:root {
  color-scheme: dark;
  --bg: #0b1020;
  --bg2: #070a14;
  --panel: rgba(15, 20, 35, 0.78);
  --panel2: rgba(15, 20, 35, 0.58);
  --stroke: rgba(255, 255, 255, 0.14);
  --text: #e8ecff;
  --muted: rgba(232, 236, 255, 0.72);
  --muted2: rgba(232, 236, 255, 0.55);
  --accent: #38bdf8;
  --accent2: #a371f7;
  --shadow: 0 18px 48px rgba(0, 0, 0, 0.35);
  --r: 16px;
}

* {
  box-sizing: border-box;
}

.hidden {
  display: none !important;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  background: radial-gradient(1200px 700px at 24% -10%, rgba(56, 189, 248, 0.18), transparent 70%),
    radial-gradient(900px 600px at 92% 6%, rgba(163, 113, 247, 0.16), transparent 70%),
    linear-gradient(180deg, var(--bg), var(--bg2));
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Helvetica Neue,
    Arial;
}

a {
  color: inherit;
  text-decoration: none;
}

.page {
  min-height: 100dvh;
  padding: 12px;
}

.topbar {
  max-width: 1140px;
  margin: 0 auto 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.back-home {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--stroke);
  background: var(--panel2);
  backdrop-filter: blur(10px);
  font-weight: 700;
  font-size: 12px;
}

.back-home:hover {
  border-color: rgba(56, 189, 248, 0.35);
}

.segmented {
  display: inline-flex;
  gap: 8px;
  flex-wrap: wrap;
}

.layout {
  max-width: 1140px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

@media (min-width: 1024px) {
  .layout {
    grid-template-columns: 1fr 340px;
    align-items: start;
  }
}

.stage,
.panel {
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: linear-gradient(180deg, var(--panel), var(--panel2));
  border-radius: 18px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.panel {
  padding: 14px;
  overflow: auto;
  max-height: 86vh;
}

.panel-head h1 {
  margin: 0;
  font-size: 16px;
  letter-spacing: 0.01em;
}

.muted {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

.controls {
  display: grid;
  gap: 10px;
  margin-top: 10px;
}

.stack {
  display: grid;
  gap: 10px;
}

.box {
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 14px;
  background: rgba(0, 0, 0, 0.12);
  padding: 12px;
}

.box-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 10px;
}

.box-title {
  font-size: 12px;
  font-weight: 700;
  color: rgba(232, 236, 255, 0.92);
}

.field label {
  display: block;
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 6px;
}

.row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.grid2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

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

.value {
  min-width: 56px;
  text-align: right;
  font-variant-numeric: tabular-nums;
  color: rgba(232, 236, 255, 0.92);
  font-size: 12px;
}

.value-inline {
  min-width: auto;
}

.hint {
  margin-top: 6px;
  font-size: 12px;
  color: var(--muted2);
  line-height: 1.5;
}

.check {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  font-size: 12px;
  color: var(--muted);
  user-select: none;
  cursor: pointer;
}

.btn,
.module-btn,
.shape-btn,
.mode-btn {
  appearance: none;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.09);
  color: var(--text);
  border-radius: 999px;
  padding: 10px 12px;
  font-size: 12px;
  font-weight: 650;
  cursor: pointer;
  transition: transform 0.06s ease, background 0.15s ease, border-color 0.15s ease;
  outline: none;
}

.btn:hover,
.module-btn:hover,
.shape-btn:hover,
.mode-btn:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(56, 189, 248, 0.25);
}

.btn:active,
.module-btn:active,
.shape-btn:active,
.mode-btn:active {
  transform: translateY(1px);
}

.btn.primary {
  border-color: rgba(56, 189, 248, 0.45);
  background: rgba(56, 189, 248, 0.16);
}

.module-btn.is-active {
  border-color: rgba(56, 189, 248, 0.55);
  box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.1);
}

.shape-btn.is-active,
.mode-btn.is-active {
  border-color: rgba(56, 189, 248, 0.55);
  background: rgba(56, 189, 248, 0.12);
}

.btn:focus-visible,
.module-btn:focus-visible,
.shape-btn:focus-visible,
.mode-btn:focus-visible,
input[type="range"]:focus-visible {
  outline: 3px solid rgba(56, 189, 248, 0.35);
  outline-offset: 2px;
}

.divider {
  height: 1px;
  background: rgba(255, 255, 255, 0.12);
  margin: 12px 0;
}

.h2 {
  margin: 0;
  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.01em;
}

.didactic {
  margin-top: 10px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

.didactic p {
  margin: 0 0 8px;
}

.metrics {
  margin-top: 10px;
  display: grid;
  gap: 8px;
}

.metric {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
}

.metric .k {
  color: var(--muted2);
  font-size: 12px;
}

.metric .v {
  color: rgba(232, 236, 255, 0.92);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
}

.lesson-prompt {
  font-size: 13px;
  color: rgba(232, 236, 255, 0.92);
  line-height: 1.55;
}

.canvas-wrap {
  width: 100%;
  height: clamp(320px, 62vh, 720px);
  background: #000;
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
}

@media (min-width: 1024px) {
  .canvas-wrap {
    height: calc(100dvh - 118px);
    min-height: 560px;
    max-height: 860px;
  }
}

@media (max-width: 540px) {
  .panel {
    max-height: none;
  }
  .value {
    min-width: 52px;
  }
}