nav-home-card) {
  display: none;
}
.nav-rail.is-collapsed .nav-home-card .nav-rail-list,
.nav-rail.is-collapsed .nav-home-card .nav-rail-title {
  display: none;
}
.toggles {
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
}
.toggles label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: rgba(233, 238, 252, 0.88);
  font-size: 13px;
}
.toggles input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  margin: 0;
  padding: 0;
  border: 1px solid rgba(233, 238, 252, 0.45);
  border-radius: 4px;
  background: rgba(0, 0, 0, 0.28);
  position: relative;
  cursor: pointer;
}
.toggles input[type="checkbox"]::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 1px;
  width: 4px;
  height: 8px;
  border: solid #0b0f17;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
  opacity: 0;
}
.toggles input[type="checkbox"]:checked {
  background: var(--accent2);
  border-color: var(--accent2);
}
.toggles input[type="checkbox"]:checked::after {
  opacity: 1;
}
.status {
  margin: 8px 0 0;
  color: rgba(233, 238, 252, 0.78);
  min-height: 18px;
}
canvas {
  width: 100%;
  height: auto;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.18);
}
.note {
  margin: 8px 0 0;
  font-size: 12px;
  color: rgba(233, 238, 252, 0.62);
}
.equations pre {
  margin: 0;
  white-space: pre-wrap;
  font-family: var(--mono);
  font-size: 12px;
  color: rgba(233, 238, 252, 0.9);
  line-height: 1.5;
}
.eq-body {
  display: grid;
  gap: 6px;
  color: rgba(233, 238, 252, 0.9);
  font-size: 13px;
}
.eq-line {
  font-family: "Cambria Math", "STIX Two Math", "Times New Roman", serif;
  letter-spacing: 0.01em;
}
.eq-note {
  color: rgba(233, 238, 252, 0.72);
  font-size: 12px;
}
@media (max-width: 700px) {
  .hero h1 {
    font-size: 24px;
  }
}
@media (min-width: 1280px) {
  .nav-rail {
    position: fixed;
    left: 16px;
    top: 16px;
    z-index: 5;
  }
}